--- pretty_name: HandDiffuse full-view face-mosaicked videos language: - en tags: - hand-motion - bimanual-interaction - mano - video size_categories: - 100K/ metadata.json calibration.json motion/ poses_left.npy poses_right.npy joints_left.npy # original rest joints for selected 51-column motion joints_right.npy output_left.fbx # optional verified same-version source companion output_right.fbx cameras/ primary_/ .mp4 frames.csv full60_/ # optional supplementary original-ID namespace .mp4 frames.csv quality/ boundary_frames.csv # optional recorded boundary screen local_motion_events.json # optional recorded local quality events ``` Actual optional files and camera directories are specified in `metadata.json`. Read those references rather than guessing filenames, pairing sorted directories, or assuming camera IDs are contiguous. A camera's video ID and calibration parameter ID are separate fields. A supplementary namespace may reuse a numeric ID without referring to the primary camera with that ID. The package provides processed videos and preserves selected motion arrays. Excluded or unavailable rows are represented by metadata and masks; they are not silently removed, interpolated, or renumbered. ## Read an episode Use Python 3.10 or later. NumPy is required for numeric motion loading; the metadata and CSV reader uses the standard library. Place `handdiffuse_reader.py` on the Python import path. ```python from handdiffuse_reader import Episode # Run from the package root containing episodes/. episode = Episode(".", "tutting_19") left = episode.load_motion("left") # read-only memory map, [motion_rows, 51 or 61] right = episode.load_motion("right") camera_uid = next(iter(episode.cameras)) camera = episode.cameras[camera_uid] original_parameters = episode.calibration(camera_uid) video_path = episode.path(camera["video_file"]) for row in episode.iter_frame_map(camera_uid): if not row.available: # This motion row has no source frame in this particular camera. continue if not row.passes_recorded_screens: # Application choice: skip rows covered by recorded conservative screens. continue video_index = row.video_index source_presentation_time = row.video_pts * row.video_time_base # Check row.has_approximate_timing when exact motion/video correspondence matters. # Approximate rows expose row.alternative_video_index and its source PTS. motion_left = left[row.motion_index] motion_right = right[row.motion_index] # Decode the recorded source video index with a decoder of your choice. ``` `passes_recorded_screens` combines source availability with the recorded boundary and local motion screens. It does not certify unreviewed frames, anatomical accuracy, hidden fingers, physical contact, or freedom from collision. Flags are retained on each yielded row. Boundary and local exclusions are combined as an index union; overlapping reasons do not remove two rows. Iterate each frame map to exhaustion to check its complete row count and agreement with the metadata's missing-source indices. Array shape/dtype checks and annotation bindings are checked on reading. The reference reader does not calculate file-content hashes, decode video content, reconstruct MANO meshes, or select a different motion version. ## Motion parameters All slices below use Python's zero-based, end-exclusive convention. | Columns | Meaning | | --- | --- | | `0:3` | Saved source root/wrist position | | `3:51` | Sixteen axis-angle rotations, in radians: root orientation followed by fifteen local joint rotations in source MANO order | | `51:61` | Ten stored shape coefficients, present only in 61-column arrays | The saved rotation vectors represent the full pose rather than PCA coefficients. For the documented 61-column reconstruction, use the saved pose and beta without adding another mean-pose rotation. Given raw posed model vertices and joints, bind the posed wrist to the stored position: ```python vertices_source = vertices_raw - joints_raw[0] + motion_row[0:3] joints_source = joints_raw - joints_raw[0] + motion_row[0:3] ``` Retain each episode's documented reconstruction convention. Physical length units and absolute world-axis semantics have not been independently established for every capture family; retain source coordinates and calibration translation values together instead of applying an assumed scale or recentering operation. A 51-column file contains no beta coefficients. Do not append zeros or infer a shape silently. Use its supplied original rest joints for forward kinematics, or use the optional original same-version FBX geometry and skinning. Matching FBX animation keys do not establish surface equality with an arbitrary MANO renderer or pose-corrective implementation. MANO model weights are not included in the planned assets. Obtain any required model through its original provider under the applicable terms. This documentation does not grant a model license. ## Camera parameters `calibration.json` stores original values grouped by parameter namespace. `metadata.json` binds each listed camera to a namespace and original parameter ID. Calibration may contain additional original entries; an entry's presence does not by itself mean that its video or frame correspondence has been accepted. For an original `RT` entry reshaped to 3 by 4, the convention is: ```python X_camera = RT[:, :3] @ X_source + RT[:, 3] homogeneous_pixel = K @ X_camera pixel = homogeneous_pixel[:2] / homogeneous_pixel[2] ``` Keep the original image size and distortion values, and follow the recorded image convention when applying distortion. K and RT are stored as flat numeric arrays in the current schema. Camera values and original IDs are retained; no newly fitted camera parameters are substituted by the reference reader. ## Frame correspondence Each camera has its own `frames.csv` with: | Field | Meaning | | --- | --- | | `motion_frame_index` | Row in both selected hand arrays, starting at zero | | `video_frame_index` | Decoded source-video frame index, starting at zero; empty when unavailable | | `video_pts` | Original decoded presentation timestamp; empty when unavailable | | `video_time_base` | Rational units per timestamp tick | | `video_timestamp_seconds` | Recorded timestamp in seconds | | `source_frame_available` | Optional explicit `0`/`1` availability flag | | `alignment_certainty` | Present on accepted approximate maps: `APPROXIMATE_ADJACENT_FRAME_SELECTION` | | `alternative_video_frame_index` | Adjacent candidate source index on approximate maps | | `alternative_video_pts` | Decoded PTS of the alternative, using the same time base | | `alternative_video_timestamp_seconds` | Alternative decoded timestamp in seconds | Do not infer a universal motion FPS, a fixed downsampling factor, or capture timing from the FBX export clock. Empty source indices and timestamps remain explicit. A repeated or uneven source sampling interval is not corrected by inventing frames. The existence of a row mapping does not establish physical subframe exposure synchronization. Eight Ninja episodes (8, 9, 13, 14, 17, 19, 22, 27) use owner-delegated approximate alignment. Each has one fixed default offset shared by its six cameras, plus an explicit adjacent alternative. The original extraction indices remain unrecovered; these candidates are not a proven hard timing-error bound. Camera metadata records `alignment_certainty`, both offsets, and `exact_extraction_index_recovered: false`. The reader exposes this on every `Frame`; `passes_recorded_screens` concerns motion-quality screens and does not remove or certify approximate timing. Applications requiring uniquely supported motion-to-video indices should filter `row.has_approximate_timing`. Original camera parameters and motion values remain unchanged. ## Version and quality information The selected pair is described by the episode metadata. Selection can favor an older motion version: filename recency and smoothness alone do not establish correspondence or hand quality. Quality annotations are bound to the selected motion hashes; do not reuse them with a different version. Some episodes have conservative boundary or local correspondence screens. An interval can include unshown or uncertain transitions; it does not mean every included row is individually confirmed erroneous. Preserve event descriptions and their scope when reporting downstream filtering. Remaining curation limitations include missing multi-view source groups, unresolved camera/time correspondences, unknown provenance for additional motion candidates, and sparse rather than exhaustive geometry review. The draft's candidate and camera coverage counts are not a complete-release or whole-episode quality claim. ## Citation and licensing A dataset license and formal citation have not been supplied. Public availability does not by itself grant an open license. No license is invented by this preparation. Keep source identities and machine-specific curation paths out of the public package.