Re: via 686a audio driver rate locked at 48Khz

Jeff Garzik
2001-02-28T23:19:45Z

Wayne Whitney wrote:
> I have a system with an MSI-6321 motherboard with the Via 686a
> southbridge, and I'm having a little trouble with the via82cxxx_audio
> sound driver. The stock 2.4.2 driver produces only a rhythmic a buzzing
> sound. I saw a patch here a week or two ago for 'rate locking', so I
> tried that (it didn't apply cleanly to 2.4.2, but I think I applied it by
> hand correctly).

FYI I sent that change to Linus just now, and posted a quick update on
the Web site: http://sourceforge.net/projects/gkernel/

> That patch makes some things work fine (e.g. playing a .wav file), but
> others sound lousy (e.g. playing a 44.1KHz mp3 with xmms). Am I correct
> in thinking that it sounds lousy because of the translation from 44.1KHz
> sampling to 48KHz sampling?

Probably.. If you are locked at 48 Khz, -something- has to upsample to
48 Khz if your audio samples are at a different frequency. Of course
you might also be needing more CPU cycles or memory due to the required
upsampling.

> If so, is there any hope of supporting
> Variable Rate on this hardware?

To be honest I don't know yet. I haven't fully assured myself that the
driver is doing things 100% correctly to set up variable rate. There
-are- codecs locked at 48 Khz, so users with those codecs are stuck at
48 Khz..

> Below is copious debugging output, although not the output of
> via-audio-diag, as I could not find it on sourceforge (and the gtf.org URL
> is gone).

It's in the tarball in the download section of
http://sourceforge.net/projects/gkernel/

Jeff

--
Jeff Garzik | "You see, in this world there's two kinds of
Building 1024 | people, my friend: Those with loaded guns
MandrakeSoft | and those who dig. You dig." --Blondie