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

[Wolfgang Fiesel <fie@iis.fhg.de>]

Hello,

as I promised last week,
now AC-3 over Digital Output (SPDIF) for DVB-S is reality (recordings
and DVD playback).
Of course if the recordings doesn't include any AC-3 data the SDPIF
output will be operate like before (raw PCM).
I'm using DVB-S version 2.1 (Hauppage)

It's time to throw away the soundcard and forget the -a switch.
Nevertheless I modified the code very carefully and minimized the
patch effort. Therefore all previous AC-3 playmodes (-a switch) should
also operate like before.

How does it work ?
The secret is the IEC 61937 paper which describes the wrapping of AC-3,
MP3, DTS, ... into raw 16 bit PCM data. Finally the LPCM
transport feature of the DVB driver was the key to realise it.

The patch is related to Klaus latest update version (vdr-0.99) to get a
chance
to be integrated if the test phase should be successfully. Since two
days I've check it by myself with different AC3 recordings and DVD's. Up

to now all start/stop actions seems to be right, no AC-3 dropouts seems
to be happened. Please test it also very stressfully.

Enabling the feature:

Please compile VDR with the switch AC3=1 (in addition with your
favourite switches), that's all. Afterwards all AC-3 information will be

transported over the digital output. (make clean!!)
On the other side VDR is operating as usual (only PCM over digital
output) if you don't use this switch. No modification of internal stream
handling.

You have to change the following files:

1. ./VDR/dvbapi.c -> dvbapi.diff
2. ./VDR/Makefile -> Makefile1.diff
3. ./VDR/ac3dec/decode.c -> decode.diff
4. ./VDR/ac3dec/Makefile -> Makefile2.diff

(call "patch -p1 original diff-file")

Here is the patch file:
http://www.fiesel.de/download/ac3patch.tar.gz

Enjoy the liberty of digital music

Wolfi