feat(encoding parameters): adding support for user provided video encoding parameters (#3455)

* chore(video backend): renaming codec into video_backend in get_safe_default_video_backend()

* feat(pyav utils): adding suport for PyAV encoding parameters validation

* feat(VideoEncoderConfig): creating a VideoEncoderConfig to encapsulate encoding parameters

* feat(VideoEncoderConfig): propagating the VideoEncoderConfig in the codebase

* chore(docs): updating the docs

* feat(metadata): adding encoding parameters in dataset metadata

* fix(concatenation compatibility): adding compatibility check when concatenating video files

* feat(VideoEncoderConfig init): making VideoEncoderConfig more robust and adaptable to multiple backends

* feat(pyav checks): making pyav parameters checks more robust

* chore(duplicate): removing duplicate get_codec_options definition

* test(existing): adapting existing tests

* test(new): adding new tests for encoding related features

* chore(format): fixing formatting issues

* chore(PyAV): cleaning up PyAV utils and encoding parameters checks to stick to the minimun required tooling.

* chore(format): formatting code

* chore(doctrings): updating docstrings

* fix(camera_encoder_config): Removing camera_encoder_config from LeRobotDataset, as it's only required in LeRobotDatasetWriter.

* feat(default values): applying a consistent naming convention for default RGB cameras video encoder parameters

* fix(rollout): propagating VideoEncoderConfig to the latest recording modes

* chore(format): formatting code, fixing error messages and variable names

* fix(arguments order): reverting changes in arguments order in StreamingVideoEncoder

* chore(relative imports): switching to relative local imports within lerobot.datasets

* test(artifacts): cleaning up artifacts for the video encoding tests

* chore(docs): updating docs

* chore(fromat): formatting code

* fix(imports): refactoring the file architecture to avoid circular imports. VideoEncoderConfig is now defined in lerobot.configs and lazily imports av at runtime.

* fix(typos): fixing typos and small mistakes

* test(factories): updating factories

* feat(aggregate): updating dataset aggregation procedure. Encoding tuning paramters (crf, g,...) are ignored for validation and changed to None in the aggregated dataset if incompatible.

* docs(typos): fixing typos

* fix(deletion): reverting unwanted deletion

* fix(typos): fixing multiple typos

* feat(codec options): passing codec options to lerobot_edit_dataset episode deletion tool

* typo(typo): typo

* fix(typos): fixing remaining typos

* chore(rename): renaming camera_encoder_config to camera_encoder

* docs(clean): cleaning and formating docs

* docs(dataset): addind details about datasets

* chore(format): formatting code

* docs(warning): adding warning regarding encoding parameters modification

* fix(re-encoding): removing inconsistent re-encoding option in lerobot_edit_dataset

* typos(typos): typos

* chore(format): resolving prettier issues

* fix(h264_nvenc): fixing crf handling for h264_nvenc

* docs(clean): removing too technical parts of the docs

* fix(imports): fixing imports at the __init__ level

* fix(imports): fixing not very pretty imports in video config file

tests/datasets/test_dataset_writer.py

@@ -25,6 +25,7 @@ from PIL import Image
 
 pytest.importorskip("datasets", reason="datasets is required (install lerobot[dataset])")
 
+from lerobot.configs import VideoEncoderConfig
 from lerobot.datasets.dataset_writer import _encode_video_worker
 from lerobot.datasets.lerobot_dataset import LeRobotDataset
 from lerobot.datasets.utils import DEFAULT_IMAGE_PATH
@@ -52,8 +53,8 @@ def _make_frame(features: dict, task: str = "Dummy task") -> dict:
 # ── Existing encode_video_worker tests ───────────────────────────────
 
 
-def test_encode_video_worker_forwards_vcodec(tmp_path):
-    """_encode_video_worker correctly forwards the vcodec parameter."""
+def test_encode_video_worker_forwards_camera_encoder(tmp_path):
+    """_encode_video_worker forwards camera_encoder to encode_video_frames."""
     video_key = "observation.images.laptop"
     fpath = DEFAULT_IMAGE_PATH.format(image_key=video_key, episode_index=0, frame_index=0)
     img_dir = tmp_path / Path(fpath).parent
@@ -68,13 +69,21 @@ def test_encode_video_worker_forwards_vcodec(tmp_path):
         Path(video_path).touch()
 
     with patch("lerobot.datasets.dataset_writer.encode_video_frames", side_effect=mock_encode):
-        _encode_video_worker(video_key, 0, tmp_path, fps=30, vcodec="h264")
+        _encode_video_worker(
+            video_key,
+            0,
+            tmp_path,
+            fps=30,
+            camera_encoder=VideoEncoderConfig(vcodec="h264", preset=None),
+            encoder_threads=4,
+        )
 
-    assert captured_kwargs["vcodec"] == "h264"
+    assert captured_kwargs["camera_encoder"].vcodec == "h264"
+    assert captured_kwargs["encoder_threads"] == 4
 
 
-def test_encode_video_worker_default_vcodec(tmp_path):
-    """_encode_video_worker uses libsvtav1 as the default codec."""
+def test_encode_video_worker_default_camera_encoder(tmp_path):
+    """_encode_video_worker passes None camera_encoder which encode_video_frames defaults."""
     video_key = "observation.images.laptop"
     fpath = DEFAULT_IMAGE_PATH.format(image_key=video_key, episode_index=0, frame_index=0)
     img_dir = tmp_path / Path(fpath).parent
@@ -91,7 +100,8 @@ def test_encode_video_worker_default_vcodec(tmp_path):
     with patch("lerobot.datasets.dataset_writer.encode_video_frames", side_effect=mock_encode):
         _encode_video_worker(video_key, 0, tmp_path, fps=30)
 
-    assert captured_kwargs["vcodec"] == "libsvtav1"
+    assert captured_kwargs["camera_encoder"] is None
+    assert captured_kwargs["encoder_threads"] is None
 
 
 # ── add_frame contracts ──────────────────────────────────────────────