Add verified single-record download guidance

Add an exact CC BY-NC 4.0 root license notice, a helper that pins a revision and separately verifies Xet identity, byte size, and local SHA-256, and README guidance clarifying that RELEASE_MANIFEST.json is the historical v0.2.0 candidate rather than a current video-payload manifest. Local validation passed for all 490 metadata rows; a 28,526,284-byte record passed an end-to-end download and SHA-256 check.

LICENSE

@@ -0,0 +1,20 @@
+Time-Lapse Artifacts
+Copyright (c) 2026 Tim Maxwell
+
+Except where otherwise noted, this dataset is licensed under the Creative
+Commons Attribution-NonCommercial 4.0 International license (CC BY-NC 4.0):
+
+https://creativecommons.org/licenses/by-nc/4.0/
+
+Legal code:
+
+https://creativecommons.org/licenses/by-nc/4.0/legalcode
+
+The license applies only to material for which the licensor holds the
+necessary rights. It does not independently grant rights in incidental
+third-party content that may appear on screens, in references, or in captured
+audio. Users remain responsible for reviewing those rights and the terms of
+their downstream use.
+
+See README.md for the dataset's rights, privacy, audio, and attribution
+guidance.

README.md

@@ -1,681 +1,716 @@
----
-license: cc-by-nc-4.0
-pretty_name: Time-Lapse Artifacts
-annotations_creators:
-- expert-generated
-source_datasets:
-- original
-size_categories:
-- n<1K
-task_categories:
-- video-classification
-- feature-extraction
-tags:
-- drawing
-- longitudinal-study
-- traditional-art
-- provenance
-- single-subject
-- video
-- computer-vision
-- time-lapse
-- human-motion
-dataset_info:
-- config_name: canonical
-  features:
-  - name: video
-    dtype: video
-  - name: record_id
-    dtype: large_string
-  - name: collection_tier
-    dtype: large_string
-  - name: is_canonical
-    dtype: bool
-  - name: acquisition_protocol_version
-    dtype: large_string
-  - name: date
-    dtype: large_string
-  - name: time
-    dtype: large_string
-  - name: tool
-    dtype: large_string
-  - name: medium
-    dtype: large_string
-  - name: support
-    dtype: large_string
-  - name: dimensions
-    dtype: large_string
-  - name: duration_seconds
-    dtype: float64
-  - name: width_px
-    dtype: int64
-  - name: height_px
-    dtype: int64
-  - name: orientation
-    dtype: large_string
-  - name: encoded_frame_rate
-    dtype: float64
-  - name: video_codec
-    dtype: large_string
-  - name: pixel_format
-    dtype: large_string
-  - name: container
-    dtype: large_string
-  - name: has_audio
-    dtype: bool
-  - name: hub_xet_hash
-    dtype: large_string
-  - name: original_filename
-    dtype: large_string
-  - name: provenance_status
-    dtype: large_string
-  - name: legacy_provenance_path
-    dtype: large_string
-  - name: legacy_related_references
-    dtype: large_string
-  - name: evidence_method
-    dtype: large_string
-  - name: provenance_reference_duration_delta_seconds
-    dtype: float64
-  - name: size_bytes
-    dtype: int64
-  - name: notes
-    dtype: large_string
-  splits:
-  - name: archive
-    num_examples: 362
-- config_name: pre_standard
-  features:
-  - name: video
-    dtype: video
-  - name: record_id
-    dtype: large_string
-  - name: collection_tier
-    dtype: large_string
-  - name: is_canonical
-    dtype: bool
-  - name: acquisition_protocol_version
-    dtype: large_string
-  - name: date
-    dtype: large_string
-  - name: time
-    dtype: large_string
-  - name: tool
-    dtype: large_string
-  - name: medium
-    dtype: large_string
-  - name: support
-    dtype: large_string
-  - name: dimensions
-    dtype: large_string
-  - name: duration_seconds
-    dtype: float64
-  - name: width_px
-    dtype: int64
-  - name: height_px
-    dtype: int64
-  - name: orientation
-    dtype: large_string
-  - name: encoded_frame_rate
-    dtype: float64
-  - name: video_codec
-    dtype: large_string
-  - name: pixel_format
-    dtype: large_string
-  - name: container
-    dtype: large_string
-  - name: has_audio
-    dtype: bool
-  - name: hub_xet_hash
-    dtype: large_string
-  - name: original_filename
-    dtype: large_string
-  - name: provenance_status
-    dtype: large_string
-  - name: legacy_provenance_path
-    dtype: large_string
-  - name: legacy_related_references
-    dtype: large_string
-  - name: evidence_method
-    dtype: large_string
-  - name: provenance_reference_duration_delta_seconds
-    dtype: float64
-  - name: size_bytes
-    dtype: int64
-  - name: notes
-    dtype: large_string
-  splits:
-  - name: archive
-    num_examples: 128
-configs:
-- config_name: canonical
-  default: true
-  features:
-  - name: video
-    dtype: video
-  - name: record_id
-    dtype: large_string
-  - name: collection_tier
-    dtype: large_string
-  - name: is_canonical
-    dtype: bool
-  - name: acquisition_protocol_version
-    dtype: large_string
-  - name: date
-    dtype: large_string
-  - name: time
-    dtype: large_string
-  - name: tool
-    dtype: large_string
-  - name: medium
-    dtype: large_string
-  - name: support
-    dtype: large_string
-  - name: dimensions
-    dtype: large_string
-  - name: duration_seconds
-    dtype: float64
-  - name: width_px
-    dtype: int64
-  - name: height_px
-    dtype: int64
-  - name: orientation
-    dtype: large_string
-  - name: encoded_frame_rate
-    dtype: float64
-  - name: video_codec
-    dtype: large_string
-  - name: pixel_format
-    dtype: large_string
-  - name: container
-    dtype: large_string
-  - name: has_audio
-    dtype: bool
-  - name: hub_xet_hash
-    dtype: large_string
-  - name: original_filename
-    dtype: large_string
-  - name: provenance_status
-    dtype: large_string
-  - name: legacy_provenance_path
-    dtype: large_string
-  - name: legacy_related_references
-    dtype: large_string
-  - name: evidence_method
-    dtype: large_string
-  - name: provenance_reference_duration_delta_seconds
-    dtype: float64
-  - name: size_bytes
-    dtype: int64
-  - name: notes
-    dtype: large_string
-  data_files:
-  - split: archive
-    path:
-    - metadata.csv
-    - Standard_Time_Lapses/*.mp4
-- config_name: pre_standard
-  features:
-  - name: video
-    dtype: video
-  - name: record_id
-    dtype: large_string
-  - name: collection_tier
-    dtype: large_string
-  - name: is_canonical
-    dtype: bool
-  - name: acquisition_protocol_version
-    dtype: large_string
-  - name: date
-    dtype: large_string
-  - name: time
-    dtype: large_string
-  - name: tool
-    dtype: large_string
-  - name: medium
-    dtype: large_string
-  - name: support
-    dtype: large_string
-  - name: dimensions
-    dtype: large_string
-  - name: duration_seconds
-    dtype: float64
-  - name: width_px
-    dtype: int64
-  - name: height_px
-    dtype: int64
-  - name: orientation
-    dtype: large_string
-  - name: encoded_frame_rate
-    dtype: float64
-  - name: video_codec
-    dtype: large_string
-  - name: pixel_format
-    dtype: large_string
-  - name: container
-    dtype: large_string
-  - name: has_audio
-    dtype: bool
-  - name: hub_xet_hash
-    dtype: large_string
-  - name: original_filename
-    dtype: large_string
-  - name: provenance_status
-    dtype: large_string
-  - name: legacy_provenance_path
-    dtype: large_string
-  - name: legacy_related_references
-    dtype: large_string
-  - name: evidence_method
-    dtype: large_string
-  - name: provenance_reference_duration_delta_seconds
-    dtype: float64
-  - name: size_bytes
-    dtype: int64
-  - name: notes
-    dtype: large_string
-  data_files:
-  - split: archive
