refactor(annotate): drop HF Inference Providers code path

Default backend is now a local OpenAI-compatible server (vllm /
transformers) which auto_serve spawns. Removes the
use_hf_inference_providers config flag and the router.huggingface.co
routing branch.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.github/workflows/documentation-upload-pr.yml

@@ -33,7 +33,7 @@ jobs:
       github.event.workflow_run.event == 'pull_request' &&
       github.event.workflow_run.conclusion == 'success' &&
       github.repository == 'huggingface/lerobot'
-    uses: huggingface/doc-builder/.github/workflows/upload_pr_documentation.yml@2430c1ec91d04667414e2fa31ecfc36c153ea391  # main
+    uses: huggingface/doc-builder/.github/workflows/upload_pr_documentation.yml@9ad2de8582b56c017cb530c1165116d40433f1c6  # main
     with:
       package_name: lerobot
     secrets:

.github/workflows/documentation.yml

@@ -55,7 +55,7 @@ jobs:
       github.repository == 'huggingface/lerobot'
     permissions:
       contents: read
-    uses: huggingface/doc-builder/.github/workflows/build_main_documentation.yml@2430c1ec91d04667414e2fa31ecfc36c153ea391  # main
+    uses: huggingface/doc-builder/.github/workflows/build_main_documentation.yml@90b4ee2c10b81b5c1a6367c4e6fc9e2fb510a7e3  # main
     with:
       commit_sha: ${{ github.sha }}
       package: lerobot
@@ -78,7 +78,7 @@ jobs:
     permissions:
       contents: read
       pull-requests: write
-    uses: huggingface/doc-builder/.github/workflows/build_pr_documentation.yml@2430c1ec91d04667414e2fa31ecfc36c153ea391  # main
+    uses: huggingface/doc-builder/.github/workflows/build_pr_documentation.yml@90b4ee2c10b81b5c1a6367c4e6fc9e2fb510a7e3  # main
     with:
       commit_sha: ${{ github.event.pull_request.head.sha }}
       pr_number: ${{ github.event.number }}

AGENTS.md

@@ -1,7 +1,5 @@
 This file provides guidance to AI agents when working with code in this repository.
 
-> **User-facing help → [`AGENT_GUIDE.md`](./AGENT_GUIDE.md)** (SO-101 setup, recording, picking a policy, training duration, eval — with copy-pasteable commands).
-
 ## Project Overview
 
 LeRobot is a PyTorch-based library for real-world robotics, providing datasets, pretrained policies, and tools for training, evaluation, data collection, and robot control. It integrates with Hugging Face Hub for model/dataset sharing.

AGENT_GUIDE.md

@@ -1,410 +0,0 @@
-# AGENT_GUIDE.md — LeRobot Helper for AI Agents & Users
-
-This file is a practical, copy-paste-friendly companion for any AI agent (Cursor, Claude, ChatGPT, Codex, etc.) helping a user work with LeRobot. It complements [`AGENTS.md`](./AGENTS.md) (dev/contributor context) with **user-facing guidance**: how to start, what to train, how long, how to record, and how to calibrate an SO-101.
-
----
-
-## 1. Start here — ask the user first (MANDATORY)
-
-Before suggesting any command, an agent MUST ask the user at least these questions and wait for answers:
-
-1. **What's your goal?** (e.g. "teach my SO-101 to fold a cloth", "train a policy on an existing HF dataset", "contribute a PR", "understand the codebase")
-2. **What hardware do you have?**
-   - Robot: none / SO-100 / SO-101 / Koch / LeKiwi / Reachy / other
-   - Teleop: leader arm / phone / keyboard / gamepad / none
-   - Cameras: how many, resolution, fixed or moving?
-3. **What machine will you train on?**
-   - GPU model + VRAM (e.g. "laptop 3060 6 GB", "RTX 4090 24 GB", "A100 80 GB", "CPU only")
-   - OS: macOS / Linux / Windows
-4. **Skill level & time budget?** First time, some ML, experienced? Hours, days, a weekend?
-5. **Do you already have a dataset?** Yes (HF repo id?) / no / want to record one
-6. **How can I help right now?** (pick one concrete next step)
-
-Only after you have answers, propose a concrete path. If something is ambiguous, ask again rather than guessing. Bias toward **the simplest thing that works** for the user's hardware and goal.
-
----
-
-## 2. LeRobot in 60 seconds
-
-LeRobot = **datasets + policies + envs + robot control**, unified by a small set of strong abstractions.
-
-- **`LeRobotDataset`** — episode-aware dataset (video or images + actions + state), loadable from the Hub or disk.
-- **Policies** (`ACT`, `Diffusion`, `SmolVLA`, `π0`, `π0.5`, `Wall-X`, `X-VLA`, `VQ-BeT`, `TD-MPC`, …) — all inherit `PreTrainedPolicy` and can be pushed/pulled from the Hub.
-- **Processors** — small composable transforms between dataset → policy → robot.
-- **Envs** (sim) and **Robots** (real) — same action/observation contract so code swaps cleanly.
-- **CLI** — `lerobot-record`, `lerobot-train`, `lerobot-eval`, `lerobot-teleoperate`, `lerobot-calibrate`, `lerobot-find-port`, `lerobot-setup-motors`, `lerobot-replay`.
-
-See [`AGENTS.md`](./AGENTS.md) for repo architecture.
-
----
-
-## 3. Quickstart paths (pick one)
-
-### Path A — "I have an SO-101 and want my first trained policy"
-
-Go to §4 (SO-101 end-to-end), then §5 (data tips), then §6 (pick a policy — likely **ACT**), then §7 (how long), then §8 (eval).
-
-### Path B — "No hardware, I want to train on an existing dataset"
-
-Skip §4. Pick a policy in §6, pick a duration in §7, then run `lerobot-train` per §4.9 with a Hub `--dataset.repo_id` and an `--env.type` for eval. Finish with §8.
-
-### Path C — "I just want to understand the codebase"
-
-Read §2 above, then `AGENTS.md` "Architecture", then open `src/lerobot/policies/act/` and `src/lerobot/datasets/lerobot_dataset.py` as canonical examples.
-
----
-
-## 4. SO-101 end-to-end cheat-sheet
-
-Full details in [`docs/source/so101.mdx`](./docs/source/so101.mdx) and [`docs/source/il_robots.mdx`](./docs/source/il_robots.mdx). Minimum commands in order. Confirm arms are assembled + powered before issuing.
-
-**4.1 Install**
-
-```bash
-pip install 'lerobot[feetech]'              # SO-100/SO-101 motor stack
-# pip install 'lerobot[all]'                # everything
-# pip install 'lerobot[aloha,pusht]'        # specific features
-# pip install 'lerobot[smolvla]'            # add SmolVLA deps
-git lfs install && git lfs pull
-hf auth login                               # required to push datasets/policies
-```
-
-Contributors can alternatively use `uv sync --locked --extra feetech` (see `AGENTS.md`).
-
-**4.2 Find USB ports** — run once per arm, unplug when prompted.
-
-```bash
-lerobot-find-port
-```
-
-macOS: `/dev/tty.usbmodem...`; Linux: `/dev/ttyACM0` (may need `sudo chmod 666 /dev/ttyACM0`).
-
-**4.3 Setup motor IDs & baudrate** (one-time, per arm)
-
-```bash
-lerobot-setup-motors --robot.type=so101_follower --robot.port=<FOLLOWER_PORT>
-lerobot-setup-motors --teleop.type=so101_leader  --teleop.port=<LEADER_PORT>
-```
-
-**4.4 Calibrate** — center all joints, press Enter, sweep each joint through its full range. The `id` is the calibration key — reuse it everywhere.
-
-```bash
-lerobot-calibrate --robot.type=so101_follower --robot.port=<FOLLOWER_PORT> --robot.id=my_follower
-lerobot-calibrate --teleop.type=so101_leader  --teleop.port=<LEADER_PORT>   --teleop.id=my_leader
-```
-
-**4.5 Teleoperate** (sanity check, no recording)
-
-```bash
-lerobot-teleoperate \
-  --robot.type=so101_follower --robot.port=<FOLLOWER_PORT> --robot.id=my_follower \
-  --teleop.type=so101_leader  --teleop.port=<LEADER_PORT>  --teleop.id=my_leader \
-  --robot.cameras="{ front: {type: opencv, index_or_path: 0, width: 640, height: 480, fps: 30}}" \
-  --display_data=true
-```
-
-> **Feetech timeout / comms error on SO-100 / SO-101?** Before touching software, check the **red motor LEDs** on the daisy chain.
->
-> - **All steady red, gripper → base chain** → wiring OK.
-> - **One or more motors dark / chain stops mid-way** → wiring issue: reseat the 3-pin cables, check the controller-board power supply, and make sure each motor is fully clicked in.
-> - **LEDs blinking** → the motor is in an **error state**: usually overload (forcing a joint past its limit) **or wrong power supply voltage**. SO-100 / SO-101 ship in two variants — a **5 V / 7.4 V** build and a **12 V** build — they are NOT interchangeable. Using a 12 V PSU on a 5 V / 7.4 V arm (or vice-versa) will trip this error; confirm your motor variant before powering up.
->
-> Most "timeout" errors are physical, not code.
-
-**4.6 Record a dataset** — keys: **→** next, **←** redo, **ESC** finish & upload.
-
-```bash
-HF_USER=$(NO_COLOR=1 hf auth whoami | awk -F': *' 'NR==1 {print $2}')
-
-lerobot-record \
-  --robot.type=so101_follower --robot.port=<FOLLOWER_PORT> --robot.id=my_follower \
-  --teleop.type=so101_leader  --teleop.port=<LEADER_PORT>  --teleop.id=my_leader \
-  --robot.cameras="{ front: {type: opencv, index_or_path: 0, width: 640, height: 480, fps: 30}}" \
-  --dataset.repo_id=${HF_USER}/my_task \
-  --dataset.single_task="<describe the task in one sentence>" \
-  --dataset.num_episodes=50 \
-  --dataset.episode_time_s=30 \
-  --dataset.reset_time_s=10 \
-  --display_data=true
-```
-
-**4.7 Visualize** — **always** do this before training. Look for missing frames, camera blur, unreachable targets, inconsistent object positions.
-After upload: https://huggingface.co/spaces/lerobot/visualize_dataset → paste `${HF_USER}/my_task`. Works for **any LeRobot-formatted Hub dataset** — use it to scout other datasets, inspect episode quality, or debug your own data before retraining.
-
-**4.8 Replay an episode** (sanity check)
-
-```bash
-lerobot-replay --robot.type=so101_follower --robot.port=<FOLLOWER_PORT> --robot.id=my_follower \
-  --dataset.repo_id=${HF_USER}/my_task --dataset.episode=0
-```
-
-**4.9 Train** (default: ACT — fastest, lowest memory). Apple silicon: `--policy.device=mps`. See §6/§7 for policy and duration.
-
-```bash
-lerobot-train \
-  --dataset.repo_id=${HF_USER}/my_task \
-  --policy.type=act \
-  --policy.device=cuda \
-  --output_dir=outputs/train/act_my_task \
-  --job_name=act_my_task \
-  --batch_size=8 \
-  --wandb.enable=true \
-  --policy.repo_id=${HF_USER}/act_my_task
-```
-
-**4.10 Evaluate on the real robot** — compare success rate to a teleoperated baseline.
-
-```bash
-lerobot-record \
-  --robot.type=so101_follower --robot.port=<FOLLOWER_PORT> --robot.id=my_follower \
-  --robot.cameras="{ front: {type: opencv, index_or_path: 0, width: 640, height: 480, fps: 30}}" \
-  --dataset.repo_id=${HF_USER}/eval_my_task \
-  --dataset.single_task="<same task description as training>" \
-  --dataset.num_episodes=10 \
-  --policy.path=${HF_USER}/act_my_task
-```
-
----
-
-## 5. Data collection tips (beginner → reliable policy)
-
-Good data beats clever models. Adopt these defaults and deviate only with evidence.
-
-### 5.1 Setup & ergonomics
-
-- **Fix the rig and cameras** before touching the software. If the rig vibrates or the operator gets frustrated, fix that first — more bad data won't help.
-- **Lighting matters more than resolution.** Diffuse, consistent light. Avoid moving shadows.
-- **"Can you do the task from the camera view alone?"** If no, your cameras are wrong. Fix before recording.
-- Enable **action interpolation** for rollouts when available for smoother trajectories.
-
-### 5.2 Practice before you record
-
-- Do 5–10 demos without recording. Build a deliberate, repeatable strategy.
-- Hesitant or inconsistent demos teach the model hesitation.
-
-### 5.3 Quality over speed
-
-Deliberate, high-quality execution beats fast sloppy runs. Optimize for speed only **after** strategy is dialed in — never trade quality for it.
-
-### 5.4 Consistency within and across episodes
-
-Same grasp, approach vector, and timing. Coherent strategies are much easier to learn than wildly varying movements.
-
-### 5.5 Start small, then extend (the golden rule)
-
-- **First 50 episodes = constrained version** of the task: one object, fixed position, fixed camera setup, one operator.
-- Train a quick ACT model. See what fails.
-- **Then add diversity** along one axis at a time: more positions → more lighting → more objects → more operators.
-- Don't try to collect the "perfect dataset" on day one. Iterate.
-
-### 5.6 Policy choice for beginners
-
-- **Laptop / first time / want results fast → ACT.** Works surprisingly well, trains fast even on a laptop GPU.
-- **Bigger GPU / language-conditioned / multi-task → SmolVLA.** Unfreezing the vision encoder (see §7) is a big win here.
-- Defer π0 / π0.5 / Wall-X / X-VLA until you have a proven ACT baseline and a 20+ GB GPU.
-
-### 5.7 Recommended defaults for your first task
-
-| Setting          | Value                                                                                                                                                 |
-| ---------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------- |
-| Episodes         | **50** to start, scale to 100–300 after first training                                                                                                |
-| Episode length   | 20–45 s (shorter is fine for grasp/place)                                                                                                             |
-| Reset time       | 10 s                                                                                                                                                  |
-| FPS              | 30                                                                                                                                                    |
-| Cameras          | **2 cameras recommended**: 1 fixed front + 1 wrist. Multi-view often outperforms single-view. A single fixed camera also works to keep things simple. |
-| Task description | Short, specific, action-phrased sentence                                                                                                              |
-
-### 5.8 Troubleshooting signal
-
-- Policy fails at one specific stage → record 10–20 more episodes **targeting that stage**.
-- Policy flaps / oscillates → likely inconsistent demos, or need more training; re-record worst episodes (use **←** to redo).
-- Policy ignores the object → camera framing or lighting issue, not a model issue.
-
-See also: [What makes a good dataset](https://huggingface.co/blog/lerobot-datasets#what-makes-a-good-dataset).
-
----
-
-## 6. Which policy should I train?
-
-Match the policy to the user's **GPU memory** and **time budget**. Numbers below come from an internal profiling run (one training update per policy). They are **indicative only** — see caveats.
-
-### 6.1 Profiling snapshot (indicative)
-
-All policies typically train for **5–10 epochs** (see §7).
-
-| Policy      | Batch | Update (ms) | Peak GPU mem (GB) | Best for                                                                                         |
-| ----------- | ----: | ----------: | ----------------: | ------------------------------------------------------------------------------------------------ |
-| `act`       |     4 |    **83.9** |          **0.94** | First-time users, laptops, single-task. Fast and reliable.                                       |
-| `diffusion` |     4 |       168.6 |              4.94 | Multi-modal action distributions; needs mid-range GPU.                                           |
-| `smolvla`   |     1 |       357.8 |              3.93 | Language-conditioned, multi-task, small VLA. **Unfreeze vision encoder for big gains** (see §7). |
-| `xvla`      |     1 |       731.6 |             15.52 | Large VLA, multi-task.                                                                           |
-| `wall_x`    |     1 |       716.5 |             15.95 | Large VLA with world-model objective.                                                            |
-| `pi0`       |     1 |       940.3 |             15.50 | Strong large VLA baseline (Physical Intelligence).                                               |
-| `pi05`      |     1 |      1055.8 |             16.35 | Newer π policy; similar footprint to `pi0`.                                                      |
-
-**Critical caveats:**
-
-- **Optimizer:** measured with **SGD**. LeRobot's default is **AdamW**, which keeps extra optimizer state → **peak memory will be noticeably higher** with the default, especially for `pi0`, `pi05`, `wall_x`, `xvla`.
-- **Batch size:** the large policies were profiled at batch 1. In practice use a **larger batch** for stable training (see §7.4). Memory scales roughly linearly with batch.
-
-### 6.2 Decision rules
-
-- **< 8 GB VRAM (laptop, 3060, M-series Mac):** → `act`. Maybe `diffusion` if you have ~6–8 GB free.
-- **12–16 GB VRAM (4070/4080, A4000):** → `smolvla` with defaults, or `act`/`diffusion` with larger batch. `pi0`/`pi05`/`wall_x`/`xvla` feasible only with small batch + gradient accumulation.
-- **24+ GB VRAM (3090/4090/A5000):** → any policy. Prefer `smolvla` (unfrozen) for multi-task; `act` for single-task grasp-and-place (still often the best ROI). Could experiment with `pi0` or `pi05` or `xvla`
-- **80 GB (A100/H100):** → any, with healthy batch. `pi05`, `xvla`, `wall_x` become comfortable.
-- **CPU only:** → don't train here. Use Google Colab (see [`docs/source/notebooks.mdx`](./docs/source/notebooks.mdx)) or a rented GPU.
-
----
-
-## 7. How long should I train?
-
-Robotics imitation learning usually converges in a **few epochs over the dataset**, not hundreds of thousands of raw steps. Think **epochs first**, then translate to steps.
-
-### 7.1 Rule of thumb
-
-- **Typical total: 5–10 epochs.** Start at 5, eval, then decide if more helps.
-- Very small datasets (< 30 episodes) may want slightly more epochs — but first, **collect more data**.
-- VLAs with a pretrained vision backbone typically need **fewer** epochs than training from scratch.
-
-### 7.2 Steps ↔ epochs conversion
-
-```
-total_frames     = sum of frames over all episodes      # e.g. 50 eps × 30 fps × 30 s ≈ 45,000
-steps_per_epoch  = ceil(total_frames / batch_size)
-total_steps      = epochs × steps_per_epoch
-```
-
-Examples for `--batch_size=8`:
-
-| Dataset size            |  Frames | Steps / epoch | 5 epochs | 10 epochs |
-| ----------------------- | ------: | ------------: | -------: | --------: |
-| 50 eps × 30 s @ 30 fps  |  45,000 |        ~5,625 |      28k |       56k |
-| 100 eps × 30 s @ 30 fps |  90,000 |       ~11,250 |      56k |      113k |
-| 300 eps × 30 s @ 30 fps | 270,000 |       ~33,750 |     169k |      338k |
-
-Pass the resulting total with `--steps=<N>`; eval at intermediate checkpoints (`outputs/train/.../checkpoints/`).
-
-### 7.3 Per-policy starting points (single-task, ~50 episodes)
-
-| Policy         | Batch | Steps (first run) | Notes                                                             |
-| -------------- | ----: | ----------------: | ----------------------------------------------------------------- |
-| `act`          |  8–16 |           30k–80k | Usually converges under 50k for single-task.                      |
-| `diffusion`    |  8–16 |          80k–150k | Benefits from longer training than ACT.                           |
-| `smolvla`      |   4–8 |           30k–80k | Pretrained VLM → converges fast.                                  |
-| `pi0` / `pi05` |   1–4 |           30k–80k | Memory-bound; use gradient accumulation for effective batch ≥ 16! |
-
-### 7.4 Batch size guidance
-
-- **Bigger batch is preferable** for stable gradients on teleop data.
-- If GPU memory is the bottleneck, use **gradient accumulation** to raise _effective_ batch without raising peak memory.
-- Scale **learning rate** gently with batch; most LeRobot defaults work fine for a 2–4× batch change.
-
-### 7.5 Scale LR schedule & checkpoints with `--steps`
-
-LeRobot's default schedulers (e.g. SmolVLA's cosine decay) use `scheduler_decay_steps=30_000`, which is sized for long training runs. When you shorten training (e.g. 5k–10k steps on a small dataset), **scale the scheduler down to match** — otherwise the LR stays near the peak and never decays. Same for checkpoint frequency.
-
-```bash
-lerobot-train ... \
-  --steps=5000 \
-  --policy.scheduler_decay_steps=5000 \
-  --save_freq=5000
-```
-
-Rule of thumb: set `scheduler_decay_steps ≈ steps`, and `save_freq` to whatever granularity you want for eval (e.g. every 1k–5k steps). Match `scheduler_warmup_steps` proportionally if your run is very short.
-
-### 7.6 SmolVLA: unfreeze the vision encoder for real gains
-
-SmolVLA ships with `freeze_vision_encoder=True`. Unfreezing usually **improves performance substantially** on specialized tasks, at the cost of more VRAM and slower steps. Enable with:
-
-```bash
-lerobot-train ... --policy.type=smolvla \
-  --policy.freeze_vision_encoder=false \
-  --policy.train_expert_only=false
-```
-
-### 7.7 Signals to stop / keep going
-
-- Train loss plateaus → stop, save a Hub checkpoint.
-- Train loss still dropping and you're under 10 epochs → keep going.
-
----
-
-## 8. Evaluation & benchmarks
-
-Two flavors of evaluation:
-
-### 8.1 Real-robot eval (SO-101, etc.)
-
-Reuse `lerobot-record` with `--policy.path` to run the trained policy on-robot and save the run as an eval dataset. Convention: prefix the dataset with `eval_`.
-
-```bash
-lerobot-record \
-  --robot.type=so101_follower --robot.port=<FOLLOWER_PORT> --robot.id=my_follower \
-  --robot.cameras="{ front: {type: opencv, index_or_path: 0, width: 640, height: 480, fps: 30}}" \
-  --dataset.repo_id=${HF_USER}/eval_my_task \
-  --dataset.single_task="<same task description used during training>" \
-  --dataset.num_episodes=10 \
-  --policy.path=${HF_USER}/act_my_task
-```
-
-Report success rate across episodes. Compare to a teleoperated baseline and to an earlier checkpoint to catch regressions.
-
-### 8.2 Sim-benchmark eval
-
-For policies trained on sim datasets (PushT, Aloha, LIBERO, MetaWorld, RoboCasa, …) use `lerobot-eval` against the matching `env.type`:
-
-```bash
-lerobot-eval \
-  --policy.path=${HF_USER}/diffusion_pusht \
-  --env.type=pusht \
-  --eval.n_episodes=50 \
-  --eval.batch_size=10 \
-  --policy.device=cuda
-```
-
-- Use `--policy.path=outputs/train/.../checkpoints/<step>/pretrained_model` for local checkpoints.
-- `--eval.n_episodes` should be ≥ 50 for a stable success-rate estimate.
-- Available envs live in `src/lerobot/envs/`. See [`docs/source/libero.mdx`](./docs/source/libero.mdx), [`metaworld.mdx`](./docs/source/metaworld.mdx), [`robocasa.mdx`](./docs/source/robocasa.mdx), [`vlabench.mdx`](./docs/source/vlabench.mdx) for specific benchmarks.
-- To add a new benchmark, see [`docs/source/adding_benchmarks.mdx`](./docs/source/adding_benchmarks.mdx) and [`envhub.mdx`](./docs/source/envhub.mdx).
-
-### 8.2b Dockerfiles for benchmark eval
-
-Benchmark envs have native dependencies that are painful to install locally. The repo ships **pre-baked Dockerfiles** for each supported benchmark — use these to run `lerobot-eval` in a reproducible environment:
-
-| Benchmark   | Dockerfile                                                                             |
-| ----------- | -------------------------------------------------------------------------------------- |
-| LIBERO      | [`docker/Dockerfile.benchmark.libero`](./docker/Dockerfile.benchmark.libero)           |
-| LIBERO+     | [`docker/Dockerfile.benchmark.libero_plus`](./docker/Dockerfile.benchmark.libero_plus) |
-| MetaWorld   | [`docker/Dockerfile.benchmark.metaworld`](./docker/Dockerfile.benchmark.metaworld)     |
-| RoboCasa    | [`docker/Dockerfile.benchmark.robocasa`](./docker/Dockerfile.benchmark.robocasa)       |
-| RoboCerebra | [`docker/Dockerfile.benchmark.robocerebra`](./docker/Dockerfile.benchmark.robocerebra) |
-| RoboMME     | [`docker/Dockerfile.benchmark.robomme`](./docker/Dockerfile.benchmark.robomme)         |
-| RoboTwin    | [`docker/Dockerfile.benchmark.robotwin`](./docker/Dockerfile.benchmark.robotwin)       |
-| VLABench    | [`docker/Dockerfile.benchmark.vlabench`](./docker/Dockerfile.benchmark.vlabench)       |
-
-Build and run (adapt to your benchmark):
-
-```bash
-docker build -f docker/Dockerfile.benchmark.robomme -t lerobot-bench-robomme .
-docker run --gpus all --rm -it \
-  -v $HOME/.cache/huggingface:/root/.cache/huggingface \
-  lerobot-bench-robomme \
-  lerobot-eval --policy.path=<your_policy> --env.type=<env> --eval.n_episodes=50
-```
-
-See [`docker/README.md`](./docker/README.md) for base-image details.
-
-### 8.3 Target success rates
-
-Single-task grasp-and-place with 50 clean episodes: ACT should reach **> 70% success** on the training configuration. Less → data problem (see §5), not model problem. Expect a drop when generalizing to new positions — scale episodes or diversity to recover.
-
----
-
-## 9. Further reading & resources
-
-- **Getting started:** [`installation.mdx`](./docs/source/installation.mdx) · [`il_robots.mdx`](./docs/source/il_robots.mdx) · [What makes a good dataset](https://huggingface.co/blog/lerobot-datasets)
-- **Per-policy docs:** browse [`docs/source/*.mdx`](./docs/source/) (policies, hardware, benchmarks, advanced training).
-- **Community:** [Discord](https://discord.com/invite/s3KuuzsPFb) · [Hub `LeRobot` tag](https://huggingface.co/datasets?other=LeRobot) · [Dataset visualizer](https://huggingface.co/spaces/lerobot/visualize_dataset)
-
-> Keep this file current. If you learn a rule that would prevent a class of user mistakes, add it here and in [`AGENTS.md`](./AGENTS.md).

MANIFEST.in

@@ -1,4 +1,3 @@
 include src/lerobot/templates/lerobot_modelcard_template.md
-include src/lerobot/templates/lerobot_rewardmodel_modelcard_template.md
 include src/lerobot/datasets/card_template.md
 include src/lerobot/envs/metaworld_config.json

Makefile

@@ -178,3 +178,9 @@ test-smolvla-ete-eval:
 		--env.episode_length=5 \
 		--eval.n_episodes=1 \
 		--eval.batch_size=1
+
+# E2E annotation pipeline smoke test against a tiny in-memory fixture
+# dataset. Opt-in (not part of `make test-end-to-end`) and uses a stub VLM
+# backend, so it does not require a real model checkpoint or GPU.
+annotation-e2e:
+	uv run python -m tests.annotations.run_e2e_smoke

benchmarks/video/run_video_benchmark.py

@@ -39,7 +39,6 @@ from tqdm import tqdm
 
 from lerobot.datasets.lerobot_dataset import LeRobotDataset
 from lerobot.datasets.video_utils import (
-    VideoEncoderConfig,
     decode_video_frames,
     encode_video_frames,
 )
@@ -252,13 +251,10 @@ def benchmark_encoding_decoding(
             imgs_dir=imgs_dir,
             video_path=video_path,
             fps=fps,
-            camera_encoder_config=VideoEncoderConfig(
-                vcodec=encoding_cfg["vcodec"],
-                pix_fmt=encoding_cfg["pix_fmt"],
-                g=encoding_cfg.get("g"),
-                crf=encoding_cfg.get("crf"),
-                preset=encoding_cfg.get("preset"),
-            ),
+            vcodec=encoding_cfg["vcodec"],
+            pix_fmt=encoding_cfg["pix_fmt"],
+            g=encoding_cfg.get("g"),
+            crf=encoding_cfg.get("crf"),
             # fast_decode=encoding_cfg.get("fastdecode"),
             overwrite=True,
         )

docs/source/_toctree.yml

@@ -31,8 +31,10 @@
     title: Porting Large Datasets
   - local: using_dataset_tools
     title: Using the Dataset Tools
-  - local: dataset_subtask
-    title: Using Subtasks in the Dataset
+  - local: language_and_recipes
+    title: Language Columns and Recipes
+  - local: annotation_pipeline
+    title: Annotation Pipeline
   - local: streaming_video_encoding
     title: Streaming Video Encoding
   title: "Datasets"
@@ -61,8 +63,6 @@
     title: SARM
   title: "Reward Models"
 - sections:
-  - local: inference
-    title: Policy Deployment (lerobot-rollout)
   - local: async
     title: Use Async Inference
   - local: rtc

docs/source/act.mdx

@@ -90,6 +90,6 @@ lerobot-record \
   --dataset.single_task="Your task description" \
   --dataset.streaming_encoding=true \
   --dataset.encoder_threads=2 \
-  # --dataset.camera_encoder_config.vcodec=auto \
+  # --dataset.vcodec=auto \
   --policy.path=${HF_USER}/act_policy
 ```

docs/source/annotation_pipeline.mdx

@@ -0,0 +1,149 @@
+# Annotation Pipeline
+
+`lerobot-annotate` populates the two language columns introduced by the
+[Language Columns and Recipes](./language_and_recipes) page —
+`language_persistent` and `language_events` — directly into
+`data/chunk-*/file-*.parquet`. There is no flavor namespace and no sidecar
+file tree: multiple revisions of a dataset mean multiple dataset copies.
+
+## What the pipeline produces
+
+Three modules write into a per-episode staging tree, then a single writer
+rewrites the data shards in place:
+
+| Style / atom                                | Column                | Module   |
+| ------------------------------------------- | --------------------- | -------- |
+| `subtask` (Pi0.7-style "how, not what")     | `language_persistent` | Module 1 |
+| `plan` (initial + refresh on interjection)  | `language_persistent` | Module 1 |
+| `memory` (MEM-style compression)            | `language_persistent` | Module 1 |
+| `interjection`                              | `language_events`     | Module 2 |
+| speech tool-call atom (`style=null`, `say`) | `language_events`     | Module 2 |
+| `vqa` (user / assistant pair)               | `language_events`     | Module 3 |
+
+The writer also adds a dataset-level `tools` column carrying the JSON schema
+for the `say` tool call, and drops the legacy `subtask_index` column.
+
+## How to run it locally or on SLURM
+
+Install the extra and invoke the console script:
+
+```bash
+uv sync --extra annotations
+uv run lerobot-annotate \
+  --repo_id=imstevenpmwork/super_poulain_draft \
+  --vlm.backend=vllm \
+  --vlm.model_id=Qwen/Qwen3.6-27B-FP8 \
+  --vlm.tensor_parallel_size=2
+```
+
+The pipeline attaches actual camera footage to every Module 1/2/3 prompt
+by default, decoded from the dataset's first `observation.images.*`
+stream. Override with `--vlm.camera_key=observation.images.<name>` to
+pin a specific viewpoint. Datasets with no video tracks fall back to
+text-only prompts automatically.
+
+**Module 1 sees the whole episode as one video block.** Subtask
+decomposition gets a `{"type":"video", "video":[<frames>]}` block
+covering the entire demonstration; Qwen-VL pools temporally on its own
+and decides where to cut. There is no keyframe stride or count knob —
+`--module_1.max_video_frames` (default 32) only caps the frames packed
+into the video block as a model-capacity bound. Module 2 attaches a
+single still frame at the interjection timestamp; Module 3 attaches the
+exact emission frame to each VQA pair.
+
+The executor picks `LocalPipelineExecutor` for small datasets and
+`SlurmPipelineExecutor` for large ones based on
+`--executor.auto_threshold` (default 32 episodes). Force local with
+`--executor.force_local=true`. SLURM jobs honour `--executor.slurm_partition`,
+`--executor.slurm_gpus`, and `--executor.slurm_time`.
+
+## Style-to-recipe consumer mapping
+
+The pipeline produces exactly the styles consumed by
+`src/lerobot/configs/recipes/pi05_hirobot.yaml`:
+
+- `low_level_execution`, `high_level_subtask`, `memory_update` consume
+  `subtask`/`plan`/`memory` from `language_persistent`.
+- `user_interjection_response` consumes `interjection` events plus the
+  paired speech atom (merged into one assistant target turn via
+  `tool_calls_from`) and the same-timestamp `plan` refresh.
+- `ask_vqa` consumes the `(vqa, user)` and `(vqa, assistant)` pairs from
+  `language_events`.
+
+## Why the design is scoped to the canonical recipe
+
+Two things drive the scope:
+
+1. **Persistent state vs exact-event split.** Persistent rows (`subtask`,
+   `plan`, `memory`) broadcast per episode and answer "what state is in
+   force at this frame?". Event rows (`interjection`, `vqa`, speech) only
+   appear on the exact frame whose timestamp matches the emission. The
+   pipeline writes timestamps taken straight from the source parquet — no
+   floating-point recomputation.
+2. **One Qwen-VL pass.** All three modules share a single VLM client
+   (vLLM if available, transformers fallback) so the cost is one model
+   load per dataset, not three.
+
+## Module independence and staged reruns
+
+Each module writes its raw output to
+`<root>/.annotate_staging/episode_{N:06d}/<module>.jsonl`. That makes
+prompt iteration cheap — re-running one module overwrites only its own
+JSONL file before the writer composes the final parquet. Modules can be
+disabled via `--module_1.enabled=false` (and similarly for 2 and 3) to
+test them in isolation.
+
+## Validation/report checks before final write
+
+Before the writer runs, `StagingValidator` checks:
+
+- exact frame-timestamp alignment for every event row;
+- no orphan speech / interjection pairs;
+- `plan` is refreshed at every interjection timestamp;
+- `memory` rows fall on subtask boundaries (warning, not error);
+- VQA assistant `content` parses as JSON in one of the
+  bbox / keypoint / count / attribute / spatial shapes;
+- every row routes to the column dictated by `column_for_style(style)`.
+
+Errors abort the writer (`--skip_validation=true` overrides for debugging).
+
+## Paper inspirations per module
+
+- **Module 1 — subtasks.** Hi Robot ([Shi 2025](https://arxiv.org/abs/2502.19417))
+  atom granularity ("pick up one piece of lettuce", "place bowl to box");
+  Pi0.7 ([Physical Intelligence 2025](https://pi.website/pi07)) "how, not
+  what" detail.
+- **Module 1 — memory.** MEM ([Torne 2026](https://arxiv.org/abs/2603.03596))
+  compression directive: keep only minimal relevant information; functional
+  outcomes preserved, specific attributes dropped.
+- **Module 2 — interjections.** Hi Robot scenario taxonomy: negative task,
+  situated correction, specific constraint, preference. Speech is a
+  tool-call-only atom (`tool_calls=[{type:function, function:{name:"say",
+arguments:{text:...}}}]`).
+- **Module 3 — VQA.** ECoT ([Zawalski 2024](https://arxiv.org/abs/2407.08693))
+  grounded features (bounding boxes in pixel `[x_min, y_min, x_max, y_max]`,
+  keypoints) and Steerable Policies' multi-abstraction grounding.
+
+Future maintainers should adjust the prompt templates in
+`src/lerobot/annotations/steerable_pipeline/prompts/` against these
+references rather than rewriting from scratch.
+
+## Compute and list-size estimates
+
+Per episode, the pipeline issues O(`max_steps`) Module 1 calls,
+O(`max_interjections_per_episode`) Module 2 calls, and
+O(`vqa_emission_hz × episode_seconds`) Module 3 calls. With defaults
+(8 subtasks, 1 interjection, 1 Hz × 3 pairs) and 30-second episodes, that
+is ~50 VLM calls per episode. `language_persistent` per episode is ~10s of
+KB at most (parquet dictionary-encodes one entry per episode);
+`language_events` is empty on most frames and is bounded by the number of
+emissions, not `num_frames × num_emissions`.
+
+## Reproducibility via seed and prompt hashes
+
+`--seed` (default 1729) feeds the per-episode RNGs that select interjection
+timestamps and VQA question types. Combined with the deterministic prompt
+templates checked into `prompts/`, two runs at the same seed against the
+same dataset and the same model checkpoint produce byte-identical staging
+artifacts. Prompt edits are recorded by file hash; future tooling can pin
+expected `(seed, prompt_hash)` pairs into the dataset card.

docs/source/dataset_subtask.mdx

@@ -1,277 +0,0 @@
-# Using Subtasks in LeRobot Datasets
-
-Subtask support in robotics datasets has proven effective in improving robot reasoning and understanding. Subtasks are particularly useful for:
-
-- **Hierarchical policies**: Building policies that include subtask predictions to visualize robot reasoning in real time
-- **Reward modeling**: Helping reward models understand task progression (e.g., SARM-style stage-aware reward models)
-- **Task decomposition**: Breaking down complex manipulation tasks into atomic, interpretable steps
-
-LeRobotDataset now supports subtasks as part of its dataset structure, alongside tasks.
-
-## What are Subtasks?
-
-While a **task** describes the overall goal (e.g., "Pick up the apple and place it in the basket"), **subtasks** break down the execution into finer-grained steps:
-
-1. "Approach the apple"
-2. "Grasp the apple"
-3. "Lift the apple"
-4. "Move to basket"
-5. "Release the apple"
-
-Each frame in the dataset can be annotated with its corresponding subtask, enabling models to learn and predict these intermediate stages.
-
-<img
-  src="https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/lerobot/subtask-asset.png"
-  alt="An overview of subtask annotation showing how frames are labeled with intermediate subtask stages"
-  width="80%"
-/>
-
-<p>
-  <em>Figure: Overview of subtask annotation.</em>
-</p>
-
-**Reference:** _Subtask-learning based for robot self-assembly in flexible collaborative assembly in manufacturing_, Original Article, Published: 19 April 2022.
-
-## Dataset Structure
-
-Subtask information is stored in the dataset metadata:
-
-```
-my-dataset/
-├── data/
-│   └── ...
-├── meta/
-│   ├── info.json
-│   ├── stats.json
-│   ├── tasks.parquet
-│   ├── subtasks.parquet      # Subtask index → subtask string mapping
-│   └── episodes/
-│       └── ...
-└── videos/
-    └── ...
-```
-
-### Subtasks Parquet File
-
-The `meta/subtasks.parquet` file maps subtask indices to their natural language descriptions:
-
-| subtask_index | subtask (index column) |
-| ------------- | ---------------------- |
-| 0             | "Approach the apple"   |
-| 1             | "Grasp the apple"      |
-| 2             | "Lift the apple"       |
-| ...           | ...                    |
-
-### Frame-Level Annotations
-
-Each frame in the dataset can include a `subtask_index` field that references the subtasks parquet file:
-
-```python
-# Example frame data in the parquet file
-{
-    "index": 42,
-    "timestamp": 1.4,
-    "episode_index": 0,
-    "task_index": 0,
-    "subtask_index": 2,  # References "Lift the apple"
-    "observation.state": [...],
-    "action": [...],
-}
-```
-
-## Annotating Datasets with Subtasks
-
-We provide a HuggingFace Space for easily annotating any LeRobotDataset with subtasks:
-
-**[https://huggingface.co/spaces/lerobot/annotate](https://huggingface.co/spaces/lerobot/annotate)**
-
-After completing your annotation:
-
-1. Click "Push to Hub" to upload your annotated dataset
-2. You can also run the annotation space locally by following the instructions at [github.com/huggingface/lerobot-annotate](https://github.com/huggingface/lerobot-annotate)
-
-## Loading Datasets with Subtasks
-
-When you load a dataset with subtask annotations, the subtask information is automatically available:
-
-```python
-from lerobot.datasets import LeRobotDataset
-
-# Load a dataset with subtask annotations
-dataset = LeRobotDataset("jadechoghari/collect-fruit-annotated")
-
-# Access a sample
-sample = dataset[100]
-
-# The sample includes both task and subtask information
-print(sample["task"])        # "Collect the fruit"
-print(sample["subtask"])     # "Grasp the apple"
-print(sample["task_index"])  # tensor(0)
-print(sample["subtask_index"])  # tensor(2)
-```
-
-### Checking for Subtask Support
-
-You can check if a dataset has subtask annotations:
-
-```python
-# Check if subtasks are available
-has_subtasks = (
-    "subtask_index" in dataset.features
-    and dataset.meta.subtasks is not None
-)
-
-if has_subtasks:
-    print(f"Dataset has {len(dataset.meta.subtasks)} unique subtasks")
-    print("Subtasks:", list(dataset.meta.subtasks.index))
-```
-
-## Using Subtasks for Training
-
-### With the Tokenizer Processor
-
-The `TokenizerProcessor` automatically handles subtask tokenization for Vision-Language Action (VLA) models:
-
-```python
-from lerobot.processor import TokenizerProcessorStep
-
-# Create a tokenizer processor step
-tokenizer_processor = TokenizerProcessorStep(
-    tokenizer_name_or_path="google/paligemma-3b-pt-224",
-    padding="max_length",
-    max_length=64,
-)
-
-# The processor will automatically tokenize subtasks if present in the batch
-# and add them to the observation under:
-# - "observation.subtask.tokens"
-# - "observation.subtask.attention_mask"
-```
-
-When subtasks are available in the batch, the tokenizer processor adds:
-
-- `observation.subtask.tokens`: Tokenized subtask text
-- `observation.subtask.attention_mask`: Attention mask for the subtask tokens
-
-### DataLoader with Subtasks
-
-```python
-import torch
-from lerobot.datasets import LeRobotDataset
-
-dataset = LeRobotDataset("jadechoghari/collect-fruit-annotated")
-
-dataloader = torch.utils.data.DataLoader(
-    dataset,
-    batch_size=16,
-    shuffle=True,
-)
-
-for batch in dataloader:
-    # Access subtask information in the batch
-    subtasks = batch["subtask"]  # List of subtask strings
-    subtask_indices = batch["subtask_index"]  # Tensor of subtask indices
-
-    # Use for training hierarchical policies or reward models
-    print(f"Batch subtasks: {set(subtasks)}")
-```
-
-## Example Datasets with Subtask Annotations
-
-Try loading a dataset with subtask annotations:
-
-```python
-from lerobot.datasets import LeRobotDataset
-
-# Example dataset with subtask annotations
-dataset = LeRobotDataset("jadechoghari/collect-fruit-annotated")
-
-# Explore the subtasks
-print("Available subtasks:")
-for subtask_name in dataset.meta.subtasks.index:
-    print(f"  - {subtask_name}")
-
-# Get subtask distribution
-subtask_counts = {}
-for i in range(len(dataset)):
-    sample = dataset[i]
-    subtask = sample["subtask"]
-    subtask_counts[subtask] = subtask_counts.get(subtask, 0) + 1
-
-print("\nSubtask distribution:")
-for subtask, count in sorted(subtask_counts.items(), key=lambda x: -x[1]):
-    print(f"  {subtask}: {count} frames")
-```
-
-## Use Cases
-
-### 1. Hierarchical Policy Training
-
-Train policies that predict both actions and current subtask:
-
-```python
-class HierarchicalPolicy(nn.Module):
-    def __init__(self, num_subtasks):
-        super().__init__()
-        self.action_head = nn.Linear(hidden_dim, action_dim)
-        self.subtask_head = nn.Linear(hidden_dim, num_subtasks)
-
-    def forward(self, observations):
-        features = self.encoder(observations)
-        actions = self.action_head(features)
-        subtask_logits = self.subtask_head(features)
-        return actions, subtask_logits
-```
-
-### 2. Stage-Aware Reward Modeling (SARM)
-
-Build reward models that understand task progression:
-
-```python
-# SARM predicts:
-# - Stage: Which subtask is being executed (discrete)
-# - Progress: How far along the subtask (continuous 0-1)
-
-class SARMRewardModel(nn.Module):
-    def forward(self, observations):
-        features = self.encoder(observations)
-        stage_logits = self.stage_classifier(features)
-        progress = self.progress_regressor(features)
-        return stage_logits, progress
-```
-
-### 3. Progress Visualization
-
-Monitor robot execution by tracking subtask progression:
-
-```python
-def visualize_execution(model, observations):
-    for t, obs in enumerate(observations):
-        action, subtask_logits = model(obs)
-        predicted_subtask = subtask_names[subtask_logits.argmax()]
-        print(f"t={t}: Executing '{predicted_subtask}'")
-```
-
-## API Reference
-
-### LeRobotDataset Properties
-
-| Property                    | Type                   | Description                                |
-| --------------------------- | ---------------------- | ------------------------------------------ |
-| `meta.subtasks`             | `pd.DataFrame \| None` | DataFrame mapping subtask names to indices |
-| `features["subtask_index"]` | `dict`                 | Feature spec for subtask_index if present  |
-
-### Sample Keys
-
-When subtasks are available, each sample includes:
-
-| Key             | Type           | Description                          |
-| --------------- | -------------- | ------------------------------------ |
-| `subtask_index` | `torch.Tensor` | Integer index of the current subtask |
-| `subtask`       | `str`          | Natural language subtask description |
-
-## Related Resources
-
-- [SARM Paper](https://arxiv.org/pdf/2509.25358) - Stage-Aware Reward Modeling for Long Horizon Robot Manipulation
-- [LeRobot Annotate Space](https://huggingface.co/spaces/lerobot/annotate) - Interactive annotation tool
-- [LeRobotDataset v3.0](./lerobot-dataset-v3) - Dataset format documentation

docs/source/earthrover_mini_plus.mdx

@@ -194,7 +194,7 @@ lerobot-record \
     --dataset.single_task="Navigate around obstacles" \
     --dataset.streaming_encoding=true \
     --dataset.encoder_threads=2 \
-    # --dataset.camera_encoder_config.vcodec=auto \
+    # --dataset.vcodec=auto \
     --display_data=true
 ```
 

docs/source/groot.mdx

@@ -123,7 +123,7 @@ lerobot-record \
   --dataset.single_task="Grab and handover the red cube to the other arm" \
   --dataset.streaming_encoding=true \
   --dataset.encoder_threads=2 \
-  # --dataset.camera_encoder_config.vcodec=auto \
+  # --dataset.vcodec=auto \
   --policy.path=<user>/groot-bimanual \ # your trained model
   --dataset.episode_time_s=30 \
   --dataset.reset_time_s=10

docs/source/hil_data_collection.mdx

@@ -50,30 +50,30 @@ This process can be repeated iteratively: deploy, collect, fine-tune, repeat. Ea
 
 ### Teleoperator Requirements
 
-The `lerobot-rollout --strategy.type=dagger` mode requires **teleoperators with active motors** that can:
+The `examples/hil` HIL scripts require **teleoperators with active motors** that can:
 
 - Enable/disable torque programmatically
 - Move to target positions (to mirror the robot state when pausing)
 
-**Compatible teleoperators:**
+**Compatible teleoperators in the current `examples/hil` scripts:**
 
 - `openarm_mini` - OpenArm Mini
 - `so_leader` - SO100 / SO101 leader arm
 
 > [!IMPORTANT]
-> The provided commands default to `bi_openarm_follower` + `openarm_mini`.
+> The provided `examples/hil` commands default to `bi_openarm_follower` + `openarm_mini`.
 > `so_follower` + `so_leader` configs are also registered and can be used via CLI flags.
 
 ---
 
 ## Script
 
-Use `lerobot-rollout` with `--strategy.type=dagger` for HIL data collection. Select the inference backend with `--inference.type=sync|rtc`:
+A single script handles both synchronous and RTC-based inference. Toggle RTC with `--rtc.enabled=true`:
 
-| Mode                     | Flag                   | Models                |
-| ------------------------ | ---------------------- | --------------------- |
-| Standard (default)       | _(no flag needed)_     | ACT, Diffusion Policy |
-| Real-Time Chunking (RTC) | `--inference.type=rtc` | Pi0, Pi0.5, SmolVLA   |
+| Mode                     | Flag                 | Models                |
+| ------------------------ | -------------------- | --------------------- |
+| Standard (default)       | _(no flag needed)_   | ACT, Diffusion Policy |
+| Real-Time Chunking (RTC) | `--rtc.enabled=true` | Pi0, Pi0.5, SmolVLA   |
 
 ---
 
@@ -97,7 +97,7 @@ python src/lerobot/scripts/lerobot_train.py \
 **Standard inference (ACT, Diffusion Policy):**
 
 ```bash
-lerobot-rollout --strategy.type=dagger \
+python examples/hil/hil_data_collection.py \
     --robot.type=bi_openarm_follower \
     --robot.left_arm_config.port=can1 \
     --robot.left_arm_config.side=left \
@@ -108,10 +108,11 @@ lerobot-rollout --strategy.type=dagger \
     --teleop.port_left=/dev/ttyACM0 \
     --teleop.port_right=/dev/ttyACM1 \
     --policy.path=outputs/pretrain/checkpoints/last/pretrained_model \
-    --dataset.repo_id=your-username/rollout_hil_dataset \
+    --dataset.repo_id=your-username/hil-dataset \
     --dataset.single_task="Fold the T-shirt properly" \
     --dataset.fps=30 \
-    --strategy.num_episodes=50 \
+    --dataset.episode_time_s=1000 \
+    --dataset.num_episodes=50 \
     --interpolation_multiplier=2
 ```
 
@@ -120,11 +121,11 @@ lerobot-rollout --strategy.type=dagger \
 For models with high inference latency, enable RTC for smooth execution:
 
 ```bash
-lerobot-rollout --strategy.type=dagger \
-    --inference.type=rtc \
-    --inference.rtc.execution_horizon=20 \
-    --inference.rtc.max_guidance_weight=5.0 \
-    --inference.rtc.prefix_attention_schedule=LINEAR \
+python examples/hil/hil_data_collection.py \
+    --rtc.enabled=true \
+    --rtc.execution_horizon=20 \
+    --rtc.max_guidance_weight=5.0 \
+    --rtc.prefix_attention_schedule=LINEAR \
     --robot.type=bi_openarm_follower \
     --robot.left_arm_config.port=can1 \
     --robot.left_arm_config.side=left \
@@ -135,10 +136,11 @@ lerobot-rollout --strategy.type=dagger \
     --teleop.port_left=/dev/ttyACM0 \
     --teleop.port_right=/dev/ttyACM1 \
     --policy.path=outputs/pretrain/checkpoints/last/pretrained_model \
-    --dataset.repo_id=your-username/rollout_hil_rtc_dataset \
+    --dataset.repo_id=your-username/hil-rtc-dataset \
     --dataset.single_task="Fold the T-shirt properly" \
     --dataset.fps=30 \
-    --strategy.num_episodes=50 \
+    --dataset.episode_time_s=1000 \
+    --dataset.num_episodes=50 \
     --interpolation_multiplier=3
 ```
 
@@ -233,7 +235,7 @@ This HIL data collection approach builds on ideas from interactive imitation lea
 
 - **HG-DAgger** (Kelly et al., 2019) made this practical for robotics: a human expert monitors the robot and only intervenes when needed, rather than labeling every state. The gating between autonomous and human control is exactly the pause → takeover → return-to-policy loop used in the scripts here.
 
-- **RaC** (Hu et al., 2025) scales this loop to long-horizon tasks by explicitly decomposing interventions into **recovery** (teleoperating back to a good state) and **correction** (demonstrating the right behavior from there). This decomposition is the protocol followed by the DAgger strategy in `lerobot-rollout`.
+- **RaC** (Hu et al., 2025) scales this loop to long-horizon tasks by explicitly decomposing interventions into **recovery** (teleoperating back to a good state) and **correction** (demonstrating the right behavior from there). This decomposition is the protocol followed by the HIL scripts in `examples/hil`.
 
 - **π0.6/RECAP** (Physical Intelligence, 2025) applies the same iterative collect-and-finetune loop at scale with VLA models, showing that even large pretrained policies benefit substantially from targeted human corrections on their own failure modes. π0.6 is trained using RECAP.
 

docs/source/hope_jr.mdx

@@ -232,7 +232,7 @@ lerobot-record \
     --dataset.private=true \
     --dataset.streaming_encoding=true \
     --dataset.encoder_threads=2 \
-    # --dataset.camera_encoder_config.vcodec=auto \
+    # --dataset.vcodec=auto \
     --display_data=true
 ```
 
@@ -278,6 +278,6 @@ lerobot-record \
   --dataset.num_episodes=10 \
   --dataset.streaming_encoding=true \
   --dataset.encoder_threads=2 \
-  # --dataset.camera_encoder_config.vcodec=auto \
+  # --dataset.vcodec=auto \
   --policy.path=outputs/train/hopejr_hand/checkpoints/last/pretrained_model
 ```

