I'm a bit confused. When people share .vob files over the internet, they always convert them to .avi first. Then, if I want to watch on my DVD player, I've got to convert them BACK from .avi to .vob. So Is there any quality loss at all? Also, why is it necessary for people to first convert files from .vob to .avi before sharing them? Why not just send the original .vob files? Is it because converting to .avi makes them smaller in size? If so, then I'm back to fist question about the drawbacks (if any) to converting from .vob to .avi.

Yes, there is loss every time you convert them from one lossy format to the other. VOB files can only be 2 gigs in size so usually there are several VOB files per movie. Converting them to AVI not only makes them into one easy file to download but they are usually compressed even more so they are smaller in size. And yes, this also causes degredation in the movie.

That should have read VOB files are only one gig in size, not two

I heard that .avi is not a lossy format. So are you saying the lossy effect takes place when converting from VOB - AVI, AVI - VOB, or both situations?

AVI is just a container for many types of codecs. There are a good 15 different types of codecs/formats used for AVI, some lossy some not. It all depends on how it was encoded. However, if the VOB was encoded in a non-lossy format, the AVI file would be enormous. Probably 20 gigs or so for an average movie. But even if th AVI was non-lossy, you would lose some clarity on encoding it to the standard MPEG2 format for DVD. And since the AVI was transcoded from a DVD which is lossy, this would be the second pass on a lossy format so yes, you would still see degridation from the original.

That should have read However, if the AVI was encoded in a non-lossy format, the AVI file would be enormous.

so what is the best codec to capture a DVD movie and send over the internet without loosing quality? Is there a program that can be highly recommended to achieve this?