If I make a backup (which I can do with `makemkvcon backup` but can also do through the GUI), it is by default encrypted but contains a `discatt.dat` file with all the information needed to play it. Does `makemkv` provide a way to turn that into a decrypted backup, as with `makemkvcon backup --decrypt`? Iʼm pretty sure you canʼt open non-disc sources with MakeMKV backup function so you canʼt “backup” an encrypted backup to a decrypted one, but maybe thereʼs an option Iʼm missing. Even if I make a loopback device and try to use that as a
What about if I donʼt have the `discatt.dat` file but do have the keys for regular libaacs to read it? This is the more likely case, where a backup was made to ISO or without MakeMKV doing the backup.
If MakeMKV doesnʼt do this, is there some other tool that can, with libaacs (or libmmbd acting as libaacs)? It seems like it should be trivial to make, but I canʼt find anyone who has, and I donʼt know libaacs well enough to do it myself. (EDIT TO ADD: Also libbdplus support would be nice; decrypted MakeMKV backups also handle that it looks like. I found one tool on the Doom9 forums but it seems to reimplement AACS and BD+ functionality in a buggy way and seems to be Windows only.)