Mimi's transformer carries an internal position counter across encode()
calls that the upstream `reset_state()` does NOT fully clear. When
TrainingDataset::load_from_manifest encodes ~80-100 clips back-to-back
during data prep, the counter overflows the 8192-position buffer and
panics with `narrow invalid args [8192, 32]`.
src/mimi.rs:
- cache the safetensors path on Mimi at construction
- new Mimi.reload() drops the inner Model and rebuilds from the
cached path (~200 ms on Metal)
src/training.rs:
- call generator.mimi.reload() every 50 clips during
load_from_manifest. Adds ~1 s overhead on a 200-clip corpus
(4 reloads × ~200 ms) vs the alternative of a hard panic.
- reset_state() before each encode in TrainingExample::from_audio
is kept (still useful to clear streaming chunk state).
Found while running the end-to-end personal-voice training pipeline on
a 20-minute YouTube source: the bug surfaces around clip 86 when
Mimi's transformer hits position 8181+. Filtering to short clips
alone didn't help — the cumulative state grows even with sub-12-second
inputs.
Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>