How to programmatically test whether sound is playing?

Atticus · **Joined:** Mon Mar 03, 2008 7:02 pm **Posts:** 227

hey all,

I'm attempting to modify a small C program to test for whether or not sound is playing. The behavior of the function I'm looking for is that it would query the system somehow, then if the system is playing sounds (ie, music) then it would return 1, or 0 otherwise.

I'm a C novice and a linux novice as well, so I'm not really sure how to do this or where to start. I'm guessing that I should look in the /proc directory, or possibly something like /dev/dsp?

Thanks for helping!

gapan · **Posted:** Sat Apr 12, 2008 11:23 pm

I think you can play with what's under /dev/snd, /dev/dsp and lsof. In my system if audacious is playing through alsa I can do:

Code:

george[~]$ lsof /dev/snd/pcmC0D0p 
COMMAND    PID   USER   FD   TYPE DEVICE SIZE NODE NAME
audacious 1579 george  mem    CHR  116,5      6240 /dev/snd/pcmC0D0p
audacious 1579 george   12u   CHR  116,5      6240 /dev/snd/pcmC0D0p

and if it's playing through the included OSS driver in audacious-crossfader I get

Code:

george[~]$ lsof /dev/dsp 
COMMAND    PID   USER   FD   TYPE DEVICE SIZE NODE NAME
audacious 1654 george   11u   CHR   14,3      7372 /dev/sound/dsp

Atticus · **Joined:** Mon Mar 03, 2008 7:02 pm **Posts:** 227

ah nice! That seems to work for me too, I'll see what I can do with it.

Atticus · **Joined:** Mon Mar 03, 2008 7:02 pm **Posts:** 227

I've done i!

I patched xautolock to check for sound, and preliminary tests are looking good. I need some more testing and whatnot, but so far things are looking up.

How to programmatically test whether sound is playing?

Who is online