Using MMAP feature

[alberto Villa <a.villa@seletech.com>]

Hello,

I'm going to use the MMAP feature of ALSA. I understood I have to use 
snd_pcm_mmap_begin and snd_pcm_mmap_commit functions, but I can't 
understand the meaning of some parameters in  the snd_pcm_mmap_begin 
function: when I call this function in order to have access to the 
capture stream on a call like this:

err = 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? is 
the buffer full so that I can read samples or the available contiguous 
space to be read is 0?

Thank you,

Alberto

-- 
Dr. Villa Alberto
Sw Engineer

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