-    path:
-    - Pre_Standard_Time_Lapses/metadata.csv
-    - Pre_Standard_Time_Lapses/*.mp4
----
-
-# time-lapse-artifacts
-
-490 time-lapse recordings of one artist's traditional drawing practice across
-nearly two years (September 2024–August 22, 2026), with standardized acquisition
-since July 13, 2025. Across approximately 1.98 TB of video, the archive follows
-the same artist working in physical media—including pencil, ballpoint pen,
-fountain pen, brush, graphite, and ink—on fixed-format paper and illustration board.
-The release combines 362 canonical Standard videos and 128 earlier
-Pre-Standard recordings. Every published video has a persistent record ID,
-content hash, byte size, and encoded-stream metadata; historical session and
-provenance fields remain less complete in the Pre-Standard tier.
-
-In this dataset, provenance refers to the documented relationship between a
-physical drawing and its time-lapse record, rather than to histories of
-ownership or sale.
-
-An earlier 2012–2016 archive of more than 8 TB also exists, consisting
-primarily of uploaded 1080p drawing videos, with some livestream-derived
-material. It is not yet published in this dataset and is excluded from the
-current 490-record, 1.98-TB release totals. This is an active construction
-release.
-
-## Snapshot and Coverage
-
-These counts describe the current `main` branch. The immutable `v0.3.0` tag
-contains 467 rows: 338 Standard and 129 Pre-Standard. A later curator-verified
-provenance correction promoted one distinct Standard recording from the
-noncanonical unresolved subtree. A subsequent creator-verified ingestion added
-17 unique Standard media objects. A subsequent creator-verified tier review
-promoted the clean July 13 recording without changing its payload or stable
-identity, bringing the prior `main` state to 357 Standard and 128 Pre-Standard
-records. The next ingestion added three creator-verified August 2026 Standard
-recordings, including the first 14 × 17 in record and the first member of a
-recording sequence for which `Rec02` remains expected. This update adds the first
-two recordings in a separate August 22 14 × 17 in sequence; `Rec03` is expected,
-and the sequence endpoint is not yet claimed.
-A later creator-confirmed filename correction preserves the complete
-`Rec01`–`Rec15` order of 15 existing 30 × 40 in recordings dated June 18–30.
-Their media payloads, stable IDs, hashes, metadata membership, and release
-counts are unchanged.
-Two records from the 17-object ingestion and the promoted July 13 record are
-explicitly documented as shortened derivatives rather than full-duration
-masters.
-
-| Collection tier | Published MP4s | Indexed rows | Date coverage | Metadata state |
-| --- | ---: | ---: | --- | --- |
-| `standard` | 362 direct files | 362 | 2025-07-13–2026-08-22 | Complete core technical metadata for every direct Standard file |
-| `pre_standard` | 128 | 128 | 2024-09-17–2025-07-09, plus 9 unknown dates | Complete core technical metadata; historical descriptive and provenance gaps remain |
-| Earlier archive (unpublished) | 0 public videos | 0 | Historical scope 2012–2016 | More than 8 TB held outside this release; ingestion pending |
-
-**Current published index:** `main` contains 490 rows: 362 Standard and 128
-Pre-Standard. The preceding v0.1 state at revision
-`339e6149de130cbe2d001f7a0e5247872bc788ec` exposed 465 rows: 335 Standard and
-130 Pre-Standard. v0.2 added three previously unindexed Standard files and
-removed one Pre-Standard row whose media did not meet the ownership and
-provenance threshold. v0.3 added stable Pre-Standard identities and technical
-metadata. The post-v0.3 provenance correction promotes one previously
-unresolved, distinct Standard recording and corrects a separate record's
-physical finish date and time. The later 17-record Standard ingestion applies
-technical and provenance criteria without filtering records by aesthetic
-completion or perceived artistic quality. The later July 13 promotion applies
-the same rule to a clean shortened record and moves the documented Standard
-boundary coherently rather than creating a one-file exception.
-
-The Hub configurations use the split name `archive`. No official
-train/validation/test partition has been defined.
-
-## Viewer and Metadata Discovery
-
-The release exposes two explicit configurations so metadata-complete canonical
-records are not silently mixed with historically less complete records:
-
-- `canonical/archive` is the default and loads root `metadata.csv` with the 362
-  direct files in `Standard_Time_Lapses/`
-- `pre_standard/archive` loads `Pre_Standard_Time_Lapses/metadata.csv` with the
-  128 direct files in that folder
-
-Each configuration has the same declared 29-column schema. Stored dimensions
-and byte sizes are nullable integers, `has_audio` is a nullable boolean, and
-encoded frame rate remains a float because historical encodings include
-fractional reported rates. Undocumented values load as null rather than as
-zero or false. Both indexes declare tier membership directly: the root index sets
-`collection_tier = standard` and `is_canonical = true`; the Pre-Standard CSV
-sets `collection_tier = pre_standard` and `is_canonical = false`.
-
-Published-index completeness is defined by the 362 rows in `canonical/archive`
-plus the 128 rows in `pre_standard/archive` and their generated Parquet
-exports. Hugging Face's separate column Statistics job is an auxiliary,
-asynchronous surface; its availability is not used to claim or reject
-row-level completeness.
-
-The configuration lists the two active `metadata.csv` files and only direct
-MP4 paths in `Standard_Time_Lapses/` and `Pre_Standard_Time_Lapses/`. It does
-not use a recursive canonical glob, so the nested
-`Standard_Time_Lapses/Provenance/` subtree is excluded.
-
-## Overview
-
-`time-lapse-artifacts` documents analog drawing processes across different
-recording periods and acquisition conditions. Raw video is the primary record.
-Metadata identifies, organizes, compares, and documents recordings without
-imposing aesthetic scores or stylistic labels.
-
-The collection is a single-creator longitudinal archive. This makes it useful
-for studying within-practice change, but it does not represent artists,
-materials, studios, or drawing practices broadly.
-
-## Repository Structure
-
-### `Standard_Time_Lapses/`
-
-The directory contains 362 direct MP4 files. `metadata.csv` is their complete
-machine-readable canonical index: every direct file has one validated row with
-core technical metadata. Direct placement alone is not sufficient for future
-additions; metadata and release validation are required.
-
-Each canonical metadata row now includes:
-
-- a persistent `record_id`
-- `collection_tier = standard`
-- `is_canonical = true`
-- `acquisition_protocol_version = standard-2025-07-13`
-- descriptive session fields
-- encoded video properties
-- repository content hash and size
-- provenance fields where documented
-
-Files use a structured filename convention described in `SCHEMA.md`. A
-filename is descriptive, but it is not the stable identity of a record;
-external references should use `record_id`.
-
-### `Standard_Time_Lapses/Provenance/`
-
-This subtree contains supporting historical records and retained exceptions.
-It is not part of the canonical record set.
-
-`2026-07-31/` preserves the completed provenance release, including mappings
-between historical `Series_9x12` filenames and canonical records. The former
-full duplicate video snapshot is not retained. Relationships are preserved
