Question

由于在老帖子或其他论坛中我都找不到答案，因此我想向stackoverflow社区寻求建议。

我正在使用树莓派，版本9（拉伸），内核版本为4.14.71-v7。它应该是最新的可用图像。

我想用pyaudio播放和录制音频流。在我的Windows家用PC上，一切正常，没有任何问题。但是，即使在树莓派上创建pyaudio对象也会引发一些奇怪的警告。

首先，我安装了以下东西以使用pyaudio：

    sudo apt-get install libasound-dev

raspberry pi自动选择libasound2-dev

    sudo apt-get install portaudio19-dev
    sudo apt-get install python3-pyaudio

如果我运行以下python代码：

   import pyaudio
   py=pyaudio.PyAudio()

我收到这些警告：

   '$'ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'cards.bcm2835_alsa.pcm.front.0:CARD=0'
   '$'ALSA lib conf.c:4528:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
   '$'ALSA lib conf.c:5007:(snd_config_expand) Evaluate error: No such file or directory
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM front
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side
   '$'ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'cards.bcm2835_alsa.pcm.surround51.0:CARD=0'
   '$'ALSA lib conf.c:4528:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
   '$'ALSA lib conf.c:5007:(snd_config_expand) Evaluate error: No such file or directory
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM surround21
   '$'ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'cards.bcm2835_alsa.pcm.surround51.0:CARD=0'
   '$'ALSA lib conf.c:4528:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
   '$'ALSA lib conf.c:5007:(snd_config_expand) Evaluate error: No such file or directory
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM surround21
   '$'ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'cards.bcm2835_alsa.pcm.surround40.0:CARD=0'
   '$'ALSA lib conf.c:4528:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
   '$'ALSA lib conf.c:5007:(snd_config_expand) Evaluate error: No such file or directory
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM surround40
   '$'ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'cards.bcm2835_alsa.pcm.surround51.0:CARD=0'
   '$'ALSA lib conf.c:4528:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
   '$'ALSA lib conf.c:5007:(snd_config_expand) Evaluate error: No such file or directory
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM surround41
   '$'ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'cards.bcm2835_alsa.pcm.surround51.0:CARD=0'
   '$'ALSA lib conf.c:4528:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
   '$'ALSA lib conf.c:5007:(snd_config_expand) Evaluate error: No such file or directory
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM surround50
   '$'ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'cards.bcm2835_alsa.pcm.surround51.0:CARD=0'
   '$'ALSA lib conf.c:4528:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
   '$'ALSA lib conf.c:5007:(snd_config_expand) Evaluate error: No such file or directory
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM surround51
   '$'ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'cards.bcm2835_alsa.pcm.surround71.0:CARD=0'
   '$'ALSA lib conf.c:4528:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
   '$'ALSA lib conf.c:5007:(snd_config_expand) Evaluate error: No such file or directory
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM surround71
   '$'ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'cards.bcm2835_alsa.pcm.iec958.0:CARD=0,AES0=4,AES1=130,AES2                    =0,AES3=2'
   '$'ALSA lib conf.c:4528:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
   '$'ALSA lib conf.c:5007:(snd_config_expand) Evaluate error: No such file or directory
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM iec958
   '$'ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'cards.bcm2835_alsa.pcm.iec958.0:CARD=0,AES0=4,AES1=130,AES2                    =0,AES3=2'
   '$'ALSA lib conf.c:4528:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
   '$'ALSA lib conf.c:5007:(snd_config_expand) Evaluate error: No such file or directory
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM spdif
   '$'ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'cards.bcm2835_alsa.pcm.iec958.0:CARD=0,AES0=4,AES1=130,AES2                    =0,AES3=2'
   '$'ALSA lib conf.c:4528:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
   '$'ALSA lib conf.c:5007:(snd_config_expand) Evaluate error: No such file or directory
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM spdif
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline
   '$'ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'defaults.bluealsa.device'
   '$'ALSA lib conf.c:4528:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
   '$'ALSA lib conf.c:4996:(snd_config_expand) Args evaluate error: No such file or directory
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM bluealsa
   '$'ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'defaults.bluealsa.device'
   '$'ALSA lib conf.c:4528:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
   '$'ALSA lib conf.c:4996:(snd_config_expand) Args evaluate error: No such file or directory
   '$'ALSA lib pcm.c:2495:(snd_pcm_open_noupdate) Unknown PCM bluealsa
   '$'connect(2) call to /tmp/jack-1000/default/jack_0 failed (err=No such file or directory)
   '$'attempt to connect to server failed

对我来说，pyaudio似乎想使用HDMI（带有环绕声），插孔和蓝牙（bluealsa）。似乎pyaudio不使用portaudio。但是我不确定。

也许有人知道，为什么仅创建对象会引发这些警告。在这些警告旁边，pyaudio库似乎可以正常工作。我可以播放并记录音频流，但是这些警告每次都会出现。

Answer 1

感谢stackoverflow社区。我有一个旧主题的链接，它提供了理想的解决方案。

主题名称：“ PyAudio正常工作，但每次都会吐出错误消息”

解释了所有这些警告发生的原因以及如何使用python处理它们。

非常感谢！

PyAudio在Raspberry Pi上发出警告

1 个答案: