Put a foreign dub track over HD version of video

[Keitaro004]

Hello!

I've recorded a cartoon to my HDD in my own local language, but the video quality is very low (below 480p). I got my hands on a 1080i version of this in English and want to put the dubbed audio into the video (extracted with MKVMerge). But no matter what I do, the audio doesn't seem to match. I've tried delaying the audio, but it only works for about 15 seconds before the audio goes out of sync again. It seems like the audio is a lot faster than the video itself and just keeps jumping forward.

What to do?

[Baldrick]

Have you compared the running time? Same?

But they could be edited different and then wont you find any easy method to sync it. Maybe easiest with a nle/advanced editor where you can see/edit/preview the video and audio tracks.

[Cornucopia]

Yes, I would put both V+A of both streams into an NLE and do a side-by-side composite (probably also panning the soundtracks as well).
For synchronization editing purposes only, obviously. Then set the output to be only the desired streams.

Scott