sounddevi多输入输出通道接线

Question

我试图使输入输出对的sounddevice模块上的Raspberry Pi与4 USB声卡。我做了两个有线频道，但不断失败，从三个。理想情况下，我想建立多达4个通道的真实流（延迟并不重要。）

我使用回调和：，它似乎可以正常工作，最多两个频道。请查找以下代码：

import sounddevice as sd

def wirecall(indata,outdata,*stuff):
    #sd.CallbackStop()
    outdata[:]=indata

with sd.Stream(device=0,channels=1,callback=wirecall,samplerate=44100):
    with sd.Stream(device=1, channels=1, callback=wirecall, samplerate=44100):
        while True:
                response=input()
                if response in ('', 'q', 'Q'):
                    break

这很管用，但我再加上一个：它不管用。这是Raspberry还是Sounddevice模块的限制？我也尝试了PyAudio，但结果相同

当我试图打开下面的错误消息发生3流

>>> with sd.Stream(device=3,channels=1,callback=wirecall,samplerate=44100):
...     with sd.Stream(device=1,channels=1,callback=wirecall,samplerate=44100):
...         with sd.Stream(device=2, channels=1,callback=wirecall,samplerate=44100):
...             while True:
...                 response=input()
...                 if response in ('', 'q', 'Q'):
...                     break
...
Traceback (most recent call last):
  File "<stdin>", line 3, in <module>
  File "/home/pi/.local/lib/python2.7/site-packages/sounddevice.py", line 1662, in __init__
    **_remove_self(locals()))
  File "/home/pi/.local/lib/python2.7/site-packages/sounddevice.py", line 780, in __init__
    'Error opening {0}'.format(self.__class__.__name__))
  File "/home/pi/.local/lib/python2.7/site-packages/sounddevice.py", line 2570, in _check
    raise PortAudioError(errormsg, err, hosterror_info)
sounddevice.PortAudioError: Error opening Stream: Unanticipated host error [PaErrorCode -9999]: 'Broken pipe' [ALSA error -32]
>>>