If it's not either an MPEG-1 or MPEG-2 file then what is it now? Techincally it could be an MPEG-4 file, but most people refer to those as AVIs due to the container they're generally stored in.
You can encode any video file to MPEG2 (DVD complaint) bill984 ... I use MainConcept MPEG Encoder to do this myself (usually) Then I'd use TMPGenc DVD Author to convert to VOB (if then over 4.36Gb I would compress w/ either DVD2One or DVD Shrink)