[alsa-devel] Using MMAP feature

Clemens Ladisch clemens at ladisch.de
Mon Jul 23 12:38:27 CEST 2012

alberto Villa wrote:> Hello,
> I'm going to use the MMAP feature of ALSA.

Why do you need to do this?

> snd_pcm_mmap_begin(capture, &c_area, &c_offset, &c_frames);
> it keeps to return c_frames = 0: is it right ? what does this mean?

It means that there are no samples available at the moment.
(Or that you forgot to call snd_pcm_avail_update(), or that you
didn't set c_frames before the call.)


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