record.py

   1 #!/usr/bin/python3
   2 """
   3 PyAudio example: Record a few seconds of audio and save to a WAVE
   4 file.
   5 """
   6
   7 import json
   8 import sys
   9 import wave
  10
  11 import pyaudio
  12
  13 PARAMFILE = '/var/lib/ampy/params.json'
  14 CHUNK = 1024
  15 FORMAT = pyaudio.paInt16
  16 CHANNELS = 2
  17 RATE = 44100
  18 RECORD_SECONDS = 5
  19 WAVE_OUTPUT_FILENAME = "/tmp/output.wav"
  20
  21 if sys.platform == 'darwin':
  22     CHANNELS = 1
  23
  24 p = pyaudio.PyAudio()
  25
  26 try:
  27     with open(PARAMFILE) as f:
  28         params = json.loads(f.read())
  29         alsadevice = params['alsadevice']
  30 except (FileNotFoundError, json.decoder.JSONDecodeError, KeyError):
  31     print("Error reading the parameters. Please run device.py")
  32
  33 stream = p.open(format=FORMAT,
  34                 channels=CHANNELS,
  35                 rate=RATE,
  36                 input=True,
  37                 input_device_index=alsadevice,
  38                 frames_per_buffer=CHUNK)
  39
  40 print("* recording to", WAVE_OUTPUT_FILENAME)
  41
  42 frames = []
  43
  44 for i in range(0, int(RATE / CHUNK * RECORD_SECONDS)):
  45     data = stream.read(CHUNK, exception_on_overflow=False)
  46     frames.append(data)
  47
  48 print("* done recording")
  49
  50 stream.stop_stream()
  51 stream.close()
  52 p.terminate()
  53
  54 wf = wave.open(WAVE_OUTPUT_FILENAME, 'wb')
  55 wf.setnchannels(CHANNELS)
  56 wf.setsampwidth(p.get_sample_size(FORMAT))
  57 wf.setframerate(RATE)
  58 wf.writeframes(b''.join(frames))
  59 wf.close()