-through mappings, hashes, metadata, and repository history.
-
-`Unresolved_Series_9x12/` contains distinct historical recordings that do not
-yet have enough documentation for promotion into the canonical collection.
-
-### `Pre_Standard_Time_Lapses/`
-
-These 128 recordings predate the standard acquisition protocol. They are
-published for archival continuity but are not interchangeable with canonical
-standard records. Each now has a stable `record_id`, exact Hub content hash and
-size, playback duration, stored dimensions and orientation, frame rate, codec,
-pixel format, container, and audio-stream presence. Historical dates, times,
-materials, and provenance remain incomplete where evidence is unavailable.
-Missing values must not be interpreted as zero, false, or evidence that a
-property was absent.
-
-The folder-local `metadata.csv` is the active index for these 128 videos and is
-loaded by the `pre_standard/archive` configuration. It follows the same
-declared 29-field schema as the canonical index while leaving undocumented
-historical fields empty.
-
-Material that does not meet the archive's ownership and provenance threshold
-is excluded from both the published media and the active metadata index.
-
-### `Earlier_Archive_2012_2016/`
-
-More than 8 TB of earlier material is held outside this dataset. It consists
-primarily of uploaded 1080p drawing videos, with some livestream-derived
-material. At the audited snapshot it contains no public video data. References
-to 2012–2016 therefore describe archive scope, not current downloadable
-coverage.
-
-## Metadata and Provenance
-
-The metadata distinguishes documented facts, established historical
-relationships, and unresolved information. Evidence may include:
-
-- exact file/blob identity
-- original filenames and repository paths
-- file sizes and hashes
-- duration comparison
-- visual continuity across recordings
-- documented physical references
-- repository commit history
-
-Uncertain relationships are not promoted to verified relationships solely
-because dates or filenames look similar.
-
-The active CSV files and live Viewer use semicolons for multiple `tool` and
-`medium` values, for example `Pencil;FountainPen` and `Graphite;Ink`. A pipe
-(`|`) is **not** a valid separator in v0.2. The two fields are independent
-observed-value lists; equal list lengths and positional pairing are not
-guaranteed. See `SCHEMA.md`.
-
-`encoded_frame_rate` is encoded playback rate. It is not the original temporal
-sampling rate of the drawing process.
-
-## Acquisition and Stored-Video Orientation
-
-The acquisition protocol effective July 13, 2025 is documented in
-`Archive_Specifications.md`.
-
-The protocol's capture orientation and a file's stored pixel orientation are
-different concepts. The `orientation`, `width_px`, and `height_px` metadata
-describe the published encoded file. Historical canonicalization may include a
-rotation, crop, or transcode; those transformations are documented only where
-evidence currently exists and must not be inferred from dimensions alone.
-
-The July 13, 2025 protocol boundary is explicitly encoded in canonical
-metadata. It supports era-aware comparison of repeated physical-media practice,
-but it is an acquisition change, not a skill-change label. Differences across
-that boundary may reflect capture conditions as well as practice development.
-
-## Annotation State
-
-Session-level descriptive and provenance metadata are curated by the creator
-from the physical practice, filenames, file properties, and retained historical
-evidence. This is the scope of `annotations_creators: expert-generated`; it does
-not mean that frame-level task labels exist. Likewise, `language: en` describes
-the filename vocabulary, metadata, and documentation, not incidental audio.
-
-The `video-classification` task facet refers to possible session-level targets
-such as documented tool, medium, and support. The release does not define label
-encodings, an official benchmark, or train/validation/test partitions.
-
-The videos themselves are primarily raw and unannotated. The release does not
-provide:
-
-- frame-level bounding boxes or segmentation masks
-- hand, pen-tip, pose, or stroke labels
-- aesthetic or quality scores
-- imposed stylistic classifications
-- calibrated physical trajectories
-- original capture timestamps for individual time-lapse frames
-
-Researchers may derive annotations, but derived labels should identify the
-source `record_id` and pinned repository revision.
-
-## Intended and Unsupported Uses
-
-### Reasonable uses in the current release
-
-- archival and drawing-process research
-- qualitative within-creator analysis of practice and skill development across
-  repeated physical-media sessions
-- self-supervised video representation experiments
-- frame-change, scene, and workspace analysis
-- development of annotation and tracking methods
-
-### Uses requiring additional validation or calibration
-
-- hand or pen-tip tracking
-- optical-flow comparison across acquisition eras
-- temporal behavior analysis
-- real-world trajectory, velocity, acceleration, or motor-control measurement
-
-The release does not currently provide capture intervals, acceleration factors,
-source-frame timestamps, camera calibration, or pixel-to-physical coordinate
-mapping. Encoded time-lapse playback must not be treated as real drawing time.
-
-### Not validated
-
-- population-level claims about artists or drawing behavior
-- clinical, biometric, authorship, or identity inference
-- a leakage-safe training or evaluation benchmark
-- commercial use outside the CC BY-NC 4.0 terms
-
-## Limitations and Sources of Bias
-
-- The archive documents one creator and one evolving practice.
-- Current public video coverage begins in 2024, not 2012.
-- The standard and pre-standard tiers have substantially different historical
-  descriptive/provenance completeness and acquisition conditions.
-- The workspace can contain hands, tools, phones, tablets, reference material,
-  and other objects that may create visual shortcuts or occlusion.
-- Stored resolution and frame rate do not establish physical or temporal
-  calibration.
-- Large files make exhaustive inspection and replication expensive.
-- No official leakage-safe split exists.
-
-## Rights, Privacy, and Audio
-
-The creator confirms ownership of the published video files and depicted
-creator-owned drawings. Material that cannot pass the ownership and provenance
-review is not part of the active public index and is not distributed by this
-release. This statement does not independently grant rights in incidental
-third-party material that may appear on screens, in references, or in captured
-audio.
-
-Nearly all published masters retain an audio stream. `has_audio` records stream
-presence only; it does not establish that the stream contains meaningful
-signal. Users are responsible for reviewing audio, visible screens, references,
-reflections, tattoos, and other potentially identifying or third-party content
-before redistribution or model release. A future proxy release should remove
-audio by default while preserving the archival masters.
-
-## Access and Reproducibility
-
-The active 490-video release contains 1,984,749,320,057 bytes of video
-(approximately 1.98 TB, or 1.81 TiB). Canonical files are often several
-gigabytes each, so users should select records through `metadata.csv` before
-downloading video.
-
-### Bandwidth-safe Quick Start
-
-Install Hugging Face Datasets, stream the archive, and disable decoding while
-selecting records:
-
-```python