docs/source/il_robots.mdx

@@ -193,7 +193,7 @@ lerobot-record \
     --dataset.num_episodes=5 \
     --dataset.single_task="Grab the black cube" \
     --dataset.streaming_encoding=true \
-    # --dataset.camera_encoder_config.vcodec=auto \
+    # --dataset.vcodec=auto \
     --dataset.encoder_threads=2
 ```
 </hfoption>
@@ -509,42 +509,121 @@ hf upload ${HF_USER}/act_so101_test${CKPT} \
 
 ## Run inference and evaluate your policy
 
-Use `lerobot-rollout` to deploy a trained policy on your robot. You can choose different strategies depending on your needs:
+You can use the `record` script from [`lerobot-record`](https://github.com/huggingface/lerobot/blob/main/src/lerobot/scripts/lerobot_record.py) with a policy checkpoint as input, to run inference and evaluate your policy. For instance, run this command or API example to run inference and record 10 evaluation episodes:
 
 <hfoptions id="eval">
-<hfoption id="Base mode (no recording)">
+<hfoption id="Command">
 ```bash
-lerobot-rollout \
-  --strategy.type=base \
-  --policy.path=${HF_USER}/my_policy \
-  --robot.type=so100_follower \
-  --robot.port=/dev/ttyACM1 \
-  --robot.cameras="{ up: {type: opencv, index_or_path: /dev/video10, width: 640, height: 480, fps: 30}, side: {type: intelrealsense, serial_number_or_name: 233522074606, width: 640, height: 480, fps: 30}}" \
-  --task="Put lego brick into the transparent box" \
-  --duration=60
-```
-</hfoption>
-<hfoption id="Sentry mode (with recording)">
-```bash
-lerobot-rollout \
-  --strategy.type=sentry \
-  --strategy.upload_every_n_episodes=5 \
-  --policy.path=${HF_USER}/my_policy \
+lerobot-record  \
   --robot.type=so100_follower \
   --robot.port=/dev/ttyACM1 \
   --robot.cameras="{ up: {type: opencv, index_or_path: /dev/video10, width: 640, height: 480, fps: 30}, side: {type: intelrealsense, serial_number_or_name: 233522074606, width: 640, height: 480, fps: 30}}" \
+  --robot.id=my_awesome_follower_arm \
+  --display_data=false \
   --dataset.repo_id=${HF_USER}/eval_so100 \
   --dataset.single_task="Put lego brick into the transparent box" \
-  --duration=600
+  --dataset.streaming_encoding=true \
+  --dataset.encoder_threads=2 \
+  # --dataset.vcodec=auto \
+  # <- Teleop optional if you want to teleoperate in between episodes \
+  # --teleop.type=so100_leader \
+  # --teleop.port=/dev/ttyACM0 \
+  # --teleop.id=my_awesome_leader_arm \
+  --policy.path=${HF_USER}/my_policy
 ```
+</hfoption>
+<hfoption id="API example">
+
+<!-- prettier-ignore-start -->
+```python
+from lerobot.cameras.opencv import OpenCVCameraConfig
+from lerobot.datasets import LeRobotDataset
+from lerobot.utils.feature_utils import hw_to_dataset_features
+from lerobot.policies.act import ACTPolicy
+from lerobot.policies import make_pre_post_processors
+from lerobot.robots.so_follower import SO100Follower, SO100FollowerConfig
+from lerobot.scripts.lerobot_record import record_loop
+from lerobot.common.control_utils import init_keyboard_listener
+from lerobot.utils.utils import log_say
+from lerobot.utils.visualization_utils import init_rerun
+
+
+NUM_EPISODES = 5
+FPS = 30
+EPISODE_TIME_SEC = 60
+TASK_DESCRIPTION = "My task description"
+HF_MODEL_ID = "<hf_username>/<model_repo_id>"
+HF_DATASET_ID = "<hf_username>/<eval_dataset_repo_id>"
+
+# Create the robot configuration
+camera_config = {"front": OpenCVCameraConfig(index_or_path=0, width=640, height=480, fps=FPS)}
+robot_config = SO100FollowerConfig(
+    port="/dev/tty.usbmodem58760434471", id="my_awesome_follower_arm", cameras=camera_config
+)
+
+# Initialize the robot
+robot = SO100Follower(robot_config)
+
+# Initialize the policy
+policy = ACTPolicy.from_pretrained(HF_MODEL_ID)
+
+# Configure the dataset features
+action_features = hw_to_dataset_features(robot.action_features, "action")
+obs_features = hw_to_dataset_features(robot.observation_features, "observation")
+dataset_features = {**action_features, **obs_features}
+
+# Create the dataset
+dataset = LeRobotDataset.create(
+    repo_id=HF_DATASET_ID,
+    fps=FPS,
+    features=dataset_features,
+    robot_type=robot.name,
+    use_videos=True,
+    image_writer_threads=4,
+)
+
+# Initialize the keyboard listener and rerun visualization
+_, events = init_keyboard_listener()
+init_rerun(session_name="recording")
+
+# Connect the robot
+robot.connect()
+
+preprocessor, postprocessor = make_pre_post_processors(
+    policy_cfg=policy,
+    pretrained_path=HF_MODEL_ID,
+    dataset_stats=dataset.meta.stats,
+)
+
+for episode_idx in range(NUM_EPISODES):
+    log_say(f"Running inference, recording eval episode {episode_idx + 1} of {NUM_EPISODES}")
+
+    # Run the policy inference loop
+    record_loop(
+        robot=robot,
+        events=events,
+        fps=FPS,
+        policy=policy,
+        preprocessor=preprocessor,
+        postprocessor=postprocessor,
+        dataset=dataset,
+        control_time_s=EPISODE_TIME_SEC,
+        single_task=TASK_DESCRIPTION,
+        display_data=True,
+    )
+
+    dataset.save_episode()
+
+# Clean up
+robot.disconnect()
+dataset.push_to_hub()
+```
+<!-- prettier-ignore-end -->
+
 </hfoption>
 </hfoptions>
 
-The `--strategy.type` flag selects the execution mode:
+As you can see, it's almost the same command as previously used to record your training dataset. Two things changed:
 
-- `base`: Autonomous rollout with no data recording (useful for quick evaluation)
-- `sentry`: Continuous recording with auto-upload (useful for large-scale evaluation)
-- `highlight`: Ring buffer recording with keystroke save (useful for capturing interesting events)
-- `dagger`: Human-in-the-loop data collection (see [HIL Data Collection](./hil_data_collection))
-
-All strategies support `--inference.type=rtc` for smooth execution with slow VLA models (Pi0, Pi0.5, SmolVLA).
+1. There is an additional `--control.policy.path` argument which indicates the path to your policy checkpoint with (e.g. `outputs/train/eval_act_so101_test/checkpoints/last/pretrained_model`). You can also use the model repository if you uploaded a model checkpoint to the hub (e.g. `${HF_USER}/act_so101_test`).
+2. The name of dataset begins by `eval` to reflect that you are running inference (e.g. `${HF_USER}/eval_act_so101_test`).

docs/source/inference.mdx

@@ -1,261 +0,0 @@
-# Policy Deployment (lerobot-rollout)
-
-`lerobot-rollout` is the single CLI for deploying trained policies on real robots. It supports multiple execution strategies and inference backends, from quick evaluation to continuous recording and human-in-the-loop data collection.
-
-## Quick Start
-
-No extra dependencies are needed beyond your robot and policy extras.
-
-```bash
-lerobot-rollout \
-    --strategy.type=base \
-    --policy.path=lerobot/act_koch_real \
-    --robot.type=koch_follower \
-    --robot.port=/dev/ttyACM0 \
-    --task="pick up cube" \
-    --duration=30
-```
-
-This runs the policy for 30 seconds with no recording.
-
----
-
-## Strategies
-
-Select a strategy with `--strategy.type=<name>`. Each strategy defines a different control loop with its own recording and interaction semantics.
-
-### Base (`--strategy.type=base`)
-
-Autonomous policy execution with no data recording. Use this for quick evaluation, demos, or when you only need to observe the robot.
-
-```bash
-lerobot-rollout \
-    --strategy.type=base \
-    --policy.path=${HF_USER}/my_policy \
-    --robot.type=so100_follower \
-    --robot.port=/dev/ttyACM0 \
-    --robot.cameras="{ front: {type: opencv, index_or_path: 0, width: 640, height: 480, fps: 30}}" \
-    --task="Put lego brick into the box" \
-    --duration=60
-```
-
-| Flag             | Description                                            |
-| ---------------- | ------------------------------------------------------ |
-| `--duration`     | Run time in seconds (0 = infinite)                     |
-| `--task`         | Task description passed to the policy                  |
-| `--display_data` | Stream observations/actions to Rerun for visualization |
-
-### Sentry (`--strategy.type=sentry`)
-
-Continuous autonomous recording with periodic upload to the Hugging Face Hub. Episode boundaries are auto-computed from camera resolution and FPS so each saved episode produces a complete video file, keeping uploads efficient.
-
-Policy state (hidden state, RTC queue) persists across episode boundaries: the robot does not reset between episodes.
-
-```bash
-lerobot-rollout \
-    --strategy.type=sentry \
-    --strategy.upload_every_n_episodes=5 \
-    --policy.path=${HF_USER}/my_policy \
-    --robot.type=so100_follower \
-    --robot.port=/dev/ttyACM0 \
-    --robot.cameras="{ front: {type: opencv, index_or_path: 0, width: 640, height: 480, fps: 30}}" \
-    --dataset.repo_id=${HF_USER}/rollout_eval_data \
-    --dataset.single_task="Put lego brick into the box" \
-    --duration=3600
-```
-
-| Flag                                   | Description                                                 |
-| -------------------------------------- | ----------------------------------------------------------- |
-| `--strategy.upload_every_n_episodes`   | Push to Hub every N episodes (default: 5)                   |
-| `--strategy.target_video_file_size_mb` | Target video file size for episode rotation (default: auto) |
-| `--dataset.repo_id`                    | **Required.** Hub repository for the recorded dataset       |
-| `--dataset.push_to_hub`                | Whether to push to Hub on teardown (default: true)          |
-
-### Highlight (`--strategy.type=highlight`)
-
-Autonomous rollout with on-demand recording via a memory-bounded ring buffer. The robot runs continuously while the buffer captures the last N seconds of telemetry. Press the save key to flush the buffer and start live recording; press it again to save the episode.
-
-```bash
-lerobot-rollout \
-    --strategy.type=highlight \
-    --strategy.ring_buffer_seconds=30 \
-    --strategy.save_key=s \
-    --strategy.push_key=h \
-    --policy.path=${HF_USER}/my_policy \
-    --robot.type=koch_follower \
-    --robot.port=/dev/ttyACM0 \
-    --dataset.repo_id=${HF_USER}/rollout_highlight_data \
-    --dataset.single_task="Pick up the red cube"
-```
-
-**Keyboard controls:**
-
-| Key                | Action                                                   |
-| ------------------ | -------------------------------------------------------- |
-| `s` (configurable) | Start recording (flushes buffer) / stop and save episode |
-| `h` (configurable) | Push dataset to Hub                                      |
-| `ESC`              | Stop the session                                         |
-
-| Flag                                   | Description                                    |
-| -------------------------------------- | ---------------------------------------------- |
-| `--strategy.ring_buffer_seconds`       | Duration of buffered telemetry (default: 30)   |
-| `--strategy.ring_buffer_max_memory_mb` | Memory cap for the ring buffer (default: 2048) |
-| `--strategy.save_key`                  | Key to toggle recording (default: `s`)         |
-| `--strategy.push_key`                  | Key to push to Hub (default: `h`)              |
-
-### DAgger (`--strategy.type=dagger`)
-
-Human-in-the-loop data collection. Alternates between autonomous policy execution and human intervention via a teleoperator. Intervention frames are tagged with `intervention=True`. Requires a teleoperator (`--teleop.type`).
-
-See the [Human-In-the-Loop Data Collection](./hil_data_collection) guide for a detailed walkthrough.
-
-**Corrections-only mode** (default): Only human correction windows are recorded. Each correction becomes one episode.
-
-```bash
-lerobot-rollout \
-    --strategy.type=dagger \
-    --strategy.num_episodes=20 \
-    --policy.path=outputs/pretrain/checkpoints/last/pretrained_model \
-    --robot.type=bi_openarm_follower \
-    --teleop.type=openarm_mini \
-    --dataset.repo_id=${HF_USER}/rollout_hil_data \
-    --dataset.single_task="Fold the T-shirt"
-```
-
-**Continuous recording mode** (`--strategy.record_autonomous=true`): Both autonomous and correction frames are recorded with time-based episode rotation (same as Sentry).
-
-```bash
-lerobot-rollout \
-    --strategy.type=dagger \
-    --strategy.record_autonomous=true \
-    --strategy.num_episodes=50 \
-    --policy.path=${HF_USER}/my_policy \
-    --robot.type=so100_follower \
-    --robot.port=/dev/ttyACM0 \
-    --teleop.type=so101_leader \
-    --teleop.port=/dev/ttyACM1 \
-    --dataset.repo_id=${HF_USER}/rollout_dagger_data \
-    --dataset.single_task="Grasp the block"
-```
-
-**Keyboard controls** (default input device):
-
-| Key     | Action                                      |
-| ------- | ------------------------------------------- |
-| `Space` | Pause / resume policy execution             |
-| `Tab`   | Start / stop human correction               |
-| `Enter` | Push dataset to Hub (corrections-only mode) |
-| `ESC`   | Stop the session                            |
-
-Foot pedal input is also supported via `--strategy.input_device=pedal`. Configure pedal codes with `--strategy.pedal.*` flags.
-
-| Flag                                 | Description                                             |
-| ------------------------------------ | ------------------------------------------------------- |
-| `--strategy.num_episodes`            | Number of correction episodes to record (default: 10)   |
-| `--strategy.record_autonomous`       | Record autonomous frames too (default: false)           |
-| `--strategy.upload_every_n_episodes` | Push to Hub every N episodes (default: 5)               |
-| `--strategy.input_device`            | Input device: `keyboard` or `pedal` (default: keyboard) |
-| `--teleop.type`                      | **Required.** Teleoperator type                         |
-
----
-
-## Inference Backends
-
-Select a backend with `--inference.type=<name>`. All strategies work with both backends.
-
-### Sync (default)
-
-One policy call per control tick. The main loop blocks until the action is computed.
-
-Works with all policies. No extra flags needed.
-
-### Real-Time Chunking (`--inference.type=rtc`)
-
-A background thread produces action chunks asynchronously. The main control loop polls for the next ready action while the policy computes the next chunk in parallel.
-
-Use RTC with large, slow VLA models (Pi0, Pi0.5, SmolVLA) for smooth, continuous motion despite high inference latency.
-
-```bash
-lerobot-rollout \
-    --strategy.type=base \
-    --inference.type=rtc \
-    --inference.rtc.execution_horizon=10 \
-    --inference.rtc.max_guidance_weight=10.0 \
-    --policy.path=${HF_USER}/pi0_policy \
-    --robot.type=so100_follower \
-    --robot.port=/dev/ttyACM0 \
-    --robot.cameras="{ front: {type: opencv, index_or_path: 0, width: 640, height: 480, fps: 30}}" \
-    --task="Pick up the cube" \
-    --duration=60 \
-    --device=cuda
-```
-
-| Flag                                        | Description                                                    |
-| ------------------------------------------- | -------------------------------------------------------------- |
-| `--inference.rtc.execution_horizon`         | Steps to blend with previous chunk (default: varies by policy) |
-| `--inference.rtc.max_guidance_weight`       | Consistency enforcement strength (default: varies by policy)   |
-| `--inference.rtc.prefix_attention_schedule` | Blend schedule: `LINEAR`, `EXP`, `ONES`, `ZEROS`               |
-| `--inference.queue_threshold`               | Max queue size before backpressure (default: 30)               |
-
-See the [Real-Time Chunking](./rtc) guide for details on tuning RTC parameters.
-
----
-
-## Common Flags
-
-| Flag                              | Description                                                       | Default |
-| --------------------------------- | ----------------------------------------------------------------- | ------- |
-| `--policy.path`                   | **Required.** HF Hub model ID or local checkpoint path            | --      |
-| `--robot.type`                    | **Required.** Robot type (e.g. `so100_follower`, `koch_follower`) | --      |
-| `--robot.port`                    | Serial port for the robot                                         | --      |
-| `--robot.cameras`                 | Camera configuration (JSON dict)                                  | --      |
-| `--fps`                           | Control loop frequency                                            | 30      |
-| `--duration`                      | Run time in seconds (0 = infinite)                                | 0       |
-| `--device`                        | Torch device (`cpu`, `cuda`, `mps`)                               | auto    |
-| `--task`                          | Task description (used when no dataset is provided)               | --      |
-| `--display_data`                  | Stream telemetry to Rerun visualization                           | false   |
-| `--display_ip` / `--display_port` | Remote Rerun server address                                       | --      |
-| `--interpolation_multiplier`      | Action interpolation factor                                       | 1       |
-| `--use_torch_compile`             | Enable `torch.compile` for inference                              | false   |
-| `--resume`                        | Resume a previous recording session                               | false   |
-| `--play_sounds`                   | Vocal synthesis for events                                        | true    |
-
----
-
-## Programmatic Usage
-
-For custom deployments (e.g. with kinematics processors), use the rollout module API directly:
-
-```python
-from lerobot.rollout import BaseStrategyConfig, RolloutConfig, build_rollout_context
-from lerobot.rollout.inference import SyncInferenceConfig
-from lerobot.rollout.strategies import BaseStrategy
-from lerobot.utils.process import ProcessSignalHandler
-
-cfg = RolloutConfig(
-    robot=my_robot_config,
-    policy=my_policy_config,
-    strategy=BaseStrategyConfig(),
-    inference=SyncInferenceConfig(),
-    fps=30,
-    duration=60,
-    task="my task",
-)
-
-signal_handler = ProcessSignalHandler(use_threads=True)
-ctx = build_rollout_context(
-    cfg,
-    signal_handler.shutdown_event,
-    robot_action_processor=my_custom_action_processor,       # optional
-    robot_observation_processor=my_custom_obs_processor,     # optional
-)
-
-strategy = BaseStrategy(cfg.strategy)
-try:
-    strategy.setup(ctx)
-    strategy.run(ctx)
-finally:
-    strategy.teardown(ctx)
-```
-
-See `examples/so100_to_so100_EE/rollout.py` and `examples/phone_to_so100/rollout.py` for full examples with kinematics processors.

docs/source/language_and_recipes.mdx

@@ -0,0 +1,75 @@
+# Language columns and recipes
+
+LeRobot stores reusable language annotations directly next to frame data in `data/chunk-*/file-*.parquet`.
+The two optional columns are:
+
+- `language_persistent`: a list of rows broadcast across every frame in an episode for state that remains active, such as `subtask`, `plan`, and `memory`.
+- `language_events`: a list of rows only on the exact frame where an event was emitted, such as `interjection`, `vqa`, and speech tool calls.
+
+Both columns share the same row shape:
+
+```text
+role: string
+content: string | null
+style: string | null
+timestamp: float64
+tool_calls: list[Json] | null
+```
+
+`meta/tasks.parquet` remains the canonical source for the task. The special `${task}` recipe binding always reads that task string and does not depend on language annotations.
+
+## Architecture
+
+The language stack has three layers:
+
+1. `lerobot.datasets.language` defines the schema, style registry, and `column_for_style`.
+2. `lerobot.datasets.language_render` resolves rows and renders messages.
+3. `RenderMessagesStep` turns dataset samples into `messages`, `message_streams`, and `target_message_indices`.
+
+`LeRobotDataset` stays recipe-agnostic. It passes `language_persistent` and `language_events` through when present, and unannotated datasets keep their existing behavior.
+
+## Temporal semantics
+
+Persistent styles are active after emission until replaced:
+
+- `active_at(t, style=subtask)`
+- `nth_prev(style=memory, offset=1)`
+- `nth_next(style=subtask, offset=1)`
+
+Event styles only exist on their exact timestamp:
+
+- `emitted_at(t, style=interjection)`
+- `emitted_at(t, style=vqa, role=user)`
+- `emitted_at(t, role=assistant, tool_name=say)`
+
+Exact event matching has no tolerance window, so writers must stamp event rows with frame timestamps from the parquet data.
+
+## Recipe anatomy
+
+Recipes are YAML files backed by `TrainingRecipe` and `MessageTurn`.
+
+```yaml
+messages:
+  - { role: user, content: "${task}", stream: high_level }
+  - { role: assistant, content: "${subtask}", stream: low_level, target: true }
+```
+
+Rendered samples use HF-style chat messages plus LeRobot sidecars:
+
+```python
+sample["messages"]
+sample["message_streams"]
+sample["target_message_indices"]
+```
+
+The renderer does not apply a tokenizer chat template. Policy processors decide how to serialize the messages for their backbone.
+
+## Blends
+
+Blend recipes select one weighted sub-recipe deterministically from the sample index.
+The canonical `recipes/pi05_hirobot.yaml` combines memory updates, interjection responses, high-level subtask prediction, low-level execution, and VQA.
+
+## Graceful absence
+
+If both language columns are missing, `None`, or empty, `RenderMessagesStep` is a no-op.
+If an event-scoped branch is selected on a frame without the required event row, rendering returns `None`, allowing a loader to retry another sample.

docs/source/lerobot-dataset-v3.mdx

@@ -43,7 +43,7 @@ lerobot-record \
   --dataset.num_episodes=5 \
   --dataset.single_task="Grab the black cube" \
   --dataset.streaming_encoding=true \
-  # --dataset.camera_encoder_config.vcodec=auto \
+  # --dataset.vcodec=auto \
   --dataset.encoder_threads=2
 ```
 

docs/source/reachy2.mdx

@@ -161,7 +161,7 @@ lerobot-record \
     --dataset.private=true \
     --dataset.streaming_encoding=true \
     --dataset.encoder_threads=2 \
-    # --dataset.camera_encoder_config.vcodec=auto \
+    # --dataset.vcodec=auto \
     --display_data=true
 ```
 
@@ -203,7 +203,7 @@ lerobot-record \
     --dataset.private=true \
     --dataset.streaming_encoding=true \
     --dataset.encoder_threads=2 \
-    # --dataset.camera_encoder_config.vcodec=auto \
+    # --dataset.vcodec=auto \
     --display_data=true
 ```
 

docs/source/rename_map.mdx

@@ -61,6 +61,17 @@ lerobot-eval \
   --rename_map='{"observation.images.image": "observation.images.base_0_rgb", "observation.images.image2": "observation.images.left_wrist_0_rgb"}'
 ```
 
+### Recording
+
+`lerobot-record` also supports rename maps, nested under the dataset config:
+
+```bash
+lerobot-record \ # When running inference
+  --policy.path="<user>/smolVLA_finetuned" \
+  ... \
+  --dataset.rename_map='{"observation.images.glove2": "observation.images.image"}'
+```
+
 ## Alternative: edit the policy config directly
 
 If you always use the same dataset or environment, you can **edit the policy's `config.json`** so its observation keys match your data source. Then no rename map is needed.
@@ -94,10 +105,10 @@ XVLA-base has three visual inputs and `empty_cameras=0` by default. Your dataset
 
 ## Quick reference
 
-| Goal                                    | What to do                                                                  |
-| --------------------------------------- | --------------------------------------------------------------------------- |
-| Dataset keys ≠ policy keys              | `--rename_map='{"dataset_key": "policy_key", ...}'`                         |
-| Env keys ≠ policy keys (eval)           | `--rename_map='{"env_key": "policy_key", ...}'`                             |
-| Rollout with different keys (inference) | `--rename_map='{"source_key": "policy_key", ...}'`.                         |
-| Fewer cameras than policy expects       | `--policy.empty_cameras=N` (supported by PI0, PI05, PI0Fast, SmolVLA, XVLA) |
-| Avoid passing a rename map              | Edit the policy's `config.json` so its keys match your data source          |
+| Goal                                      | What to do                                                                  |
+| ----------------------------------------- | --------------------------------------------------------------------------- |
+| Dataset keys ≠ policy keys                | `--rename_map='{"dataset_key": "policy_key", ...}'`                         |
+| Env keys ≠ policy keys (eval)             | `--rename_map='{"env_key": "policy_key", ...}'`                             |
+| Recording with different keys (inference) | `--dataset.rename_map='{"source_key": "policy_key", ...}'`.                 |
+| Fewer cameras than policy expects         | `--policy.empty_cameras=N` (supported by PI0, PI05, PI0Fast, SmolVLA, XVLA) |
+| Avoid passing a rename map                | Edit the policy's `config.json` so its keys match your data source          |

docs/source/rtc.mdx

@@ -34,7 +34,7 @@ pip install -e ".[smolvla]"
 
 ### Using RTC with Pi0
 
-You can use `lerobot-rollout --strategy.type=base --inference.type=rtc` for RTC deployment on real robots.
+You can find a complete reference implementation in [eval_with_real_robot.py](examples/rtc/eval_with_real_robot.py).
 The snippet below provides a simplified pseudo-example of how RTC operates with Pi0 in your pipeline:
 
 ```python
@@ -137,12 +137,8 @@ The script generates a visualization of the denoising process, comparing standar
 ## Testing RTC with a Real Robot
 
 ```bash
-lerobot-rollout \
-    --strategy.type=base \
+python examples/rtc/eval_with_real_robot.py \
     --policy.path=${HF_USERNAME}/policy_repo_id \
-    --inference.type=rtc \
-    --inference.rtc.execution_horizon=10 \
-    --inference.rtc.max_guidance_weight=10.0 \
     --robot.type=so100_follower \
     --robot.port=/dev/tty.usbmodem58FA0834591 \
     --robot.cameras="{ gripper: {type: opencv, index_or_path: 1, width: 640, height: 480, fps: 30}, front: {type: opencv, index_or_path: 0, width: 640, height: 480, fps: 30}}" \
@@ -182,7 +178,7 @@ visualizer = RTCDebugVisualizer()
 # ... create plots
 ```
 
-See `examples/rtc/eval_dataset.py` for a complete example of offline RTC visualization.
+See `examples/rtc/eval_dataset.py` for a complete example of visualization.
 
 ## References
 

docs/source/sarm.mdx

@@ -46,7 +46,7 @@ This ensures identical task states map to consistent progress values, even acros
 
 ## Inputs and Targets (What the new code expects)
 
-SARM is trained through its processor (`src/lerobot/rewards/sarm/processor_sarm.py`), which:
+SARM is trained through its processor (`src/lerobot/policies/sarm/processor_sarm.py`), which:
 
 - **Encodes** images and task text with CLIP (ViT-B/32) into `video_features` and `text_features`
 - **Pads/truncates** robot state into `state_features` (up to `max_state_dim`)
@@ -347,7 +347,7 @@ Use `compute_rabc_weights.py` with `--visualize-only` to visualize model predict
 <hfoption id="single_stage">
 
 ```bash
-python -m lerobot.rewards.sarm.compute_rabc_weights \
+python src/lerobot/policies/sarm/compute_rabc_weights.py \
   --dataset-repo-id your-username/your-dataset \
   --reward-model-path your-username/sarm-model \
   --visualize-only \
@@ -360,7 +360,7 @@ python -m lerobot.rewards.sarm.compute_rabc_weights \
 <hfoption id="dense_only">
 
 ```bash
-python -m lerobot.rewards.sarm.compute_rabc_weights \
+python src/lerobot/policies/sarm/compute_rabc_weights.py \
   --dataset-repo-id your-username/your-dataset \
   --reward-model-path your-username/sarm-model \
   --visualize-only \
@@ -373,7 +373,7 @@ python -m lerobot.rewards.sarm.compute_rabc_weights \
 <hfoption id="dual">
 
 ```bash
-python -m lerobot.rewards.sarm.compute_rabc_weights \
+python src/lerobot/policies/sarm/compute_rabc_weights.py \
   --dataset-repo-id your-username/your-dataset \
   --reward-model-path your-username/sarm-model \
   --visualize-only \
@@ -429,7 +429,7 @@ The weighting follows **Equations 8-9** from the paper:
 First, run the SARM model on all frames in your dataset to compute progress values:
 
 ```bash
-python -m lerobot.rewards.sarm.compute_rabc_weights \
+python src/lerobot/policies/sarm/compute_rabc_weights.py \
   --dataset-repo-id your-username/your-dataset \
   --reward-model-path your-username/sarm-model \
   --head-mode sparse \
@@ -465,15 +465,15 @@ This script:
 
 ### Step 5b: Train Policy with RA-BC
 
-Once you have the progress file, train your policy with RA-BC weighting. The progress file is auto-detected from the dataset path (`sarm_progress.parquet`) if not explicitly provided. Currently PI0, PI0.5 and SmolVLA are supported with RA-BC:
+Once you have the progress file, train your policy with RA-BC weighting. The progress file is auto-detected from the dataset path (`sarm_progress.parquet`). Currently PI0, PI0.5 and SmolVLA are supported with RA-BC:
 
 ```bash
 lerobot-train \
   --dataset.repo_id=your-username/your-dataset \
   --policy.type=pi0 \
-  --sample_weighting.type=rabc \
-  --sample_weighting.head_mode=sparse \
-  --sample_weighting.kappa=0.01 \
+  --use_rabc=true \
+  --rabc_head_mode=sparse \
+  --rabc_kappa=0.01 \
   --output_dir=outputs/train/policy_rabc \
   --batch_size=32 \
   --steps=40000
@@ -488,13 +488,12 @@ The training script automatically:
 
 **RA-BC Arguments:**
 
-| Argument                           | Description                                            | Default                 |
-| ---------------------------------- | ------------------------------------------------------ | ----------------------- |
-| `--sample_weighting.type`          | Weighting strategy type (`rabc` or `uniform`)          | `rabc`                  |
-| `--sample_weighting.progress_path` | Path to progress parquet file                          | `sarm_progress.parquet` |
-| `--sample_weighting.head_mode`     | Which SARM head's progress to use: `sparse` or `dense` | `sparse`                |
-| `--sample_weighting.kappa`         | Threshold κ for high-quality samples                   | `0.01`                  |
-| `--sample_weighting.epsilon`       | Small constant for numerical stability                 | `1e-6`                  |
+| Argument               | Description                                                | Default                            |
+| ---------------------- | ---------------------------------------------------------- | ---------------------------------- |
+| `--use_rabc`           | Enable RA-BC sample weighting                              | `false`                            |
+| `--rabc_progress_path` | Path to progress parquet file (auto-detected from dataset) | `sarm_progress.parquet` in dataset |
+| `--rabc_head_mode`     | Which SARM head's progress to use: `sparse` or `dense`     | `sparse`                           |
+| `--rabc_kappa`         | Threshold κ for high-quality samples                       | `0.01`                             |
 
 ### Tuning RA-BC Kappa
 
@@ -512,30 +511,30 @@ The `kappa` parameter is the threshold that determines which samples get full we
 
 Monitor these WandB metrics during training:
 
-| Metric                        | Healthy Range | Problem Indicator         |
-| ----------------------------- | ------------- | ------------------------- |
-| `sample_weight_mean_weight`   | 0.3 - 0.8     | ≈ 1.0 means kappa too low |
-| `sample_weighting/delta_mean` | > 0           | Should be positive        |
-| `sample_weighting/delta_std`  | > 0           | Variance in data quality  |
+| Metric             | Healthy Range | Problem Indicator         |
+| ------------------ | ------------- | ------------------------- |
+| `rabc_mean_weight` | 0.3 - 0.8     | ≈ 1.0 means kappa too low |
+| `rabc_delta_mean`  | > 0           | Should be positive        |
+| `rabc_delta_std`   | > 0           | Variance in data quality  |
 
-**If `sample_weight_mean_weight ≈ 1.0`:** Your kappa is too low. Most samples have `delta > kappa` and bypass the soft-weighting entirely. RA-BC becomes equivalent to vanilla BC.
+**If `rabc_mean_weight ≈ 1.0`:** Your kappa is too low. Most samples have `delta > kappa` and bypass the soft-weighting entirely. RA-BC becomes equivalent to vanilla BC.
 
 **Setting kappa based on your data:**
 
-The default `kappa=0.01` was tuned for the paper's T-shirt folding task (~90s episodes at 30fps). For your dataset, check the logged `sample_weighting/delta_mean` and `sample_weighting/delta_std`:
+The default `kappa=0.01` was tuned for the paper's T-shirt folding task (~90s episodes at 30fps). For your dataset, check the logged `rabc_delta_mean` and `rabc_delta_std`:
 
 ```
 # If delta_mean ≈ 0.03 and delta_std ≈ 0.02:
 # Most deltas fall in range [0.01, 0.05]
 
 # Option 1: Set kappa = delta_mean (medium selectivity)
---sample_weighting.kappa=0.03
+--rabc_kappa=0.03
 
 # Option 2: Set kappa = delta_mean + delta_std (high selectivity)
---sample_weighting.kappa=0.05
+--rabc_kappa=0.05
 
 # Option 3: Set kappa = delta_mean + 2*delta_std (very selective)
---sample_weighting.kappa=0.07
+--rabc_kappa=0.07
 ```
 
 **When RA-BC may not help:**
@@ -551,8 +550,8 @@ accelerate launch \
   src/lerobot/scripts/lerobot_train.py \
   --dataset.repo_id=your-username/your-dataset \
   --policy.type=pi0 \
-  --sample_weighting.type=rabc \
-  --sample_weighting.kappa=0.01 \
+  --use_rabc=true \
+  --rabc_kappa=0.01 \
   --output_dir=outputs/train/policy_rabc \
   --batch_size=32 \
   --steps=40000
@@ -577,7 +576,7 @@ accelerate launch \
 ### RA-BC
 
 1. **Train SARM first**: RA-BC quality depends entirely on SARM quality
-2. **Monitor `sample_weight_mean_weight`**: If it's ≈ 1.0, increase kappa (see [Tuning RA-BC Kappa](#tuning-ra-bc-kappa))
+2. **Monitor `rabc_mean_weight`**: If it's ≈ 1.0, increase kappa (see [Tuning RA-BC Kappa](#tuning-ra-bc-kappa))
 
 ---
 

docs/source/smolvla.mdx

@@ -108,7 +108,7 @@ lerobot-record \
   --dataset.num_episodes=10 \
   --dataset.streaming_encoding=true \
   --dataset.encoder_threads=2 \
-  # --dataset.camera_encoder_config.vcodec=auto \
+  # --dataset.vcodec=auto \
   # <- Teleop optional if you want to teleoperate in between episodes \
   # --teleop.type=so100_leader \
   # --teleop.port=/dev/ttyACM0 \

docs/source/streaming_video_encoding.mdx

@@ -14,22 +14,12 @@ This makes `save_episode()` near-instant (the video is already encoded by the ti
 
 ## 2. Tuning Parameters
 
-All encoding parameters are grouped under `camera_encoder_config` (a `VideoEncoderConfig` dataclass), accessible from the CLI via `--dataset.camera_encoder_config.<field>`.
-
-| Parameter               | CLI Flag                                      | Type          | Default       | Description                                                         |
-| ----------------------- | --------------------------------------------- | ------------- | ------------- | ------------------------------------------------------------------- |
-| `streaming_encoding`    | `--dataset.streaming_encoding`                | `bool`        | `True`        | Enable real-time encoding during capture                            |
-| `vcodec`                | `--dataset.camera_encoder_config.vcodec`      | `str`         | `"libsvtav1"` | Video codec. `"auto"` detects best HW encoder                       |
-| `pix_fmt`               | `--dataset.camera_encoder_config.pix_fmt`     | `str`         | `"yuv420p"`   | Pixel format                                                        |
-| `g`                     | `--dataset.camera_encoder_config.g`           | `int \| None` | `2`           | GOP size (keyframe interval)                                        |
-| `crf`                   | `--dataset.camera_encoder_config.crf`         | `int \| None` | `30`          | Quality level (mapped to codec-specific parameter)                  |
-| `preset`                | `--dataset.camera_encoder_config.preset`      | `int \| None` | `12`          | Speed preset (libsvtav1 only, 0 = slowest … 13 = fastest)           |
-| `fast_decode`           | `--dataset.camera_encoder_config.fast_decode` | `int`         | `0`           | Fast-decode tuning level                                            |
-| `encoder_threads`       | `--dataset.encoder_threads`                   | `int \| None` | `None` (auto) | Threads per encoder instance (global). `None` lets the codec decide |
-| `encoder_queue_maxsize` | `--dataset.encoder_queue_maxsize`             | `int`         | `60`          | Max buffered frames per camera (~2s at 30fps). Consumes RAM         |
-
-> [!TIP]
-> Not all parameters apply to every codec. `VideoEncoderConfig` will warn at startup if you set a parameter that your chosen codec ignores (e.g. `preset` with `h264_nvenc`).
+| Parameter               | CLI Flag                          | Type          | Default       | Description                                                       |
+| ----------------------- | --------------------------------- | ------------- | ------------- | ----------------------------------------------------------------- |
+| `streaming_encoding`    | `--dataset.streaming_encoding`    | `bool`        | `True`        | Enable real-time encoding during capture                          |
+| `vcodec`                | `--dataset.vcodec`                | `str`         | `"libsvtav1"` | Video codec. `"auto"` detects best HW encoder                     |
+| `encoder_threads`       | `--dataset.encoder_threads`       | `int \| None` | `None` (auto) | Threads per encoder instance. `None` will leave the vcoded decide |
+| `encoder_queue_maxsize` | `--dataset.encoder_queue_maxsize` | `int`         | `60`          | Max buffered frames per camera (~2s at 30fps). Consumes RAM       |
 
 ## 3. Performance Considerations
 
@@ -50,7 +40,7 @@ Streaming encoding means the CPU is encoding video **during** the capture loop,
 
 ### `encoder_threads` Tuning
 
-This parameter (`--dataset.encoder_threads`) controls how many threads each encoder instance uses internally:
+This parameter controls how many threads each encoder instance uses internally:
 
 - **Higher values** (e.g., 4-5): Faster encoding, but uses more CPU cores per camera. Good for high-end systems with many cores.
 - **Lower values** (e.g., 1-2): Less CPU per camera, freeing cores for capture and visualization. Good for low-res images and capable CPUs.
@@ -92,15 +82,15 @@ Use HW encoding when:
 
 ### Available HW Encoders
 
-| Encoder             | Platform      | Hardware                                                                                         | CLI Value                                                  |
-| ------------------- | ------------- | ------------------------------------------------------------------------------------------------ | ---------------------------------------------------------- |
-| `h264_videotoolbox` | macOS         | Apple Silicon / Intel                                                                            | `--dataset.camera_encoder_config.vcodec=h264_videotoolbox` |
-| `hevc_videotoolbox` | macOS         | Apple Silicon / Intel                                                                            | `--dataset.camera_encoder_config.vcodec=hevc_videotoolbox` |
-| `h264_nvenc`        | Linux/Windows | NVIDIA GPU                                                                                       | `--dataset.camera_encoder_config.vcodec=h264_nvenc`        |
-| `hevc_nvenc`        | Linux/Windows | NVIDIA GPU                                                                                       | `--dataset.camera_encoder_config.vcodec=hevc_nvenc`        |
-| `h264_vaapi`        | Linux         | Intel/AMD GPU                                                                                    | `--dataset.camera_encoder_config.vcodec=h264_vaapi`        |
-| `h264_qsv`          | Linux/Windows | Intel Quick Sync                                                                                 | `--dataset.camera_encoder_config.vcodec=h264_qsv`          |
-| `auto`              | Any           | Probes the system for available HW encoders. Falls back to `libsvtav1` if no HW encoder is found | `--dataset.camera_encoder_config.vcodec=auto`              |
+| Encoder             | Platform      | Hardware                                                                                         | CLI Value                            |
+| ------------------- | ------------- | ------------------------------------------------------------------------------------------------ | ------------------------------------ |
+| `h264_videotoolbox` | macOS         | Apple Silicon / Intel                                                                            | `--dataset.vcodec=h264_videotoolbox` |
+| `hevc_videotoolbox` | macOS         | Apple Silicon / Intel                                                                            | `--dataset.vcodec=hevc_videotoolbox` |
+| `h264_nvenc`        | Linux/Windows | NVIDIA GPU                                                                                       | `--dataset.vcodec=h264_nvenc`        |
+| `hevc_nvenc`        | Linux/Windows | NVIDIA GPU                                                                                       | `--dataset.vcodec=hevc_nvenc`        |
+| `h264_vaapi`        | Linux         | Intel/AMD GPU                                                                                    | `--dataset.vcodec=h264_vaapi`        |
+| `h264_qsv`          | Linux/Windows | Intel Quick Sync                                                                                 | `--dataset.vcodec=h264_qsv`          |
+| `auto`              | Any           | Probes the system for available HW encoders. Falls back to `libsvtav1` if no HW encoder is found | `--dataset.vcodec=auto`              |
 
 > [!NOTE]
 > In order to use the HW accelerated encoders you might need to upgrade your GPU drivers.
@@ -110,15 +100,15 @@ Use HW encoding when:
 
 ## 5. Troubleshooting
 
-| Symptom                                                            | Likely Cause                                 | Fix                                                                                                                                                                                                                                                                                                        |
-| ------------------------------------------------------------------ | -------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| System freezes or choppy robot movement or Rerun visualization lag | CPU starved (100% load usage)                | Close other apps, reduce encoding throughput, lower `encoder_threads`, use `h264`, use `display_data=False`. If the CPU continues to be at 100% then it might be insufficient for your setup, consider `--dataset.streaming_encoding=false` or HW encoding (`--dataset.camera_encoder_config.vcodec=auto`) |
-| "Encoder queue full" warnings or dropped frames in dataset         | Encoder can't keep up (Queue overflow)       | If CPU is not at 100%: Increase `encoder_threads`, increase `encoder_queue_maxsize` or use HW encoding (`--dataset.camera_encoder_config.vcodec=auto`).                                                                                                                                                    |
-| High RAM usage                                                     | Queue filling faster than encoding           | `encoder_threads` too low or CPU insufficient. Reduce `encoder_queue_maxsize` or use HW encoding                                                                                                                                                                                                           |
-| Large video files                                                  | Using HW encoder or H.264                    | Expected trade-off. Switch to `libsvtav1` if CPU allows                                                                                                                                                                                                                                                    |
-| `save_episode()` still slow                                        | `streaming_encoding` is `False`              | Set `--dataset.streaming_encoding=true`                                                                                                                                                                                                                                                                    |
-| Encoder thread crash                                               | Codec not available or invalid settings      | Check `vcodec` is installed, try `--dataset.camera_encoder_config.vcodec=auto`                                                                                                                                                                                                                             |
-| Recorded dataset is missing frames                                 | CPU/GPU starvation or occasional load spikes | If ~5% of frames are missing, your system is likely overloaded — follow the recommendations above. If fewer frames are missing (~2%), they are probably due to occasional transient load spikes (often at startup) and can be considered expected.                                                         |
+| Symptom                                                            | Likely Cause                                 | Fix                                                                                                                                                                                                                                                                                  |
+| ------------------------------------------------------------------ | -------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
+| System freezes or choppy robot movement or Rerun visualization lag | CPU starved (100% load usage)                | Close other apps, reduce encoding throughput, lower `encoder_threads`, use `h264`, use `display_data=False`. If the CPU continues to be at 100% then it might be insufficient for your setup, consider `--dataset.streaming_encoding=false` or HW encoding (`--dataset.vcodec=auto`) |
+| "Encoder queue full" warnings or dropped frames in dataset         | Encoder can't keep up (Queue overflow)       | If CPU is not at 100%: Increase `encoder_threads`, increase `encoder_queue_maxsize` or use HW encoding (`--dataset.vcodec=auto`).                                                                                                                                                    |
+| High RAM usage                                                     | Queue filling faster than encoding           | `encoder_threads` too low or CPU insufficient. Reduce `encoder_queue_maxsize` or use HW encoding                                                                                                                                                                                     |
+| Large video files                                                  | Using HW encoder or H.264                    | Expected trade-off. Switch to `libsvtav1` if CPU allows                                                                                                                                                                                                                              |
+| `save_episode()` still slow                                        | `streaming_encoding` is `False`              | Set `--dataset.streaming_encoding=true`                                                                                                                                                                                                                                              |
+| Encoder thread crash                                               | Codec not available or invalid settings      | Check `vcodec` is installed, try `--dataset.vcodec=auto`                                                                                                                                                                                                                             |
+| Recorded dataset is missing frames                                 | CPU/GPU starvation or occasional load spikes | If ~5% of frames are missing, your system is likely overloaded — follow the recommendations above. If fewer frames are missing (~2%), they are probably due to occasional transient load spikes (often at startup) and can be considered expected.                                   |
 
 ## 6. Recommended Configurations
 
@@ -156,10 +146,10 @@ On very constrained systems, streaming encoding may compete too heavily with the
 # 2camsx 640x480x3 @30fps: Requires some tuning.
 
 # Use H.264, disable streaming, consider batching encoding
-lerobot-record --dataset.camera_encoder_config.vcodec=h264 --dataset.streaming_encoding=false ...
+lerobot-record --dataset.vcodec=h264 --dataset.streaming_encoding=false ...
 ```
 
 ## 7. Closing note
 
 Performance ultimately depends on your exact setup — frames-per-second, resolution, CPU cores and load, available memory, episode length, and the encoder you choose. Always test with your target workload, be mindful about your CPU & system capabilities and tune `encoder_threads`, `encoder_queue_maxsize`, and
-`camera_encoder_config.vcodec` reasonably. That said, a common practical configuration (for many applications) is three cameras at 640×480x3 @30fps; this usually runs fine with the default streaming video encoding settings in modern systems. Always verify your recorded dataset is healthy by comparing the video duration to the CLI episode duration and confirming the row count equals FPS × CLI duration.
+`vcodec` reasonably. That said, a common practical configuration (for many applications) is three cameras at 640×480x3 @30fps; this usually runs fine with the default streaming video encoding settings in modern systems. Always verify your recorded dataset is healthy by comparing the video duration to the CLI episode duration and confirming the row count equals FPS × CLI duration.

docs/source/unitree_g1.mdx

@@ -274,8 +274,7 @@ python src/lerobot/scripts/lerobot_train.py \
 Once trained, we recommend deploying policies using inference-time RTC:
 
 ```bash
-lerobot-rollout \
-  --strategy.type=base \
+python examples/rtc/eval_with_real_robot.py \
   --policy.path=your-username/your-repo-id \
   --policy.device=cuda \
   --robot.type=unitree_g1 \
@@ -285,7 +284,7 @@ lerobot-rollout \
   --task="task_description" \
   --duration=1000 \
   --fps=30 \
-  --inference.type=rtc
+  --rtc.enabled=true
 ```
 
 ---

docs/source/using_dataset_tools.mdx

@@ -117,10 +117,10 @@ lerobot-edit-dataset \
     --repo_id lerobot/pusht_image \
     --operation.type convert_image_to_video \
     --operation.output_dir outputs/pusht_video \
-    --operation.camera_encoder_config.vcodec libsvtav1 \
-    --operation.camera_encoder_config.pix_fmt yuv420p \
-    --operation.camera_encoder_config.g 2 \
-    --operation.camera_encoder_config.crf 30
+    --operation.vcodec libsvtav1 \
+    --operation.pix_fmt yuv420p \
+    --operation.g 2 \
+    --operation.crf 30
 
 # Convert only specific episodes
 lerobot-edit-dataset \
@@ -147,14 +147,11 @@ lerobot-edit-dataset \
 **Parameters:**
 
 - `output_dir`: Custom output directory (optional - by default uses `new_repo_id` or `{repo_id}_video`)
-- `camera_encoder_config`: Video encoder settings — all sub-fields accessible via `--operation.camera_encoder_config.<field>`:
-  - `vcodec`: Video codec — `h264`, `hevc`, `libsvtav1`, `auto`, or hardware codecs (default: `libsvtav1`)
-  - `pix_fmt`: Pixel format — `yuv420p`, `yuv444p` (default: `yuv420p`)
-  - `g`: GOP size — lower values give better quality but larger files (default: 2)
-  - `crf`: Quality level — lower is better, 0 is lossless (default: 30)
-  - `preset`: Speed preset, libsvtav1 only (default: 12)
-  - `fast_decode`: Fast-decode tuning (default: 0)
-  - `encoder_threads`: Threads per encoder instance — global setting, separate from `camera_encoder_config` (default: None)
+- `vcodec`: Video codec to use - options: `h264`, `hevc`, `libsvtav1` (default: `libsvtav1`)
+- `pix_fmt`: Pixel format - options: `yuv420p`, `yuv444p` (default: `yuv420p`)
+- `g`: Group of pictures (GOP) size - lower values give better quality but larger files (default: 2)
+- `crf`: Constant rate factor - lower values give better quality but larger files, 0 is lossless (default: 30)
+- `fast_decode`: Fast decode tuning option (default: 0)
 - `episode_indices`: List of specific episodes to convert (default: all episodes)
 - `num_workers`: Number of parallel workers for processing (default: 4)
 

