SCHEMA.md

Schema

This document defines the contracts for canonical filenames and metadata.csv. Filenames are human-readable descriptions; record_id is the persistent machine identity.

Canonical Filename Format

YYYY-MM-DD.HHMM.Tool.Medium.Support.Dimensions[.RecNN].ext

Examples:

2025-07-15.0448.FountainPen.Ink.Paper.9x12.mp4
2026-06-29.UnknownTime.FountainPen.Ink.Paper.30x40.Rec11.mp4
2026-06-29.UnknownTime.FountainPen.Ink.Paper.30x40.Rec12.mp4

Filename fields

• YYYY-MM-DD — documented finish date.
• HHMM — documented finish time in 24-hour local civil time.
• UnknownTime — used when no reliable finish time is documented.
• Tool — drawing instrument, such as Pencil, FountainPen, BallpointPen, or Brush.
• Medium — applied material, such as Graphite or Ink.
• Support — drawing surface, such as Paper, IllustrationBoard, or WatercolorPaper.
• Dimensions — support dimensions in inches; order preserves support orientation, such as 9x12 or 12x9.
• RecNN — optional recording-sequence identifier used when documented order must be preserved or otherwise identical filenames require distinction. Numbering begins with Rec01 and may continue across finish dates.
• ext — file extension.

Filename rules

• Fields are separated by periods.
• Style and aesthetic classifications are excluded.
• TL is excluded because time-lapse is implicit in the primary collection.
• 0000 is reserved for a documented midnight finish time.
• RecNN identifies recording order only. It does not by itself establish a separate drawing, session, or completion state, and it does not reset merely because the documented finish date changes.
• UnknownTime records uncertainty; it is not replaced by an inferred time.
• Paper-surface variants such as HotPress and ColdPress may remain encoded in filenames until a dedicated metadata field is added.
• Historical relationships must not be inferred from filename similarity alone.

Tool and medium tokens in a filename describe documented materials, but older filenames do not always encode an unambiguous one-to-one pairing. Metadata must therefore preserve tool and medium sets without manufacturing positional pairs.

Canonical Metadata Contract

metadata.csv indexes the validated canonical subset of MP4 files stored directly in Standard_Time_Lapses/. Direct placement alone does not make a file canonical: every released canonical file must have exactly one metadata row, complete required technical fields, and the necessary rights and provenance clearance. The canonical index contains 362 validated records and covers every MP4 stored directly in Standard_Time_Lapses/ at the pinned revision.

The canonical index does not make provenance, unresolved, pre-standard, or legacy files canonical.

Identity and collection fields

Field	Type	Meaning
file_name	string	Repository-relative canonical video path.
record_id	string	Persistent identity in the form tla- plus 16 lowercase hexadecimal characters.
collection_tier	enum	standard for this index.
is_canonical	boolean	true for every row in this index.
acquisition_protocol_version	string	Protocol identifier; currently standard-2025-07-13.

The initial record_id values were generated from a namespaced SHA-256 of the published repository path. Once assigned, the stored value is authoritative and must be retained across filename corrections or tier changes. New tooling must assign an ID only when a record does not already have one. When a genuinely new record is promoted from a noncanonical holding, its ID is seeded from that object's prior archival path; it must not inherit an ID already attached to a different object at the corrected destination path.

Pre-Standard collection contract

Pre_Standard_Time_Lapses/metadata.csv indexes the 128 direct MP4 files in that folder. Each row uses collection_tier = pre_standard, is_canonical = false, and a blank acquisition_protocol_version. Pre-Standard status records a different acquisition/documentation era; it does not remove the requirements for stable identity, exact content hash and size, or encoded-stream metadata.

Dates, times, tools, media, support, and historical provenance may remain blank when the surviving evidence is insufficient. Those blanks are historical uncertainty, not failed technical ingestion.

