In the case of the videos that are in FS2, it is possible to have a better recompressed version.
I'm not saying that a 100% perfect copy of the original is possible, but that it's possible to make the new version look better than the original relatively easily.
This is because for some odd reason, the FS2 movies seem to have been compressed poorly, making them really blocky and ugly in places (meanwhile, the FS1 movies look A1 superb).
So by filtering it properly (actually, even simple deblocking helps a lot already), the resultant video can actually look better than the original.