The first CUDA inference pays a large lazy cost (kernel autotune/cudnn) —
~10s for a cold TTS synth — which would blow the voice loop's ~1s budget on
the very first reply. Each worker now runs one dummy inference (TTS: a short
phrase; STT: 1s of silence) after model load and before emitting "ready", so
"ready" means "hot". Warmup failures are logged and never block startup.
Verified: first real call after startup is now TTS ~238ms / STT ~189ms
(was ~11s cold for TTS). 12 tests pass.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Both voice backends defaulted to CPU. Fix the "CUDA unavailable" gaps so
everything that benefits from the RTX 5050 uses it:
- MeloTTS venv had CPU-only torch (2.12.0+cpu) -> installed Blackwell-capable
torch/torchaudio 2.11.0+cu128 (sm_120 verified with a real GPU matmul).
- faster-whisper CUDA loaded but transcribe() died with "libcublas.so.12 not
found": installed nvidia-cublas-cu12 + nvidia-cudnn-cu12 into the whisper
venv and inject those nvidia/*/lib dirs into the worker's LD_LIBRARY_PATH at
spawn (the loader only honours it at exec).
- WSAI_WHISPER_DEVICE / WSAI_MELO_DEVICE now default to "auto": pick CUDA when
present, else CPU, and each worker falls back to CPU if a CUDA load fails so
the voice loop never dies on a GPU-less host.
Verified end-to-end through the real backend classes: both workers report
"ready on cuda"; steady-state STT ~170ms (was ~1350ms CPU), TTS ~4s first call
vs ~23s CPU. All 12 tests pass.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Adds a MeloTTS backend that runs the model in its own melo311 interpreter
as a long-lived worker (melo_worker.py), loaded once and fed synthesis
requests over a stdin/stdout JSON protocol. fd1 is split from fd2 in the
worker so MeloTTS's stdout progress chatter can't corrupt the protocol.
Each speak() writes a wav and hands the path to a pluggable sink (the
Discord voice step will swap in "play into the call"). factory wires
tts=melo; pipeline.aclose now also tears down the tts worker.
Verified (CPU): model load ~7.9s once, then a short reply synthesizes in
~0.86s (within the ~1s budget); wav is valid 44.1kHz PCM. GPU (cuda) is
selectable via WSAI_MELO_DEVICE for lower latency, pending GPU approval.
7 smoke tests still pass.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
