It's a 30 minute video.
At one point (around 10 minutes into it), it creates a screeching sound and LOT of artifacts and discoloration, but only for half a second. It's barely noticable.

But when I encode the video to MPG or RMVB or even just try to reencode it into XviD while hardsubbing, the encoded video lags at this part, and it causes a 3 second audio lag/desync after this point in the new encode.

While this is easily fixable in MPG or AVI encodes, I don't have any software to fix desync problems by splicing in RMVB or quicktime encodes, so I tried fixing the original video instead, by cutting out that part.

But I realized VDub cuts out SO MUCH (instead of just half a second), probably at keyframes, which are so far apart... is there anyway I can cut out/fix JUST THAT half-second without re-encoding? (because the original's quality is already pretty bad as it is, plus re-encoding will cause that desync problem).