audio goes out of sync after demux/remux

[aikox2]

I have a concert DVD (VIDEO_TS Folder with VOB files), and the audio is only on one channel, so I wanted to copy it to the second channel and reauthor the DVD.

I used DVD Decrypter to demux the streams, then I used Womble to duplicate the left channel to the right, and remuxed.

The resultant MPEG starts out in sync, and gets progressively out of sync throughout the next hour and forty minutes. The original DVD is in sync.

I guess I am using the wrong tools and/or techniques.

Any advice or help would be greatly appreciated.

Thanks,
Aiko

[castellanos]

It would be interesting if you tell us the audio format of you DVD source: ac3, wav?
When you duplicated the channels, did you keep the Khz as the original or you change it? (48Khz --> 44.1Khz)
Greetings!

[aikox2]

Thanks for the reply.

The audio stream is AC3. I did not change anything; I just let Womble do its thing. Womble allows you to duplicate the left or right channel, which is wht I needed to do. The AC3 is 48 Khz, 256 Kbs.

Any suggestions?

Aiko

[[)370|\|470!2]

Did you compare length of both streams? It is obvious though, that
womble did lame job there. Perhaps you should try some another tool.
I'd rather do it this way: 1. convert an original mono ac3 to .wav.
2. convert resulting mono .wav to stereo using some wave editor.
3. encode resulting stereo .wav to .ac3 back again, using scenarist
transcoder or some similar tool. There's some free tools available
for it too iirc,
so if you don't have scenarist transcoder check besweet thread.