04866559db
- Add FastAPI routes for surgery start/end, results, pending confirmation (WAV upload), and health checks. - Implement RTSP/Hikvision capture, consumable classification, session manager, MinIO/Baidu voice resolution, and DB persistence. - Add documentation (client API, video backends, staging checklist) and sample camera/RTSP config. - Add pytest suite (API contract, session manager, voice, repositories, pipeline persistence) and httpx dev dependency. - Replace deprecated HTTP_422_UNPROCESSABLE_ENTITY with HTTP_422_UNPROCESSABLE_CONTENT. - Fix SurgeryPipeline DB reads to use an explicit transaction with autobegin disabled. Made-with: Cursor
102 lines
2.8 KiB
Python
102 lines
2.8 KiB
Python
"""Decode WAV bytes to 16 kHz mono 16-bit PCM for Baidu short ASR."""
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from __future__ import annotations
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import io
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import shutil
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import subprocess
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import wave
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from typing import Final
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_BAIDU_RATE: Final[int] = 16000
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class WavDecodeError(ValueError):
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"""Uploaded bytes are not a valid WAV or cannot be converted."""
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def wav_bytes_to_pcm16k_mono_s16le(wav_bytes: bytes) -> bytes:
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"""
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Prefer ffmpeg for arbitrary channel count / sample rate.
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Falls back to stdlib `wave` when ffmpeg is unavailable (16-bit PCM only).
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"""
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if not wav_bytes:
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raise WavDecodeError("Empty audio payload")
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ffmpeg = shutil.which("ffmpeg")
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if ffmpeg:
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return _ffmpeg_to_pcm16k(wav_bytes, ffmpeg)
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return _stdlib_wave_to_pcm16k(wav_bytes)
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def _ffmpeg_to_pcm16k(wav_bytes: bytes, ffmpeg: str) -> bytes:
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proc = subprocess.run(
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[
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ffmpeg,
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"-nostdin",
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"-loglevel",
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"error",
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"-i",
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"pipe:0",
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"-f",
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"s16le",
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"-ac",
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"1",
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"-ar",
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str(_BAIDU_RATE),
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"pipe:1",
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],
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input=wav_bytes,
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capture_output=True,
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timeout=120,
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check=False,
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)
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if proc.returncode != 0:
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err = (proc.stderr or b"").decode("utf-8", errors="replace")
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raise WavDecodeError(f"ffmpeg wav decode failed: {err or proc.returncode}")
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if not proc.stdout:
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raise WavDecodeError("ffmpeg produced empty PCM")
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return proc.stdout
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def _stdlib_wave_to_pcm16k(wav_bytes: bytes) -> bytes:
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try:
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with wave.open(io.BytesIO(wav_bytes), "rb") as wf:
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nchannels = wf.getnchannels()
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sampwidth = wf.getsampwidth()
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framerate = wf.getframerate()
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nframes = wf.getnframes()
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raw = wf.readframes(nframes)
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except wave.Error as exc:
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raise WavDecodeError(f"Invalid WAV: {exc}") from exc
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if sampwidth != 2:
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raise WavDecodeError(
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f"WAV sample width {sampwidth * 8} bit not supported without ffmpeg"
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)
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if nchannels not in (1, 2):
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raise WavDecodeError(
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f"WAV channels={nchannels} not supported without ffmpeg"
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)
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if framerate != _BAIDU_RATE:
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raise WavDecodeError(
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f"WAV rate {framerate} requires ffmpeg for resampling to {_BAIDU_RATE} Hz"
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)
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if nchannels == 2:
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# de-interleave stereo s16le -> mono average
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import struct
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out = bytearray()
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for i in range(0, len(raw), 4):
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chunk = raw[i : i + 4]
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if len(chunk) < 4:
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break
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l_s, r_s = struct.unpack("<hh", chunk)
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m = max(min((l_s + r_s) // 2, 32767), -32768)
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out.extend(struct.pack("<h", m))
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return bytes(out)
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return raw
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