I believe OP means 'any', not a particular one, from Title: "a blu-ray ripper".
Although it may be a user-created dvd, it's likely a commercial movie, with restricted rights.
I agree with #2, and suggest OP spend some time studying LQ Rules and FAQ,
which covers 'search the web first, before posting'.
Here's an obvious web-search: blu-ray ripper on linux
(but don't attempt to discuss anything of questionable legality; LQ has wonderfully high standards!)
Welcome to LQ sophialiu; sorry your 1st post didn't turn out well; come back & try again!
Best wishes!