docs/source/xvla.mdx

@@ -220,7 +220,7 @@ REAL_DIM = 12
 # Postprocessing: Trim 20D predictions to 12D for deployment
 ```
 
-See the [action_hub.py](https://github.com/huggingface/lerobot/blob/main/src/lerobot/policies/xvla/action_hub.py) implementation for details.
+See the [action_hub.py](/home/jade_choghari/robot/lerobot/src/lerobot/policies/xvla/action_hub.py) implementation for details.
 
 #### Auto Action Mode (Recommended)
 
@@ -519,9 +519,9 @@ If you use X-VLA in your research, please cite:
 
 - [X-VLA Paper](https://arxiv.org/pdf/2510.10274)
 - [LeRobot Documentation](https://github.com/huggingface/lerobot)
-- [Action Registry Implementation](https://github.com/huggingface/lerobot/blob/main/src/lerobot/policies/xvla/action_hub.py)
-- [Processor Implementation](https://github.com/huggingface/lerobot/blob/main/src/lerobot/policies/xvla/processor_xvla.py)
-- [Model Configuration](https://github.com/huggingface/lerobot/blob/main/src/lerobot/policies/xvla/configuration_xvla.py)
+- [Action Registry Implementation](https://github.com/huggingface/lerobot/src/lerobot/policies/xvla/action_hub.py)
+- [Processor Implementation](https://github.com/huggingface/lerobot/src/lerobot/policies/xvla/processor_xvla.py)
+- [Model Configuration](https://github.com/huggingface/lerobot/src/lerobot/policies/xvla/configuration_xvla.py)
 
 ## Contributing
 

examples/dataset/slurm_compute_rabc.py

@@ -69,7 +69,7 @@ class ComputeProgressShards(PipelineStep):
         import torch
         from tqdm import tqdm
 
-        from lerobot.rewards.sarm.compute_rabc_weights import (
+        from lerobot.policies.sarm.compute_rabc_weights import (
             generate_all_frame_indices,
             interpolate_progress,
             load_sarm_resources,

examples/hil/hil_utils.py

@@ -0,0 +1,226 @@
+# Copyright 2025 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Shared utilities for Human-in-the-Loop data collection scripts."""
+
+import logging
+import time
+from dataclasses import dataclass, field
+from pathlib import Path
+
+from lerobot.common.control_utils import is_headless
+from lerobot.processor import (
+    IdentityProcessorStep,
+    RobotAction,
+    RobotObservation,
+    RobotProcessorPipeline,
+    observation_to_transition,
+    robot_action_observation_to_transition,
+    transition_to_observation,
+    transition_to_robot_action,
+)
+from lerobot.robots import Robot
+from lerobot.teleoperators import Teleoperator
+from lerobot.utils.robot_utils import precise_sleep
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass
+class HILDatasetConfig:
+    repo_id: str
+    single_task: str
+    root: str | Path | None = None
+    fps: int = 30
+    episode_time_s: float = 120
+    num_episodes: int = 50
+    video: bool = True
+    push_to_hub: bool = True
+    private: bool = False
+    tags: list[str] | None = None
+    num_image_writer_processes: int = 0
+    num_image_writer_threads_per_camera: int = 4
+    video_encoding_batch_size: int = 1
+    vcodec: str = "auto"
+    streaming_encoding: bool = True
+    encoder_queue_maxsize: int = 30
+    encoder_threads: int | None = None
+    rename_map: dict[str, str] = field(default_factory=dict)
+
+
+def teleop_has_motor_control(teleop: Teleoperator) -> bool:
+    """Check if teleoperator has motor control capabilities."""
+    return all(hasattr(teleop, attr) for attr in ("enable_torque", "disable_torque", "write_goal_positions"))
+
+
+def teleop_disable_torque(teleop: Teleoperator) -> None:
+    """Disable teleop torque if supported."""
+    if hasattr(teleop, "disable_torque"):
+        teleop.disable_torque()
+
+
+def teleop_enable_torque(teleop: Teleoperator) -> None:
+    """Enable teleop torque if supported."""
+    if hasattr(teleop, "enable_torque"):
+        teleop.enable_torque()
+
+
+def teleop_smooth_move_to(teleop: Teleoperator, target_pos: dict, duration_s: float = 2.0, fps: int = 50):
+    """Smoothly move teleop to target position if motor control is available."""
+    if not teleop_has_motor_control(teleop):
+        logger.warning("Teleop does not support motor control - cannot mirror robot position")
+        return
+
+    teleop_enable_torque(teleop)
+    current = teleop.get_action()
+    steps = max(int(duration_s * fps), 1)
+
+    for step in range(steps + 1):
+        t = step / steps
+        interp = {}
+        for k in current:
+            if k in target_pos:
+                interp[k] = current[k] * (1 - t) + target_pos[k] * t
+            else:
+                interp[k] = current[k]
+        teleop.write_goal_positions(interp)
+        time.sleep(1 / fps)
+
+
+def init_keyboard_listener():
+    """Initialize keyboard listener with HIL controls."""
+    events = {
+        "exit_early": False,
+        "rerecord_episode": False,
+        "stop_recording": False,
+        "policy_paused": False,
+        "correction_active": False,
+        "resume_policy": False,
+        "in_reset": False,
+        "start_next_episode": False,
+    }
+
+    if is_headless():
+        logger.warning("Headless environment - keyboard controls unavailable")
+        return None, events
+
+    from pynput import keyboard
+
+    def on_press(key):
+        try:
+            if events["in_reset"]:
+                if key in [keyboard.Key.space, keyboard.Key.right]:
+                    logger.info("[HIL] Starting next episode...")
+                    events["start_next_episode"] = True
+                elif hasattr(key, "char") and key.char == "c":
+                    events["start_next_episode"] = True
+                elif key == keyboard.Key.esc:
+                    logger.info("[HIL] ESC - Stop recording, pushing to hub...")
+                    events["stop_recording"] = True
+                    events["start_next_episode"] = True
+            else:
+                if key == keyboard.Key.space:
+                    if not events["policy_paused"] and not events["correction_active"]:
+                        logger.info("[HIL] PAUSED - Press 'c' to take control or 'p' to resume policy")
+                        events["policy_paused"] = True
+                elif hasattr(key, "char") and key.char == "c":
+                    if events["policy_paused"] and not events["correction_active"]:
+                        logger.info("[HIL] Taking control...")
+                        events["start_next_episode"] = True
+                elif hasattr(key, "char") and key.char == "p":
+                    if events["policy_paused"] or events["correction_active"]:
+                        logger.info("[HIL] Resuming policy...")
+                        events["resume_policy"] = True
+                elif key == keyboard.Key.right:
+                    logger.info("[HIL] End episode")
+                    events["exit_early"] = True
+                elif key == keyboard.Key.left:
+                    logger.info("[HIL] Re-record episode")
+                    events["rerecord_episode"] = True
+                    events["exit_early"] = True
+                elif key == keyboard.Key.esc:
+                    logger.info("[HIL] ESC - Stop recording...")
+                    events["stop_recording"] = True
+                    events["exit_early"] = True
+        except Exception as e:
+            logger.info(f"Key error: {e}")
+
+    listener = keyboard.Listener(on_press=on_press)
+    listener.start()
+    return listener, events
+
+
+def make_identity_processors():
+    """Create identity processors for recording."""
+    teleop_proc = RobotProcessorPipeline[tuple[RobotAction, RobotObservation], RobotAction](
+        steps=[IdentityProcessorStep()],
+        to_transition=robot_action_observation_to_transition,
+        to_output=transition_to_robot_action,
+    )
+    obs_proc = RobotProcessorPipeline[RobotObservation, RobotObservation](
+        steps=[IdentityProcessorStep()],
+        to_transition=observation_to_transition,
+        to_output=transition_to_observation,
+    )
+    return teleop_proc, obs_proc
+
+
+def reset_loop(robot: Robot, teleop: Teleoperator, events: dict, fps: int):
+    """Reset period where human repositions environment."""
+    logger.info("[HIL] RESET")
+
+    events["in_reset"] = True
+    events["start_next_episode"] = False
+
+    obs = robot.get_observation()
+    robot_pos = {k: v for k, v in obs.items() if k.endswith(".pos") and k in robot.observation_features}
+    teleop_smooth_move_to(teleop, robot_pos, duration_s=2.0, fps=50)
+
+    logger.info("Press any key to enable teleoperation")
+    while not events["start_next_episode"] and not events["stop_recording"]:
+        precise_sleep(0.05)
+
+    if events["stop_recording"]:
+        return
+
+    events["start_next_episode"] = False
+    teleop_disable_torque(teleop)
+    logger.info("Teleop enabled - press any key to start episode")
+
+    while not events["start_next_episode"] and not events["stop_recording"]:
+        loop_start = time.perf_counter()
+        action = teleop.get_action()
+        robot.send_action(action)
+        precise_sleep(1 / fps - (time.perf_counter() - loop_start))
+
+    events["in_reset"] = False
+    events["start_next_episode"] = False
+    events["exit_early"] = False
+    events["policy_paused"] = False
+    events["correction_active"] = False
+    events["resume_policy"] = False
+
+
+def print_controls(rtc: bool = False):
+    """Print control instructions."""
+    mode = "Human-in-the-Loop Data Collection" + (" (RTC)" if rtc else "")
+    logger.info(
+        "%s\n  Controls:\n"
+        "    SPACE  - Pause policy\n"
+        "    c      - Take control\n"
+        "    p      - Resume policy after pause/correction\n"
+        "    →      - End episode\n"
+        "    ESC    - Stop and push to hub",
+        mode,
+    )

examples/lekiwi/evaluate.py

@@ -14,21 +14,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import logging
-import time
-
-from lerobot.common.control_utils import init_keyboard_listener, predict_action
+from lerobot.common.control_utils import init_keyboard_listener
 from lerobot.datasets import LeRobotDataset
 from lerobot.policies import make_pre_post_processors
 from lerobot.policies.act import ACTPolicy
-from lerobot.policies.utils import make_robot_action
 from lerobot.processor import make_default_processors
 from lerobot.robots.lekiwi import LeKiwiClient, LeKiwiClientConfig
+from lerobot.scripts.lerobot_record import record_loop
 from lerobot.utils.constants import ACTION, OBS_STR
-from lerobot.utils.feature_utils import build_dataset_frame, hw_to_dataset_features
-from lerobot.utils.robot_utils import precise_sleep
+from lerobot.utils.feature_utils import hw_to_dataset_features
 from lerobot.utils.utils import log_say
-from lerobot.utils.visualization_utils import init_rerun, log_rerun_data
+from lerobot.utils.visualization_utils import init_rerun
 
 NUM_EPISODES = 2
 FPS = 30
@@ -39,9 +35,6 @@ HF_DATASET_ID = "<hf_username>/<eval_dataset_repo_id>"
 
 
 def main():
-    # NOTE: For production policy deployment, use `lerobot-rollout` CLI instead.
-    # This script provides a self-contained example for educational purposes.
-
     # Create the robot configuration & robot
     robot_config = LeKiwiClientConfig(remote_ip="172.18.134.136", id="lekiwi")
 
@@ -90,67 +83,43 @@ def main():
             raise ValueError("Robot is not connected!")
 
         print("Starting evaluate loop...")
-        control_interval = 1 / FPS
         recorded_episodes = 0
         while recorded_episodes < NUM_EPISODES and not events["stop_recording"]:
             log_say(f"Running inference, recording eval episode {recorded_episodes} of {NUM_EPISODES}")
 
-            # Inline evaluation loop: predict actions and send to robot
-            timestamp = 0
-            start_episode_t = time.perf_counter()
-            while timestamp < EPISODE_TIME_SEC:
-                start_loop_t = time.perf_counter()
-
-                if events["exit_early"]:
-                    events["exit_early"] = False
-                    break
-
-                # Get robot observation
-                obs = robot.get_observation()
-                obs_processed = robot_observation_processor(obs)
-                observation_frame = build_dataset_frame(dataset.features, obs_processed, prefix=OBS_STR)
-
-                # Predict action using the policy
-                action_tensor = predict_action(
-                    observation=observation_frame,
-                    policy=policy,
-                    device=policy.config.device,
-                    preprocessor=preprocessor,
-                    postprocessor=postprocessor,
-                    use_amp=policy.config.device.type == "cuda",
-                    task=TASK_DESCRIPTION,
-                    robot_type=robot.name,
-                )
-
-                # Convert policy output to robot action dict
-                action_values = make_robot_action(action_tensor, dataset.features)
-
-                # Process and send action to robot
-                robot_action_to_send = robot_action_processor((action_values, obs))
-                robot.send_action(robot_action_to_send)
-
-                # Write to dataset
-                action_frame = build_dataset_frame(dataset.features, action_values, prefix=ACTION)
-                frame = {**observation_frame, **action_frame, "task": TASK_DESCRIPTION}
-                dataset.add_frame(frame)
-
-                log_rerun_data(observation=obs_processed, action=action_values)
-
-                dt_s = time.perf_counter() - start_loop_t
-                sleep_time_s = control_interval - dt_s
-                if sleep_time_s < 0:
-                    logging.warning(
-                        f"Evaluate loop is running slower ({1 / dt_s:.1f} Hz) than the target FPS ({FPS} Hz)."
-                    )
-                precise_sleep(max(sleep_time_s, 0.0))
-                timestamp = time.perf_counter() - start_episode_t
+            # Main record loop
+            record_loop(
+                robot=robot,
+                events=events,
+                fps=FPS,
+                policy=policy,
+                preprocessor=preprocessor,  # Pass the pre and post policy processors
+                postprocessor=postprocessor,
+                dataset=dataset,
+                control_time_s=EPISODE_TIME_SEC,
+                single_task=TASK_DESCRIPTION,
+                display_data=True,
+                teleop_action_processor=teleop_action_processor,
+                robot_action_processor=robot_action_processor,
+                robot_observation_processor=robot_observation_processor,
+            )
 
             # Reset the environment if not stopping or re-recording
             if not events["stop_recording"] and (
                 (recorded_episodes < NUM_EPISODES - 1) or events["rerecord_episode"]
             ):
                 log_say("Reset the environment")
-                log_say("Waiting for environment reset, press right arrow key when ready...")
+                record_loop(
+                    robot=robot,
+                    events=events,
+                    fps=FPS,
+                    control_time_s=EPISODE_TIME_SEC,
+                    single_task=TASK_DESCRIPTION,
+                    display_data=True,
+                    teleop_action_processor=teleop_action_processor,
+                    robot_action_processor=robot_action_processor,
+                    robot_observation_processor=robot_observation_processor,
+                )
 
             if events["rerecord_episode"]:
                 log_say("Re-record episode")

examples/lekiwi/record.py

@@ -45,6 +45,9 @@ def main():
     leader_arm = SO100Leader(leader_arm_config)
     keyboard = KeyboardTeleop(keyboard_config)
 
+    # TODO(Steven): Update this example to use pipelines
+    teleop_action_processor, robot_action_processor, robot_observation_processor = make_default_processors()
+
     # Configure the dataset features
     action_features = hw_to_dataset_features(robot.action_features, ACTION)
     obs_features = hw_to_dataset_features(robot.observation_features, OBS_STR)
@@ -74,10 +77,6 @@ def main():
         if not robot.is_connected or not leader_arm.is_connected or not keyboard.is_connected:
             raise ValueError("Robot or teleop is not connected!")
 
-        teleop_action_processor, robot_action_processor, robot_observation_processor = (
-            make_default_processors()
-        )
-
         print("Starting record loop...")
         recorded_episodes = 0
         while recorded_episodes < NUM_EPISODES and not events["stop_recording"]:
@@ -88,14 +87,14 @@ def main():
                 robot=robot,
                 events=events,
                 fps=FPS,
-                teleop_action_processor=teleop_action_processor,
-                robot_action_processor=robot_action_processor,
-                robot_observation_processor=robot_observation_processor,
                 dataset=dataset,
                 teleop=[leader_arm, keyboard],
                 control_time_s=EPISODE_TIME_SEC,
                 single_task=TASK_DESCRIPTION,
                 display_data=True,
+                teleop_action_processor=teleop_action_processor,
+                robot_action_processor=robot_action_processor,
+                robot_observation_processor=robot_observation_processor,
             )
 
             # Reset the environment if not stopping or re-recording
@@ -107,13 +106,13 @@ def main():
                     robot=robot,
                     events=events,
                     fps=FPS,
-                    teleop_action_processor=teleop_action_processor,
-                    robot_action_processor=robot_action_processor,
-                    robot_observation_processor=robot_observation_processor,
                     teleop=[leader_arm, keyboard],
                     control_time_s=RESET_TIME_SEC,
                     single_task=TASK_DESCRIPTION,
                     display_data=True,
+                    teleop_action_processor=teleop_action_processor,
+                    robot_action_processor=robot_action_processor,
+                    robot_observation_processor=robot_observation_processor,
                 )
 
             if events["rerecord_episode"]:

examples/lekiwi/rollout.py

@@ -1,77 +0,0 @@
-# !/usr/bin/env python
-
-# Copyright 2025 The HuggingFace Inc. team. All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-"""Run a trained policy on LeKiwi without recording (base rollout).
-
-Uses the rollout engine's :class:`BaseStrategy` (autonomous execution,
-no dataset) with :class:`SyncInferenceConfig` (inline policy call per
-control tick).  For a CLI entry point with the same capabilities plus
-recording, upload, and human-in-the-loop variants, see ``lerobot-rollout``.
-"""
-
-from lerobot.configs import PreTrainedConfig
-from lerobot.robots.lekiwi import LeKiwiClientConfig
-from lerobot.rollout import BaseStrategyConfig, RolloutConfig, build_rollout_context
-from lerobot.rollout.inference import SyncInferenceConfig
-from lerobot.rollout.strategies import BaseStrategy
-from lerobot.utils.process import ProcessSignalHandler
-from lerobot.utils.utils import init_logging
-
-FPS = 30
-DURATION_SEC = 60
-TASK_DESCRIPTION = "My task description"
-HF_MODEL_ID = "<hf_username>/<model_repo_id>"
-
-
-def main():
-    init_logging()
-
-    # Robot: LeKiwi client — make sure lekiwi_host is already running on the robot.
-    robot_config = LeKiwiClientConfig(remote_ip="172.18.134.136", id="lekiwi")
-
-    # Policy: load the pretrained config.  ``pretrained_path`` is read downstream
-    # by ``build_rollout_context`` to reload the full model.
-    policy_config = PreTrainedConfig.from_pretrained(HF_MODEL_ID)
-    policy_config.pretrained_path = HF_MODEL_ID
-
-    # Assemble the rollout config: base strategy (no recording) + sync inference.
-    cfg = RolloutConfig(
-        robot=robot_config,
-        policy=policy_config,
-        strategy=BaseStrategyConfig(),
-        inference=SyncInferenceConfig(),
-        fps=FPS,
-        duration=DURATION_SEC,
-        task=TASK_DESCRIPTION,
-    )
-
-    # Graceful Ctrl-C: the strategy loop exits when shutdown_event is set.
-    signal_handler = ProcessSignalHandler(use_threads=True)
-
-    # Build the context (connects robot, loads policy, wires the inference strategy).
-    # No custom processors here — LeKiwi runs on raw joint features.
-    ctx = build_rollout_context(cfg, signal_handler.shutdown_event)
-
-    strategy = BaseStrategy(cfg.strategy)
-    try:
-        strategy.setup(ctx)
-        strategy.run(ctx)
-    finally:
-        strategy.teardown(ctx)
-
-
-if __name__ == "__main__":
-    main()

examples/phone_to_so100/evaluate.py

@@ -14,17 +14,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import logging
-import time
-
 from lerobot.cameras.opencv import OpenCVCameraConfig
-from lerobot.common.control_utils import init_keyboard_listener, predict_action
+from lerobot.common.control_utils import init_keyboard_listener
 from lerobot.configs import FeatureType, PolicyFeature
 from lerobot.datasets import LeRobotDataset, aggregate_pipeline_dataset_features, create_initial_features
 from lerobot.model.kinematics import RobotKinematics
 from lerobot.policies import make_pre_post_processors
 from lerobot.policies.act import ACTPolicy
-from lerobot.policies.utils import make_robot_action
 from lerobot.processor import (
     RobotProcessorPipeline,
     make_default_teleop_action_processor,
@@ -38,12 +34,11 @@ from lerobot.robots.so_follower.robot_kinematic_processor import (
     ForwardKinematicsJointsToEE,
     InverseKinematicsEEToJoints,
 )
+from lerobot.scripts.lerobot_record import record_loop
 from lerobot.types import RobotAction, RobotObservation
-from lerobot.utils.constants import ACTION, OBS_STR
-from lerobot.utils.feature_utils import build_dataset_frame, combine_feature_dicts
-from lerobot.utils.robot_utils import precise_sleep
+from lerobot.utils.feature_utils import combine_feature_dicts
 from lerobot.utils.utils import log_say
-from lerobot.utils.visualization_utils import init_rerun, log_rerun_data
+from lerobot.utils.visualization_utils import init_rerun
 
 NUM_EPISODES = 5
 FPS = 30
@@ -54,9 +49,6 @@ HF_DATASET_ID = "<hf_username>/<dataset_repo_id>"
 
 
 def main():
-    # NOTE: For production policy deployment, use `lerobot-rollout` CLI instead.
-    # This script provides a self-contained example for educational purposes.
-
     # Create the robot configuration & robot
     camera_config = {"front": OpenCVCameraConfig(index_or_path=0, width=640, height=480, fps=FPS)}
     robot_config = SO100FollowerConfig(
@@ -151,67 +143,43 @@ def main():
             raise ValueError("Robot is not connected!")
 
         print("Starting evaluate loop...")
-        control_interval = 1 / FPS
         episode_idx = 0
         for episode_idx in range(NUM_EPISODES):
             log_say(f"Running inference, recording eval episode {episode_idx + 1} of {NUM_EPISODES}")
 
-            # Inline evaluation loop: predict actions and send to robot
-            timestamp = 0
-            start_episode_t = time.perf_counter()
-            while timestamp < EPISODE_TIME_SEC:
-                start_loop_t = time.perf_counter()
-
-                if events["exit_early"]:
-                    events["exit_early"] = False
-                    break
-
-                # Get robot observation
-                obs = robot.get_observation()
-                obs_processed = robot_joints_to_ee_pose_processor(obs)
-                observation_frame = build_dataset_frame(dataset.features, obs_processed, prefix=OBS_STR)
-
-                # Predict action using the policy
-                action_tensor = predict_action(
-                    observation=observation_frame,
-                    policy=policy,
-                    device=policy.config.device,
-                    preprocessor=preprocessor,
-                    postprocessor=postprocessor,
-                    use_amp=policy.config.device.type == "cuda",
-                    task=TASK_DESCRIPTION,
-                    robot_type=robot.name,
-                )
-
-                # Convert policy output to robot action dict
-                action_values = make_robot_action(action_tensor, dataset.features)
-
-                # Process and send action to robot (EE -> joints via IK)
-                robot_action_to_send = robot_ee_to_joints_processor((action_values, obs))
-                robot.send_action(robot_action_to_send)
-
-                # Write to dataset
-                action_frame = build_dataset_frame(dataset.features, action_values, prefix=ACTION)
-                frame = {**observation_frame, **action_frame, "task": TASK_DESCRIPTION}
-                dataset.add_frame(frame)
-
-                log_rerun_data(observation=obs_processed, action=action_values)
-
-                dt_s = time.perf_counter() - start_loop_t
-                sleep_time_s = control_interval - dt_s
-                if sleep_time_s < 0:
-                    logging.warning(
-                        f"Evaluate loop is running slower ({1 / dt_s:.1f} Hz) than the target FPS ({FPS} Hz)."
-                    )
-                precise_sleep(max(sleep_time_s, 0.0))
-                timestamp = time.perf_counter() - start_episode_t
+            # Main record loop
+            record_loop(
+                robot=robot,
+                events=events,
+                fps=FPS,
+                policy=policy,
+                preprocessor=preprocessor,  # Pass the pre and post policy processors
+                postprocessor=postprocessor,
+                dataset=dataset,
+                control_time_s=EPISODE_TIME_SEC,
+                single_task=TASK_DESCRIPTION,
+                display_data=True,
+                teleop_action_processor=make_default_teleop_action_processor(),
+                robot_action_processor=robot_ee_to_joints_processor,
+                robot_observation_processor=robot_joints_to_ee_pose_processor,
+            )
 
             # Reset the environment if not stopping or re-recording
             if not events["stop_recording"] and (
                 (episode_idx < NUM_EPISODES - 1) or events["rerecord_episode"]
             ):
                 log_say("Reset the environment")
-                log_say("Waiting for environment reset, press right arrow key when ready...")
+                record_loop(
+                    robot=robot,
+                    events=events,
+                    fps=FPS,
+                    control_time_s=EPISODE_TIME_SEC,
+                    single_task=TASK_DESCRIPTION,
+                    display_data=True,
+                    teleop_action_processor=make_default_teleop_action_processor(),
+                    robot_action_processor=robot_ee_to_joints_processor,
+                    robot_observation_processor=robot_joints_to_ee_pose_processor,
+                )
 
             if events["rerecord_episode"]:
                 log_say("Re-record episode")
@@ -222,6 +190,7 @@ def main():
 
             # Save episode
             dataset.save_episode()
+            episode_idx += 1
     finally:
         # Clean up
         log_say("Stop recording")

examples/phone_to_so100/record.py

@@ -65,15 +65,14 @@ def main():
     robot = SO100Follower(robot_config)
     phone = Phone(teleop_config)
 
-    # NOTE: It is highly recommended to use the urdf in the SO-ARM100 repo:
-    #   https://github.com/TheRobotStudio/SO-ARM100/blob/main/Simulation/SO101/so101_new_calib.urdf
+    # NOTE: It is highly recommended to use the urdf in the SO-ARM100 repo: https://github.com/TheRobotStudio/SO-ARM100/blob/main/Simulation/SO101/so101_new_calib.urdf
     kinematics_solver = RobotKinematics(
         urdf_path="./SO101/so101_new_calib.urdf",
         target_frame_name="gripper_frame_link",
         joint_names=list(robot.bus.motors.keys()),
     )
 
-    # Build pipeline to convert phone action to EE action (with gripper velocity mapped to joint).
+    # Build pipeline to convert phone action to EE action
     phone_to_robot_ee_pose_processor = RobotProcessorPipeline[
         tuple[RobotAction, RobotObservation], RobotAction
     ](
@@ -95,7 +94,7 @@ def main():
         to_output=transition_to_robot_action,
     )
 
-    # Build pipeline to convert EE action to joints action (IK).
+    # Build pipeline to convert EE action to joints action
     robot_ee_to_joints_processor = RobotProcessorPipeline[tuple[RobotAction, RobotObservation], RobotAction](
         steps=[
             InverseKinematicsEEToJoints(
@@ -108,7 +107,7 @@ def main():
         to_output=transition_to_robot_action,
     )
 
-    # Build pipeline to convert joint observation to EE observation (FK).
+    # Build pipeline to convert joint observation to EE observation
     robot_joints_to_ee_pose = RobotProcessorPipeline[RobotObservation, RobotObservation](
         steps=[
             ForwardKinematicsJointsToEE(
@@ -119,12 +118,13 @@ def main():
         to_output=transition_to_observation,
     )
 
-    # Create the dataset, deriving features from the pipelines so the on-disk schema
-    # matches exactly what the pipelines produce at runtime.
+    # Create the dataset
     dataset = LeRobotDataset.create(
         repo_id=HF_REPO_ID,
         fps=FPS,
         features=combine_feature_dicts(
+            # Run the feature contract of the pipelines
+            # This tells you how the features would look like after the pipeline steps
             aggregate_pipeline_dataset_features(
                 pipeline=phone_to_robot_ee_pose_processor,
                 initial_features=create_initial_features(action=phone.action_features),
@@ -163,14 +163,14 @@ def main():
                 robot=robot,
                 events=events,
                 fps=FPS,
-                teleop_action_processor=phone_to_robot_ee_pose_processor,
-                robot_action_processor=robot_ee_to_joints_processor,
-                robot_observation_processor=robot_joints_to_ee_pose,
                 teleop=phone,
                 dataset=dataset,
                 control_time_s=EPISODE_TIME_SEC,
                 single_task=TASK_DESCRIPTION,
                 display_data=True,
+                teleop_action_processor=phone_to_robot_ee_pose_processor,
+                robot_action_processor=robot_ee_to_joints_processor,
+                robot_observation_processor=robot_joints_to_ee_pose,
             )
 
             # Reset the environment if not stopping or re-recording
@@ -182,13 +182,13 @@ def main():
                     robot=robot,
                     events=events,
                     fps=FPS,
-                    teleop_action_processor=phone_to_robot_ee_pose_processor,
-                    robot_action_processor=robot_ee_to_joints_processor,
-                    robot_observation_processor=robot_joints_to_ee_pose,
                     teleop=phone,
                     control_time_s=RESET_TIME_SEC,
                     single_task=TASK_DESCRIPTION,
                     display_data=True,
+                    teleop_action_processor=phone_to_robot_ee_pose_processor,
+                    robot_action_processor=robot_ee_to_joints_processor,
+                    robot_observation_processor=robot_joints_to_ee_pose,
                 )
 
             if events["rerecord_episode"]:

examples/phone_to_so100/rollout.py

@@ -1,126 +0,0 @@
-# !/usr/bin/env python
-
-# Copyright 2025 The HuggingFace Inc. team. All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-"""Run a trained EE-space policy on SO100 (phone-trained) without recording.
-
-Mirrors ``examples/so100_to_so100_EE/rollout.py`` — the model was trained
-with phone teleoperation in EE space, so at deployment we only need the
-joint↔EE conversion on the robot side; the phone is not used.
-
-Uses :class:`BaseStrategy` (no recording) + :class:`SyncInferenceConfig`
-(inline policy call).  For recording during rollout, switch to Sentry,
-Highlight, or DAgger via ``lerobot-rollout --strategy.type=...``.
-"""
-
-from lerobot.cameras.opencv import OpenCVCameraConfig
-from lerobot.configs import PreTrainedConfig
-from lerobot.model.kinematics import RobotKinematics
-from lerobot.processor import (
-    RobotProcessorPipeline,
-    observation_to_transition,
-    robot_action_observation_to_transition,
-    transition_to_observation,
-    transition_to_robot_action,
-)
-from lerobot.robots.so_follower import SO100Follower, SO100FollowerConfig
-from lerobot.robots.so_follower.robot_kinematic_processor import (
-    ForwardKinematicsJointsToEE,
-    InverseKinematicsEEToJoints,
-)
-from lerobot.rollout import BaseStrategyConfig, RolloutConfig, build_rollout_context
-from lerobot.rollout.inference import SyncInferenceConfig
-from lerobot.rollout.strategies import BaseStrategy
-from lerobot.types import RobotAction, RobotObservation
-from lerobot.utils.process import ProcessSignalHandler
-from lerobot.utils.utils import init_logging
-
-FPS = 30
-DURATION_SEC = 60
-TASK_DESCRIPTION = "My task description"
-HF_MODEL_ID = "<hf_username>/<model_repo_id>"
-
-
-def main():
-    init_logging()
-
-    camera_config = {"front": OpenCVCameraConfig(index_or_path=0, width=640, height=480, fps=FPS)}
-    robot_config = SO100FollowerConfig(
-        port="/dev/tty.usbmodem58760434471",
-        id="my_awesome_follower_arm",
-        cameras=camera_config,
-        use_degrees=True,
-    )
-
-    # Peek at motor names once to build the kinematic solver.
-    temp_robot = SO100Follower(robot_config)
-    motor_names = list(temp_robot.bus.motors.keys())
-
-    kinematics_solver = RobotKinematics(
-        urdf_path="./SO101/so101_new_calib.urdf",
-        target_frame_name="gripper_frame_link",
-        joint_names=motor_names,
-    )
-
-    robot_joints_to_ee_pose_processor = RobotProcessorPipeline[RobotObservation, RobotObservation](
-        steps=[ForwardKinematicsJointsToEE(kinematics=kinematics_solver, motor_names=motor_names)],
-        to_transition=observation_to_transition,
-        to_output=transition_to_observation,
-    )
-
-    robot_ee_to_joints_processor = RobotProcessorPipeline[tuple[RobotAction, RobotObservation], RobotAction](
-        steps=[
-            InverseKinematicsEEToJoints(
-                kinematics=kinematics_solver,
-                motor_names=motor_names,
-                initial_guess_current_joints=True,
-            ),
-        ],
-        to_transition=robot_action_observation_to_transition,
-        to_output=transition_to_robot_action,
-    )
-
-    policy_config = PreTrainedConfig.from_pretrained(HF_MODEL_ID)
-    policy_config.pretrained_path = HF_MODEL_ID
-
-    cfg = RolloutConfig(
-        robot=robot_config,
-        policy=policy_config,
-        strategy=BaseStrategyConfig(),
-        inference=SyncInferenceConfig(),
-        fps=FPS,
-        duration=DURATION_SEC,
-        task=TASK_DESCRIPTION,
-    )
-
-    signal_handler = ProcessSignalHandler(use_threads=True)
-
-    ctx = build_rollout_context(
-        cfg,
-        signal_handler.shutdown_event,
-        robot_action_processor=robot_ee_to_joints_processor,
-        robot_observation_processor=robot_joints_to_ee_pose_processor,
-    )
-
-    strategy = BaseStrategy(cfg.strategy)
-    try:
-        strategy.setup(ctx)
-        strategy.run(ctx)
-    finally:
-        strategy.teardown(ctx)
-
-
-if __name__ == "__main__":
-    main()

examples/rtc/eval_with_real_robot.py

@@ -0,0 +1,673 @@
+#!/usr/bin/env python
+
+# Copyright 2025 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Demo script showing how to use Real-Time Chunking (RTC) with action chunking policies on real robots.
+
+This script demonstrates:
+1. Creating a robot and policy (SmolVLA, Pi0, etc.) with RTC
+2. Consuming actions from the policy while the robot executes
+3. Periodically requesting new action chunks in the background using threads
+4. Managing action buffers and timing for real-time operation
+
+For simulation environments, see eval_with_simulation.py
+
+Usage:
+    # Run RTC with Real robot with RTC
+    uv run examples/rtc/eval_with_real_robot.py \
+        --policy.path=<USER>/smolvla_check_rtc_last3 \
+        --policy.device=mps \
+        --rtc.enabled=true \
+        --rtc.execution_horizon=20 \
+        --robot.type=so100_follower \
+        --robot.port=/dev/tty.usbmodem58FA0834591 \
+        --robot.id=so100_follower \
+        --robot.cameras="{ gripper: {type: opencv, index_or_path: 1, width: 640, height: 480, fps: 30}, front: {type: opencv, index_or_path: 0, width: 640, height: 480, fps: 30}}" \
+        --task="Move green small object into the purple platform" \
+        --duration=120
+
+    # Run RTC with Real robot without RTC
+    uv run examples/rtc/eval_with_real_robot.py \
+        --policy.path=<USER>/smolvla_check_rtc_last3 \
+        --policy.device=mps \
+        --rtc.enabled=false \
+        --robot.type=so100_follower \
+        --robot.port=/dev/tty.usbmodem58FA0834591 \
+        --robot.id=so100_follower \
+        --robot.cameras="{ gripper: {type: opencv, index_or_path: 1, width: 640, height: 480, fps: 30}, front: {type: opencv, index_or_path: 0, width: 640, height: 480, fps: 30}}" \
+        --task="Move green small object into the purple platform" \
+        --duration=120
+
+    # Run RTC with Real robot with pi0.5 policy
+    uv run examples/rtc/eval_with_real_robot.py \
+        --policy.path=<USER>/pi05_check_rtc \
+        --policy.device=mps \
+        --rtc.enabled=true \
+        --rtc.execution_horizon=20 \
+        --robot.type=so100_follower \
+        --robot.port=/dev/tty.usbmodem58FA0834591 \
+        --robot.id=so100_follower \
+        --robot.cameras="{ gripper: {type: opencv, index_or_path: 0, width: 640, height: 480, fps: 30}, front: {type: opencv, index_or_path: 1, width: 640, height: 480, fps: 30}}" \
+        --task="Move green small object into the purple platform" \
+        --duration=120
+
+    # Run RTC with bi_openarm_follower (dual-arm OpenArms) and pi0.5 policy
+    python examples/rtc/eval_with_real_robot.py \
+        --policy.path=lerobot-data-collection/folding_final \
+        --robot.type=bi_openarm_follower \
+        --robot.cameras='{left_wrist: {type: opencv, index_or_path: "/dev/video4", width: 1280, height: 720, fps: 30}, base: {type: opencv, index_or_path: "/dev/video2", width: 640, height: 480, fps: 30}, right_wrist: {type: opencv, index_or_path: "/dev/video0", width: 1280, height: 720, fps: 30}}' \
+        --robot.left_arm_config.port=can0 \
+        --robot.left_arm_config.side=left \
+        --robot.left_arm_config.can_interface=socketcan \
+        --robot.left_arm_config.disable_torque_on_disconnect=true \
+        --robot.left_arm_config.max_relative_target=8.0 \
+        --robot.right_arm_config.port=can1 \
+        --robot.right_arm_config.side=right \
+        --robot.right_arm_config.can_interface=socketcan \
+        --robot.right_arm_config.disable_torque_on_disconnect=true \
+        --robot.right_arm_config.max_relative_target=8.0 \
+        --task="Fold the T-shirt properly" \
+        --fps=30 \
+        --duration=2000 \
+        --interpolation_multiplier=3 \
+        --rtc.enabled=true \
+        --rtc.execution_horizon=20 \
+        --rtc.max_guidance_weight=5.0 \
+        --rtc.prefix_attention_schedule=LINEAR \
+        --device=cuda
+"""
+
+import logging
+import math
+import sys
+import time
+import traceback
+from dataclasses import dataclass, field
+from threading import Event, Lock, Thread
+
+import torch
+from torch import Tensor
+
+from lerobot.cameras.opencv import OpenCVCameraConfig  # noqa: F401
+from lerobot.cameras.realsense import RealSenseCameraConfig  # noqa: F401
+from lerobot.cameras.zmq import ZMQCameraConfig  # noqa: F401
+from lerobot.configs import PreTrainedConfig, RTCAttentionSchedule, parser
+from lerobot.policies import get_policy_class, make_pre_post_processors
+from lerobot.policies.rtc import ActionInterpolator, ActionQueue, LatencyTracker, RTCConfig
+from lerobot.processor import (
+    NormalizerProcessorStep,
+    RelativeActionsProcessorStep,
+    TransitionKey,
+    create_transition,
+    make_default_robot_action_processor,
+    make_default_robot_observation_processor,
+    to_relative_actions,
+)
+from lerobot.rl.process import ProcessSignalHandler
+from lerobot.robots import (  # noqa: F401
+    Robot,
+    RobotConfig,
+    bi_openarm_follower,
+    bi_so_follower,
+    koch_follower,
+    so_follower,
+    unitree_g1,
+)
+from lerobot.robots.utils import make_robot_from_config
+from lerobot.utils.constants import OBS_IMAGES, OBS_STATE
+from lerobot.utils.feature_utils import build_dataset_frame, hw_to_dataset_features
+from lerobot.utils.hub import HubMixin
+from lerobot.utils.utils import init_logging
+
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+
+class RobotWrapper:
+    def __init__(self, robot: Robot):
+        self.robot = robot
+        self.lock = Lock()
+
+    def get_observation(self) -> dict[str, Tensor]:
+        with self.lock:
+            return self.robot.get_observation()
+
+    def send_action(self, action: Tensor):
+        with self.lock:
+            self.robot.send_action(action)
+
+    def observation_features(self) -> list[str]:
+        with self.lock:
+            return self.robot.observation_features
+
+    def action_features(self) -> list[str]:
+        with self.lock:
+            return self.robot.action_features
+
+
+@dataclass
+class RTCDemoConfig(HubMixin):
+    """Configuration for RTC demo with action chunking policies and real robots."""
+
+    # Policy configuration
+    policy: PreTrainedConfig | None = None
+
+    # Robot configuration
+    robot: RobotConfig | None = None
+
+    # RTC configuration
+    rtc: RTCConfig = field(
+        default_factory=lambda: RTCConfig(
+            execution_horizon=10,
+            max_guidance_weight=1.0,
+            prefix_attention_schedule=RTCAttentionSchedule.EXP,
+        )
+    )
+
+    # Demo parameters
+    duration: float = 30.0  # Duration to run the demo (seconds)
+    fps: float = 10.0  # Action execution frequency (Hz)
+    interpolation_multiplier: int = 1  # Control rate multiplier (1=off, 2=2x, 3=3x)
+
+    # Compute device
+    device: str | None = None  # Device to run on (cuda, cpu, auto)
+
+    # Get new actions horizon. The amount of executed steps after which will be requested new actions.
+    # It should be higher than inference delay + execution horizon.
+    action_queue_size_to_get_new_actions: int = 30
+
+    # Task to execute
+    task: str = field(default="", metadata={"help": "Task to execute"})
+
+    # Torch compile configuration
+    use_torch_compile: bool = field(
+        default=False,
+        metadata={"help": "Use torch.compile for faster inference (PyTorch 2.0+)"},
+    )
+
+    torch_compile_backend: str = field(
+        default="inductor",
+        metadata={"help": "Backend for torch.compile (inductor, aot_eager, cudagraphs)"},
+    )
+
+    torch_compile_mode: str = field(
+        default="default",
+        metadata={"help": "Compilation mode (default, reduce-overhead, max-autotune)"},
+    )
+
+    torch_compile_disable_cudagraphs: bool = field(
+        default=True,
+        metadata={
+            "help": "Disable CUDA graphs in torch.compile. Required due to in-place tensor "
+            "operations in denoising loop (x_t += dt * v_t) which cause tensor aliasing issues."
+        },
+    )
+
+    def __post_init__(self):
+        # HACK: We parse again the cli args here to get the pretrained path if there was one.
+        policy_path = parser.get_path_arg("policy")
+        if policy_path:
+            cli_overrides = parser.get_cli_overrides("policy")
+            self.policy = PreTrainedConfig.from_pretrained(policy_path, cli_overrides=cli_overrides)
+            self.policy.pretrained_path = policy_path
+        else:
+            raise ValueError("Policy path is required")
+
+        # Validate that robot configuration is provided
+        if self.robot is None:
+            raise ValueError("Robot configuration must be provided")
+
+    @classmethod
+    def __get_path_fields__(cls) -> list[str]:
+        """This enables the parser to load config from the policy using `--policy.path=local/dir`"""
+        return ["policy"]
+
+
+def is_image_key(k: str) -> bool:
+    return k.startswith(OBS_IMAGES)
+
+
+def _reanchor_relative_rtc_prefix(
+    prev_actions_absolute: Tensor,
+    current_state: Tensor,
+    relative_step: RelativeActionsProcessorStep,
+    normalizer_step: NormalizerProcessorStep | None,
+    policy_device: torch.device | str,
+) -> Tensor:
+    """Convert absolute leftovers into model-space for relative-action RTC policies.
+
+    When a policy uses relative actions, the RTC prefix (leftover actions from
+    the previous chunk) is stored in absolute space. Before feeding it back to
+    the policy we need to re-express it relative to the *current* robot state
+    and then re-normalize.
+    """
+    state = current_state.detach().cpu()
+    if state.dim() == 1:
+        state = state.unsqueeze(0)
+
+    action_cpu = prev_actions_absolute.detach().cpu()
+    mask = relative_step._build_mask(action_cpu.shape[-1])
+    relative_actions = to_relative_actions(action_cpu, state, mask)
+
+    transition = create_transition(action=relative_actions)
+    if normalizer_step is not None:
+        transition = normalizer_step(transition)
+
+    return transition[TransitionKey.ACTION].to(policy_device)
+
+
+def get_actions(
+    policy,
+    robot: RobotWrapper,
+    robot_observation_processor,
+    action_queue: ActionQueue,
+    shutdown_event: Event,
+    cfg: RTCDemoConfig,
+):
+    """Thread function to request action chunks from the policy.
+
+    Args:
+        policy: The policy instance (SmolVLA, Pi0, etc.)
+        robot: The robot instance for getting observations
+        robot_observation_processor: Processor for raw robot observations
+        action_queue: Queue to put new action chunks
+        shutdown_event: Event to signal shutdown
+        cfg: Demo configuration
+    """
+    try:
+        logger.info("[GET_ACTIONS] Starting get actions thread")
+
+        latency_tracker = LatencyTracker()  # Track latency of action chunks
+        fps = cfg.fps
+        time_per_chunk = 1.0 / fps
+
+        # Only keep .pos joints + camera streams if the policy was trained on positions,
+        # not the full pos/vel/torque state the robot exposes.
+        observation_features_hw = {
+            key: value
+            for key, value in robot.observation_features().items()
+            if key.endswith(".pos") or isinstance(value, tuple)
+        }
+
+        dataset_features = hw_to_dataset_features(observation_features_hw, "observation")
+        policy_device = policy.config.device
+
+        # Load preprocessor and postprocessor from pretrained files
+        # The stats are embedded in the processor .safetensors files
+        logger.info(f"[GET_ACTIONS] Loading preprocessor/postprocessor from {cfg.policy.pretrained_path}")
+
+        preprocessor, postprocessor = make_pre_post_processors(
+            policy_cfg=cfg.policy,
+            pretrained_path=cfg.policy.pretrained_path,
+            dataset_stats=None,  # Will load from pretrained processor files
+            preprocessor_overrides={
+                "device_processor": {"device": cfg.policy.device},
+            },
+        )
+
+        logger.info("[GET_ACTIONS] Preprocessor/postprocessor loaded successfully with embedded stats")
+
+        relative_step = next(
+            (s for s in preprocessor.steps if isinstance(s, RelativeActionsProcessorStep) and s.enabled),
+            None,
+        )
+        normalizer_step = next(
+            (s for s in preprocessor.steps if isinstance(s, NormalizerProcessorStep)),
+            None,
+        )
+        if relative_step is not None:
+            if relative_step.action_names is None:
+                cfg_names = getattr(cfg.policy, "action_feature_names", None)
+                if cfg_names:
+                    relative_step.action_names = list(cfg_names)
+                else:
+                    relative_step.action_names = [
+                        k for k in robot.robot.action_features if k.endswith(".pos")
+                    ]
+            logger.info("[GET_ACTIONS] Relative actions enabled: will re-anchor RTC prefix")
+
+        get_actions_threshold = cfg.action_queue_size_to_get_new_actions
+
+        if not cfg.rtc.enabled:
+            get_actions_threshold = 0
+
+        while not shutdown_event.is_set():
+            if action_queue.qsize() <= get_actions_threshold:
+                current_time = time.perf_counter()
+                action_index_before_inference = action_queue.get_action_index()
+                prev_actions = action_queue.get_left_over()
+
+                inference_latency = latency_tracker.max()
+                inference_delay = math.ceil(inference_latency / time_per_chunk)
+
+                obs = robot.get_observation()
+
+                # Apply robot observation processor
+                obs_processed = robot_observation_processor(obs)
+
+                obs_with_policy_features = build_dataset_frame(
+                    dataset_features, obs_processed, prefix="observation"
+                )
+
+                for name in obs_with_policy_features:
+                    obs_with_policy_features[name] = torch.from_numpy(obs_with_policy_features[name])
+                    if "image" in name:
+                        obs_with_policy_features[name] = (
+                            obs_with_policy_features[name].type(torch.float32) / 255
+                        )
+                        obs_with_policy_features[name] = (
+                            obs_with_policy_features[name].permute(2, 0, 1).contiguous()
+                        )
+                    obs_with_policy_features[name] = obs_with_policy_features[name].unsqueeze(0)
+                    obs_with_policy_features[name] = obs_with_policy_features[name].to(policy_device)
+
+                obs_with_policy_features["task"] = [cfg.task]  # Task should be a list, not a string!
+                obs_with_policy_features["robot_type"] = (
+                    robot.robot.name if hasattr(robot.robot, "name") else ""
+                )
+
+                preproceseded_obs = preprocessor(obs_with_policy_features)
+
+                # Re-anchor leftover actions for relative-action policies.
+                # We need the *postprocessed* (absolute) leftover, not the original
+                # (normalized/relative) one that get_left_over() returns.
+                if (
+                    prev_actions is not None
+                    and relative_step is not None
+                    and OBS_STATE in obs_with_policy_features
+                ):
+                    with action_queue.lock:
+                        if action_queue.queue is not None:
+                            prev_actions_abs = action_queue.queue[action_queue.last_index :].clone()
+                        else:
+                            prev_actions_abs = None
+                    if prev_actions_abs is not None and prev_actions_abs.numel() > 0:
+                        prev_actions = _reanchor_relative_rtc_prefix(
+                            prev_actions_absolute=prev_actions_abs,
+                            current_state=obs_with_policy_features[OBS_STATE],
+                            relative_step=relative_step,
+                            normalizer_step=normalizer_step,
+                            policy_device=policy_device,
+                        )
+
+                # Generate actions WITH RTC
+                actions = policy.predict_action_chunk(
+                    preproceseded_obs,
+                    inference_delay=inference_delay,
+                    prev_chunk_left_over=prev_actions,
+                )
+
+                # Store original actions (before postprocessing) for RTC
+                original_actions = actions.squeeze(0).clone()
+
+                postprocessed_actions = postprocessor(actions)
+
+                postprocessed_actions = postprocessed_actions.squeeze(0)
+
+                new_latency = time.perf_counter() - current_time
+                new_delay = math.ceil(new_latency / time_per_chunk)
+                latency_tracker.add(new_latency)
+
+                if cfg.action_queue_size_to_get_new_actions < cfg.rtc.execution_horizon + new_delay:
+                    logger.warning(
+                        "[GET_ACTIONS] cfg.action_queue_size_to_get_new_actions Too small, It should be higher than inference delay + execution horizon."
+                    )
+
+                action_queue.merge(
+                    original_actions, postprocessed_actions, new_delay, action_index_before_inference
+                )
+            else:
+                # Small sleep to prevent busy waiting
+                time.sleep(0.1)
+
+        logger.info("[GET_ACTIONS] get actions thread shutting down")
+    except Exception as e:
+        logger.error(f"[GET_ACTIONS] Fatal exception in get_actions thread: {e}")
+        logger.error(traceback.format_exc())
+        sys.exit(1)
+
+
+def actor_control(
+    robot: RobotWrapper,
+    robot_action_processor,
+    action_queue: ActionQueue,
+    shutdown_event: Event,
+    cfg: RTCDemoConfig,
+):
+    """Thread function to execute actions on the robot.
+
+    Args:
+        robot: The robot instance
+        action_queue: Queue to get actions from
+        shutdown_event: Event to signal shutdown
+        cfg: Demo configuration
+    """
+    try:
+        logger.info("[ACTOR] Starting actor thread")
+
+        action_keys = [k for k in robot.action_features() if k.endswith(".pos")]
+
+        action_count = 0
+        interpolator = ActionInterpolator(multiplier=cfg.interpolation_multiplier)
+        action_interval = interpolator.get_control_interval(cfg.fps)
+
+        while not shutdown_event.is_set():
+            start_time = time.perf_counter()
+
+            if interpolator.needs_new_action():
+                new_action = action_queue.get()
+                if new_action is not None:
+                    interpolator.add(new_action.cpu())
+
+            action = interpolator.get()
+            if action is not None:
+                action = action.cpu()
+                action_dict = {key: action[i].item() for i, key in enumerate(action_keys)}
+                action_processed = robot_action_processor((action_dict, None))
+                robot.send_action(action_processed)
+                action_count += 1
+
+            dt_s = time.perf_counter() - start_time
+            time.sleep(max(0, (action_interval - dt_s) - 0.001))
+
+        logger.info(f"[ACTOR] Actor thread shutting down. Total actions executed: {action_count}")
+    except Exception as e:
+        logger.error(f"[ACTOR] Fatal exception in actor_control thread: {e}")
+        logger.error(traceback.format_exc())
+        sys.exit(1)
+
+
+def _apply_torch_compile(policy, cfg: RTCDemoConfig):
+    """Apply torch.compile to the policy's predict_action_chunk method.
+
+    Args:
+        policy: Policy instance to compile
+        cfg: Configuration containing torch compile settings
+
+    Returns:
+        Policy with compiled predict_action_chunk method
+    """
+
+    # PI models handle their own compilation
+    if policy.type == "pi05" or policy.type == "pi0":
+        return policy
+
+    try:
+        # Check if torch.compile is available (PyTorch 2.0+)
+        if not hasattr(torch, "compile"):
+            logger.warning(
+                f"torch.compile is not available. Requires PyTorch 2.0+. "
+                f"Current version: {torch.__version__}. Skipping compilation."
+            )
+            return policy
+
+        logger.info("Applying torch.compile to predict_action_chunk...")
+        logger.info(f"  Backend: {cfg.torch_compile_backend}")
+        logger.info(f"  Mode: {cfg.torch_compile_mode}")
+        logger.info(f"  Disable CUDA graphs: {cfg.torch_compile_disable_cudagraphs}")
+
+        # Compile the predict_action_chunk method
+        # - CUDA graphs disabled to prevent tensor aliasing from in-place ops (x_t += dt * v_t)
+        compile_kwargs = {
+            "backend": cfg.torch_compile_backend,
+            "mode": cfg.torch_compile_mode,
+        }
+
+        # Disable CUDA graphs if requested (prevents tensor aliasing issues)
+        if cfg.torch_compile_disable_cudagraphs:
+            compile_kwargs["options"] = {"triton.cudagraphs": False}
+
+        original_method = policy.predict_action_chunk
+        compiled_method = torch.compile(original_method, **compile_kwargs)
+        policy.predict_action_chunk = compiled_method
+        logger.info("✓ Successfully compiled predict_action_chunk")
+
+    except Exception as e:
+        logger.error(f"Failed to apply torch.compile: {e}")
+        logger.warning("Continuing without torch.compile")
+
+    return policy
+
+
+@parser.wrap()
+def demo_cli(cfg: RTCDemoConfig):
+    """Main entry point for RTC demo with draccus configuration."""
+
+    # Initialize logging
+    init_logging()
+
+    logger.info(f"Using device: {cfg.device}")
+
+    # Setup signal handler for graceful shutdown
+    signal_handler = ProcessSignalHandler(use_threads=True, display_pid=False)
+    shutdown_event = signal_handler.shutdown_event
+
+    policy = None
+    robot = None
+    get_actions_thread = None
+    actor_thread = None
+
+    policy_class = get_policy_class(cfg.policy.type)
+
+    # Load config and set compile_model for pi0/pi05 models
+    config = PreTrainedConfig.from_pretrained(cfg.policy.pretrained_path)
+
+    if cfg.policy.type == "pi05" or cfg.policy.type == "pi0":
+        config.compile_model = cfg.use_torch_compile
+
+    if config.use_peft:
+        from peft import PeftConfig, PeftModel
+
+        peft_pretrained_path = cfg.policy.pretrained_path
+        peft_config = PeftConfig.from_pretrained(peft_pretrained_path)
+
+        policy = policy_class.from_pretrained(
+            pretrained_name_or_path=peft_config.base_model_name_or_path, config=config
+        )
+        policy = PeftModel.from_pretrained(policy, peft_pretrained_path, config=peft_config)
+    else:
+        policy = policy_class.from_pretrained(cfg.policy.pretrained_path, config=config)
+
+    # Turn on RTC
+    policy.config.rtc_config = cfg.rtc
+
+    # Init RTC processort, as by default if RTC disabled in the config
+    # The processor won't be created
+    policy.init_rtc_processor()
+
+    assert policy.name in ["smolvla", "pi05", "pi0"], "Only smolvla, pi05, and pi0 are supported for RTC"
+
+    policy = policy.to(cfg.device)
+    policy.eval()
+
+    # Apply torch.compile to predict_action_chunk method if enabled
+    if cfg.use_torch_compile:
+        policy = _apply_torch_compile(policy, cfg)
+
+    # Create robot
+    logger.info(f"Initializing robot: {cfg.robot.type}")
+    robot = make_robot_from_config(cfg.robot)
+    robot.connect()
+    robot_wrapper = RobotWrapper(robot)
+
+    # Create robot observation processor
+    robot_observation_processor = make_default_robot_observation_processor()
+    robot_action_processor = make_default_robot_action_processor()
+
+    # Create action queue for communication between threads
+    action_queue = ActionQueue(cfg.rtc)
+
+    # Start chunk requester thread
+    get_actions_thread = Thread(
+        target=get_actions,
+        args=(policy, robot_wrapper, robot_observation_processor, action_queue, shutdown_event, cfg),
+        daemon=True,
+        name="GetActions",
+    )
+    get_actions_thread.start()
+    logger.info("Started get actions thread")
+
+    # Start action executor thread
+    actor_thread = Thread(
+        target=actor_control,
+        args=(robot_wrapper, robot_action_processor, action_queue, shutdown_event, cfg),
+        daemon=True,
+        name="Actor",
+    )
+    actor_thread.start()
+    logger.info("Started actor thread")
+
+    logger.info("Started stop by duration thread")
+
+    # Main thread monitors for duration or shutdown
+    logger.info(f"Running demo for {cfg.duration} seconds...")
+    start_time = time.time()
+
+    while not shutdown_event.is_set() and (time.time() - start_time) < cfg.duration:
+        time.sleep(10)
+
+        # Log queue status periodically
+        if int(time.time() - start_time) % 5 == 0:
+            logger.info(f"[MAIN] Action queue size: {action_queue.qsize()}")
+
+        if time.time() - start_time > cfg.duration:
+            break
+
+    logger.info("Demo duration reached or shutdown requested")
+
+    # Signal shutdown
+    shutdown_event.set()
+
+    # Wait for threads to finish
+    if get_actions_thread and get_actions_thread.is_alive():
+        logger.info("Waiting for chunk requester thread to finish...")
+        get_actions_thread.join()
+
+    if actor_thread and actor_thread.is_alive():
+        logger.info("Waiting for action executor thread to finish...")
+        actor_thread.join()
+
+    # Cleanup robot
+    if robot:
+        robot.disconnect()
+        logger.info("Robot disconnected")
+
+    logger.info("Cleanup completed")
+
+
+if __name__ == "__main__":
+    demo_cli()
+    logging.info("RTC demo finished")

examples/so100_to_so100_EE/evaluate.py

@@ -14,17 +14,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import logging
-import time
-
 from lerobot.cameras.opencv import OpenCVCameraConfig
-from lerobot.common.control_utils import init_keyboard_listener, predict_action
+from lerobot.common.control_utils import init_keyboard_listener
 from lerobot.configs import FeatureType, PolicyFeature
 from lerobot.datasets import LeRobotDataset, aggregate_pipeline_dataset_features, create_initial_features
 from lerobot.model.kinematics import RobotKinematics
 from lerobot.policies import make_pre_post_processors
 from lerobot.policies.act import ACTPolicy
-from lerobot.policies.utils import make_robot_action
 from lerobot.processor import (
     RobotProcessorPipeline,
     make_default_teleop_action_processor,
@@ -38,12 +34,11 @@ from lerobot.robots.so_follower.robot_kinematic_processor import (
     ForwardKinematicsJointsToEE,
     InverseKinematicsEEToJoints,
 )
+from lerobot.scripts.lerobot_record import record_loop
 from lerobot.types import RobotAction, RobotObservation
-from lerobot.utils.constants import ACTION, OBS_STR
-from lerobot.utils.feature_utils import build_dataset_frame, combine_feature_dicts
-from lerobot.utils.robot_utils import precise_sleep
+from lerobot.utils.feature_utils import combine_feature_dicts
 from lerobot.utils.utils import log_say
-from lerobot.utils.visualization_utils import init_rerun, log_rerun_data
+from lerobot.utils.visualization_utils import init_rerun
 
 NUM_EPISODES = 5
 FPS = 30
@@ -54,9 +49,6 @@ HF_DATASET_ID = "<hf_username>/<dataset_repo_id>"
 
 
 def main():
-    # NOTE: For production policy deployment, use `lerobot-rollout` CLI instead.
-    # This script provides a self-contained example for educational purposes.
-
     # Create the robot configuration & robot
     camera_config = {"front": OpenCVCameraConfig(index_or_path=0, width=640, height=480, fps=FPS)}
     robot_config = SO100FollowerConfig(
@@ -151,67 +143,43 @@ def main():
             raise ValueError("Robot is not connected!")
 
         print("Starting evaluate loop...")
-        control_interval = 1 / FPS
         episode_idx = 0
         for episode_idx in range(NUM_EPISODES):
             log_say(f"Running inference, recording eval episode {episode_idx + 1} of {NUM_EPISODES}")
 
-            # Inline evaluation loop: predict actions and send to robot
-            timestamp = 0
-            start_episode_t = time.perf_counter()
-            while timestamp < EPISODE_TIME_SEC:
-                start_loop_t = time.perf_counter()
-
-                if events["exit_early"]:
-                    events["exit_early"] = False
-                    break
-
-                # Get robot observation
-                obs = robot.get_observation()
-                obs_processed = robot_joints_to_ee_pose_processor(obs)
-                observation_frame = build_dataset_frame(dataset.features, obs_processed, prefix=OBS_STR)
-
-                # Predict action using the policy
-                action_tensor = predict_action(
-                    observation=observation_frame,
-                    policy=policy,
-                    device=policy.config.device,
-                    preprocessor=preprocessor,
-                    postprocessor=postprocessor,
-                    use_amp=policy.config.device.type == "cuda",
-                    task=TASK_DESCRIPTION,
-                    robot_type=robot.name,
-                )
-
-                # Convert policy output to robot action dict
-                action_values = make_robot_action(action_tensor, dataset.features)
-
-                # Process and send action to robot (EE -> joints via IK)
-                robot_action_to_send = robot_ee_to_joints_processor((action_values, obs))
-                robot.send_action(robot_action_to_send)
-
-                # Write to dataset
-                action_frame = build_dataset_frame(dataset.features, action_values, prefix=ACTION)
-                frame = {**observation_frame, **action_frame, "task": TASK_DESCRIPTION}
-                dataset.add_frame(frame)
-
-                log_rerun_data(observation=obs_processed, action=action_values)
-
-                dt_s = time.perf_counter() - start_loop_t
-                sleep_time_s = control_interval - dt_s
-                if sleep_time_s < 0:
-                    logging.warning(
-                        f"Evaluate loop is running slower ({1 / dt_s:.1f} Hz) than the target FPS ({FPS} Hz)."
-                    )
-                precise_sleep(max(sleep_time_s, 0.0))
-                timestamp = time.perf_counter() - start_episode_t
+            # Main record loop
+            record_loop(
+                robot=robot,
+                events=events,
+                fps=FPS,
+                policy=policy,
+                preprocessor=preprocessor,  # Pass the pre and post policy processors
+                postprocessor=postprocessor,
+                dataset=dataset,
+                control_time_s=EPISODE_TIME_SEC,
+                single_task=TASK_DESCRIPTION,
+                display_data=True,
+                teleop_action_processor=make_default_teleop_action_processor(),
+                robot_action_processor=robot_ee_to_joints_processor,
+                robot_observation_processor=robot_joints_to_ee_pose_processor,