-from datasets import Video, load_dataset
-
-dataset = load_dataset(
-    "maxwellinked/time-lapse-artifacts",
-    "canonical",
-    split="archive",
-    streaming=True,
-)
-metadata = dataset.cast_column("video", Video(decode=False))
-first = next(iter(metadata))
-print(first["video"]["path"], first["tool"], first["medium"])
-```
-
-This exposes the complete metadata schema without transferring video bytes.
-Default decoded row access additionally requires `torchcodec` and a compatible
-video-decoding stack. Use `streaming=True` unless a full archive download is
-intentional.
-
+---
+license: cc-by-nc-4.0
+pretty_name: Time-Lapse Artifacts
+annotations_creators:
+- expert-generated
+source_datasets:
+- original
+size_categories:
+- n<1K
+task_categories:
+- video-classification
+- feature-extraction
+tags:
+- drawing
+- longitudinal-study
+- traditional-art
+- provenance
+- single-subject
+- video
+- computer-vision
+- time-lapse
+- human-motion
+dataset_info:
+- config_name: canonical
+  features:
+  - name: video
+    dtype: video
+  - name: record_id
+    dtype: large_string
+  - name: collection_tier
+    dtype: large_string
+  - name: is_canonical
+    dtype: bool
+  - name: acquisition_protocol_version
+    dtype: large_string
+  - name: date
+    dtype: large_string
+  - name: time
+    dtype: large_string
+  - name: tool
+    dtype: large_string
+  - name: medium
+    dtype: large_string
+  - name: support
+    dtype: large_string
+  - name: dimensions
+    dtype: large_string
+  - name: duration_seconds
+    dtype: float64
+  - name: width_px
+    dtype: int64
+  - name: height_px
+    dtype: int64
+  - name: orientation
+    dtype: large_string
+  - name: encoded_frame_rate
+    dtype: float64
+  - name: video_codec
+    dtype: large_string
+  - name: pixel_format
+    dtype: large_string
+  - name: container
+    dtype: large_string
+  - name: has_audio
+    dtype: bool
+  - name: hub_xet_hash
+    dtype: large_string
+  - name: original_filename
+    dtype: large_string
+  - name: provenance_status
+    dtype: large_string
+  - name: legacy_provenance_path
+    dtype: large_string
+  - name: legacy_related_references
+    dtype: large_string
+  - name: evidence_method
+    dtype: large_string
+  - name: provenance_reference_duration_delta_seconds
+    dtype: float64
+  - name: size_bytes
+    dtype: int64
+  - name: notes
+    dtype: large_string
+  splits:
+  - name: archive
+    num_examples: 362
+- config_name: pre_standard
+  features:
+  - name: video
+    dtype: video
+  - name: record_id
+    dtype: large_string
+  - name: collection_tier
+    dtype: large_string
+  - name: is_canonical
+    dtype: bool
+  - name: acquisition_protocol_version
+    dtype: large_string
+  - name: date
+    dtype: large_string
+  - name: time
+    dtype: large_string
+  - name: tool
+    dtype: large_string
+  - name: medium
+    dtype: large_string
+  - name: support
+    dtype: large_string
+  - name: dimensions
+    dtype: large_string
+  - name: duration_seconds
+    dtype: float64
+  - name: width_px
+    dtype: int64
+  - name: height_px
+    dtype: int64
+  - name: orientation
+    dtype: large_string
+  - name: encoded_frame_rate
+    dtype: float64
+  - name: video_codec
+    dtype: large_string
+  - name: pixel_format
+    dtype: large_string
+  - name: container
+    dtype: large_string
+  - name: has_audio
+    dtype: bool
+  - name: hub_xet_hash
+    dtype: large_string
+  - name: original_filename
+    dtype: large_string
+  - name: provenance_status
+    dtype: large_string
+  - name: legacy_provenance_path
+    dtype: large_string
+  - name: legacy_related_references
+    dtype: large_string
+  - name: evidence_method
+    dtype: large_string
+  - name: provenance_reference_duration_delta_seconds
+    dtype: float64
+  - name: size_bytes
+    dtype: int64
+  - name: notes
+    dtype: large_string
+  splits:
+  - name: archive
+    num_examples: 128
+configs:
+- config_name: canonical
+  default: true
+  features:
+  - name: video
+    dtype: video
+  - name: record_id
+    dtype: large_string
+  - name: collection_tier
+    dtype: large_string
+  - name: is_canonical
+    dtype: bool
+  - name: acquisition_protocol_version
+    dtype: large_string
+  - name: date
+    dtype: large_string
+  - name: time
+    dtype: large_string
+  - name: tool
+    dtype: large_string
+  - name: medium
+    dtype: large_string
+  - name: support
+    dtype: large_string
+  - name: dimensions
+    dtype: large_string
+  - name: duration_seconds
+    dtype: float64
+  - name: width_px
+    dtype: int64
+  - name: height_px
+    dtype: int64
+  - name: orientation
+    dtype: large_string
+  - name: encoded_frame_rate
+    dtype: float64
+  - name: video_codec
+    dtype: large_string
+  - name: pixel_format
+    dtype: large_string
+  - name: container
+    dtype: large_string
+  - name: has_audio
+    dtype: bool
+  - name: hub_xet_hash
+    dtype: large_string
+  - name: original_filename
+    dtype: large_string
+  - name: provenance_status
+    dtype: large_string
+  - name: legacy_provenance_path
+    dtype: large_string
+  - name: legacy_related_references
+    dtype: large_string
+  - name: evidence_method
+    dtype: large_string
+  - name: provenance_reference_duration_delta_seconds
+    dtype: float64
+  - name: size_bytes
+    dtype: int64
+  - name: notes
+    dtype: large_string
+  data_files:
+  - split: archive
+    path:
+    - metadata.csv
+    - Standard_Time_Lapses/*.mp4
+- config_name: pre_standard
+  features:
+  - name: video
+    dtype: video
+  - name: record_id
+    dtype: large_string
+  - name: collection_tier
+    dtype: large_string
+  - name: is_canonical
+    dtype: bool
+  - name: acquisition_protocol_version
+    dtype: large_string
+  - name: date
+    dtype: large_string
+  - name: time
+    dtype: large_string
+  - name: tool
+    dtype: large_string
+  - name: medium
+    dtype: large_string
+  - name: support
+    dtype: large_string
+  - name: dimensions
+    dtype: large_string
+  - name: duration_seconds
+    dtype: float64
+  - name: width_px
+    dtype: int64
+  - name: height_px
+    dtype: int64
+  - name: orientation
+    dtype: large_string
+  - name: encoded_frame_rate
+    dtype: float64
+  - name: video_codec
+    dtype: large_string
+  - name: pixel_format
+    dtype: large_string
+  - name: container
+    dtype: large_string
+  - name: has_audio
+    dtype: bool
+  - name: hub_xet_hash
+    dtype: large_string
+  - name: original_filename
+    dtype: large_string
+  - name: provenance_status
+    dtype: large_string
+  - name: legacy_provenance_path
+    dtype: large_string
+  - name: legacy_related_references
+    dtype: large_string
+  - name: evidence_method
+    dtype: large_string
+  - name: provenance_reference_duration_delta_seconds
+    dtype: float64
+  - name: size_bytes
+    dtype: int64
+  - name: notes
+    dtype: large_string
+  data_files:
+  - split: archive
+    path:
+    - Pre_Standard_Time_Lapses/metadata.csv
+    - Pre_Standard_Time_Lapses/*.mp4
+---
+
+# time-lapse-artifacts
+
+490 time-lapse recordings of one artist's traditional drawing practice across
+nearly two years (September 2024–August 22, 2026), with standardized acquisition
+since July 13, 2025. Across approximately 1.98 TB of video, the archive follows
+the same artist working in physical media—including pencil, ballpoint pen,
+fountain pen, brush, graphite, and ink—on fixed-format paper and illustration board.
+The release combines 362 canonical Standard videos and 128 earlier
+Pre-Standard recordings. Every published video has a persistent record ID,
