VALIDATION.md

# Validation Report

## Scope

The v0.3 release candidate retains the v0.2 media membership and validates:

- all 338 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

No video payload was replaced, renamed, transcoded, or uploaded in this
metadata-only release candidate. Pre-Standard technical properties were read
from the existing public MP4 headers using HTTP range requests. Sizes and
content identities were read from the Hub repository inventory.

## Result

**PASS — zero structural validation errors**

| Check | Result |
| --- | ---: |
| Active indexed rows | 467 |
| Canonical Standard rows | 338 |
| Pre-Standard rows | 129 |
| Metadata columns per index | 29 |
| Unique persistent `record_id` values | 467 |
| Unique nonblank content hashes | 467 |
| Complete encoded-video metadata | 467/467 |
| Canonical repository paths matched | 338/338 |
| 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: 50.06 hours
- Canonical playback duration: 40.46 hours
- Pre-Standard playback duration: 9.60 hours
- Median active-record playback duration: 345.722 seconds
- Total indexed video size: 1.885 TB decimal
- Stored orientation: 455 portrait, 12 landscape
- Audio streams: 462 present, 5 absent
- Unknown finish dates: 9
- Unknown finish times: 59

## 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. 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.
3. Two Pre-Standard records retain incomplete material fields because the
   filename evidence is insufficient or ambiguous.
4. Most masters retain an audio stream. Stream presence does not establish
   meaningful signal, and rights/privacy review remains necessary.
5. Encoded frame rate is playback rate and cannot be used as original
   drawing-time sampling.
6. The 2012–2016 layer has no public video payload at this snapshot.
7. 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 5bd5b715e59e2b5943ecac85b1b6c7de4d03184c \
  --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 5bd5b715e59e2b5943ecac85b1b6c7de4d03184c \
  --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
```