I assume you are wanting to rip a commercail dvd.
DVD Shrink is very good at making a movie file fit onto a single 4.7GB dvd, but some modern encryption systems seem to defeat it. Try usinf DVD Decrypter (freeware) first to rip the files you need then use DVD Shrink to make the copy. Sme useful info and help guides on DVD Shrink and DVD Decypter here