[FFmpeg-user] How can I convert mpeg2 5.1 audio to ac3?

bluesky at caramail.com bluesky at caramail.com
Tue Nov 4 20:12:56 CET 2014

"Carl Eugen Hoyos" <cehoyos at ag.or.at> wrote:

> Unfortunately, you can get neither support for XBMC
> nor MythTV here (the relevant question to them is
> probably: Are you reencoding my MPEG-2 two-channel
> audio to AC3 instead of sending it as PCM to give
> the receiver a better chance to know what to do?),
> I will hopefully open a ticket for PLII decoding,
> I have no idea how difficult / trivial this is
> given that we support encoding...

Thank you. That is all I can hope for. Given my lack of technical understanding I suspect I have taken this as far as I can go for the moment.

It would be really great if ffmpeg could detect these channels and reencode them to a more standard (if that is the way to put it) ac3 format. XBMC WILL play Dolby encoded files correctly if the channels are all present and not encoded in some weird format, in fact it is very good at that. Also, it actually indicates that such files are 5.1 rather than 2.0. The problem is that although I have been able to get ffmpeg to create a 5.1 channel ac3 .ts file (using the -ac 6 option, as mentioned in my original post), it does not seem to be decoding the channels from the original file correctly and therefore is not placing them into the output file correctly. So basically I would get like to get the channels extracted from this weird PLII format and into conventional ac3, if that makes any sense (I apologize if I am not stating this correctly but hopefully you understand what I mean). If there is any way you can accomplish that, that would be great!

More information about the ffmpeg-user mailing list