Problem with XVID Mpeg4 file

[Montaillou]

I have a problem with a file of this type - it's just under an hour long.

If I play it from the beginning, it's fine. But if I try to jump to a later point in the video, it sits there "thinking" for ages - maybe 20 seconds or so - and then, when it's finally found the location, the picture and the sound are WAY out of sync. I haven't been able to work out how far out of sync, because it doesn't even seem to be in the right general vicinity.

Anyway, this contrasts starkly with the behaviour of most AVI/DIVX files I've dealt with, which have no trouble in this situation, and are able to jump instantly to any point in the video, with sound and audio in sync.

So is the file corrupt? If so, is there a (preferably free!) tool out there that could diagnose and fix the problem?

BTW, AVIcodec tells me that the video stream is:

"523 MB, 1334 Kbps, 23.976 fps, 640*384 (16:9), XVID = XVID Mpeg-4, Supported"

The audio information says:

"175 MB, 448 Kbps, 48000 Hz, 6 channels, 0x2000 = AC3, Supported".

And the general details for the file are:

"699 MB (699 MB), duration: 0:54:54, type: AVI, 1 audio stream(s), quality: 72 %".

Thanks in advance!

[admin]

I would simply try re-packaging the AVI file first in VirtualDub, basically load in the AVI file, select "Direct Stream Copy" (important!) from both the audio and video drop down menus, and save as a different AVI file.

If the new AVI file still has the same problem, I would probably try re-encoding it. You can do it in VirtualDub (from video menu, change to "full processing mode", and from the "compression" option in the same menu, select a compression codec), but an easier to use tool may be AVIRecomp.

If that still doesn't work, the file is probably corrupt.

[MilesAhead]

another quick fix

Another quick fix similar to Admin's suggestion you might try is AviDemux. Go to Tools menu => Preferences, then Automation Tab and set the options as shown in the screen shot below.

Load in your file. If it detects a problem with index it will ask should it rebuild or it might ask to unpack the bit stream. Whatever it asks, click Yes or OK. Just wait until it's done.

Video should already be set to Avi or Avi unpack vop.
Set both Video and Audio to Copy.
Click the diskette button to save to your HD. It may play normally after that. If i doesn't, copy to a CD and hit it with a ball peen hammer as a last resort.