[LAD] soundcards and clocks

Dmitry Baikov dsbaikov at gmail.com
Tue Oct 21 15:41:45 UTC 2008


On Tue, Oct 21, 2008 at 5:34 PM, Julien Claassen <julien at c-lab.de> wrote:
> was a timer derived from the soundcard "clock". ALSA offers an API for the
> timer. does anyone know if they really derive tat timer from the soundcard?
Possibly, but better ask some ALSA guru.

>  2. If some application already uses audio, is there a way for another app
> to at least listen for those regularly triggered interupts?
You will need some kind of a daemon that will have a DLL and will
provide the data via shared memory.
In fact JACK does exactly this.

>  About JACK: Does the JACK api offer a function to use the audio clock info?
jack_get_time(), jack_time_to_frames() and jack_frames_to_time()
they to map nframes and jack's time, but the only portable way to map
this to system time
is to use another DLL.

Maybe ALSA timer API is possibly what you really want.

Best,

Dmitry.



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