+            )
 
             # Reset the environment if not stopping or re-recording
             if not events["stop_recording"] and (
                 (episode_idx < NUM_EPISODES - 1) or events["rerecord_episode"]
             ):
                 log_say("Reset the environment")
-                log_say("Waiting for environment reset, press right arrow key when ready...")
+                record_loop(
+                    robot=robot,
+                    events=events,
+                    fps=FPS,
+                    control_time_s=EPISODE_TIME_SEC,
+                    single_task=TASK_DESCRIPTION,
+                    display_data=True,
+                    teleop_action_processor=make_default_teleop_action_processor(),
+                    robot_action_processor=robot_ee_to_joints_processor,
+                    robot_observation_processor=robot_joints_to_ee_pose_processor,
+                )
 
             if events["rerecord_episode"]:
                 log_say("Re-record episode")
@@ -222,6 +190,7 @@ def main():
 
             # Save episode
             dataset.save_episode()
+            episode_idx += 1
     finally:
         # Clean up
         log_say("Stop recording")

examples/so100_to_so100_EE/record.py

@@ -62,20 +62,21 @@ def main():
     follower = SO100Follower(follower_config)
     leader = SO100Leader(leader_config)
 
-    # NOTE: It is highly recommended to use the urdf in the SO-ARM100 repo:
-    #   https://github.com/TheRobotStudio/SO-ARM100/blob/main/Simulation/SO101/so101_new_calib.urdf
+    # NOTE: It is highly recommended to use the urdf in the SO-ARM100 repo: https://github.com/TheRobotStudio/SO-ARM100/blob/main/Simulation/SO101/so101_new_calib.urdf
     follower_kinematics_solver = RobotKinematics(
         urdf_path="./SO101/so101_new_calib.urdf",
         target_frame_name="gripper_frame_link",
         joint_names=list(follower.bus.motors.keys()),
     )
+
+    # NOTE: It is highly recommended to use the urdf in the SO-ARM100 repo: https://github.com/TheRobotStudio/SO-ARM100/blob/main/Simulation/SO101/so101_new_calib.urdf
     leader_kinematics_solver = RobotKinematics(
         urdf_path="./SO101/so101_new_calib.urdf",
         target_frame_name="gripper_frame_link",
         joint_names=list(leader.bus.motors.keys()),
     )
 
-    # Build pipeline to convert follower joints to EE observation.
+    # Build pipeline to convert follower joints to EE observation
     follower_joints_to_ee = RobotProcessorPipeline[RobotObservation, RobotObservation](
         steps=[
             ForwardKinematicsJointsToEE(
@@ -86,7 +87,7 @@ def main():
         to_output=transition_to_observation,
     )
 
-    # Build pipeline to convert leader joints to EE action.
+    # Build pipeline to convert leader joints to EE action
     leader_joints_to_ee = RobotProcessorPipeline[tuple[RobotAction, RobotObservation], RobotAction](
         steps=[
             ForwardKinematicsJointsToEE(
@@ -97,9 +98,9 @@ def main():
         to_output=transition_to_robot_action,
     )
 
-    # Build pipeline to convert EE action to follower joints (with safety bounds).
+    # Build pipeline to convert EE action to follower joints
     ee_to_follower_joints = RobotProcessorPipeline[tuple[RobotAction, RobotObservation], RobotAction](
-        steps=[
+        [
             EEBoundsAndSafety(
                 end_effector_bounds={"min": [-1.0, -1.0, -1.0], "max": [1.0, 1.0, 1.0]},
                 max_ee_step_m=0.10,
@@ -114,12 +115,13 @@ def main():
         to_output=transition_to_robot_action,
     )
 
-    # Create the dataset, deriving features from the pipelines so the on-disk schema
-    # matches exactly what the pipelines produce at runtime.
+    # Create the dataset
     dataset = LeRobotDataset.create(
         repo_id=HF_REPO_ID,
         fps=FPS,
         features=combine_feature_dicts(
+            # Run the feature contract of the pipelines
+            # This tells you how the features would look like after the pipeline steps
             aggregate_pipeline_dataset_features(
                 pipeline=leader_joints_to_ee,
                 initial_features=create_initial_features(action=leader.action_features),
@@ -142,7 +144,7 @@ def main():
 
     # Initialize the keyboard listener and rerun visualization
     listener, events = init_keyboard_listener()
-    init_rerun(session_name="recording_so100_ee")
+    init_rerun(session_name="recording_phone")
 
     try:
         if not leader.is_connected or not follower.is_connected:
@@ -158,14 +160,14 @@ def main():
                 robot=follower,
                 events=events,
                 fps=FPS,
-                teleop_action_processor=leader_joints_to_ee,
-                robot_action_processor=ee_to_follower_joints,
-                robot_observation_processor=follower_joints_to_ee,
                 teleop=leader,
                 dataset=dataset,
                 control_time_s=EPISODE_TIME_SEC,
                 single_task=TASK_DESCRIPTION,
                 display_data=True,
+                teleop_action_processor=leader_joints_to_ee,
+                robot_action_processor=ee_to_follower_joints,
+                robot_observation_processor=follower_joints_to_ee,
             )
 
             # Reset the environment if not stopping or re-recording
@@ -177,13 +179,13 @@ def main():
                     robot=follower,
                     events=events,
                     fps=FPS,
-                    teleop_action_processor=leader_joints_to_ee,
-                    robot_action_processor=ee_to_follower_joints,
-                    robot_observation_processor=follower_joints_to_ee,
                     teleop=leader,
                     control_time_s=RESET_TIME_SEC,
                     single_task=TASK_DESCRIPTION,
                     display_data=True,
+                    teleop_action_processor=leader_joints_to_ee,
+                    robot_action_processor=ee_to_follower_joints,
+                    robot_observation_processor=follower_joints_to_ee,
                 )
 
             if events["rerecord_episode"]:

examples/so100_to_so100_EE/rollout.py

@@ -1,134 +0,0 @@
-# !/usr/bin/env python
-
-# Copyright 2025 The HuggingFace Inc. team. All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-"""Run a trained EE-space policy on SO100 without recording (base rollout).
-
-Uses the rollout engine's :class:`BaseStrategy` (autonomous execution,
-no dataset) with :class:`SyncInferenceConfig` (inline policy call per
-control tick).  The custom observation/action processors convert between
-joint space (robot hardware) and end-effector space (policy I/O) via
-forward/inverse kinematics.
-"""
-
-from lerobot.cameras.opencv import OpenCVCameraConfig
-from lerobot.configs import PreTrainedConfig
-from lerobot.model.kinematics import RobotKinematics
-from lerobot.processor import (
-    RobotProcessorPipeline,
-    observation_to_transition,
-    robot_action_observation_to_transition,
-    transition_to_observation,
-    transition_to_robot_action,
-)
-from lerobot.robots.so_follower import SO100Follower, SO100FollowerConfig
-from lerobot.robots.so_follower.robot_kinematic_processor import (
-    ForwardKinematicsJointsToEE,
-    InverseKinematicsEEToJoints,
-)
-from lerobot.rollout import BaseStrategyConfig, RolloutConfig, build_rollout_context
-from lerobot.rollout.inference import SyncInferenceConfig
-from lerobot.rollout.strategies import BaseStrategy
-from lerobot.types import RobotAction, RobotObservation
-from lerobot.utils.process import ProcessSignalHandler
-from lerobot.utils.utils import init_logging
-
-FPS = 30
-DURATION_SEC = 60
-TASK_DESCRIPTION = "My task description"
-HF_MODEL_ID = "<hf_username>/<model_repo_id>"
-
-
-def main():
-    init_logging()
-
-    # Robot configuration — the rollout engine will connect it inside build_rollout_context.
-    camera_config = {"front": OpenCVCameraConfig(index_or_path=0, width=640, height=480, fps=FPS)}
-    robot_config = SO100FollowerConfig(
-        port="/dev/tty.usbmodem5A460814411",
-        id="my_awesome_follower_arm",
-        cameras=camera_config,
-        use_degrees=True,
-    )
-
-    # Kinematic solver: we need the motor-name list, so peek at the robot once.
-    # (The rollout engine owns the connected instance; we only use this for introspection.)
-    temp_robot = SO100Follower(robot_config)
-    motor_names = list(temp_robot.bus.motors.keys())
-
-    # NOTE: It is highly recommended to use the urdf in the SO-ARM100 repo:
-    #   https://github.com/TheRobotStudio/SO-ARM100/blob/main/Simulation/SO101/so101_new_calib.urdf
-    kinematics_solver = RobotKinematics(
-        urdf_path="./SO101/so101_new_calib.urdf",
-        target_frame_name="gripper_frame_link",
-        joint_names=motor_names,
-    )
-
-    # Joint-space observation → EE-space observation (consumed by the policy).
-    robot_joints_to_ee_pose_processor = RobotProcessorPipeline[RobotObservation, RobotObservation](
-        steps=[ForwardKinematicsJointsToEE(kinematics=kinematics_solver, motor_names=motor_names)],
-        to_transition=observation_to_transition,
-        to_output=transition_to_observation,
-    )
-
-    # EE-space action (produced by the policy) → joint-space action (sent to robot).
-    robot_ee_to_joints_processor = RobotProcessorPipeline[tuple[RobotAction, RobotObservation], RobotAction](
-        steps=[
-            InverseKinematicsEEToJoints(
-                kinematics=kinematics_solver,
-                motor_names=motor_names,
-                initial_guess_current_joints=True,
-            ),
-        ],
-        to_transition=robot_action_observation_to_transition,
-        to_output=transition_to_robot_action,
-    )
-
-    # Policy config (full model is loaded inside build_rollout_context).
-    policy_config = PreTrainedConfig.from_pretrained(HF_MODEL_ID)
-    policy_config.pretrained_path = HF_MODEL_ID
-
-    cfg = RolloutConfig(
-        robot=robot_config,
-        policy=policy_config,
-        strategy=BaseStrategyConfig(),
-        inference=SyncInferenceConfig(),
-        fps=FPS,
-        duration=DURATION_SEC,
-        task=TASK_DESCRIPTION,
-    )
-
-    signal_handler = ProcessSignalHandler(use_threads=True)
-
-    # Pass the EE kinematic processors via kwargs; the defaults (identity) would
-    # otherwise skip the joint↔EE conversion and the policy would receive the
-    # wrong observation/action space.
-    ctx = build_rollout_context(
-        cfg,
-        signal_handler.shutdown_event,
-        robot_action_processor=robot_ee_to_joints_processor,
-        robot_observation_processor=robot_joints_to_ee_pose_processor,
-    )
-
-    strategy = BaseStrategy(cfg.strategy)
-    try:
-        strategy.setup(ctx)
-        strategy.run(ctx)
-    finally:
-        strategy.teardown(ctx)
-
-
-if __name__ == "__main__":
-    main()

examples/tutorial/rl/hilserl_example.py

@@ -10,7 +10,7 @@ from lerobot.datasets import LeRobotDataset
 from lerobot.envs.configs import HILSerlProcessorConfig, HILSerlRobotEnvConfig
 from lerobot.policies import SACConfig
 from lerobot.policies.sac.modeling_sac import SACPolicy
-from lerobot.rewards.classifier.modeling_classifier import Classifier
+from lerobot.policies.sac.reward_model.modeling_classifier import Classifier
 from lerobot.rl.buffer import ReplayBuffer
 from lerobot.rl.gym_manipulator import make_robot_env
 from lerobot.robots.so_follower import SO100FollowerConfig

examples/tutorial/rl/reward_classifier_example.py

@@ -1,7 +1,7 @@
 import torch
 
 from lerobot.datasets import LeRobotDataset
-from lerobot.rewards import RewardClassifierConfig, make_reward_model, make_reward_pre_post_processors
+from lerobot.policies import RewardClassifierConfig, make_policy, make_pre_post_processors
 
 
 def main():
@@ -22,10 +22,10 @@ def main():
         model_name="microsoft/resnet-18",
     )
 
-    # Make reward model, preprocessor, and optimizer
-    reward_model = make_reward_model(config, dataset_stats=dataset.meta.stats)
-    optimizer = config.get_optimizer_preset().build(reward_model.parameters())
-    preprocessor, _ = make_reward_pre_post_processors(config, dataset_stats=dataset.meta.stats)
+    # Make policy, preprocessor, and optimizer
+    policy = make_policy(config, ds_meta=dataset.meta)
+    optimizer = config.get_optimizer_preset().build(policy.parameters())
+    preprocessor, _ = make_pre_post_processors(policy_cfg=config, dataset_stats=dataset.meta.stats)
 
     classifier_id = "<user>/reward_classifier_hil_serl_example"
 
@@ -42,7 +42,7 @@ def main():
             batch = preprocessor(batch)
 
             # Forward pass
-            loss, output_dict = reward_model.forward(batch)
+            loss, output_dict = policy.forward(batch)
 
             # Backward pass and optimization
             optimizer.zero_grad()
@@ -58,8 +58,8 @@ def main():
 
     print("Training finished!")
 
-    # You can now save the trained reward model.
-    reward_model.push_to_hub(classifier_id)
+    # You can now save the trained policy.
+    policy.push_to_hub(classifier_id)
 
 
 if __name__ == "__main__":

pyproject.toml

@@ -95,7 +95,7 @@ dependencies = [
 
 # ── Feature-scoped extras ──────────────────────────────────
 dataset = [
-    "datasets>=4.0.0,<5.0.0",
+    "datasets>=4.7.0,<5.0.0",
     "pandas>=2.0.0,<3.0.0", # NOTE: Transitive dependency of datasets
     "pyarrow>=21.0.0,<30.0.0", # NOTE: Transitive dependency of datasets
     "lerobot[av-dep]",
@@ -200,6 +200,15 @@ hilserl = ["lerobot[transformers-dep]", "gym-hil>=0.1.13,<0.2.0", "lerobot[grpci
 async = ["lerobot[grpcio-dep]", "lerobot[matplotlib-dep]"]
 peft = ["lerobot[transformers-dep]", "lerobot[peft-dep]"]
 
+# Annotation pipeline (lerobot-annotate). datatrove is mandatory; vllm is
+# the preferred backend on Linux, with a transformers fallback elsewhere.
+annotations = [
+    "lerobot[dataset]",
+    "lerobot[transformers-dep]",
+    "datatrove>=0.4.0,<2.0.0",
+    "vllm>=0.6.0,<1.0.0; sys_platform == 'linux'",
+]
+
 # Development
 dev = ["pre-commit>=3.7.0,<5.0.0", "debugpy>=1.8.1,<1.9.0", "lerobot[grpcio-dep]", "grpcio-tools==1.73.1", "mypy>=1.19.1", "ruff>=0.14.1", "lerobot[notebook]"]
 notebook = ["jupyter>=1.0.0,<2.0.0", "ipykernel>=6.0.0,<7.0.0"]
@@ -289,7 +298,7 @@ lerobot-find-joint-limits="lerobot.scripts.lerobot_find_joint_limits:main"
 lerobot-imgtransform-viz="lerobot.scripts.lerobot_imgtransform_viz:main"
 lerobot-edit-dataset="lerobot.scripts.lerobot_edit_dataset:main"
 lerobot-setup-can="lerobot.scripts.lerobot_setup_can:main"
-lerobot-rollout="lerobot.scripts.lerobot_rollout:main"
+lerobot-annotate="lerobot.scripts.lerobot_annotate:main"
 
 # ---------------- Tool Configurations ----------------
 [tool.setuptools.package-data]

src/lerobot/annotations/__init__.py

@@ -0,0 +1,15 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.

src/lerobot/annotations/steerable_pipeline/__init__.py

@@ -0,0 +1,36 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Steerable annotation pipeline producing ``language_persistent`` and
+``language_events`` columns for LeRobot datasets.
+
+The pipeline is decomposed into three independently runnable modules whose
+outputs are staged per-episode before a final parquet rewrite:
+
+- :mod:`.modules.plan_subtasks_memory` (Module 1) — persistent styles
+- :mod:`.modules.interjections_and_speech` (Module 2) — event styles + speech
+- :mod:`.modules.general_vqa` (Module 3) — event-style VQA pairs
+"""
+
+from .config import AnnotationPipelineConfig
+from .validator import StagingValidator, ValidationReport
+from .writer import LanguageColumnsWriter
+
+__all__ = [
+    "AnnotationPipelineConfig",
+    "LanguageColumnsWriter",
+    "StagingValidator",
+    "ValidationReport",
+]

src/lerobot/annotations/steerable_pipeline/config.py

@@ -0,0 +1,204 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from pathlib import Path
+
+
+@dataclass
+class Module1Config:
+    """Module 1 hyperparameters: plan + subtasks + memory.
+
+    Subtask decomposition sees the **whole episode** as one Qwen-VL video
+    block — no keyframe stride or count: the model handles temporal pooling
+    itself and decides where to cut. ``max_video_frames`` only caps the
+    number of frames packed into the video block (a model-capacity bound,
+    not an annotation-logic knob).
+    """
+
+    enabled: bool = True
+    frames_per_second: float = 1.0
+    """Sample one image-frame per ``1/fps`` seconds across the episode for
+    Module 1's subtask-decomposition prompt. ``1.0`` = 1 fps. Capped by
+    ``max_video_frames`` to avoid blowing up the request payload."""
+    max_video_frames: int = 128
+    """Hard cap on the number of frames Module 1 sends. With ``fps=1`` and
+    a 30 s episode this yields 30 frames. Bumped from 32 since each frame
+    is small (~30-100 KB PNG when base64'd)."""
+    min_subtask_seconds: float = 1.5
+    plan_max_steps: int = 8
+    use_video_url: bool = False
+    """When True (and backend supports it, e.g. ``openai``), Module 1
+    sends a ``video_url`` content block pointing at the episode's mp4
+    file instead of pre-decoded frames. Lets the server sample frames at
+    its own ``fps`` — no in-process conv3d cost. The video file is
+    extracted as a per-episode subclip to ``staging/.video_clips/`` so
+    the model sees only this episode's frames."""
+    use_video_url_fps: float = 1.0
+    """Frame-rate hint to send to the server (mm_processor_kwargs.fps).
+    Only used when ``use_video_url=True``. ``1.0`` = sample 1 frame per
+    second, which is plenty for subtask-boundary detection on most
+    manipulation episodes."""
+
+
+@dataclass
+class Module2Config:
+    """Module 2 hyperparameters: interjections + paired speech."""
+
+    enabled: bool = True
+    max_interjections_per_episode: int = 1
+    interjection_min_t: float = 2.0
+
+
+@dataclass
+class Module3Config:
+    """Module 3 hyperparameters: general VQA."""
+
+    enabled: bool = True
+    vqa_emission_hz: float = 1.0
+    K: int = 3
+    question_types: tuple[str, ...] = ("bbox", "keypoint", "count", "attribute", "spatial")
+
+
+@dataclass
+class VlmConfig:
+    """Shared Qwen-VL client configuration."""
+
+    backend: str = "openai"
+    """One of ``vllm``, ``transformers``, ``openai``, or ``stub`` (tests only).
+
+    Default ``openai`` talks to a local OpenAI-compatible server (vllm /
+    transformers) which the CLI auto-spawns when ``auto_serve=True``."""
+    model_id: str = "Qwen/Qwen2.5-VL-7B-Instruct"
+    api_base: str = "http://localhost:8000/v1"
+    """Base URL for the ``openai`` backend."""
+    api_key: str = "EMPTY"
+    """API key for the ``openai`` backend; ``EMPTY`` works for local servers."""
+    auto_serve: bool = True
+    """When True with ``backend=openai``, the CLI probes ``api_base``
+    first; if no server answers, it spawns one (default:
+    ``transformers serve``), waits for it to be ready, runs the
+    pipeline, and tears it down on exit. Default ``True`` so a single
+    ``lerobot-annotate`` call can drive the whole flow. Set to ``False``
+    if you want to fail fast when no server is reachable (e.g. you're
+    pointing at a remote endpoint that should already be up)."""
+    serve_port: int = 8000
+    """Port the auto-spawned server binds to. Sets ``api_base`` automatically."""
+    serve_command: str | None = None
+    """Override the auto-serve command (full shell command). When ``None``,
+    we run ``transformers serve <model_id> --port <serve_port> --continuous-batching``.
+
+    When ``parallel_servers > 1``, the literal ``{port}`` placeholder in
+    this command (if present) is substituted per-replica."""
+    parallel_servers: int = 1
+    """When >1, spawn this many independent inference servers (each pinned
+    to one GPU via ``CUDA_VISIBLE_DEVICES`` and listening on
+    ``serve_port + i``) and round-robin client requests across them.
+    Useful when DP/TP NCCL setup is broken on the node — single-GPU
+    replicas don't need cross-GPU communication."""
+    client_concurrency: int = 16
+    """Maximum number of in-flight chat requests the client issues in
+    parallel. vllm batches them internally for free, so bumping this
+    typically gives big throughput wins on a single TP=1 server. Set to
+    ``1`` for strict serial calls."""
+    serve_ready_timeout_s: float = 600.0
+    """Max seconds to wait for the server to start serving requests."""
+    max_new_tokens: int = 512
+    temperature: float = 0.2
+    json_mode: bool = True
+    batch_size: int = 4
+    tensor_parallel_size: int = 1
+    gpu_memory_utilization: float = 0.9
+    """Fraction of GPU memory vllm allocates for weights + KV cache.
+    Lower (e.g. 0.7) when the vision encoder needs cuDNN workspace, or to
+    avoid CUDNN_STATUS_NOT_INITIALIZED on tight VRAM (30B BF16 on 80 GB)."""
+    max_model_len: int | None = None
+    """Cap context length. ``None`` keeps the model's default; on H100 80 GB
+    a 30B BF16 model often needs ``max_model_len=8192`` or smaller to leave
+    room for KV cache."""
+    trust_remote_code: bool = False
+    """Pass ``trust_remote_code`` to HF auto-classes. Default ``False`` —
+    only enable for models that actually ship custom code in their repo
+    (rare for first-class VL releases). On Qwen3-VL it triggers an
+    std::bad_alloc post-load even though the official transformers class
+    is sufficient, so leaving this off is safest."""
+    camera_key: str | None = None
+    """Override the camera stream used for keyframe attachment. ``None`` picks
+    the first ``observation.images.*`` key the dataset declares."""
+
+
+@dataclass
+class ExecutorConfig:
+    """Executor selection and SLURM hyperparameters."""
+
+    auto_threshold: int = 32
+    force_local: bool = False
+    slurm_partition: str | None = None
+    slurm_gpus: int = 1
+    slurm_time: str = "06:00:00"
+    workers: int = 1
+    episode_parallelism: int = 16
+    """Number of episodes processed concurrently within each module phase.
+    Each in-flight episode sends 3–5 dependent VLM calls; bumping this is
+    how you actually saturate ``parallel_servers`` and ``client_concurrency``
+    — without it, the executor loops one episode at a time and the
+    inference servers sit ~90% idle. Set to ``1`` for strict serial
+    execution."""
+
+
+@dataclass
+class AnnotationPipelineConfig:
+    """Top-level config for ``lerobot-annotate``.
+
+    Mirrors the structure of :class:`lerobot.configs.train.TrainPipelineConfig`:
+    a draccus-parsed dataclass that contains nested per-module sub-configs and
+    leaves the dataset, executor, and VLM choices independently knobbable.
+
+    Output is always in-place: the writer rewrites ``data/chunk-*/file-*.parquet``
+    in place. Multiple revisions of the same dataset live in separate copies.
+    """
+
+    repo_id: str | None = None
+    root: Path | None = None
+
+    staging_dir: Path | None = None
+    """If unset, defaults to ``<root>/.annotate_staging/``."""
+
+    seed: int = 1729
+
+    module_1: Module1Config = field(default_factory=Module1Config)
+    module_2: Module2Config = field(default_factory=Module2Config)
+    module_3: Module3Config = field(default_factory=Module3Config)
+
+    vlm: VlmConfig = field(default_factory=VlmConfig)
+    executor: ExecutorConfig = field(default_factory=ExecutorConfig)
+
+    skip_validation: bool = False
+    only_episodes: tuple[int, ...] | None = None
+
+    push_to_hub: str | None = None
+    """If set, after the pipeline completes, upload the annotated dataset
+    root to the Hugging Face Hub as a dataset repo with this id (e.g.
+    ``pepijn/super_poulain_steerable``). Creates the repo if missing."""
+    push_private: bool = False
+    """When ``push_to_hub`` is set, create the repo as private."""
+    push_commit_message: str | None = None
+    """Override the commit message used for the hub upload."""
+
+    def resolved_staging_dir(self, root: Path) -> Path:
+        return self.staging_dir if self.staging_dir is not None else root / ".annotate_staging"

src/lerobot/annotations/steerable_pipeline/executor.py

@@ -0,0 +1,207 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Executor selection: local vs SLURM via datatrove.
+
+The executor plans **four phases** with the dependency order from the plan:
+
+    phase 1: Module 1 (plan + subtasks + memory)
+    phase 2: Module 2 (interjections + speech)
+    phase 3: Module 1 plan-update pass — re-runs plan emission at every
+             interjection timestamp produced by phase 2
+    phase 4: Module 3 (VQA)
+    phase 5: validator
+    phase 6: writer
+
+Phase 3 is why ``executor.py`` documents the dependency: Module 1 must be
+re-entered after Module 2 to refresh ``plan`` rows at interjection times.
+"""
+
+from __future__ import annotations
+
+import logging
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any
+
+from .config import AnnotationPipelineConfig, ExecutorConfig
+from .reader import EpisodeRecord, iter_episodes
+from .staging import EpisodeStaging
+from .validator import StagingValidator
+from .writer import LanguageColumnsWriter
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass
+class PhaseResult:
+    """Summary of one pipeline phase across all episodes."""
+
+    name: str
+    episodes_processed: int
+    episodes_skipped: int
+
+
+@dataclass
+class PipelineRunSummary:
+    """Aggregated result returned by :meth:`Executor.run`."""
+
+    phases: list[PhaseResult]
+    written_paths: list[Path]
+    validation_report: Any  # ValidationReport, kept Any to avoid import cycle
+
+
+def select_executor_class(num_episodes: int, config: ExecutorConfig) -> str:
+    """Return ``"local"`` or ``"slurm"`` based on the threshold.
+
+    The plan's "executor selection threshold" lives in
+    :class:`ExecutorConfig.auto_threshold`. ``force_local`` always wins.
+    """
+    if config.force_local:
+        return "local"
+    return "local" if num_episodes <= config.auto_threshold else "slurm"
+
+
+@dataclass
+class Executor:
+    """Run all four phases over a dataset root.
+
+    The executor is intentionally framework-agnostic: by default it runs the
+    phases inline (suitable for tests, small datasets, and the CLI's
+    ``--force-local`` mode). It will optionally hand off to datatrove's
+    :class:`LocalPipelineExecutor` or :class:`SlurmPipelineExecutor` when those
+    are installed and the dataset is large enough to benefit from them.
+
+    Tests construct the executor directly with stub modules.
+    """
+
+    config: AnnotationPipelineConfig
+    module_1: Any  # PlanSubtasksMemoryModule
+    module_2: Any  # InterjectionsAndSpeechModule
+    module_3: Any  # GeneralVqaModule
+    writer: LanguageColumnsWriter
+    validator: StagingValidator
+
+    def run(self, root: Path) -> PipelineRunSummary:
+        records = list(iter_episodes(root, only_episodes=self.config.only_episodes))
+        n = len(records)
+        if n == 0:
+            raise ValueError(f"No episodes found under {root}/data/")
+
+        executor_kind = select_executor_class(n, self.config.executor)
+        print(f"[annotate] {n} episodes total; executor={executor_kind}", flush=True)
+
+        staging_dir = self.config.resolved_staging_dir(root)
+        staging_dir.mkdir(parents=True, exist_ok=True)
+
+        phases: list[PhaseResult] = []
+
+        # Phase 1: Module 1 (plan + subtasks + memory)
+        phases.append(self._run_module_phase("module_1", records, staging_dir, self.module_1))
+        # Phase 2: Module 2 (interjections + speech)
+        phases.append(self._run_module_phase("module_2", records, staging_dir, self.module_2))
+        # Phase 3: Module 1 plan-update pass at interjection timestamps.
+        phases.append(self._run_plan_update_phase(records, staging_dir))
+        # Phase 4: Module 3 (VQA)
+        phases.append(self._run_module_phase("module_3", records, staging_dir, self.module_3))
+
+        print("[annotate] running validator...", flush=True)
+        report = self.validator.validate(records, staging_dir)
+        if not report.ok and not self.config.skip_validation:
+            raise RuntimeError(f"Staging validation failed: {report.summary()}")
+        print(f"[annotate] validator: {report.summary()}", flush=True)
+
+        print(f"[annotate] writing parquet shards into {root}/data/...", flush=True)
+        written = self.writer.write_all(records, staging_dir, root)
+        print(f"[annotate] wrote {len(written)} shard(s); pipeline complete", flush=True)
+        return PipelineRunSummary(phases=phases, written_paths=written, validation_report=report)
+
+    def _run_module_phase(
+        self,
+        name: str,
+        records: list[EpisodeRecord],
+        staging_dir: Path,
+        module: Any,
+    ) -> PhaseResult:
+        import time as _time  # noqa: PLC0415
+        from concurrent.futures import ThreadPoolExecutor, as_completed  # noqa: PLC0415
+
+        if not module.enabled:
+            print(f"[annotate] phase={name} skipped (module disabled)", flush=True)
+            return PhaseResult(name=name, episodes_processed=0, episodes_skipped=len(records))
+        n = len(records)
+        parallelism = max(1, min(self.config.executor.episode_parallelism, n))
+        print(
+            f"[annotate] phase={name} starting on {n} episode(s) "
+            f"(parallelism={parallelism})",
+            flush=True,
+        )
+        t0 = _time.time()
+
+        def _do(idx_record: tuple[int, EpisodeRecord]) -> tuple[int, int, float]:
+            i, record = idx_record
+            ep_start = _time.time()
+            staging = EpisodeStaging(staging_dir, record.episode_index)
+            module.run_episode(record, staging)
+            return i, record.episode_index, _time.time() - ep_start
+
+        processed = 0
+        if parallelism == 1:
+            for i, record in enumerate(records, 1):
+                _, ep_idx, elapsed = _do((i, record))
+                processed += 1
+                print(
+                    f"[annotate]   {name} episode {i}/{n} "
+                    f"(idx={ep_idx}) done in {elapsed:.1f}s",
+                    flush=True,
+                )
+        else:
+            with ThreadPoolExecutor(max_workers=parallelism) as pool:
+                futures = [pool.submit(_do, (i, r)) for i, r in enumerate(records, 1)]
+                for fut in as_completed(futures):
+                    i, ep_idx, elapsed = fut.result()
+                    processed += 1
+                    print(
+                        f"[annotate]   {name} episode {processed}/{n} "
+                        f"(idx={ep_idx}, submit_order={i}) done in {elapsed:.1f}s",
+                        flush=True,
+                    )
+        total = _time.time() - t0
+        print(f"[annotate] phase={name} complete: {processed}/{n} in {total:.1f}s", flush=True)
+        return PhaseResult(name=name, episodes_processed=processed, episodes_skipped=0)
+
+    def _run_plan_update_phase(  # noqa: PLR0915
+        self, records: list[EpisodeRecord], staging_dir: Path
+    ) -> PhaseResult:
+        """Re-emit ``plan`` rows at each interjection timestamp from Module 2.
+
+        Module 1 owns the prompt; Module 2 produced the timestamps. This phase
+        therefore calls back into Module 1 with the interjection timestamps so
+        Module 1's existing prompt path is reused.
+        """
+        if not self.module_1.enabled or not self.module_2.enabled:
+            return PhaseResult(
+                name="module_1_plan_update", episodes_processed=0, episodes_skipped=len(records)
+            )
+        processed = 0
+        for record in records:
+            staging = EpisodeStaging(staging_dir, record.episode_index)
+            interjection_times = [
+                row["timestamp"] for row in staging.read("module_2") if row.get("style") == "interjection"
+            ]
+            if interjection_times:
+                self.module_1.run_plan_updates(record, staging, interjection_times)
+                processed += 1
+        return PhaseResult(name="module_1_plan_update", episodes_processed=processed, episodes_skipped=0)

src/lerobot/annotations/steerable_pipeline/frames.py

@@ -0,0 +1,264 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Keyframe extraction for the annotation pipeline.
+
+Modules attach decoded camera frames to their VLM prompts so the model can
+ground subtask decomposition, interjection scenarios, and VQA in actual
+visual content. The pipeline shares one provider across modules and one
+episode at a time, with a small per-episode cache so multiple modules
+querying the same timestamp pay decode cost once.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from pathlib import Path
+from typing import Any, Protocol
+
+from .reader import EpisodeRecord
+
+
+class FrameProvider(Protocol):
+    """Decodes camera frames at episode-relative timestamps."""
+
+    def frames_at(self, record: EpisodeRecord, timestamps: list[float]) -> list[Any]:
+        """Return one PIL.Image per timestamp; empty list if no camera available."""
+
+    def video_for_episode(self, record: EpisodeRecord, max_frames: int) -> list[Any]:
+        """Return up to ``max_frames`` PIL images covering the whole episode.
+
+        Sampling is uniform across the episode duration. The returned list is
+        intended to be passed as one ``{"type":"video", "video":<list>}``
+        block to a Qwen-VL-compatible model that pools temporally itself.
+        Empty list if no camera available.
+        """
+
+
+@dataclass
+class _NullProvider:
+    """No-op provider used when the dataset has no video keys or in tests."""
+
+    def frames_at(self, record: EpisodeRecord, timestamps: list[float]) -> list[Any]:
+        return []
+
+    def video_for_episode(self, record: EpisodeRecord, max_frames: int) -> list[Any]:
+        return []
+
+
+def null_provider() -> FrameProvider:
+    return _NullProvider()
+
+
+@dataclass
+class VideoFrameProvider:
+    """Decodes frames from the dataset's first ``observation.images.*`` stream.
+
+    The first camera key is used unconditionally — Module 1/2/3 prompts care
+    about *what is happening*, not which camera angle the model sees, so a
+    single canonical viewpoint is enough. Override ``camera_key`` if you
+    want a specific stream.
+
+    Caches up to ``cache_size`` decoded frames per process to keep
+    co-timestamped Module 2 + Module 1 plan-update calls cheap.
+    """
+
+    root: Path
+    camera_key: str | None = None
+    tolerance_s: float = 1e-2
+    cache_size: int = 256
+    _meta: Any = field(default=None, init=False, repr=False)
+    _cache: dict = field(default_factory=dict, init=False, repr=False)
+
+    def __post_init__(self) -> None:
+        from lerobot.datasets.dataset_metadata import LeRobotDatasetMetadata  # noqa: PLC0415
+
+        self._meta = LeRobotDatasetMetadata(repo_id="local", root=self.root)
+        if self.camera_key is None:
+            keys = self._meta.video_keys
+            self.camera_key = keys[0] if keys else None
+
+    def frames_at(self, record: EpisodeRecord, timestamps: list[float]) -> list[Any]:
+        if not timestamps or self.camera_key is None:
+            return []
+
+        out: list[Any] = []
+        misses: list[float] = []
+        miss_indices: list[int] = []
+        for i, ts in enumerate(timestamps):
+            key = (record.episode_index, round(float(ts), 6))
+            cached = self._cache.get(key)
+            if cached is not None:
+                out.append(cached)
+            else:
+                out.append(None)
+                misses.append(float(ts))
+                miss_indices.append(i)
+
+        if misses:
+            decoded = self._decode(record.episode_index, misses)
+            # decoder may return fewer frames than requested when some
+            # timestamps fall outside the video; pair what we have and
+            # leave the rest as None to be filtered below.
+            for i, img in zip(miss_indices, decoded):
+                out[i] = img
+                key = (record.episode_index, round(float(timestamps[i]), 6))
+                if len(self._cache) >= self.cache_size:
+                    self._cache.pop(next(iter(self._cache)))
+                self._cache[key] = img
+        # filter out any None left over from decode failures
+        return [img for img in out if img is not None]
+
+    def _decode(self, episode_index: int, timestamps: list[float]) -> list[Any]:
+        import os as _os  # noqa: PLC0415
+
+        from PIL import Image  # noqa: PLC0415
+
+        from lerobot.datasets.video_utils import decode_video_frames  # noqa: PLC0415
+
+        ep = self._meta.episodes[episode_index]
+        from_timestamp = ep[f"videos/{self.camera_key}/from_timestamp"]
+        shifted = [from_timestamp + ts for ts in timestamps]
+        video_path = self.root / self._meta.get_video_file_path(episode_index, self.camera_key)
+        # ``torchcodec`` import currently bad-allocs on cu128/torch-2.8 in
+        # some environments; default to ``pyav`` (always available via
+        # the ``av`` package) and let users override with
+        # LEROBOT_VIDEO_BACKEND=torchcodec when their stack supports it.
+        backend = _os.environ.get("LEROBOT_VIDEO_BACKEND", "pyav")
+        try:
+            frames = decode_video_frames(
+                video_path,
+                shifted,
+                self.tolerance_s,
+                backend=backend,
+                return_uint8=True,
+            )
+        except Exception:
+            return []
+        # frames: [N, C, H, W] uint8, RGB
+        out: list[Any] = []
+        arr = frames.cpu().numpy() if hasattr(frames, "cpu") else frames
+        for i in range(arr.shape[0]):
+            chw = arr[i]
+            hwc = chw.transpose(1, 2, 0)
+            out.append(Image.fromarray(hwc, mode="RGB"))
+        return out
+
+    def video_for_episode(self, record: EpisodeRecord, max_frames: int) -> list[Any]:
+        """Return up to ``max_frames`` images uniformly sampled across the episode.
+
+        The whole episode duration is covered; the model picks subtask
+        boundaries from the temporal pooling it does internally.
+        """
+        if max_frames <= 0 or self.camera_key is None or not record.frame_timestamps:
+            return []
+        n_frames = min(max_frames, len(record.frame_timestamps))
+        if n_frames == len(record.frame_timestamps):
+            timestamps = list(record.frame_timestamps)
+        else:
+            t0 = record.frame_timestamps[0]
+            t_last = record.frame_timestamps[-1]
+            if t_last <= t0:
+                timestamps = [float(t0)] * n_frames
+            else:
+                step = (t_last - t0) / (n_frames - 1) if n_frames > 1 else 0.0
+                timestamps = [float(t0 + i * step) for i in range(n_frames)]
+        return self.frames_at(record, timestamps)
+
+
+def make_frame_provider(root: Path, camera_key: str | None = None) -> FrameProvider:
+    """Build a :class:`VideoFrameProvider` if videos are present, else null."""
+    try:
+        provider = VideoFrameProvider(root=root, camera_key=camera_key)
+    except Exception:
+        return null_provider()
+    if provider.camera_key is None:
+        return null_provider()
+    return provider
+
+
+def to_image_blocks(images: list[Any]) -> list[dict[str, Any]]:
+    """Convert PIL images to Qwen-VL-compatible content blocks."""
+    return [{"type": "image", "image": img} for img in images]
+
+
+def to_video_block(images: list[Any]) -> list[dict[str, Any]]:
+    """Wrap a list of PIL images as one Qwen-VL video block.
+
+    Returns ``[]`` when the list is empty, so the caller can splat the result
+    into a content array without a separate emptiness check.
+    """
+    if not images:
+        return []
+    return [{"type": "video", "video": list(images)}]
+
+
+def to_video_url_block(url: str | None, fps: float = 2.0) -> list[dict[str, Any]]:
+    """Wrap a video file URL as one ``video_url`` block.
+
+    Used by the ``openai`` backend (transformers serve / vllm serve /
+    ktransformers serve), where the server handles frame sampling.
+    Returns ``[]`` when ``url`` is ``None`` so the caller can splat.
+    """
+    if not url:
+        return []
+    return [{"type": "video_url", "video_url": {"url": url}, "fps": fps}]
+
+
+def episode_clip_path(
+    record: EpisodeRecord,
+    provider: "VideoFrameProvider",
+    cache_dir: Path,
+) -> Path | None:
+    """Extract the episode's subclip to ``cache_dir/ep_{idx:06d}.mp4``.
+
+    Returns ``None`` if the dataset has no video tracks. Skips re-extract
+    when the cached clip already exists. Uses ``ffmpeg`` via subprocess
+    with stream-copy where possible (no re-encode) for speed.
+    """
+    import subprocess  # noqa: PLC0415
+
+    if provider.camera_key is None:
+        return None
+    cache_dir.mkdir(parents=True, exist_ok=True)
+    out_path = cache_dir / f"ep_{record.episode_index:06d}.mp4"
+    if out_path.exists() and out_path.stat().st_size > 0:
+        return out_path
+    ep = provider._meta.episodes[record.episode_index]
+    from_timestamp = float(ep[f"videos/{provider.camera_key}/from_timestamp"])
+    to_timestamp = float(ep[f"videos/{provider.camera_key}/to_timestamp"])
+    src = provider.root / provider._meta.get_video_file_path(
+        record.episode_index, provider.camera_key
+    )
+    cmd = [
+        "ffmpeg",
+        "-y",
+        "-loglevel",
+        "error",
+        "-ss",
+        f"{from_timestamp:.3f}",
+        "-to",
+        f"{to_timestamp:.3f}",
+        "-i",
+        str(src),
+        "-c",
+        "copy",
+        str(out_path),
+    ]
+    try:
+        subprocess.run(cmd, check=True, timeout=120)
+    except (subprocess.CalledProcessError, subprocess.TimeoutExpired, FileNotFoundError):
+        return None
+    return out_path if out_path.exists() and out_path.stat().st_size > 0 else None

src/lerobot/annotations/steerable_pipeline/modules/__init__.py

@@ -0,0 +1,25 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from .general_vqa import GeneralVqaModule
+from .interjections_and_speech import InterjectionsAndSpeechModule
+from .plan_subtasks_memory import PlanSubtasksMemoryModule
+
+__all__ = [
+    "GeneralVqaModule",
+    "InterjectionsAndSpeechModule",
+    "PlanSubtasksMemoryModule",
+]

src/lerobot/annotations/steerable_pipeline/modules/general_vqa.py

@@ -0,0 +1,173 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Module 3: general VQA at a timed cadence.
+
+Anchors ``K`` (question, answer) pairs to ``K`` consecutive frames per
+emission so each frame gets at most one ``(vqa, user)`` and one
+``(vqa, assistant)`` pair — keeps the resolver contract scalar.
+
+Question types covered (per the plan's Module 3 table): bbox, keypoint,
+count, attribute, spatial. The assistant's ``content`` is a JSON string
+whose schema depends on the question type. Malformed JSON triggers one
+retry inside :meth:`VlmClient.generate_json`.
+"""
+
+from __future__ import annotations
+
+import json
+import random
+from collections.abc import Sequence
+from dataclasses import dataclass, field
+from typing import Any
+
+from ..config import Module3Config
+from ..frames import FrameProvider, null_provider, to_image_blocks
+from ..prompts import load as load_prompt
+from ..reader import EpisodeRecord
+from ..staging import EpisodeStaging
+from ..validator import classify_vqa_answer
+from ..vlm_client import VlmClient
+
+
+def _emission_anchor_indices(frame_timestamps: Sequence[float], hz: float, k: int) -> list[int]:
+    """Return the relative frame indices to anchor VQA emissions to.
+
+    For each emission tick (every ``1/hz`` seconds), we anchor ``k``
+    consecutive frames starting at the tick. Ticks fall on the nearest
+    available source frame timestamp.
+    """
+    if hz <= 0 or k <= 0 or not frame_timestamps:
+        return []
+    t0 = frame_timestamps[0]
+    t_last = frame_timestamps[-1]
+    period = 1.0 / hz
+    indices: list[int] = []
+    t = t0
+    while t <= t_last + 1e-9:
+        # find the index of the nearest frame to t
+        nearest_i = min(range(len(frame_timestamps)), key=lambda i: abs(frame_timestamps[i] - t))
+        for offset in range(k):
+            j = nearest_i + offset
+            if j >= len(frame_timestamps):
+                break
+            if not indices or indices[-1] != j:
+                indices.append(j)
+        t += period
+    # dedupe while preserving order
+    seen: set[int] = set()
+    deduped: list[int] = []
+    for i in indices:
+        if i in seen:
+            continue
+        seen.add(i)
+        deduped.append(i)
+    return deduped
+
+
+@dataclass
+class GeneralVqaModule:
+    """Emit grounded VQA pairs at a timed cadence."""
+
+    vlm: VlmClient
+    config: Module3Config
+    seed: int = 1729
+    frame_provider: FrameProvider = field(default_factory=null_provider)
+
+    @property
+    def enabled(self) -> bool:
+        return self.config.enabled
+
+    def run_episode(self, record: EpisodeRecord, staging: EpisodeStaging) -> None:
+        if not record.frame_timestamps:
+            staging.write("module_3", [])
+            return
+        rng = random.Random(f"{self.seed}:{record.episode_index}:vqa")
+        anchor_idx = _emission_anchor_indices(
+            record.frame_timestamps, self.config.vqa_emission_hz, self.config.K
+        )
+        # Build all messages first, then issue them as a single batched
+        # generate_json call so the client can fan them out concurrently.
+        per_call: list[tuple[float, str, list[dict[str, Any]]]] = []
+        for idx in anchor_idx:
+            ts = float(record.frame_timestamps[idx])
+            qtype = rng.choice(self.config.question_types)
+            messages = self._build_messages(record, qtype, ts)
+            per_call.append((ts, qtype, messages))
+
+        if not per_call:
+            staging.write("module_3", [])
+            return
+
+        results = self.vlm.generate_json([m for _, _, m in per_call])
+
+        rows: list[dict[str, Any]] = []
+        for (ts, _qtype, _messages), result in zip(per_call, results):
+            qa = self._postprocess(result)
+            if qa is None:
+                continue
+            question, answer = qa
+            rows.append(
+                {
+                    "role": "user",
+                    "content": question,
+                    "style": "vqa",
+                    "timestamp": ts,
+                    "tool_calls": None,
+                }
+            )
+            rows.append(
+                {
+                    "role": "assistant",
+                    "content": json.dumps(answer, sort_keys=True),
+                    "style": "vqa",
+                    "timestamp": ts,
+                    "tool_calls": None,
+                }
+            )
+        staging.write("module_3", rows)
+
+    def _build_messages(
+        self, record: EpisodeRecord, question_type: str, frame_timestamp: float
+    ) -> list[dict[str, Any]]:
+        prompt = load_prompt("module_3_vqa").format(
+            episode_task=record.episode_task,
+            question_type=question_type,
+        )
+        images = self.frame_provider.frames_at(record, [frame_timestamp])
+        content = [*to_image_blocks(images), {"type": "text", "text": prompt}]
+        return [{"role": "user", "content": content}]
+
+    def _postprocess(self, result: Any) -> tuple[str, dict[str, Any]] | None:
+        if not isinstance(result, dict):
+            return None
+        question = result.get("question")
+        answer = result.get("answer")
+        if not isinstance(question, str) or not question.strip():
+            return None
+        if not isinstance(answer, dict):
+            return None
+        # The validator will enforce shape; here we just sanity-check that the
+        # answer matches *some* known shape so we can drop garbage early.
+        if classify_vqa_answer(answer) is None:
+            return None
+        return question.strip(), answer
+
+    def _generate_one(
+        self, record: EpisodeRecord, question_type: str, frame_timestamp: float
+    ) -> tuple[str, dict[str, Any]] | None:
+        messages = self._build_messages(record, question_type, frame_timestamp)
+        result = self.vlm.generate_json([messages])[0]
+        return self._postprocess(result)

src/lerobot/annotations/steerable_pipeline/modules/interjections_and_speech.py

@@ -0,0 +1,133 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Module 2: interjections + paired speech (EVENT styles + speech atoms).
+
+Two sub-passes:
+
+1. At ``t=0``, emit ONLY a speech tool-call atom (acknowledgement of the
+   canonical task). No interjection row — the canonical task is already the
+   user utterance from ``meta/tasks.parquet``.
+
+2. For mid-episode interruptions, emit a co-timestamped pair:
+       {role:user, style:interjection, content:<text>}
+       speech atom (role:assistant, style:None, tool_calls=[say(...)])
+   Both rows go in ``language_events`` at the same timestamp.
+
+Module 1's :meth:`run_plan_updates` reuses Module 2's interjection
+timestamps to refresh the ``plan`` row at the same instant.
+"""
+
+from __future__ import annotations
+
+import random
+from collections.abc import Sequence
+from dataclasses import dataclass, field
+from typing import Any
+
+from ..config import Module2Config
+from ..frames import FrameProvider, null_provider, to_image_blocks
+from ..prompts import load as load_prompt
+from ..reader import EpisodeRecord
+from ..staging import EpisodeStaging
+from ..vlm_client import VlmClient
+from ..writer import speech_atom
+
+
+def _snap_to_frame(t: float, frame_timestamps: Sequence[float]) -> float:
+    if not frame_timestamps:
+        return float(t)
+    return float(min(frame_timestamps, key=lambda f: abs(f - t)))
+
+
+@dataclass
+class InterjectionsAndSpeechModule:
+    """Generate task-start speech and mid-episode interjection/speech pairs."""
+
+    vlm: VlmClient
+    config: Module2Config
+    seed: int = 1729
+    frame_provider: FrameProvider = field(default_factory=null_provider)
+
+    @property
+    def enabled(self) -> bool:
+        return self.config.enabled
+
+    def run_episode(self, record: EpisodeRecord, staging: EpisodeStaging) -> None:
+        rows: list[dict[str, Any]] = []
+        if record.frame_timestamps:
+            t0 = float(record.frame_timestamps[0])
+            initial = self._initial_speech(record)
+            if initial:
+                rows.append(speech_atom(t0, initial))
+        rows.extend(self._mid_episode_interjections(record))
+        staging.write("module_2", rows)
+
+    def _initial_speech(self, record: EpisodeRecord) -> str | None:
+        prompt = load_prompt("module_2_initial_speech").format(
+            episode_task=record.episode_task,
+        )
+        messages = [{"role": "user", "content": [{"type": "text", "text": prompt}]}]
+        result = self.vlm.generate_json([messages])[0]
+        if isinstance(result, dict) and isinstance(result.get("text"), str):
+            text = result["text"].strip()
+            if text:
+                return text
+        return None
+
+    def _mid_episode_interjections(self, record: EpisodeRecord) -> list[dict[str, Any]]:
+        if self.config.max_interjections_per_episode <= 0:
+            return []
+        # Deterministic per-episode RNG so reruns are stable across SLURM jobs.
+        rng = random.Random(f"{self.seed}:{record.episode_index}:interjection")
+        candidate_ts = [t for t in record.frame_timestamps if t >= self.config.interjection_min_t]
+        if not candidate_ts:
+            return []
+        n = min(self.config.max_interjections_per_episode, len(candidate_ts) // 4)
+        if n <= 0:
+            return []
+        chosen = sorted(rng.sample(candidate_ts, n))
+        out: list[dict[str, Any]] = []
+        for t in chosen:
+            t_snap = _snap_to_frame(t, record.frame_timestamps)
+            current_subtask = record.episode_task
+            prompt = load_prompt("module_2_interjection").format(
+                episode_task=record.episode_task,
+                current_subtask=current_subtask,
+                timestamp=t_snap,
+            )
+            images = self.frame_provider.frames_at(record, [t_snap])
+            content = [*to_image_blocks(images), {"type": "text", "text": prompt}]
+            messages = [{"role": "user", "content": content}]
+            result = self.vlm.generate_json([messages])[0]
+            if not isinstance(result, dict):
+                continue
+            interjection_text = result.get("interjection")
+            speech_text = result.get("speech")
+            if not isinstance(interjection_text, str) or not interjection_text.strip():
+                continue
+            if not isinstance(speech_text, str) or not speech_text.strip():
+                continue
+            out.append(
+                {
+                    "role": "user",
+                    "content": interjection_text.strip(),
+                    "style": "interjection",
+                    "timestamp": t_snap,
+                    "tool_calls": None,
+                }
+            )
+            out.append(speech_atom(t_snap, speech_text.strip()))
+        return out

src/lerobot/annotations/steerable_pipeline/modules/plan_subtasks_memory.py

@@ -0,0 +1,252 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Module 1: subtask decomposition + plan + memory (PERSISTENT styles)."""
+
+from __future__ import annotations
+
+from collections.abc import Sequence
+from dataclasses import dataclass, field
+from typing import Any
+
+from pathlib import Path
+
+from ..config import Module1Config
+from ..frames import (
+    FrameProvider,
+    VideoFrameProvider,
+    episode_clip_path,
+    null_provider,
+    to_video_block,
+    to_video_url_block,
+)
+from ..prompts import load as load_prompt
+from ..reader import EpisodeRecord
+from ..staging import EpisodeStaging
+from ..vlm_client import VlmClient
+
+
+def _snap_to_frame(t: float, frame_timestamps: Sequence[float]) -> float:
+    """Snap an arbitrary float to the nearest exact source frame timestamp."""
+    if not frame_timestamps:
+        return float(t)
+    nearest = min(frame_timestamps, key=lambda f: abs(f - t))
+    return float(nearest)
+
+
+@dataclass
+class PlanSubtasksMemoryModule:
+    """Generate subtask spans, plan, and memory rows.
+
+    All output is persistent (lives in ``language_persistent``):
+
+    - ``subtask`` rows: one per span, stamped at the span's *start* timestamp
+      (snapped to an exact frame).
+    - ``plan`` rows: emitted at ``t=0``; refreshed at every interjection
+      timestamp via :meth:`run_plan_updates` (called by the executor after
+      Module 2 completes).
+    - ``memory`` rows: emitted at each subtask boundary (= subtask start
+      timestamp from the second subtask onward).
+    """
+
+    vlm: VlmClient
+    config: Module1Config
+    frame_provider: FrameProvider = field(default_factory=null_provider)
+
+    @property
+    def enabled(self) -> bool:
+        return self.config.enabled
+
+    def run_episode(self, record: EpisodeRecord, staging: EpisodeStaging) -> None:
+        rows: list[dict[str, Any]] = []
+        subtask_spans = self._generate_subtasks(record)
+        # subtask rows
+        for span in subtask_spans:
+            rows.append(
+                {
+                    "role": "assistant",
+                    "content": span["text"],
+                    "style": "subtask",
+                    "timestamp": _snap_to_frame(span["start"], record.frame_timestamps),
+                    "tool_calls": None,
+                }
+            )
+        # plan row at t=0
+        plan_text = self._generate_plan(record, subtask_spans)
+        if plan_text is not None:
+            t0 = record.frame_timestamps[0] if record.frame_timestamps else 0.0
+            rows.append(
+                {
+                    "role": "assistant",
+                    "content": plan_text,
+                    "style": "plan",
+                    "timestamp": float(t0),
+                    "tool_calls": None,
+                }
+            )
+        # memory rows at every subtask boundary except the very first start
+        prior_memory = ""
+        for i, span in enumerate(subtask_spans[1:], start=1):
+            completed = subtask_spans[i - 1]["text"]
+            remaining = [s["text"] for s in subtask_spans[i:]]
+            mem_text = self._generate_memory(record, prior_memory, completed, remaining)
+            if mem_text:
+                ts = _snap_to_frame(span["start"], record.frame_timestamps)
+                rows.append(
+                    {
+                        "role": "assistant",
+                        "content": mem_text,
+                        "style": "memory",
+                        "timestamp": ts,
+                        "tool_calls": None,
+                    }
+                )
+                prior_memory = mem_text
+        staging.write("module_1", rows)
+
+    def run_plan_updates(
+        self,
+        record: EpisodeRecord,
+        staging: EpisodeStaging,
+        interjection_times: Sequence[float],
+    ) -> None:
+        """Append additional ``plan`` rows at every interjection timestamp."""
+        existing = staging.read("module_1")
+        spans = self._reconstruct_subtasks_from_rows(existing)
+        new_rows = list(existing)
+        for raw_t in interjection_times:
+            t = _snap_to_frame(raw_t, record.frame_timestamps)
+            plan_text = self._generate_plan(record, spans, refresh_t=t)
+            if plan_text is not None:
+                new_rows.append(
+                    {
+                        "role": "assistant",
+                        "content": plan_text,
+                        "style": "plan",
+                        "timestamp": t,
+                        "tool_calls": None,
+                    }
+                )
+        staging.write("module_1", new_rows)
+
+    @staticmethod
+    def _reconstruct_subtasks_from_rows(rows: Sequence[dict[str, Any]]) -> list[dict[str, Any]]:
+        out = []
+        last_t: float | None = None
+        for row in sorted(
+            (r for r in rows if r.get("style") == "subtask"),
+            key=lambda r: float(r["timestamp"]),
+        ):
+            t = float(row["timestamp"])
+            if last_t is not None:
+                out[-1]["end"] = t
+            out.append({"text": row.get("content") or "", "start": t, "end": t})
+            last_t = t
+        return out
+
+    def _generate_subtasks(self, record: EpisodeRecord) -> list[dict[str, Any]]:
+        if record.row_count == 0 or not record.frame_timestamps:
+            return []
+        episode_duration = record.frame_timestamps[-1] - record.frame_timestamps[0]
+        prompt = load_prompt("module_1_subtasks").format(
+            episode_task=record.episode_task,
+            min_subtask_seconds=self.config.min_subtask_seconds,
+            max_steps=self.config.plan_max_steps,
+            episode_duration=f"{episode_duration:.3f}",
+        )
+        if self.config.use_video_url and isinstance(self.frame_provider, VideoFrameProvider):
+            cache_dir = Path(self.frame_provider.root) / ".annotate_staging" / ".video_clips"
+            clip = episode_clip_path(record, self.frame_provider, cache_dir)
+            video_block = (
+                to_video_url_block(f"file://{clip}", fps=self.config.use_video_url_fps)
+                if clip is not None
+                else []
+            )
+        else:
+            target_count = max(
+                1,
+                int(round(episode_duration * self.config.frames_per_second)),
+            )
+            target_count = min(target_count, self.config.max_video_frames)
+            video_frames = self.frame_provider.video_for_episode(record, target_count)
+            video_block = to_video_block(video_frames)
+        content = [*video_block, {"type": "text", "text": prompt}]
+        messages = [{"role": "user", "content": content}]
+        result = self.vlm.generate_json([messages])[0]
+        spans = result.get("subtasks") if isinstance(result, dict) else None
+        if not spans:
+            return []
+        # clamp to [t0, t_last] and sort
+        t0 = record.frame_timestamps[0]
+        t_last = record.frame_timestamps[-1]
+        cleaned: list[dict[str, Any]] = []
+        for span in spans:
+            try:
+                start = float(span["start"])
+                end = float(span["end"])
+                text = str(span["text"]).strip()
+            except (KeyError, ValueError, TypeError):
+                continue
+            start = max(t0, min(start, t_last))
+            end = max(t0, min(end, t_last))
+            if end < start:
+                start, end = end, start
+            if not text:
+                continue
+            cleaned.append({"text": text, "start": start, "end": end})
+        cleaned.sort(key=lambda s: s["start"])
+        return cleaned
+
+    def _generate_plan(
+        self,
+        record: EpisodeRecord,
+        subtask_spans: Sequence[dict[str, Any]],
+        *,
+        refresh_t: float | None = None,
+    ) -> str | None:
+        if not subtask_spans:
+            return None
+        subtasks_text = "\n".join(f"- {s['text']}" for s in subtask_spans)
+        prompt = load_prompt("module_1_plan").format(
+            episode_task=record.episode_task,
+            subtasks_text=subtasks_text,
+            plan_max_steps=self.config.plan_max_steps,
+        )
+        if refresh_t is not None:
+            prompt += f"\n\n(This is a plan refresh after a user interjection at t={refresh_t:.2f}s.)\n"
+        messages = [{"role": "user", "content": [{"type": "text", "text": prompt}]}]
+        result = self.vlm.generate_json([messages])[0]
+        if isinstance(result, dict) and isinstance(result.get("plan"), str):
+            return result["plan"].strip()
+        return None
+
+    def _generate_memory(
+        self,
+        record: EpisodeRecord,
+        prior_memory: str,
+        completed: str,
+        remaining: Sequence[str],
+    ) -> str:
+        prompt = load_prompt("module_1_memory").format(
+            episode_task=record.episode_task,
+            prior_memory=prior_memory or "(none)",
+            completed_subtask=completed,
+            remaining_subtasks=", ".join(remaining) if remaining else "(none)",
+        )
+        messages = [{"role": "user", "content": [{"type": "text", "text": prompt}]}]
+        result = self.vlm.generate_json([messages])[0]
+        if isinstance(result, dict) and isinstance(result.get("memory"), str):
+            return result["memory"].strip()
+        return ""

src/lerobot/annotations/steerable_pipeline/prompts/__init__.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Prompt templates loaded as plain text.
+
+One file per use site. Templates use ``str.format(**vars)`` substitution; we
+intentionally avoid jinja2 here so the templates remain inspectable in
+plain editors and roundtrip cleanly through ``ruff format``.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+_DIR = Path(__file__).parent
+
+
+def load(name: str) -> str:
+    """Read prompt template ``name.txt`` from the ``prompts/`` directory."""
+    path = _DIR / f"{name}.txt"
+    return path.read_text(encoding="utf-8")

src/lerobot/annotations/steerable_pipeline/prompts/module_1_memory.txt

@@ -0,0 +1,25 @@
+You are updating the robot's compressed semantic memory at the boundary of
+a completed subtask.
+
+Reference (verbatim from MEM, Torne 2026):
+"Remove or compress information in the language memory whenever
+appropriate. Keep ONLY the minimal set of relevant information for future
+task execution. Specific object attributes (colors, precise quantities of
+each item) get discarded when their details won't affect subsequent
+actions. Functional outcomes (where items went, how many) are preserved."
+
+Concrete example from MEM:
+  Before: "I put a light green bowl, a dark blue bowl and a bright yellow
+           bowl into the top right cabinet"
+  After:  "I placed three bowls in the top right cabinet"
+
+Episode task: "{episode_task}"
+Previous memory: {prior_memory}
+Just-completed subtask: "{completed_subtask}"
+Remaining subtasks (for relevance judgement only): {remaining_subtasks}
+
+Update the memory. Drop irrelevant detail. Compress completed steps.
+Keep WHAT happened, drop HOW. Shorter is better.
+
+Output strictly valid JSON:
+  {{ "memory": "<one or two short sentences>" }}

src/lerobot/annotations/steerable_pipeline/prompts/module_1_plan.txt

@@ -0,0 +1,18 @@
+You are the high-level planner for a robot demonstrating: "{episode_task}".
+
+Given the subtask decomposition below, write a concise hierarchical PLAN
+the robot should follow. Format the plan as a numbered list, one line per
+high-level step. The plan describes the full task; subtasks are the atomic
+skills used to execute it.
+
+Subtasks for context:
+{subtasks_text}
+
+Authoring rules:
+- 3 to {plan_max_steps} steps.
+- Each step describes one logical chunk of the task, not one motion.
+- Steps must be in execution order.
+- Plain prose, no JSON, no markdown headers.
+
+Output strictly valid JSON:
+  {{ "plan": "1. ...\n2. ...\n3. ..." }}

src/lerobot/annotations/steerable_pipeline/prompts/module_1_subtasks.txt

@@ -0,0 +1,33 @@
+You are labeling a teleoperated robot demonstration.
+
+The user originally asked: "{episode_task}"
+
+You are shown the entire demonstration as a single video. Watch the
+whole clip, then segment it into a list of consecutive atomic subtasks
+the robot performs.
+
+Authoring rules — based on Hi Robot (Shi 2025) atom granularity and
+Pi0.7 (Physical Intelligence 2025) "how, not what" detail:
+
+- Each subtask is one atomic skill the low-level policy can execute,
+  e.g. "pick up one piece of lettuce", "place the bowl into the box",
+  "move the right arm to the left".
+- Capture HOW the subtask is performed, not only WHAT — e.g. prefer
+  "grasp the handle of the sponge with the left hand" to "pick up the
+  sponge".
+- Subtasks are non-overlapping and cover the full episode in order.
+  Choose the cut points yourself based on what you see in the video
+  (gripper open/close events, contact, regrasps, transitions).
