An ambience change read and decoded the whole bed on the main thread, about 40 ms a swap. 1.12.1 opens the bed as a looping FMOD stream that reads the archive through its file callbacks (`0x460b54` → `0x7a54d0`, `FSOUND_Stream_Open` at `0x7a5525`).
Now:
- MPQ files open for in-place reads, one sector at a time.
- The bed streams from the archive, opened on the IO pool. A newer swap drops an open still in flight.
- kira moves to 0.12.4 on symphonia 0.6. 0.5 sized PCM frames from `nBlockAlign`, which 98 stereo WAVs store as 2, so a streamed bed fell silent halfway.
- A fork patch stops a stream at its last packet instead of spinning.
- A sector that inflates short is refused.
Tests cover a bed's true length, a seamless loop, an off-thread open, the stop at the last packet and the refusal.
Fixes#700Fixes#8🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
