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python - 在 Raspberry Pi 4 上无法使用 PyAudio 获得音频输出

问题描述

这里有点不知所措。目前，下面的代码不能正常播放 wav 文件。我添加了一些打印语句，发现while循环永远不会结束。

我正在使用 Raspberry Pi 4。我使用...安装了 PyAudio

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

奇怪的是录音作品。此外，使用aplay soundfile.wav也有效。

def play(fileName):
    CHUNK = 1024

    wf = wave.open(fileName, 'rb')

    p = pyaudio.PyAudio()

    stream = p.open(format=p.get_format_from_width(wf.getsampwidth()),
                    channels=2,
                    rate=wf.getframerate(),
                    output=True,
                    output_device_index=0)
  
    data = wf.readframes(CHUNK)

    print("starting loop")

    while len(data) > 0: # also tried: while data != ''
        stream.write(data)
        data = wf.readframes(CHUNK)

    print("finished loop")

    stream.stop_stream()
    stream.close()

    p.terminate()
        
play("soundfile.wav")

上面的代码导致以下消息。

Expression 'alsa_snd_pcm_hw_params_set_period_size_near( pcm, hwParams, &alsaPeriodFrames, &dir )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 924
Expression 'alsa_snd_pcm_hw_params_set_period_size_near( pcm, hwParams, &alsaPeriodFrames, &dir )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 924
ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'defaults.pcm.dsnoop.device'
ALSA lib conf.c:4568:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:5047:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2565:(snd_pcm_open_noupdate) Unknown PCM sysdefault
ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'defaults.pcm.dsnoop.device'
ALSA lib conf.c:4568:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:5047:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2565:(snd_pcm_open_noupdate) Unknown PCM sysdefault
ALSA lib pcm.c:2565:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.iec958
ALSA lib pcm.c:2565:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.iec958
ALSA lib pcm.c:2565:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.iec958
ALSA lib pcm.c:2565:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi
ALSA lib pcm.c:2565:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi
ALSA lib confmisc.c:1281:(snd_func_refer) Unable to find definition 'defaults.bluealsa.device'
ALSA lib conf.c:4568:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:5036:(snd_config_expand) Args evaluate error: No such file or directory
ALSA lib pcm.c:2565:(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:4568:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:5036:(snd_config_expand) Args evaluate error: No such file or directory
ALSA lib pcm.c:2565:(snd_pcm_open_noupdate) Unknown PCM bluealsa
Expression 'alsa_snd_pcm_hw_params_set_period_size_near( pcm, hwParams, &alsaPeriodFrames, &dir )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 924
ALSA lib pcm.c:2565:(snd_pcm_open_noupdate) Unknown PCM input
Expression 'alsa_snd_pcm_hw_params_set_period_size_near( pcm, hwParams, &alsaPeriodFrames, &dir )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 924
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock

starting loop

如果有人对可能是什么问题有任何见解，我将不胜感激。

标签： pythonraspberry-pipyaudioalsaraspberry-pi4

解决方案

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