""" PyAudio Example: Mac OS X-only: Play a wave file with channel maps. """

import pyaudio
import wave
import sys

chunk = 1024

PyAudio = pyaudio.PyAudio

if len(sys.argv) < 2:
    print "Plays a wave file.\n\nUsage: %s filename.wav" % sys.argv[0]
    sys.exit(-1)

wf = wave.open(sys.argv[1], 'rb')

p = PyAudio()

# standard L-R stereo
# channel_map = (0, 1)

# reverse: R-L stereo
# channel_map = (1, 0)

# no audio
# channel_map = (-1, -1)

# left channel audio --> left speaker; no right channel
# channel_map = (0, -1)

# right channel audio --> right speaker; no left channel
# channel_map = (-1, 1)

# left channel audio --> right speaker
# channel_map = (-1, 0)

# right channel audio --> left speaker
channel_map = (1, -1)
# etc...

try:
    stream_info = pyaudio.PaMacCoreStreamInfo(
        flags = pyaudio.PaMacCoreStreamInfo.paMacCorePlayNice, # default
        channel_map = channel_map)
except AttributeError:
    print "Sorry, couldn't find PaMacCoreStreamInfo. Make sure that " \
          "you're running on Mac OS X."
    import sys
    sys.exit(-1)
    
print "Stream Info Flags:", stream_info.get_flags()
print "Stream Info Channel Map:", stream_info.get_channel_map()

# open stream
stream = p.open(format =
                p.get_format_from_width(wf.getsampwidth()),
                channels = wf.getnchannels(),
                rate = wf.getframerate(),
                output = True,
                output_host_api_specific_stream_info = stream_info)

# read data
data = wf.readframes(chunk)

# play stream
while data != '':
    stream.write(data)
    data = wf.readframes(chunk)

stream.stop_stream()
stream.close()

p.terminate()