+content hash, byte size, and encoded-stream metadata; historical session and
+provenance fields remain less complete in the Pre-Standard tier.
+
+In this dataset, provenance refers to the documented relationship between a
+physical drawing and its time-lapse record, rather than to histories of
+ownership or sale.
+
+An earlier 2012–2016 archive of more than 8 TB also exists, consisting
+primarily of uploaded 1080p drawing videos, with some livestream-derived
+material. It is not yet published in this dataset and is excluded from the
+current 490-record, 1.98-TB release totals. This is an active construction
+release.
+
+## Snapshot and Coverage
+
+These counts describe the current `main` branch. The immutable `v0.3.0` tag
+contains 467 rows: 338 Standard and 129 Pre-Standard. A later curator-verified
+provenance correction promoted one distinct Standard recording from the
+noncanonical unresolved subtree. A subsequent creator-verified ingestion added
+17 unique Standard media objects. A subsequent creator-verified tier review
+promoted the clean July 13 recording without changing its payload or stable
+identity, bringing the prior `main` state to 357 Standard and 128 Pre-Standard
+records. The next ingestion added three creator-verified August 2026 Standard
+recordings, including the first 14 × 17 in record and the first member of a
+recording sequence for which `Rec02` remains expected. This update adds the first
+two recordings in a separate August 22 14 × 17 in sequence; `Rec03` is expected,
+and the sequence endpoint is not yet claimed.
+A later creator-confirmed filename correction preserves the complete
+`Rec01`–`Rec15` order of 15 existing 30 × 40 in recordings dated June 18–30.
+Their media payloads, stable IDs, hashes, metadata membership, and release
+counts are unchanged.
+Two records from the 17-object ingestion and the promoted July 13 record are
+explicitly documented as shortened derivatives rather than full-duration
+masters.
+
+| Collection tier | Published MP4s | Indexed rows | Date coverage | Metadata state |
+| --- | ---: | ---: | --- | --- |
+| `standard` | 362 direct files | 362 | 2025-07-13–2026-08-22 | Complete core technical metadata for every direct Standard file |
+| `pre_standard` | 128 | 128 | 2024-09-17–2025-07-09, plus 9 unknown dates | Complete core technical metadata; historical descriptive and provenance gaps remain |
+| Earlier archive (unpublished) | 0 public videos | 0 | Historical scope 2012–2016 | More than 8 TB held outside this release; ingestion pending |
+
+**Current published index:** `main` contains 490 rows: 362 Standard and 128
+Pre-Standard. The preceding v0.1 state at revision
+`339e6149de130cbe2d001f7a0e5247872bc788ec` exposed 465 rows: 335 Standard and
+130 Pre-Standard. v0.2 added three previously unindexed Standard files and
+removed one Pre-Standard row whose media did not meet the ownership and
+provenance threshold. v0.3 added stable Pre-Standard identities and technical
+metadata. The post-v0.3 provenance correction promotes one previously
+unresolved, distinct Standard recording and corrects a separate record's
+physical finish date and time. The later 17-record Standard ingestion applies
+technical and provenance criteria without filtering records by aesthetic
+completion or perceived artistic quality. The later July 13 promotion applies
+the same rule to a clean shortened record and moves the documented Standard
+boundary coherently rather than creating a one-file exception.
+
+The Hub configurations use the split name `archive`. No official
+train/validation/test partition has been defined.
+
+## Viewer and Metadata Discovery
+
+The release exposes two explicit configurations so metadata-complete canonical
+records are not silently mixed with historically less complete records:
+
+- `canonical/archive` is the default and loads root `metadata.csv` with the 362
+  direct files in `Standard_Time_Lapses/`
+- `pre_standard/archive` loads `Pre_Standard_Time_Lapses/metadata.csv` with the
+  128 direct files in that folder
+
+Each configuration has the same declared 29-column schema. Stored dimensions
+and byte sizes are nullable integers, `has_audio` is a nullable boolean, and
+encoded frame rate remains a float because historical encodings include
+fractional reported rates. Undocumented values load as null rather than as
+zero or false. Both indexes declare tier membership directly: the root index sets
+`collection_tier = standard` and `is_canonical = true`; the Pre-Standard CSV
+sets `collection_tier = pre_standard` and `is_canonical = false`.
+
+Published-index completeness is defined by the 362 rows in `canonical/archive`
+plus the 128 rows in `pre_standard/archive` and their generated Parquet
+exports. Hugging Face's separate column Statistics job is an auxiliary,
+asynchronous surface; its availability is not used to claim or reject
+row-level completeness.
+
+The configuration lists the two active `metadata.csv` files and only direct
+MP4 paths in `Standard_Time_Lapses/` and `Pre_Standard_Time_Lapses/`. It does
+not use a recursive canonical glob, so the nested
+`Standard_Time_Lapses/Provenance/` subtree is excluded.
+
+## Overview
+
+`time-lapse-artifacts` documents analog drawing processes across different
+recording periods and acquisition conditions. Raw video is the primary record.
+Metadata identifies, organizes, compares, and documents recordings without
+imposing aesthetic scores or stylistic labels.
+
+The collection is a single-creator longitudinal archive. This makes it useful
+for studying within-practice change, but it does not represent artists,
+materials, studios, or drawing practices broadly.
+
+## Repository Structure
+
+### `Standard_Time_Lapses/`
+
+The directory contains 362 direct MP4 files. `metadata.csv` is their complete
+machine-readable canonical index: every direct file has one validated row with
+core technical metadata. Direct placement alone is not sufficient for future
+additions; metadata and release validation are required.
+
+Each canonical metadata row now includes:
+
+- a persistent `record_id`
+- `collection_tier = standard`
+- `is_canonical = true`
+- `acquisition_protocol_version = standard-2025-07-13`
+- descriptive session fields
+- encoded video properties
+- repository content hash and size
+- provenance fields where documented
+
+Files use a structured filename convention described in `SCHEMA.md`. A
+filename is descriptive, but it is not the stable identity of a record;
+external references should use `record_id`.
+
+### `Standard_Time_Lapses/Provenance/`
+
+This subtree contains supporting historical records and retained exceptions.
+It is not part of the canonical record set.
+
+`2026-07-31/` preserves the completed provenance release, including mappings
+between historical `Series_9x12` filenames and canonical records. The former
+full duplicate video snapshot is not retained. Relationships are preserved
+through mappings, hashes, metadata, and repository history.
+
+`Unresolved_Series_9x12/` contains distinct historical recordings that do not
+yet have enough documentation for promotion into the canonical collection.
+
+### `Pre_Standard_Time_Lapses/`
+
+These 128 recordings predate the standard acquisition protocol. They are
+published for archival continuity but are not interchangeable with canonical
+standard records. Each now has a stable `record_id`, exact Hub content hash and
+size, playback duration, stored dimensions and orientation, frame rate, codec,
+pixel format, container, and audio-stream presence. Historical dates, times,
