X-Fi Titanium S/PDIF output sample rate

X-Fi Titanium S/PDIF output sample rate

[S. Christian Collins]

I have two sound cards in my system, a Sound Blaster X-Fi Titanium 
(PCI-Express) and an Echo Gina 3G, with the optical output from the X-Fi 
connected to the optical input on the Gina 3G.  I'm looking for a way to 
change the S/PDIF output sample rate on the X-Fi to 48 KHz.  I've tried 
using iecset, but none of the commands change any of the values reported 
by iecset.  Here is the output from iecset:

Mode: consumer
Data: audio
Rate: 48000 Hz
Copyright: protected
Emphasis: none
Category: PCM coder
Original: original
Clock: 1000 ppm

Now, here's the weird thing: even though iecset reports the X-Fi S/PDIF 
rate at 48 KHz, my Echo Gina 3G seems to pick up the stream as 96 KHz 
instead, ie. the Gina 3G becomes "locked" at 96 KHz upon activating its 
S/PDIF input and getting its clock from the optical stream.

I noticed in the Windows driver that the X-Fi's internal sampling rate 
can be adjusted in the driver setting (44.1, 48, 88.2, 96), but the 
S/PDIF rate can't be adjusted.  Instead, the X-Fi's S/PDIF rate seems to 
be locked to the internal sampling rate.

So, it appears that I may need to adjust the X-Fi's internal sampling 
rate somehow, but I have no idea how to do this.  Does anybody know if 
this can even be done?

-~Chris

Re: X-Fi Titanium S/PDIF output sample rate

[Clemens Ladisch]

S. Christian Collins wrote:
> I'm looking for a way to change the S/PDIF output sample rate on the
> X-Fi to 48 KHz.

All I/Os run at the same frequency, the master sample rate.

Creative has implemented only a subset of the hardware's features in
the Linux driver, but this setting is available, if only as module
parameters; see "modinfo snd-ctxfi".


Regards,
Clemens