re-muxing question

[rubenleon]

When ffmpexX demuxes a file encoded with MPEG2(ffmpeg) and AC3 audio options, the output is a SET of pairs video .m2v files and audio .mp3 files.

E.g: Input = "name.mpg"

Output = ( name-0.m2v , name-0.mp3)
( name-1.m2v , name-1.mp3 )
( name-2.m2v, name-2.mp3 ) , .... (etc)

Which of these video audio file pairs should be chosen as input for muxing ?

[major]

https://www.videohelp.com/forum/viewtopic.php?p=1208160#1208160
I plan to add more functionality to the demux tool (currently based on mpgtx which doesn't demux correctly in presence of ac3 audio), so as to handle this case. In the meantime you should use the "movie audio to ac3" preset, or demux from VOB.

[rubenleon]

Okay I'll tell ffmegX to generate the audio input file (for remuxing) via preset "movie audio to ac3". That takes care of the audio input file.

Now, what about the video input file (for muxing), remember demux generates a set of m2v files, ...

Cheers

Ps: Before posting my question I tried using MPEG Streamclip to demux but it compained that it could not find the last audio (out of sync ?). I read a FAQ to that effect.

[major]

You can also try BBdemux to demux this stream. It should be available on VersionTracker.

[rubenleon]

It does not work.

BBdemux outputs an AC3 file which is not recognised as valid by ffmegX.

The m2v output file seemed ok though. I multiplexed the m2v file with a AC3 file obtained by reencoding with 'movie to audio ac3' preset. As I suspected the audio in multiplexed mp2 was totally out of sync.

I tried every demultiplexing tool I could find, they all yield the same problem as with ffmpegX because they use the same libraries.

So for the time being no remuxing possible for AC3 files or so it seems.

I found a way round my own problem by splitting the mpg2 file with an editor (MPEG streamclip) which I hope will do away with the need for remuxing to preserve quality. I'll know by tonight.

Best

Ruben