[vdr] Understanding AC-3
rob at davis-family.info
Thu Sep 2 15:21:56 CEST 2010
How do you go about understanding AC-3 within a VDR context?
(apart from reading up on it online - which now has my head spinning).
I have a Hauppauge PVR-HD and two ATSC cards. The ATSC cards work as
they should and with the new atsc/dn patch on 1.7.15 now have the
However, if I turn on add new transponders or update pids, then my
Hauppauge PVR channels lose their dpid values..
Sep 1 19:10:33 oac vdr:  changing pids of channel 920 from
4113+4097=27:0;4352=eng at 106:0:0 to 4113+4097=27:0:0:0
If I keep automatic channel updates off, then xineliboutput and
streamdev work for these channels, but vdr-vnsi (xbmc) and vdr-xine
don't (no audio)..
I'm assuming vdr parses the ac3 headers in some way and sends
information onto the playback frontend. How would I go about seeing
what those headers might be and looking into patching pat.c accordingly?
I noticed all the comments about e-ac3 and wonder if a similar patch
should be made for this device.
As an aside, vdr recordings from these channels play back fine in vdr-xine.
So, more specifically, I suppose I would like to know how to find out
I'm pretty sure it falls under this:
case 6: // STREAMTYPE_13818_PES_PRIVATE
But I'd be interested in seeing the flow through this section of pat.c
and what is happening.. Mainly to see if something needs to be forced on?
I can create a five second VDR recording if someone wants to see what
the TS stream looks like.. But I'd be interested in diagnosing it myself..
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