Files
watch_sceen_ai/wsai/backends/whisper_worker.py
EJClaw 51811ad251 perf(voice): run STT+TTS on the GPU by default with CPU fallback
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>
2026-08-18 21:02:52 +09:00

107 lines
3.9 KiB
Python

"""Persistent faster-whisper STT worker.
faster-whisper (ctranslate2) lives in its own Python (whisper312); loading the
model takes seconds, so we load it ONCE here and then serve transcription
requests over stdin/stdout. This process is launched with the whisper312
interpreter by wsai.backends.whisper.WhisperSTT.
Like the MeloTTS worker, model/backend chatter could corrupt the JSON protocol,
so on startup we split the streams: a private duplicate of the original stdout
carries the protocol, and fd 1 is redirected to fd 2 so any library print lands
on stderr instead (where the parent drains it for diagnostics).
Protocol (one JSON object per line, on the protocol channel):
<- {"wav": "/abs/path.wav", "language": "ko"}
-> {"ok": true, "text": "...", "language": "ko", "ms": 123}
-> {"ok": false, "error": "..."}
On startup, once the model is ready, it emits exactly one line:
-> {"ready": true, "ms": <load-ms>, "device": "cpu", "model": "small"}
"""
import json
import os
import sys
import time
# Split protocol from library noise BEFORE importing anything heavy.
_proto = os.fdopen(os.dup(1), "w", buffering=1) # private copy of real stdout
os.dup2(2, 1) # fd1 -> stderr, so stray library prints don't hit the protocol
def _emit(obj: dict) -> None:
_proto.write(json.dumps(obj, ensure_ascii=False) + "\n")
_proto.flush()
def _log(*a):
print(*a, file=sys.stderr, flush=True)
def main() -> None:
model_name = os.environ.get("WSAI_WHISPER_MODEL", "small")
requested = os.environ.get("WSAI_WHISPER_DEVICE", "auto") # cpu | cuda | auto
default_lang = os.environ.get("WSAI_WHISPER_LANGUAGE", "ko") or None
from faster_whisper import WhisperModel # heavy import; only in whisper venv
def _has_cuda() -> bool:
try:
import ctranslate2
return ctranslate2.get_cuda_device_count() > 0
except Exception:
return False
device = requested
if requested == "auto":
device = "cuda" if _has_cuda() else "cpu"
def _compute_for(dev: str) -> str:
# int8 on CPU keeps a small model fast; float16 is the usual CUDA choice.
return os.environ.get(
"WSAI_WHISPER_COMPUTE", "int8" if dev == "cpu" else "float16"
)
t0 = time.monotonic()
try:
model = WhisperModel(model_name, device=device, compute_type=_compute_for(device))
except Exception as exc:
# CUDA picked but unusable (missing libs, OOM): fall back to CPU rather
# than leaving the whole voice loop dead.
if device == "cuda":
_log(f"[whisper_worker] CUDA load failed ({exc}); falling back to CPU")
device = "cpu"
model = WhisperModel(model_name, device=device, compute_type=_compute_for(device))
else:
raise
compute = _compute_for(device)
load_ms = int((time.monotonic() - t0) * 1000)
_emit({"ready": True, "ms": load_ms, "device": device, "model": model_name})
_log(f"[whisper_worker] {model_name} ready in {load_ms} ms on {device}/{compute}")
for line in sys.stdin:
line = line.strip()
if not line:
continue
try:
req = json.loads(line)
wav = req["wav"]
language = req.get("language", default_lang)
s = time.monotonic()
segments, info = model.transcribe(
wav,
language=language,
beam_size=int(req.get("beam_size", 5)),
vad_filter=bool(req.get("vad_filter", True)),
)
text = "".join(seg.text for seg in segments).strip()
ms = int((time.monotonic() - s) * 1000)
_emit({"ok": True, "text": text, "language": info.language, "ms": ms})
except Exception as exc: # keep the worker alive across bad requests
_emit({"ok": False, "error": f"{type(exc).__name__}: {exc}"})
_log(f"[whisper_worker] error: {exc}")
if __name__ == "__main__":
main()