On Fri, 12 Dec 2003, Geoffrey Martin wrote:
> Hi,
>
> I'm using the following:
> IBM T40 laptop
> Digigram VXPocket v2
> RedHat 9
> Kernel 2.4.22-ac4
> ALSA drivers 0.9.8
> vxloader 0.9.7-i686
>
> Measurement gear
> Audio Precision System Two Cascade
> PrismSound DSA-1
>
>
> Some of my other gear is having difficulties locking to the S/PDIF output
> of the card at 44.1 kHz and I have a suspicion as to why this is
> happening...
>
> I have control over the sampling rate of the S/PDIF output of the card as I
> would expect, however...
>
> In the S/PDIF Channel Status Block information there is a portion of Byte 3
> that is used to send the intended sampling rate (selectable between three
> values, 32 kHz, 44.1 kHz and 48 kHz, depending on the arrangement of bits
> 0-3 in Byte 3. For specific information on this, please see Application
> Note AN22REV2 from www.crystal.com). It is also possible, using bit 0 of
> Byte 0, to indicate whether the signal is Professional or Consumer format.
>
> Using my present configuration, I do not appear to have control over either
> of these two variables. For example, even when I am sending a 44.1 kHz
> signal at a rate of 44.1 kHz (or close enough... it's actually 44.0993, -17
> ppm) Byte 3 of the Channel Status Block is saying that the signal is a 48
> kHz transmission.
>
> Are the VXPocket drivers in ALSA capable of changing these values in the
> card? The official drivers for Mac OSX allow me to change the Pro/Consumer
Yes, use 'iecset' utility from alsa-utils for example or alsactl and
reedit your configuration file (look for IEC958 controls).
> flag using an application, and the sampling rate indicator changes
> automatically with the actual sampling rate of the card's output.
We might change the behaviour later. Actually the PCM rate and S/PDIF
indicated rate might differ in the current vxpocket driver.
Jaroslav
-----
Jaroslav Kysela <[EMAIL PROTECTED]>
Linux Kernel Sound Maintainer
ALSA Project, SuSE Labs
-------------------------------------------------------
This SF.net email is sponsored by: SF.net Giveback Program.
Does SourceForge.net help you be more productive? Does it
help you create better code? SHARE THE LOVE, and help us help
YOU! Click Here: http://sourceforge.net/donate/
_______________________________________________
Alsa-devel mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/alsa-devel
