Files
lerobot-clone/src/lerobot/datasets/multi_dataset.py
2026-03-15 23:07:52 -07:00

211 lines
8.2 KiB
Python

#!/usr/bin/env python
# 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.
import logging
from collections.abc import Callable
from pathlib import Path
import datasets
import torch
import torch.utils
from lerobot.datasets.compute_stats import aggregate_stats
from lerobot.datasets.lerobot_dataset import LeRobotDataset
from lerobot.datasets.video_utils import VideoFrame
from lerobot.utils.constants import HF_LEROBOT_HOME
logger = logging.getLogger(__name__)
class MultiLeRobotDataset(torch.utils.data.Dataset):
"""A dataset consisting of multiple underlying `LeRobotDataset`s.
The underlying `LeRobotDataset`s are effectively concatenated, and this class adopts much of the API
structure of `LeRobotDataset`.
"""
def __init__(
self,
repo_ids: list[str],
root: str | Path | None = None,
episodes: dict | None = None,
image_transforms: Callable | None = None,
delta_timestamps: dict[str, list[float]] | None = None,
tolerances_s: dict | None = None,
download_videos: bool = True,
video_backend: str | None = None,
):
super().__init__()
self.repo_ids = repo_ids
self.root = Path(root) if root else HF_LEROBOT_HOME
self.tolerances_s = tolerances_s if tolerances_s else dict.fromkeys(repo_ids, 0.0001)
# Construct the underlying datasets passing everything but `transform` and `delta_timestamps` which
# are handled by this class.
self._datasets = [
LeRobotDataset(
repo_id,
root=self.root / repo_id,
episodes=episodes[repo_id] if episodes else None,
image_transforms=image_transforms,
delta_timestamps=delta_timestamps,
tolerance_s=self.tolerances_s[repo_id],
download_videos=download_videos,
video_backend=video_backend,
)
for repo_id in repo_ids
]
# Disable any data keys that are not common across all of the datasets. Note: we may relax this
# restriction in future iterations of this class. For now, this is necessary at least for being able
# to use PyTorch's default DataLoader collate function.
self.disabled_features = set()
intersection_features = set(self._datasets[0].features)
for ds in self._datasets:
intersection_features.intersection_update(ds.features)
if len(intersection_features) == 0:
raise RuntimeError(
"Multiple datasets were provided but they had no keys common to all of them. "
"The multi-dataset functionality currently only keeps common keys."
)
for repo_id, ds in zip(self.repo_ids, self._datasets, strict=True):
extra_keys = set(ds.features).difference(intersection_features)
if extra_keys:
logger.warning(
f"keys {extra_keys} of {repo_id} were disabled as they are not contained in all the "
"other datasets."
)
self.disabled_features.update(extra_keys)
self.image_transforms = image_transforms
self.delta_timestamps = delta_timestamps
# TODO(rcadene, aliberts): We should not perform this aggregation for datasets
# with multiple robots of different ranges. Instead we should have one normalization
# per robot.
self.stats = aggregate_stats([dataset.meta.stats for dataset in self._datasets])
@property
def repo_id_to_index(self):
"""Return a mapping from dataset repo_id to a dataset index automatically created by this class.
This index is incorporated as a data key in the dictionary returned by `__getitem__`.
"""
return {repo_id: i for i, repo_id in enumerate(self.repo_ids)}
@property
def fps(self) -> int:
"""Frames per second used during data collection.
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"]
@property
def video(self) -> bool:
"""Returns True if this dataset loads video frames from mp4 files.
Returns False if it only loads images from png files.
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.get("video", False)
@property
def features(self) -> datasets.Features:
features = {}
for dataset in self._datasets:
features.update({k: v for k, v in dataset.hf_features.items() if k not in self.disabled_features})
return features
@property
def camera_keys(self) -> list[str]:
"""Keys to access image and video stream from cameras."""
keys = []
for key, feats in self.features.items():
if isinstance(feats, (datasets.Image | VideoFrame)):
keys.append(key)
return keys
@property
def video_frame_keys(self) -> list[str]:
"""Keys to access video frames that requires to be decoded into images.
Note: It is empty if the dataset contains images only,
or equal to `self.cameras` if the dataset contains videos only,
or can even be a subset of `self.cameras` in a case of a mixed image/video dataset.
"""
video_frame_keys = []
for key, feats in self.features.items():
if isinstance(feats, VideoFrame):
video_frame_keys.append(key)
return video_frame_keys
@property
def num_frames(self) -> int:
"""Number of samples/frames."""
return sum(d.num_frames for d in self._datasets)
@property
def num_episodes(self) -> int:
"""Number of episodes."""
return sum(d.num_episodes for d in self._datasets)
@property
def tolerance_s(self) -> float:
"""Tolerance in seconds used to discard loaded frames when their timestamps
are not close enough from the requested frames. It is only used when `delta_timestamps`
is provided or when loading video frames from mp4 files.
"""
# 1e-4 to account for possible numerical error
return 1 / self.fps - 1e-4
def __len__(self):
return self.num_frames
def __getitem__(self, idx: int) -> dict[str, torch.Tensor]:
if idx >= len(self):
raise IndexError(f"Index {idx} out of bounds.")
# Determine which dataset to get an item from based on the index.
start_idx = 0
dataset_idx = 0
for dataset in self._datasets:
if idx >= start_idx + dataset.num_frames:
start_idx += dataset.num_frames
dataset_idx += 1
continue
break
else:
raise AssertionError("We expect the loop to break out as long as the index is within bounds.")
item = self._datasets[dataset_idx][idx - start_idx]
item["dataset_index"] = torch.tensor(dataset_idx)
for data_key in self.disabled_features:
if data_key in item:
del item[data_key]
return item
def __repr__(self):
return (
f"{self.__class__.__name__}(\n"
f" Repository IDs: '{self.repo_ids}',\n"
f" Number of Samples: {self.num_frames},\n"
f" Number of Episodes: {self.num_episodes},\n"
f" Type: {'video (.mp4)' if self.video else 'image (.png)'},\n"
f" Recorded Frames per Second: {self.fps},\n"
f" Camera Keys: {self.camera_keys},\n"
f" Video Frame Keys: {self.video_frame_keys if self.video else 'N/A'},\n"
f" Transformations: {self.image_transforms},\n"
f")"
)