Help with sound on Fc16

[stan]

On Sun, 25 Mar 2012 12:05:41 -0700
don fisher <hdf3 at comcast.net> wrote:

> Thanks. After a reboot, it started working for an as yet unknown
> reason.

Perversity!  ;-)

> With my home audio system, I can debug things with a signal generator 
> starting at the speaker and working back to the source until I find 
> where the problem is. Is there a way to do similar debugging with
> pulse audio and alsa? I would like to inject signals at the sound
> card, the back if I knew what the input were. It is easier with RCA
> hacks. USB inputs are still beyond my test set:-) (maybe a USB DVD
> player?).

I'm not completely clear what you want to do here.  I think you want to
treat a software path like a hardware path.  The most basic is to
maximize logging from sound applications.  Or you could compile
alsa-lib with debugging turned on and trace what happens when sound is
sent through it using gdb.  Or you could run a sound playing
application with strace.  In a GUI, most things are event driven, so
the paths periodically exist and don't exist.  I don't think it is
possible to do what you want in the way you mean.