Subject: Re: Pseudo audio device
To: Jared D. McNeill <>
From: Brian Buhrow <>
List: tech-kern
Date: 11/10/2007 23:55:57
	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
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.
On Nov 10, 10:25pm, "Jared D. McNeill" wrote:
} Subject: Pseudo audio device
} Heyas folks --
} I'm wondering if there is any interest in a pseudo audio device driver 
} that does nothing but push raw PCM data back to userland.
} I discovered the rtunes project ( 
} today, which transcodes WAV and PCM data to Apple Lossless Audio, then 
} pumps the data to an Apple Airport that supports AirTunes. So that's 
} kind've cool, but I need to either pipe PCM to the rtunes application, or 
} modify existing applications to use the rtunes support library.
} Instead of this, I wrote a simple audio device driver that pushes raw PCM 
} back to userland. It allows me to redirect the PCM data written to an MI 
} audio device back to userland, and I fed this data into rtunes for 
} seamless operation with any audio consumer.
} So, I ask -- is there any interest in this pseudo-device driver?
} Cheers,
} Jared
>-- End of excerpt from "Jared D. McNeill"