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

src/lerobot/configs/__init__.py

@@ -31,6 +31,12 @@ from .types import (
     PolicyFeature,
     RTCAttentionSchedule,
 )
+from .video import (
+    VALID_VIDEO_CODECS,
+    VIDEO_ENCODER_INFO_KEYS,
+    VideoEncoderConfig,
+    camera_encoder_defaults,
+)
 
 __all__ = [
     # Types
@@ -46,4 +52,10 @@ __all__ = [
     "PeftConfig",
     "PreTrainedConfig",
     "WandBConfig",
+    "VideoEncoderConfig",
+    # Defaults
+    "camera_encoder_defaults",
+    # Constants
+    "VALID_VIDEO_CODECS",
+    "VIDEO_ENCODER_INFO_KEYS",
 ]

src/lerobot/configs/dataset.py

@@ -18,7 +18,7 @@ from dataclasses import dataclass, field
 from datetime import datetime
 from pathlib import Path
 
-from lerobot.datasets.video_utils import VideoEncoderConfig, camera_encoder_defaults
+from .video import VideoEncoderConfig, camera_encoder_defaults
 
 
 @dataclass

src/lerobot/configs/video.py

@@ -0,0 +1,201 @@
+# 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.
+# Note: We subclass str so that serialization is straightforward
+# https://stackoverflow.com/questions/24481852/serialising-an-enum-member-to-json
+
+"""Video encoder configurations."""
+
+import logging
+from dataclasses import dataclass, field
+from typing import TYPE_CHECKING, Any
+
+from lerobot.utils.import_utils import _av_available, require_package
+
+if TYPE_CHECKING or _av_available:
+    from lerobot.datasets.pyav_utils import check_video_encoder_config_pyav, detect_available_encoders_pyav
+
+logger = logging.getLogger(__name__)
+
+# List of hardware encoders to probe for auto-selection. Availability depends on the platform and the chosen video backend.
+# Determines the order of preference for auto-selection when vcodec="auto" is used.
+HW_VIDEO_CODECS = [
+    "h264_videotoolbox",  # macOS
+    "hevc_videotoolbox",  # macOS
+    "h264_nvenc",  # NVIDIA GPU
+    "hevc_nvenc",  # NVIDIA GPU
+    "h264_vaapi",  # Linux Intel/AMD
+    "h264_qsv",  # Intel Quick Sync
+]
+VALID_VIDEO_CODECS: frozenset[str] = frozenset({"h264", "hevc", "libsvtav1", "auto", *HW_VIDEO_CODECS})
+
+LIBSVTAV1_DEFAULT_PRESET: int = 12
+
+# Keys persisted under ``features[*]["info"]`` as ``video.<name>`` (from :class:`VideoEncoderConfig`).
+# ``vcodec``` and ``pix_fmt`` are derived from the video stream directly.
+VIDEO_ENCODER_INFO_FIELD_NAMES: frozenset[str] = frozenset(
+    {"g", "crf", "preset", "fast_decode", "extra_options", "video_backend"}
+)
+VIDEO_ENCODER_INFO_KEYS: frozenset[str] = frozenset(
+    f"video.{name}" for name in VIDEO_ENCODER_INFO_FIELD_NAMES
+)
+
+
+@dataclass
+class VideoEncoderConfig:
+    """Video encoder configuration.
+
+    Attributes:
+        vcodec: Video 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 to be used for encoding. Only ``"pyav"``
+            is currently supported.
+        extra_options: Free-form dictionary of additional video encoder options
+            (e.g. ``{"tune": "film", "profile:v": "high", "bf": 2}``).
+    """
+
+    vcodec: str = "libsvtav1"  # TODO(CarolinePascal): rename to codec ?
+    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)
+
+    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]:
+        """Return the subset of available encoders based on the specified video backend.
+
+        Args:
+            encoders: List of encoder names to detect. If a string, it is converted to a list.
+        Returns:
+            List of available encoder names. If the video backend is not "pyav", returns an empty list.
+        """
+        if self.video_backend == "pyav":
+            require_package("av", extra="dataset")
+            return detect_available_encoders_pyav(encoders)
+        return []
+
+    def validate(self) -> None:
+        """Validate the video encoder configuration."""
+        if self.video_backend == "pyav":
+            require_package("av", extra="dataset")
+            check_video_encoder_config_pyav(self)
+
+    def resolve_vcodec(self) -> None:
+        """Check ``vcodec`` and, when it is ``"auto"``, pick a concrete encoder.
+
+        For ``"auto"``, the first hardware encoder in the preference list that is available is chosen; if none are available, ``libsvtav1`` is used. If the
+        resolved codec (explicit or after auto-selection) is not available, raises ``ValueError``.
+        """
+        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_VIDEO_CODECS)
+            for encoder in HW_VIDEO_CODECS:
+                if encoder in available:
+                    logger.info(f"Auto-selected video codec: {encoder}")
+                    self.vcodec = encoder
+                    return
+            logger.warning("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}")
+            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, Any]:
+        """Translate the tuning fields to codec-specific 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)
+        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
+
+
+def camera_encoder_defaults() -> VideoEncoderConfig:
+    """Return a :class:`VideoEncoderConfig` with RGB-camera defaults."""
+    return VideoEncoderConfig()

src/lerobot/datasets/pyav_utils.py

@@ -23,12 +23,11 @@ from __future__ import annotations
 
 import functools
 import logging
-from typing import TYPE_CHECKING, Any
+from typing import Any
 
 import av
 
-if TYPE_CHECKING:
+from lerobot.configs.video import VideoEncoderConfig
-    from .video_utils import VideoEncoderConfig
 
 logger = logging.getLogger(__name__)
 
