Joining AVI's without loosing audio sync ?

[El_Seed]

Here is my problem. I have about 20 AVI segments, all are the same resolution (640 X 480), same audio and video compression (mjpeg) and are of various file sizes. All segments have perfect audio/video sync as far as my eyes and ears can tell. I use Virtualdub to append the segments (direct stream copy) and get a single resulting file which plays fine in Virtualdub & nandub. The problem is that the audio gradually becomes out of sync with the video. Ive done some research in these forums and have come to the conclusion that Virtualdub cant reliably join avi's and maintain audio/video sync. Are there any programs out there that can join avi's and maintain audio/video sync? Or is this a problem with all video editors?
Anyone tried this with Vegas Video 3? Ulead Videostudio 6? Any other video editors?
I use Wndows 2000 with ntfs formatted drives, AverTV stereo TV card, VirtualVCR for capture, Virtualdub for editing.

[Xtasy2002]

The problem is definately not Virtual Dub, I've joined like 1000's of video segments together with perfect sync every time.

You need to be sure all of the segments have the same EXACT video frame rate and that the audio sampling rate is the same in each piece as well.

Now if that checks out, you should use Virtual Dub (Are they AVI files?) to open each segment 1 by 1. Then trim the first second and last second from each clip. The reason is, as I suspect, that each of your segments has a frame or two more audio or more video at the end. In other words when you try to merge them together, you are adding a few extra frames of audio with no video and that pushes the next segments audio up too far, etc.. Trimming them a bit should rectify the problem.