Pyaudio 音质问题答案

【问题标题】：Pyaudio sound quality issuesPyaudio 音质问题
【发布时间】：2016-06-30 07:09:34
【问题描述】：

我有一个很好的声音波形文件，当使用 PYAUDIO 安装提供的示例 Python 程序时无法很好地播放。 使用 -aplay 播放效果很好

使用 play_wave.py 音质很好，除了背景中有很大的重复噪音（~ 6 hz）

使用 play_wave_callback.py 录音的音调显着增加，背景噪音现在更像是嗡嗡声（40-70 hz）

使用时音质不错
**aplay** -vv -D plughw:1,0 -f s16_le output.wav

有趣的是，这两个示例程序产生了截然不同的质量，而 -aplay 的声音质量很好。这可能是同一个问题。背景噪音的频率增加了大约 10 倍，声音的音调显着增加。

有什么建议吗？

更多细节：我在 2016 年 3 月下载的 Raspbian Jessie 版本的 Raspberry Pi 2 上运行这些示例程序。声音通过 USB 声卡播放。我通过删除 /boot/config.txt 中的一行来删除板载声卡

#dtparam=audio=on

aplay -l 产生

pi@raspberrypi:~ $ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 1: Set [C-Media USB Headphone Set], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
pi@raspberrypi:~ $

使用aplay音质不错，输出如下

pi@raspberrypi:~/programs $ aplay -vv -D plughw:1,0 -f s16_le output.wav
Playing WAVE 'output.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Mono
Plug PCM: Route conversion PCM (sformat=S16_LE)
  Transformation table:
    0 <- 0
    1 <- 0
Its setup is:
  stream       : PLAYBACK
  access       : RW_INTERLEAVED
  format       : S16_LE
  subformat    : STD
  channels     : 1
  rate         : 44100
  exact rate   : 44100 (44100/1)
  msbits       : 16
  buffer_size  : 22050
  period_size  : 5513
  period_time  : 125011
  tstamp_mode  : NONE
  period_step  : 1
  avail_min    : 5513
  period_event : 0
  start_threshold  : 22050
  stop_threshold   : 22050
  silence_threshold: 0
  silence_size : 0
  boundary     : 1445068800
Slave: Hardware PCM card 1 'C-Media USB Headphone Set' device 0 subdevice 0
Its setup is:
  stream       : PLAYBACK
  access       : MMAP_INTERLEAVED
  format       : S16_LE
  subformat    : STD
  channels     : 2
  rate         : 44100
  exact rate   : 44100 (44100/1)
  msbits       : 16
  buffer_size  : 22050
  period_size  : 5513
  period_time  : 125011
  tstamp_mode  : NONE
  period_step  : 1
  avail_min    : 5513
  period_event : 0
  start_threshold  : 22050
  stop_threshold   : 22050
  silence_threshold: 0
  silence_size : 0
  boundary     : 1445068800
  appl_ptr     : 0
  hw_ptr       : 0
#  +                                               | 04%
pi@raspberrypi:~/programs $

使用 play_wave.py 的声音质量很好，除了背景中有很大的重复噪音（~5-10 hz）。这是完整的代码：

"""PyAudio Example: Play a wave file."""

import pyaudio
import wave
import sys

CHUNK = 1024 * 8

#if len(sys.argv) < 2:
#    print("Plays a wave file.\n\nUsage: %s filename.wav" % sys.argv[0])
#    sys.exit(-1)

wf = wave.open('output.wav', 'rb')

# instantiate PyAudio (1)
p = pyaudio.PyAudio()

# open stream (2)
#stream = p.open(format=p.get_format_from_width(wf.getsampwidth()),
#                channels=wf.getnchannels(),
#                rate=wf.getframerate(),
#                output=True)

FORMAT = pyaudio.paInt16
CHANNELS = 1
RATE = 44100
RECORD_SECONDS = 5

stream = p.open(format=p.get_format_from_width(wf.getsampwidth()),
                channels=wf.getnchannels(),
                rate=wf.getframerate(),
                output=True)

# read data
data = wf.readframes(CHUNK)

# play stream (3)
while data != '':
    stream.write(data)
    data = wf.readframes(CHUNK)

# stop stream (4)
stream.stop_stream()
stream.close()

# close PyAudio (5)
p.terminate()

这个程序的输出是

 ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM sysdefault
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM sysdefault
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown 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 confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM surround21
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM surround21
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM surround40
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM surround41
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM surround50
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM surround51
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM surround71
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM iec958
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM spdif
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM spdif
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 confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4259:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4738:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2239:(snd_pcm_open_noupdate) Unknown PCM dmix
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


------------------
(program exited with code: 0)
Press return to continue

【问题讨论】：

标签： audio raspberry-pi raspbian pyaudio

【解决方案1】：

我不知道 PyAudio 有什么问题，但如果您想尝试不同的东西，请查看以下示例：http://python-sounddevice.readthedocs.org/en/latest/examples.html#play-a-sound-file。

这是示例的快速摘录：

import sounddevice as sd
import soundfile as sf
data, fs = sf.read('myfile.wav')
sd.play(data, fs)

这个例子需要 NumPy。如果您不想安装它，它会变得有点复杂（类似于您的 PyAudio 代码），但它仍然可以工作。

你可以安装必要的库

python3 -m pip install soundfile sounddevice

【讨论】：