在 Ubuntu 14.04 上使用 python 读取音频时出错

Question

When running the following code using python 2.7 (in Ubuntu 14.04)

import pyaudio
p = pyaudio.PyAudio()

I get the following exception:

ALSA lib pcm_dsnoop.c:618:(snd_pcm_dsnoop_open) unable to open slave

ALSA lib pcm_dmix.c:1022:(snd_pcm_dmix_open) unable to open slave

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

bt_audio_service_open: connect() failed: Connection refused (111)

bt_audio_service_open: connect() failed: Connection refused (111)

bt_audio_service_open: connect() failed: Connection refused (111)

bt_audio_service_open: connect() failed: Connection refused (111)

ALSA lib pcm_dmix.c:1022:(snd_pcm_dmix_open) unable to open slave

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

Your help would be highly appreciated

Answer 1

Do you have bluez-alsa package installed? If so remove it, and re-test. Should get rid of the errors.

If not there is also some discussion here ( https://github.com/Katee/quietnet/issues/18 ) that might be helpful.

ALSA lib pcm.c:7843:(snd_pcm_recover) underrun occurred

The underun is likely caused because pulseaudio is already accessing 
the card - you can pause it using http://linux.die.net/man/1
/pasuspender. In general to avoid such deadlock, you need a 
soundserver like jackd https://help.ubuntu.com/community/What%20is%20JACK, but you already figured this out from the following log
entries in your trace ;-) (apt-get install jackd)