From: Reiner <reiner1210@googlemail.com>
To: alsa-devel@alsa-project.org
Subject: mm functions vs. normal IO
Date: Mon, 03 Mar 2008 23:40:45 +0100 [thread overview]
Message-ID: <47CC7E6D.4030704@googlemail.com> (raw)
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
next reply other threads:[~2008-03-03 22:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-03 22:40 Reiner [this message]
2008-03-04 7:58 ` mm functions vs. normal IO Clemens Ladisch
2008-03-04 13:55 ` Reiner P
2008-03-04 14:04 ` James Courtier-Dutton
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