[Ffmpeg-devel] alsa input / output

Luca Abeni lucabe72
Tue Dec 19 16:48:27 CET 2006

Hi Stefan,

On Tue, 2006-12-19 at 16:26 +0100, Stefan de Konink wrote:
> On Tue, 19 Dec 2006, Luca Abeni wrote:
> > 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?
> Would you really want to do this?
Well, it looked like something to try just for the fun of it :) (and to
understand how alsa work at a low level...)

More seriously, it happened to me to compile ffmpeg with alsa support on
a computer, to copy it on a different computer, and to be unable to run
ffmpeg on the second computer because libalsa was not installed there
(or a different version of alsalib was installed, I do not remember).
So, I wondered why a new dependency on alsalib was really needed, and I
had this funny idea of directly accessing the alsa drivers...

>  Everytime the format changes you need to update the code.
By "format" here you mean the kernel <---> userspace interface?
If yes, I do not think it can change during a stable kernel release
(Linus would never allow to break US in this way, I hope).
If such interface changed, a new version of alsalib would need to be
installed, creating a manteinance nightmare...

Copy this in your signature, if you think it is important:
                               N O    W A R ! ! !

More information about the ffmpeg-devel mailing list