VirtualDub - resyncing audio?

[Jonz]

Hi,
I have used FRAPS to record some games and I used vDub to merge the files togheter. However the video resulted to have unsynced audio and I lost the original files, it less apparent at the beginning but toward the end it have a delay about 2 seconds . Is there a way in vDub to readjust the audio to synch the video?

[redwudz]

Usually when the sync error gradually increases by the end of the file, the audio and video lengths are different. This can happen from framerate changes or bad cuts and pastes or a few other operations. Most times I demux out the audio and correct the length in Audacity, then mux it back with the audio. I leave VD open during this time, then it's easy to mux back in the corrected audio and 'Direct stream copy' the repaired file.

[Jonz]

How easy it is? It a bit hard to know where the sound begin to unsync and the audio ends just as the movie. I don't really know how Audacity can help me as I can't tell how to match the sound to the video.

[davexnet]

Probably best to rewrite the file in Virtualdub as direct stream video and PCM audio. Then see the troubleshooting in this thread:
https://forum.videohelp.com/threads/257022-How-to-fix-audio-synch-problem-in-AVI-file

[Jonz]

I kinda found a fix regardless. My remedy is to make a slight time compression on the audio track. I did it with Premiere but I rather do it in vDub because Premiere don't let me export my movie in raw AVI video like vDub usually do.

Is it doable in vDub? Or I have to pick Audacity?

[davexnet]

Vdub does have a time stretch facility in audio / advanced filters, but I've never used it myself.

[Jonz]

well I can't access the Advanced option because it grayed.

But I think I have found an alternative, by playing with Audio/Video Interleaving I think I get some similar results. Not sure what it does tho or how it will react when gluing clips togheter.

[davexnet]

To access those tools, you have to first enable audio/full processing mode.