65 lines
2.0 KiB
Python
65 lines
2.0 KiB
Python
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"""Audio alarm functions — WAV loading and PCM streaming."""
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import asyncio
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import json
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import logging
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import wave
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from pathlib import Path
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log = logging.getLogger(__name__)
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CHUNK_SIZE = 4096
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AUDIO_DIR = Path(__file__).parent / "assets" / "alarm"
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def find_wav() -> Path:
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"""Find the first .wav file in the alarm assets directory."""
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wavs = list(AUDIO_DIR.glob("*.wav"))
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if not wavs:
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raise FileNotFoundError(f"No .wav files found in {AUDIO_DIR}")
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log.info("Using audio file: %s", wavs[0].name)
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return wavs[0]
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def read_wav(path: Path) -> tuple[bytes, int, int, int]:
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"""Read WAV file and return (pcm_data, sample_rate, channels, bits_per_sample)."""
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with wave.open(str(path), "rb") as wf:
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sr = wf.getframerate()
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ch = wf.getnchannels()
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bits = wf.getsampwidth() * 8
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pcm = wf.readframes(wf.getnframes())
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log.info("WAV loaded: %dHz %dch %dbit, %.1fs, %d bytes",
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sr, ch, bits, len(pcm) / (sr * ch * (bits // 8)), len(pcm))
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return pcm, sr, ch, bits
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def chunk_bytes(data: bytes, size: int):
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"""Yield data in fixed-size chunks."""
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for i in range(0, len(data), size):
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yield data[i : i + size]
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async def stream_alarm(ws, pcm: bytes, sr: int, ch: int, bits: int):
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"""Stream one alarm cycle to the connected client."""
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bytes_per_sec = sr * ch * (bits // 8)
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chunk_duration = CHUNK_SIZE / bytes_per_sec
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pace_delay = chunk_duration * 0.9 # 90% real-time to avoid underrun
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total_chunks = (len(pcm) + CHUNK_SIZE - 1) // CHUNK_SIZE
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start_msg = json.dumps({
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"type": "alarm_start",
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"sample_rate": sr,
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"channels": ch,
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"bits": bits,
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})
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await ws.send(start_msg)
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log.info("Sent alarm_start (%d chunks, pace %.1fms)", total_chunks, pace_delay * 1000)
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for i, chunk in enumerate(chunk_bytes(pcm, CHUNK_SIZE)):
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await ws.send(chunk)
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await asyncio.sleep(pace_delay)
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await ws.send(json.dumps({"type": "alarm_stop"}))
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log.info("Sent alarm_stop")
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