On Wed, 19 Dec 2007, Miloslaw Smyk wrote:
Hi,
My app needs to know about the events occurring to a sound card. Specifically, I am interested in start, stop, pause and volume change. While I could monitor volume by similar means as alsamixer does (is there any doc on this apart from the source code?), I am not sure if monitoring other events is at all possible. I would appreciate any suggestions as to how to do this.
You may write a simple monitor plugin to alsa-lib and create an interface to send these events to your code (shm, socket or so). Or you can monitor (periodically read) /proc/asound/card/ files (but they won't tell you the reason why stream stopped).
Jaroslav
----- Jaroslav Kysela perex@perex.cz Linux Kernel Sound Maintainer ALSA Project