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由于我在较早的帖子和其他论坛中都找不到我的问题的答案，因此我想向 stackoverflow 社区寻求建议。

我正在使用带有内核版本 4.14.71-v7 的树莓派版本 9（拉伸）。它应该是可用的最新图像。

我想使用 pyaudio 来播放和录制音频流。在我的 Windows 家用电脑上，一切正常，没有任何问题。但即使在树莓派上创建一个 pyaudio 对象也会引发一些奇怪的警告。

首先，我安装了以下东西来使用 pyaudio：

    sudo apt-get install libasound-dev

树莓派自动选择 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，看起来 pyaudio 想要使用 hdmi（带有环绕声）、插孔和蓝牙（bluealsa）。似乎pyaudio不使用portaudio。但我不确定。

也许有人知道，为什么只创建一个对象就会引发这些警告。在这些警告旁边，pyaudio 库似乎可以工作。我可以播放和录制音频流，但每次都会出现这些警告。

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1 回答 1

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感谢 stackoverflow 社区。我得到了一个旧主题的链接，它提供了完美的解决方案。

  • 主题名称：“PyAudio 工作，但每次都吐出错误消息”

解释了所有这些警告出现的原因以及如何使用 python 处理它们。

太谢谢了！！！

于 2018-11-03T09:46:11.183 回答