Have you tried using Handbrake for the conversion to m4v? It's free. You can also convert to avi and save hard drive space. To rip DVDs I use dvdshrink a lot (even though it's old and unsupported at this point). I rip to .ISO normally (since I archive the .ISO to a server). If it's one that dvdshrink can't handle, I use DVD Decrypter to rip it.