the 650mb part is sketchy.. thats if its a full XviD/DivX movie, full SVCD/VCD movie, or DVD.

i've seen one CD of a VCD go as low as 450mb-500mb.

i wouldn't download some movie like what ever movie.mpg -- i'd find a movie called like Deuce.Bigalow.European.Jiggalo.TS.VCD-ANON.tar

its scene released. i won't explain scene to everyone, but if it's seperated by dots and ends with a - with a group name. its likely a more authentic file.