Sorry if somebody already do this suggestion (But I can't find the same using search)

the Idea is to contact a DVD Decrypter programmer like Smartripper or
DVD Decrypter

and to make a Virtual Decrypted DVD Drive that would "map" a real DVD
Drive (and propose an Api for treating data like decrypting (it is an exemple))

If I put a DVD video in the real drive I can read (With Decripting on
the fly by the Decryptiing engine) decrypted vob on the Virtual Drive
(like the flaskMpeg plugin for reading directly form DVD)

Of course for legal purpose I don't Think daemon-tools must provide the
DVD Decrypter engine
it would be best if We could find Decrypter engine that would be daemon
tools compatible :-)

Else I must say that your program is awesome

good continuation