Blu-ray disc player can play music, but can not play Blu-ray disc?
Most Blu-ray movie discs are encrypted. Music CD ROMs are not. That might explain why a music disc will play but a movie Blu-ray won’t.
how to install Decoding plugin for VLC
FreeBSD ports tree has multimedia/makemkv. It has limitations on BSD compared to other operating systems that is is actually intended for. I don’t think it will help you watch the disc directly but you can make a copy into a mkv file and put your original away for safekeeping. I haven’t followed attempting to play bluray discs in vlc but if I recall it was usually use windows+anydvd or hunt for some non-publicly released libraries (or later alternatives tried to provide a compatible interface?) and provide a file of decryption keys for known discs.
If I recall, in USA it could be deemed illegal to use such techniques to decrypt a disc through DMCA assuming they could claim that purchasing/renting content is not grounds to approve decrypting it. Though if so, it would also be illegal to watch with commercial software/players and using previous mentioned techniques would lead to committing said crimes once per disc instead of once per view of the disc.
Once past that, you can build up an easier to sort and faster to load library, remove the BS like ads and mandatory manufacturer/government messages. Mkv file format has some advanced tricks that could be enjoyed on the files as desired.