[Portaudio] ALSA and Miscellaneous Errors

Alan Horstmann gineera at aspect135.co.uk
Sat Mar 24 08:14:34 EDT 2012


On Saturday 24 March 2012 05:37, Michael Reutman wrote:
> Hello all,
> Just downloaded portaudio and have compiled a few of the examples. So far,
> the examples I have tried produce sound, but generate a few erros which I
> would like to resolve so they aren't always appearing whenever I compile my
> code. Here is what I am generating in terminal....

Please give exact Portaudio version, and Alsa driver and lib versions.

> PortAudio Test: output sawtooth wave.
> ALSA lib pcm.c:2212:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
> ALSA lib pcm.c:2212:(snd_pcm_open_noupdate) Unknown PCM
> cards.pcm.center_lfe
> ALSA lib pcm.c:2212:(snd_pcm_open_noupdate) Unknown 
> PCM cards.pcm.side ALSA lib

These are harmless, and come from the Alsa config; In particular there are 
pcms listed in alsa.conf that are not implemented in the card specific config 
file.  Portaudio is simply reporting these inconsistencies when initializing. 

> audio/pcm_bluetooth.c:1613:(audioservice_expect) BT_GET_CAPABILITIES failed
> : Input/output error(5) ALSA lib
> audio/pcm_bluetooth.c:1613:(audioservice_expect) BT_GET_CAPABILITIES failed
> : Input/output error(5) ALSA lib
> audio/pcm_bluetooth.c:1613:(audioservice_expect) BT_GET_CAPABILITIES failed
> : Input/output error(5) ALSA lib
> audio/pcm_bluetooth.c:1613:(audioservice_expect) BT_GET_CAPABILITIES failed

Some part of the bluetooth config is not working either.

> : Input/output error(5) ALSA lib pcm_dmix.c:957:(snd_pcm_dmix_open) The
> dmix plugin supports only playback stream 

That should be gone in latest Portaudio code.

> Cannot connect to server socket 
> err = No such file or directory
> Cannot connect to server socket
> jack server is not running or cannot be started
> Test finished.

..

> I believe my plan of attack is to just set it for device 12. This may be
> somewhere in the documentation, but it is rather late at the moment and I'm
> developing quite the headache, so I figured I would bounce it off some of
> you profesionals.  Thanks in advance,

The Alsa 'default' device would normally be used by Portaudio, if 
defaultOutputDevice is specified.

Bear in mind that during initialize, Portaudio probes any pcm devices that are 
listed in the Alsa configuration, but those may be broken, non-functional, or 
absent.  It attempts to open each, so that it can give a list of devices with 
a reasonable likely-hood of working.  In doing so, it does provoke messages 
from the underlying Alsa layers.

There is a Portaudio ticket regarding undesirable warnings, but it would be 
inappropriate to just mask all of these since they give clues in the event of 
mis-behaviour.  So perhaps just shut your eyes???

Regards

Alan





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