Re: [Alsa-user] Default sampling rate for via82xx and 48kHz

[Clemens L. <cl...@la...>]

Philip Prindeville wrote:
> Lee Revell wrote:
> >On Tue, 2005-07-12 at 19:25 -0600, Philip Prindeville wrote:
> >>I was looking at the code for via82xx.c, and noticed that there
> >>are a lot of places where 48kHz is hard-coded into the driver.
> >>
> >>There are newer architectures (and higher end motherboards)
> >>where the default sampling rate is 96kHz... and the default sample
> >>with is 24 bit, not 16 bit.

AC'97 doesn't support more than 20 bits.

> >Because the devices supported by that Via driver only go up to 48KHz.
> >If you have onboard 24/96 sound I think you probably have an Intel HDA
> >codec.
>
> Not quite.  The latest codec device from VIA is the VT1617A, which has
> 8 channels, and a 96kHz rate.

But not at the same time.  Using 96 kHz is only supported with two
channels, and using 8 channels works only by using the two AC'97 slots
ordinarily allocated for SPDIF output.

It might be possible to support these enhanced features, but only if
the AC'97 controller chip (the VIA 82Cxxx southbridge) supports them,
too, and if we had documentation for these features.

So far, 96 kHz and/or 20 bit samples are only supported with Intel
controllers (snd-intel8x0).


HTH
Clemens