+materials, and provenance remain incomplete where evidence is unavailable.
+Missing values must not be interpreted as zero, false, or evidence that a
+property was absent.
+
+The folder-local `metadata.csv` is the active index for these 128 videos and is
+loaded by the `pre_standard/archive` configuration. It follows the same
+declared 29-field schema as the canonical index while leaving undocumented
+historical fields empty.
+
+Material that does not meet the archive's ownership and provenance threshold
+is excluded from both the published media and the active metadata index.
+
+### `Earlier_Archive_2012_2016/`
+
+More than 8 TB of earlier material is held outside this dataset. It consists
+primarily of uploaded 1080p drawing videos, with some livestream-derived
+material. At the audited snapshot it contains no public video data. References
+to 2012–2016 therefore describe archive scope, not current downloadable
+coverage.
+
+## Metadata and Provenance
+
+The metadata distinguishes documented facts, established historical
+relationships, and unresolved information. Evidence may include:
+
+- exact file/blob identity
+- original filenames and repository paths
+- file sizes and hashes
+- duration comparison
+- visual continuity across recordings
+- documented physical references
+- repository commit history
+
+Uncertain relationships are not promoted to verified relationships solely
+because dates or filenames look similar.
+
+The active CSV files and live Viewer use semicolons for multiple `tool` and
+`medium` values, for example `Pencil;FountainPen` and `Graphite;Ink`. A pipe
+(`|`) is **not** a valid separator in v0.2. The two fields are independent
+observed-value lists; equal list lengths and positional pairing are not
+guaranteed. See `SCHEMA.md`.
+
+`encoded_frame_rate` is encoded playback rate. It is not the original temporal
+sampling rate of the drawing process.
+
+## Acquisition and Stored-Video Orientation
+
+The acquisition protocol effective July 13, 2025 is documented in
+`Archive_Specifications.md`.
+
+The protocol's capture orientation and a file's stored pixel orientation are
+different concepts. The `orientation`, `width_px`, and `height_px` metadata
+describe the published encoded file. Historical canonicalization may include a
+rotation, crop, or transcode; those transformations are documented only where
+evidence currently exists and must not be inferred from dimensions alone.
+
+The July 13, 2025 protocol boundary is explicitly encoded in canonical
+metadata. It supports era-aware comparison of repeated physical-media practice,
+but it is an acquisition change, not a skill-change label. Differences across
+that boundary may reflect capture conditions as well as practice development.
+
+## Annotation State
+
+Session-level descriptive and provenance metadata are curated by the creator
+from the physical practice, filenames, file properties, and retained historical
+evidence. This is the scope of `annotations_creators: expert-generated`; it does
+not mean that frame-level task labels exist. Likewise, `language: en` describes
+the filename vocabulary, metadata, and documentation, not incidental audio.
+
+The `video-classification` task facet refers to possible session-level targets
+such as documented tool, medium, and support. The release does not define label
+encodings, an official benchmark, or train/validation/test partitions.
+
+The videos themselves are primarily raw and unannotated. The release does not
+provide:
+
+- frame-level bounding boxes or segmentation masks
+- hand, pen-tip, pose, or stroke labels
+- aesthetic or quality scores
+- imposed stylistic classifications
+- calibrated physical trajectories
+- original capture timestamps for individual time-lapse frames
+
+Researchers may derive annotations, but derived labels should identify the
+source `record_id` and pinned repository revision.
+
+## Intended and Unsupported Uses
+
+### Reasonable uses in the current release
+
+- archival and drawing-process research
+- qualitative within-creator analysis of practice and skill development across
+  repeated physical-media sessions
+- self-supervised video representation experiments
+- frame-change, scene, and workspace analysis
+- development of annotation and tracking methods
+
+### Uses requiring additional validation or calibration
+
+- hand or pen-tip tracking
+- optical-flow comparison across acquisition eras
+- temporal behavior analysis
+- real-world trajectory, velocity, acceleration, or motor-control measurement
+
+The release does not currently provide capture intervals, acceleration factors,
+source-frame timestamps, camera calibration, or pixel-to-physical coordinate
+mapping. Encoded time-lapse playback must not be treated as real drawing time.
+
+### Not validated
+
+- population-level claims about artists or drawing behavior
+- clinical, biometric, authorship, or identity inference
+- a leakage-safe training or evaluation benchmark
+- commercial use outside the CC BY-NC 4.0 terms
+
+## Limitations and Sources of Bias
+
+- The archive documents one creator and one evolving practice.
+- Current public video coverage begins in 2024, not 2012.
+- The standard and pre-standard tiers have substantially different historical
+  descriptive/provenance completeness and acquisition conditions.
+- The workspace can contain hands, tools, phones, tablets, reference material,
+  and other objects that may create visual shortcuts or occlusion.
+- Stored resolution and frame rate do not establish physical or temporal
+  calibration.
+- Large files make exhaustive inspection and replication expensive.
+- No official leakage-safe split exists.
+
+## Rights, Privacy, and Audio
+
+The creator confirms ownership of the published video files and depicted
+creator-owned drawings. Material that cannot pass the ownership and provenance
+review is not part of the active public index and is not distributed by this
+release. This statement does not independently grant rights in incidental
+third-party material that may appear on screens, in references, or in captured
+audio.
+
+Nearly all published masters retain an audio stream. `has_audio` records stream
+presence only; it does not establish that the stream contains meaningful
+signal. Users are responsible for reviewing audio, visible screens, references,
+reflections, tattoos, and other potentially identifying or third-party content
+before redistribution or model release. A future proxy release should remove
+audio by default while preserving the archival masters.
+
+## Access and Reproducibility
+
+The active 490-video release contains 1,984,749,320,057 bytes of video
+(approximately 1.98 TB, or 1.81 TiB). Canonical files are often several
+gigabytes each, so users should select records through `metadata.csv` before
+downloading video.
+
+### Bandwidth-safe Quick Start
+
+Install Hugging Face Datasets, stream the archive, and disable decoding while
+selecting records:
+
+```python
+from datasets import Video, load_dataset
+
+dataset = load_dataset(
+    "maxwellinked/time-lapse-artifacts",
+    "canonical",
+    split="archive",
+    streaming=True,
+)
+metadata = dataset.cast_column("video", Video(decode=False))
+first = next(iter(metadata))
+print(first["video"]["path"], first["tool"], first["medium"])
+```
+
+This exposes the complete metadata schema without transferring video bytes.
+Default decoded row access additionally requires `torchcodec` and a compatible
+video-decoding stack. Use `streaming=True` unless a full archive download is
+intentional.
+
 Use `"pre_standard"` as the configuration name to stream the earlier tier.
 
