Fix .mov where A/V in sync at beginning, ~1 sec offset at end?

[Grahamf]

Basically I have a few .mov files where the audio and video track start out in sync, but at the very end of the video they are out of sync by at least a second, which makes watching the videos rather difficult.

How do I fix this?

[redwudz]

Most likely the audio and video files are different lengths. You could use a program like AVIDemux and demux the audio file out, then process it with a audio editor like Audacity and correct the length. Then mux it back with the video.

This can also be caused by corrupted audio or video files, but that's usually obvious.

I would try to find out why you have the problem. Maybe a bad framerate conversion like PAL<>NTSC or 23.976<>29.97? Or poor cut and paste editing.

What program did you use to convert, if you did? And what steps?

It would also help to fill out your computer details, as we have no idea what OS you are using or what capabilities your PC has.

[Grahamf]

The video seems to be fine... there's some fuzz where the vhs tape was in bad shape.

All I did was start recording

I used EasyCapViewer. i just hit start recording -> motion JPEG. no other options could be changed
Mac OS x 10.6 on first Intel iMac (forget the number), with Intel Core Duo and ATI graphics.

[redwudz]

Both the programs I mentioned can run on the Mac OS. I suspect dropped video frames on the capture may be the problem, especially if the audio runs longer than the video. But try modifying the audio length. Not too complicated a project and probably the easiest way to fix the problem.

If the sync error gets lineally worse, that should work. If the error changes at a certain points in the video, then it can get a bit more complex and you may have to cut the video into sections and treat each sync change separately.