@@ -167,7 +166,7 @@ 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`
+    encoder option from :meth:`~lerobot.configs.video.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.
 

src/lerobot/datasets/video_utils.py

@@ -37,177 +37,14 @@ import torchvision
 from datasets.features.features import register_feature
 from PIL import Image
 
+from lerobot.configs.video import (
+    VideoEncoderConfig,
+    camera_encoder_defaults,
+)
 from lerobot.utils.import_utils import get_safe_default_video_backend
 
-from .pyav_utils import (
-    check_video_encoder_config_pyav,
-    detect_available_encoders_pyav,
-)
-
 logger = logging.getLogger(__name__)
 
-# List of hardware encoders to probe for auto-selection. Availability depends on the platform and FFmpeg build.
-# Determines the order of preference for auto-selection when vcodec="auto" is used.
-HW_VIDEO_CODECS = [
-    "h264_videotoolbox",  # macOS
-    "hevc_videotoolbox",  # macOS
-    "h264_nvenc",  # NVIDIA GPU
-    "hevc_nvenc",  # NVIDIA GPU
-    "h264_vaapi",  # Linux Intel/AMD
-    "h264_qsv",  # Intel Quick Sync
-]
-
-VALID_VIDEO_CODECS = {"h264", "hevc", "libsvtav1", "auto"} | set(HW_VIDEO_CODECS)
-
-LIBSVTAV1_DEFAULT_PRESET: int = 12
-
-
-@dataclass
-class VideoEncoderConfig:
-    """Video encoder configuration.
-
-    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}``).
-    """
-
-    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)
-
-    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:
-        """Check ``vcodec`` and, when it is ``"auto"``, pick a concrete encoder.
-
-        For ``"auto"``, the first hardware encoder in the preference list that FFmpeg
-        exposes is chosen; if none are available, ``libsvtav1`` is used. If the
-        resolved codec (explicit or after auto-selection) is not present in the
-        local FFmpeg build, raises ``ValueError``.
-        """
-        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_VIDEO_CODECS)
-            for encoder in HW_VIDEO_CODECS:
-                if encoder in available:
-                    logger.info(f"Auto-selected video codec: {encoder}")
-                    self.vcodec = encoder
-                    return
-            logger.warning("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}")
-            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, Any]:
-        """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)
-        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
-
-
-def camera_encoder_defaults() -> VideoEncoderConfig:
-    """Return a :class:`VideoEncoderConfig` with RGB-camera defaults."""
-    return VideoEncoderConfig()
-
 
 def decode_video_frames(
     video_path: Path | str,

src/lerobot/utils/import_utils.py

@@ -128,6 +128,9 @@ _hidapi_available = is_package_available("hidapi", import_name="hid")
 _pandas_available = is_package_available("pandas")
 _faker_available = is_package_available("faker")
 
+# Video encoding / decoding
+_av_available = is_package_available("av")
+
 # Misc
 _pynput_available = is_package_available("pynput")
 _pygame_available = is_package_available("pygame")

tests/datasets/test_datasets.py

@@ -31,6 +31,7 @@ from torchvision.transforms import v2
 
 from lerobot.configs.default import DatasetConfig
 from lerobot.configs.train import TrainPipelineConfig
+from lerobot.configs.video import VALID_VIDEO_CODECS, VideoEncoderConfig
 from lerobot.datasets import make_dataset
 from lerobot.datasets.feature_utils import get_hf_features_from_features
 from lerobot.datasets.image_writer import image_array_to_pil_image
@@ -43,7 +44,6 @@ from lerobot.datasets.utils import (
     DEFAULT_VIDEO_FILE_SIZE_IN_MB,
     create_branch,
 )
-from lerobot.datasets.video_utils import VALID_VIDEO_CODECS, VideoEncoderConfig
 from lerobot.envs.factory import make_env_config
 from lerobot.policies.factory import make_policy_config
 from lerobot.robots import make_robot_from_config

tests/datasets/test_video_encoding.py

@@ -26,13 +26,12 @@ pytest.importorskip("av", reason="av is required (install lerobot[dataset])")
 
 import av  # noqa: E402
 
+from lerobot.configs.video import VALID_VIDEO_CODECS, VideoEncoderConfig
 from lerobot.datasets.image_writer import write_image
 from lerobot.datasets.lerobot_dataset import LeRobotDataset
 from lerobot.datasets.pyav_utils import get_codec
 from lerobot.datasets.utils import INFO_PATH
 from lerobot.datasets.video_utils import (
-    VALID_VIDEO_CODECS,
-    VideoEncoderConfig,
     concatenate_video_files,
     encode_video_frames,
     get_video_info,