Not a video expert either but those files are part of a video type cd format. They are not files like Marys_1st_birthday.mov and alike. Some video app created that dvd, as such you need an app to to move it to the usb drive.
When you play the dvd in the Mac does the app that plays it have an option to save it to a different location? If not you need to search for an app that will do that. Preferably a free one.
Check some Mac forums and see what they suggest.
Good luck.
