Question

坏消息，大家好！

我尝试通过PyAudio在我的Raspberry Pi上使用麦克风，但没有成功。麦克风连接到USB声卡。

麦克风在我通过＆＃39; arecord＆＃39; ：

pi@raspberrypi ~ $ arecord -D plughw:0,0 -f cd test2.wav
Recording WAVE 'test2.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo

然而，当我在PyAudio中进行测试record.py时，我收到了一个错误。 Python中使用PyAudio的所有程序的错误都是相同的：

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

感谢您的帮助

Answer 1

Raspberry PI附有声卡吗？默认情况下，您可以获得音频输出，但不能输入音频。您可以通过运行

进行检查

alsamixer

如果按F6，您应该会看到列出的声卡。如果按F4，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。

有声卡输入声卡后，请确保配置pyaudio以使用正确的声卡索引和声道数量（我的是单声道音频输入，而不是立体声）。

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。

在Raspberry Pi上使用带有PyAudio的麦克风时获取IOError：[Errno无效通道数] -9998

1 个答案: