A/V synth problem when combining avis with AC3

[kyle1]

I have 2 AVIs with AC3 sound tracks. Sound track in first file is a bit shorter then video track. When I append second segment, audio track in it looses A/V synth. It happens because VirtualDubMod operates streams separately, and second audio goes just after first audio. I can cut last frames in first segment to get rid of the problem, but I need to kepp ALL frames. If there is a way to combine files without loosing A/V synth?

[Matthew]

You can add dummy audio frames (silence) to end of first AC3. You may notice a slight burp at join point (depends on nature of audio at that point), but sync will be almost perfect. Almost perfect = max of 16 ms off, as each AC3 frame = 32 ms.

[stephanV]

you can also desynch the second video with audio-->interleaving and then save it it with DSC so that it would be in synch with the first video when joined

[kyle1]

You can add dummy audio frames (silence) to end of first AC3
How can I add dummy audio frames?

[Matthew]

There should be a number of posts around about it, but one way of doing it is outined in this thread:

http://forum.doom9.org/showthread.php?threadid=74733

In regards to stephanV's solution, it may be fine for what you want to do, I don't know, but bear in mind that nandub/virtualdubmod will simply insert 0s to achieve the sync, which means the AC3 stream will not be valid.