[mythtv] [Experimental PATCH] BIG DVB PATCH V3.2 Released

[James Armstrong]

> For my case its not. Something is still wrong somewhere, I don't know 
> what yet. The patch I did to mpeg.c allows me to use the software ac3 
> decoder. This patch may very well be an introduced bug to cancel out a 
> bug which I can't find yet.
>
> I am in Australia, where broadcasts are transmitted in the DVB format. 
> For my case  ip->cid is already 0xbd for AC3, 0xc0 for MPEG2 audio, 
> and 0xe0 for video when CorrectStreamNumber is called (I only run it 
> for a short while so I may very well be wrong here)..
>
> The original function replaces all audio with 0xc0 (hence everything 
> calls the software mpeg decoder),  but the patch in DVB v3.2 just sets 
> ip->cid to the same original value (which is better as even if/when 
> the original value is wrong, the new CorrectStreamNumber will 
> hopefully set it correctly).
>
> AC3 passthru to an external AV receiver may work just by fixing up 
> CorrectStreamNumber (I don't know as I don't have a AV receiver), but 
> software decoding doesn't work, mythfrontend crashes on my machine at 
> ScanStreams.
>
> Just found out that in ScanStreams, the line:
>
> AVCodec *codec = avcodec_find_decoder(enc->codec_id);
>
> evals to nothing as enc->codec_id = 86021 which is 0x15005 which is 
> CODEC_ID_DTS. (incidently I couldn't register the DTS codec). I am 
> tempted to just swap the order of CODEC_ID_DTS and CODEC_ID_AC3 in 
> avcodec.h and see if it works. At the moment trying to find out where 
> 0x15005 comes from.
>
> My apologies for the misconceptions in the A52/AC3 specs... :(
>
Does anyone know if this will fix the problem I have with playing back 
HD recordings from ABC here? I only get audio out the front right 
speaker using OSS Emu and with ALSA I get choppy/broken audio out the 
same speaker. With mplayer I get good audio out all speakers. In mplayer 
with debug is says it is using a codec (liba52 or something like that) 
to decode the ac3 audio.

- James