Directory Structure for Backup

[mugz8391]

I found a thread where this question was asked back in 2014, but the answer was never given.

When backing up a Blu-Ray, MakeMKV creates an extra directory that is not in the normal Blu-Ray directory structure, named "MakeMKV" - I have noticed that ISO images created with this additional directory can cause VLC to crash. I went back and simply deleted this directory and and used ImgBurn to re-create the ISO and the VLC crash problem goes away and the image seems to work fine.

It would appear that this additional MakeMKV directory that appears in the tree when creating a backup is not necessary and can cause some players to fail.

Is there a reason for this directory to be there and if so what is its purpose?

[mike admin]

This directory is created only mostly when using decrypted backup.

MakeMKV rule is that the backup (encrypted or decrypted) is as good as original disc. However original disc contains more data than just files, and for this reason MakeMKV has to save this data somehow.
On non-decrypted backups MakeMKV creates a single file called discatt.dat where it saves all disc attributes.
On decrypted backups MakeMKV creates a MAKEMKV folder where it puts all data it either deleted from the disc (like AACS directory) or files that describe additional metadata destroyed during decryption.
Having discatt.dat and/or MAKEMKV folder, MakeMKV can always create a virtual copy of an original disc out of a backup. One scenario when it is needed is a BD-java emulation, where java code explicitly checks if files are decrypted (and MakeMKV reconstructs encrypted files as they were on original disc).

You certainly shouldn't burn MAKEMKV folder to the disc.

[Johnnyd]

Thank you mike for explaining this.

I have a question though. You said "Having discatt.dat and/or MAKEMKV folder, MakeMKV can always create a virtual copy of an original disc out of a backup."

But I don't see any options in MakeMKV to do anything at all with the discatt.dat and MAKEMKV folder.

It sounds like you're saying that MakeMKV can recreate a copy of the original disc using the MAKEMKV folder by re-encrypting all the files in the BDMV folder, restoring the files from the MAKEMKV folder, and restoring the data from the discatt.dat file. But I would assume that restoring the data in the discatt.dat file would require burning a disc.

I would appreciate very much if you could provide instructions on how to use MakeMKV to "create a virtual copy of an original disc out of a backup". Please also clarify for me what exactly it is that MakeMKV is creating, such as a burned disc, an ISO, or a new set of files.

[pesos]

bump - would love to know this too. wondering if at some point i could make isos out of my decrypted backup folders.

also, is there some way to make an MKV from the decrypted backup folder?

[Billycar11]

bump - would love to know this too. wondering if at some point i could make isos out of my decrypted backup folders.

also, is there some way to make an MKV from the decrypted backup folder?

yea you can make isos out of them just put it in img burn and do folder to iso

yeah open makemkv file>open files, then go to the backup folder then the bdmv folder then use the index file it will then open in makemkv and show you the playlist and the audio video options to makemkv an mkv

[jemima]

I wondered. When one has already decrypted the BluRay structure (i.e. MakeMKV backup with decrypt checked), shouldn't BD+ and BDJ be gone by then and shouldn't one have a plain M2TS stream that one can play back with anything?

[Billycar11]

I wondered. When one has already decrypted the BluRay structure (i.e. MakeMKV backup with decrypt checked), shouldn't BD+ and BDJ be gone by then and shouldn't one have a plain M2TS stream that one can play back with anything?

No some discs have many m2ts files split apart for reordering and extended cuts and stuff
The movie is all there but In many files

[jemima]

And for playing the right (although already decrypted) files in the right order BD+/BDJ s still needed?

[Billycar11]

And for playing the right (although already decrypted) files in the right order BD+/BDJ s still needed?

it would no longer be functional from what i understand it would pick the wrong playlist if it was an obfuscated title.
but movies just with extended and regular cuts would likely still work.
you just need a player that can use menus like jriver or vlc just be sure to use the open disc bluray function or it can hang

[jemima]

Interestingly, I have two BluRays that use (according to MakeMKV) BD+ (I have none with BDJ), one with "AACS v18, BD+ v2010.9", the other with "AACS v16, BD+ v2010.3".

Playing back an unencrypted backup (made via MakeMKV) of them (with just mpv, KEYDB.CFG, libaacs but no libbdplus) fails… as expected. But playing back a decrypted backup (also made via MakeMKV) works.
So it seems at least for BD+ MakeMKV is able to give me a backup of the BluRay structure (i.e. no .mkv file) which I can playback without libbdplus (which I rather don't want to install, as I don't like any untrusted code being executed).

Hmm… I assume there is no specification about discatt.dat?