Re: SPDIF and cs46xx ?

[Gregoire Favre <greg@ulima.unil.ch>]

On Sun, Mar 30, 2003 at 03:11:00AM +0200, Benny Sjostrand wrote:

> Seems like a user application problem to me.  The cs46xx driver just 
> support a limited set of period-size configurations, that's a limitation 
> in the HW. Then it's up to the application to handle it (I guess)
> I've managed to make AC3 and DTS through SPDIF work witth OGLE and Xine, 
> I dont see any reason why it would'nt work with any other application, 
> at least you should get further than: "S/P-DIF: Period size not 
> available: Invalid argument" then when you've managed to open the device 
> and write data to it maybe there will apear other unknown problems ...

Well, I think there are two problem, the first one is the limited set of
period-size configurations which the bitstream plugin should take care
of, but the real reason I repost what Dr. Werner Fink wrote in the
vdr@linuxtv.org mailing list was because he spoke exactly about a
problem we are a lots to have with the cs46xx driver :-(
Also found relative to DVB (AC3overDVB from Stefan Huelswitt,
http://www.muempf.de/down/vdr-1.1.26-AC3overDVB-0.1.4.diff.gz ) which
contains in the README.AC3overDVB:

If your receiver doesn't detect the encapsulated stream (at the
beginning of replay in general) you will hear the digital data played as
PCM data. It's a spiky noise. Don't turn up the volume too much, or the
speakers may be damaged. You have been warned!

And afterthat I post the answer from Dr. Werner Fink:

As long as the hardware on the DVB cards are not able to put
the 16bit none audio PCM data stream into a 32bit none audio
S/P-DIF transport stream all receivers which uses the bit flags 
of the S/P-DIF transport stream for identifying none audio
loose.  All S/P-DIF data get from the DVB card to not have the
none audio bit set.  AFAIK this is a hardware bug (or better
this is the information I've got from TT) ...

And what I think is that we have exactly the same problem with the
cs46xx driver: I couldn't have a real 5.1 with any tools under linux and
cs46xx (ac3dec,ac3play,mplayer,xine), in fact I couldn't alsa hear the
sound from the CD using the SPDIF...

I think we need a fix for some receiver that don't detect the
encapsulated stream...

Thank you very much,

	Grégoire
________________________________________________________________
http://ulima.unil.ch/greg ICQ:16624071 mailto:greg@ulima.unil.ch


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