+- Each subtask spans at least {min_subtask_seconds} seconds.
+- Do not exceed {max_steps} subtasks total.
+- Every subtask's [start_time, end_time] must lie within
+  [0.0, {episode_duration}] seconds.
+
+Output strictly valid JSON of shape:
+
+  {{
+    "subtasks": [
+      {{"text": "<how-not-what>", "start": <float>, "end": <float>}},
+      ...
+    ]
+  }}

src/lerobot/annotations/steerable_pipeline/prompts/module_2_initial_speech.txt

@@ -0,0 +1,10 @@
+The user just asked the robot: "{episode_task}".
+
+Generate a short verbal acknowledgement the robot would speak back before
+beginning the task. Style: confident, friendly, single short sentence.
+
+Examples (Hi Robot, Shi 2025): "Sure, I won't put cheese on it.",
+"OK, starting with the sponge.", "Got it.".
+
+Output strictly valid JSON:
+  {{ "text": "<the spoken acknowledgement>" }}

src/lerobot/annotations/steerable_pipeline/prompts/module_2_interjection.txt

@@ -0,0 +1,27 @@
+You are simulating a user mid-episode interruption for a robot doing:
+"{episode_task}".
+
+Synthesize ONE realistic interruption the user might say at this moment in
+the demonstration, plus the robot's verbal acknowledgement.
+
+Context (Hi Robot, Shi 2025) — interjections fall into one of these
+scenario types:
+- negative task: "actually skip X"
+- situated correction: "that's not trash"
+- specific constraint: "use less salt"
+- preference: "could you also do Y"
+
+Interruption rules:
+- Must be plausible given the current subtask context.
+- Must change the plan in a non-trivial way (a new constraint, skipped
+  step, or correction).
+- One sentence each.
+
+Current subtask context: {current_subtask}
+Time into episode: {timestamp:.2f}s
+
+Output strictly valid JSON:
+  {{
+    "interjection": "<single sentence the user says>",
+    "speech":       "<single sentence the robot speaks back>"
+  }}

src/lerobot/annotations/steerable_pipeline/prompts/module_3_vqa.txt

@@ -0,0 +1,32 @@
+You are generating a frame-grounded visual question/answer pair for
+chain-of-thought training. Reference: ECoT (Zawalski 2024) and Steerable
+Policies — both train policies on grounded features such as bounding box
+pixel coordinates, keypoints, counts, attributes, and spatial relations.
+
+The frame shows a robot working on: "{episode_task}".
+
+Question types and the EXACT answer JSON shape required for each:
+
+  bbox       => {{"detections": [{{"label": "<obj>", "bbox_format": "xyxy",
+                                    "bbox": [x1, y1, x2, y2]}}, ...]}}
+                bbox is in pixel coordinates (x_min, y_min, x_max, y_max).
+                ECoT example: "a white cup [124, 25, 176, 113]".
+
+  keypoint   => {{"label": "<point>", "point_format": "xy",
+                  "point": [x, y]}}
+
+  count      => {{"label": "<obj>", "count": <int>,
+                  "note": "<optional short note>"}}
+
+  attribute  => {{"label": "<obj>", "attribute": "<color|shape|state|...>",
+                  "value": "<observed value>"}}
+
+  spatial    => {{"subject": "<obj>", "relation": "<left_of|right_of|on|in|"
+                  "above|below|near>", "object": "<obj>"}}
+
+Generate a question of type "{question_type}". Output strictly valid JSON:
+
+  {{
+    "question": "<short, frame-grounded question>",
+    "answer":   <object whose shape matches the schema above>
+  }}

src/lerobot/annotations/steerable_pipeline/reader.py

@@ -0,0 +1,219 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Datatrove-shaped reader.
+
+The reader walks ``data/chunk-*/file-*.parquet`` and yields one record per
+episode containing:
+
+- ``episode_index``: int
+- ``frame_timestamps``: tuple[float, ...]
+- ``frame_indices``: tuple[int, ...]
+- ``episode_task``: str (canonical task from ``meta/tasks.parquet``)
+- ``data_path``: pathlib.Path of the source parquet shard
+- ``frames_df``: pandas.DataFrame slice for the episode (only loaded on demand)
+
+This shape lets each module operate per-episode without loading all parquet
+rows into memory at once. It deliberately does not depend on datatrove —
+datatrove integration wraps this generator inside a ``PipelineStep`` in
+:mod:`.executor`.
+"""
+
+from __future__ import annotations
+
+from collections.abc import Iterator
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any
+
+import pyarrow.parquet as pq
+
+from lerobot.datasets.utils import DEFAULT_TASKS_PATH
+
+
+@dataclass
+class EpisodeRecord:
+    """Per-episode record yielded by the reader."""
+
+    episode_index: int
+    episode_task: str
+    frame_timestamps: tuple[float, ...]
+    frame_indices: tuple[int, ...]
+    data_path: Path
+    row_offset: int  # row offset within the parquet file where this episode starts
+    row_count: int  # number of rows for this episode
+
+    def frames_df(self):  # type: ignore[no-untyped-def]
+        """Lazy-load the pandas slice for this episode."""
+        import pandas as pd  # noqa: PLC0415  - deferred for optional dataset extra
+
+        table = pq.read_table(self.data_path)
+        df: pd.DataFrame = table.to_pandas()
+        slice_ = df.iloc[self.row_offset : self.row_offset + self.row_count].reset_index(drop=True)
+        return slice_
+
+
+def _load_tasks_lookup(root: Path) -> dict[int, str]:
+    tasks_path = root / DEFAULT_TASKS_PATH
+    if not tasks_path.exists():
+        return {}
+    table = pq.read_table(tasks_path)
+    cols = {name: table.column(name).to_pylist() for name in table.column_names}
+    if "task_index" in cols and "task" in cols:
+        return dict(zip(cols["task_index"], cols["task"], strict=True))
+    raise ValueError(f"meta/tasks.parquet at {tasks_path} missing 'task_index' or 'task'")
+
+
+def iter_episodes(root: Path, *, only_episodes: tuple[int, ...] | None = None) -> Iterator[EpisodeRecord]:
+    """Yield :class:`EpisodeRecord` for every episode under ``root/data/``.
+
+    Episodes are yielded in ascending ``episode_index`` order. The reader does
+    not assume a specific chunk/file layout: it scans every ``*.parquet``
+    under ``data/`` and groups by ``episode_index``.
+    """
+    tasks = _load_tasks_lookup(root)
+    data_dir = root / "data"
+    parquet_files = sorted(data_dir.rglob("*.parquet"))
+
+    only_set = set(only_episodes) if only_episodes is not None else None
+
+    for path in parquet_files:
+        yield from _iter_one_path(path, tasks, only_set)
+
+
+def _iter_one_path(path: Path, tasks: dict[int, str], only_set: set[int] | None) -> Iterator[EpisodeRecord]:
+    table = pq.read_table(path)
+    names = table.column_names
+    if "episode_index" not in names:
+        return
+    episode_col = table.column("episode_index").to_pylist()
+    timestamp_col = (
+        table.column("timestamp").to_pylist() if "timestamp" in names else [0.0] * len(episode_col)
+    )
+    frame_col = (
+        table.column("frame_index").to_pylist() if "frame_index" in names else list(range(len(episode_col)))
+    )
+    task_col = table.column("task_index").to_pylist() if "task_index" in names else None
+
+    def _build(
+        ep: int,
+        start: int,
+        end: int,
+        task_idx: int | None,
+        ts_buf: list[float],
+        fi_buf: list[int],
+    ) -> EpisodeRecord | None:
+        if only_set is not None and ep not in only_set:
+            return None
+        task = tasks.get(task_idx, "") if task_idx is not None else ""
+        return EpisodeRecord(
+            episode_index=ep,
+            episode_task=task,
+            frame_timestamps=tuple(ts_buf),
+            frame_indices=tuple(fi_buf),
+            data_path=path,
+            row_offset=start,
+            row_count=end - start,
+        )
+
+    cur_ep: int | None = None
+    start_offset = 0
+    ts_buf: list[float] = []
+    fi_buf: list[int] = []
+    cur_task_idx: int | None = None
+
+    for i, ep in enumerate(episode_col):
+        if cur_ep is None:
+            cur_ep = ep
+            start_offset = i
+            ts_buf = [timestamp_col[i]]
+            fi_buf = [frame_col[i]]
+            cur_task_idx = task_col[i] if task_col is not None else None
+            continue
+        if ep != cur_ep:
+            rec = _build(cur_ep, start_offset, i, cur_task_idx, ts_buf, fi_buf)
+            if rec is not None:
+                yield rec
+            cur_ep = ep
+            start_offset = i
+            ts_buf = [timestamp_col[i]]
+            fi_buf = [frame_col[i]]
+            cur_task_idx = task_col[i] if task_col is not None else None
+        else:
+            ts_buf.append(timestamp_col[i])
+            fi_buf.append(frame_col[i])
+
+    if cur_ep is not None:
+        rec = _build(cur_ep, start_offset, len(episode_col), cur_task_idx, ts_buf, fi_buf)
+        if rec is not None:
+            yield rec
+
+
+def gather_data_paths(root: Path) -> list[Path]:
+    """Return every ``data/chunk-*/file-*.parquet`` path under ``root``."""
+    return sorted((root / "data").rglob("*.parquet"))
+
+
+def episode_offsets_per_path(path: Path) -> dict[int, tuple[int, int]]:
+    """Return ``{episode_index: (row_offset, row_count)}`` for one parquet."""
+    table = pq.read_table(path, columns=["episode_index"])
+    episode_col = table.column("episode_index").to_pylist()
+    out: dict[int, tuple[int, int]] = {}
+    cur_ep: int | None = None
+    start = 0
+    for i, ep in enumerate(episode_col):
+        if cur_ep is None:
+            cur_ep = ep
+            start = i
+            continue
+        if ep != cur_ep:
+            out[cur_ep] = (start, i - start)
+            cur_ep = ep
+            start = i
+    if cur_ep is not None:
+        out[cur_ep] = (start, len(episode_col) - start)
+    return out
+
+
+def keyframe_indices(record: EpisodeRecord, k: int) -> list[int]:
+    """Return ``k`` evenly spaced row indices into the episode (relative)."""
+    n = record.row_count
+    if k <= 0 or n == 0:
+        return []
+    if k >= n:
+        return list(range(n))
+    step = (n - 1) / (k - 1) if k > 1 else 0.0
+    return [int(round(i * step)) for i in range(k)] if k > 1 else [n // 2]
+
+
+def lookup_data_path(root: Path, episode_index: int) -> tuple[Path, int, int] | None:
+    """Find the parquet file containing ``episode_index`` and its slice bounds."""
+    for path in gather_data_paths(root):
+        offsets = episode_offsets_per_path(path)
+        if episode_index in offsets:
+            start, count = offsets[episode_index]
+            return path, start, count
+    return None
+
+
+def episode_frame_timestamps(root: Path, episode_index: int) -> tuple[Any, list[float]]:
+    """Return the parquet path and per-frame timestamps for ``episode_index``."""
+    found = lookup_data_path(root, episode_index)
+    if found is None:
+        raise ValueError(f"Episode {episode_index} not found under {root}/data/")
+    path, start, count = found
+    table = pq.read_table(path, columns=["timestamp"])
+    timestamps = table.column("timestamp").to_pylist()[start : start + count]
+    return path, [float(t) for t in timestamps]

src/lerobot/annotations/steerable_pipeline/staging.py

@@ -0,0 +1,98 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Per-episode staging.
+
+Each module writes its raw output as a JSONL file under
+``<staging_dir>/episode_{ep:06d}/<module>.jsonl``. The writer reads back this
+staging tree and partitions rows into the two language columns.
+
+JSONL is preferred over parquet here because the staging artifact is meant to
+be human-inspectable, easy to diff between prompt iterations, and trivially
+appended to. The final dataset format is parquet; staging is just an
+intermediate.
+"""
+
+from __future__ import annotations
+
+import json
+from collections.abc import Iterable, Iterator
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any
+
+ModuleName = str
+
+_MODULES: tuple[ModuleName, ...] = (
+    "module_1",
+    "module_2",
+    "module_3",
+)
+
+
+@dataclass
+class EpisodeStaging:
+    """Filesystem layout for a single episode's staged module outputs."""
+
+    root: Path
+    episode_index: int
+
+    @property
+    def episode_dir(self) -> Path:
+        return self.root / f"episode_{self.episode_index:06d}"
+
+    def path_for(self, module: ModuleName) -> Path:
+        if module not in _MODULES:
+            raise ValueError(f"Unknown module {module!r}; expected one of {_MODULES}")
+        return self.episode_dir / f"{module}.jsonl"
+
+    def write(self, module: ModuleName, rows: Iterable[dict[str, Any]]) -> Path:
+        path = self.path_for(module)
+        path.parent.mkdir(parents=True, exist_ok=True)
+        with path.open("w", encoding="utf-8") as f:
+            for row in rows:
+                f.write(json.dumps(row, ensure_ascii=False, sort_keys=True))
+                f.write("\n")
+        return path
+
+    def read(self, module: ModuleName) -> list[dict[str, Any]]:
+        path = self.path_for(module)
+        if not path.exists():
+            return []
+        out: list[dict[str, Any]] = []
+        with path.open(encoding="utf-8") as f:
+            for line in f:
+                line = line.strip()
+                if line:
+                    out.append(json.loads(line))
+        return out
+
+    def read_all(self) -> dict[ModuleName, list[dict[str, Any]]]:
+        return {m: self.read(m) for m in _MODULES}
+
+    def has(self, module: ModuleName) -> bool:
+        return self.path_for(module).exists()
+
+
+def iter_staged_episodes(root: Path) -> Iterator[int]:
+    """Yield episode indices for which any staging artifact exists."""
+    if not root.exists():
+        return
+    for child in sorted(root.iterdir()):
+        if child.is_dir() and child.name.startswith("episode_"):
+            try:
+                yield int(child.name.removeprefix("episode_"))
+            except ValueError:
+                continue

src/lerobot/annotations/steerable_pipeline/validator.py

@@ -0,0 +1,271 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Pre-write validation against staged outputs.
+
+Runs after Modules 1–3 have all written their per-episode artifacts but
+*before* the writer rewrites parquet shards. The validator never touches
+parquet; it only inspects the staging tree and the source frame timestamps
+exposed by :class:`EpisodeRecord`.
+
+Checks (per the plan's "Intermediate staging and validation" section):
+
+- exact timestamp alignment against source frame timestamps
+- no orphan speech / interjection pairs
+- plan / memory emission consistency (events have a paired persistent row)
+- VQA assistant ``content`` is valid JSON (one of bbox / keypoint / count /
+  attribute / spatial)
+- every row maps to its correct column under :func:`column_for_style`
+"""
+
+from __future__ import annotations
+
+import json
+import logging
+from collections.abc import Iterable, Sequence
+from dataclasses import dataclass, field
+from pathlib import Path
+from typing import Any
+
+from lerobot.datasets.language import (
+    LANGUAGE_EVENTS,
+    LANGUAGE_PERSISTENT,
+    column_for_style,
+)
+
+from .reader import EpisodeRecord
+from .staging import EpisodeStaging
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass
+class ValidationReport:
+    """Outcome of one validation pass across all episodes."""
+
+    errors: list[str] = field(default_factory=list)
+    warnings: list[str] = field(default_factory=list)
+    episodes_checked: int = 0
+
+    @property
+    def ok(self) -> bool:
+        return not self.errors
+
+    def add_error(self, message: str) -> None:
+        self.errors.append(message)
+
+    def add_warning(self, message: str) -> None:
+        self.warnings.append(message)
+
+    def summary(self) -> str:
+        return f"checked={self.episodes_checked} errors={len(self.errors)} warnings={len(self.warnings)}"
+
+
+VQA_ANSWER_SHAPES: dict[str, set[str]] = {
+    "bbox": {"detections"},
+    "keypoint": {"label", "point_format", "point"},
+    "count": {"label", "count"},
+    "attribute": {"label", "attribute", "value"},
+    "spatial": {"subject", "relation", "object"},
+}
+
+
+def classify_vqa_answer(payload: Any) -> str | None:
+    """Best-effort classification of a VQA answer payload to a question type."""
+    if not isinstance(payload, dict):
+        return None
+    keys = set(payload.keys())
+    for kind, required in VQA_ANSWER_SHAPES.items():
+        if required.issubset(keys):
+            return kind
+    return None
+
+
+@dataclass
+class StagingValidator:
+    """Walks the staging tree and produces a :class:`ValidationReport`."""
+
+    timestamp_atol: float = 0.0  # exact-match by default
+
+    def validate(
+        self,
+        records: Sequence[EpisodeRecord],
+        staging_dir: Path,
+    ) -> ValidationReport:
+        report = ValidationReport()
+        for record in records:
+            self._validate_episode(record, staging_dir, report)
+            report.episodes_checked += 1
+        return report
+
+    def _validate_episode(
+        self,
+        record: EpisodeRecord,
+        staging_dir: Path,
+        report: ValidationReport,
+    ) -> None:
+        staging = EpisodeStaging(staging_dir, record.episode_index)
+        staged = staging.read_all()
+        all_rows: list[dict[str, Any]] = []
+        for module_name, rows in staged.items():
+            for row in rows:
+                row = {**row, "_module": module_name}
+                all_rows.append(row)
+
+        frame_ts = set(record.frame_timestamps)
+
+        events: list[dict[str, Any]] = []
+        persistent: list[dict[str, Any]] = []
+        for row in all_rows:
+            self._check_column_routing(row, report, record.episode_index)
+            if column_for_style(row.get("style")) == LANGUAGE_PERSISTENT:
+                persistent.append(row)
+            else:
+                events.append(row)
+
+        for row in events:
+            self._check_event_timestamp_alignment(row, frame_ts, report, record.episode_index)
+
+        self._check_speech_interjection_pairs(events, report, record.episode_index)
+        self._check_plan_memory_consistency(persistent, events, report, record.episode_index)
+        self._check_vqa_json(events, report, record.episode_index)
+
+    def _check_column_routing(
+        self,
+        row: dict[str, Any],
+        report: ValidationReport,
+        episode_index: int,
+    ) -> None:
+        style = row.get("style")
+        module = row.get("_module")
+        try:
+            target_col = column_for_style(style)
+        except ValueError:
+            report.add_error(f"ep={episode_index} module={module}: unknown style {style!r}")
+            return
+        if module == "module_1" and target_col != LANGUAGE_PERSISTENT:
+            report.add_error(
+                f"ep={episode_index} module=module_1 emitted style {style!r} that routes to {target_col} (must be persistent)"
+            )
+        if module in {"module_2", "module_3"} and target_col != LANGUAGE_EVENTS:
+            report.add_error(
+                f"ep={episode_index} module={module} emitted style {style!r} that routes to {target_col} (must be events)"
+            )
+
+    def _check_event_timestamp_alignment(
+        self,
+        row: dict[str, Any],
+        frame_ts: set[float],
+        report: ValidationReport,
+        episode_index: int,
+    ) -> None:
+        ts = row.get("timestamp")
+        if ts is None:
+            report.add_error(f"ep={episode_index}: event row missing timestamp: {row!r}")
+            return
+        if self.timestamp_atol == 0.0:
+            if float(ts) not in frame_ts:
+                report.add_error(
+                    f"ep={episode_index}: event row timestamp {ts!r} does not match any source frame timestamp"
+                )
+        else:
+            if not any(abs(float(ts) - f) <= self.timestamp_atol for f in frame_ts):
+                report.add_error(
+                    f"ep={episode_index}: event row timestamp {ts!r} not within {self.timestamp_atol}s of any frame"
+                )
+
+    def _check_speech_interjection_pairs(
+        self,
+        events: Iterable[dict[str, Any]],
+        report: ValidationReport,
+        episode_index: int,
+    ) -> None:
+        speech_ts: dict[float, int] = {}
+        interjection_ts: dict[float, int] = {}
+        for row in events:
+            ts = row.get("timestamp")
+            if ts is None:
+                continue
+            ts_f = float(ts)
+            if row.get("style") is None and row.get("role") == "assistant":
+                speech_ts[ts_f] = speech_ts.get(ts_f, 0) + 1
+            if row.get("style") == "interjection":
+                interjection_ts[ts_f] = interjection_ts.get(ts_f, 0) + 1
+
+        for ts in interjection_ts:
+            if ts not in speech_ts:
+                report.add_error(f"ep={episode_index}: interjection at t={ts} has no paired speech atom")
+
+    def _check_plan_memory_consistency(
+        self,
+        persistent: Sequence[dict[str, Any]],
+        events: Sequence[dict[str, Any]],
+        report: ValidationReport,
+        episode_index: int,
+    ) -> None:
+        plan_ts = sorted({float(r["timestamp"]) for r in persistent if r.get("style") == "plan"})
+        memory_ts = sorted({float(r["timestamp"]) for r in persistent if r.get("style") == "memory"})
+        subtask_ts = sorted({float(r["timestamp"]) for r in persistent if r.get("style") == "subtask"})
+        interjection_ts = sorted(
+            {
+                float(r["timestamp"])
+                for r in events
+                if r.get("style") == "interjection" and r.get("timestamp") is not None
+            }
+        )
+
+        if persistent and not plan_ts:
+            report.add_warning(f"ep={episode_index}: persistent rows present but no plan emitted")
+        # every interjection should have a same-timestamp plan refresh
+        for ts in interjection_ts:
+            if ts not in set(plan_ts):
+                report.add_error(
+                    f"ep={episode_index}: interjection at t={ts} has no co-timestamped plan update"
+                )
+        # memory should be emitted at subtask boundaries (subset relation)
+        if memory_ts and subtask_ts:
+            mem_set = set(memory_ts)
+            sub_set = set(subtask_ts)
+            stray = sorted(mem_set - sub_set)
+            if stray:
+                report.add_warning(f"ep={episode_index}: memory rows at {stray} not at any subtask boundary")
+
+    def _check_vqa_json(
+        self,
+        events: Iterable[dict[str, Any]],
+        report: ValidationReport,
+        episode_index: int,
+    ) -> None:
+        for row in events:
+            if row.get("style") != "vqa" or row.get("role") != "assistant":
+                continue
+            content = row.get("content")
+            if content is None:
+                report.add_error(
+                    f"ep={episode_index}: VQA assistant row at t={row.get('timestamp')} has null content"
+                )
+                continue
+            try:
+                payload = json.loads(content)
+            except (TypeError, ValueError) as exc:
+                report.add_error(
+                    f"ep={episode_index}: VQA assistant content not valid JSON at t={row.get('timestamp')}: {exc}"
+                )
+                continue
+            shape = classify_vqa_answer(payload)
+            if shape is None:
+                report.add_error(
+                    f"ep={episode_index}: VQA assistant payload at t={row.get('timestamp')} does not match any known shape: keys={list(payload) if isinstance(payload, dict) else type(payload).__name__}"
+                )

src/lerobot/annotations/steerable_pipeline/vlm_client.py

@@ -0,0 +1,736 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Shared Qwen-VL client.
+
+The pipeline uses a single shared VLM across modules. vLLM is preferred when
+available (high throughput, JSON-guided decoding); transformers is the
+fallback. A ``stub`` backend is used for unit tests so fixtures never call
+into a real model.
+
+The client speaks one method, :meth:`VlmClient.generate_json`, which:
+
+- accepts a list of OpenAI/HF-style multimodal messages,
+- requests JSON output (``json_mode=True`` enables guided decoding when the
+  backend supports it),
+- batches requests transparently,
+- and reprompts once on a JSON parse failure with an inline correction
+  message before raising.
+"""
+
+from __future__ import annotations
+
+import json
+import os
+import threading
+from collections.abc import Callable, Sequence
+from dataclasses import dataclass
+from typing import Any, Protocol
+
+from .config import VlmConfig
+
+
+class VlmClient(Protocol):
+    """Protocol every backend must implement."""
+
+    def generate_json(
+        self,
+        messages_batch: Sequence[Sequence[dict[str, Any]]],
+        *,
+        max_new_tokens: int | None = None,
+        temperature: float | None = None,
+    ) -> list[Any]:
+        """Generate one JSON-decoded response per messages list."""
+
+
+@dataclass
+class StubVlmClient:
+    """Deterministic stub used in unit tests.
+
+    A test passes a callable that maps the *last user message text* (or, if
+    that is empty, the full message list) to a JSON-serializable response.
+    """
+
+    responder: Callable[[Sequence[dict[str, Any]]], Any]
+
+    def generate_json(
+        self,
+        messages_batch: Sequence[Sequence[dict[str, Any]]],
+        *,
+        max_new_tokens: int | None = None,
+        temperature: float | None = None,
+    ) -> list[Any]:
+        return [self.responder(list(messages)) for messages in messages_batch]
+
+
+def _strip_to_json(text: str) -> Any:
+    text = text.strip()
+    # Strip <think>...</think> blocks (Qwen3 Thinking style)
+    while "<think>" in text and "</think>" in text:
+        start = text.find("<think>")
+        end = text.find("</think>", start) + len("</think>")
+        text = (text[:start] + text[end:]).strip()
+    # Strip ```json ... ``` fences from chat-tuned backbones
+    if text.startswith("```"):
+        first = text.find("\n")
+        last = text.rfind("```")
+        if first != -1 and last != -1 and last > first:
+            text = text[first + 1 : last].strip()
+    try:
+        return json.loads(text)
+    except (ValueError, json.JSONDecodeError):
+        pass
+    # Fall back to extracting the first balanced {...} block.
+    obj_text = _extract_first_json_object(text)
+    if obj_text is None:
+        raise json.JSONDecodeError("No JSON object found", text, 0)
+    return json.loads(obj_text)
+
+
+def _extract_first_json_object(text: str) -> str | None:
+    """Return the first balanced ``{...}`` substring, ignoring braces in
+    string literals. Returns ``None`` if no balanced block is found."""
+    start = text.find("{")
+    if start < 0:
+        return None
+    depth = 0
+    in_string = False
+    escape = False
+    for i in range(start, len(text)):
+        ch = text[i]
+        if escape:
+            escape = False
+            continue
+        if ch == "\\":
+            escape = True
+            continue
+        if ch == '"' and not escape:
+            in_string = not in_string
+            continue
+        if in_string:
+            continue
+        if ch == "{":
+            depth += 1
+        elif ch == "}":
+            depth -= 1
+            if depth == 0:
+                return text[start : i + 1]
+    return None
+
+
+@dataclass
+class _GenericTextClient:
+    """Wraps any text-generation callable in JSON-mode + one-retry semantics."""
+
+    generate_text: Callable[[Sequence[Sequence[dict[str, Any]]], int, float], list[str]]
+    config: VlmConfig
+
+    def generate_json(
+        self,
+        messages_batch: Sequence[Sequence[dict[str, Any]]],
+        *,
+        max_new_tokens: int | None = None,
+        temperature: float | None = None,
+    ) -> list[Any]:
+        max_tok = max_new_tokens if max_new_tokens is not None else self.config.max_new_tokens
+        temp = temperature if temperature is not None else self.config.temperature
+        raw = self.generate_text(messages_batch, max_tok, temp)
+        out: list[Any] = []
+        for messages, text in zip(messages_batch, raw, strict=True):
+            try:
+                out.append(_strip_to_json(text))
+                continue
+            except (ValueError, json.JSONDecodeError):
+                pass
+            retry = list(messages) + [
+                {"role": "assistant", "content": text},
+                {
+                    "role": "user",
+                    "content": (
+                        "Your previous reply was not valid JSON. "
+                        "Reply with strictly valid JSON, no prose, no fences."
+                    ),
+                },
+            ]
+            retry_text = self.generate_text([retry], max_tok, temp)[0]
+            try:
+                out.append(_strip_to_json(retry_text))
+            except (ValueError, json.JSONDecodeError):
+                # After retry: log preview and return None instead of crashing
+                # the whole pipeline. Modules treat None as "skip".
+                preview = retry_text.strip().replace("\n", " ")[:200]
+                print(
+                    f"[vlm] WARNING: failed to parse JSON after retry; preview: {preview!r}",
+                    flush=True,
+                )
+                out.append(None)
+        return out
+
+
+def make_vlm_client(config: VlmConfig) -> VlmClient:
+    """Build the shared VLM client per the configured backend.
+
+    For ``stub``, callers should construct :class:`StubVlmClient` directly with
+    a responder callable. ``stub`` here is rejected to make accidental misuse
+    obvious.
+    """
+    if config.backend == "stub":
+        raise ValueError(
+            "Use StubVlmClient(...) directly for the stub backend; make_vlm_client builds real clients."
+        )
+    if config.backend == "vllm":
+        return _make_vllm_client(config)
+    if config.backend == "transformers":
+        return _make_transformers_client(config)
+    if config.backend == "openai":
+        return _make_openai_client(config)
+    raise ValueError(f"Unknown VLM backend: {config.backend!r}")
+
+
+def _make_vllm_client(config: VlmConfig) -> VlmClient:
+    try:
+        from vllm import LLM, SamplingParams  # type: ignore[import-not-found]
+    except ImportError as exc:
+        raise ImportError(
+            "vllm is required for backend='vllm'. Install with `pip install lerobot[annotations]`."
+        ) from exc
+    # Workaround for cuDNN 9.x + torch 2.8 conv3d regression that surfaces
+    # as CUDNN_STATUS_NOT_INITIALIZED in Qwen-VL vision-tower patch
+    # embedders. Setting LEROBOT_DISABLE_CUDNN=1 forces native PyTorch
+    # convolution kernels — slower but functional.
+    import os as _os  # noqa: PLC0415
+
+    if _os.environ.get("LEROBOT_DISABLE_CUDNN", "").lower() in {"1", "true", "yes"}:
+        import torch as _torch  # noqa: PLC0415
+
+        _torch.backends.cudnn.enabled = False
+    llm_kwargs: dict[str, Any] = {
+        "model": config.model_id,
+        "tensor_parallel_size": config.tensor_parallel_size,
+        "gpu_memory_utilization": config.gpu_memory_utilization,
+        "trust_remote_code": config.trust_remote_code,
+    }
+    if config.max_model_len is not None:
+        llm_kwargs["max_model_len"] = config.max_model_len
+    llm = LLM(**llm_kwargs)
+
+    def _gen(batch: Sequence[Sequence[dict[str, Any]]], max_tok: int, temp: float) -> list[str]:
+        # ``guided_decoding`` would speed up parsing but its API differs across
+        # vllm releases (dict vs GuidedDecodingParams). The _GenericTextClient
+        # wrapper already has a one-retry JSON-recovery path, so we skip it.
+        params = SamplingParams(max_tokens=max_tok, temperature=temp)
+        # ``llm.chat`` handles chat-template application + multimodal input
+        # extraction (image/video blocks) internally, which ``llm.generate``
+        # does not.
+        outputs = llm.chat([list(m) for m in batch], params)
+        return [o.outputs[0].text for o in outputs]
+
+    return _GenericTextClient(_gen, config)
+
+
+def _make_transformers_client(config: VlmConfig) -> VlmClient:
+    try:
+        import torch  # type: ignore[import-not-found]
+        import transformers  # type: ignore[import-not-found]
+        from transformers import AutoProcessor  # type: ignore[import-not-found]
+    except ImportError as exc:
+        raise ImportError("transformers + torch are required for backend='transformers'.") from exc
+    auto_cls = (
+        getattr(transformers, "AutoModelForImageTextToText", None)
+        or getattr(transformers, "AutoModelForVision2Seq", None)
+    )
+    if auto_cls is None:
+        raise ImportError(
+            "Neither AutoModelForImageTextToText nor AutoModelForVision2Seq is available in this "
+            "transformers version. Install transformers>=4.45 (which has AutoModelForImageTextToText) "
+            "for VL models."
+        )
+    processor = AutoProcessor.from_pretrained(
+        config.model_id, trust_remote_code=config.trust_remote_code
+    )
+    import os as _os  # noqa: PLC0415
+
+    use_accelerate = _os.environ.get("LEROBOT_TRANSFORMERS_DEVICE_MAP", "manual") != "manual"
+    # ``device_map='auto'`` triggers a known std::bad_alloc on the Qwen3-VL
+    # post-load dispatch path (the alloc fails in accelerate's hook setup
+    # even with TBs of host RAM). Default to manual: load on CPU with
+    # ``low_cpu_mem_usage=True``, then ``.to("cuda")``. Set
+    # ``LEROBOT_TRANSFORMERS_DEVICE_MAP=auto`` to opt back into the old path.
+    if use_accelerate:
+        model = auto_cls.from_pretrained(
+            config.model_id,
+            torch_dtype="auto",
+            device_map="auto",
+            low_cpu_mem_usage=True,
+            trust_remote_code=config.trust_remote_code,
+        )
+    else:
+        import torch as _torch  # noqa: PLC0415
+
+        model = auto_cls.from_pretrained(
+            config.model_id,
+            torch_dtype=_torch.bfloat16,
+            low_cpu_mem_usage=True,
+            trust_remote_code=config.trust_remote_code,
+        )
+        model = model.to("cuda")
+    model.eval()
+
+    def _gen(batch: Sequence[Sequence[dict[str, Any]]], max_tok: int, temp: float) -> list[str]:
+        outs: list[str] = []
+        for messages in batch:
+            text = processor.apply_chat_template(messages, add_generation_prompt=True, tokenize=False)
+            inputs = processor(text=[text], return_tensors="pt").to(model.device)
+            with torch.no_grad():
+                gen = model.generate(
+                    **inputs,
+                    max_new_tokens=max_tok,
+                    temperature=temp,
+                    do_sample=temp > 0.0,
+                )
+            decoded = processor.batch_decode(
+                gen[:, inputs["input_ids"].shape[-1] :], skip_special_tokens=True
+            )[0]
+            outs.append(decoded)
+        return outs
+
+    return _GenericTextClient(_gen, config)
+
+
+def _make_openai_client(config: VlmConfig) -> VlmClient:
+    """Backend that talks to any OpenAI-compatible server.
+
+    Compatible with ``vllm serve``, ``transformers serve``,
+    ``ktransformers serve``, and hosted endpoints. By default the server
+    is expected to be already running. Set ``auto_serve=True`` to have
+    this client spawn one (default: ``transformers serve``), wait until
+    it's ready, and tear it down on process exit.
+
+    Image blocks ``{"type":"image", "image":<PIL.Image>}`` are
+    auto-converted to ``image_url`` data-URLs. Video blocks
+    ``{"type":"video", "video":[<PIL>...]}`` are forwarded as
+    multi-frame ``video_url`` items where supported.
+    """
+    try:
+        from openai import OpenAI  # type: ignore[import-not-found]
+    except ImportError as exc:
+        raise ImportError(
+            "openai package is required for backend='openai'. "
+            "Install with `pip install openai`."
+        ) from exc
+
+    api_base = config.api_base
+    api_key = config.api_key
+    auto_serve = config.auto_serve
+    api_bases: list[str] = [api_base]
+
+    print(
+        f"[lerobot-annotate] backend=openai model={config.model_id} "
+        f"api_base={api_base} auto_serve={auto_serve}",
+        flush=True,
+    )
+    if auto_serve:
+        if config.parallel_servers > 1:
+            print(
+                f"[lerobot-annotate] spawning {config.parallel_servers} parallel servers",
+                flush=True,
+            )
+            api_bases = _spawn_parallel_inference_servers(config)
+        elif _server_is_up(api_base):
+            print(f"[lerobot-annotate] reusing server already up at {api_base}", flush=True)
+        else:
+            print("[lerobot-annotate] no server reachable; spawning one", flush=True)
+            api_base = _spawn_inference_server(config)
+            api_bases = [api_base]
+            print(f"[lerobot-annotate] server ready at {api_base}", flush=True)
+
+    clients = [OpenAI(base_url=base, api_key=api_key) for base in api_bases]
+    client = clients[0]
+    # round-robin counter for parallel mode
+    rr_counter = {"i": 0}
+
+    # ``mm_processor_kwargs`` is a vllm-specific extra; transformers serve
+    # rejects it with HTTP 422. Send it only when explicitly opted in via
+    # an env var (e.g. ``LEROBOT_OPENAI_SEND_MM_KWARGS=1`` for vllm).
+    send_mm_kwargs = os.environ.get(
+        "LEROBOT_OPENAI_SEND_MM_KWARGS", ""
+    ).lower() in {"1", "true", "yes"}
+
+    rr_lock = threading.Lock()
+
+    def _one_call(
+        messages: Sequence[dict[str, Any]], max_tok: int, temp: float
+    ) -> str:
+        api_messages, mm_kwargs = _to_openai_messages(messages)
+        kwargs: dict[str, Any] = {
+            "model": config.model_id,
+            "messages": api_messages,
+            "max_tokens": max_tok,
+            "temperature": temp,
+        }
+        if send_mm_kwargs and mm_kwargs:
+            kwargs["extra_body"] = {
+                "mm_processor_kwargs": {**mm_kwargs, "do_sample_frames": True}
+            }
+        with rr_lock:
+            chosen = clients[rr_counter["i"] % len(clients)]
+            rr_counter["i"] += 1
+        response = chosen.chat.completions.create(**kwargs)
+        return response.choices[0].message.content or ""
+
+    def _gen(
+        batch: Sequence[Sequence[dict[str, Any]]], max_tok: int, temp: float
+    ) -> list[str]:
+        if len(batch) <= 1 or config.client_concurrency <= 1:
+            return [_one_call(messages, max_tok, temp) for messages in batch]
+        # Parallel fan-out — vllm batches these on the server side.
+        from concurrent.futures import ThreadPoolExecutor  # noqa: PLC0415
+
+        max_workers = min(config.client_concurrency, len(batch))
+        with ThreadPoolExecutor(max_workers=max_workers) as pool:
+            futures = [
+                pool.submit(_one_call, messages, max_tok, temp) for messages in batch
+            ]
+            return [f.result() for f in futures]
+
+    return _GenericTextClient(_gen, config)
+
+
+def _spawn_parallel_inference_servers(config: VlmConfig) -> list[str]:
+    """Spawn ``config.parallel_servers`` independent vllm replicas.
+
+    Each replica:
+    - is pinned to a single GPU via ``CUDA_VISIBLE_DEVICES``
+    - listens on ``serve_port + i``
+    - is shut down via the same atexit hook as the single-server path
+
+    Returns the list of ``api_base`` URLs the client should round-robin
+    across.
+    """
+    import atexit  # noqa: PLC0415
+    import os as _os  # noqa: PLC0415
+    import shlex  # noqa: PLC0415
+    import signal  # noqa: PLC0415
+    import subprocess  # noqa: PLC0415
+    import sys  # noqa: PLC0415
+    import threading  # noqa: PLC0415
+    import time  # noqa: PLC0415
+
+    n = config.parallel_servers
+    api_bases: list[str] = []
+    procs: list[subprocess.Popen] = []
+    ready_events: list[threading.Event] = []
+    # Multiple readiness signals — uvicorn's own banner is suppressed at
+    # ``--uvicorn-log-level warning``, so we also accept vllm's own
+    # "Starting vLLM API server" line and the route-listing line. The
+    # HTTP probe below is the ultimate fallback.
+    ready_markers = (
+        "Uvicorn running",
+        "Application startup complete",
+        "Starting vLLM API server",
+        "Available routes are",
+    )
+    # Single lock for all server-stream threads so multibyte chars from
+    # different servers don't interleave and tear UTF-8 sequences.
+    print_lock = threading.Lock()
+
+    base_cmd = config.serve_command or (
+        f"vllm serve {shlex.quote(config.model_id)} "
+        f"--tensor-parallel-size 1 "
+        f"--max-model-len {config.max_model_len or 32768} "
+        f"--uvicorn-log-level warning"
+    )
+
+    for i in range(n):
+        port = config.serve_port + i
+        env = _os.environ.copy()
+        env["CUDA_VISIBLE_DEVICES"] = str(i)
+        cmd = base_cmd
+        if "{port}" in cmd:
+            cmd = cmd.replace("{port}", str(port))
+        else:
+            cmd = f"{cmd} --port {port}"
+        api_base = f"http://localhost:{port}/v1"
+        api_bases.append(api_base)
+        print(f"[server-{i}] launching on GPU {i} port {port}: {cmd}", flush=True)
+        proc = subprocess.Popen(
+            shlex.split(cmd),
+            stdout=subprocess.PIPE,
+            stderr=subprocess.STDOUT,
+            text=True,
+            bufsize=1,
+            env=env,
+        )
+        procs.append(proc)
+        ready = threading.Event()
+        ready_events.append(ready)
+
+        def _stream(idx: int, p: subprocess.Popen, ev: threading.Event) -> None:
+            # Read whole lines and emit each line atomically under the
+            # shared print_lock so output from N servers stays readable.
+            assert p.stdout is not None
+            for line in iter(p.stdout.readline, ""):
+                with print_lock:
+                    sys.stdout.write(f"[server-{idx}] {line}")
+                    if not line.endswith(("\n", "\r")):
+                        sys.stdout.write("\n")
+                    sys.stdout.flush()
+                if any(m in line for m in ready_markers):
+                    ev.set()
+
+        threading.Thread(target=_stream, args=(i, proc, ready), daemon=True).start()
+
+        def _probe(idx: int, base: str, ev: threading.Event, p: subprocess.Popen) -> None:
+            while not ev.is_set() and p.poll() is None:
+                if _server_is_up(base):
+                    print(f"[server-{idx}] ready (http probe)", flush=True)
+                    ev.set()
+                    return
+                time.sleep(2)
+
+        threading.Thread(target=_probe, args=(i, api_base, ready, proc), daemon=True).start()
+
+    def _shutdown() -> None:
+        for i, p in enumerate(procs):
+            if p.poll() is None:
+                print(f"[server-{i}] stopping pid={p.pid}", flush=True)
+                p.send_signal(signal.SIGINT)
+        for p in procs:
+            try:
+                p.wait(timeout=15)
+            except subprocess.TimeoutExpired:
+                p.kill()
+                p.wait(timeout=5)
+
+    atexit.register(_shutdown)
+
+    deadline = time.monotonic() + config.serve_ready_timeout_s
+    while any(not ev.is_set() for ev in ready_events) and time.monotonic() < deadline:
+        for i, p in enumerate(procs):
+            if p.poll() is not None:
+                raise RuntimeError(
+                    f"[server-{i}] inference server exited unexpectedly with rc={p.returncode}"
+                )
+        time.sleep(2)
+    if any(not ev.is_set() for ev in ready_events):
+        raise RuntimeError(
+            f"[server] not all replicas became ready within {config.serve_ready_timeout_s}s"
+        )
+    print(f"[lerobot-annotate] all {n} servers ready: {api_bases}", flush=True)
+    return api_bases
+
+
+def _server_is_up(api_base: str) -> bool:
+    """Return True if ``api_base/models`` answers 200 within 2 seconds."""
+    import urllib.request  # noqa: PLC0415
+
+    url = api_base.rstrip("/") + "/models"
+    try:
+        with urllib.request.urlopen(url, timeout=2) as resp:
+            return resp.status == 200
+    except Exception:  # noqa: BLE001
+        return False
+
+
+def _spawn_inference_server(config: VlmConfig) -> str:
+    """Spawn ``transformers serve`` (or ``serve_command``), wait until it
+    accepts ``/v1/models``, and register a shutdown hook.
+
+    Streams the server's stdout/stderr to the parent terminal in
+    real-time on a background thread so users can see model-load
+    progress and errors as they happen.
+
+    Returns the full ``api_base`` URL the OpenAI client should use.
+    """
+    import atexit  # noqa: PLC0415
+    import shlex  # noqa: PLC0415
+    import signal  # noqa: PLC0415
+    import subprocess  # noqa: PLC0415
+    import sys  # noqa: PLC0415
+    import threading  # noqa: PLC0415
+    import time  # noqa: PLC0415
+    import urllib.request  # noqa: PLC0415
+
+    cmd = config.serve_command
+    if not cmd:
+        cmd = (
+            f"transformers serve {shlex.quote(config.model_id)} "
+            f"--port {config.serve_port} --continuous-batching"
+        )
+    api_base = f"http://localhost:{config.serve_port}/v1"
+    print(f"[server] launching: {cmd}", flush=True)
+    proc = subprocess.Popen(
+        shlex.split(cmd),
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT,
+        text=True,
+        bufsize=1,
+    )
+
+    # Watch the server output for the uvicorn readiness banner. This is
+    # more reliable than polling /v1/models because transformers serve
+    # rescans its cache on every model-list request, which can exceed
+    # the urllib timeout and trigger an infinite probe loop.
+    ready_event = threading.Event()
+    # See _spawn_parallel_inference_servers for why we accept these.
+    ready_markers = (
+        "Uvicorn running",
+        "Application startup complete",
+        "Starting vLLM API server",
+        "Available routes are",
+    )
+
+    def _probe() -> None:
+        while not ready_event.is_set() and proc.poll() is None:
+            if _server_is_up(api_base):
+                print("[server] ready (http probe)", flush=True)
+                ready_event.set()
+                return
+            time.sleep(2)
+
+    threading.Thread(target=_probe, daemon=True).start()
+
+    def _stream_output() -> None:
+        # Read raw chunks instead of iterating lines so tqdm progress
+        # bars (which overwrite using \r) flush in real time.
+        assert proc.stdout is not None
+        buf = ""
+        prefix_started = False
+        while True:
+            ch = proc.stdout.read(1)
+            if ch == "":
+                # process exited; flush any tail
+                if buf:
+                    sys.stdout.write(buf)
+                    sys.stdout.flush()
+                return
+            if not prefix_started:
+                sys.stdout.write("[server] ")
+                prefix_started = True
+            sys.stdout.write(ch)
+            sys.stdout.flush()
+            buf += ch
+            if ch in ("\n", "\r"):
+                if any(marker in buf for marker in ready_markers):
+                    ready_event.set()
+                buf = ""
+                prefix_started = False
+
+    threading.Thread(target=_stream_output, daemon=True).start()
+
+    def _shutdown() -> None:
+        if proc.poll() is None:
+            print(f"[server] stopping pid={proc.pid}", flush=True)
+            proc.send_signal(signal.SIGINT)
+            try:
+                proc.wait(timeout=15)
+            except subprocess.TimeoutExpired:
+                proc.kill()
+                proc.wait(timeout=5)
+
+    atexit.register(_shutdown)
+
+    deadline = time.monotonic() + config.serve_ready_timeout_s
+    while time.monotonic() < deadline:
+        if proc.poll() is not None:
+            raise RuntimeError(
+                f"[server] inference server exited unexpectedly with rc={proc.returncode}. "
+                f"See [server] log lines above for the cause."
+            )
+        if ready_event.wait(timeout=2):
+            return api_base
+    proc.terminate()
+    raise RuntimeError(
+        f"[server] did not become ready within {config.serve_ready_timeout_s}s"
+    )
+
+
+def _to_openai_messages(
+    messages: Sequence[dict[str, Any]],
+) -> tuple[list[dict[str, Any]], dict[str, Any]]:
+    """Convert internal messages to OpenAI chat format.
+
+    Returns ``(api_messages, mm_kwargs)``. Multimodal-processor kwargs
+    (``fps`` from ``video_url`` blocks) are extracted out so the caller
+    can pass them via ``extra_body.mm_processor_kwargs`` rather than
+    inside the content blocks (which transformers serve rejects).
+
+    File-URL video blocks are inlined as base64 data URLs.
+    """
+    out_messages: list[dict[str, Any]] = []
+    mm_kwargs: dict[str, Any] = {}
+    for message in messages:
+        content = message.get("content")
+        if not isinstance(content, list):
+            out_messages.append({"role": message["role"], "content": content})
+            continue
+        out_blocks: list[dict[str, Any]] = []
+        for block in content:
+            block_type = block.get("type") if isinstance(block, dict) else None
+            if block_type == "text":
+                out_blocks.append({"type": "text", "text": block.get("text", "")})
+            elif block_type == "image":
+                out_blocks.append(
+                    {"type": "image_url", "image_url": {"url": _pil_to_data_url(block["image"])}}
+                )
+            elif block_type == "video":
+                frames = block.get("video", [])
+                for img in frames:
+                    out_blocks.append(
+                        {"type": "image_url", "image_url": {"url": _pil_to_data_url(img)}}
+                    )
+            elif block_type == "video_url":
+                video_url = dict(block["video_url"])
+                url = video_url.get("url", "")
+                if url.startswith("file://"):
+                    video_url["url"] = _file_to_data_url(url[len("file://") :])
+                out_blocks.append({"type": "video_url", "video_url": video_url})
+                fps = block.get("fps")
+                if fps is not None:
+                    mm_kwargs["fps"] = fps
+            else:
+                out_blocks.append(block)
+        out_messages.append({"role": message["role"], "content": out_blocks})
+    return out_messages, mm_kwargs
+
+
+def _file_to_data_url(path: str) -> str:
+    """Read a local video file and return a base64 ``data:video/mp4`` URL."""
+    import base64  # noqa: PLC0415
+
+    with open(path, "rb") as f:
+        b64 = base64.b64encode(f.read()).decode("ascii")
+    return f"data:video/mp4;base64,{b64}"
+
+
+def _pil_to_data_url(image: Any) -> str:
+    """Encode a PIL.Image as a base64 data URL."""
+    import base64  # noqa: PLC0415
+    import io  # noqa: PLC0415
+
+    buf = io.BytesIO()
+    image.save(buf, format="PNG")
+    b64 = base64.b64encode(buf.getvalue()).decode("ascii")
+    return f"data:image/png;base64,{b64}"
+
+
+def _messages_to_prompt(messages: Sequence[dict[str, Any]]) -> Any:
+    """Pass-through hook used by the vllm backend.
+
+    vllm exposes its own multimodal entry points that vary by version; for the
+    base flow we simply forward the raw message list and let the caller's
+    custom backend handle templating. Real deployments override this.
+    """
+    return list(messages)

src/lerobot/annotations/steerable_pipeline/writer.py

@@ -0,0 +1,339 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Final parquet rewrite.
+
+For every episode the writer:
+
+1. reads the staged module outputs,
+2. partitions them into a persistent slice (PERSISTENT_STYLES) and an event
+   slice (EVENT_ONLY_STYLES + style=None tool-call atoms),
+3. sorts each slice deterministically,
+4. broadcasts the persistent slice across every frame in the episode,
+5. for each frame, materializes the sublist of event rows whose timestamp
+   exactly equals that frame's timestamp,
+6. drops the legacy ``subtask_index`` column,
+7. adds a top-level ``tools`` column containing the JSON schema for ``say``,
+8. writes the parquet shard back in place.
+
+Invariants enforced here (and re-checked by the validator):
+
+- per-episode persistent slice is byte-identical across every frame;
+- ``language_events`` rows on a frame all have ``timestamp == frame_ts``
+  (timestamps come straight from the source parquet — never recomputed);
+- every row passes ``column_for_style(style)``.
+"""
+
+from __future__ import annotations
+
+import json
+import logging
+from collections import defaultdict
+from collections.abc import Iterable, Sequence
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any
+
+import pyarrow as pa
+import pyarrow.parquet as pq
+
+from lerobot.datasets.language import (
+    EVENT_ONLY_STYLES,
+    LANGUAGE_EVENTS,
+    LANGUAGE_PERSISTENT,
+    PERSISTENT_STYLES,
+    column_for_style,
+)
+
+from .reader import EpisodeRecord
+from .staging import EpisodeStaging
+
+logger = logging.getLogger(__name__)
+
+
+SAY_TOOL_SCHEMA: dict[str, Any] = {
+    "type": "function",
+    "function": {
+        "name": "say",
+        "description": "Speak a short utterance to the user via the TTS executor.",
+        "parameters": {
+            "type": "object",
+            "properties": {
+                "text": {
+                    "type": "string",
+                    "description": "The verbatim text to speak.",
+                }
+            },
+            "required": ["text"],
+        },
+    },
+}
+
+
+def _row_persistent_sort_key(row: dict[str, Any]) -> tuple:
+    return (float(row["timestamp"]), row.get("style") or "", row.get("role") or "")
+
+
+def _row_event_sort_key(row: dict[str, Any]) -> tuple:
+    # events are bucketed per-frame, but within a frame we still want determinism
+    return (row.get("style") or "", row.get("role") or "")
+
+
+def _normalize_persistent_row(row: dict[str, Any]) -> dict[str, Any]:
+    """Coerce a staged row into the persistent column's struct shape."""
+    style = row.get("style")
+    if style not in PERSISTENT_STYLES:
+        raise ValueError(
+            f"persistent slice contains row with non-persistent style {style!r}; "
+            "row would be misrouted under column_for_style()"
+        )
+    if "timestamp" not in row:
+        raise ValueError(f"persistent row missing timestamp: {row!r}")
+    return {
+        "role": str(row["role"]),
+        "content": None if row.get("content") is None else str(row["content"]),
+        "style": style,
+        "timestamp": float(row["timestamp"]),
+        "tool_calls": _normalize_tool_calls(row.get("tool_calls")),
+    }
+
+
+def _normalize_event_row(row: dict[str, Any]) -> dict[str, Any]:
+    """Coerce a staged row into the event column's struct shape (no timestamp)."""
+    style = row.get("style")
+    if style is not None and style not in EVENT_ONLY_STYLES:
+        raise ValueError(
+            f"event slice contains row with style {style!r}; expected None or one of {EVENT_ONLY_STYLES}"
+        )
+    if column_for_style(style) != LANGUAGE_EVENTS:
+        raise ValueError(f"event row with style {style!r} would not route to language_events")
+    return {
+        "role": str(row["role"]),
+        "content": None if row.get("content") is None else str(row["content"]),
+        "style": style,
+        "tool_calls": _normalize_tool_calls(row.get("tool_calls")),
+    }
+
+
+def _normalize_tool_calls(value: Any) -> list[Any] | None:
+    if value is None:
+        return None
+    if not isinstance(value, list):
+        raise ValueError(f"tool_calls must be a list or None, got {type(value).__name__}")
+    return list(value)
+
+
+def _validate_atom_invariants(row: dict[str, Any]) -> None:
+    """At-least-one of content/tool_calls; style=None implies tool_calls."""
+    has_content = row.get("content") is not None
+    has_tools = row.get("tool_calls") is not None
+    if not (has_content or has_tools):
+        raise ValueError(f"row has neither content nor tool_calls: {row!r}")
+    if row.get("style") is None and not has_tools:
+        raise ValueError(f"style=None requires tool_calls: {row!r}")
+
+
+def _validate_speech_atom(row: dict[str, Any]) -> None:
+    """Speech atoms: role=assistant, style=None, content=None, say tool call."""
+    if row.get("style") is not None:
+        return  # not a speech atom
+    if row.get("role") != "assistant":
+        raise ValueError(f"speech atom must have role=assistant: {row!r}")
+    if row.get("content") is not None:
+        raise ValueError(f"speech atom must have content=null: {row!r}")
+    tool_calls = row.get("tool_calls")
+    if not tool_calls or not isinstance(tool_calls, list):
+        raise ValueError(f"speech atom must have non-empty tool_calls list: {row!r}")
+    first = tool_calls[0]
+    if not isinstance(first, dict):
+        raise ValueError(f"speech atom tool_calls[0] must be a dict: {row!r}")
+    if first.get("type") != "function":
+        raise ValueError(f"speech atom tool_calls[0].type must be 'function': {row!r}")
+    fn = first.get("function") or {}
+    if fn.get("name") != "say":
+        raise ValueError(f"speech atom tool_calls[0].function.name must be 'say': {row!r}")
+    args = fn.get("arguments") or {}
+    if not isinstance(args, dict) or "text" not in args or not isinstance(args["text"], str):
+        raise ValueError(f"speech atom must carry 'text' string in arguments: {row!r}")
+
+
+@dataclass
+class LanguageColumnsWriter:
+    """Rewrite ``data/chunk-*/file-*.parquet`` with the two language columns."""
+
+    drop_existing_subtask_index: bool = True
+
+    def write_all(
+        self,
+        records: Sequence[EpisodeRecord],
+        staging_dir: Path,
+        root: Path,
+    ) -> list[Path]:
+        episodes_by_path: dict[Path, list[EpisodeRecord]] = defaultdict(list)
+        for record in records:
+            episodes_by_path[record.data_path].append(record)
+
+        written: list[Path] = []
+        for path, eps in episodes_by_path.items():
+            self._rewrite_one(path, eps, staging_dir, root)
+            written.append(path)
+        return written
+
+    def _rewrite_one(
+        self,
+        path: Path,
+        episodes: Sequence[EpisodeRecord],
+        staging_dir: Path,
+        root: Path,
+    ) -> None:
+        table = pq.read_table(path)
+        n_rows = table.num_rows
+
+        # Ensure we cover every episode in the file. Episodes that don't have
+        # staging artifacts are passed through with empty annotation lists —
+        # this keeps the writer idempotent and safe for partial reruns.
+        staged_per_ep: dict[int, dict[str, list[dict[str, Any]]]] = {}
+        for record in episodes:
+            staging = EpisodeStaging(staging_dir, record.episode_index)
+            staged_per_ep[record.episode_index] = staging.read_all()
+
+        persistent_by_ep: dict[int, list[dict[str, Any]]] = {}
+        events_by_ep_ts: dict[int, dict[float, list[dict[str, Any]]]] = {}
+
+        for ep_index, ep_staged in staged_per_ep.items():
+            persistent_rows: list[dict[str, Any]] = []
+            event_rows: list[dict[str, Any]] = []  # carry timestamp until bucketed
+            for _module_name, rows in ep_staged.items():
+                for row in rows:
+                    style = row.get("style")
+                    if column_for_style(style) == LANGUAGE_PERSISTENT:
+                        persistent_rows.append(row)
+                    else:
+                        event_rows.append(row)
+
+            persistent_rows.sort(key=_row_persistent_sort_key)
+            normalized_persistent = []
+            for r in persistent_rows:
+                _validate_atom_invariants(r)
+                _validate_speech_atom(r)
+                normalized_persistent.append(_normalize_persistent_row(r))
+            persistent_by_ep[ep_index] = normalized_persistent
+
+            buckets: dict[float, list[dict[str, Any]]] = defaultdict(list)
+            for r in event_rows:
+                _validate_atom_invariants(r)
+                _validate_speech_atom(r)
+                ts = float(r["timestamp"])
+                buckets[ts].append(_normalize_event_row(r))
+            for ts in list(buckets.keys()):
+                buckets[ts].sort(key=_row_event_sort_key)
+            events_by_ep_ts[ep_index] = buckets
+
+        episode_col = (
+            table.column("episode_index").to_pylist() if "episode_index" in table.column_names else None
+        )
+        ts_col = table.column("timestamp").to_pylist() if "timestamp" in table.column_names else None
+        if episode_col is None or ts_col is None:
+            raise ValueError(f"{path} is missing 'episode_index' or 'timestamp' — required by the writer.")
+
+        per_row_persistent: list[list[dict[str, Any]]] = []
+        per_row_events: list[list[dict[str, Any]]] = []
+        for i in range(n_rows):
+            ep = episode_col[i]
+            ts = float(ts_col[i])
+            per_row_persistent.append(persistent_by_ep.get(ep, []))
+            buckets = events_by_ep_ts.get(ep, {})
+            per_row_events.append(buckets.get(ts, []))
+
+        new_table = self._materialize_table(
+            table, per_row_persistent, per_row_events, drop_old=self.drop_existing_subtask_index
+        )
+        pq.write_table(new_table, path)
+
+    def _materialize_table(
+        self,
+        table: pa.Table,
+        persistent: list[list[dict[str, Any]]],
+        events: list[list[dict[str, Any]]],
+        *,
+        drop_old: bool,
+    ) -> pa.Table:
+        cols = []
+        names = []
+        for name in table.column_names:
+            if drop_old and name == "subtask_index":
+                continue
+            if name in (LANGUAGE_PERSISTENT, LANGUAGE_EVENTS, "tools"):
+                continue  # we'll re-add canonical versions
+            cols.append(table.column(name))
+            names.append(name)
+
+        # We let pyarrow infer struct/list schema rather than passing the
+        # canonical type from `lerobot.datasets.language` directly: that type
+        # uses `pa.json_()` for the `tool_calls` element type, which
+        # `pa.array(..., type=...)` cannot materialize from Python lists on
+        # current pyarrow versions. The inferred schema round-trips through
+        # parquet and `LeRobotDataset` correctly — see PR 1's
+        # `tests/datasets/test_language.py` which exercises the same flow.
+        persistent_arr = pa.array(persistent)
+        events_arr = pa.array(events)
+
+        cols.extend([persistent_arr, events_arr])
+        names.extend([LANGUAGE_PERSISTENT, LANGUAGE_EVENTS])
+
+        # Dataset-level tools column. Store the JSON schema as a string per
+        # row (broadcast-identical, parquet dictionary-encodes it) — string
+        # storage avoids requiring pa.json_() on every consumer.
+        tools_json = json.dumps([SAY_TOOL_SCHEMA], sort_keys=True)
+        tools_arr = pa.array([tools_json] * table.num_rows, type=pa.string())
+        cols.append(tools_arr)
+        names.append("tools")
+
+        return pa.Table.from_arrays(cols, names=names)
+
+
+def speech_atom(timestamp: float, text: str) -> dict[str, Any]:
+    """Build a canonical speech tool-call atom for the events column."""
+    return {
+        "role": "assistant",
+        "content": None,
+        "style": None,
+        "timestamp": float(timestamp),
+        "tool_calls": [
+            {
+                "type": "function",
+                "function": {
+                    "name": "say",
+                    "arguments": {"text": text},
+                },
+            }
+        ],
+    }
+
+
+def normalize_rows_for_writer(
+    rows: Iterable[dict[str, Any]],
+) -> tuple[list[dict[str, Any]], list[dict[str, Any]]]:
+    """Helper used by tests/validators to partition a flat row list into
+    (persistent_rows, event_rows) using ``column_for_style``.
+    """
+    persistent: list[dict[str, Any]] = []
+    events: list[dict[str, Any]] = []
+    for row in rows:
+        if column_for_style(row.get("style")) == LANGUAGE_PERSISTENT:
+            persistent.append(row)
+        else:
+            events.append(row)
+    return persistent, events

src/lerobot/cameras/realsense/camera_realsense.py

@@ -17,7 +17,6 @@ Provides the RealSenseCamera class for capturing frames from Intel RealSense cam
 """
 
 import logging
-import sys
 import time
 from threading import Event, Lock, Thread
 from typing import TYPE_CHECKING, Any
@@ -42,7 +41,6 @@ from ..utils import get_cv2_rotation
 from .configuration_realsense import RealSenseCameraConfig
 
 logger = logging.getLogger(__name__)
-pkg_name = "pyrealsense2-macosx" if sys.platform == "darwin" else "pyrealsense2"
 
 
 class RealSenseCamera(Camera):
@@ -116,7 +114,7 @@ class RealSenseCamera(Camera):
         Args:
             config: The configuration settings for the camera.
         """
-        require_package(pkg_name, extra="intelrealsense", import_name="pyrealsense2")
+        require_package("pyrealsense2", extra="intelrealsense")
         super().__init__(config)
 
         self.config = config
@@ -133,9 +131,6 @@ class RealSenseCamera(Camera):
 
         self.rs_pipeline: rs.pipeline | None = None
         self.rs_profile: rs.pipeline_profile | None = None
-        # Meters per uint16 unit on the depth stream. Queried from the device
-        # at connect() time. Typical D-series value is 0.001 (= 1 mm/unit).
-        self.depth_scale: float | None = None
 
         self.thread: Thread | None = None
         self.stop_event: Event | None = None
@@ -193,17 +188,6 @@ class RealSenseCamera(Camera):
             ) from e
 
         self._configure_capture_settings()
-
-        # Query depth scale (meters per uint16 unit) when depth is enabled so
-        # consumers can convert the raw z16 stream to metric distances.
-        if self.use_depth and self.rs_profile is not None:
-            try:
-                depth_sensor = self.rs_profile.get_device().first_depth_sensor()
-                self.depth_scale = float(depth_sensor.get_depth_scale())
-            except RuntimeError as e:
-                logger.warning(f"{self}: failed to query depth scale ({e}); falling back to 0.001 m/unit.")
