Hi Stanley
I don't know about the movie files but I have used hymn -- decrypt iTunes and iPod music / unprotect AAC files (m4p --> m4a) in the past and it has worked for me. I used it after I purchased some iTunes songs with a giftcard, then found out after I reformatted my harddrive - I could only reload it on my computer 5 times.
The software worked for me and is free.