Why would you need to use DVDFab? Are you trying to convert the mp4 to DVD-video?
If your player is new enough to work with mp4 files, you can burn as data without conversion. If you need DVD-video, then yes, you would need to convert. Every conversion reduces quality and the existing bitrate is fairly low as is for HD video.
I'm hoping that the actual frame rate is 23.976, else things are going to get a bit jerky.
This is all the advice I can give in the DVDFab forum. If you want to ask a similar question in the Video Editing forum, I can give some options.