-                self.depth_scale = 0.001
-
         self._start_read_thread()
 
         # NOTE(Steven/Caroline): Enforcing at least one second of warmup as RS cameras need a bit of time before the first read. If we don't wait, the first read from the warmup will raise.
@@ -546,6 +530,7 @@ class RealSenseCamera(Camera):
             self.latest_timestamp = None
             self.new_frame_event.clear()
 
+    # NOTE(Steven): Missing implementation for depth for now
     @check_if_not_connected
     def async_read(self, timeout_ms: float = 200) -> NDArray[Any]:
         """
@@ -588,6 +573,7 @@ class RealSenseCamera(Camera):
 
         return frame
 
+    # NOTE(Steven): Missing implementation for depth for now
     @check_if_not_connected
     def read_latest(self, max_age_ms: int = 500) -> NDArray[Any]:
         """Return the most recent (color) frame captured immediately (Peeking).
@@ -623,78 +609,6 @@ class RealSenseCamera(Camera):
 
         return frame
 
-
-    @check_if_not_connected
-    def async_read_depth(self, timeout_ms: float = 200) -> NDArray[Any]:
-        """Read the latest depth frame asynchronously, in metric meters.
-
-        Mirrors :meth:`async_read` but returns the depth stream rather than the
-        color stream. Output is ``np.uint16`` of shape ``(H, W)``.
-
-        Raises:
-            DeviceNotConnectedError: If the camera is not connected.
-            RuntimeError: If ``use_depth`` is ``False`` for this camera, or if
-                the background read thread is not running.
-            TimeoutError: If no frame becomes available within ``timeout_ms``.
-        """
-        if not self.use_depth:
-            raise RuntimeError(
-                f"{self}: cannot read depth — camera was configured with use_depth=False."
-            )
-
-        if self.thread is None or not self.thread.is_alive():
-            raise RuntimeError(f"{self} read thread is not running.")
-
-        if not self.new_frame_event.wait(timeout=timeout_ms / 1000.0):
-            raise TimeoutError(
-                f"Timed out waiting for depth frame from camera {self} after {timeout_ms} ms."
-            )
-
-        with self.frame_lock:
-            depth_frame = self.latest_depth_frame
-            self.new_frame_event.clear()
-
-        if depth_frame is None:
-            raise RuntimeError(f"Internal error: Event set but no depth frame available for {self}.")
-
-        return depth_frame
-
-    @check_if_not_connected
-    def read_latest_depth(self, max_age_ms: int = 500) -> NDArray[Any]:
-        """Return the most recent depth frame in metric meters (peeking).
-
-        Non-blocking counterpart of :meth:`read_latest` for the depth stream.
-        Output is ``np.float32`` of shape ``(H, W)`` in meters.
-
-        Raises:
-            DeviceNotConnectedError: If the camera is not connected.
-            RuntimeError: If ``use_depth`` is ``False`` for this camera, or if
-                no depth frame has been captured yet.
-            TimeoutError: If the latest depth frame is older than ``max_age_ms``.
-        """
-        if not self.use_depth:
-            raise RuntimeError(
-                f"{self}: cannot read depth — camera was configured with use_depth=False."
-            )
-
-        if self.thread is None or not self.thread.is_alive():
-            raise RuntimeError(f"{self} read thread is not running.")
-
-        with self.frame_lock:
-            depth_frame = self.latest_depth_frame
-            timestamp = self.latest_timestamp
-
-        if depth_frame is None or timestamp is None:
-            raise RuntimeError(f"{self} has not captured any depth frames yet.")
-
-        age_ms = (time.perf_counter() - timestamp) * 1e3
-        if age_ms > max_age_ms:
-            raise TimeoutError(
-                f"{self} latest depth frame is too old: {age_ms:.1f} ms (max allowed: {max_age_ms} ms)."
-            )
-
-        return depth_frame
-
     def disconnect(self) -> None:
         """
         Disconnects from the camera, stops the pipeline, and cleans up resources.
@@ -718,8 +632,6 @@ class RealSenseCamera(Camera):
             self.rs_pipeline = None
             self.rs_profile = None
 
-        self.depth_scale = None
-
         with self.frame_lock:
             self.latest_color_frame = None
             self.latest_depth_frame = None

src/lerobot/common/wandb_utils.py

@@ -41,12 +41,8 @@ def cfg_to_group(
             return tag
         return tag[:max_tag_length]
 
-    if cfg.is_reward_model_training:
-        trainable_tag = f"reward_model:{cfg.reward_model.type}"
-    else:
-        trainable_tag = f"policy:{cfg.policy.type}"
     lst = [
-        trainable_tag,
+        f"policy:{cfg.policy.type}",
         f"seed:{cfg.seed}",
     ]
     if cfg.dataset is not None:

src/lerobot/configs/__init__.py

@@ -21,9 +21,9 @@ are intentionally NOT re-exported here to avoid circular dependencies
 Import them directly: ``from lerobot.configs.train import TrainPipelineConfig``
 """
 
-from .dataset import DatasetRecordConfig
 from .default import DatasetConfig, EvalConfig, PeftConfig, WandBConfig
 from .policies import PreTrainedConfig
+from .recipe import MessageTurn, TrainingRecipe, load_recipe
 from .types import (
     FeatureType,
     NormalizationMode,
@@ -40,10 +40,12 @@ __all__ = [
     "PolicyFeature",
     "RTCAttentionSchedule",
     # Config classes
-    "DatasetRecordConfig",
     "DatasetConfig",
     "EvalConfig",
+    "MessageTurn",
     "PeftConfig",
     "PreTrainedConfig",
+    "TrainingRecipe",
     "WandBConfig",
+    "load_recipe",
 ]

src/lerobot/configs/dataset.py

@@ -1,80 +0,0 @@
-# Copyright 2024 The HuggingFace Inc. team. All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-"""Shared dataset recording configuration used by both ``lerobot-record`` and ``lerobot-rollout``."""
-
-from dataclasses import dataclass
-from datetime import datetime
-from pathlib import Path
-
-
-@dataclass
-class DatasetRecordConfig:
-    # Dataset identifier. By convention it should match '{hf_username}/{dataset_name}' (e.g. `lerobot/test`).
-    repo_id: str = ""
-    # A short but accurate description of the task performed during the recording (e.g. "Pick the Lego block and drop it in the box on the right.")
-    single_task: str = ""
-    # Root directory where the dataset will be stored (e.g. 'dataset/path'). If None, defaults to $HF_LEROBOT_HOME/repo_id.
-    root: str | Path | None = None
-    # Limit the frames per second.
-    fps: int = 30
-    # Number of seconds for data recording for each episode.
-    episode_time_s: int | float = 60
-    # Number of seconds for resetting the environment after each episode.
-    reset_time_s: int | float = 60
-    # Number of episodes to record.
-    num_episodes: int = 50
-    # Encode frames in the dataset into video
-    video: bool = True
-    # Upload dataset to Hugging Face hub.
-    push_to_hub: bool = True
-    # Upload on private repository on the Hugging Face hub.
-    private: bool = False
-    # Add tags to your dataset on the hub.
-    tags: list[str] | None = None
-    # Number of subprocesses handling the saving of frames as PNG. Set to 0 to use threads only;
-    # set to ≥1 to use subprocesses, each using threads to write images. The best number of processes
-    # and threads depends on your system. We recommend 4 threads per camera with 0 processes.
-    # If fps is unstable, adjust the thread count. If still unstable, try using 1 or more subprocesses.
-    num_image_writer_processes: int = 0
-    # Number of threads writing the frames as png images on disk, per camera.
-    # Too many threads might cause unstable teleoperation fps due to main thread being blocked.
-    # Not enough threads might cause low camera fps.
-    num_image_writer_threads_per_camera: int = 4
-    # Number of episodes to record before batch encoding videos
-    # Set to 1 for immediate encoding (default behavior), or higher for batched encoding
-    video_encoding_batch_size: int = 1
-    # Video codec for encoding videos. Options: 'h264', 'hevc', 'libsvtav1', 'auto',
-    # or hardware-specific: 'h264_videotoolbox', 'h264_nvenc', 'h264_vaapi', 'h264_qsv'.
-    # Use 'auto' to auto-detect the best available hardware encoder.
-    vcodec: str = "libsvtav1"
-    # Enable streaming video encoding: encode frames in real-time during capture instead
-    # of writing PNG images first. Makes save_episode() near-instant. More info in the documentation: https://huggingface.co/docs/lerobot/streaming_video_encoding
-    streaming_encoding: bool = False
-    # Maximum number of frames to buffer per camera when using streaming encoding.
-    # ~1s buffer at 30fps. Provides backpressure if the encoder can't keep up.
-    encoder_queue_maxsize: int = 30
-    # Number of threads per encoder instance. None = auto (codec default).
-    # Lower values reduce CPU usage, maps to 'lp' (via svtav1-params) for libsvtav1 and 'threads' for h264/hevc..
-    encoder_threads: int | None = None
-
-    def stamp_repo_id(self) -> None:
-        """Append a date-time tag to ``repo_id`` so each recording session gets a unique name.
-
-        Must be called explicitly at dataset *creation* time — not on resume,
-        where the existing ``repo_id`` (already stamped) must be preserved.
-        """
-        if self.repo_id:
-            timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
-            self.repo_id = f"{self.repo_id}_{timestamp}"

src/lerobot/configs/default.py

@@ -17,7 +17,7 @@
 from dataclasses import dataclass, field
 
 from lerobot.transforms import ImageTransformsConfig
-from lerobot.utils.import_utils import get_safe_default_video_backend
+from lerobot.utils.import_utils import get_safe_default_codec
 
 
 @dataclass
@@ -34,7 +34,7 @@ class DatasetConfig:
     image_transforms: ImageTransformsConfig = field(default_factory=ImageTransformsConfig)
     revision: str | None = None
     use_imagenet_stats: bool = True
-    video_backend: str = field(default_factory=get_safe_default_video_backend)
+    video_backend: str = field(default_factory=get_safe_default_codec)
     # When True, video frames are returned as uint8 tensors (0-255) instead of float32 (0.0-1.0).
     # This reduces memory and speeds up DataLoader IPC. The training pipeline handles the conversion.
     return_uint8: bool = False

src/lerobot/configs/recipe.py

@@ -0,0 +1,193 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import annotations
+
+import re
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any, Literal, get_args
+
+MessageRole = Literal["user", "assistant", "system", "tool"]
+MessageStream = Literal["high_level", "low_level"]
+
+DEFAULT_BINDINGS = {
+    "subtask": "active_at(t, style=subtask)",
+    "memory": "active_at(t, style=memory)",
+    "plan": "active_at(t, style=plan)",
+    "speech": "emitted_at(t, role=assistant, tool_name=say)",
+    "interjection": "emitted_at(t, style=interjection)",
+    "vqa": "emitted_at(t, style=vqa, role=assistant)",
+    "vqa_query": "emitted_at(t, style=vqa, role=user)",
+}
+
+_PLACEHOLDER_RE = re.compile(r"\$\{([A-Za-z_][A-Za-z0-9_]*)\}")
+_VALID_ROLES = frozenset(get_args(MessageRole))
+_VALID_STREAMS = frozenset(get_args(MessageStream))
+
+
+@dataclass
+class MessageTurn:
+    """A single chat-style turn in a recipe template.
+
+    ``content`` may be a plain string, a list of HF-style multimodal blocks, or
+    ``None`` when ``tool_calls_from`` supplies tool-call payloads instead.
+    ``stream`` tags the turn for downstream filtering, ``target`` flags it as a
+    training target, and ``if_present`` skips the turn when the named binding
+    resolves to ``None``.
+    """
+
+    role: MessageRole
+    content: str | list[dict[str, Any]] | None = None
+    stream: MessageStream | None = None
+    target: bool = False
+    if_present: str | None = None
+    tool_calls_from: str | None = None
+
+    def __post_init__(self) -> None:
+        """Validate role, stream, and content after dataclass construction."""
+        if self.role not in _VALID_ROLES:
+            raise ValueError(f"Unsupported message role: {self.role!r}")
+        if self.stream is not None and self.stream not in _VALID_STREAMS:
+            raise ValueError(f"Unsupported message stream: {self.stream!r}")
+        if self.content is None and self.tool_calls_from is None:
+            raise ValueError("MessageTurn.content is required unless tool_calls_from is set.")
+        if self.content is not None and not isinstance(self.content, (str, list)):
+            raise TypeError("MessageTurn.content must be a string, a list of HF-style blocks, or None.")
+        if isinstance(self.content, list):
+            for block in self.content:
+                if not isinstance(block, dict) or "type" not in block:
+                    raise ValueError(
+                        "Multimodal content blocks must be HF-style dictionaries with a type key."
+                    )
+
+    @classmethod
+    def from_dict(cls, data: dict[str, Any]) -> MessageTurn:
+        """Construct a :class:`MessageTurn` from a plain dictionary."""
+        return cls(**data)
+
+
+@dataclass
+class TrainingRecipe:
+    """A recipe describing how to render training samples from language rows.
+
+    A recipe is either a *message recipe* (``messages`` plus optional
+    ``bindings``) or a *blend recipe* (``blend`` mapping names to weighted
+    sub-recipes). ``weight`` is only meaningful inside a blend.
+    """
+
+    messages: list[MessageTurn] | None = None
+    bindings: dict[str, str] | None = None
+    blend: dict[str, TrainingRecipe] | None = None
+    weight: float | None = None
+
+    def __post_init__(self) -> None:
+        """Validate that exactly one of ``messages`` or ``blend`` is set."""
+        if self.messages is not None and self.blend is not None:
+            raise ValueError("TrainingRecipe must set only one of messages or blend.")
+        if self.messages is None and self.blend is None:
+            raise ValueError("TrainingRecipe must set one of messages or blend.")
+
+        if self.messages is not None:
+            self._validate_message_recipe()
+        if self.blend is not None:
+            self._validate_blend_recipe()
+
+    @classmethod
+    def from_dict(cls, data: dict[str, Any]) -> TrainingRecipe:
+        """Construct a :class:`TrainingRecipe` from a nested dictionary."""
+        data = dict(data)
+        if data.get("messages") is not None:
+            data["messages"] = [
+                turn if isinstance(turn, MessageTurn) else MessageTurn.from_dict(turn)
+                for turn in data["messages"]
+            ]
+        if data.get("blend") is not None:
+            data["blend"] = {
+                name: recipe if isinstance(recipe, TrainingRecipe) else cls.from_dict(recipe)
+                for name, recipe in data["blend"].items()
+            }
+        return cls(**data)
+
+    @classmethod
+    def from_yaml(cls, path: str | Path) -> TrainingRecipe:
+        """Load a :class:`TrainingRecipe` from a YAML file at ``path``."""
+        import yaml  # type: ignore[import-untyped]
+
+        with open(path) as f:
+            data = yaml.safe_load(f)
+        if not isinstance(data, dict):
+            raise ValueError(f"Recipe YAML must contain a mapping at the top level: {path}")
+        return cls.from_dict(data)
+
+    def _validate_message_recipe(self) -> None:
+        """Ensure every templated binding is known and at least one turn is a target."""
+        assert self.messages is not None
+        known_bindings = set(DEFAULT_BINDINGS) | set(self.bindings or {}) | {"task"}
+
+        for turn in self.messages:
+            missing = self._referenced_bindings(turn) - known_bindings
+            if missing:
+                raise ValueError(f"MessageTurn references unknown binding(s): {sorted(missing)}")
+
+        if not any(turn.target for turn in self.messages):
+            raise ValueError("Message recipes must contain at least one target turn.")
+
+    def _validate_blend_recipe(self) -> None:
+        """Ensure each blend component is a non-empty, weighted message recipe."""
+        assert self.blend is not None
+        if not self.blend:
+            raise ValueError("Blend recipes must contain at least one component.")
+
+        for name, recipe in self.blend.items():
+            if recipe.blend is not None:
+                raise ValueError(f"Blend component {name!r} cannot itself define a blend.")
+            if recipe.messages is None:
+                raise ValueError(f"Blend component {name!r} must define messages.")
+            if recipe.weight is None:
+                raise ValueError(f"Blend component {name!r} must define weight.")
+            if recipe.weight <= 0:
+                raise ValueError(f"Blend component {name!r} must have a positive weight.")
+
+    def _referenced_bindings(self, turn: MessageTurn) -> set[str]:
+        """Return the binding names that ``turn`` references via placeholders or attributes."""
+        names: set[str] = set()
+        if turn.if_present is not None:
+            names.add(turn.if_present)
+        if turn.tool_calls_from is not None:
+            names.add(turn.tool_calls_from)
+        names.update(_placeholders_in_content(turn.content))
+        return names
+
+
+def _placeholders_in_content(content: str | list[dict[str, Any]] | None) -> set[str]:
+    """Return the set of ``${name}`` placeholders found anywhere in ``content``."""
+    if content is None:
+        return set()
+    if isinstance(content, str):
+        return set(_PLACEHOLDER_RE.findall(content))
+
+    names: set[str] = set()
+    for block in content:
+        for value in block.values():
+            if isinstance(value, str):
+                names.update(_PLACEHOLDER_RE.findall(value))
+    return names
+
+
+def load_recipe(path: str | Path) -> TrainingRecipe:
+    """Load a :class:`TrainingRecipe` from a YAML file at ``path``."""
+    return TrainingRecipe.from_yaml(path)

src/lerobot/configs/recipes/pi05_hirobot.yaml

@@ -0,0 +1,47 @@
+blend:
+
+  memory_update:
+    weight: 0.10
+    bindings:
+      prior_memory: "nth_prev(style=memory, offset=1)"
+      current_memory: "emitted_at(t, style=memory)"
+      completed_subtask: "nth_prev(style=subtask, offset=1)"
+    messages:
+      - {role: user, content: "${task}", stream: high_level}
+      - {role: assistant, content: "Previous memory: ${prior_memory}", stream: high_level, if_present: prior_memory}
+      - {role: user, content: "Completed subtask: ${completed_subtask}", stream: high_level, if_present: completed_subtask}
+      - {role: assistant, content: "${current_memory}", stream: high_level, target: true, if_present: current_memory}
+
+  user_interjection_response:
+    weight: 0.16
+    bindings:
+      prior_plan: "nth_prev(style=plan, offset=1)"
+      current_plan: "emitted_at(t, style=plan)"
+      interjection: "emitted_at(t, style=interjection)"
+      speech: "emitted_at(t, role=assistant, tool_name=say)"
+    messages:
+      - {role: user, content: "${task}", stream: high_level}
+      - {role: assistant, content: "Previous plan:\n${prior_plan}", stream: high_level, if_present: prior_plan}
+      - {role: user, content: "${interjection}", stream: high_level, if_present: interjection}
+      - {role: assistant, content: "${current_plan}", stream: high_level, target: true, if_present: current_plan, tool_calls_from: speech}
+
+  high_level_subtask:
+    weight: 0.15
+    bindings:
+      next_subtask: "nth_next(style=subtask, offset=1)"
+    messages:
+      - {role: user, content: "${task}\nPlan: ${plan}\nMemory: ${memory}", stream: high_level}
+      - {role: user, content: "Current subtask: ${subtask}", stream: high_level, if_present: subtask}
+      - {role: assistant, content: "${next_subtask}", stream: high_level, target: true}
+
+  low_level_execution:
+    weight: 0.35
+    messages:
+      - {role: user, content: "${task}\nPlan: ${plan}\nMemory: ${memory}", stream: high_level}
+      - {role: assistant, content: "${subtask}", stream: low_level, target: true}
+
+  ask_vqa:
+    weight: 0.20
+    messages:
+      - {role: user, content: "${vqa_query}", stream: high_level, if_present: vqa_query}
+      - {role: assistant, content: "${vqa}", stream: high_level, target: true, if_present: vqa}

src/lerobot/configs/rewards.py

@@ -1,163 +0,0 @@
-# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-import abc
-import builtins
-import json
-import logging
-import os
-import tempfile
-from dataclasses import dataclass, field
-from pathlib import Path
-from typing import Any, TypeVar
-
-import draccus
-from huggingface_hub import hf_hub_download
-from huggingface_hub.constants import CONFIG_NAME
-from huggingface_hub.errors import HfHubHTTPError
-
-from lerobot.configs.types import PolicyFeature
-from lerobot.optim.optimizers import OptimizerConfig
-from lerobot.optim.schedulers import LRSchedulerConfig
-from lerobot.utils.device_utils import auto_select_torch_device, is_torch_device_available
-from lerobot.utils.hub import HubMixin
-
-T = TypeVar("T", bound="RewardModelConfig")
-logger = logging.getLogger(__name__)
-
-
-@dataclass
-class RewardModelConfig(draccus.ChoiceRegistry, HubMixin, abc.ABC):
-    """Base configuration for reward models.
-
-    Args:
-    input_features: A dictionary defining the PolicyFeature of the input data for the reward. The key represents
-        the input data name, and the value is PolicyFeature, which consists of FeatureType and shape attributes.
-    output_features: A dictionary defining the PolicyFeature of the output data for the reward. The key represents
-        the output data name, and the value is PolicyFeature, which consists of FeatureType and shape attributes.
-    """
-
-    # Reuses PolicyFeature
-    input_features: dict[str, PolicyFeature] = field(default_factory=dict)
-    output_features: dict[str, PolicyFeature] = field(default_factory=dict)
-
-    device: str | None = None
-
-    pretrained_path: str | None = None
-
-    push_to_hub: bool = False
-    repo_id: str | None = None
-
-    # Hub metadata
-    license: str | None = None
-    tags: list[str] | None = None
-    private: bool | None = None
-
-    def __post_init__(self) -> None:
-        if not self.device or not is_torch_device_available(self.device):
-            auto_device = auto_select_torch_device()
-            logger.warning(f"Device '{self.device}' is not available. Switching to '{auto_device}'.")
-            self.device = auto_device.type
-
-    @property
-    def type(self) -> str:
-        choice_name = self.get_choice_name(self.__class__)
-        if not isinstance(choice_name, str):
-            raise TypeError(f"Expected string from get_choice_name, got {type(choice_name)}")
-        return choice_name
-
-    @property
-    def observation_delta_indices(self) -> list | None:  # type: ignore[type-arg]
-        return None
-
-    @property
-    def action_delta_indices(self) -> list | None:  # type: ignore[type-arg]
-        return None
-
-    @property
-    def reward_delta_indices(self) -> list | None:  # type: ignore[type-arg]
-        return None
-
-    @abc.abstractmethod
-    def get_optimizer_preset(self) -> OptimizerConfig:
-        raise NotImplementedError
-
-    def get_scheduler_preset(self) -> LRSchedulerConfig | None:
-        return None
-
-    def validate_features(self) -> None:
-        pass
-
-    def _save_pretrained(self, save_directory: Path) -> None:
-        with open(save_directory / CONFIG_NAME, "w") as f, draccus.config_type("json"):
-            draccus.dump(self, f, indent=4)
-
-    @classmethod
-    def from_pretrained(
-        cls: builtins.type[T],
-        pretrained_name_or_path: str | Path,
-        *,
-        force_download: bool = False,
-        resume_download: bool | None = None,
-        proxies: dict[Any, Any] | None = None,
-        token: str | bool | None = None,
-        cache_dir: str | Path | None = None,
-        local_files_only: bool = False,
-        revision: str | None = None,
-        **reward_kwargs: Any,
-    ) -> T:
-        model_id = str(pretrained_name_or_path)
-        config_file: str | None = None
-        if Path(model_id).is_dir():
-            if CONFIG_NAME in os.listdir(model_id):
-                config_file = os.path.join(model_id, CONFIG_NAME)
-            else:
-                logger.error(f"{CONFIG_NAME} not found in {Path(model_id).resolve()}")
-        else:
-            try:
-                config_file = hf_hub_download(
-                    repo_id=model_id,
-                    filename=CONFIG_NAME,
-                    revision=revision,
-                    cache_dir=cache_dir,
-                    force_download=force_download,
-                    proxies=proxies,
-                    resume_download=resume_download,
-                    token=token,
-                    local_files_only=local_files_only,
-                )
-            except HfHubHTTPError as e:
-                raise FileNotFoundError(
-                    f"{CONFIG_NAME} not found on the HuggingFace Hub in {model_id}"
-                ) from e
-
-        if config_file is None:
-            raise FileNotFoundError(f"{CONFIG_NAME} not found in {model_id}")
-
-        # HACK: Parse the original config to get the config subclass, so that we can
-        # apply cli overrides.
-        with draccus.config_type("json"):
-            orig_config = draccus.parse(cls, config_file, args=[])
-
-        with open(config_file) as f:
-            config = json.load(f)
-
-        config.pop("type", None)
-        with tempfile.NamedTemporaryFile("w+", delete=False, suffix=".json") as f:
-            json.dump(config, f)
-            config_file = f.name
-
-        cli_overrides = reward_kwargs.pop("cli_overrides", [])
-        with draccus.config_type("json"):
-            return draccus.parse(orig_config.__class__, config_file, args=cli_overrides)

src/lerobot/configs/train.py

@@ -13,9 +13,7 @@
 # limitations under the License.
 import builtins
 import datetime as dt
-import json
 import os
-import tempfile
 from dataclasses import dataclass, field
 from pathlib import Path
 from typing import Any
@@ -28,57 +26,18 @@ from lerobot import envs
 from lerobot.configs import parser
 from lerobot.optim import LRSchedulerConfig, OptimizerConfig
 from lerobot.utils.hub import HubMixin
-from lerobot.utils.sample_weighting import SampleWeightingConfig
 
 from .default import DatasetConfig, EvalConfig, PeftConfig, WandBConfig
 from .policies import PreTrainedConfig
-from .rewards import RewardModelConfig
 
 TRAIN_CONFIG_NAME = "train_config.json"
 
 
-def _migrate_legacy_rabc_fields(config: dict[str, Any]) -> dict[str, Any] | None:
-    """Return migrated payload for legacy RA-BC fields, or None when no migration is needed."""
-    legacy_fields = (
-        "use_rabc",
-        "rabc_progress_path",
-        "rabc_kappa",
-        "rabc_epsilon",
-        "rabc_head_mode",
-    )
-    if not any(key in config for key in legacy_fields):
-        return None
-
-    migrated_config = dict(config)
-    use_rabc = bool(migrated_config.pop("use_rabc", False))
-    rabc_progress_path = migrated_config.pop("rabc_progress_path", None)
-    rabc_kappa = migrated_config.pop("rabc_kappa", None)
-    rabc_epsilon = migrated_config.pop("rabc_epsilon", None)
-    rabc_head_mode = migrated_config.pop("rabc_head_mode", None)
-
-    # New configs may already define sample_weighting explicitly. In that case,
-    # legacy fields are ignored after being stripped from the payload.
-    if migrated_config.get("sample_weighting") is None and use_rabc:
-        sample_weighting: dict[str, Any] = {"type": "rabc"}
-        if rabc_progress_path is not None:
-            sample_weighting["progress_path"] = rabc_progress_path
-        if rabc_kappa is not None:
-            sample_weighting["kappa"] = rabc_kappa
-        if rabc_epsilon is not None:
-            sample_weighting["epsilon"] = rabc_epsilon
-        if rabc_head_mode is not None:
-            sample_weighting["head_mode"] = rabc_head_mode
-        migrated_config["sample_weighting"] = sample_weighting
-
-    return migrated_config
-
-
 @dataclass
 class TrainPipelineConfig(HubMixin):
     dataset: DatasetConfig
     env: envs.EnvConfig | None = None
     policy: PreTrainedConfig | None = None
-    reward_model: RewardModelConfig | None = None
     # Set `dir` to where you would like to save all of the run outputs. If you run another training session
     # with the same value for `dir` its contents will be overwritten unless you set `resume` to true.
     output_dir: Path | None = None
@@ -113,41 +72,27 @@ class TrainPipelineConfig(HubMixin):
     wandb: WandBConfig = field(default_factory=WandBConfig)
     peft: PeftConfig | None = None
 
-    # Sample weighting configuration (e.g., for RA-BC training)
-    sample_weighting: SampleWeightingConfig | None = None
+    # RA-BC (Reward-Aligned Behavior Cloning) parameters
+    use_rabc: bool = False  # Enable reward-weighted training
+    rabc_progress_path: str | None = None  # Path to precomputed SARM progress parquet file
+    rabc_kappa: float = 0.01  # Hard threshold for high-quality samples
+    rabc_epsilon: float = 1e-6  # Small constant for numerical stability
+    rabc_head_mode: str | None = "sparse"  # For dual-head models: "sparse" or "dense"
 
     # Rename map for the observation to override the image and state keys
     rename_map: dict[str, str] = field(default_factory=dict)
     checkpoint_path: Path | None = field(init=False, default=None)
 
-    @property
-    def is_reward_model_training(self) -> bool:
-        """True when the config targets a reward model rather than a policy."""
-        return self.reward_model is not None
-
-    @property
-    def trainable_config(self) -> PreTrainedConfig | RewardModelConfig:
-        """Return whichever config (policy or reward_model) is active."""
-        if self.is_reward_model_training:
-            return self.reward_model  # type: ignore[return-value]
-        return self.policy  # type: ignore[return-value]
-
     def validate(self) -> None:
         # HACK: We parse again the cli args here to get the pretrained paths if there was some.
         policy_path = parser.get_path_arg("policy")
-        reward_model_path = parser.get_path_arg("reward_model")
-
-        if reward_model_path:
-            cli_overrides = parser.get_cli_overrides("reward_model")
-            self.reward_model = RewardModelConfig.from_pretrained(
-                reward_model_path, cli_overrides=cli_overrides
-            )
-            self.reward_model.pretrained_path = str(Path(reward_model_path))
-        elif policy_path:
+        if policy_path:
+            # Only load the policy config
             cli_overrides = parser.get_cli_overrides("policy")
             self.policy = PreTrainedConfig.from_pretrained(policy_path, cli_overrides=cli_overrides)
             self.policy.pretrained_path = Path(policy_path)
         elif self.resume:
+            # The entire train config is already loaded, we just need to get the checkpoint dir
             config_path = parser.parse_arg("config_path")
             if not config_path:
                 raise ValueError(
@@ -163,22 +108,18 @@ class TrainPipelineConfig(HubMixin):
             policy_dir = Path(config_path).parent
             if self.policy is not None:
                 self.policy.pretrained_path = policy_dir
-            if self.reward_model is not None:
-                self.reward_model.pretrained_path = str(policy_dir)
             self.checkpoint_path = policy_dir.parent
 
-        if self.policy is None and self.reward_model is None:
+        if self.policy is None:
             raise ValueError(
-                "Neither policy nor reward_model is configured. "
-                "Please specify one with `--policy.path` or `--reward_model.path`."
+                "Policy is not configured. Please specify a pretrained policy with `--policy.path`."
             )
 
-        active_cfg = self.trainable_config
         if not self.job_name:
             if self.env is None:
-                self.job_name = f"{active_cfg.type}"
+                self.job_name = f"{self.policy.type}"
             else:
-                self.job_name = f"{self.env.type}_{active_cfg.type}"
+                self.job_name = f"{self.env.type}_{self.policy.type}"
 
         if not self.resume and isinstance(self.output_dir, Path) and self.output_dir.is_dir():
             raise FileExistsError(
@@ -196,16 +137,26 @@ class TrainPipelineConfig(HubMixin):
         if not self.use_policy_training_preset and (self.optimizer is None or self.scheduler is None):
             raise ValueError("Optimizer and Scheduler must be set when the policy presets are not used.")
         elif self.use_policy_training_preset and not self.resume:
-            self.optimizer = active_cfg.get_optimizer_preset()
-            self.scheduler = active_cfg.get_scheduler_preset()
+            self.optimizer = self.policy.get_optimizer_preset()
+            self.scheduler = self.policy.get_scheduler_preset()
 
-        if hasattr(active_cfg, "push_to_hub") and active_cfg.push_to_hub and not active_cfg.repo_id:
-            raise ValueError("'repo_id' argument missing. Please specify it to push the model to the hub.")
+        if self.policy.push_to_hub and not self.policy.repo_id:
+            raise ValueError(
+                "'policy.repo_id' argument missing. Please specify it to push the model to the hub."
+            )
+
+        if self.use_rabc and not self.rabc_progress_path:
+            # Auto-detect from dataset path
+            repo_id = self.dataset.repo_id
+            if self.dataset.root:
+                self.rabc_progress_path = str(Path(self.dataset.root) / "sarm_progress.parquet")
+            else:
+                self.rabc_progress_path = f"hf://datasets/{repo_id}/sarm_progress.parquet"
 
     @classmethod
     def __get_path_fields__(cls) -> list[str]:
-        """Keys for draccus pretrained-path loading."""
-        return ["policy", "reward_model"]
+        """This enables the parser to load config from the policy using `--policy.path=local/dir`"""
+        return ["policy"]
 
     def to_dict(self) -> dict[str, Any]:
         return draccus.encode(self)  # type: ignore[no-any-return]  # because of the third-party library draccus uses Any as the return type
@@ -256,15 +207,6 @@ class TrainPipelineConfig(HubMixin):
                 ) from e
 
         cli_args = kwargs.pop("cli_args", [])
-        if config_file is not None:
-            with open(config_file) as f:
-                config = json.load(f)
-            migrated_config = _migrate_legacy_rabc_fields(config)
-            if migrated_config is not None:
-                with tempfile.NamedTemporaryFile("w+", delete=False, suffix=".json") as f:
-                    json.dump(migrated_config, f)
-                    config_file = f.name
-
         with draccus.config_type("json"):
             return draccus.parse(cls, config_file, args=cli_args)
 

src/lerobot/datasets/__init__.py

@@ -37,24 +37,21 @@ from .dataset_tools import (
 from .factory import make_dataset, resolve_delta_timestamps
 from .image_writer import safe_stop_image_writer
 from .io_utils import load_episodes, write_stats
+from .language import (
+    EVENT_ONLY_STYLES,
+    LANGUAGE_EVENTS,
+    LANGUAGE_PERSISTENT,
+    PERSISTENT_STYLES,
+    STYLE_REGISTRY,
+    column_for_style,
+)
 from .lerobot_dataset import LeRobotDataset
 from .multi_dataset import MultiLeRobotDataset
 from .pipeline_features import aggregate_pipeline_dataset_features, create_initial_features
-from .pyav_utils import (
-    check_video_encoder_config_pyav,
-    detect_available_encoders_pyav,
-    get_codec,
-)
 from .sampler import EpisodeAwareSampler
 from .streaming_dataset import StreamingLeRobotDataset
 from .utils import DEFAULT_EPISODES_PATH, create_lerobot_dataset_card
-from .video_utils import (
-    DepthEncoderConfig,
-    VideoEncoderConfig,
-    VideoEncodingManager,
-    camera_encoder_defaults,
-    depth_encoder_defaults,
-)
+from .video_utils import VideoEncodingManager
 
 # NOTE: Low-level I/O functions (cast_stats_to_numpy, get_parquet_file_size_in_mb, etc.)
 # and legacy migration constants are intentionally NOT re-exported here.
@@ -64,27 +61,26 @@ __all__ = [
     "CODEBASE_VERSION",
     "DEFAULT_EPISODES_PATH",
     "DEFAULT_QUANTILES",
+    "EVENT_ONLY_STYLES",
     "EpisodeAwareSampler",
+    "LANGUAGE_EVENTS",
+    "LANGUAGE_PERSISTENT",
     "LeRobotDataset",
     "LeRobotDatasetMetadata",
     "MultiLeRobotDataset",
+    "PERSISTENT_STYLES",
+    "STYLE_REGISTRY",
     "StreamingLeRobotDataset",
-    "DepthEncoderConfig",
-    "VideoEncoderConfig",
     "VideoEncodingManager",
-    "camera_encoder_defaults",
-    "depth_encoder_defaults",
     "add_features",
     "aggregate_datasets",
     "aggregate_pipeline_dataset_features",
     "aggregate_stats",
-    "check_video_encoder_config_pyav",
     "convert_image_to_video_dataset",
     "create_initial_features",
     "create_lerobot_dataset_card",
+    "column_for_style",
     "delete_episodes",
-    "detect_available_encoders_pyav",
-    "get_codec",
     "get_feature_stats",
     "load_episodes",
     "make_dataset",

src/lerobot/datasets/aggregate.py

@@ -97,8 +97,8 @@ def update_data_df(df, src_meta, dst_meta):
         pd.DataFrame: Updated DataFrame with adjusted indices.
     """
 
-    df["episode_index"] = df["episode_index"] + dst_meta.info.total_episodes
-    df["index"] = df["index"] + dst_meta.info.total_frames
+    df["episode_index"] = df["episode_index"] + dst_meta.info["total_episodes"]
+    df["index"] = df["index"] + dst_meta.info["total_frames"]
 
     src_task_names = src_meta.tasks.index.take(df["task_index"].to_numpy())
     df["task_index"] = dst_meta.tasks.loc[src_task_names, "task_index"].to_numpy()
@@ -225,9 +225,9 @@ def update_meta_data(
         # Clean up temporary columns
         df = df.drop(columns=["_orig_chunk", "_orig_file"])
 
-    df["dataset_from_index"] = df["dataset_from_index"] + dst_meta.info.total_frames
-    df["dataset_to_index"] = df["dataset_to_index"] + dst_meta.info.total_frames
-    df["episode_index"] = df["episode_index"] + dst_meta.info.total_episodes
+    df["dataset_from_index"] = df["dataset_from_index"] + dst_meta.info["total_frames"]
+    df["dataset_to_index"] = df["dataset_to_index"] + dst_meta.info["total_frames"]
+    df["episode_index"] = df["episode_index"] + dst_meta.info["total_episodes"]
 
     return df
 
@@ -237,8 +237,8 @@ def aggregate_datasets(
     aggr_repo_id: str,
     roots: list[Path] | None = None,
     aggr_root: Path | None = None,
-    data_files_size_in_mb: int | None = None,
-    video_files_size_in_mb: int | None = None,
+    data_files_size_in_mb: float | None = None,
+    video_files_size_in_mb: float | None = None,
     chunk_size: int | None = None,
 ):
     """Aggregates multiple LeRobot datasets into a single unified dataset.
@@ -313,8 +313,8 @@ def aggregate_datasets(
         # to avoid interference between different source datasets
         data_idx.pop("src_to_dst", None)
 
-        dst_meta.info.total_episodes += src_meta.total_episodes
-        dst_meta.info.total_frames += src_meta.total_frames
+        dst_meta.info["total_episodes"] += src_meta.total_episodes
+        dst_meta.info["total_frames"] += src_meta.total_frames
 
     finalize_aggregation(dst_meta, all_metadata)
     logging.info("Aggregation complete.")
@@ -332,6 +332,7 @@ def aggregate_videos(src_meta, dst_meta, videos_idx, video_files_size_in_mb, chu
         videos_idx: Dictionary tracking video chunk and file indices.
         video_files_size_in_mb: Maximum size for video files in MB (defaults to DEFAULT_VIDEO_FILE_SIZE_IN_MB)
         chunk_size: Maximum number of files per chunk (defaults to DEFAULT_CHUNK_SIZE)
+
     Returns:
         dict: Updated videos_idx with current chunk and file indices.
     """
@@ -416,7 +417,6 @@ def aggregate_videos(src_meta, dst_meta, videos_idx, video_files_size_in_mb, chu
                 concatenate_video_files(
                     [dst_path, src_path],
                     dst_path,
-                    compatibility_check=True,
                 )
                 # Update duration of this destination file
                 dst_file_durations[dst_key] = current_dst_duration + src_duration
@@ -640,10 +640,14 @@ def finalize_aggregation(aggr_meta, all_metadata):
     write_tasks(aggr_meta.tasks, aggr_meta.root)
 
     logging.info("write info")
-    aggr_meta.info.total_tasks = len(aggr_meta.tasks)
-    aggr_meta.info.total_episodes = sum(m.total_episodes for m in all_metadata)
-    aggr_meta.info.total_frames = sum(m.total_frames for m in all_metadata)
-    aggr_meta.info.splits = {"train": f"0:{sum(m.total_episodes for m in all_metadata)}"}
+    aggr_meta.info.update(
+        {
+            "total_tasks": len(aggr_meta.tasks),
+            "total_episodes": sum(m.total_episodes for m in all_metadata),
+            "total_frames": sum(m.total_frames for m in all_metadata),
+            "splits": {"train": f"0:{sum(m.total_episodes for m in all_metadata)}"},
+        }
+    )
     write_info(aggr_meta.info, aggr_meta.root)
 
     logging.info("write stats")

src/lerobot/datasets/compute_stats.py

@@ -512,7 +512,7 @@ def compute_episode_stats(
 
     ep_stats = {}
     for key, data in episode_data.items():
-        if features[key]["dtype"] == "string":
+        if features[key]["dtype"] in {"string", "language"}:
             continue
 
         if features[key]["dtype"] in ["image", "video"]:

src/lerobot/datasets/dataset_metadata.py

@@ -34,21 +34,22 @@ from .io_utils import (
     load_episodes,
     load_info,
     load_stats,
-    load_subtasks,
     load_tasks,
     write_info,
+    write_json,
     write_stats,
     write_tasks,
 )
 from .utils import (
     DEFAULT_EPISODES_PATH,
+    INFO_PATH,
     check_version_compatibility,
     get_safe_version,
     has_legacy_hub_download_metadata,
     is_valid_version,
     update_chunk_file_indices,
 )
-from .video_utils import VideoEncoderConfig, get_video_info
+from .video_utils import get_video_info
 
 CODEBASE_VERSION = "v3.0"
 
@@ -175,7 +176,6 @@ class LeRobotDatasetMetadata:
         self.info = load_info(self.root)
         check_version_compatibility(self.repo_id, self._version, CODEBASE_VERSION)
         self.tasks = load_tasks(self.root)
-        self.subtasks = load_subtasks(self.root)
         self.episodes = load_episodes(self.root)
         self.stats = load_stats(self.root)
 
@@ -226,7 +226,7 @@ class LeRobotDatasetMetadata:
     @property
     def _version(self) -> packaging.version.Version:
         """Codebase version used to create this dataset."""
-        return packaging.version.parse(self.info.codebase_version)
+        return packaging.version.parse(self.info["codebase_version"])
 
     def get_data_file_path(self, ep_index: int) -> Path:
         """Return the relative parquet file path for the given episode index.
@@ -281,27 +281,27 @@ class LeRobotDatasetMetadata:
     @property
     def data_path(self) -> str:
         """Formattable string for the parquet files."""
-        return self.info.data_path
+        return self.info["data_path"]
 
     @property
     def video_path(self) -> str | None:
         """Formattable string for the video files."""
-        return self.info.video_path
+        return self.info["video_path"]
 
     @property
     def robot_type(self) -> str | None:
         """Robot type used in recording this dataset."""
-        return self.info.robot_type
+        return self.info["robot_type"]
 
     @property
     def fps(self) -> int:
         """Frames per second used during data collection."""
-        return self.info.fps
+        return self.info["fps"]
 
     @property
     def features(self) -> dict[str, dict]:
         """All features contained in the dataset."""
-        return self.info.features
+        return self.info["features"]
 
     @property
     def image_keys(self) -> list[str]:
@@ -313,20 +313,6 @@ class LeRobotDatasetMetadata:
         """Keys to access visual modalities stored as videos."""
         return [key for key, ft in self.features.items() if ft["dtype"] == "video"]
 
-    @property
-    def depth_keys(self) -> list[str]:
-        """Keys to access depth-map modalities stored as videos.
-
-        A depth video key is a feature whose ``info`` dict carries
-        ``"video.is_depth_map": True`` (set either at creation time by the user
-        or after the first encoded episode by :meth:`update_video_info`).
-        """
-        return [
-            key
-            for key, ft in self.features.items()
-            if ft["dtype"] == "video" and ft.get("info", {}).get("video.is_depth_map", False)
-        ]
-
     @property
     def camera_keys(self) -> list[str]:
         """Keys to access visual modalities (regardless of their storage method)."""
@@ -345,32 +331,32 @@ class LeRobotDatasetMetadata:
     @property
     def total_episodes(self) -> int:
         """Total number of episodes available."""
-        return self.info.total_episodes
+        return self.info["total_episodes"]
 
     @property
     def total_frames(self) -> int:
         """Total number of frames saved in this dataset."""
-        return self.info.total_frames
+        return self.info["total_frames"]
 
     @property
     def total_tasks(self) -> int:
         """Total number of different tasks performed in this dataset."""
-        return self.info.total_tasks
+        return self.info["total_tasks"]
 
     @property
     def chunks_size(self) -> int:
         """Max number of files per chunk."""
-        return self.info.chunks_size
+        return self.info["chunks_size"]
 
     @property
     def data_files_size_in_mb(self) -> int:
         """Max size of data file in mega bytes."""
-        return self.info.data_files_size_in_mb
+        return self.info["data_files_size_in_mb"]
 
     @property
     def video_files_size_in_mb(self) -> int:
         """Max size of video file in mega bytes."""
-        return self.info.video_files_size_in_mb
+        return self.info["video_files_size_in_mb"]
 
     def get_task_index(self, task: str) -> int | None:
         """
@@ -514,48 +500,29 @@ class LeRobotDatasetMetadata:
         self._save_episode_metadata(episode_dict)
 
         # Update info
-        self.info.total_episodes += 1
-        self.info.total_frames += episode_length
-        self.info.total_tasks = len(self.tasks)
-        self.info.splits = {"train": f"0:{self.info.total_episodes}"}
+        self.info["total_episodes"] += 1
+        self.info["total_frames"] += episode_length
+        self.info["total_tasks"] = len(self.tasks)
+        self.info["splits"] = {"train": f"0:{self.info['total_episodes']}"}
 
         write_info(self.info, self.root)
 
         self.stats = aggregate_stats([self.stats, episode_stats]) if self.stats is not None else episode_stats
         write_stats(self.stats, self.root)
 
-    def update_video_info(
-        self,
-        video_key: str | None = None,
-        camera_encoder_config: VideoEncoderConfig | None = None,
-    ) -> None:
-        """Populate per-feature video info in ``info.json``.
-
+    def update_video_info(self, video_key: str | None = None) -> None:
+        """
         Warning: this function writes info from first episode videos, implicitly assuming that all videos have
         been encoded the same way. Also, this means it assumes the first episode exists.
-
-        Args:
-            video_key: If provided, only update this video key. Otherwise update
-                all video keys in the dataset.
-            camera_encoder_config: Encoder configuration used to produce the
-                videos. When provided, its fields are recorded as
-                ``video.<field>`` entries alongside the stream-derived
-                ``video.*`` entries (see :func:`get_video_info`).
         """
         if video_key is not None and video_key not in self.video_keys:
             raise ValueError(f"Video key {video_key} not found in dataset")
 
         video_keys = [video_key] if video_key is not None else self.video_keys
         for key in video_keys:
-            existing = self.features[key].get("info") or {}
-            # Repopulate when codec metadata is missing — preserves user-provided
-            # markers like ``video.is_depth_map`` while still recording stream
-            # info on the first episode.
-            if not existing or "video.codec" not in existing:
+            if not self.features[key].get("info", None):
                 video_path = self.root / self.video_path.format(video_key=key, chunk_index=0, file_index=0)
-                stream_info = get_video_info(video_path, camera_encoder_config=camera_encoder_config)
-                merged = {**existing, **stream_info}
-                self.info.features[key]["info"] = merged
+                self.info["features"][key]["info"] = get_video_info(video_path)
 
     def update_chunk_settings(
         self,
@@ -577,17 +544,17 @@ class LeRobotDatasetMetadata:
         if chunks_size is not None:
             if chunks_size <= 0:
                 raise ValueError(f"chunks_size must be positive, got {chunks_size}")
-            self.info.chunks_size = chunks_size
+            self.info["chunks_size"] = chunks_size
 
         if data_files_size_in_mb is not None:
             if data_files_size_in_mb <= 0:
                 raise ValueError(f"data_files_size_in_mb must be positive, got {data_files_size_in_mb}")
-            self.info.data_files_size_in_mb = data_files_size_in_mb
+            self.info["data_files_size_in_mb"] = data_files_size_in_mb
 
         if video_files_size_in_mb is not None:
             if video_files_size_in_mb <= 0:
                 raise ValueError(f"video_files_size_in_mb must be positive, got {video_files_size_in_mb}")
-            self.info.video_files_size_in_mb = video_files_size_in_mb
+            self.info["video_files_size_in_mb"] = video_files_size_in_mb
 
         # Update the info file on disk
         write_info(self.info, self.root)
@@ -666,7 +633,6 @@ class LeRobotDatasetMetadata:
         _validate_feature_names(features)
 
         obj.tasks = None
-        obj.subtasks = None
         obj.episodes = None
         obj.stats = None
         obj.info = create_empty_dataset_info(
@@ -684,7 +650,7 @@ class LeRobotDatasetMetadata:
                 f"Features contain video keys {obj.video_keys}, but 'use_videos' is set to False. "
                 "Either remove video features from the features dict, or set 'use_videos=True'."
             )
-        write_info(obj.info, obj.root)
+        write_json(obj.info, obj.root / INFO_PATH)
         obj.revision = None
         obj._pq_writer = None
         obj.latest_episode = None

src/lerobot/datasets/dataset_reader.py

@@ -32,13 +32,7 @@ from .io_utils import (
     hf_transform_to_torch,
     load_nested_dataset,
 )
-from .video_utils import decode_depth_frames, decode_video_frames
-from .depth_utils import (
-    DEFAULT_DEPTH_MIN, 
-    DEFAULT_DEPTH_MAX, 
-    DEFAULT_DEPTH_SHIFT, 
-    DEFAULT_DEPTH_USE_LOG,
-)
+from .video_utils import decode_video_frames
 
 
 class DatasetReader:
@@ -243,31 +237,17 @@ class DatasetReader:
         """
         ep = self._meta.episodes[ep_idx]
 
-        depth_keys = set(self._meta.depth_keys)
-
         def _decode_single(vid_key: str, query_ts: list[float]) -> tuple[str, torch.Tensor]:
             from_timestamp = ep[f"videos/{vid_key}/from_timestamp"]
             shifted_query_ts = [from_timestamp + ts for ts in query_ts]
             video_path = self.root / self._meta.get_video_file_path(ep_idx, vid_key)
-            if vid_key in depth_keys:
-                feature_info = self._meta.features[vid_key].get("info") or {}
-                frames = decode_depth_frames(
-                    video_path,
-                    shifted_query_ts,
-                    self._tolerance_s,
-                    depth_min=feature_info.get("video.depth_min", DEFAULT_DEPTH_MIN),
-                    depth_max=feature_info.get("video.depth_max", DEFAULT_DEPTH_MAX),
-                    shift=feature_info.get("video.shift", DEFAULT_DEPTH_SHIFT),
-                    use_log=feature_info.get("video.use_log", DEFAULT_DEPTH_USE_LOG),
-                )
-            else:
-                frames = decode_video_frames(
-                    video_path,
-                    shifted_query_ts,
-                    self._tolerance_s,
-                    self._video_backend,
-                    return_uint8=self._return_uint8,
-                )
+            frames = decode_video_frames(
+                video_path,
+                shifted_query_ts,
+                self._tolerance_s,
+                self._video_backend,
+                return_uint8=self._return_uint8,
+            )
             return vid_key, frames.squeeze(0)
 
         items = list(query_timestamps.items())
@@ -315,9 +295,4 @@ class DatasetReader:
         task_idx = item["task_index"].item()
         item["task"] = self._meta.tasks.iloc[task_idx].name
 
-        # add subtask information if available
-        if "subtask_index" in self._meta.features and self._meta.subtasks is not None:
-            subtask_idx = item["subtask_index"].item()
-            item["subtask"] = self._meta.subtasks.iloc[subtask_idx].name
-
         return item

src/lerobot/datasets/dataset_tools.py

@@ -62,7 +62,7 @@ from .utils import (
     DEFAULT_EPISODES_PATH,
     update_chunk_file_indices,
 )
-from .video_utils import VideoEncoderConfig, encode_video_frames, get_video_info
+from .video_utils import encode_video_frames, get_video_info
 
 
 def _load_episode_with_stats(src_dataset: LeRobotDataset, episode_idx: int) -> dict:
@@ -92,7 +92,6 @@ def delete_episodes(
     episode_indices: list[int],
     output_dir: str | Path | None = None,
     repo_id: str | None = None,
-    camera_encoder_config: VideoEncoderConfig | None = None,
 ) -> LeRobotDataset:
     """Delete episodes from a LeRobotDataset and create a new dataset.
 
@@ -101,7 +100,6 @@ def delete_episodes(
         episode_indices: List of episode indices to delete.
         output_dir: Root directory where the edited dataset will be stored. If not specified, defaults to $HF_LEROBOT_HOME/repo_id. Equivalent to new_root in EditDatasetConfig.
         repo_id: Edited dataset identifier. Equivalent to new_repo_id in EditDatasetConfig.
-        camera_encoder_config: Video encoder settings used when re-encoding video segments (default: :class:`VideoEncoderConfig()`).
     """
     if not episode_indices:
         raise ValueError("No episodes to delete")
@@ -134,7 +132,7 @@ def delete_episodes(
 
     video_metadata = None
     if dataset.meta.video_keys:
-        video_metadata = _copy_and_reindex_videos(dataset, new_meta, episode_mapping, camera_encoder_config)
+        video_metadata = _copy_and_reindex_videos(dataset, new_meta, episode_mapping)
 
     data_metadata = _copy_and_reindex_data(dataset, new_meta, episode_mapping)
 
@@ -156,7 +154,6 @@ def split_dataset(
     dataset: LeRobotDataset,
     splits: dict[str, float | list[int]],
     output_dir: str | Path | None = None,
-    camera_encoder_config: VideoEncoderConfig | None = None,
 ) -> dict[str, LeRobotDataset]:
     """Split a LeRobotDataset into multiple smaller datasets.
 
@@ -165,7 +162,6 @@ def split_dataset(
         splits: Either a dict mapping split names to episode indices, or a dict mapping
                 split names to fractions (must sum to <= 1.0).
         output_dir: Root directory where the split datasets will be stored. If not specified, defaults to $HF_LEROBOT_HOME/repo_id.
-        camera_encoder_config: Video encoder settings used when re-encoding video segments (default: :class:`VideoEncoderConfig()`).
 
     Examples:
       Split by specific episodes
@@ -226,9 +222,7 @@ def split_dataset(
 
         video_metadata = None
         if dataset.meta.video_keys:
-            video_metadata = _copy_and_reindex_videos(
-                dataset, new_meta, episode_mapping, camera_encoder_config
-            )
+            video_metadata = _copy_and_reindex_videos(dataset, new_meta, episode_mapping)
 
         data_metadata = _copy_and_reindex_data(dataset, new_meta, episode_mapping)
 
@@ -584,7 +578,8 @@ def _keep_episodes_from_video_with_av(
     output_path: Path,
     episodes_to_keep: list[tuple[int, int]],
     fps: float,
-    camera_encoder_config: VideoEncoderConfig | None = None,
+    vcodec: str = "libsvtav1",
+    pix_fmt: str = "yuv420p",
 ) -> None:
     """Keep only specified episodes from a video file using PyAV.
 
@@ -598,10 +593,9 @@ def _keep_episodes_from_video_with_av(
             Ranges are half-open intervals: [start_frame, end_frame), where start_frame
             is inclusive and end_frame is exclusive.
         fps: Frame rate of the video.
-        camera_encoder_config: Video encoder settings (default: :class:`VideoEncoderConfig()`).
+        vcodec: Video codec to use for encoding.
+        pix_fmt: Pixel format for output video.
     """
-    if camera_encoder_config is None:
-        camera_encoder_config = VideoEncoderConfig()
     from fractions import Fraction
 
     import av
@@ -625,12 +619,12 @@ def _keep_episodes_from_video_with_av(
 
     # Convert fps to Fraction for PyAV compatibility.
     fps_fraction = Fraction(fps).limit_denominator(1000)
-    v_out = out.add_stream(camera_encoder_config.vcodec, rate=fps_fraction)
+    v_out = out.add_stream(vcodec, rate=fps_fraction)
 
     # PyAV type stubs don't distinguish video streams from audio/subtitle streams.
     v_out.width = v_in.codec_context.width
     v_out.height = v_in.codec_context.height
-    v_out.pix_fmt = camera_encoder_config.pix_fmt
+    v_out.pix_fmt = pix_fmt
 
     # Set time_base to match the frame rate for proper timestamp handling.
     v_out.time_base = Fraction(1, int(fps))
@@ -693,7 +687,8 @@ def _copy_and_reindex_videos(
     src_dataset: LeRobotDataset,
     dst_meta: LeRobotDatasetMetadata,
     episode_mapping: dict[int, int],
-    camera_encoder_config: VideoEncoderConfig | None = None,
+    vcodec: str = "libsvtav1",
+    pix_fmt: str = "yuv420p",
 ) -> dict[int, dict]:
     """Copy and filter video files, only re-encoding files with deleted episodes.
 
@@ -705,13 +700,10 @@ def _copy_and_reindex_videos(
         src_dataset: Source dataset to copy from
         dst_meta: Destination metadata object
         episode_mapping: Mapping from old episode indices to new indices
-        camera_encoder_config: Video encoder settings used when re-encoding segments (default: :class:`VideoEncoderConfig()`).
 
     Returns:
         dict mapping episode index to its video metadata (chunk_index, file_index, timestamps)
     """
-    if camera_encoder_config is None:
-        camera_encoder_config = VideoEncoderConfig()
     if src_dataset.meta.episodes is None:
         src_dataset.meta.episodes = load_episodes(src_dataset.meta.root)
 
@@ -800,7 +792,8 @@ def _copy_and_reindex_videos(
                     dst_video_path,
                     episodes_to_keep_ranges,
                     src_dataset.meta.fps,
-                    camera_encoder_config,
+                    vcodec,
+                    pix_fmt,
                 )
 
                 cumulative_ts = 0.0
@@ -904,10 +897,14 @@ def _copy_and_reindex_episodes_metadata(
 
     dst_meta.finalize()
 
-    dst_meta.info.total_episodes = len(episode_mapping)
-    dst_meta.info.total_frames = total_frames
-    dst_meta.info.total_tasks = len(dst_meta.tasks) if dst_meta.tasks is not None else 0
-    dst_meta.info.splits = {"train": f"0:{len(episode_mapping)}"}
+    dst_meta.info.update(
+        {
+            "total_episodes": len(episode_mapping),
+            "total_frames": total_frames,
+            "total_tasks": len(dst_meta.tasks) if dst_meta.tasks is not None else 0,
+            "splits": {"train": f"0:{len(episode_mapping)}"},
+        }
+    )
     write_info(dst_meta.info, dst_meta.root)
 
     if not all_stats:
@@ -1072,20 +1069,21 @@ def _copy_episodes_metadata_and_stats(
     if episodes_dir.exists():
         shutil.copytree(episodes_dir, dst_episodes_dir, dirs_exist_ok=True)
 
-    dst_meta.info.total_episodes = src_dataset.meta.total_episodes
-    dst_meta.info.total_frames = src_dataset.meta.total_frames
-    dst_meta.info.total_tasks = src_dataset.meta.total_tasks
-    # Preserve original splits if available, otherwise create default
-    dst_meta.info.splits = (
-        src_dataset.meta.info.splits
-        if src_dataset.meta.info.splits
-        else {"train": f"0:{src_dataset.meta.total_episodes}"}
+    dst_meta.info.update(
+        {
+            "total_episodes": src_dataset.meta.total_episodes,
+            "total_frames": src_dataset.meta.total_frames,
+            "total_tasks": src_dataset.meta.total_tasks,
+            "splits": src_dataset.meta.info.get("splits", {"train": f"0:{src_dataset.meta.total_episodes}"}),
+        }
     )
 
     if dst_meta.video_keys and src_dataset.meta.video_keys:
         for key in dst_meta.video_keys:
             if key in src_dataset.meta.features:
-                dst_meta.info.features[key]["info"] = src_dataset.meta.info.features[key].get("info", {})
+                dst_meta.info["features"][key]["info"] = src_dataset.meta.info["features"][key].get(
+                    "info", {}
+                )
 
     write_info(dst_meta.info, dst_meta.root)
 
@@ -1271,7 +1269,11 @@ def _estimate_frame_size_via_calibration(
     episode_indices: list[int],
     temp_dir: Path,
     fps: int,
-    camera_encoder_config: VideoEncoderConfig,
+    vcodec: str,
+    pix_fmt: str,
+    g: int,
+    crf: int,
+    fast_decode: int,
     num_calibration_frames: int = 30,
 ) -> float:
     """Estimate MB per frame by encoding a small calibration sample.
@@ -1285,7 +1287,11 @@ def _estimate_frame_size_via_calibration(
         episode_indices: List of episode indices being processed.
         temp_dir: Temporary directory for calibration files.
         fps: Frames per second for video encoding.
-        camera_encoder_config: Video encoder settings used for calibration encoding.
+        vcodec: Video codec (libsvtav1, h264, hevc).
+        pix_fmt: Pixel format (yuv420p, etc.).
+        g: GOP size (group of pictures).
+        crf: Constant Rate Factor (quality).
+        fast_decode: Fast decode tuning parameter.
         num_calibration_frames: Number of frames to use for calibration (default: 30).
 
     Returns:
@@ -1321,7 +1327,11 @@ def _estimate_frame_size_via_calibration(
             imgs_dir=calibration_dir,
             video_path=calibration_video_path,
             fps=fps,
-            camera_encoder_config=camera_encoder_config,
+            vcodec=vcodec,
+            pix_fmt=pix_fmt,
+            g=g,
+            crf=crf,
+            fast_decode=fast_decode,
             overwrite=True,
         )
 
@@ -1515,7 +1525,7 @@ def modify_tasks(
     write_tasks(new_task_df, root)
 
     # Update info.json
-    dataset.meta.info.total_tasks = len(unique_tasks)
+    dataset.meta.info["total_tasks"] = len(unique_tasks)
     write_info(dataset.meta.info, root)
 
     # Reload metadata to reflect changes
@@ -1639,7 +1649,11 @@ def convert_image_to_video_dataset(
     dataset: LeRobotDataset,
     output_dir: Path | None = None,
     repo_id: str | None = None,
-    camera_encoder_config: VideoEncoderConfig | None = None,
+    vcodec: str = "libsvtav1",
+    pix_fmt: str = "yuv420p",
+    g: int = 2,
+    crf: int = 30,
+    fast_decode: int = 0,
     episode_indices: list[int] | None = None,
     num_workers: int = 4,
     max_episodes_per_batch: int | None = None,
@@ -1654,7 +1668,11 @@ def convert_image_to_video_dataset(
         dataset: The source LeRobot dataset with images
         output_dir: Root directory where the edited dataset will be stored. If not specified, defaults to $HF_LEROBOT_HOME/repo_id. Equivalent to new_root in EditDatasetConfig.
         repo_id: Edited dataset identifier. Equivalent to new_repo_id in EditDatasetConfig.
-        camera_encoder_config: Video encoder settings (default: :class:`VideoEncoderConfig()`).
+        vcodec: Video codec (default: libsvtav1)
+        pix_fmt: Pixel format (default: yuv420p)
+        g: Group of pictures size (default: 2)
+        crf: Constant rate factor (default: 30)
+        fast_decode: Fast decode tuning (default: 0)
         episode_indices: List of episode indices to convert (None = all episodes)
         num_workers: Number of threads for parallel processing (default: 4)
         max_episodes_per_batch: Maximum episodes per video batch to avoid memory issues (None = no limit)
@@ -1663,9 +1681,6 @@ def convert_image_to_video_dataset(
     Returns:
         New LeRobotDataset with images encoded as videos
     """
-    if camera_encoder_config is None:
-        camera_encoder_config = VideoEncoderConfig()
-
     # Check that it's an image dataset
     if len(dataset.meta.video_keys) > 0:
         raise ValueError(
@@ -1689,10 +1704,7 @@ def convert_image_to_video_dataset(
     logging.info(
         f"Converting {len(episode_indices)} episodes with {len(img_keys)} cameras from {dataset.repo_id}"
     )
-    logging.info(
-        f"Video codec: {camera_encoder_config.vcodec}, pixel format: {camera_encoder_config.pix_fmt}, "
-        f"GOP: {camera_encoder_config.g}, CRF: {camera_encoder_config.crf}"
-    )
+    logging.info(f"Video codec: {vcodec}, pixel format: {pix_fmt}, GOP: {g}, CRF: {crf}")
 
     # Create new features dict, converting image features to video features
     new_features = {}
@@ -1762,7 +1774,11 @@ def convert_image_to_video_dataset(
                 episode_indices=episode_indices,
                 temp_dir=temp_dir,
                 fps=fps,
-                camera_encoder_config=camera_encoder_config,
+                vcodec=vcodec,
+                pix_fmt=pix_fmt,
+                g=g,
+                crf=crf,
+                fast_decode=fast_decode,
             )
 
             logging.info(f"Processing camera: {img_key}")
@@ -1804,7 +1820,11 @@ def convert_image_to_video_dataset(
                     imgs_dir=imgs_dir,
                     video_path=video_path,
                     fps=fps,
-                    camera_encoder_config=camera_encoder_config,
+                    vcodec=vcodec,
+                    pix_fmt=pix_fmt,
+                    g=g,
