[vdr] Re: AC3 over DVB-s is possible - Part2

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

On Tue, Feb 19, 2002 at 08:30:39PM +0100, Emil Naepflein wrote:
> On Tue, 19 Feb 2002 11:13:28 +0100, Wolfgang Fiesel <fie@iis.fhg.de>
> wrote:
> 
> > as I promised last week,
> > now AC-3 over Digital Output (SPDIF) for DVB-S is reality (recordings
> > and DVD playback).
> 
> For live viewing the transfer mode of VDR may be useful. The data is
> read out of a secondary card if available and than converted and pushed
> back into the primary card.

Maybe it would be possible with the same trick as with dynac3cat
from Ulrich Roeder <dynamite@efr-net.de> send a two or three days ago.
Simply an ioctl DMX_SET_PES_FILTER with the pid of the AC3
stream on /dev/ost/demux and read ac3 from /dev/ost/demux.

Nevertheless: the question is: Why not doing this in the driver
its self?  Wolfgang has shown that AC3 wrapped/embed accordingly
IEC 60958 into an IEC 958 data stream can be routed through the
cards S/P-DIF.  In other words, there is no reason to go through
user space and back to kernel space but do the same stuff within
dvb_filter.c because there are the many functions for audio, video
and AC3 available from the mpegtools included in the application
tree of the DVB driver.

In other words the ioctl AUDIO_SET_BYPASS_MODE should get live
within DVB (currently it is -EINVAL).


       Werner