[pulseaudio-discuss] KMD Wireless Talkback Pro problems

[Tanu Kaskinen]

On Wed, 2014-08-27 at 17:41 +0600, Alexander E. Patrakov wrote:
> 27.08.2014 17:18, Bráulio Bhavamitra wrote:
> > Hello Alexander,
> >
> > I thought all my apps were using pulseaudio. I use mainly skype, mplayer
> > and amarok.
> >
> > How can I double check if there is another app not using pulseaudio?
> 
> I can suggest two very rough tests. However, as restarting PulseAudio 
> helps, I doubt that they will find anything, because you need to test 
> that at the time PulseAudio starts.
> 
> 1. Start pavucontrol. Make sure that your app plays a sound. Look into 
> the pavucontrol window and see if you can see the stream on the first 
> tab. If you can, then the app is definitely using PulseAudio.
> 
> 2. Start a terminal. Make sure that your app plays a sound. While it is 
> playing, run this command in the terminal:
> 
> fuser -v /dev/snd/pcm*
> 
> If it prints anything that is not about pulseaudio, then that app uses 
> ALSA directly in a way incompatible with PulseAudio.
> 
> Tanu: would a linux-specific patch be welcome that attempts to log which 
> process keeps the device open?

Yes, I like that idea.

> If so - should I walk /proc myself, or 
> defer to fuser?

I'd prefer to not call external programs. I suppose we want the log
message to appear immediately after we have noticed that a sound card is
busy, so the fuser call would have to be synchronous. Perhaps I
overestimate the difficulty, but it might not be any simpler to run
fuser, read its stdout and wait for its exit while blocking the main
thread, than to parse /proc yourself.

-- 
Tanu