4.4 KiB
Music metadata hypothesis: actual Google CPU diagnostic
This known two-file diagnostic compares real audio evidence with real embedded metadata. It does not change production ranking or establish independent music quality, general abstention, or a higher media rating.
The preserved v1 run encoded eleven default audio windows and two whole-tag passages. Adding the whole passage left music memories at 2/4 first hits: the violin's English similarity increased, but stayed below the wrong piano.
The subsequent v2 policy was frozen in source commit 7055004 before inference.
It encodes artist, title, album, genre and composer separately, in fixed order
with a shared 2048-byte UTF-8 budget and the neutral document title File metadata.
The file score is the maximum of its actual evidence, with no weights or cutoff.
This is a hypothesis motivated by v1, not untouched held-out testing.
Recomputed results
All 65 original queries remain in the report. Three filter queries are explicitly unsupported. Among 62 executed queries, only seven positive queries name one of the two candidates; 50 positives name files outside this deliberately limited pool and cannot receive a quality score. Five unfiltered no-answer queries remain.
| Two-file diagnostic | Audio only | Whole tags v1 | Individual fields v2 |
|---|---|---|---|
| Music memories: correct first file | 2/4 | 2/4 | 4/4 |
| Music identity queries: correct first file | 2/3 | 2/3 | 3/3 |
| All eligible positives: correct first file | 4/7 | 4/7 | 7/7 |
| Eligible positives: recall within first five | 7/7 | 7/7 | 7/7 |
| Eligible positive MRR | 0.786 | 0.786 | 1.000 |
| No-answer queries returning candidates, failure | 5/5 | 5/5 | 5/5 |
The first-hit gains are q049, q050 and q056, with no scored positive
regression. English violin selected the literal composer field
Violinist WTD/LPC Jazz Band (cosine 0.73714); German violin selected the actual
title Jazz Violin Solo (0.73508). Their wrong piano audio maxima were 0.68972
and 0.70654 respectively. The piano memories retained their original audio hits.
This improvement also strengthens unrelated nearest neighbors: the purple-elephant violin negatives increased by 0.04994 and 0.04801 cosine, and the German quantum entanglement negative by 0.00749. All negatives still return files. Consequently, the diagnostic provides no abstention improvement and no safe rejection threshold. Metadata is useful evidence, not a calibrated confidence score.
Inputs, execution and limits
The actual piano tags identify Kimiko Ishizaka, Goldberg Variation 13, Classical and J.S. Bach. The violin tags identify Violinist WTD, Jazz Violin Solo, Jazz and the LPC Jazz Band. No instrument descriptions were generated from the waveform. Blank/missing whitelisted fields add no vector; encoder, comments, URLs and copyright are excluded. Misleading tags remain unverified literal evidence. Metadata citations have a field and text, never an invented playback timestamp.
V2 used actual Google EmbeddingGemma 2 Q8 through the same native
b11461-no-logits-v1 worker on CPU, one thread, 768 dimensions and a 2048-token
indexing context. Ten field encodes took 750.03 ms, excluding model startup
and query inference. It made zero audio inference calls: per-query audio
maxima were reused verbatim from the SHA-verified v1 report. Independent read-only
recomputation checked query equality and exact retained audio/whole-tag rankings
for all 62 executed rows. This tiny shared-VM measurement is not a throughput
guarantee or a production ANN/hybrid measurement.
- Frozen v2 plan SHA-256:
566bcd608ccf898abaceab32b247786e895368c8428b1bfa6e0bbb8396211b05. - Preserved v1 report SHA-256:
f985ba639a14b8c0288b8fa7812d580f179f31c8cad0c21d67531c8a4fddc5b6. - Ignored v2 report
.searchi/qa/music-fields-v2-results.json, 288944 bytes, SHA-256c13ceca2150059a21e10ee190893a66f5ac82570675e7725e54524c660a2ff30.
Reproduction commands and structural tests are in the evaluation tool README. Before deployment, evaluate independently frozen unseen music, missing/misleading metadata, additional instrument/style hard negatives and the complete mixed candidate pool. Production integration must retain real metadata field citations, source-byte/revision guards, strict filters and generation policy invalidation. The broader media quality gates and experimental rating remain unchanged.