So I have a client that wants DRM on a DVD for a promo disc of a documentary... I have a small budget and I've never dabbled in DRM (with DVD's at least)

Google seems to be flooded with Anti-DRM garbage and no real DRM solutions... something open source and simple is enough, I'm not looking for "Maximum Security" unless it can be achieved.

Any suggestions? Client wants to send DVD's out for viewing and have them returned uncopied.