+                    crf=crf,
+                    fast_decode=fast_decode,
                     overwrite=True,
                 )
 
@@ -1838,10 +1858,10 @@ def convert_image_to_video_dataset(
         episodes_df.to_parquet(episodes_path, index=False)
 
         # Update metadata info
-        new_meta.info.total_episodes = len(episode_indices)
-        new_meta.info.total_frames = sum(ep["length"] for ep in all_episode_metadata.values())
-        new_meta.info.total_tasks = dataset.meta.total_tasks
-        new_meta.info.splits = {"train": f"0:{len(episode_indices)}"}
+        new_meta.info["total_episodes"] = len(episode_indices)
+        new_meta.info["total_frames"] = sum(ep["length"] for ep in all_episode_metadata.values())
+        new_meta.info["total_tasks"] = dataset.meta.total_tasks
+        new_meta.info["splits"] = {"train": f"0:{len(episode_indices)}"}
 
         # Update video info for all image keys (now videos)
         # We need to manually set video info since update_video_info() checks video_keys first
@@ -1850,9 +1870,7 @@ def convert_image_to_video_dataset(
                 video_path = new_meta.root / new_meta.video_path.format(
                     video_key=img_key, chunk_index=0, file_index=0
                 )
-                new_meta.info.features[img_key]["info"] = get_video_info(
-                    video_path, camera_encoder_config=camera_encoder_config
-                )
+                new_meta.info["features"][img_key]["info"] = get_video_info(video_path)
 
         write_info(new_meta.info, new_meta.root)
 

src/lerobot/datasets/dataset_writer.py

@@ -46,19 +46,15 @@ from .io_utils import (
     write_info,
 )
 from .utils import (
-    DEFAULT_DEPTH_PATH,
     DEFAULT_EPISODES_PATH,
     DEFAULT_IMAGE_PATH,
     update_chunk_file_indices,
 )
 from .video_utils import (
-    DepthEncoderConfig,
     StreamingVideoEncoder,
-    VideoEncoderConfig,
     concatenate_video_files,
     encode_video_frames,
     get_video_duration_in_s,
-    is_depth_feature,
 )
 
 logger = logging.getLogger(__name__)
@@ -69,19 +65,14 @@ def _encode_video_worker(
     episode_index: int,
     root: Path,
     fps: int,
-    camera_encoder_config: VideoEncoderConfig | None = None,
+    vcodec: str = "libsvtav1",
     encoder_threads: int | None = None,
 ) -> Path:
     temp_path = Path(tempfile.mkdtemp(dir=root)) / f"{video_key}_{episode_index:03d}.mp4"
     fpath = DEFAULT_IMAGE_PATH.format(image_key=video_key, episode_index=episode_index, frame_index=0)
     img_dir = (root / fpath).parent
     encode_video_frames(
-        img_dir,
-        temp_path,
-        fps,
-        camera_encoder_config=camera_encoder_config,
-        encoder_threads=encoder_threads,
-        overwrite=True,
+        img_dir, temp_path, fps, vcodec=vcodec, overwrite=True, encoder_threads=encoder_threads
     )
     shutil.rmtree(img_dir)
     return temp_path
@@ -98,40 +89,33 @@ class DatasetWriter:
         self,
         meta: LeRobotDatasetMetadata,
         root: Path,
-        camera_encoder_config: VideoEncoderConfig,
+        vcodec: str,
         encoder_threads: int | None,
         batch_encoding_size: int,
         streaming_encoder: StreamingVideoEncoder | None = None,
         initial_frames: int = 0,
-        depth_encoder_config: DepthEncoderConfig | None = None,
     ):
-        """Initialize the writer with metadata, codec, and encoder config.
+        """Initialize the writer with metadata, codec, and encoding config.
 
         Args:
             meta: Dataset metadata instance (used for feature schema, chunk
                 settings, and episode persistence).
             root: Local dataset root directory.
-            camera_encoder_config: Video encoder settings applied to all cameras.
-            encoder_threads: Number of encoder threads (global). ``None``
-                lets the codec decide.
+            vcodec: Video codec for encoding (e.g. ``'libsvtav1'``, ``'h264'``).
+            encoder_threads: Threads per encoder instance. ``None`` for auto.
             batch_encoding_size: Number of episodes to accumulate before
                 batch-encoding videos.
             streaming_encoder: Optional pre-built :class:`StreamingVideoEncoder`
                 for real-time encoding. ``None`` disables streaming mode.
             initial_frames: Starting frame count (non-zero when resuming).
-            depth_encoder_config: Optional depth-map encoder config used in
-                place of ``camera_encoder_config`` for keys present in
-                ``meta.depth_keys``.
         """
         self._meta = meta
         self._root = root
-        self._camera_encoder_config = camera_encoder_config
-        self._depth_encoder_config = depth_encoder_config
+        self._vcodec = vcodec
         self._encoder_threads = encoder_threads
         self._batch_encoding_size = batch_encoding_size
         self._streaming_encoder = streaming_encoder
 
-
         # Writer state
         self.image_writer: AsyncImageWriter | None = None
         self.episode_buffer: dict = self._create_episode_buffer()
@@ -151,16 +135,8 @@ class DatasetWriter:
             ep_buffer[key] = current_ep_idx if key == "episode_index" else []
         return ep_buffer
 
-    def _is_depth_image_key(self, image_key: str) -> bool:
-        """Whether *image_key* is a depth feature stored as per-frame images."""
-        ft = self._meta.features.get(image_key)
-        if ft is None or ft.get("dtype") != "image":
-            return False
-        return is_depth_feature(ft.get("info") or {})
-
     def _get_image_file_path(self, episode_index: int, image_key: str, frame_index: int) -> Path:
-        path_template = DEFAULT_DEPTH_PATH if self._is_depth_image_key(image_key) else DEFAULT_IMAGE_PATH
-        fpath = path_template.format(
+        fpath = DEFAULT_IMAGE_PATH.format(
             image_key=image_key, episode_index=episode_index, frame_index=frame_index
         )
         return self._root / fpath
@@ -308,7 +284,7 @@ class DatasetWriter:
                             episode_index,
                             self._root,
                             self._meta.fps,
-                            self._camera_encoder_config,
+                            self._vcodec,
                             self._encoder_threads,
                         ): video_key
                         for video_key in self._meta.video_keys
@@ -519,13 +495,7 @@ class DatasetWriter:
 
         # Update video info (only needed when first episode is encoded)
         if episode_index == 0:
-            is_depth_key = video_key in set(self._meta.depth_keys)
-            cfg_for_info = (
-                self._depth_encoder_config
-                if is_depth_key and self._depth_encoder_config is not None
-                else self._camera_encoder_config
-            )
-            self._meta.update_video_info(video_key, camera_encoder_config=cfg_for_info)
+            self._meta.update_video_info(video_key)
             write_info(self._meta.info, self._meta.root)
 
         metadata = {
@@ -594,12 +564,7 @@ class DatasetWriter:
     def _encode_temporary_episode_video(self, video_key: str, episode_index: int) -> Path:
         """Use ffmpeg to convert frames stored as png into mp4 videos."""
         return _encode_video_worker(
-            video_key,
-            episode_index,
-            self._root,
-            self._meta.fps,
-            self._camera_encoder_config,
-            self._encoder_threads,
+            video_key, episode_index, self._root, self._meta.fps, self._vcodec, self._encoder_threads
         )
 
     def close_writer(self) -> None:

src/lerobot/datasets/depth_utils.py

@@ -1,189 +0,0 @@
-#!/usr/bin/env python
-
-# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-"""
-Depth encoding/decoding helpers for :class:`VideoEncoderConfig`.
-"""
-
-import math
-from typing import Literal
-
-import numpy as np
-import torch
-from numpy.typing import NDArray
-
-DEPTH_QUANT_BITS: int = 12
-DEPTH_QMAX: int = (1 << DEPTH_QUANT_BITS) - 1  # 4095
-_MM_PER_METRE: float = 1000.0
-_UINT16_MAX: int = 65535
-
-DEFAULT_DEPTH_MIN: float = 0.01
-DEFAULT_DEPTH_MAX: float = 10.0
-DEFAULT_DEPTH_SHIFT: float = 3.5
-DEFAULT_DEPTH_USE_LOG: bool = True
-
-
-def _validate_log_quant_params(depth_min: float, shift: float) -> None:
-    """Ensure ``log(depth_min + shift)`` is finite."""
-    if depth_min + shift <= 0:
-        raise ValueError(
-            f"depth_min + shift must be positive for logarithmic quantization, "
-            f"got depth_min={depth_min} + shift={shift} = {depth_min + shift}"
-        )
-
-
-def _depth_input_to_float32_and_unit(
-    depth: NDArray[np.uint16] | NDArray[np.floating] | torch.Tensor,
-    input_unit: Literal["auto", "m", "mm"],
-) -> tuple[NDArray[np.float32], Literal["m", "mm"]]:
-    """Depth as float32 in the chosen unit, plus the resolved unit."""
-    if isinstance(depth, torch.Tensor):
-        t = depth.detach().cpu()
-        arr = t.numpy()
-        is_floating = t.is_floating_point()
-    else:
-        arr = np.asarray(depth)
-        is_floating = np.issubdtype(arr.dtype, np.floating)
-
-    resolved_unit: Literal["m", "mm"]
-    if input_unit == "auto":
-        resolved_unit = "m" if is_floating else "mm"
-    else:
-        resolved_unit = input_unit
-
-    # Convert to float32 to keep typing consistency
-    return np.asarray(arr, dtype=np.float32, order="K"), resolved_unit
-
-
-def quantize_depth(
-    depth: NDArray[np.uint16] | NDArray[np.floating] | torch.Tensor,
-    depth_min: float = DEFAULT_DEPTH_MIN,
-    depth_max: float = DEFAULT_DEPTH_MAX,
-    shift: float = DEFAULT_DEPTH_SHIFT,
-    use_log: bool = DEFAULT_DEPTH_USE_LOG,
-    *,
-    input_unit: Literal["auto", "m", "mm"] = "auto",
-) -> NDArray[np.uint16]:
-    """Quantize depth to 12-bit codes (``uint16``, values ``0…DEPTH_QMAX``).
-
-    Depth maps are packed into 12-bit integer frames so they fit in standard
-    high-bit-depth pixel formats (e.g. ``yuv420p12le`` / ``gray12le``)
-    and can be encoded by widely supported video codecs (HEVC Main 12, ffv1).
-    Logarithmic quantization is the default because it allocates more quanta
-    to near-range depth, which matches the (1/depth) error profile of typical
-    depth sensors. Math is ported from BEHAVIOR-1K's ``obs_utils.py``.
-
-    **Input units**:
-
-    - ``input_unit="auto"`` (default): infer from dtype (floating = m, non-floating = mm).
-    - ``input_unit="mm"``: interpret input values as millimetres.
-    - ``input_unit="m"``: interpret input values as metres.
-
-    Quantization math runs in the **resolved input unit**. 
-    
-    ``depth_min``, ``depth_max``, and ``shift`` are always in **metres**.
-
-    Args:
-        depth: Depth map; ``torch.Tensor`` is moved to CPU for conversion.
-        depth_min: Depth (metres) at quantum ``0``.
-        depth_max: Depth (metres) at quantum :data:`DEPTH_QMAX`.
-        shift: Depth shift (metres); used in log mode. Must satisfy ``depth_min + shift > 0``.
-        use_log: If ``True`` (default), quantize in log space.
-        input_unit: Input unit policy (``"auto"``, ``"mm"``, ``"m"``).
-
-    Returns:
-        ``numpy.ndarray``, ``dtype=uint16``, same shape as ``depth``, values in
-        ``[0, DEPTH_QMAX]``.
-
-    Raises:
-        ValueError: If ``input_unit`` is not ``"auto"``, ``"mm"``, or ``"m"``.
-        ValueError: If ``use_log=True`` and ``depth_min + shift <= 0``.
-    """
-    if input_unit not in ("auto", "m", "mm"):
-        raise ValueError(f"input_unit must be 'auto', 'm', or 'mm', got {input_unit!r}")
-
-    depth_f, resolved_unit = _depth_input_to_float32_and_unit(depth, input_unit=input_unit)
-    depth_min_u = np.float32(depth_min) if resolved_unit == "m" else np.float32(depth_min * _MM_PER_METRE)
-    depth_max_u = np.float32(depth_max) if resolved_unit == "m" else np.float32(depth_max * _MM_PER_METRE)
-    shift_u = np.float32(shift) if resolved_unit == "m" else np.float32(shift * _MM_PER_METRE)
-
-    if use_log:
-        _validate_log_quant_params(depth_min, shift)
-        log_min = math.log(float(depth_min_u + shift_u))
-        log_max = math.log(float(depth_max_u + shift_u))
-        norm = (np.log(depth_f + shift_u) - log_min) / (log_max - log_min)
-    else:
-        norm = (depth_f - depth_min_u) / (depth_max_u - depth_min_u)
-
-    out = np.rint(norm * DEPTH_QMAX).clip(0, DEPTH_QMAX)
-    return out.astype(np.uint16, copy=False)
-
-
-def dequantize_depth(
-    quantized: NDArray[np.uint16] | torch.Tensor,
-    depth_min: float = DEFAULT_DEPTH_MIN,
-    depth_max: float = DEFAULT_DEPTH_MAX,
-    shift: float = DEFAULT_DEPTH_SHIFT,
-    use_log: bool = DEFAULT_DEPTH_USE_LOG,
-    *,
-    output_unit: Literal["m", "mm"] = "mm",
-) -> NDArray[np.uint16] | NDArray[np.float32]:
-    """Inverse of :func:`quantize_depth`.
-
-    Tuning arguments **must match** :func:`quantize_depth`.
-
-    Decoding inverts the same normalized code mapping as :func:`quantize_depth`
-    using ``depth_min`` / ``depth_max`` / ``shift`` (in metres), then returns
-    the requested output unit.
-
-    Args:
-        quantized: 12-bit codes ``[0, DEPTH_QMAX]``, ``dtype=uint16``.
-        depth_min, depth_max, shift, use_log: Same as :func:`quantize_depth` (metres).
-        output_unit: ``\"mm\"`` returns ``uint16`` millimetres (``rint``, clip
-            ``[0, 65535]``). ``\"m\"`` returns ``float32`` metres in
-            ``[depth_min, depth_max]``.
-
-    Returns:
-        Depth map in the requested unit and dtype.
-
-    Raises:
-        ValueError: If ``use_log=True`` and ``depth_min + shift <= 0``.
-        ValueError: If ``output_unit`` is not ``\"m\"`` or ``\"mm\"``.
-    """
-    if output_unit not in ("m", "mm"):
-        raise ValueError(f"output_unit must be 'm' or 'mm', got {output_unit!r}")
-
-    if isinstance(quantized, torch.Tensor):
-        quantized = quantized.detach().cpu().numpy()
-    q = np.asarray(quantized, dtype=np.uint16, order="K")
-    norm = q.astype(np.float32, copy=False) / DEPTH_QMAX
-
-    depth_min_mm = np.float32(depth_min * _MM_PER_METRE)
-    depth_max_mm = np.float32(depth_max * _MM_PER_METRE)
-    shift_mm = np.float32(shift * _MM_PER_METRE)
-
-    if use_log:
-        _validate_log_quant_params(depth_min, shift)
-        log_min = math.log(float(depth_min_mm + shift_mm))
-        log_max = math.log(float(depth_max_mm + shift_mm))
-        depth_mm = np.exp(norm * (log_max - log_min) + log_min) - shift_mm
-    else:
-        depth_mm = norm * (depth_max_mm - depth_min_mm) + depth_min_mm
-
-    depth_mm = np.clip(depth_mm, depth_min_mm, depth_max_mm).astype(np.float32, copy=False)
-    if output_unit == "m":
-        return (depth_mm / np.float32(_MM_PER_METRE)).astype(np.float32, copy=False)
-    mm = np.rint(depth_mm).clip(0, _UINT16_MAX)
-    return mm.astype(np.uint16, copy=False)

src/lerobot/datasets/factory.py

@@ -19,7 +19,6 @@ from pprint import pformat
 import torch
 
 from lerobot.configs import PreTrainedConfig
-from lerobot.configs.rewards import RewardModelConfig
 from lerobot.configs.train import TrainPipelineConfig
 from lerobot.transforms import ImageTransforms
 from lerobot.utils.constants import ACTION, IMAGENET_STATS, OBS_PREFIX, REWARD
@@ -31,14 +30,12 @@ from .streaming_dataset import StreamingLeRobotDataset
 
 
 def resolve_delta_timestamps(
-    cfg: PreTrainedConfig | RewardModelConfig, ds_meta: LeRobotDatasetMetadata
+    cfg: PreTrainedConfig, ds_meta: LeRobotDatasetMetadata
 ) -> dict[str, list] | None:
-    """Resolves delta_timestamps by reading from the 'delta_indices' properties of the config.
+    """Resolves delta_timestamps by reading from the 'delta_indices' properties of the PreTrainedConfig.
 
     Args:
-        cfg (PreTrainedConfig | RewardModelConfig): The config to read delta_indices from. Both
-            ``PreTrainedConfig`` and concrete ``RewardModelConfig`` subclasses expose the
-            ``{observation,action,reward}_delta_indices`` properties used below.
+        cfg (PreTrainedConfig): The PreTrainedConfig to read delta_indices from.
         ds_meta (LeRobotDatasetMetadata): The dataset from which features and fps are used to build
             delta_timestamps against.
 
@@ -85,7 +82,7 @@ def make_dataset(cfg: TrainPipelineConfig) -> LeRobotDataset | MultiLeRobotDatas
         ds_meta = LeRobotDatasetMetadata(
             cfg.dataset.repo_id, root=cfg.dataset.root, revision=cfg.dataset.revision
         )
-        delta_timestamps = resolve_delta_timestamps(cfg.trainable_config, ds_meta)
+        delta_timestamps = resolve_delta_timestamps(cfg.policy, ds_meta)
         if not cfg.dataset.streaming:
             dataset = LeRobotDataset(
                 cfg.dataset.repo_id,

src/lerobot/datasets/feature_utils.py

@@ -22,13 +22,18 @@ from PIL import Image as PILImage
 from lerobot.utils.constants import DEFAULT_FEATURES
 from lerobot.utils.utils import is_valid_numpy_dtype_string
 
+from .language import (
+    LANGUAGE_PERSISTENT,
+    is_language_column,
+    language_events_column_feature,
+    language_persistent_column_feature,
+)
 from .utils import (
     DEFAULT_CHUNK_SIZE,
     DEFAULT_DATA_FILE_SIZE_IN_MB,
     DEFAULT_DATA_PATH,
     DEFAULT_VIDEO_FILE_SIZE_IN_MB,
     DEFAULT_VIDEO_PATH,
-    DatasetInfo,
 )
 
 
@@ -46,7 +51,13 @@ def get_hf_features_from_features(features: dict) -> datasets.Features:
     """
     hf_features = {}
     for key, ft in features.items():
-        if ft["dtype"] == "video":
+        if is_language_column(key):
+            hf_features[key] = (
+                language_persistent_column_feature()
+                if key == LANGUAGE_PERSISTENT
+                else language_events_column_feature()
+            )
+        elif ft["dtype"] == "video":
             continue
         elif ft["dtype"] == "image":
             hf_features[key] = datasets.Image()
@@ -79,8 +90,8 @@ def create_empty_dataset_info(
     chunks_size: int | None = None,
     data_files_size_in_mb: int | None = None,
     video_files_size_in_mb: int | None = None,
-) -> DatasetInfo:
-    """Create a template ``DatasetInfo`` object for a new dataset's ``meta/info.json``.
+) -> dict:
+    """Create a template dictionary for a new dataset's `info.json`.
 
     Args:
         codebase_version (str): The version of the LeRobot codebase.
@@ -88,24 +99,25 @@ def create_empty_dataset_info(
         features (dict): The LeRobot features dictionary for the dataset.
         use_videos (bool): Whether the dataset will store videos.
         robot_type (str | None): The type of robot used, if any.
-        chunks_size (int | None): Max files per chunk directory. Defaults to ``DEFAULT_CHUNK_SIZE``.
-        data_files_size_in_mb (int | None): Max parquet file size in MB. Defaults to ``DEFAULT_DATA_FILE_SIZE_IN_MB``.
-        video_files_size_in_mb (int | None): Max video file size in MB. Defaults to ``DEFAULT_VIDEO_FILE_SIZE_IN_MB``.
 
     Returns:
-        DatasetInfo: A typed dataset information object with initial metadata.
+        dict: A dictionary with the initial dataset metadata.
     """
-    return DatasetInfo(
-        codebase_version=codebase_version,
-        fps=fps,
-        features=features,
-        robot_type=robot_type,
-        chunks_size=chunks_size or DEFAULT_CHUNK_SIZE,
-        data_files_size_in_mb=data_files_size_in_mb or DEFAULT_DATA_FILE_SIZE_IN_MB,
-        video_files_size_in_mb=video_files_size_in_mb or DEFAULT_VIDEO_FILE_SIZE_IN_MB,
-        data_path=DEFAULT_DATA_PATH,
-        video_path=DEFAULT_VIDEO_PATH if use_videos else None,
-    )
+    return {
+        "codebase_version": codebase_version,
+        "robot_type": robot_type,
+        "total_episodes": 0,
+        "total_frames": 0,
+        "total_tasks": 0,
+        "chunks_size": chunks_size or DEFAULT_CHUNK_SIZE,
+        "data_files_size_in_mb": data_files_size_in_mb or DEFAULT_DATA_FILE_SIZE_IN_MB,
+        "video_files_size_in_mb": video_files_size_in_mb or DEFAULT_VIDEO_FILE_SIZE_IN_MB,
+        "fps": fps,
+        "splits": {},
+        "data_path": DEFAULT_DATA_PATH,
+        "video_path": DEFAULT_VIDEO_PATH if use_videos else None,
+        "features": features,
+    }
 
 
 def check_delta_timestamps(
@@ -242,6 +254,8 @@ def validate_feature_dtype_and_shape(
         return validate_feature_image_or_video(name, expected_shape, value)
     elif expected_dtype == "string":
         return validate_feature_string(name, value)
+    elif expected_dtype == "language":
+        return ""
     else:
         raise NotImplementedError(f"The feature dtype '{expected_dtype}' is not implemented yet.")
 
@@ -294,20 +308,10 @@ def validate_feature_image_or_video(
     # Note: The check of pixels range ([0,1] for float and [0,255] for uint8) is done by the image writer threads.
     error_message = ""
     if isinstance(value, np.ndarray):
-        actual_shape = tuple(value.shape)
-        expected = tuple(expected_shape)
-        if len(expected) == 2:
-            # Single-channel features (e.g. depth maps) — accept (H,W), (1,H,W), (H,W,1)
-            h, w = expected
-            valid = actual_shape in {(h, w), (1, h, w), (h, w, 1)}
-            if not valid:
-                error_message += f"The feature '{name}' of shape '{actual_shape}' does not have the expected shape '{(h, w)}', '{(1, h, w)}', or '{(h, w, 1)}'.\n"
-        elif len(expected) == 3:
-            c, h, w = expected
-            if len(actual_shape) != 3 or (actual_shape != (c, h, w) and actual_shape != (h, w, c)):
-                error_message += f"The feature '{name}' of shape '{actual_shape}' does not have the expected shape '{(c, h, w)}' or '{(h, w, c)}'.\n"
-        else:
-            error_message += f"The feature '{name}' has an unsupported expected_shape '{expected}'.\n"
+        actual_shape = value.shape
+        c, h, w = expected_shape
+        if len(actual_shape) != 3 or (actual_shape != (c, h, w) and actual_shape != (h, w, c)):
+            error_message += f"The feature '{name}' of shape '{actual_shape}' does not have the expected shape '{(c, h, w)}' or '{(h, w, c)}'.\n"
     elif isinstance(value, PILImage.Image):
         pass
     else:

src/lerobot/datasets/image_writer.py

@@ -41,56 +41,15 @@ def safe_stop_image_writer(func):
     return wrapper
 
 
-# Single-channel dtypes that PIL natively maps to the matching mode
-# (``uint8`` → ``L``, ``uint16`` → ``I;16``, ``float32`` → ``F``).
-GRAYSCALE_DTYPES: tuple[np.dtype, ...] = (
-    np.dtype("uint8"),
-    np.dtype("uint16"),
-    np.dtype("float32"),
-)
-
-
 def image_array_to_pil_image(image_array: np.ndarray, range_check: bool = True) -> PIL.Image.Image:
-    """Convert a NumPy array to a PIL Image, preserving precision for grayscale.
+    # TODO(aliberts): handle 1 channel and 4 for depth images
+    if image_array.ndim != 3:
+        raise ValueError(f"The array has {image_array.ndim} dimensions, but 3 is expected for an image.")
 
-    Behaviour by shape:
-
-    - ``(H, W)`` or ``(1, H, W)`` / ``(H, W, 1)``: single-channel grayscale.
-      The native dtype is preserved using the matching PIL mode
-      (``L`` / ``I;16`` / ``F``). This is the path used for raw depth maps (no rescaling, clamping, or downcasting)
-    - ``(3, H, W)`` / ``(H, W, 3)``: RGB. Channels-first inputs are transposed
-      to channels-last. Float inputs in ``[0, 1]`` are scaled to ``uint8``
-      (existing behaviour, gated by ``range_check``).
-
-    Other shapes / channel counts raise ``NotImplementedError`` or
-    ``ValueError``.
-    """
-    if image_array.ndim not in (2, 3):
-        raise ValueError(
-            f"The array has {image_array.ndim} dimensions, but 2 or 3 is expected for an image."
-        )
-
-    # Squeeze 3D single-channel inputs to 2D so depth maps work whether the
-    # caller emits (H, W), (1, H, W), or (H, W, 1).
-    if image_array.ndim == 3:
-        if image_array.shape[0] == 1:
-            image_array = image_array[0]
-        elif image_array.shape[-1] == 1:
-            image_array = image_array[..., 0]
-
-    if image_array.ndim == 2:
-        if image_array.dtype not in GRAYSCALE_DTYPES:
-            raise ValueError(
-                f"Unsupported single-channel image dtype: {image_array.dtype}. "
-                f"Supported dtypes: {sorted(str(d) for d in GRAYSCALE_DTYPES)}."
-            )
-
-        return PIL.Image.fromarray(np.ascontiguousarray(image_array))
-
-    # 3D path: must be RGB (3 channels), channels-first or channels-last.
     if image_array.shape[0] == 3:
         # Transpose from pytorch convention (C, H, W) to (H, W, C)
         image_array = image_array.transpose(1, 2, 0)
+
     elif image_array.shape[-1] != 3:
         raise NotImplementedError(
             f"The image has {image_array.shape[-1]} channels, but 3 is required for now."
@@ -112,28 +71,13 @@ def image_array_to_pil_image(image_array: np.ndarray, range_check: bool = True)
     return PIL.Image.fromarray(image_array)
 
 
-def save_kwargs_for_path(fpath: Path, compress_level: int) -> dict:
-    """Pick the right format-specific kwargs for :meth:`PIL.Image.Image.save`.
-
-    PNG uses ``compress_level`` (0–9, zlib). TIFF uses ``compression`` (raw) for lossless raw depth maps.
-    """
-    suffix = Path(fpath).suffix.lower()
-    if suffix == ".png":
-        return {"compress_level": compress_level}
-    if suffix in (".tif", ".tiff"):
-        return {"compression": "raw"}
-    return {}
-
-
 def write_image(image: np.ndarray | PIL.Image.Image, fpath: Path, compress_level: int = 1):
     """
     Saves a NumPy array or PIL Image to a file.
 
     This function handles both NumPy arrays and PIL Image objects, converting
     the former to a PIL Image before saving. It includes error handling for
-    the save operation. The output format is inferred from the *fpath*
-    extension: ``.png`` → PNG with ``compress_level``, ``.tiff`` / ``.tif``
-    → lossless raw depth maps (TIFF).
+    the save operation.
 
     Args:
         image (np.ndarray | PIL.Image.Image): The image data to save.
@@ -157,7 +101,7 @@ def write_image(image: np.ndarray | PIL.Image.Image, fpath: Path, compress_level
             img = image
         else:
             raise TypeError(f"Unsupported image type: {type(image)}")
-        img.save(fpath, **save_kwargs_for_path(Path(fpath), compress_level))
+        img.save(fpath, compress_level=compress_level)
     except Exception as e:
         logger.error("Error writing image %s: %s", fpath, e)
 

src/lerobot/datasets/io_utils.py

@@ -34,12 +34,10 @@ from lerobot.utils.utils import SuppressProgressBars, flatten_dict, unflatten_di
 from .utils import (
     DEFAULT_DATA_FILE_SIZE_IN_MB,
     DEFAULT_EPISODES_PATH,
-    DEFAULT_SUBTASKS_PATH,
     DEFAULT_TASKS_PATH,
     EPISODES_DIR,
     INFO_PATH,
     STATS_PATH,
-    DatasetInfo,
     serialize_dict,
 )
 
@@ -116,21 +114,25 @@ def embed_images(dataset: datasets.Dataset) -> datasets.Dataset:
     return dataset
 
 
-def write_info(info: DatasetInfo, local_dir: Path) -> None:
-    write_json(info.to_dict(), local_dir / INFO_PATH)
+def write_info(info: dict, local_dir: Path) -> None:
+    write_json(info, local_dir / INFO_PATH)
 
 
-def load_info(local_dir: Path) -> DatasetInfo:
+def load_info(local_dir: Path) -> dict:
     """Load dataset info metadata from its standard file path.
 
+    Also converts shape lists to tuples for consistency.
+
     Args:
         local_dir (Path): The root directory of the dataset.
 
     Returns:
-        DatasetInfo: The typed dataset information object.
+        dict: The dataset information dictionary.
     """
-    raw = load_json(local_dir / INFO_PATH)
-    return DatasetInfo.from_dict(raw)
+    info = load_json(local_dir / INFO_PATH)
+    for ft in info["features"].values():
+        ft["shape"] = tuple(ft["shape"])
+    return info
 
 
 def write_stats(stats: dict, local_dir: Path) -> None:
@@ -186,14 +188,6 @@ def load_tasks(local_dir: Path) -> pandas.DataFrame:
     return tasks
 
 
-def load_subtasks(local_dir: Path) -> pandas.DataFrame | None:
-    """Load subtasks from subtasks.parquet if it exists."""
-    subtasks_path = local_dir / DEFAULT_SUBTASKS_PATH
-    if subtasks_path.exists():
-        return pd.read_parquet(subtasks_path)
-    return None
-
-
 def write_episodes(episodes: Dataset, local_dir: Path) -> None:
     """Write episode metadata to a parquet file in the LeRobot v3.0 format.
     This function writes episode-level metadata to a single parquet file.
@@ -265,11 +259,13 @@ def hf_transform_to_torch(items_dict: dict[str, list[Any]]) -> dict[str, list[to
         dict: The batch with items converted to torch tensors.
     """
     for key in items_dict:
+        if key in {"language_persistent", "language_events"}:
+            continue
         first_item = items_dict[key][0]
         if isinstance(first_item, PILImage.Image):
             to_tensor = transforms.ToTensor()
             items_dict[key] = [to_tensor(img) for img in items_dict[key]]
-        elif first_item is None:
+        elif first_item is None or isinstance(first_item, dict):
             pass
         else:
             items_dict[key] = [x if isinstance(x, str) else torch.tensor(x) for x in items_dict[key]]
@@ -305,7 +301,11 @@ def item_to_torch(item: dict) -> dict:
         dict: Dictionary with all tensor-like items converted to torch.Tensor.
     """
     for key, val in item.items():
-        if isinstance(val, (np.ndarray | list)) and key not in ["task"]:
+        if isinstance(val, (np.ndarray | list)) and key not in [
+            "task",
+            "language_persistent",
+            "language_events",
+        ]:
             # Convert numpy arrays and lists to torch tensors
             item[key] = torch.tensor(val)
     return item

src/lerobot/datasets/language.py

@@ -0,0 +1,150 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import annotations
+
+from typing import Literal
+
+import datasets
+import pyarrow as pa
+
+LANGUAGE_PERSISTENT = "language_persistent"
+LANGUAGE_EVENTS = "language_events"
+LANGUAGE_COLUMNS = (LANGUAGE_PERSISTENT, LANGUAGE_EVENTS)
+PERSISTENT_ROW_FIELDS = ("role", "content", "style", "timestamp", "tool_calls")
+EVENT_ROW_FIELDS = ("role", "content", "style", "tool_calls")
+
+CORE_STYLES = {"subtask", "plan", "memory", "motion", "interjection", "vqa", "trace"}
+EXTENDED_STYLES = set()
+STYLE_REGISTRY = CORE_STYLES | EXTENDED_STYLES
+
+PERSISTENT_STYLES = {"subtask", "plan", "memory", "motion"}
+EVENT_ONLY_STYLES = {"interjection", "vqa", "trace"}
+
+LanguageColumn = Literal["language_persistent", "language_events"]
+
+
+def _json_arrow_type() -> pa.DataType:
+    """Return the Arrow JSON type, falling back to ``string`` on older pyarrow."""
+    return pa.json_() if hasattr(pa, "json_") else pa.string()
+
+
+def _json_feature() -> object:
+    """Return the HF ``datasets`` JSON feature, falling back to a string value."""
+    return datasets.Json() if hasattr(datasets, "Json") else datasets.Value("string")
+
+
+def language_persistent_row_arrow_type() -> pa.StructType:
+    """Return the Arrow struct type for a single persistent language row.
+
+    Persistent rows carry their own ``timestamp`` because they represent a state
+    that became active at a specific moment and remains active until superseded.
+    """
+    return pa.struct(
+        [
+            pa.field("role", pa.string(), nullable=False),
+            pa.field("content", pa.string(), nullable=True),
+            pa.field("style", pa.string(), nullable=True),
+            pa.field("timestamp", pa.float64(), nullable=False),
+            pa.field("tool_calls", pa.list_(_json_arrow_type()), nullable=True),
+        ]
+    )
+
+
+def language_event_row_arrow_type() -> pa.StructType:
+    """Return the Arrow struct type for a single event language row.
+
+    Event rows have no ``timestamp`` field: each event is stored on the dataset
+    row whose frame timestamp is the event's firing time.
+    """
+    return pa.struct(
+        [
+            pa.field("role", pa.string(), nullable=False),
+            pa.field("content", pa.string(), nullable=True),
+            pa.field("style", pa.string(), nullable=True),
+            pa.field("tool_calls", pa.list_(_json_arrow_type()), nullable=True),
+        ]
+    )
+
+
+def language_persistent_arrow_type() -> pa.ListType:
+    """Return the Arrow list type for the ``language_persistent`` column."""
+    return pa.list_(language_persistent_row_arrow_type())
+
+
+def language_events_arrow_type() -> pa.ListType:
+    """Return the Arrow list type for the ``language_events`` column."""
+    return pa.list_(language_event_row_arrow_type())
+
+
+def language_persistent_row_feature() -> dict[str, object]:
+    """Return the HF ``datasets`` feature mapping for a persistent language row."""
+    return {
+        "role": datasets.Value("string"),
+        "content": datasets.Value("string"),
+        "style": datasets.Value("string"),
+        "timestamp": datasets.Value("float64"),
+        "tool_calls": datasets.List(_json_feature()),
+    }
+
+
+def language_event_row_feature() -> dict[str, object]:
+    """Return the HF ``datasets`` feature mapping for an event language row."""
+    return {
+        "role": datasets.Value("string"),
+        "content": datasets.Value("string"),
+        "style": datasets.Value("string"),
+        "tool_calls": datasets.List(_json_feature()),
+    }
+
+
+def language_persistent_column_feature() -> datasets.List:
+    """Return the HF ``datasets`` feature for the ``language_persistent`` column."""
+    return datasets.List(language_persistent_row_feature())
+
+
+def language_events_column_feature() -> datasets.List:
+    """Return the HF ``datasets`` feature for the ``language_events`` column."""
+    return datasets.List(language_event_row_feature())
+
+
+def language_feature_info() -> dict[str, dict]:
+    """Return the ``info["features"]`` entries for both language columns."""
+    return {
+        LANGUAGE_PERSISTENT: {"dtype": "language", "shape": (1,), "names": None},
+        LANGUAGE_EVENTS: {"dtype": "language", "shape": (1,), "names": None},
+    }
+
+
+def is_language_column(key: str) -> bool:
+    """Return ``True`` if ``key`` is one of the dataset's language column names."""
+    return key in LANGUAGE_COLUMNS
+
+
+def column_for_style(style: str | None) -> LanguageColumn:
+    """Map a language style to the column where rows of that style are stored.
+
+    Styles in :data:`PERSISTENT_STYLES` route to :data:`LANGUAGE_PERSISTENT`.
+    Styles in :data:`EVENT_ONLY_STYLES` and the implicit ``None`` style route
+    to :data:`LANGUAGE_EVENTS`.
+    """
+    if style is None:
+        return LANGUAGE_EVENTS
+    if style in PERSISTENT_STYLES:
+        return LANGUAGE_PERSISTENT
+    if style in EVENT_ONLY_STYLES:
+        return LANGUAGE_EVENTS
+    raise ValueError(f"Unknown language style: {style!r}")

src/lerobot/datasets/language_render.py

@@ -0,0 +1,511 @@
+#!/usr/bin/env python
+
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import annotations
+
+import copy
+import hashlib
+import re
+from collections.abc import Sequence
+from typing import Any
+
+from lerobot.configs.recipe import DEFAULT_BINDINGS, TrainingRecipe
+
+from .language import (
+    EVENT_ONLY_STYLES,
+    LANGUAGE_PERSISTENT,
+    PERSISTENT_STYLES,
+    column_for_style,
+)
+
+LanguageRow = dict[str, Any]
+RenderedMessages = dict[str, list[Any]]
+
+_RESOLVER_RE = re.compile(r"^(?P<name>[A-Za-z_][A-Za-z0-9_]*)\((?P<args>.*)\)$")
+_PLACEHOLDER_RE = re.compile(r"\$\{([A-Za-z_][A-Za-z0-9_]*)\}")
+
+
+def active_at(
+    t: float,
+    *,
+    persistent: Sequence[LanguageRow],
+    events: Sequence[LanguageRow] | None = None,
+    style: str | None = None,
+    role: str | None = None,
+    tool_name: str | None = None,
+) -> LanguageRow | None:
+    """Return the persistent row of ``style`` that is active at time ``t``.
+
+    A persistent row is "active" at ``t`` when its own ``timestamp`` is the
+    most recent one ``<= t`` for the given ``style``/``role``/``tool_name``
+    selector. ``events`` is accepted for resolver-signature uniformity but is
+    not consulted: only persistent styles are valid here.
+    """
+    _validate_persistent_resolver("active_at", style)
+    matches = _matching_rows(persistent, style=style, role=role, tool_name=tool_name)
+    matches = [row for row in matches if _timestamp(row) <= t]
+    return _select_latest(matches, style=style, role=role, tool_name=tool_name)
+
+
+def emitted_at(
+    t: float,
+    *,
+    persistent: Sequence[LanguageRow],
+    events: Sequence[LanguageRow],
+    style: str | None = None,
+    role: str | None = None,
+    tool_name: str | None = None,
+) -> LanguageRow | None:
+    """Return the row of ``style`` emitted at exactly time ``t``.
+
+    For persistent styles, this matches persistent rows whose own ``timestamp``
+    equals ``t``. For event styles, the ``events`` list is assumed to come from
+    the dataset row at frame ``t`` (event rows carry no timestamp of their own),
+    so all matching event rows are considered emitted at ``t``.
+    """
+    column = column_for_style(style)
+    if column == LANGUAGE_PERSISTENT:
+        matches = [
+            row
+            for row in _matching_rows(persistent, style=style, role=role, tool_name=tool_name)
+            if _timestamp(row) == t
+        ]
+        return _select_one(
+            matches, style=style, role=role, tool_name=tool_name, sort_key=_persistent_sort_key
+        )
+    matches = _matching_rows(events, style=style, role=role, tool_name=tool_name)
+    return _select_one(matches, style=style, role=role, tool_name=tool_name, sort_key=_event_sort_key)
+
+
+def nth_prev(
+    t: float,
+    *,
+    persistent: Sequence[LanguageRow],
+    events: Sequence[LanguageRow] | None = None,
+    style: str | None = None,
+    offset: int = 1,
+    role: str | None = None,
+    tool_name: str | None = None,
+) -> LanguageRow | None:
+    """Return the persistent row that was active ``offset`` steps before ``t``.
+
+    Walks back through chronologically sorted persistent rows of ``style``
+    (filtered by optional ``role``/``tool_name``) and returns the one ``offset``
+    positions before the row active at ``t``. Only valid for persistent styles.
+    """
+    return _nth_relative(
+        t,
+        persistent=persistent,
+        style=style,
+        offset=-offset,
+        role=role,
+        tool_name=tool_name,
+        resolver_name="nth_prev",
+    )
+
+
+def nth_next(
+    t: float,
+    *,
+    persistent: Sequence[LanguageRow],
+    events: Sequence[LanguageRow] | None = None,
+    style: str | None = None,
+    offset: int = 1,
+    role: str | None = None,
+    tool_name: str | None = None,
+) -> LanguageRow | None:
+    """Return the persistent row that becomes active ``offset`` steps after ``t``.
+
+    Walks forward through chronologically sorted persistent rows of ``style``
+    (filtered by optional ``role``/``tool_name``) and returns the one ``offset``
+    positions after the row active at ``t``. Only valid for persistent styles.
+    """
+    return _nth_relative(
+        t,
+        persistent=persistent,
+        style=style,
+        offset=offset,
+        role=role,
+        tool_name=tool_name,
+        resolver_name="nth_next",
+    )
+
+
+def render_sample(
+    *,
+    recipe: TrainingRecipe,
+    persistent: Sequence[LanguageRow] | None,
+    events: Sequence[LanguageRow] | None,
+    t: float,
+    sample_idx: int,
+    task: str | None = None,
+    dataset_ctx: Any | None = None,
+) -> RenderedMessages | None:
+    """Render the chat-style messages for a single dataset sample.
+
+    Resolves the recipe's bindings against ``persistent`` and ``events`` rows
+    at frame timestamp ``t``, then expands the recipe's message templates.
+    Returns ``None`` if the resolved sample contains no target message.
+    """
+    persistent_rows = _normalize_rows(persistent or [])
+    event_rows = _normalize_rows(events or [])
+    selected_recipe = _select_recipe(recipe, sample_idx)
+    bindings = _resolve_bindings(
+        selected_recipe,
+        persistent=persistent_rows,
+        events=event_rows,
+        t=t,
+        task=task,
+        dataset_ctx=dataset_ctx,
+    )
+    return _render_message_recipe(selected_recipe, bindings)
+
+
+def _select_recipe(recipe: TrainingRecipe, sample_idx: int) -> TrainingRecipe:
+    """Pick a deterministic blend component for ``sample_idx`` (or return ``recipe``)."""
+    if recipe.blend is None:
+        return recipe
+
+    total_weight = sum(component.weight or 0.0 for component in recipe.blend.values())
+    if total_weight <= 0:
+        raise ValueError("Blend weights must sum to a positive value.")
+
+    digest = hashlib.blake2b(str(sample_idx).encode(), digest_size=8).digest()
+    draw = int.from_bytes(digest, "big") / 2**64 * total_weight
+    cumulative = 0.0
+    last_component: TrainingRecipe | None = None
+    for component in recipe.blend.values():
+        last_component = component
+        cumulative += component.weight or 0.0
+        if draw < cumulative:
+            return component
+    assert last_component is not None
+    return last_component
+
+
+def _resolve_bindings(
+    recipe: TrainingRecipe,
+    *,
+    persistent: Sequence[LanguageRow],
+    events: Sequence[LanguageRow],
+    t: float,
+    task: str | None,
+    dataset_ctx: Any | None,
+) -> dict[str, LanguageRow | str | None]:
+    """Resolve every binding in ``recipe`` (plus ``task``) at time ``t``."""
+    bindings: dict[str, LanguageRow | str | None] = {"task": _resolve_task(task, dataset_ctx)}
+    specs = {**DEFAULT_BINDINGS, **(recipe.bindings or {})}
+    for name, spec in specs.items():
+        bindings[name] = _resolve_spec(spec, persistent=persistent, events=events, t=t)
+    return bindings
+
+
+def _resolve_task(task: str | None, dataset_ctx: Any | None) -> str | None:
+    """Return ``task`` if set, otherwise look it up on ``dataset_ctx``."""
+    if task is not None:
+        return task
+    if dataset_ctx is None:
+        return None
+    if isinstance(dataset_ctx, dict):
+        return dataset_ctx.get("task")
+    return getattr(dataset_ctx, "task", None)
+
+
+def _resolve_spec(
+    spec: str,
+    *,
+    persistent: Sequence[LanguageRow],
+    events: Sequence[LanguageRow],
+    t: float,
+) -> LanguageRow | None:
+    """Parse a single binding's resolver expression and dispatch to its function."""
+    match = _RESOLVER_RE.match(spec.strip())
+    if match is None:
+        raise ValueError(f"Invalid resolver expression: {spec!r}")
+    name = match.group("name")
+    kwargs = _parse_resolver_args(match.group("args"))
+    kwargs.pop("t_arg", None)
+
+    resolvers = {
+        "active_at": active_at,
+        "emitted_at": emitted_at,
+        "nth_prev": nth_prev,
+        "nth_next": nth_next,
+    }
+    if name not in resolvers:
+        raise ValueError(f"Unknown language resolver: {name!r}")
+    return resolvers[name](t, persistent=persistent, events=events, **kwargs)
+
+
+def _parse_resolver_args(args: str) -> dict[str, Any]:
+    """Parse a comma-separated resolver argument list into a kwargs dict."""
+    kwargs: dict[str, Any] = {}
+    if not args.strip():
+        return kwargs
+
+    parts = [part.strip() for part in args.split(",") if part.strip()]
+    for part in parts:
+        if part == "t":
+            kwargs["t_arg"] = True
+            continue
+        if "=" not in part:
+            raise ValueError(f"Invalid resolver argument: {part!r}")
+        key, value = (item.strip() for item in part.split("=", 1))
+        if key == "offset":
+            kwargs[key] = int(value)
+        else:
+            kwargs[key] = value.strip("\"'")
+    return kwargs
+
+
+def _render_message_recipe(
+    recipe: TrainingRecipe,
+    bindings: dict[str, LanguageRow | str | None],
+) -> RenderedMessages | None:
+    """Expand ``recipe.messages`` into rendered chat messages using ``bindings``."""
+    assert recipe.messages is not None
+    messages: list[dict[str, Any]] = []
+    streams: list[str | None] = []
+    target_indices: list[int] = []
+
+    for turn in recipe.messages:
+        if turn.if_present is not None and bindings.get(turn.if_present) is None:
+            continue
+
+        message = {"role": turn.role}
+        if turn.content is not None:
+            message["content"] = _render_content(turn.content, bindings)
+
+        if turn.tool_calls_from is not None:
+            row = bindings.get(turn.tool_calls_from)
+            tool_calls = row.get("tool_calls") if isinstance(row, dict) else None
+            if tool_calls:
+                message["tool_calls"] = copy.deepcopy(tool_calls)
+
+        message_idx = len(messages)
+        messages.append(message)
+        streams.append(turn.stream)
+        if turn.target:
+            target_indices.append(message_idx)
+
+    if not target_indices:
+        return None
+
+    rendered = {
+        "messages": messages,
+        "message_streams": streams,
+        "target_message_indices": target_indices,
+    }
+    _validate_rendered(rendered)
+    return rendered
+
+
+def _render_content(
+    content: str | list[dict[str, Any]],
+    bindings: dict[str, LanguageRow | str | None],
+) -> str | list[dict[str, Any]]:
+    """Substitute bindings into a string or each string field of multimodal blocks."""
+    if isinstance(content, str):
+        return _substitute(content, bindings)
+
+    rendered_blocks = []
+    for block in content:
+        rendered_block = copy.deepcopy(block)
+        for key, value in rendered_block.items():
+            if isinstance(value, str):
+                rendered_block[key] = _substitute(value, bindings)
+        rendered_blocks.append(rendered_block)
+    return rendered_blocks
+
+
+def _substitute(template: str, bindings: dict[str, LanguageRow | str | None]) -> str:
+    """Replace ``${name}`` placeholders in ``template`` with their bound values."""
+
+    def replace(match: re.Match[str]) -> str:
+        """Resolve a single ``${name}`` match to its bound string value."""
+        name = match.group(1)
+        if name not in bindings:
+            raise ValueError(f"Unknown template binding: {name!r}")
+        value = bindings[name]
+        if value is None:
+            return ""
+        if isinstance(value, dict):
+            content = value.get("content")
+            return "" if content is None else str(content)
+        return str(value)
+
+    return _PLACEHOLDER_RE.sub(replace, template)
+
+
+def _validate_rendered(rendered: RenderedMessages) -> None:
+    """Sanity-check the rendered output for stream/target alignment."""
+    messages = rendered["messages"]
+    streams = rendered["message_streams"]
+    target_indices = rendered["target_message_indices"]
+
+    if len(streams) != len(messages):
+        raise ValueError("message_streams must be aligned with messages.")
+    if not target_indices:
+        raise ValueError("Rendered samples must contain at least one target message.")
+    for idx in target_indices:
+        if idx < 0 or idx >= len(messages):
+            raise ValueError(f"Target message index {idx} is out of bounds.")
+    for idx, stream in enumerate(streams):
+        if stream is None:
+            raise ValueError(f"Rendered message {idx} has no stream.")
+
+
+def _nth_relative(
+    t: float,
+    *,
+    persistent: Sequence[LanguageRow],
+    style: str | None,
+    offset: int,
+    role: str | None,
+    tool_name: str | None,
+    resolver_name: str,
+) -> LanguageRow | None:
+    """Shared body for ``nth_prev`` / ``nth_next`` with signed ``offset``."""
+    _validate_persistent_resolver(resolver_name, style)
+    if abs(offset) < 1:
+        raise ValueError(f"{resolver_name} offset must be non-zero.")
+
+    rows = sorted(
+        _matching_rows(persistent, style=style, role=role, tool_name=tool_name),
+        key=_persistent_sort_key,
+    )
+    if not rows:
+        return None
+
+    anchor_idx = None
+    for idx, row in enumerate(rows):
+        if _timestamp(row) <= t:
+            anchor_idx = idx
+        else:
+            break
+
+    target_idx = (offset - 1 if offset > 0 else None) if anchor_idx is None else anchor_idx + offset
+
+    if target_idx is None or target_idx < 0 or target_idx >= len(rows):
+        return None
+    return rows[target_idx]
+
+
+def _validate_persistent_resolver(resolver_name: str, style: str | None) -> None:
+    """Reject calls with missing or event-only ``style`` for persistent resolvers."""
+    if style is None:
+        raise ValueError(f"{resolver_name} requires a persistent style.")
+    if style in EVENT_ONLY_STYLES:
+        raise ValueError(f"{resolver_name} cannot be used with event-only style {style!r}.")
+    if style not in PERSISTENT_STYLES:
+        column_for_style(style)
+
+
+def _matching_rows(
+    rows: Sequence[LanguageRow],
+    *,
+    style: str | None,
+    role: str | None,
+    tool_name: str | None,
+) -> list[LanguageRow]:
+    """Return ``rows`` filtered by optional ``style``/``role``/``tool_name`` selectors."""
+    return [
+        row
+        for row in rows
+        if (style is None or row.get("style") == style)
+        and (role is None or row.get("role") == role)
+        and (tool_name is None or _row_has_tool_name(row, tool_name))
+    ]
+
+
+def _select_latest(
+    rows: Sequence[LanguageRow],
+    *,
+    style: str | None,
+    role: str | None,
+    tool_name: str | None,
+) -> LanguageRow | None:
+    """Return the row tied for the latest ``timestamp`` (disambiguated by selectors)."""
+    if not rows:
+        return None
+    rows = sorted(rows, key=_persistent_sort_key)
+    latest_ts = _timestamp(rows[-1])
+    return _select_one(
+        [row for row in rows if _timestamp(row) == latest_ts],
+        style=style,
+        role=role,
+        tool_name=tool_name,
+        sort_key=_persistent_sort_key,
+    )
+
+
+def _select_one(
+    rows: Sequence[LanguageRow],
+    *,
+    style: str | None,
+    role: str | None,
+    tool_name: str | None,
+    sort_key: Any,
+) -> LanguageRow | None:
+    """Return the single matching row, or raise if the selectors are ambiguous."""
+    if not rows:
+        return None
+    if len(rows) > 1 and role is None and tool_name is None:
+        raise ValueError(
+            f"Ambiguous resolver for style={style!r}; add role=... or tool_name=... to disambiguate."
+        )
+    return sorted(rows, key=sort_key)[0]
+
+
+def _persistent_sort_key(row: LanguageRow) -> tuple[float, str, str]:
+    """Sort key for persistent rows: ``(timestamp, style, role)``."""
+    return (_timestamp(row), row.get("style") or "", row.get("role") or "")
+
+
+def _event_sort_key(row: LanguageRow) -> tuple[str, str]:
+    """Sort key for event rows: ``(style, role)`` (timestamp is implicit in the frame)."""
+    return (row.get("style") or "", row.get("role") or "")
+
+
+def _timestamp(row: LanguageRow) -> float:
+    """Extract a row's ``timestamp`` as a Python float (unwrapping numpy scalars)."""
+    value = row["timestamp"]
+    return float(value.item() if hasattr(value, "item") else value)
+
+
+def _row_has_tool_name(row: LanguageRow, tool_name: str) -> bool:
+    """Return ``True`` if any of the row's tool calls invokes ``tool_name``."""
+    for tool_call in row.get("tool_calls") or []:
+        if isinstance(tool_call, str):
+            continue
+        function = tool_call.get("function") if isinstance(tool_call, dict) else None
+        if isinstance(function, dict) and function.get("name") == tool_name:
+            return True
+    return False
+
+
+def _normalize_rows(rows: Sequence[Any]) -> list[LanguageRow]:
+    """Convert pyarrow scalars / mappings into a fresh list of plain dict rows."""
+    normalized = []
+    for row in rows:
+        if row is None:
+            continue
+        if hasattr(row, "as_py"):
+            row = row.as_py()
+        if not isinstance(row, dict):
+            raise TypeError(f"Language rows must be dictionaries, got {type(row).__name__}.")
+        normalized.append(dict(row))
+    return normalized

src/lerobot/datasets/lerobot_dataset.py

@@ -35,11 +35,9 @@ from .utils import (
     is_valid_version,
 )
 from .video_utils import (
-    DepthEncoderConfig,
     StreamingVideoEncoder,
-    VideoEncoderConfig,
-    get_safe_default_video_backend,
-    seed_depth_feature_info,
+    get_safe_default_codec,
+    resolve_vcodec,
 )
 
 logger = logging.getLogger(__name__)
@@ -60,11 +58,10 @@ class LeRobotDataset(torch.utils.data.Dataset):
         video_backend: str | None = None,
         return_uint8: bool = False,
         batch_encoding_size: int = 1,
-        camera_encoder_config: VideoEncoderConfig | None = None,
-        depth_encoder_config: DepthEncoderConfig | None = None,
-        encoder_threads: int | None = None,
+        vcodec: str = "libsvtav1",
         streaming_encoding: bool = False,
         encoder_queue_maxsize: int = 30,
+        encoder_threads: int | None = None,
     ):
         """
         2 modes are available for instantiating this class, depending on 2 different use cases:
@@ -180,15 +177,16 @@ class LeRobotDataset(torch.utils.data.Dataset):
                 You can also use the 'pyav' decoder used by Torchvision, which used to be the default option, or 'video_reader' which is another decoder of Torchvision.
             batch_encoding_size (int, optional): Number of episodes to accumulate before batch encoding videos.
                 Set to 1 for immediate encoding (default), or higher for batched encoding. Defaults to 1.
-            camera_encoder_config (VideoEncoderConfig | None, optional): Video encoder settings for cameras
-                (codec, quality, etc.). Defaults to
-                :class:`~lerobot.datasets.video_utils.VideoEncoderConfig` defaults when ``None``.
-            encoder_threads (int | None, optional): Number of encoder threads (global). ``None`` lets the
-                codec decide.
+            vcodec (str, optional): Video codec for encoding videos during recording. Options: 'h264', 'hevc',
+                'libsvtav1', 'auto', or hardware-specific codecs like 'h264_videotoolbox', 'h264_nvenc'.
+                Defaults to 'libsvtav1'. Use 'auto' to auto-detect the best available hardware encoder.
             streaming_encoding (bool, optional): If True, encode video frames in real-time during capture
                 instead of writing PNG images first. This makes save_episode() near-instant. Defaults to False.
             encoder_queue_maxsize (int, optional): Maximum number of frames to buffer per camera when using
                 streaming encoding. Defaults to 30 (~1s at 30fps).
+            encoder_threads (int | None, optional): Number of threads per encoder instance. None lets the
+                codec auto-detect (default). Lower values reduce CPU usage per encoder. Maps to 'lp' (via svtav1-params) for
+                libsvtav1 and 'threads' for h264/hevc.
 
         Note:
             Write-mode parameters (``streaming_encoding``, ``batch_encoding_size``) passed to
@@ -204,13 +202,10 @@ class LeRobotDataset(torch.utils.data.Dataset):
         self.episodes = episodes
         self.tolerance_s = tolerance_s
         self.revision = revision if revision else CODEBASE_VERSION
-        self._video_backend = video_backend if video_backend else get_safe_default_video_backend()
+        self._video_backend = video_backend if video_backend else get_safe_default_codec()
         self._return_uint8 = return_uint8
         self._batch_encoding_size = batch_encoding_size
-        if camera_encoder_config is None:
-            camera_encoder_config = VideoEncoderConfig()
-        self._camera_encoder_config = camera_encoder_config
-        self._depth_encoder_config = depth_encoder_config
+        self._vcodec = resolve_vcodec(vcodec)
         self._encoder_threads = encoder_threads
 
         if self._requested_root is not None:
@@ -253,23 +248,16 @@ class LeRobotDataset(torch.utils.data.Dataset):
                 DeprecationWarning,
                 stacklevel=2,
             )
-            seed_depth_feature_info(self.meta.features, self._depth_encoder_config)
             streaming_enc = None
             if streaming_encoding and len(self.meta.video_keys) > 0:
                 streaming_enc = self._build_streaming_encoder(
-                    self.meta.fps,
-                    self._camera_encoder_config,
-                    self._encoder_threads,
-                    encoder_queue_maxsize,
-                    depth_encoder_config=self._depth_encoder_config,
-                    depth_keys=self.meta.depth_keys,
+                    self.meta.fps, self._vcodec, encoder_queue_maxsize, encoder_threads
                 )
             self.writer = DatasetWriter(
                 meta=self.meta,
                 root=self.root,
-                camera_encoder_config=self._camera_encoder_config,
-                depth_encoder_config=self._depth_encoder_config,
-                encoder_threads=self._encoder_threads,
+                vcodec=self._vcodec,
+                encoder_threads=encoder_threads,
                 batch_encoding_size=batch_encoding_size,
                 streaming_encoder=streaming_enc,
                 initial_frames=self.meta.total_frames,
@@ -310,20 +298,19 @@ class LeRobotDataset(torch.utils.data.Dataset):
     @staticmethod
     def _build_streaming_encoder(
         fps: int,
-        camera_encoder_config: VideoEncoderConfig,
-        encoder_threads: int | None,
+        vcodec: str,
         encoder_queue_maxsize: int,
-        *,
-        depth_encoder_config: DepthEncoderConfig | None = None,
-        depth_keys: list[str] | None = None,
+        encoder_threads: int | None,
     ) -> StreamingVideoEncoder:
         return StreamingVideoEncoder(
             fps=fps,
-            camera_encoder_config=camera_encoder_config,
-            encoder_threads=encoder_threads,
+            vcodec=vcodec,
+            pix_fmt="yuv420p",
+            g=2,
+            crf=30,
+            preset=None,
             queue_maxsize=encoder_queue_maxsize,
-            depth_encoder_config=depth_encoder_config,
-            depth_keys=depth_keys,
+            encoder_threads=encoder_threads,
         )
 
     # ── Metadata properties ───────────────────────────────────────────
@@ -638,14 +625,11 @@ class LeRobotDataset(torch.utils.data.Dataset):
         image_writer_threads: int = 0,
         video_backend: str | None = None,
         batch_encoding_size: int = 1,
-        camera_encoder_config: VideoEncoderConfig | None = None,
-        depth_encoder_config: DepthEncoderConfig | None = None,
+        vcodec: str = "libsvtav1",
         metadata_buffer_size: int = 10,
         streaming_encoding: bool = False,
         encoder_queue_maxsize: int = 30,
         encoder_threads: int | None = None,
-        video_files_size_in_mb: int | None = None,
-        data_files_size_in_mb: int | None = None,
     ) -> "LeRobotDataset":
         """Create a new LeRobotDataset from scratch for recording data.
 
@@ -670,23 +654,20 @@ class LeRobotDataset(torch.utils.data.Dataset):
             video_backend: Video decoding backend (used when reading back).
             batch_encoding_size: Number of episodes to accumulate before
                 batch-encoding videos. ``1`` means encode immediately.
-            camera_encoder_config: Video encoder settings for cameras; defaults
-                match :class:`~lerobot.datasets.video_utils.VideoEncoderConfig`
-                when ``None``.
-            encoder_threads: Number of encoder threads (global). ``None``
-                lets the codec decide.
+            vcodec: Video codec for encoding. Options include ``'libsvtav1'``,
+                ``'h264'``, ``'hevc'``, ``'auto'``.
             metadata_buffer_size: Number of episode metadata records to buffer
                 before flushing to parquet.
             streaming_encoding: If ``True``, encode video frames in real-time
                 during capture instead of writing images first.
             encoder_queue_maxsize: Max buffered frames per camera when using
                 streaming encoding.
+            encoder_threads: Threads per encoder instance. ``None`` for auto.
 
         Returns:
             A new :class:`LeRobotDataset` in write mode.
         """
-        if camera_encoder_config is None:
-            camera_encoder_config = VideoEncoderConfig()
+        vcodec = resolve_vcodec(vcodec)
         obj = cls.__new__(cls)
         obj.meta = LeRobotDatasetMetadata.create(
             repo_id=repo_id,
@@ -696,8 +677,6 @@ class LeRobotDataset(torch.utils.data.Dataset):
             root=root,
             use_videos=use_videos,
             metadata_buffer_size=metadata_buffer_size,
-            video_files_size_in_mb=video_files_size_in_mb,
-            data_files_size_in_mb=data_files_size_in_mb,
         )
         obj.repo_id = obj.meta.repo_id
         obj._requested_root = obj.meta.root
@@ -707,32 +686,23 @@ class LeRobotDataset(torch.utils.data.Dataset):
         obj.image_transforms = None
         obj.delta_timestamps = None
         obj.episodes = None
-        obj._video_backend = video_backend if video_backend is not None else get_safe_default_video_backend()
+        obj._video_backend = video_backend if video_backend is not None else get_safe_default_codec()
         obj._return_uint8 = False
         obj._batch_encoding_size = batch_encoding_size
-        obj._camera_encoder_config = camera_encoder_config
-        obj._depth_encoder_config = depth_encoder_config
+        obj._vcodec = vcodec
         obj._encoder_threads = encoder_threads
-        seed_depth_feature_info(obj.meta.features, depth_encoder_config)
 
         # Reader is lazily created on first access (write-only mode)
         obj.reader = None
 
+        # Create writer
         streaming_enc = None
         if streaming_encoding and len(obj.meta.video_keys) > 0:
-            streaming_enc = cls._build_streaming_encoder(
-                fps,
-                camera_encoder_config,
-                encoder_threads,
-                encoder_queue_maxsize,
-                depth_encoder_config=depth_encoder_config,
-                depth_keys=obj.meta.depth_keys,
-            )
+            streaming_enc = cls._build_streaming_encoder(fps, vcodec, encoder_queue_maxsize, encoder_threads)
         obj.writer = DatasetWriter(
             meta=obj.meta,
             root=obj.root,
-            camera_encoder_config=camera_encoder_config,
-            depth_encoder_config=depth_encoder_config,
+            vcodec=vcodec,
             encoder_threads=encoder_threads,
             batch_encoding_size=batch_encoding_size,
             streaming_encoder=streaming_enc,
@@ -755,13 +725,12 @@ class LeRobotDataset(torch.utils.data.Dataset):
         force_cache_sync: bool = False,
         video_backend: str | None = None,
         batch_encoding_size: int = 1,
-        camera_encoder_config: VideoEncoderConfig | None = None,
-        depth_encoder_config: DepthEncoderConfig | None = None,
-        encoder_threads: int | None = None,
+        vcodec: str = "libsvtav1",
         image_writer_processes: int = 0,
         image_writer_threads: int = 0,
         streaming_encoding: bool = False,
         encoder_queue_maxsize: int = 30,
+        encoder_threads: int | None = None,
     ) -> "LeRobotDataset":
         """Resume recording on an existing dataset.
 
@@ -784,16 +753,13 @@ class LeRobotDataset(torch.utils.data.Dataset):
             video_backend: Video decoding backend for reading back data.
             batch_encoding_size: Number of episodes to accumulate before
                 batch-encoding videos.
-            camera_encoder_config: Video encoder settings for cameras; defaults
-                match :class:`~lerobot.datasets.video_utils.VideoEncoderConfig`
-                when ``None``.
-            encoder_threads: Number of encoder threads (global). ``None``
-                lets the codec decide.
+            vcodec: Video codec for encoding.
             image_writer_processes: Subprocesses for async image writing.
             image_writer_threads: Threads for async image writing.
             streaming_encoding: If ``True``, encode video in real-time during
                 capture.
             encoder_queue_maxsize: Max buffered frames per camera for streaming.
+            encoder_threads: Threads per encoder instance. ``None`` for auto.
 
         Returns:
             A :class:`LeRobotDataset` in write mode, ready to append episodes.
@@ -804,6 +770,7 @@ class LeRobotDataset(torch.utils.data.Dataset):
                 "Writing into the revision-safe Hub snapshot cache (used when root=None) would corrupt "
                 "the shared cache. Please provide a local directory path."
             )
+        vcodec = resolve_vcodec(vcodec)
         obj = cls.__new__(cls)
         obj.repo_id = repo_id
         obj._requested_root = Path(root)
@@ -812,9 +779,11 @@ class LeRobotDataset(torch.utils.data.Dataset):
         obj.image_transforms = None
         obj.delta_timestamps = None
         obj.episodes = None
-        obj._video_backend = video_backend if video_backend else get_safe_default_video_backend()
+        obj._video_backend = video_backend if video_backend else get_safe_default_codec()
         obj._return_uint8 = False
         obj._batch_encoding_size = batch_encoding_size
+        obj._vcodec = vcodec
+        obj._encoder_threads = encoder_threads
 
         if obj._requested_root is not None:
             obj._requested_root.mkdir(exist_ok=True, parents=True)
@@ -823,33 +792,21 @@ class LeRobotDataset(torch.utils.data.Dataset):
         obj.meta = LeRobotDatasetMetadata(
             obj.repo_id, obj._requested_root, obj.revision, force_cache_sync=force_cache_sync
         )
-
-        if camera_encoder_config is None:
-            camera_encoder_config = VideoEncoderConfig()
-        obj._camera_encoder_config = camera_encoder_config
-        obj._depth_encoder_config = depth_encoder_config
-        obj._encoder_threads = encoder_threads
         obj.root = obj.meta.root
-        seed_depth_feature_info(obj.meta.features, depth_encoder_config)
 
         # Reader is lazily created on first access (write-only mode)
         obj.reader = None
 
+        # Create writer for appending
         streaming_enc = None
         if streaming_encoding and len(obj.meta.video_keys) > 0:
