Multiple simultaneous sound channels (sources) with and Envy24 (M-Audio Audiophile 2496)

Ariff Abdullah ariff at
Thu Dec 18 14:14:06 PST 2008

On Thu, 18 Dec 2008 15:58:18 -0500
"Scott Spare" <scuppers at> wrote:
> Stefan,
> Thank you for your detailed message. I am more than willing to test
> any new driver code for Envy24 that supports multiplexing if anyone
> creates it.  I looked at the code for the driver yesterday, but
> realized after about half an hour of reading code that driver
> debugging is way beyond my C ability.
> I was unable to figure out what that high-quality hardware mixing is
> called in the driver, or whether it's just automatically enabled,
> and so would be something that would have to be disabled explicitly
> by sending a signal to the chip to tell it not to use it.  I would
> be very glad to use the hardware mixer if it was working.  Also I'm
> not really clear on what portion of all this is handled by the
> driver itself, and what's handled by the kernel modules.
> I looked around for datasheets for the VIA Envy24 chip itself, and
> couldn't find those.  I personally thank Konstantin and whoever else
> authored these drivers in the first place. How they did so without
> datasheets, I will never know.
> FWIW, there's a web page on the chip itself at
> The digital mixer is shown on that page in a block diagram, but the
> quality of the diagram is not so good.  There's a zip file for an
> "image kit" on that page, but that's just logos.
> Next steps: I think I'm going to try OSS again and see if I can get
> that virtual channel mixing thing working.  I might also look at the
> source of their envy24 support to see if that answers anything.  I
> kind of doubt it, but it's worth a shot.  I'd really prefer to use
> some kind of low-level solution like the hardware mixing or FreeBSDs
> vchans.  I think the driver may be disabling the vchans, but not
> sure.
> The driver itself has been working great with libao besides the
> multiplexing issue.  I use it every day to play music on Amarok. 
> What a great card. Thanks once again.

Dejavu. I'll look into this.

Ariff Abdullah

... Recording in stereo is obviously too advanced
    and confusing for us idiot ***** users :P ........
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