GR-004 — a gallery built with one embedding model is meaningless with another.
Cosine similarities across models are garbage but look entirely plausible, so
this fails silently and expensively; every measurement taken against a
mismatched pair would have been quietly wrong.
The stamp is the model basename plus a SHA-256 of its bytes, with embed_dim as
a cheap extra guard. The hash decides and the name explains, because neither
works alone: a name is a promise rather than a fact — models get re-exported in
place under an unchanged filename, which is exactly the case where the weights
differ and nothing else does — while a bare hash mismatch tells an operator
nothing actionable.
Mismatch is fatal in every mode with no bypass. Unstamped only warns, because
unstamped is unknown rather than known-bad, and an error firing on every legacy
gallery trains people to reach for the bypass reflexively. scripts/stamp_gallery.py
binds an existing gallery in place with no re-embedding, so the warning is a
migration step rather than a permanent state; --require-gallery-stamp promotes
it to an error once a site has migrated.
Two gaps found that would have defeated the requirement outright:
- Embedding dumps carried no stamp, so a replay — which has no live embedder —
had nothing to check the gallery against. Dumps now carry embedder_model and
embedder_sha256 as root attributes. Additive; schema_version stays 1. This is
the same gap the dump audit identified independently.
- --merge produced one file holding two embedding spaces, which no later check
can untangle. Merge paths now verify before writing.
The stamp also survives identity_matcher's calibration write-back, which would
otherwise have stripped it on the first analysis run — the check would have
worked exactly once.
Conflicts resolved additively: both branches appended a source to sae_gallery
and to the test target, and both edited the GR-004 register row.
Merged suite: 64 cases, 3199 assertions, passing on CPU with no GPU.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
TRACES: GR-004, VR-001 | SR-001
A gallery is only valid for the embedder that produced its vectors. Cosine
similarities across models are meaningless but *look* plausible, so the mistake
is silent and every measurement taken afterwards is suspect. Stamp the embedder
identity into the gallery at build; verify it at every load.
The stamp is the model file's basename plus the SHA-256 of its bytes (plus
embed_dim). The hash decides, the name explains. A name alone is a promise
rather than a fact — models get re-exported and overwritten in place under an
unchanged filename, which is exactly the case where the weights differ and
nothing else does. A hash alone is correct but unactionable in an error message.
SHA-256 is derived from the artefact, needs no registry kept current, and costs
~0.1s for a 250MB ONNX, memoised per process.
Mismatch is a hard error in every mode, with no bypass, naming both sides.
Unstamped legacy galleries warn loudly and proceed: unknown is not known-bad,
and hard-failing every pre-existing gallery would turn the check into something
people disable rather than trust. --require-gallery-stamp (or
SAE_REQUIRE_GALLERY_STAMP=1, which propagates to subprocesses) promotes that to
a hard error — the mode measurement work should run in. scripts/stamp_gallery.py
re-binds an existing gallery with no re-embedding, so "warn" is a cheap state to
leave rather than a permanent one.
Embedding dumps carry the same stamp: a replay has no live embedder, so the dump
is the embedder as far as the gallery is concerned. Derived galleries inherit
their source's stamp; --merge and the JSON gallery merge check before writing,
since one file holding two embedding spaces cannot be untangled afterwards.
Verified in: scene_analyze, scene_preview, the sae_kpn matcher binding,
replay.py, optimize.py (once per film at startup, before the first evaluation),
movienet_eval.py and both merge paths.
Stamp logic lives in src/gallery/embedder_stamp.{hpp,cpp} and its Python twin
scripts/sae_stamp.py, kept dependency-light so replay subprocesses do not pay
sae_gallery's requests/Pillow import to ask whether two models match.
Tests: 12 new cases in test_gallery_store.cpp covering the comparison logic,
both round trips, and the SHA-256 vectors that guarantee the C++ and hashlib
stamps agree. No ONNX or GPU required.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Implements the content-derived spectral-peak signature from
JRay-public-server/SPEC.md §3 so a truth file is self-identifying: 120 s
window centred on the media midpoint, mono at 11025 Hz, 4096/1024 Hann
STFT, 32 log-spaced bins over 300-3000 Hz, one byte per frame (5-bit peak
band + 2-bit energy class), base64, `v1:` prefix.
Audio decode is a second stream from the FFmpeg libraries the pipeline
already links for video; libswresample is added to the existing
ffmpeg_libs interface target. The FFT is written out rather than pulled
from a library for the same reason the plugin vendors one: the output has
to be bit-identical across two languages, so a dependency whose version
could change the numerics is a liability.
The server spec fixes the geometry but not enough to reproduce a byte
stream — Hann periodicity, band aggregation, the energy-class definition,
tie-breaking and the base64 alphabet are all unconstrained by it. Those
are pinned in audio_signature.hpp and mirrored in the golden fixture, so
the plugin can be implemented from the fixture alone.
IR-005: tests/fixtures/audio/ carries a deterministic 120 s tone (FLAC —
lossless, so identical PCM to the WAV make_fixture.py emits, and 3.5x
smaller in git) plus the signature it must produce, the decoded-PCM
checksum and the full parameter contract. That directory is the artefact
shared with the plugin repo; the PCM checksum is separate from the
signature so a codec-level difference is distinguishable from a DSP one.
IR-007: media under 120 s emits no signature. Same for a file with no
audio stream or one that will not open — UR-9 is an enhancement and must
never be able to break a fetch.
Verified against an independent Python reference implementation: same
bytes. All 32 bands and all 4 energy classes appear in the golden vector,
and the window-centring test wraps the fixture in 90 s of silence either
side and requires the golden value back.
Not wired into the truth-file output yet — that is the schema_version
bump under IR-002/IR-003 and is deliberately out of scope here.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
GPU-free, model-free tests for the pure logic: gallery HDF5 save/load
round-trips (actors, embeddings, embedded calibration) and legacy JSON
read back-compat; the calibration sigmoid fit, boundary inversion, and the
in-memory hash-keyed cache reuse/staleness; TrackGallery's diversity-buffer
eviction, novelty/spread safety gates, and promotion; FaceTracker's IoU/
embedding association and cross-cut track revival; and the GEMM similarity
backend (forced to CPU so the suite runs without a GPU).
Verified: all 39 test cases / 1640 assertions pass (cmake -DSAE_BUILD_TESTS=ON).
dtourolleandClaude Opus 5