What extension is on the original file? Is it an .avi, .mp4, .mkv, or something like that?
DVD-video consists of mpeg2 video in .vob files, along with .ifo, and .bup files for navigation and all contained in a Video_TS folder.
And no, thirty minutes isn't long for the entire process of conversion plus burning to a disk. For simply burning a 700mb avi file to a disk, yes, that is way too long.