Of course yes. Many burner software programs will convert for you. They will convert the video file to mpeg2 VOB audio & video.
If your DVD's do not have VOB files on them, then they were not burnt in dvd video format obviously. Probably as data format.
If you open a dvd disk up you find two folders, AUDIO_TS (usually empty but some players still need to see the folder) & VIDEO_TS. Within the VIDEO_TS folder will be your VTS_01_1, etc. files.
* Oh sorry I edited my post above late, you perhaps didn't see my last points I made.