[vdr] Re: MPlayer+DXR3 and VDR integration

["Dr. Werner Fink" <werner@suse.de>]

On Sun, Jan 06, 2002 at 01:12:26AM +0100, René Bartsch wrote:
> Hi,
> 
> I've checked the specifications of the DVB-S cards from TT and Hauppauge.
> 
> !!! They can't handle AC-3 over the S/PDIF!!!  Sorry, but read it somewhere ...
> 
> But there might be another way to use the SPDIF for AC-3.
> 
> If the AC-3 has been sampled down to 44,1 khz and the frame-headers have been changed, the AC-3 can be transmitted over a
> uncompressed-PCM-only-S/PDIF to an AC-3-decoder.

This I've also suggested a few months ago.  BTW: As long as the PCM isn't
put on an Audio CDROM, you don't need to sampled the 48kHz down to 44.1kHz.

The way I've suggested was: the DVB driver should take AC3 streams
and embbed them into linear PCM (16bit with 48kHz) and put it back
as linear PCM to the PCM-only S/P-DIF of the DVB card.  The only problems
you have are: the DVB-Card should _not_ touch but loop this PCM stream to S/P-DIF,
clearly the DVB driver should mute the analog output and have to control
the sync between AC3 frames and the i-frames.  Don't know if this is
possible with the current DVB cards from TechniSat.

The way to embbed AC3 streams into linear PCM is shown by the programm
ac3iec958 (see http://www.theiling.de/downloads/).


         Werner