             streaming_enc = cls._build_streaming_encoder(
-                obj.meta.fps,
-                camera_encoder_config,
-                encoder_threads,
-                encoder_queue_maxsize,
-                depth_encoder_config=depth_encoder_config,
-                depth_keys=obj.meta.depth_keys,
+                obj.meta.fps, vcodec, encoder_queue_maxsize, encoder_threads
             )
         obj.writer = DatasetWriter(
             meta=obj.meta,
             root=obj.root,
-            camera_encoder_config=camera_encoder_config,
-            depth_encoder_config=depth_encoder_config,
+            vcodec=vcodec,
             encoder_threads=encoder_threads,
             batch_encoding_size=batch_encoding_size,
             streaming_encoder=streaming_enc,

src/lerobot/datasets/multi_dataset.py

@@ -123,7 +123,7 @@ class MultiLeRobotDataset(torch.utils.data.Dataset):
 
         NOTE: Fow now, this relies on a check in __init__ to make sure all sub-datasets have the same info.
         """
-        return self._datasets[0].meta.info.fps
+        return self._datasets[0].meta.info["fps"]
 
     @property
     def video(self) -> bool:
@@ -133,7 +133,7 @@ class MultiLeRobotDataset(torch.utils.data.Dataset):
 
         NOTE: Fow now, this relies on a check in __init__ to make sure all sub-datasets have the same info.
         """
-        return len(self._datasets[0].meta.video_keys) > 0
+        return self._datasets[0].meta.info.get("video", False)
 
     @property
     def features(self) -> datasets.Features:

src/lerobot/datasets/pyav_utils.py

@@ -1,311 +0,0 @@
-#!/usr/bin/env python
-
-# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-"""PyAV-based compatibility checks for :class:`VideoEncoderConfig`.
-
-Centralises all :mod:`av` introspection of the bundled FFmpeg build.
-Checks degrade to a no-op when the target codec isn't available locally.
-"""
-
-from __future__ import annotations
-
-import functools
-import logging
-from typing import TYPE_CHECKING, Any, Literal
-
-import av
-import numpy as np
-import torch
-
-from lerobot.datasets.depth_utils import (
-    DEFAULT_DEPTH_MAX,
-    DEFAULT_DEPTH_MIN,
-    DEFAULT_DEPTH_SHIFT,
-    DEFAULT_DEPTH_USE_LOG,
-    quantize_depth,
-    dequantize_depth,
-)
-
-if TYPE_CHECKING:
-    from lerobot.datasets.video_utils import VideoEncoderConfig
-
-logger = logging.getLogger(__name__)
-
-# Pixel formats supported by the depth encode/decode helpers below. Both are
-# 16-bit-word formats that carry 12 significant bits per sample, matching the
-# ``DEPTH_QMAX = 4095`` quantization range.
-DEPTH_PIX_FMTS: tuple[str, ...] = ("yuv420p12le", "gray12le")
-
-# Neutral chroma for 12-bit YUV (the midpoint of [0, 4095]). Filling the U/V
-# planes with this value keeps the encoder from spending bits on chroma noise
-# when only the Y plane carries information.
-_NEUTRAL_CHROMA_12BIT: int = 2048
-
-FFMPEG_NUMERIC_OPTION_TYPES = ("INT", "INT64", "UINT64", "FLOAT", "DOUBLE")
-FFMPEG_INTEGER_OPTION_TYPES = ("INT", "INT64", "UINT64")
-
-
-def _write_u16_plane(plane: av.video.plane.VideoPlane, src: np.ndarray, fill_value: int | None = None) -> None:
-    """Copy ``src`` into a uint16 plane respecting FFmpeg line padding."""
-    height, width = src.shape
-    stride_u16 = plane.line_size // np.dtype(np.uint16).itemsize
-    dst = np.frombuffer(plane, dtype=np.uint16).reshape(height, stride_u16)
-    if fill_value is not None:
-        dst.fill(fill_value)
-    dst[:, :width] = src
-
-
-def encode_depth_frame_pyav(
-    depth: np.ndarray | torch.Tensor,
-    *,
-    pix_fmt: str = "yuv420p12le",
-    depth_min: float = DEFAULT_DEPTH_MIN,
-    depth_max: float = DEFAULT_DEPTH_MAX,
-    shift: float = DEFAULT_DEPTH_SHIFT,
-    use_log: bool = DEFAULT_DEPTH_USE_LOG,
-    input_unit: Literal["auto", "m", "mm"] = "auto",
-) -> av.VideoFrame:
-    """Quantize depth and pack it into a 12-bit PyAV video frame.
-
-    Args:
-        depth: Depth frame to encode (H, W). Unit handling follows
-            :func:`lerobot.datasets.depth_utils.quantize_depth`.
-        pix_fmt: Target pixel format. Must be one of :data:`DEPTH_PIX_FMTS`.
-        depth_min, depth_max, shift, use_log, input_unit: Forwarded to
-            :func:`quantize_depth`.
-
-    Returns:
-        An :class:`av.VideoFrame` in ``pix_fmt`` with quantized depth in the
-        luminance plane.
-    """
-    if pix_fmt not in DEPTH_PIX_FMTS:
-        raise ValueError(f"Unsupported depth pix_fmt={pix_fmt!r}; expected one of {DEPTH_PIX_FMTS}")
-
-    quantized_depth = quantize_depth(
-        depth,
-        depth_min=depth_min,
-        depth_max=depth_max,
-        shift=shift,
-        use_log=use_log,
-        input_unit=input_unit,
-    )
-    if quantized_depth.ndim != 2:
-        raise ValueError(f"depth must be a 2D frame; got shape {quantized_depth.shape}")
-
-    quantized_depth = np.ascontiguousarray(quantized_depth, dtype=np.uint16)
-    height, width = quantized_depth.shape
-
-    if pix_fmt == "gray12le":
-        frame = av.VideoFrame(width=width, height=height, format="gray12le")
-        _write_u16_plane(frame.planes[0], quantized_depth)
-        return frame
-
-    if height % 2 != 0 or width % 2 != 0:
-        raise ValueError("yuv420p12le requires even H and W")
-
-    frame = av.VideoFrame(width=width, height=height, format="yuv420p12le")
-    _write_u16_plane(frame.planes[0], quantized_depth)
-    neutral_chroma = np.full((height // 2, width // 2), _NEUTRAL_CHROMA_12BIT, dtype=np.uint16)
-    _write_u16_plane(frame.planes[1], neutral_chroma, fill_value=_NEUTRAL_CHROMA_12BIT)
-    _write_u16_plane(frame.planes[2], neutral_chroma, fill_value=_NEUTRAL_CHROMA_12BIT)
-    return frame
-
-
-def decode_depth_frame_pyav(
-    frame: av.VideoFrame | list[av.VideoFrame],
-    *,
-    depth_min: float = DEFAULT_DEPTH_MIN,
-    depth_max: float = DEFAULT_DEPTH_MAX,
-    shift: float = DEFAULT_DEPTH_SHIFT,
-    use_log: bool = DEFAULT_DEPTH_USE_LOG,
-    return_quantized: bool = False,
-    output_unit: Literal["m", "mm"] = "m",
-) -> np.ndarray:
-    """Decode one or many depth video frames to quantized or metric depth.
-
-    Args:
-        frame: A single depth frame or a list of depth frames.
-        depth_min, depth_max, shift, use_log: Forwarded to
-            :func:`dequantize_depth`.
-        return_quantized: If ``True``, return raw 12-bit quanta as ``uint16``.
-        output_unit: Unit for dequantized output (``"m"`` or ``"mm"``).
-
-    Returns:
-        ``(H, W)`` array for a single frame, or ``(N, H, W)`` for a list.
-    """
-    frames = frame if isinstance(frame, list) else [frame]
-    quantized = np.stack([f.reformat(format="gray12le").to_ndarray() for f in frames]).astype(np.uint16, copy=False)
-    if return_quantized:
-        return quantized[0] if len(frames) == 1 else quantized
-
-    decoded = dequantize_depth(
-        quantized,
-        depth_min=depth_min,
-        depth_max=depth_max,
-        shift=shift,
-        use_log=use_log,
-        output_unit=output_unit,
-    )
-    return decoded[0] if len(frames) == 1 else decoded
-
-
-@functools.cache
-def get_codec(vcodec: str) -> av.codec.Codec | None:
-    """PyAV write-mode ``Codec`` for *vcodec*, or ``None`` if unavailable."""
-    try:
-        return av.codec.Codec(vcodec, "w")
-    except Exception:
-        return None
-
-
-@functools.cache
-def _get_codec_video_formats(vcodec: str) -> dict[str, av.option.Option]:
-    """Private-option name → PyAV ``Option`` for *vcodec* (empty if unavailable)."""
-    codec = get_codec(vcodec)
-    if codec is None:
-        return {}
-    return {opt.name: opt for opt in codec.descriptor.options}
-
-
-@functools.cache
-def _get_codec_video_formats(vcodec: str) -> tuple[str, ...]:
-    """Pixel formats accepted by *vcodec* in PyAV's preferred order (empty if unknown)."""
-    codec = get_codec(vcodec)
-    if codec is None:
-        return ()
-    return tuple(fmt.name for fmt in (codec.video_formats or []))
-
-
-def detect_available_encoders_pyav(encoders: list[str] | str) -> list[str]:
-    """Return the subset of *encoders* available as video encoders in the local FFmpeg build.
-
-    Each name is probed directly via :func:`get_codec`; input order is preserved.
-    """
-    if isinstance(encoders, str):
-        encoders = [encoders]
-
-    available: list[str] = []
-    for name in encoders:
-        codec = get_codec(name)
-        if codec is not None and codec.type == "video":
-            available.append(name)
-        else:
-            logger.debug("encoder '%s' not available as video encoder", name)
-    return available
-
-
-def _check_option_value(vcodec: str, label: str, value: Any, opt: av.option.Option) -> None:
-    """Range-check numeric *value* and choice-check string *value* against *opt*."""
-    type_name = opt.type.name
-    if type_name in FFMPEG_NUMERIC_OPTION_TYPES:
-        if isinstance(value, bool):
-            raise ValueError(
-                f"{label}={value!r} is not numeric; codec {vcodec!r} expects a number for this option."
-            )
-        elif isinstance(value, str):
-            try:
-                num_val = float(value)
-            except ValueError as e:
-                raise ValueError(
-                    f"{label}={value!r} is not numeric; codec {vcodec!r} expects a number for this option."
-                ) from e
-        elif isinstance(value, (float, int)):
-            num_val = value
-        else:
-            raise ValueError(
-                f"{label}={value!r} is not numeric; codec {vcodec!r} expects a number for this option."
-            )
-
-        # Check integer type compatibility
-        if type_name in FFMPEG_INTEGER_OPTION_TYPES and not num_val.is_integer():
-            raise ValueError(
-                f"{label}={num_val!r} must be an integer for codec {vcodec!r} "
-                f"(FFmpeg option {opt.name!r} is {type_name}); float values are not allowed."
-            )
-
-        # Check numeric range compatibility
-        lo, hi = float(opt.min), float(opt.max)
-        if lo < hi and not (lo <= num_val <= hi):
-            raise ValueError(
-                f"{label}={num_val} is out of range for codec {vcodec!r}; must be in [{lo}, {hi}]"
-            )
-
-    elif type_name == "STRING":
-        if isinstance(value, bool):
-            raise ValueError(f"{label}={value!r} is not a valid string value for codec {vcodec!r}.")
-        if isinstance(value, str):
-            str_val = value
-        elif isinstance(value, (int, float)):
-            str_val = str(value)
-        else:
-            raise ValueError(f"{label}={value!r} has unsupported type for STRING option on codec {vcodec!r}")
-
-        # Check string choice compatibility
-        choices = [c.name for c in (opt.choices or [])]
-        if choices and str_val not in choices:
-            raise ValueError(
-                f"{label}={str_val!r} is not a supported choice for codec "
-                f"{vcodec!r}; valid choices: {choices}"
-            )
-    else:
-        return
-
-
-def _check_pixel_format(vcodec: str, pix_fmt: str) -> None:
-    formats = _get_codec_video_formats(vcodec)
-    if formats and pix_fmt not in formats:
-        raise ValueError(
-            f"pix_fmt={pix_fmt!r} is not supported by codec {vcodec!r}; "
-            f"supported pixel formats: {list(formats)}"
-        )
-
-
-def _check_codec_options(vcodec: str, codec_options: dict[str, Any], config: VideoEncoderConfig) -> None:
-    """Validate merged encoder options (typed) against the codec's published AVOptions."""
-    supported_options = _get_codec_options_by_name(vcodec)
-    for key, value in codec_options.items():
-        # GOP size is not a codec-specific option, it has to be validated separately.
-        if key == "g":
-            if isinstance(value, bool) or not isinstance(value, int) or value < 1:
-                raise ValueError(f"g={value!r} must be a positive integer for codec {vcodec!r}")
-            continue
-        if key not in supported_options:
-            continue
-        opt = supported_options[key]
-        label = f"extra_options[{key!r}]" if key in config.extra_options else key
-        _check_option_value(vcodec, label, value, opt)
-
-
-def check_video_encoder_config_pyav(config: VideoEncoderConfig) -> None:
-    """Verify *config* is compatible with the bundled FFmpeg build.
-
-    Checks pixel format, abstract tuning-field compatibility, and each merged
-    encoder option from :meth:`~lerobot.datasets.video_utils.VideoEncoderConfig.get_codec_options`
-    against PyAV (including numeric ``extra_options`` present in that dict).
-    No-op when ``config.vcodec`` isn't in the local FFmpeg build.
-
-    Raises:
-        ValueError: on the first incompatibility encountered.
-    """
-    vcodec = config.vcodec
-    options = _get_codec_options_by_name(vcodec)
-    if not options:
-        logger.warning(
-            "Codec %r is not available in the bundled FFmpeg build; ",
-            vcodec,
-        )
-        return
-    _check_pixel_format(config.vcodec, config.pix_fmt)
-    _check_codec_options(config.vcodec, config.get_codec_options(), config)

src/lerobot/datasets/streaming_dataset.py

@@ -434,7 +434,7 @@ class StreamingLeRobotDataset(torch.utils.data.IterableDataset):
 
     def _make_padding_camera_frame(self, camera_key: str):
         """Variable-shape padding frame for given camera keys, given in (H, W, C)"""
-        return torch.zeros(self.meta.info.features[camera_key]["shape"]).permute(-1, 0, 1)
+        return torch.zeros(self.meta.info["features"][camera_key]["shape"]).permute(-1, 0, 1)
 
     def _get_video_frame_padding_mask(
         self,

src/lerobot/datasets/utils.py

@@ -14,11 +14,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import contextlib
-import dataclasses
 import importlib.resources
 import json
 import logging
-from dataclasses import dataclass, field
 from pathlib import Path
 
 import datasets
@@ -72,9 +70,6 @@ class ForwardCompatibilityError(CompatibilityError):
         super().__init__(message)
 
 
-logger = logging.getLogger(__name__)
-
-
 DEFAULT_CHUNK_SIZE = 1000  # Max number of files per chunk
 DEFAULT_DATA_FILE_SIZE_IN_MB = 100  # Max size per file
 DEFAULT_VIDEO_FILE_SIZE_IN_MB = 200  # Max size per file
@@ -88,138 +83,16 @@ VIDEO_DIR = "videos"
 
 CHUNK_FILE_PATTERN = "chunk-{chunk_index:03d}/file-{file_index:03d}"
 DEFAULT_TASKS_PATH = "meta/tasks.parquet"
-DEFAULT_SUBTASKS_PATH = "meta/subtasks.parquet"
 DEFAULT_EPISODES_PATH = EPISODES_DIR + "/" + CHUNK_FILE_PATTERN + ".parquet"
 DEFAULT_DATA_PATH = DATA_DIR + "/" + CHUNK_FILE_PATTERN + ".parquet"
 DEFAULT_VIDEO_PATH = VIDEO_DIR + "/{video_key}/" + CHUNK_FILE_PATTERN + ".mp4"
 DEFAULT_IMAGE_PATH = "images/{image_key}/episode-{episode_index:06d}/frame-{frame_index:06d}.png"
-# Depth maps live alongside images on disk but use TIFF instead of PNG: PNG
-# cannot natively round-trip float32, and several common loaders silently
-# downcast 16-bit grayscale.
-DEFAULT_DEPTH_PATH = "images/{image_key}/episode-{episode_index:06d}/frame-{frame_index:06d}.tiff"
 
 LEGACY_EPISODES_PATH = "meta/episodes.jsonl"
 LEGACY_EPISODES_STATS_PATH = "meta/episodes_stats.jsonl"
 LEGACY_TASKS_PATH = "meta/tasks.jsonl"
 
 
-@dataclass
-class DatasetInfo:
-    """Typed representation of the ``meta/info.json`` file for a LeRobot dataset.
-
-    Replaces the previously untyped ``dict`` returned by ``load_info()`` and
-    created by ``create_empty_dataset_info()``.  Using a dataclass provides
-    explicit field definitions, IDE auto-completion, and validation at
-    construction time.
-    """
-
-    codebase_version: str
-    fps: int
-    features: dict[str, dict]
-
-    # Episode / frame counters — start at zero for new datasets
-    total_episodes: int = 0
-    total_frames: int = 0
-    total_tasks: int = 0
-
-    # Storage settings
-    chunks_size: int = field(default=DEFAULT_CHUNK_SIZE)
-    data_files_size_in_mb: int = field(default=DEFAULT_DATA_FILE_SIZE_IN_MB)
-    video_files_size_in_mb: int = field(default=DEFAULT_VIDEO_FILE_SIZE_IN_MB)
-
-    # File path templates
-    data_path: str = field(default=DEFAULT_DATA_PATH)
-    video_path: str | None = field(default=DEFAULT_VIDEO_PATH)
-
-    # Optional metadata
-    robot_type: str | None = None
-    splits: dict[str, str] = field(default_factory=dict)
-
-    def __post_init__(self) -> None:
-        # Coerce feature shapes from list to tuple — JSON deserialisation
-        # returns lists, but the rest of the codebase expects tuples.
-        for ft in self.features.values():
-            if isinstance(ft.get("shape"), list):
-                ft["shape"] = tuple(ft["shape"])
-
-        if self.fps <= 0:
-            raise ValueError(f"fps must be positive, got {self.fps}")
-        if self.chunks_size <= 0:
-            raise ValueError(f"chunks_size must be positive, got {self.chunks_size}")
-        if self.data_files_size_in_mb <= 0:
-            raise ValueError(f"data_files_size_in_mb must be positive, got {self.data_files_size_in_mb}")
-        if self.video_files_size_in_mb <= 0:
-            raise ValueError(f"video_files_size_in_mb must be positive, got {self.video_files_size_in_mb}")
-
-    def to_dict(self) -> dict:
-        """Return a JSON-serialisable dict.
-
-        Converts tuple shapes back to lists so ``json.dump`` can handle them.
-        """
-        d = dataclasses.asdict(self)
-        for ft in d["features"].values():
-            if isinstance(ft.get("shape"), tuple):
-                ft["shape"] = list(ft["shape"])
-        return d
-
-    @classmethod
-    def from_dict(cls, data: dict) -> "DatasetInfo":
-        """Construct from a raw dict (e.g. loaded directly from JSON).
-
-        Unknown keys are ignored for forward compatibility with datasets that
-        carry additional fields (e.g. ``total_videos`` from v2.x). A warning is
-        logged when such fields are present.
-        """
-        known = {f.name for f in dataclasses.fields(cls)}
-        unknown = sorted(k for k in data if k not in known)
-        if unknown:
-            logger.warning(f"Unknown fields in DatasetInfo: {unknown}. These will be ignored.")
-        return cls(**{k: v for k, v in data.items() if k in known})
-
-    # ---------------------------------------------------------------------------
-    # Temporary dict-style compatibility layer
-    # Allows existing ``info["key"]`` call-sites to keep working without changes.
-    # Once all callers have been migrated to attribute access, remove these.
-    # ---------------------------------------------------------------------------
-    def __getitem__(self, key: str):
-        import warnings
-
-        warnings.warn(
-            f"Accessing DatasetInfo with dict-style syntax info['{key}'] is deprecated. "
-            f"Use attribute access info.{key} instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        try:
-            return getattr(self, key)
-        except AttributeError as err:
-            raise KeyError(key) from err
-
-    def __setitem__(self, key: str, value) -> None:
-        import warnings
-
-        warnings.warn(
-            f"Setting DatasetInfo with dict-style syntax info['{key}'] = ... is deprecated. "
-            f"Use attribute assignment info.{key} = ... instead.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        if not hasattr(self, key):
-            raise KeyError(f"DatasetInfo has no field '{key}'")
-        setattr(self, key, value)
-
-    def __contains__(self, key: str) -> bool:
-        """Check if a field exists (dict-like interface)."""
-        return hasattr(self, key)
-
-    def get(self, key: str, default=None):
-        """Get attribute value with default fallback (dict-like interface)."""
-        try:
-            return getattr(self, key)
-        except AttributeError:
-            return default
-
-
 def has_legacy_hub_download_metadata(root: Path) -> bool:
     """Return ``True`` when *root* looks like a legacy Hub ``local_dir`` mirror.
 
@@ -420,7 +293,7 @@ def create_branch(repo_id: str, *, branch: str, repo_type: str | None = None) ->
 
 def create_lerobot_dataset_card(
     tags: list | None = None,
-    dataset_info: DatasetInfo | None = None,
+    dataset_info: dict | None = None,
     **kwargs,
 ) -> DatasetCard:
     """Create a `DatasetCard` for a LeRobot dataset.
@@ -431,7 +304,7 @@ def create_lerobot_dataset_card(
 
     Args:
         tags (list | None): A list of tags to add to the dataset card.
-        dataset_info (DatasetInfo | None): The dataset's info object, which will
+        dataset_info (dict | None): The dataset's info dictionary, which will
             be displayed on the card.
         **kwargs: Additional keyword arguments to populate the card template.
 
@@ -444,7 +317,7 @@ def create_lerobot_dataset_card(
         card_tags += tags
     if dataset_info:
         dataset_structure = "[meta/info.json](meta/info.json):\n"
-        dataset_structure += f"```json\n{json.dumps(dataset_info.to_dict(), indent=4)}\n```\n"
+        dataset_structure += f"```json\n{json.dumps(dataset_info, indent=4)}\n```\n"
         kwargs = {**kwargs, "dataset_structure": dataset_structure}
     card_data = DatasetCardData(
         license=kwargs.get("license"),

src/lerobot/datasets/video_utils.py

@@ -17,13 +17,12 @@ import contextlib
 import glob
 import importlib
 import logging
-import math
 import queue
 import shutil
 import tempfile
 import threading
 import warnings
-from dataclasses import asdict, dataclass, field
+from dataclasses import dataclass, field
 from fractions import Fraction
 from pathlib import Path
 from threading import Lock
@@ -38,23 +37,7 @@ import torchvision
 from datasets.features.features import register_feature
 from PIL import Image
 
-from lerobot.datasets.pyav_utils import (
-    check_video_encoder_config_pyav,
-    depth_to_video_frame,
-    detect_available_encoders_pyav,
-    decode_depth_frame,
-    encode_depth_frame_pyav,
-    decode_depth_frame_pyav,
-)
-from lerobot.datasets.depth_utils import (
-    quantize_depth,
-    dequantize_depth,
-    DEFAULT_DEPTH_MIN,
-    DEFAULT_DEPTH_MAX,
-    DEFAULT_DEPTH_SHIFT,
-    DEFAULT_DEPTH_USE_LOG,
-)
-from lerobot.utils.import_utils import get_safe_default_video_backend
+from lerobot.utils.import_utils import get_safe_default_codec
 
 logger = logging.getLogger(__name__)
 
@@ -69,226 +52,70 @@ HW_ENCODERS = [
     "h264_qsv",  # Intel Quick Sync
 ]
 
-VALID_VIDEO_CODECS = {"h264", "hevc", "libsvtav1", "ffv1", "auto"} | set(HW_ENCODERS)
-
-LIBSVTAV1_DEFAULT_PRESET: int = 12
+VALID_VIDEO_CODECS = {"h264", "hevc", "libsvtav1", "auto"} | set(HW_ENCODERS)
 
 
-@dataclass
-class VideoEncoderConfig:
-    """Video encoder configuration.
+def _get_codec_options(
+    vcodec: str,
+    g: int | None = 2,
+    crf: int | None = 30,
+    preset: int | None = None,
+) -> dict:
+    """Build codec-specific options dict for video encoding."""
+    options = {}
 
-    Attributes:
-        vcodec: FFmpeg encoder name. ``"auto"`` is resolved during
-            construction (HW encoder if available, else ``libsvtav1``).
-        pix_fmt: Pixel format (e.g. ``"yuv420p"``).
-        g: GOP size (keyframe interval).
-        crf: Quality level — mapped to the native quality parameter of the
-            codec (``crf`` for software, ``qp`` for NVENC/VAAPI,
-            ``q:v`` for VideoToolbox, ``global_quality`` for QSV).
-        preset: Speed/quality preset. Accepted type is per-codec.
-        fast_decode: Fast-decode tuning. For ``libsvtav1`` this is a level (0-2)
-            embedded in ``svtav1-params``. For ``h264`` and ``hevc`` non-zero values
-            set ``tune=fastdecode``. Ignored for other codecs.
-        video_backend: Python library driving FFmpeg for encoding. Only ``"pyav"``
-            is currently supported.
-        extra_options: Free-form dictionary of additional FFmpeg options
-            (e.g. ``{"tune": "film", "profile:v": "high", "bf": 2}``).
-    """
+    # GOP size (keyframe interval) - supported by VideoToolbox and software encoders
+    if g is not None and (vcodec in ("h264_videotoolbox", "hevc_videotoolbox") or vcodec not in HW_ENCODERS):
+        options["g"] = str(g)
 
-    vcodec: str = "libsvtav1"
-    pix_fmt: str = "yuv420p"
-    g: int | None = 2
-    crf: int | None = 30
-    preset: int | str | None = None
-    fast_decode: int = 0
-    # TODO(CarolinePascal): add torchcodec support + find a way to unify the
-    # two backends (encoding and decoding).
-    video_backend: str = "pyav"
-    extra_options: dict[str, Any] = field(default_factory=dict)
+    # Quality control (codec-specific parameter names)
+    if crf is not None:
+        if vcodec in ("h264", "hevc", "libsvtav1"):
+            options["crf"] = str(crf)
+        elif vcodec in ("h264_videotoolbox", "hevc_videotoolbox"):
+            quality = max(1, min(100, int(100 - crf * 2)))
+            options["q:v"] = str(quality)
+        elif vcodec in ("h264_nvenc", "hevc_nvenc"):
+            options["rc"] = "constqp"
+            options["qp"] = str(crf)
+        elif vcodec in ("h264_vaapi",):
+            options["qp"] = str(crf)
+        elif vcodec in ("h264_qsv",):
+            options["global_quality"] = str(crf)
 
-    # Class-level marker persisted to ``info.json`` (via ``asdict``) so the
-    # reader can tell depth datasets from RGB ones without a separate dispatch
-    # path. ``init=False`` keeps it out of CLI/constructor surface; subclasses
-    # flip the default (see :class:`DepthEncoderConfig`).
-    is_depth_map: bool = field(default=False, init=False)
+    # Preset (only for libsvtav1)
+    if vcodec == "libsvtav1":
+        options["preset"] = str(preset) if preset is not None else "12"
 
-    def __post_init__(self) -> None:
-        self.resolve_vcodec()
-
-        # Empty-constructor ergonomics: ``VideoEncoderConfig()`` must "just work".
-        if self.preset is None and self.vcodec == "libsvtav1":
-            self.preset = LIBSVTAV1_DEFAULT_PRESET
-
-        self.validate()
-
-    def detect_available_encoders(self, encoders: list[str] | str) -> list[str]:
-        """Detect available encoders based on the video backend."""
-        if self.video_backend == "pyav":
-            return detect_available_encoders_pyav(encoders)
-        else:
-            return []
-
-    def validate(self) -> None:
-        """Validate the video encoder config."""
-        if self.video_backend == "pyav":
-            check_video_encoder_config_pyav(self)
-
-    def resolve_vcodec(self) -> None:
-        """Validate vcodec and resolve 'auto' to best available HW encoder, fallback to libsvtav1.
-
-        Any explicitly-requested codec that isn't in the local FFmpeg build is
-        also silently rewritten to ``libsvtav1`` so encoding never hard-fails on
-        a host missing the requested encoder.
-        """
-        # Backward compatibility: older datasets persist ``vcodec="av1"`` in
-        # ``info.json``. Rewrite to the canonical encoder name *before* the
-        # validation check below so loading those datasets keeps working.
-        if self.vcodec == "av1":
-            self.vcodec = "libsvtav1"
-
-        if self.vcodec not in VALID_VIDEO_CODECS:
-            raise ValueError(f"Invalid vcodec '{self.vcodec}'. Must be one of: {sorted(VALID_VIDEO_CODECS)}")
-        if self.vcodec == "auto":
-            available = self.detect_available_encoders(HW_ENCODERS)
-            for encoder in HW_ENCODERS:
-                if encoder in available:
-                    logger.info(f"Auto-selected video codec: {encoder}")
-                    self.vcodec = encoder
-                    return
-            logger.info("No hardware encoder available, falling back to software encoder 'libsvtav1'")
-            self.vcodec = "libsvtav1"
-
-        if self.detect_available_encoders(self.vcodec):
-            logger.info(f"Using video codec: {self.vcodec}")
-            self.vcodec = self.vcodec
-            return
-        raise ValueError(f"Unsupported video codec: {self.vcodec} with video backend {self.video_backend}")
-
-    def get_codec_options(
-        self, encoder_threads: int | None = None, as_strings: bool = False
-    ) -> dict[str, str]:
-        """Translate the tuning fields to codec-specific FFmpeg options.
-
-        ``VideoEncoderConfig.extra_options`` are merged last but never override a structured field.
-
-        Args:
-            encoder_threads: Number of encoder threads set globally for all VideoEncoderConfigs.
-                For libsvtav1, this is mapped to ``lp`` via ``svtav1-params``.
-                For h264/hevc, this is mapped to ``threads``.
-                Hardware encoders ignore this parameter.
-            as_strings: If ``True``, casts values to strings.
-        """
-        opts: dict[str, Any] = {}
-
-        def set_if(key: str, value: Any) -> None:
-            if value is not None:
-                opts[key] = value if not as_strings else str(value)
-
-        # GOP size is not a codec-specific option, so it is always set.
-        set_if("g", self.g)
-
-        if self.vcodec == "libsvtav1":
-            set_if("crf", self.crf)
-            set_if("preset", self.preset)
-            svtav1_parts: list[str] = []
-            if self.fast_decode is not None:
-                svtav1_parts.append(f"fast-decode={max(0, min(2, self.fast_decode))}")
-            if encoder_threads is not None:
-                svtav1_parts.append(f"lp={encoder_threads}")
-            if svtav1_parts:
-                opts["svtav1-params"] = ":".join(svtav1_parts)
-        elif self.vcodec in ("h264", "hevc"):
-            set_if("crf", self.crf)
-            set_if("preset", self.preset)
-            if self.fast_decode:
-                opts["tune"] = "fastdecode"
-            set_if("threads", encoder_threads)
-        elif self.vcodec in ("h264_videotoolbox", "hevc_videotoolbox"):
-            if self.crf is not None:
-                opts["q:v"] = max(1, min(100, 100 - self.crf * 2))
-        elif self.vcodec in ("h264_nvenc", "hevc_nvenc"):
-            opts["rc"] = "constqp"
-            set_if("qp", self.crf)
-            set_if("preset", self.preset)
-        elif self.vcodec == "h264_vaapi":
-            set_if("qp", self.crf)
-        elif self.vcodec == "h264_qsv":
-            set_if("global_quality", self.crf)
-            set_if("preset", self.preset)
-        elif self.vcodec == "ffv1":
-            # Lossless intra-frame codec. ``crf``/``preset``/``fast_decode`` 
-            # are not meaningful.
-            set_if("threads", encoder_threads)
-        else:
-            set_if("crf", self.crf)
-            set_if("preset", self.preset)
-
-        # Extra options are merged last but never override structured fields (values are kept as given).
-        for k, v in self.extra_options.items():
-            if k not in opts:
-                set_if(k, v)
-
-        return opts
+    return options
 
 
-@dataclass
-class DepthEncoderConfig(VideoEncoderConfig):
-    """Encoder configuration for depth-map streams.
-
-    Inherits the full :class:`VideoEncoderConfig` surface (codec, GOP, CRF,
-    preset, ``extra_options``…) and adds the four parameters of the depth
-    quantization pipeline (:func:`quantize_depth`). Inheritance — rather
-    than composition — keeps the CLI flat: ``--dataset.depth_encoder_config.<field>``
-    works identically to its RGB counterpart.
-
-    Defaults flip ``vcodec`` to ``"hevc"`` (Main 12 profile) and ``pix_fmt``
-    to ``"yuv420p12le"``, the most widely available 12-bit pixel format.
-    For archive-grade lossless storage use ``vcodec="ffv1"`` together with
-    ``pix_fmt="gray12le"`` (and clear ``crf``/``preset`` to ``None`` since
-    ``ffv1`` doesn't expose those tuning knobs).
-
-    The :attr:`is_depth_map` marker is class-fixed to ``True`` (``init=False``,
-    so it's hidden from CLI and constructor args) and is what the reader
-    side keys on to tell depth datasets from RGB ones.
-
-    Attributes:
-        depth_min: Minimum depth in physical units (e.g. metres) represented
-            by quantum ``0``.
-        depth_max: Maximum depth represented by quantum :data:`DEPTH_QMAX`.
-        shift: Pre-log offset for numerical stability near zero.
-        use_log: ``True`` for logarithmic quantization (default; matches
-            sensor error profile), ``False`` for linear.
-    """
-
-    vcodec: str = "hevc"
-    pix_fmt: str = "yuv420p12le"
-
-    depth_min: float = DEFAULT_DEPTH_MIN
-    depth_max: float = DEFAULT_DEPTH_MAX
-    shift: float = DEFAULT_DEPTH_SHIFT
-    use_log: bool = DEFAULT_DEPTH_USE_LOG
-
-    # Class invariant — kept out of ``__init__`` (and CLI) but persisted
-    # via ``asdict`` into ``info.json`` for the reader to detect depth.
-    is_depth_map: bool = field(default=True, init=False)
-
-    def quantize(self, depth: torch.Tensor | np.ndarray) -> torch.Tensor:
-        """Apply :func:`quantize_depth` bound to this config's parameters."""
-        return quantize_depth(depth, self.depth_min, self.depth_max, self.shift, self.use_log)
-
-    def dequantize(self, quantized: torch.Tensor | np.ndarray) -> torch.Tensor:
-        """Apply :func:`dequantize_depth` bound to this config's parameters."""
-        return dequantize_depth(quantized, self.depth_min, self.depth_max, self.shift, self.use_log)
+def detect_available_hw_encoders() -> list[str]:
+    """Probe PyAV/FFmpeg for available hardware video encoders."""
+    available = []
+    for codec_name in HW_ENCODERS:
+        try:
+            av.codec.Codec(codec_name, "w")
+            available.append(codec_name)
+        except Exception:  # nosec B110
+            logger.debug("HW encoder '%s' not available", codec_name)  # nosec B110
+    return available
 
 
-def depth_encoder_defaults() -> DepthEncoderConfig:
-    """Return a :class:`DepthEncoderConfig` with depth-camera defaults."""
-    return DepthEncoderConfig()
-
-def camera_encoder_defaults() -> VideoEncoderConfig:
-    """Return a :class:`VideoEncoderConfig` with RGB-camera defaults."""
-    return VideoEncoderConfig()
+def resolve_vcodec(vcodec: str) -> str:
+    """Validate vcodec and resolve 'auto' to best available HW encoder, fallback to libsvtav1."""
+    if vcodec not in VALID_VIDEO_CODECS:
+        raise ValueError(f"Invalid vcodec '{vcodec}'. Must be one of: {sorted(VALID_VIDEO_CODECS)}")
+    if vcodec != "auto":
+        logger.info(f"Using video codec: {vcodec}")
+        return vcodec
+    available = detect_available_hw_encoders()
+    for encoder in HW_ENCODERS:
+        if encoder in available:
+            logger.info(f"Auto-selected video codec: {encoder}")
+            return encoder
+    logger.info("No hardware encoder available, falling back to software encoder 'libsvtav1'")
+    return "libsvtav1"
 
 
 def decode_video_frames(
@@ -315,7 +142,7 @@ def decode_video_frames(
     Currently supports torchcodec on cpu and pyav.
     """
     if backend is None:
-        backend = get_safe_default_video_backend()
+        backend = get_safe_default_codec()
     if backend == "torchcodec":
         return decode_video_frames_torchcodec(video_path, timestamps, tolerance_s, return_uint8=return_uint8)
     elif backend in ["pyav", "video_reader"]:
@@ -569,136 +396,22 @@ def decode_video_frames_torchcodec(
     return closest_frames
 
 
-def decode_depth_frames(
-    video_path: Path | str,
-    timestamps: list[float],
-    tolerance_s: float,
-    *,
-    depth_min: float = DEFAULT_DEPTH_MIN,
-    depth_max: float = DEFAULT_DEPTH_MAX,
-    shift: float = DEFAULT_DEPTH_SHIFT,
-    use_log: bool = DEFAULT_DEPTH_USE_LOG,
-    return_quantized: bool = False,
-    log_loaded_timestamps: bool = False,
-) -> torch.Tensor:
-    """Decode depth-map frames at the requested timestamps using PyAV.
-
-    Mirrors the timestamp-tolerance / closest-frame contract of
-    :func:`decode_video_frames` but operates entirely through PyAV (the
-    ``torchvision`` and ``torchcodec`` backends don't currently round-trip
-    12-bit pixel formats reliably).
-
-    Each decoded frame is reformatted to ``gray12le`` so the same path
-    handles ``yuv420p12le`` (HEVC default) and ``gray12le`` (ffv1 archive)
-    sources transparently.
-
-    Args:
-        video_path: Path to a depth video produced with a
-            :class:`DepthEncoderConfig`.
-        timestamps: Frame timestamps to retrieve, in seconds.
-        tolerance_s: Maximum allowed deviation between the queried and the
-            actually-decoded timestamps.
-        depth_min, depth_max, shift, use_log: Parameters used at quantization
-            time. Should match :func:`info_to_depth_kwargs` extracted from
-            ``info.json`` for the source dataset.
-        return_quantized: If ``True``, skip the dequantization step and
-            return raw 12-bit ``uint16`` quanta.
-        log_loaded_timestamps: Debug logging.
-
-    Returns:
-        ``torch.Tensor`` of shape ``(N, H, W)``:
-
-        * ``dtype=torch.float32`` (metric depth, default)
-        * ``dtype=torch.uint16`` when ``return_quantized=True``.
-
-    Raises:
-        FrameTimestampError: If a query timestamp can't be matched within
-            *tolerance_s*, or if no frames are decoded.
-    """
-    video_path_str = str(video_path)
-    first_ts = min(timestamps)
-    last_ts = max(timestamps)
-
-    loaded_frames: list[np.ndarray] = []
-    loaded_ts: list[float] = []
-
-    av.logging.set_level(av.logging.WARNING)
-    with av.open(video_path_str, "r") as container:
-        try:
-            stream = container.streams.video[0]
-        except IndexError as e:
-            raise FrameTimestampError(f"No video stream in {video_path_str}") from e
-
-        # Seek to the keyframe at-or-before first_ts (PyAV doesn't do
-        # accurate seek, so we still iterate forward to the requested range).
-        seek_pts = int(first_ts / stream.time_base)
-        container.seek(seek_pts, stream=stream, any_frame=False, backward=True)
-
-        for frame in container.decode(stream):
-            if frame.pts is None:
-                continue
-            current_ts = float(frame.pts * stream.time_base)
-            if log_loaded_timestamps:
-                logger.info(f"depth frame loaded at timestamp={current_ts:.4f}")
-            loaded_frames.append(
-                decode_depth_frame(
-                    frame,
-                    depth_min=depth_min,
-                    depth_max=depth_max,
-                    shift=shift,
-                    use_log=use_log,
-                    return_quantized=True,
-                )
-            )
-            loaded_ts.append(current_ts)
-            if current_ts >= last_ts:
-                break
-
-    av.logging.restore_default_callback()
-
-    if not loaded_frames:
-        raise FrameTimestampError(
-            f"No depth frames decoded from {video_path_str} for timestamps {timestamps}"
-        )
-
-    query_ts = torch.tensor(timestamps)
-    loaded_ts_t = torch.tensor(loaded_ts)
-    dist = torch.cdist(query_ts[:, None], loaded_ts_t[:, None], p=1)
-    min_, argmin_ = dist.min(1)
-
-    is_within_tol = min_ < tolerance_s
-    if not is_within_tol.all():
-        raise FrameTimestampError(
-            f"One or several query timestamps violate the tolerance "
-            f"({min_[~is_within_tol]} > {tolerance_s=})."
-            f"\nqueried timestamps: {query_ts}"
-            f"\nloaded timestamps: {loaded_ts_t}"
-            f"\nvideo: {video_path_str}"
-        )
-
-    closest = np.stack([loaded_frames[i] for i in argmin_])  # (N, H, W) uint16
-    quantized = torch.from_numpy(closest)
-
-    if return_quantized:
-        return quantized
-    return dequantize_depth(quantized, depth_min, depth_max, shift, use_log)
-
-
 def encode_video_frames(
     imgs_dir: Path | str,
     video_path: Path | str,
     fps: int,
-    camera_encoder_config: VideoEncoderConfig | None = None,
-    encoder_threads: int | None = None,
-    *,
+    vcodec: str = "libsvtav1",
+    pix_fmt: str = "yuv420p",
+    g: int | None = 2,
+    crf: int | None = 30,
+    fast_decode: int = 0,
     log_level: int | None = av.logging.WARNING,
     overwrite: bool = False,
+    preset: int | None = None,
+    encoder_threads: int | None = None,
 ) -> None:
     """More info on ffmpeg arguments tuning on `benchmark/video/README.md`"""
-    if camera_encoder_config is None:
-        camera_encoder_config = VideoEncoderConfig()
-    vcodec = camera_encoder_config.vcodec
-    pix_fmt = camera_encoder_config.pix_fmt
+    vcodec = resolve_vcodec(vcodec)
 
     video_path = Path(video_path)
     imgs_dir = Path(imgs_dir)
@@ -709,18 +422,42 @@ def encode_video_frames(
 
     video_path.parent.mkdir(parents=True, exist_ok=True)
 
+    # Encoders/pixel formats incompatibility check
+    if (vcodec == "libsvtav1" or vcodec == "hevc") and pix_fmt == "yuv444p":
+        logger.warning(
+            f"Incompatible pixel format 'yuv444p' for codec {vcodec}, auto-selecting format 'yuv420p'"
+        )
+        pix_fmt = "yuv420p"
+
     # Get input frames
     template = "frame-" + ("[0-9]" * 6) + ".png"
     input_list = sorted(
         glob.glob(str(imgs_dir / template)), key=lambda x: int(x.split("-")[-1].split(".")[0])
     )
 
+    # Define video output frame size (assuming all input frames are the same size)
     if len(input_list) == 0:
         raise FileNotFoundError(f"No images found in {imgs_dir}.")
     with Image.open(input_list[0]) as dummy_image:
         width, height = dummy_image.size
 
-    video_options = camera_encoder_config.get_codec_options(encoder_threads, as_strings=True)
+    # Define video codec options
+    video_options = _get_codec_options(vcodec, g, crf, preset)
+
+    if fast_decode:
+        key = "svtav1-params" if vcodec == "libsvtav1" else "tune"
+        value = f"fast-decode={fast_decode}" if vcodec == "libsvtav1" else "fastdecode"
+        video_options[key] = value
+
+    if encoder_threads is not None:
+        if vcodec == "libsvtav1":
+            lp_param = f"lp={encoder_threads}"
+            if "svtav1-params" in video_options:
+                video_options["svtav1-params"] += f":{lp_param}"
+            else:
+                video_options["svtav1-params"] = lp_param
+        else:
+            video_options["threads"] = str(encoder_threads)
 
     # Set logging level
     if log_level is not None:
@@ -757,10 +494,7 @@ def encode_video_frames(
 
 
 def concatenate_video_files(
-    input_video_paths: list[Path | str],
-    output_video_path: Path,
-    overwrite: bool = True,
-    compatibility_check: bool = False,
+    input_video_paths: list[Path | str], output_video_path: Path, overwrite: bool = True
 ):
     """
     Concatenate multiple video files into a single video file using pyav.
@@ -773,7 +507,6 @@ def concatenate_video_files(
         input_video_paths: Ordered list of input video file paths to concatenate.
         output_video_path: Path to the output video file.
         overwrite: Whether to overwrite the output video file if it already exists. Default is True.
-        compatibility_check: Whether to check if the input videos are compatible. Default is False.
 
     Note:
         - Creates a temporary directory for intermediate files that is cleaned up after use.
@@ -792,22 +525,6 @@ def concatenate_video_files(
     if len(input_video_paths) == 0:
         raise FileNotFoundError("No input video paths provided.")
 
-    # This check may be skipped at recording time as videos are encoded with the same encoder config.
-    if compatibility_check:
-        reference_video_info = get_video_info(input_video_paths[0])
-        for input_path in input_video_paths[1:]:
-            video_info = get_video_info(input_path)
-            if (
-                video_info["video.height"] != reference_video_info["video.height"]
-                or video_info["video.width"] != reference_video_info["video.width"]
-                or video_info["video.fps"] != reference_video_info["video.fps"]
-                or video_info["video.codec"] != reference_video_info["video.codec"]
-                or video_info["video.pix_fmt"] != reference_video_info["video.pix_fmt"]
-            ):
-                raise ValueError(
-                    f"Input video {input_path} is not compatible with the reference video {input_video_paths[0]}."
-                )
-
     # Create a temporary .ffconcat file to list the input video paths
     with tempfile.NamedTemporaryFile(mode="w", suffix=".ffconcat", delete=False) as tmp_concatenate_file:
         tmp_concatenate_file.write("ffconcat version 1.0\n")
@@ -874,31 +591,33 @@ class _CameraEncoderThread(threading.Thread):
         fps: int,
         vcodec: str,
         pix_fmt: str,
-        codec_options: dict[str, str],
+        g: int | None,
+        crf: int | None,
+        preset: int | None,
         frame_queue: queue.Queue,
         result_queue: queue.Queue,
         stop_event: threading.Event,
-        depth_encoder_config: "DepthEncoderConfig | None" = None,
+        encoder_threads: int | None = None,
     ):
         super().__init__(daemon=True)
         self.video_path = video_path
         self.fps = fps
         self.vcodec = vcodec
         self.pix_fmt = pix_fmt
-        self.codec_options = codec_options
+        self.g = g
+        self.crf = crf
+        self.preset = preset
         self.frame_queue = frame_queue
         self.result_queue = result_queue
         self.stop_event = stop_event
-        self.depth_encoder_config = depth_encoder_config
-
+        self.encoder_threads = encoder_threads
 
     def run(self) -> None:
         from .compute_stats import RunningQuantileStats, auto_downsample_height_width
 
         container = None
         output_stream = None
-        is_depth = self.depth_encoder_config is not None
-        stats_tracker = RunningQuantileStats() if not is_depth else None
+        stats_tracker = RunningQuantileStats()
         frame_count = 0
 
         try:
@@ -916,45 +635,51 @@ class _CameraEncoderThread(threading.Thread):
                     # Sentinel: flush and close
                     break
 
-                # Ensure HWC (RGB or depth) uint8 (RGB only) numpy array
+                # Ensure HWC uint8 numpy array
                 if isinstance(frame_data, np.ndarray):
                     if frame_data.ndim == 3 and frame_data.shape[0] == 3:
                         # CHW -> HWC
                         frame_data = frame_data.transpose(1, 2, 0)
-                    if frame_data.dtype != np.uint8 and not is_depth:
+                    if frame_data.dtype != np.uint8:
                         frame_data = (frame_data * 255).astype(np.uint8)
 
                 # Open container on first frame (to get width/height)
                 if container is None:
                     height, width = frame_data.shape[:2]
+                    video_options = _get_codec_options(self.vcodec, self.g, self.crf, self.preset)
+                    if self.encoder_threads is not None:
+                        if self.vcodec == "libsvtav1":
+                            lp_param = f"lp={self.encoder_threads}"
+                            if "svtav1-params" in video_options:
+                                video_options["svtav1-params"] += f":{lp_param}"
+                            else:
+                                video_options["svtav1-params"] = lp_param
+                        else:
+                            video_options["threads"] = str(self.encoder_threads)
                     Path(self.video_path).parent.mkdir(parents=True, exist_ok=True)
                     container = av.open(str(self.video_path), "w")
-                    output_stream = container.add_stream(self.vcodec, self.fps, options=self.codec_options)
+                    output_stream = container.add_stream(self.vcodec, self.fps, options=video_options)
                     output_stream.pix_fmt = self.pix_fmt
                     output_stream.width = width
                     output_stream.height = height
                     output_stream.time_base = Fraction(1, self.fps)
 
                 # Encode frame with explicit timestamps
-                if is_depth:
-                    video_frame = encode_depth_frame_pyav(frame_data, pix_fmt=self.pix_fmt, depth_min=self.depth_encoder_config.depth_min, depth_max=self.depth_encoder_config.depth_max, shift=self.depth_encoder_config.shift, use_log=self.depth_encoder_config.use_log)
-                else:
-                    pil_img = Image.fromarray(frame_data)
-                    video_frame = av.VideoFrame.from_image(pil_img)
+                pil_img = Image.fromarray(frame_data)
+                video_frame = av.VideoFrame.from_image(pil_img)
                 video_frame.pts = frame_count
                 video_frame.time_base = Fraction(1, self.fps)
                 packet = output_stream.encode(video_frame)
                 if packet:
                     container.mux(packet)
 
-                if not is_depth:
-                    # Update stats with downsampled frame (per-channel stats like compute_episode_stats)
-                    img_chw = frame_data.transpose(2, 0, 1)  # HWC -> CHW
-                    img_downsampled = auto_downsample_height_width(img_chw)
-                    # Reshape CHW to (H*W, C) for per-channel stats
-                    channels = img_downsampled.shape[0]
-                    img_for_stats = img_downsampled.transpose(1, 2, 0).reshape(-1, channels)
-                    stats_tracker.update(img_for_stats)
+                # Update stats with downsampled frame (per-channel stats like compute_episode_stats)
+                img_chw = frame_data.transpose(2, 0, 1)  # HWC -> CHW
+                img_downsampled = auto_downsample_height_width(img_chw)
+                # Reshape CHW to (H*W, C) for per-channel stats
+                channels = img_downsampled.shape[0]
+                img_for_stats = img_downsampled.transpose(1, 2, 0).reshape(-1, channels)
+                stats_tracker.update(img_for_stats)
 
                 frame_count += 1
 
@@ -969,10 +694,8 @@ class _CameraEncoderThread(threading.Thread):
 
             av.logging.restore_default_callback()
 
-            # Get stats and put on result queue (depth streams skip stats)
-            if is_depth:
-                self.result_queue.put(("ok", None))
-            elif frame_count >= 2:
+            # Get stats and put on result queue
+            if frame_count >= 2:
                 stats = stats_tracker.get_statistics()
                 self.result_queue.put(("ok", stats))
             else:
@@ -1001,40 +724,22 @@ class StreamingVideoEncoder:
     def __init__(
         self,
         fps: int,
-        camera_encoder_config: VideoEncoderConfig | None = None,
-        encoder_threads: int | None = None,
-        *,
+        vcodec: str = "libsvtav1",
+        pix_fmt: str = "yuv420p",
+        g: int | None = 2,
+        crf: int | None = 30,
+        preset: int | None = None,
         queue_maxsize: int = 30,
-        depth_encoder_config: "DepthEncoderConfig | None" = None,
-        depth_keys: list[str] | None = None,
+        encoder_threads: int | None = None,
     ):
-        """
-        Args:
-            fps: Frames per second for the output videos.
-            camera_encoder_config: Video encoder settings applied to all cameras.
-                When ``None``, :class:`VideoEncoderConfig` defaults are used.
-            encoder_threads: Number of encoder threads (global setting).
-                ``None`` lets the codec decide.
-            queue_maxsize: Max frames to buffer per camera before
-                back-pressure drops frames.
-            depth_encoder_config: Optional depth encoder configuration applied
-                to all depth video keys listed in ``depth_keys``.
-            depth_keys: Video keys (matching the dataset feature names) that
-                must be encoded as quantized depth maps using
-                ``depth_encoder_config``. Required when ``depth_encoder_config``
-                is provided.
-        """
         self.fps = fps
-        self._camera_encoder_config = camera_encoder_config or VideoEncoderConfig()
-        self._encoder_threads = encoder_threads
+        self.vcodec = resolve_vcodec(vcodec)
+        self.pix_fmt = pix_fmt
+        self.g = g
+        self.crf = crf
+        self.preset = preset
         self.queue_maxsize = queue_maxsize
-        self._depth_encoder_config = depth_encoder_config
-        self._depth_keys: set[str] = set(depth_keys or [])
-        if self._depth_keys and self._depth_encoder_config is None:
-            raise ValueError(
-                "StreamingVideoEncoder received depth_keys without a depth_encoder_config; "
-                "either pass a DepthEncoderConfig or remove depth_keys."
-            )
+        self.encoder_threads = encoder_threads
 
         self._frame_queues: dict[str, queue.Queue] = {}
         self._result_queues: dict[str, queue.Queue] = {}
@@ -1065,28 +770,18 @@ class StreamingVideoEncoder:
             temp_video_dir = Path(tempfile.mkdtemp(dir=temp_dir))
             video_path = temp_video_dir / f"{video_key.replace('/', '_')}_streaming.mp4"
 
-            is_depth_key = video_key in self._depth_keys
-            encoder_cfg: VideoEncoderConfig
-            depth_cfg = None
-            if is_depth_key:
-                assert self._depth_encoder_config is not None  # guaranteed by __init__
-                encoder_cfg = self._depth_encoder_config
-                depth_cfg = self._depth_encoder_config
-            else:
-                encoder_cfg = self._camera_encoder_config
-
-            vcodec = encoder_cfg.vcodec
-            codec_options = encoder_cfg.get_codec_options(self._encoder_threads)
             encoder_thread = _CameraEncoderThread(
                 video_path=video_path,
                 fps=self.fps,
-                vcodec=vcodec,
-                pix_fmt=encoder_cfg.pix_fmt,
-                codec_options=codec_options,
+                vcodec=self.vcodec,
+                pix_fmt=self.pix_fmt,
+                g=self.g,
+                crf=self.crf,
+                preset=self.preset,
                 frame_queue=frame_queue,
                 result_queue=result_queue,
                 stop_event=stop_event,
-                depth_encoder_config=depth_cfg,
+                encoder_threads=self.encoder_threads,
             )
             encoder_thread.start()
 
@@ -1291,18 +986,8 @@ def get_audio_info(video_path: Path | str) -> dict:
     return audio_info
 
 
-def get_video_info(
-    video_path: Path | str,
-    video_encoder_config: "VideoEncoderConfig | None" = None,
-) -> dict:
-    """Build the ``video.*`` / ``audio.*`` info dict persisted in ``info.json``.
-
-    Args:
-        video_path: Path to the encoded video file to probe.
-        video_encoder_config: If provided, record the exact encoder settings used to encode this
-            video. Stream-derived values take precedence — encoder fields are only written for keys
-            not already populated from the video file itself.
-    """
+def get_video_info(video_path: Path | str) -> dict:
+    # Set logging level
     logging.getLogger("libav").setLevel(av.logging.WARNING)
 
     # Getting video stream information
@@ -1319,6 +1004,7 @@ def get_video_info(
         video_info["video.width"] = video_stream.width
         video_info["video.codec"] = video_stream.codec.canonical_name
         video_info["video.pix_fmt"] = video_stream.pix_fmt
+        video_info["video.is_depth_map"] = False
 
         # Calculate fps from r_frame_rate
         video_info["video.fps"] = int(video_stream.base_rate)
@@ -1332,67 +1018,9 @@ def get_video_info(
     # Adding audio stream information
     video_info.update(**get_audio_info(video_path))
 
-    # Add additional encoder configuration if provided (no override of stream-derived values)
-    # Depth related fields flow naturally through this path.
-    if video_encoder_config is not None:
-        for field_name, field_value in asdict(video_encoder_config).items():
-            video_info.setdefault(f"video.{field_name}", field_value)
-
-    # Fallback case where no encoder config is provided or the video is not a depth map.
-    video_info.setdefault("video.is_depth_map", False)
-
     return video_info
 
 
-# ─── Depth metadata helpers (reader side) ────────────────────────────
-
-
-_DEPTH_INFO_KEYS: tuple[str, ...] = (
-    "video.depth_min",
-    "video.depth_max",
-    "video.shift",
-    "video.use_log",
-)
-
-
-def seed_depth_feature_info(
-    features: dict[str, dict],
-    depth_encoder_config: "DepthEncoderConfig | None",
-) -> None:
-    """Pre-populate per-feature ``video.<field>`` entries from *depth_encoder_config*.
-
-    ``update_video_info`` only runs after the first episode video is encoded,
-    so without this seeding step ``features[key]["info"]`` carries no
-    quantization range until then. Consumers that read the dataset feature
-    spec mid-recording (e.g. the rerun visualizer pinning the depth colormap
-    to ``video.depth_min`` / ``video.depth_max``) would otherwise see no
-    range during episode 1 and re-normalize per frame.
-
-    Stream-derived values written later by :func:`get_video_info` /
-    ``update_video_info`` win over these seeds (the merge is
-    ``{**existing, **stream_info}``), so callers can safely re-run this on
-    a partially-populated info dict.
-
-    No-op when ``depth_encoder_config`` is ``None`` or no feature is flagged
-    as a depth map.
-    """
-    if depth_encoder_config is None:
-        return
-    encoder_fields = {
-        f"video.{name}": value for name, value in asdict(depth_encoder_config).items()
-    }
-    for ft in features.values():
-        if ft.get("dtype") != "video":
-            continue
-        info = ft.get("info") or {}
-        if not info.get("video.is_depth_map", False):
-            continue
-        # Only fill fields not already set, so explicit user-provided info is preserved.
-        for k, v in encoder_fields.items():
-            info.setdefault(k, v)
-        ft["info"] = info
-
-
 def get_video_pixel_channels(pix_fmt: str) -> int:
     if "gray" in pix_fmt or "depth" in pix_fmt or "monochrome" in pix_fmt:
         return 1

src/lerobot/policies/__init__.py

@@ -12,8 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from lerobot.utils.action_interpolator import ActionInterpolator as ActionInterpolator
-
 from .act.configuration_act import ACTConfig as ACTConfig
 from .diffusion.configuration_diffusion import DiffusionConfig as DiffusionConfig
 from .factory import get_policy_class, make_policy, make_policy_config, make_pre_post_processors
@@ -23,7 +21,10 @@ from .pi0.configuration_pi0 import PI0Config as PI0Config
 from .pi0_fast.configuration_pi0_fast import PI0FastConfig as PI0FastConfig
 from .pi05.configuration_pi05 import PI05Config as PI05Config
 from .pretrained import PreTrainedPolicy as PreTrainedPolicy
+from .rtc import ActionInterpolator as ActionInterpolator
 from .sac.configuration_sac import SACConfig as SACConfig
+from .sac.reward_model.configuration_classifier import RewardClassifierConfig as RewardClassifierConfig
+from .sarm.configuration_sarm import SARMConfig as SARMConfig
 from .smolvla.configuration_smolvla import SmolVLAConfig as SmolVLAConfig
 from .tdmpc.configuration_tdmpc import TDMPCConfig as TDMPCConfig
 from .utils import make_robot_action, prepare_observation_for_inference
@@ -44,7 +45,9 @@ __all__ = [
     "PI0Config",
     "PI0FastConfig",
     "PI05Config",
+    "RewardClassifierConfig",
     "SACConfig",
+    "SARMConfig",
     "SmolVLAConfig",
     "TDMPCConfig",
     "VQBeTConfig",

src/lerobot/policies/act/modeling_act.py

@@ -142,10 +142,9 @@ class ACTPolicy(PreTrainedPolicy):
 
         actions_hat, (mu_hat, log_sigma_x2_hat) = self.model(batch)
 
-        abs_err = F.l1_loss(batch[ACTION], actions_hat, reduction="none")
-        valid_mask = ~batch["action_is_pad"].unsqueeze(-1)
-        num_valid = valid_mask.sum() * abs_err.shape[-1]
-        l1_loss = (abs_err * valid_mask).sum() / num_valid.clamp_min(1)
+        l1_loss = (
+            F.l1_loss(batch[ACTION], actions_hat, reduction="none") * ~batch["action_is_pad"].unsqueeze(-1)
+        ).mean()
 
         loss_dict = {"l1_loss": l1_loss.item()}
         if self.config.use_vae:

src/lerobot/policies/diffusion/modeling_diffusion.py

@@ -380,9 +380,7 @@ class DiffusionModel(nn.Module):
                     f"{self.config.do_mask_loss_for_padding=}."
                 )
             in_episode_bound = ~batch["action_is_pad"]
-            mask = in_episode_bound.unsqueeze(-1)
-            num_valid = mask.sum() * loss.shape[-1]
-            return (loss * mask).sum() / num_valid.clamp_min(1)
+            loss = loss * in_episode_bound.unsqueeze(-1)
 
         return loss.mean()
 

src/lerobot/policies/factory.py

@@ -52,6 +52,8 @@ from .pi0.configuration_pi0 import PI0Config
 from .pi05.configuration_pi05 import PI05Config
 from .pretrained import PreTrainedPolicy
 from .sac.configuration_sac import SACConfig
+from .sac.reward_model.configuration_classifier import RewardClassifierConfig
+from .sarm.configuration_sarm import SARMConfig
 from .smolvla.configuration_smolvla import SmolVLAConfig
 from .tdmpc.configuration_tdmpc import TDMPCConfig
 from .utils import validate_visual_features_consistency
@@ -87,7 +89,7 @@ def get_policy_class(name: str) -> type[PreTrainedPolicy]:
 
     Args:
         name: The name of the policy. Supported names are "tdmpc", "diffusion", "act",
-            "multi_task_dit", "vqbet", "pi0", "pi05", "sac", "smolvla", "wall_x".
+            "multi_task_dit", "vqbet", "pi0", "pi05", "sac", "reward_classifier", "smolvla", "wall_x".
     Returns:
         The policy class corresponding to the given name.
 
@@ -130,10 +132,18 @@ def get_policy_class(name: str) -> type[PreTrainedPolicy]:
         from .sac.modeling_sac import SACPolicy
 
         return SACPolicy
+    elif name == "reward_classifier":
+        from .sac.reward_model.modeling_classifier import Classifier
+
+        return Classifier
     elif name == "smolvla":
         from .smolvla.modeling_smolvla import SmolVLAPolicy
 
         return SmolVLAPolicy
+    elif name == "sarm":
+        from .sarm.modeling_sarm import SARMRewardModel
+
+        return SARMRewardModel
     elif name == "groot":
         from .groot.modeling_groot import GrootPolicy
 
@@ -163,7 +173,7 @@ def make_policy_config(policy_type: str, **kwargs) -> PreTrainedConfig:
     Args:
         policy_type: The type of the policy. Supported types include "tdmpc",
                      "multi_task_dit", "diffusion", "act", "vqbet", "pi0", "pi05", "sac",
-                     "smolvla", "wall_x".
+                     "smolvla", "reward_classifier", "wall_x".
         **kwargs: Keyword arguments to be passed to the configuration class constructor.
 
     Returns:
@@ -190,6 +200,8 @@ def make_policy_config(policy_type: str, **kwargs) -> PreTrainedConfig:
         return SACConfig(**kwargs)
     elif policy_type == "smolvla":
         return SmolVLAConfig(**kwargs)
+    elif policy_type == "reward_classifier":
+        return RewardClassifierConfig(**kwargs)
     elif policy_type == "groot":
         return GrootConfig(**kwargs)
     elif policy_type == "xvla":
@@ -366,6 +378,14 @@ def make_pre_post_processors(
             dataset_stats=kwargs.get("dataset_stats"),
         )
 
+    elif isinstance(policy_cfg, RewardClassifierConfig):
+        from .sac.reward_model.processor_classifier import make_classifier_processor
+
+        processors = make_classifier_processor(
+            config=policy_cfg,
+            dataset_stats=kwargs.get("dataset_stats"),
+        )
+
     elif isinstance(policy_cfg, SmolVLAConfig):
         from .smolvla.processor_smolvla import make_smolvla_pre_post_processors
 
@@ -374,6 +394,14 @@ def make_pre_post_processors(
             dataset_stats=kwargs.get("dataset_stats"),
         )
 
+    elif isinstance(policy_cfg, SARMConfig):
+        from .sarm.processor_sarm import make_sarm_pre_post_processors
+
+        processors = make_sarm_pre_post_processors(
+            config=policy_cfg,
+            dataset_stats=kwargs.get("dataset_stats"),
+            dataset_meta=kwargs.get("dataset_meta"),
+        )
     elif isinstance(policy_cfg, GrootConfig):
         from .groot.processor_groot import make_groot_pre_post_processors
 

src/lerobot/policies/groot/groot_n1.py

@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from dataclasses import dataclass, field
 from pathlib import Path
 from typing import TYPE_CHECKING
 
@@ -173,14 +174,17 @@ N_COLOR_CHANNELS = 3
 
 
 # config
+@dataclass
 class GR00TN15Config(PretrainedConfig):
     model_type = "gr00t_n1_5"
+    backbone_cfg: dict = field(init=False, metadata={"help": "Backbone configuration."})
 
-    backbone_cfg: dict
-    action_head_cfg: dict
-    action_horizon: int
-    action_dim: int
-    compute_dtype: str = "float32"
+    action_head_cfg: dict = field(init=False, metadata={"help": "Action head configuration."})
+
+    action_horizon: int = field(init=False, metadata={"help": "Action horizon."})
+
+    action_dim: int = field(init=False, metadata={"help": "Action dimension."})
+    compute_dtype: str = field(default="float32", metadata={"help": "Compute dtype."})
 
     def __init__(self, **kwargs):
         super().__init__(**kwargs)

src/lerobot/policies/multi_task_dit/modeling_multi_task_dit.py

@@ -688,9 +688,8 @@ class DiffusionObjective(nn.Module):
         loss = F.mse_loss(predicted, target, reduction="none")
 
         if self.do_mask_loss_for_padding and "action_is_pad" in batch:
-            mask = ~batch["action_is_pad"].unsqueeze(-1)
-            num_valid = mask.sum() * loss.shape[-1]
-            return (loss * mask).sum() / num_valid.clamp_min(1)
+            valid_actions = ~batch["action_is_pad"]
+            loss = loss * valid_actions.unsqueeze(-1)
 
         return loss.mean()
 
@@ -753,9 +752,8 @@ class FlowMatchingObjective(nn.Module):
         loss = F.mse_loss(predicted_velocity, target_velocity, reduction="none")
 
         if self.do_mask_loss_for_padding and "action_is_pad" in batch:
-            mask = ~batch["action_is_pad"].unsqueeze(-1)
-            num_valid = mask.sum() * loss.shape[-1]
-            return (loss * mask).sum() / num_valid.clamp_min(1)
+            valid_mask = ~batch["action_is_pad"]
+            loss = loss * valid_mask.unsqueeze(-1)
 
         return loss.mean()