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[英]pyaudio OSError: [Errno -9998] Invalid number of channels (On mac with External sound card)
[英]Getting IOError: [Errno Invalid number of channels] -9998 when using mic with PyAudio on Raspberry Pi
坏消息,大家!
我尝试通过PyAudio在Raspberry Pi上使用麦克风,但没有成功。 麦克风已连接到USB声卡。
当我通过“ arecord”时,麦克风起作用:
pi@raspberrypi ~ $ arecord -D plughw:0,0 -f cd test2.wav
Recording WAVE 'test2.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
但是,当我在PyAudio中执行test record.py测试时,出现错误。 对于使用PyAudio的Python中的所有程序,该错误相同:
pi@raspberrypi /usr/src/pyaudio/test $ python record.py
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline
ALSA lib pcm_dmix.c:957:(snd_pcm_dmix_open) The dmix plugin supports only playback stream
Expression 'parameters->channelCount <= maxChans' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 1438
Expression 'ValidateParameters( inputParameters, hostApi, StreamDirection_In )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2742
Traceback (most recent call last):
File "record.py", line 26, in <module>
frames_per_buffer=CHUNK)
File "/usr/local/lib/python2.7/dist-packages/pyaudio.py", line 747, in open
stream = Stream(self, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/pyaudio.py", line 442, in __init__
self._stream = pa.open(**arguments)
IOError: [Errno Invalid number of channels] -9998
谢谢你的帮助
您是否在Raspberry PI上连接了声卡? 默认情况下,您获得音频输出,但没有音频输入。 您可以通过运行检查
alsamixer
如果按F6
键,您应该会看到声卡已列出。 如果按F4
键,您应该会看到捕获设备(如果有)
我使用eBay的廉价USB声卡进行测试。
声卡带有音频输入后,请确保将pyaudio配置为使用正确的声卡索引和声道数(我的声道是单声道音频输入,不是立体声)。
pyaudio.PyAudio().open(format=pyaudio.paInt16,
rate=44100,
channels=1, #change this to what your sound card supports
input_device_index=1, #change this your input sound card index
input=True,
output=False,
frames_per_buffer=1024)
您可以使用pyaudio.PyAudio的实例方法get_device_count
和get_device_info_by_index
来获取索引。
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