Getting BBB working with pyAudio and USB Audio card

[jma...@gmail.com]

I'm trying to get pyAudio operational with a C-media mic/speaker card on a beaglebone black running ubuntu 13.04.

After many permutations of attempts, I'm seeking help here - as I simply cannot get the combination of configuration and pyAudio to play nice here.

I've disabled the HDMI by modifying uEnv.txt: optargs=quiet capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN

And I see my sound card listed:

root@ubuntu-armhf:/home/ubuntu# cat /proc/asound/devices 

  2: [ 1- 0]: digital audio playback

  3: [ 1- 0]: digital audio capture

  4: [ 1]   : control

 33:        : timer

and:

root@ubuntu-armhf:/home/ubuntu# 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

Simple python code fails:

import pyaudio

p=pyaudio.PyAudio()

s=p.open(format=pyaudio.paInt16,input_device_index=1,channels=1,rate=44100,input=True,frames_per_buffer=1024)

with the following errors:

root@ubuntu-armhf:/home/ubuntu# python audio_test.py 

ALSA lib confmisc.c:768:(parse_card) cannot find card '0'

ALSA lib conf.c:4241:(_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:4241:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory

Attempts to change the default card to '0' have failed as well. 2 Examples:

1. Per: http://ubuntuforums.org/showthread.php?t=1313071, adding

root@ubuntu-armhf:/etc/modprobe.d# tail -1 alsa-base.conf 

options snd-card-usb-caiaq index=0

does not seem to set the default card to 0 (this is the setting used above)

2. Changing asound.conf per: http://feipengy.no-ip.biz/blog/2013/12/09/enable-audio-in-beaglebone-black/

Similar failure is observed from pyAudio.

Any ideas? I suspect I'm missing something really obvious here.

[andima...@gmail.com]

I don't know why this traceback is printed, but it does not seem to affect performance. Try to use the soundcard dispite the traceback.