First version

This commit is contained in:
Fabio Manganiello 2020-11-02 13:08:18 +01:00
parent 58fae0fb71
commit d1261a6a05
5 changed files with 230 additions and 0 deletions

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# micstream
Stream an audio input device over HTTP as mp3
## Requirements
`ffmpeg` and `lame` installed on the system, e.g.:
```bash
[sudo] apt-get install ffmpeg lame
```

5
micstream/__init__.py Normal file
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from micstream.audio import AudioSource
from micstream.server import Server
# vim:sw=4:ts=4:et:

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micstream/__main__.py Normal file
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import logging
import sys
from micstream import AudioSource, Server
def init_logging():
logging.basicConfig(level=logging.INFO,
stream=sys.stdout,
format='[%(asctime)s] %(name)s|%(levelname)-8s|%(message)s',
datefmt='%Y-%m-%d %H:%M:%S')
def main():
init_logging()
with AudioSource('plughw:3,0') as source, \
Server() as server:
for sample in source:
server.process_audio(sample)
if __name__ == '__main__':
main()
# vim:sw=4:ts=4:et:

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

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micstream/server.py Normal file
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import logging
import threading
from queue import Queue
from typing import Callable, Dict
from flask import Flask, Response
class Endpoint:
def __init__(self, action):
self.action = action
def __call__(self, *args, **kwargs):
return Response(self.action(*args, **kwargs), status=200, headers={})
class Server:
def __init__(self,
host: str = '0.0.0.0',
port: int = 8080,
endpoint: str = '/stream.mp3',
debug: bool = False):
self.host = host
self.port = port
self.debug = debug
self.endpoint = endpoint
self.app = Flask(__name__)
self.logger = logging.getLogger(self.__class__.__name__)
self.logger.setLevel(logging.DEBUG if self.debug else logging.INFO)
self._audio_lock = threading.RLock()
self._stream_queues: Dict[int, Queue] = {}
self._next_queue_id = 1
self.add_endpoints()
self.thread = threading.Thread(target=self.app.run,
kwargs=dict(host=self.host, port=self.port,
debug=debug, use_reloader=False))
def __enter__(self):
self.thread.start()
return self
def __exit__(self, exc_type, exc_val, exc_tb):
pass # TODO find a clean way to get Flask to stop
def process_audio(self, audio: bytes):
with self._audio_lock:
for q in self._stream_queues.values():
q.put(audio)
def add_endpoints(self):
self.add_endpoint(self.endpoint, self.stream())
def add_endpoint(self, endpoint: str, handler: Callable):
self.app.add_url_rule(endpoint, endpoint, handler)
def _get_feed(self):
with self._audio_lock:
queue_id = self._next_queue_id
self._stream_queues[queue_id] = Queue()
self._next_queue_id += 1
q = self._stream_queues[queue_id]
try:
while True:
audio = q.get()
if not audio:
continue
self.logger.debug('Got audio sample of length {}'.format(len(audio)))
yield audio
finally:
with self._audio_lock:
del self._stream_queues[queue_id]
def stream(self):
def endpoint():
return Response(self._get_feed(),
mimetype='audio/mpeg')
return endpoint
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