VALIDATION.md

# Validation Report

## Scope

The current post-v0.3 main-branch candidate validates:

- all 356 canonical Standard rows and direct Standard MP4 paths
- all 129 active Pre-Standard rows and direct Pre-Standard MP4 paths
- persistent record identity and cross-tier uniqueness
- exact Hub Xet file IDs and stored byte sizes
- container-header technical metadata for every active published MP4
- repository membership, filename rules, field types, numeric ranges, and
  stored-orientation consistency

One 6,587,685,497-byte provenance object is promoted to the canonical root,
and the distinct 496,296,535-byte object previously occupying its corrected
name is moved to its curator-confirmed April 4 path. No video bytes are
transcoded, replaced, downloaded in full, or newly uploaded. The promoted
object's properties were read from its public MP4 header using HTTP range
requests. Sizes and content identities were read from the Hub repository
inventory.

The later Standard ingestion adds 17 creator-verified media objects totaling
9,289,459,921 bytes. Every addition was fully decoded before upload, all 17
local SHA-256 identities are unique, and none matches an existing Hub media
object. The batch is indexed without changing the 29-field schema.

## Result

**PASS — zero structural validation errors**

| Check | Result |
| --- | ---: |
| Active indexed rows | 485 |
| Canonical Standard rows | 356 |
| Pre-Standard rows | 129 |
| Metadata columns per index | 29 |
| Unique persistent `record_id` values | 485 |
| Unique nonblank content hashes | 485 |
| Complete encoded-video metadata | 485/485 |
| Canonical repository paths matched | 356/356 |
| Pre-Standard repository paths matched | 129/129 |
| Stored-orientation conflicts | 0 |
| Duplicate active content hashes | 0 |

Both Hub builder configurations explicitly declare the same 29 features. This
prevents per-CSV inference from representing an integer-only canonical
`encoded_frame_rate` column as `int64` while representing historical
fractional rates as `float64` in the Pre-Standard configuration.

## Audited statistics

- Total indexed playback duration: 50.49 hours
- Canonical playback duration: 40.89 hours
- Pre-Standard playback duration: 9.60 hours
- Median active-record playback duration: 329.630 seconds
- Total indexed video size: 1.901 TB decimal
- Stored orientation: 473 portrait, 12 landscape
- Audio streams: 479 present, 6 absent
- Unknown finish dates: 9
- Unknown finish times: 62

## Outstanding warnings

1. Fifteen canonical 30×40 records use `support = Paper`, while
   `Archive_Specifications.md` describes the 30×40 support as Illustration
   Board. The curator must determine whether the rows or the specification are
   wrong; this release candidate does not manufacture a correction.
2. Two creator-confirmed Standard additions are shortened derivatives rather
   than full-duration masters. Their start/end limitations remain explicit in
   `notes`; neither is represented as a complete capture lineage.
3. The 2026-01-11 and 2026-02-08 additions each produced one non-monotonic
   duplicate video-timestamp warning during validation but decoded completely.
   The 2026-01-11 recording also has pronounced lighting variation.
4. Five Pre-Standard records retain `time = 00:00` while their finish date is
   unknown. Confirm whether those are documented midnight times or historical
   placeholders before normalizing them.
5. Two Pre-Standard records retain incomplete material fields because the
   filename evidence is insufficient or ambiguous.
6. Most masters retain an audio stream. Stream presence does not establish
   meaningful signal, and rights/privacy review remains necessary.
7. Encoded frame rate is playback rate and cannot be used as original
   drawing-time sampling.
8. The 2012–2016 layer has no public video payload at this snapshot.
9. Separate Hub configurations prevent tier mixing, but no leakage-safe
   train/validation/test partition has been defined.

## Reproduction

Validate both active indexes:

```bash
python tools/validate_metadata.py metadata.csv \
  --pre-standard-metadata Pre_Standard_Time_Lapses/metadata.csv
```

For the strongest repository-inventory check, first augment the pinned Hub API
JSON with the Xet file IDs returned by the same revision's resolve headers:

```bash
python tools/capture_hub_inventory.py \
  --repo-json repo_api_blobs.json \
  --revision "<revision-under-review>" \
  --output repo_inventory_xet.json
```

Then validate paths, Xet identities, and exact byte sizes together:

```bash
python tools/validate_metadata.py metadata.csv \
  --pre-standard-metadata Pre_Standard_Time_Lapses/metadata.csv \
  --repo-inventory-json repo_inventory_xet.json
```

A plain JSON list of repository paths is also accepted through the legacy
`--repo-files-json` spelling, but that checks membership only; it cannot
independently verify hashes or byte sizes.

Use `--viewer-json` only with a Viewer snapshot produced from the same
repository revision and configuration under review.

The Pre-Standard technical enrichment is reproducible from a pinned Hub API
response containing `siblings` with LFS metadata and an FFmpeg executable:

```bash
python tools/enrich_prestandard.py \
  --metadata Pre_Standard_Time_Lapses/metadata.csv \
  --repo-json repo_inventory_xet.json \
  --revision "<revision-under-review>" \
  --ffmpeg /path/to/ffmpeg \
  --cache prestandard_probe_cache.json \
  --output Pre_Standard_Time_Lapses/metadata.csv
```

The revision is intentionally explicit: reproducing against a moving branch
would weaken both identity and technical-metadata claims.

The canonical v0.2 index remains reproducible from its pinned 335-row source
plus the three audited additions:

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