-For reproducible work:
-
-1. Pin a repository commit or release tag.
-2. Record the selected `record_id` values.
-3. Preserve the published `hub_xet_hash` values.
-4. State whether audio was retained.
-5. Document all rotation, crop, sampling, decoding, and proxy-generation steps.
+### Download and Verify One Record
 
-Run the included validator before publishing a metadata change:
+Install `huggingface_hub`, then use the included helper with a stable
+`record_id`:
 
 ```bash
-python tools/validate_metadata.py metadata.csv \
-  --pre-standard-metadata Pre_Standard_Time_Lapses/metadata.csv
+python -m pip install huggingface_hub
 ```
 
-`tools/enrich_prestandard.py` reproduces the Pre-Standard technical fields
-from a pinned Hub inventory and MP4 container headers. It uses HTTP range
-requests through FFmpeg; it does not intentionally download complete videos.
-`tools/capture_hub_inventory.py` records the corresponding Xet file IDs from
-resolve headers without following redirects or transferring video payloads.
+The helper resolves the requested revision to an immutable commit, checks the
+indexed byte size and Xet identity against the pinned Hub headers, and reports
+the ordinary LFS-compatible SHA-256 separately.
 
-The v0.2 index can be regenerated from the pinned 335-row source index plus the
-three audited additions:
+Check a record without downloading its video:
 
 ```bash
-python tools/repair_metadata.py source_metadata.csv metadata.csv \
-  --additions tools/metadata_additions_v0.2.csv
+python tools/download_verified.py tla-a66bdad6c903b89f --check-only
 ```
 
-## Versioning
+Download that record and verify its local byte size and SHA-256:
 
-The repository is under active construction. Record identity is carried by
-`record_id`; a filename may be corrected without creating a new conceptual
-record. Content replacement must retain provenance and should receive a new
-content hash.
-
-See `CHANGELOG.md` for release-level changes.
+```bash
+python tools/download_verified.py tla-a66bdad6c903b89f \
+  --revision "<commit-or-tag>" \
+  --output-dir downloads
+```
 
-## Documentation
+`hub_xet_hash` is an Xet file ID, not the SHA-256 of the downloaded bytes. The
+helper verifies both identities without conflating them. Video downloads may
+be many gigabytes; use `--check-only` first.
 
+For reproducible work:
+
+1. Pin a repository commit or release tag.
+2. Record the selected `record_id` values.
+3. Preserve the published `hub_xet_hash` values.
+4. State whether audio was retained.
+5. Document all rotation, crop, sampling, decoding, and proxy-generation steps.
+
+Run the included validator before publishing a metadata change:
+
+```bash
+python tools/validate_metadata.py metadata.csv \
+  --pre-standard-metadata Pre_Standard_Time_Lapses/metadata.csv
+```
+
+`tools/enrich_prestandard.py` reproduces the Pre-Standard technical fields
+from a pinned Hub inventory and MP4 container headers. It uses HTTP range
+requests through FFmpeg; it does not intentionally download complete videos.
+`tools/capture_hub_inventory.py` records the corresponding Xet file IDs from
+resolve headers without following redirects or transferring video payloads.
+
+The v0.2 index can be regenerated from the pinned 335-row source index plus the
+three audited additions:
+
+```bash
+python tools/repair_metadata.py source_metadata.csv metadata.csv \
+  --additions tools/metadata_additions_v0.2.csv
+```
+
+## Versioning
+
+The repository is under active construction. Record identity is carried by
+`record_id`; a filename may be corrected without creating a new conceptual
+record. Content replacement must retain provenance and should receive a new
+content hash.
+
+See `CHANGELOG.md` for release-level changes.
+
+## Documentation
+
 - `metadata.csv` — canonical machine-readable index
 - `Pre_Standard_Time_Lapses/metadata.csv` — active pre-standard public index
+- `LICENSE` — CC BY-NC 4.0 notice and rights-scope qualification
 - `SCHEMA.md` — filename and metadata contracts
 - `Archive_Specifications.md` — acquisition specifications and known gaps
 - `VALIDATION.md` — validation scope and current results
+- `RELEASE_MANIFEST.json` — historical v0.2.0 release-candidate manifest; it
+  does not describe current `main` or provide checksums for the video payloads
 - `tools/capture_hub_inventory.py` — pinned Hub/Xet identity inventory
+- `tools/download_verified.py` — selected download and byte-integrity check
 - `tools/enrich_prestandard.py` — pinned Pre-Standard technical enrichment
-- `tools/validate_metadata.py` — cross-tier metadata and repository checks
-- `Standard_Time_Lapses/Provenance/` — historical evidence and mappings
-
-## Citation
-
-Until a DOI-backed release is available, cite the dataset and pinned revision:
-
-```bibtex
-@dataset{maxwellinked_time_lapse_artifacts_2026,
-  author    = {maxwellinked},
-  title     = {time-lapse-artifacts},
-  year      = {2026},
-  publisher = {Hugging Face},
-  url       = {https://huggingface.co/datasets/maxwellinked/time-lapse-artifacts},
-  note      = {Active construction release; include the repository revision used}
-}
-```
-
-## License
-
-The dataset is released under **CC BY-NC 4.0**. The license applies only to
-material for which the licensor holds the necessary rights. Users must conduct
-their own review of incidental third-party content and downstream use.
+- `tools/validate_metadata.py` — cross-tier metadata and repository checks
+- `Standard_Time_Lapses/Provenance/` — historical evidence and mappings
+
+## Citation
+
+Until a DOI-backed release is available, cite the dataset and pinned revision:
+
+```bibtex
+@dataset{maxwellinked_time_lapse_artifacts_2026,
+  author    = {maxwellinked},
+  title     = {time-lapse-artifacts},
+  year      = {2026},
+  publisher = {Hugging Face},
+  url       = {https://huggingface.co/datasets/maxwellinked/time-lapse-artifacts},
+  note      = {Active construction release; include the repository revision used}
+}
+```
+
+## License
+
+The dataset is released under **CC BY-NC 4.0**. The license applies only to
+material for which the licensor holds the necessary rights. Users must conduct
+their own review of incidental third-party content and downstream use.

