i have produced a few training DVDs, in which the trainee chooses a clip from a menu and the clip plays continuously until the trainee decides to go back and choose a new exercise. i have been asked to make the DVDs available for portable devices. as far as i know, portable devices do not play DVDs. one option could be to generate a bunch of html for the menus and drive the mp4 clips from there. alternatively, someone has suggested i use http://www.digitalworkshop.com/products/opus-pro.shtml. are these viable options? is there any other option i am not aware of?

thanks in advance