Session and material fields

Field	Type	Meaning
date	YYYY-MM-DD	Documented finish date.
time	HH:MM or blank	Documented finish time; blank means unknown.
tool	semicolon list	Ordered unique set of documented tools.
medium	semicolon list	Ordered unique set of documented media.
support	string	Physical drawing surface.
dimensions	string	Support dimensions in inches, such as 9x12.

Multiple values use semicolons:

tool = Pencil;FountainPen
medium = Graphite;Ink

tool and medium are independent observed-value lists. Equal lengths and positional correspondence are not guaranteed. Repeated media are collapsed to one value. A future paired representation should use a structured field and must be based on documented evidence rather than token position.

Encoded-video fields

Field	Type	Meaning
duration_seconds	float	Encoded playback duration.
width_px	integer	Stored encoded width.
height_px	integer	Stored encoded height.
orientation	enum	Stored pixel orientation derived from width and height.
encoded_frame_rate	float	Encoded playback frame rate as reported by the container; fractional values are allowed.
video_codec	string	Encoded video codec.
pixel_format	string	Encoded pixel format.
container	string	Media container.
has_audio	boolean	Whether the stored file contains an audio stream.
hub_xet_hash	string	Lowercase 64-character Xet file ID from the pinned Hub resolve response's X-Xet-Hash header. This is distinct from the LFS-compatible SHA-256.
size_bytes	integer	Stored file size in bytes.

These fields describe the published encoded file. They do not establish the original frame-capture interval, real drawing duration, speed-up factor, camera calibration, capture orientation, rotation, crop, or transcode lineage.

Canonical status identifies the active representative of a Standard record; it does not assert that the encoded file is an unaltered or full-duration capture master. A shortened derivative may be canonical when it is the verified active representative and its limitation is disclosed in notes.

encoded_frame_rate must not be interpreted as drawing-time sampling rate.

Historical provenance fields

Field	Type	Meaning
original_filename	string or blank	Independently documented historical filename.
provenance_status	string or blank	Current relationship status.
legacy_provenance_path	string or blank	Verified historical repository path.
legacy_related_references	string or blank	Related candidates, aliases, or rejected references.
evidence_method	string or blank	Primary evidence used for the status.
provenance_reference_duration_delta_seconds	float or blank	Duration delta to a referenced historical file.
notes	string or blank	Human-readable evidence or qualification.

Blank provenance values mean that the field is not documented or not applicable in the current release. A blank must not be promoted to a verified relationship.

Observed provenance statuses include:

• legacy_match_verified
• legacy_aliases_verified
• legacy_duplicate_removed
• legacy_candidates_rejected
• direct_root_upload

Observed evidence methods include:

• blob_identity
• visual_continuity
• visual_comparison
• commit_history
• manual_confirmation
• blob_identity_and_physical_date

New enumerated values must be documented here before use.

Missing-Value Rules

• Blank means unknown, not documented, or not applicable according to the field description.
• Blank numeric values must remain blank; they are not zero.
• Blank booleans must remain blank; they are not false.
• Uncertain dates and times must not be reconstructed from unsupported clues.
• Pre-Standard descriptive/provenance metadata may be less complete, but every published record must carry a collection-tier distinction, stable ID, exact content identity, and complete core encoded-video metadata.

Required Validation

Before publication, the validator must confirm:

• unique record_id, file_name, and nonblank hub_xet_hash
• canonical paths remain directly under Standard_Time_Lapses/
• one consistent semicolon convention for multi-value fields
• valid dates, times, and dimensions
• complete core encoded-video metadata for every active Standard and Pre-Standard row
• orientation agrees with stored width and height
• canonical metadata paths match the canonical Viewer records
• every active standard and pre-standard metadata path resolves to a published repository file
• repository media absent from an active index is reported explicitly rather than silently treated as released data
• material lacking the necessary ownership or provenance clearance is absent from both active indexes

Run:

python tools/validate_metadata.py metadata.csv

Rebuild the v0.2 index from its pinned 335-row source and audited additions:

python tools/repair_metadata.py source_metadata.csv metadata.csv \
  --additions tools/metadata_additions_v0.2.csv