DVD to mpeg file

I have been tasked (as a favour) to produce a "movie file" from a DVD so that it can auto play (via USB stick) on an in-store display.

I am checking but believe the in store display device will autoplay a movie file.  Checking what type of file but ssume a mpeg will be fairly standard.

So...how do I do this...maintaining best possible IQ  ?  (ie how to get the media off the DVD?)

Thanx for any input.