tools/download_verified.py

@@ -0,0 +1,155 @@
+#!/usr/bin/env python3
+"""Download one indexed video from a pinned Hub revision and verify its bytes.
+
+The script resolves a branch or tag to an immutable commit, checks the selected
+metadata row against the Hub's resolve headers, and optionally downloads the
+video. After download it verifies both the exact byte size and the ordinary
+LFS-compatible SHA-256. The Xet file ID is checked separately because it is not
+the SHA-256 of the downloaded file.
+"""
+
+from __future__ import annotations
+
+import argparse
+import csv
+import hashlib
+from pathlib import Path
+from urllib.parse import quote
+
+from huggingface_hub import HfApi, hf_hub_download
+
+from capture_hub_inventory import read_identity
+
+
+DEFAULT_REPO_ID = "maxwellinked/time-lapse-artifacts"
+INDEX_PATHS = (
+    "metadata.csv",
+    "Pre_Standard_Time_Lapses/metadata.csv",
+)
+
+
+def load_record(repo_id: str, revision: str, record_id: str) -> dict[str, str]:
+    matches: list[dict[str, str]] = []
+    for index_path in INDEX_PATHS:
+        local_path = hf_hub_download(
+            repo_id=repo_id,
+            filename=index_path,
+            repo_type="dataset",
+            revision=revision,
+        )
+        with Path(local_path).open(encoding="utf-8", newline="") as handle:
+            for row in csv.DictReader(handle):
+                if row.get("record_id") == record_id:
+                    matches.append(row)
+
+    if not matches:
+        raise SystemExit(f"record_id not found: {record_id}")
+    if len(matches) != 1:
+        raise SystemExit(f"record_id is not unique across active indexes: {record_id}")
+    return matches[0]
+
+
+def sha256_file(path: Path) -> str:
+    digest = hashlib.sha256()
+    with path.open("rb") as handle:
+        for block in iter(lambda: handle.read(8 * 1024 * 1024), b""):
+            digest.update(block)
+    return digest.hexdigest()
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Download one indexed video and verify its pinned Hub identity."
+    )
+    parser.add_argument("record_id", help="Stable tla- record ID to download")
+    parser.add_argument(
+        "--repo-id",
+        default=DEFAULT_REPO_ID,
+        help=f"Dataset repository (default: {DEFAULT_REPO_ID})",
+    )
+    parser.add_argument(
+        "--revision",
+        default="main",
+        help="Branch, tag, or commit to resolve and pin (default: main)",
+    )
+    parser.add_argument(
+        "--output-dir",
+        type=Path,
+        default=Path("downloads"),
+        help="Local download directory (default: downloads)",
+    )
+    parser.add_argument(
+        "--check-only",
+        action="store_true",
+        help="Verify metadata and Hub headers without downloading the video",
+    )
+    parser.add_argument("--timeout", type=int, default=30)
+    parser.add_argument("--retries", type=int, default=2)
+    args = parser.parse_args()
+
+    commit = HfApi().dataset_info(args.repo_id, revision=args.revision).sha
+    if not commit:
+        raise SystemExit(f"unable to resolve revision: {args.revision}")
+
+    row = load_record(args.repo_id, commit, args.record_id)
+    file_name = row.get("file_name", "")
+    expected_xet = row.get("hub_xet_hash", "").lower()
+    try:
+        expected_size = int(row.get("size_bytes", ""))
+    except ValueError as exc:
+        raise SystemExit(f"invalid size_bytes for {args.record_id}") from exc
+    if not file_name or not expected_xet:
+        raise SystemExit(f"incomplete identity metadata for {args.record_id}")
+
+    encoded_path = quote(file_name, safe="/")
+    resolve_url = (
+        f"https://huggingface.co/datasets/{args.repo_id}/"
+        f"resolve/{commit}/{encoded_path}"
+    )
+    identity = read_identity(resolve_url, args.timeout, args.retries)
+
+    if identity["repoCommit"] != commit:
+        raise SystemExit("resolve response came from a different repository revision")
+    if identity["xetHash"] != expected_xet:
+        raise SystemExit("Hub Xet identity differs from the indexed hub_xet_hash")
+    if identity["linkedSize"] != expected_size:
+        raise SystemExit("Hub byte size differs from the indexed size_bytes")
+
+    print(f"record_id: {args.record_id}")
+    print(f"revision: {commit}")
+    print(f"file: {file_name}")
+    print(f"size_bytes: {expected_size}")
+    print(f"hub_xet_hash: {expected_xet}")
+    print(f"sha256: {identity['linkedEtag']}")
+
+    if args.check_only:
+        print("verified metadata against pinned Hub headers; video not downloaded")
+        return
+
+    downloaded = Path(
+        hf_hub_download(
+            repo_id=args.repo_id,
+            filename=file_name,
+            repo_type="dataset",
+            revision=commit,
+            local_dir=args.output_dir,
+        )
+    )
+    actual_size = downloaded.stat().st_size
+    if actual_size != expected_size:
+        raise SystemExit(
+            f"downloaded size mismatch: expected {expected_size}, got {actual_size}"
+        )
+
+    actual_sha256 = sha256_file(downloaded)
+    if actual_sha256 != identity["linkedEtag"]:
+        raise SystemExit(
+            "downloaded SHA-256 differs from the pinned Hub LFS-compatible identity"
+        )
+
+    print(f"downloaded_to: {downloaded.resolve()}")
+    print("verified downloaded byte size and SHA-256")
+
+
+if __name__ == "__main__":
+    main()