Re: Siemens DVB-C capabilities with Linux driver

[Peter Hofmann <junk@pxh.de>]

Hi,

On May 8, 18:11, Klaus Schmidinger wrote:
> Subject: Re: Siemens DVB-C capabilities with Linux driver
> Ralph Metzler wrote:
> >
> > Peter Hofmann writes:
> >
> >  > - Will it be possible to let the DVB-C card decode the MPEG-2 video
> >  > part of a DVD and output the AC3 stream to an external AC3 decoder?
> >
> > Yes.
>
> Is there any information available on how to extract the AC3 data?

My question referred to DVD playback using the DVB card. There is software
available from the Livid project that can do demultiplexing of DVD VOB files.
At the moment the AC3 stream is downsampled to stereo by the ac3dec program. My
idea is to let an external AC3 decoder handle the AC3 stream. This would result
in much better sound quality than available with cheap soundcards. I know that
some soundcards have the ability to output AC3 directly (eg. the Soundblaster
Live!, see www.alsa-project.org).

Whether a given S/PDIF output has the ability to output AC3 (or any arbitrary
bitstream) depends on the programmability of various bits in the S/PDIF
headers. Some cards seem to have this hardcoded.

> Does it come with the normal AV_PES data from /dev/video?
> What sort of hardware interface (i.e. connector type, optical/electrical)
> is usually used to transfer the AC3 data to an external decoder (sorry,
> I don't have such a decoder yet, so I was wondering...).
>-- End of excerpt from Klaus Schmidinger

I also don't have a decoder yet. The DVB-C card (and most of the soundcards
that have S/PDIF) has a coaxial S/PDIF output (electrical).

Peter

-- 
Peter Hofmann                  e-mail: junk@pxh.de