Very unusual audio sync problem

[scorpio47]

Hello all:
I am having a very unusual sync problem while using AutoGK. I am converting some high quality files I've made down to lower resolution for use on my PDA. The source file's audio is sync'd perfectly, but the resulting file is not. Here is the weird part: The resulting file STARTS out perfectly sync'd, but gradually becomes more and more out of sync, and is a good 3 or 4 seconds off near the end. I've tried extracting the source audio as a wave and resampling, that doesn't work. I've also tried using virtualdub first to resample the source audio only and use direct stream on the video, but that did not work either. Any ideas? I've had sync issues that I've been able to resolve before, but this one has got me quite stumped.

[redwudz]

If the sync gets worse as the video plays then the simple explanation is that either the audio or the video are different lengths. Adjust the lengths and that should fix the problem. The 'why' may be a little more complicated. Was there a framerate change or VBR audio involved?

[olyteddy]

Can VBR Video also cause the slipping of Sync?

[guns1inger]

It can. I have also seen VBR audio cause sync to shift out and back to varying degrees through a single track.

[scorpio47]

I thought of different track lengths too, but the extracted audio is the same length as the video. Tried frame rate experiments too... changing them, keeping them same. End result is the same.