[alsa-devel] mm functions vs. normal IO

[Reiner]

Hello,

I'am new for using ALSA API.
I was astonished that a simple wav playback example does not exist. But 
after reading the pcm examples I have managed to make one (if I will 
finish it I can post it so it can be added to the examples)

Now my question:

What should be used:

snd_pcm_mmap_commit 
<http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m___direct.html#g3e3d8bb878f70e94a746d17410e93273> 
(I think snd_pcm_mmap_writei 
<http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m___direct.html#g3a811efcd9d64b60e6a25df6924d26b0>  
is the same with an additional copy behind ?)
or
snd_pcm_writei 
<http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m.html#gf13067c0ebde29118ca05af76e5b17a9>

I think mmap will have better performance, but will it work with all 
soundcards? Or should it be in a config what to use?

I'am also looking for a function to get the number of played frames. I 
have played around with "snd_pcm_status" but it seems not to have a 
counter for this.

By the way is there a detailed tutorial (introduction) for ALSA 
available? The online help is a little bit too short for newbies. ;-)

Reiner