Pyaudio：如何压缩音频流

我目前正在 python 中开发一个 VOIP 工具，作为客户端服务器工作，如下所示：

CHUNK = 1024
p = pyaudio.PyAudio()
stream = p.open(format = pyaudio.paInt16,
        channels = 1,
        rate = 44100,
        input = True,
        frames_per_buffer = CHUNK)

while 1:
    connection.sendVoice(stream.read(CHUNK))

我怎样才能继续压缩发送的数据以备用连接，也许可以提高速度，...

import time, sys,io
import pymedia.audio.sound as sound
import pymedia.audio.acodec as acodec
import pymedia.muxer as muxer


def voiceRecorder( secs, name ):
  f = open(name,'wb')
  secs = secs*5
  dm= muxer.Demuxer('mp3')
  snds= sound.getODevices()
  rt = 44100
  cparams= { 'id': acodec.getCodecID( 'mp3' ),
             'bitrate': 128000/4,
             'sample_rate': rt,
             'channels': 2 } 
  ac= acodec.Encoder( cparams )
  snd= sound.Input( rt, 2, sound.AFMT_S16_LE )
  snd.start()
  start_time = time.time()

  while snd.getPosition()<= secs:

   s= snd.getData()
   if s and len( s ):

     for fr in ac.encode( s ):
       f.write( fr)

    else:
      time.sleep(.25)



  snd.stop()


if __name__ == "__main__":
  if len( sys.argv )!= 3:
    print 'Usage: voice_recorder <seconds> <file_name>'
  else:
    voiceRecorder( int( sys.argv[ 1 ] ), sys.argv[ 2 ]  )