103 lines
3.0 KiB
Python
103 lines
3.0 KiB
Python
import logging
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import os
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import signal
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import subprocess
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import sys
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import time
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class AudioSource:
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def __init__(self,
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device: str,
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audio_system: str = 'alsa',
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sample_rate: int = 44100,
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bitrate: int = 128,
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channels: int = 1,
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ffmpeg_bin: str = 'ffmpeg',
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bufsize: int = 8192,
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debug: bool = False):
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self.ffmpeg_bin = ffmpeg_bin
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self.debug = debug
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self.bufsize = bufsize
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self.devnull = None
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self.ffmpeg = None
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self.logger = logging.getLogger(self.__class__.__name__)
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self.logger.setLevel(logging.DEBUG if self.debug else logging.INFO)
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self.ffmpeg_args = (
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ffmpeg_bin, '-f', audio_system, '-i', device, '-vn', '-acodec', 'libmp3lame',
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'-b:a', str(bitrate) + 'k', '-ac', str(channels), '-ar', str(sample_rate),
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'-f', 'mp3', '-')
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self._ffmpeg_start_time = None
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self._first_sample_time = None
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self.latency = 0.
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def __iter__(self):
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return self
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def __next__(self) -> bytes:
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if not self.ffmpeg or self.ffmpeg.poll() is not None:
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raise StopIteration
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while True:
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data = self.ffmpeg.stdout.read(self.bufsize)
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if not data:
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break
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if not self._first_sample_time:
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self._first_sample_time = time.time()
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self.latency = self._first_sample_time - self._ffmpeg_start_time
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self.logger.info('Estimated latency: {} msec'.format(int(self.latency * 1000)))
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if time.time() - self._first_sample_time >= self.latency:
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return data
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raise StopIteration
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def __enter__(self):
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kwargs = dict(stdout=subprocess.PIPE)
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if not self.debug:
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self.devnull = open(os.devnull, 'w')
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kwargs['stderr'] = self.devnull
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self.logger.info('Running FFmpeg: {}'.format(' '.join(self.ffmpeg_args)))
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self.ffmpeg = subprocess.Popen(self.ffmpeg_args, **kwargs)
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self._ffmpeg_start_time = time.time()
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return self
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def __exit__(self, exc_type, exc_val, exc_tb):
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if self.ffmpeg:
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self.ffmpeg.terminate()
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try:
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self.ffmpeg.wait(timeout=5)
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except subprocess.TimeoutExpired:
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self.logger.warning('FFmpeg process termination timeout')
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if self.ffmpeg.poll() is None:
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self.ffmpeg.kill()
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self.ffmpeg.wait()
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self.ffmpeg = None
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if self.devnull:
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self.devnull.close()
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self.devnull = None
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self._ffmpeg_start_time = None
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self._first_sample_time = None
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def pause(self):
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if not self.ffmpeg:
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return
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self.ffmpeg.send_signal(signal.SIGSTOP)
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def resume(self):
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if not self.ffmpeg:
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return
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self.ffmpeg.send_signal(signal.SIGCONT)
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# vim:sw=4:ts=4:et:
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