Subject: Re: Pseudo audio device
To: Brian Buhrow <buhrow@lothlorien.nfbcal.org>
From: Jared D. McNeill <jmcneill@invisible.ca>
List: tech-kern
Date: 11/11/2007 07:22:34
On Sat, 10 Nov 2007, Brian Buhrow wrote:
> Hello. I'd love to see this. I can think of times when when I could
> have used pcm audio data directly somewhere, but wanted to use the audio
> subsystem to get it. It would be especially cool if you make it so that
> multiple pseudo audio devices can be attached. Then you could do audio
This should already be possible.
> mixing through a hardware sound card by piping multiple data streams back
> to an open pipe to a hardware sound device. (Probably trashes OS
> performance with all that copying in and out of the kernel, but we still
> don't have multiple voice support on most sound hardware, and the
> kent-audio project appears to be dead.) This driver might obviate much of
> the need for that work.
That's very interesting. The only thing it doesn't give us is
multiple-open support on /dev/sound, but this isn't a huge deal -- back
when I was working with esa(4), I wrote an audiomux pseudo-device that I
pointed to from /dev/{audio,sound}, and an open of this device would
redirect to the first /dev/{audio,sound}N that was available.
Cheers,
Jared