[alsa-devel] SPDIF audio / non-audio bit
tiwai at suse.de
Fri Aug 15 18:01:10 CEST 2008
At Sat, 16 Aug 2008 01:56:14 +1000,
Ben Stanley wrote:
> On Fri, 2008-08-15 at 16:59 +0200, Takashi Iwai wrote:
> > At Sat, 16 Aug 2008 00:45:33 +1000,
> > Ben Stanley wrote:
> > > Could you please clarify
> > > 'independent PCM IEC958 status bits' vs
> > > 'default IEC958 status bits',
> > > perhaps by pointing out some drivers implementing each type?
> > Run the following:
> > grep -r 'IEC958.*PCM_STREAM' sound/pci
> > These drivers have "IEC958 Playback PCM Stream" controls. These
> > controls are assigned to PCM streams, and changed individually from
> > the "IEC958 Playback Default" control. When the PCM stream is closed,
> > it's back to the status of "IEC958 Playback Default".
> Thanks for the info.
> > > > You can change the status easily via iecset program in alsa-utils.
> > > I note here that iecset does not accept --device=hw:0,1 for example. Any
> > > reason for this?
> > Because it's invalid. The --device option is for a control device,
> > not for a PCM device. If you want to change the secondary control
> > (i.e. "IEC958 Playback Default" with index=1), pass "-n 1" to iecset.
> um, that doesn't work either.
> mythtv at mythtv:~$ iecset -D=hw:0 -n 1 audio on
> iecset: invalid option -- n
> Usage: iecset [options] [cmd arg...]
> -D device specifies the control device to use
> -c card specifies the card number to use (equiv. with -Dhw:#)
> -x dump the dump the AESx hex code for IEC958 PCM
> -i read commands from stdin
> professional (common)
> off = consumer mode, on = professional mode
> audio (common)
> on = audio mode, off = non-audio mode
> rate (common)
> sample rate in Hz
> emphasis (common)
> 0 = none, 1 = 50/15us, 2 = CCITT
> lock (prof.)
> off = rate unlocked, on = rate locked
> sbits (prof.)
> sample bits 2 = 20bit, 4 = 24bit, 6 = undef
> wordlength (prof.)
> 0=no, 2=22-18bit, 4=23-19bit, 5=24-20bit, 6=20-16bit
> category (consumer)
> copyright (consumer)
> off = non-copyright, on = copyright
> original (consumer)
> off = 1st-gen, on = original
> I see that I have alsa-utils 1.0.15-3ubuntu2 (from ubuntu 8.04). Perhaps
> my version is too old?
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