[Ffmpeg-devel] alsa input / output

Luca Abeni lucabe72
Tue Mar 20 12:42:46 CET 2007


Hi Baptiste,

Baptiste Coudurier wrote:
[...]
>> Is anyone interested in this alsa format? If yes, I can send it to the
>> list so that interested people can try it, and improve or fix it (in its
>> current form, I do not know if it can be submitted for inclusion...)
>>
>> Also, just for the fun of it I am thinking about accessing alsa without
>> using alsalib (by directly accessing /dev/snd/*). Does anyone know where
>> can I find some documentation about the "raw" /dev/snd/* interface?
>>
> 
> Any news about this ? Im interested in testing alsa output format from
> ffmpeg.
I sent my alsa patch some time ago, but it was hidden in the 
"ffserver/ffmpeg Live Video: Anyone get it to	work	with sound?"
  thread, so people can have missed it; sorry about that. It should be 
in the list archives; if not, let me know.

Anyway, in its current form the patch works (at least, it worked for me 
:), but there are a lot of things to clean up (I have no time right now, 
but I'll probably return to it in the future). See Michael's initial 
quick review for some more details.
I captured some audio and video, and they happened to be on synch (even 
if audio PTSs are not generated in a very accurate way).

Audio output worked too, but it was not in synch with video (I used a 
"GTK output" format for testing).

The code currently uses alsalib, because I did not find any 
documentation about how to directly access raw alsa devices.


				Luca




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