The real pros are
very experienced with filters, and can take a horribly-rendered film off a DVD VOB-set and produce output which is
much better than the actual DVD itself.
My skills, which I describe as "somewhat above average" yielded the following:
Von Ryan's Express
That was easy, however, since it involved the original VOB-sets; repairing AVIs is harder because it requires repairing already lossy, and possibly hopelessly destroyed, video.
The biggest problems commonly encountered with already lossy video are:
* severe chroma blocking, especially in dark areas
* grainy
* blurry (as a result of crummy re-sizing filters)
* crappy deinterlacing (much of which may be impossible to resolve on a tertiary basis)
* uncropped scummy edges
* "tinny" or "croaky" timing (i.e., European/PAL release of originally 24fps film, etc)
* screwed aspect-ratios.
Dealing with severe blocking and bad interlacing in already-decimated 23.976fps material is, IMO, extremely frustrating.
-- I would LOVE to death anyone who'd write a non-bug-ridden GUI incorporating all of the wonderful tools at
MSU