jerry/buzz

mirror of https://github.com/block/buzz.git synced 2026-10-27 04:30:52 +00:00

Files

John Matthew Tennant d48b0e0eec feat(desktop): upgrade Pocket TTS model (#3266 )

## Context

Buzz Desktop currently installs an older Pocket TTS model bundle. The
current
bundle changes the tokenizer, learned BOS input, recurrent-state
contract, and
prompt behavior, so updating download URLs alone is not compatible.

## Summary

This PR upgrades Buzz Desktop to the current pinned Pocket TTS model. It
preserves existing product behavior and the hard 50-token model-input
limit
while adding the required runtime support, verified acquisition, and
crash-safe
cache migration.

## Changes

- Pins an immutable Pocket TTS revision, artifact names, exact byte
sizes,
SHA-256 checksums, Mary reference voice, and license.
- Loads the bundle-matched SentencePiece tokenizer, learned BOS
embedding, and
bundle-declared recurrent states.
- Uses one pinned Pocket TTS configuration; no precision or
model-version
selector is added.
- Preserves the resident engine's exact `<= 50` token contract without
changing
Desktop segmentation policy.
- Bumps the Pocket cache manifest to v4, verifies size and checksum
before
adoption, atomically swaps the cache, and recovers the last verified
cache
after interrupted installs, including an incomplete final directory.
- Keeps acquisition, cache migration, worker adoption, and tests within
the
existing Desktop implementation.
- Removes the obsolete model-quality harness, which was coupled to the
superseded production prompt and model layout.

## Related issue

None.

## Testing

Manual listening completed on the exact Desktop build. The updated model
improved speech quality and resolved the phrase-start and sample-onset
artifacts. Reproducible integrity and model checks are below.

## Screenshots

N/A. This changes model installation and speech synthesis, not a visual
surface.

## Reviewer-reproducible examples

### Before and after model identity

```sh
git show 35305bfc8fd456ca9a17caa1ddbfaabd87d46981:desktop/src-tauri/src/huddle/models.rs \
| grep -E 'sherpa-onnx-pocket-tts|TTS_MODEL_VERSION'

git show 211d17c58567448fe7ac95c4fa0ad2b88378849a:desktop/src-tauri/src/huddle/pocket_models.rs \
| grep -E 'MODEL_REPOSITORY|MODEL_REVISION|MODEL_PRECISION|MAX_TOKENS'
```

The target branch identifies the January bundle. The PR branch
identifies the
immutable April revision, INT8 precision, and 50-token maximum.

### Deterministic runtime validation

Use the pinned artifacts listed in `pocket_models.rs` and run the
model-dependent Pocket tests with the model directory supplied by the
test environment. The checked-in long-sentence fixture must preserve its
expected 48 and 44 token split and produce non-silent PCM.

### Manual listening validation

John listened to an untrimmed Pocket TTS onset-stress clip generated
from the exact user-provided passage, with every sentence synthesized
separately and identical 100 ms digital-silence boundaries. The clip
used no leading period, onset trimming, gain adjustment, or loudness
normalization.

The updated model produced better-quality speech and resolved the
start-of-sample artifacts.

---------

Signed-off-by: John Tennant <jtennant@block.xyz>
Signed-off-by: npub1mprnacetjua2xx3p5eddmhxyk6wv929ymm5py8kd2xfxurxahspqqlgyta <d8473ee32b973aa31a21a65adddcc4b69cc2a8a4dee8121ecd51926e0cddbc02@buzz.block.builderlab.xyz>
Co-authored-by: John Tennant <jtennant@block.xyz>
Co-authored-by: npub1mprnacetjua2xx3p5eddmhxyk6wv929ymm5py8kd2xfxurxahspqqlgyta <d8473ee32b973aa31a21a65adddcc4b69cc2a8a4dee8121ecd51926e0cddbc02@buzz.block.builderlab.xyz>

2026-07-31 07:00:15 -04:00