Float playback handoff
Date: 2026-09-24
Target: physical Samsung Galaxy S23, SM8550
Phrase: p01, 33,600 samples, 1.40 seconds at 24 kHz
Pipeline: Kokoro-82M, FP16 QNN AOT contexts, af_heart
The diagnostic runner previously converted every float sample to PCM16 and
created a WAV file before starting AudioTrack. The revised path validates
the float buffer with runtime extrema, writes float PCM directly, starts
playback, and performs oracle comparison and WAV creation while audio is
already playing.
| Metric | Before | After |
|---|---|---|
| Front | 21.3 ms | 22.3 ms |
| Generator | 341.6 ms | 341.4 ms |
| Prepared input to playback start | 1,650.6 ms | 780.7 ms |
| Audio SNR | 18.43 dB | 18.43 dB |
| Playback | complete | complete |
Prepared-input-to-playback handoff decreased by 869.9 ms, or 52.7%. The generator timing did not materially change. The measured improvement is host audio-path work removed from the critical path, not a DSP acceleration claim.
The runner still uses managed AudioTrack as a diagnostic bridge. The release
appliance target remains a persistent native AAudio stream.