Question

我需要使用python在我的覆盆子pi上生成声音，我只需要生成特定频率的正弦波。我试图使用PyAudio和下面的代码（我在这里找到https://mail.python.org/pipermail/tutor/2012-September/091476.html）

来做到这一点

import math
import struct
import pyaudio

def play_tone(frequency, amplitude, duration, fs, stream):
    N = int(fs / frequency)
    T = int(frequency * duration)  # repeat for T cycles
    dt = 1.0 / fs
    # 1 cycle
    tone = (amplitude * math.sin(2 * math.pi * frequency * n * dt)
            for n in xrange(N))
    # todo: get the format from the stream; this assumes Float32
    data = ''.join(struct.pack('f', samp) for samp in tone)
    for n in xrange(T):
        stream.write(data)

fs = 48000
p = pyaudio.PyAudio()
stream = p.open(
    format=pyaudio.paFloat32,
    channels=1,
    rate=fs,
    output=True)

# play the C major scale
scale = [130.8, 146.8, 164.8, 174.6, 195.0, 220.0, 246.9, 261.6]
for tone in scale:
    play_tone(tone, 0.5, 0.75, fs, stream)

# up an octave
for tone in scale[1:]:
    play_tone(2*tone, 0.5, 0.75, fs, stream)

stream.close()
p.terminate()

这在我的电脑上完全正常，但在Raspberry Pi上没有。当我在Raspberry Pi上运行代码时声音非常恶劣，我收到以下错误：

ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.front
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround21
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround21
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround40
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround41
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround50
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround51
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround71
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.iec958
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.iec958
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.iec958
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline
ALSA lib pulse.c:243:(pulse_connect) PulseAudio: Unable to connect: Connection refused

ALSA lib pulse.c:243:(pulse_connect) PulseAudio: Unable to connect: Connection refused

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

我已经花了很长时间试图用我在互联网上找到的信息解决这个问题，但无济于事。

不幸的是，我对此很新，并且不知道我在做什么，所以如果这篇文章太不明确我很抱歉，我会尽力澄清任何必要的事情。

使用PyAudio在Raspberry Pi上生成音频会导致音频断断续续

0 个答案: