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Ripping an ISO of a disc I own - volume key unknown?

Posted: Thu Feb 08, 2018 3:45 pm
by yonis
I bought a new copy of X-Men Apocalypse in UHD, but encountered I/O errors when reading the disc with MakeMKV. It'll decrypt the disc fine, but then fail to fully rip the disc about a third of the way in.

I was able to extract the data from the disc by painstakingly reading 100 MB chunks of the disc in dd, ejecting and reinserting the disc when I/O errors occurred, then joining the chunks together to an ISO using cat.

I can perfectly browse the ISO in Finder, but when I try to open it in MakeMKV, it complains that the volume key is missing and can't decrypt it.

Code: Select all

MakeMKV v1.12.0 darwin(x64-release) started
The program can't find any usable optical drives.
Using direct disc access mode
Saved AACS dump file as [...]/Library/MakeMKV/MKB20_v61_X-Men_Apocalypse_BE17.tgz
The volume key is unknown for this disc - video can't be decrypted
Failed to open disc
Since I have the disc I ripped the ISO from, how can I get MakeMKV to decrypt the ISO the same way it can with my original disc?

Re: Ripping an ISO of a disc I own - volume key unknown?

Posted: Thu Feb 08, 2018 4:05 pm
by TeddyRaspin
If a VUK for your version is unknown, you have to send first the generated dump to Mike in order to have the VUK added in the keys_hashed.txt file.

Then you will be able to properly decrypt either original disc or protected iso. :wink:

Re: Ripping an ISO of a disc I own - volume key unknown?

Posted: Thu Feb 08, 2018 4:31 pm
by preserve
TeddyRaspin wrote:If a VUK for your version is unknown...
Nope, that's not the issue :)
yonis wrote:It'll decrypt the disc fine, but then fail to fully rip the disc about a third of the way in.
A few people have posted similar issues but I'm not sure if a definitive solution has been found. Could be an issue with the drive, what drive are you using? Debug log?

Re: Ripping an ISO of a disc I own - volume key unknown?

Posted: Thu Feb 08, 2018 8:24 pm
by mike admin
yonis wrote:Since I have the disc I ripped the ISO from, how can I get MakeMKV to decrypt the ISO the same way it can with my original disc?
Yes, if you have made the iso from exactly the same disc, with exactly the same drive on exactly the same firmware version.
You will need to unpack the iso (with winrar, or mount and copy all files from) to a folder #1.
Then you need to start MakeMKV and make a non-decrypted full disc backup, from the same disc and in the same drive, to another folder #2.
The moment MakeMKV starts copying the files, abort the backup, eject the disc, quit MakeMKV.
Copy file discatt.dat from folder #2 to folder #1
Delete folder #2
Folder #1 is now a non-decrypted full disc backup. You can open it in MakeMKV as usual.

Re: Ripping an ISO of a disc I own - volume key unknown?

Posted: Fri Feb 09, 2018 3:35 am
by yonis
mike admin wrote:Yes, if you have made the iso from exactly the same disc, with exactly the same drive on exactly the same firmware version.
You will need to unpack the iso (with winrar, or mount and copy all files from) to a folder #1.
Then you need to start MakeMKV and make a non-decrypted full disc backup, from the same disc and in the same drive, to another folder #2.
The moment MakeMKV starts copying the files, abort the backup, eject the disc, quit MakeMKV.
Copy file discatt.dat from folder #2 to folder #1
Delete folder #2
Folder #1 is now a non-decrypted full disc backup. You can open it in MakeMKV as usual.
Thank you! This worked perfectly!

For what it's worth, I have the Asus BW-16D1HT, 3.02 firmware (updated from 3.0), in a Vantec NST-536S3-BK NexStar DX USB enclosure. I've ripped a few UHD discs with MakeMKV alone, but sometimes these (brand-new) discs produce I/O errors partway through ripping.

I wrote a script to clone segment by segment, and toss any segments with I/O errors in them, reripping just those segments after re-inserting the disc. Happy to know that my hacky workaround can work with MakeMKV!

Re: Ripping an ISO of a disc I own - volume key unknown?

Posted: Thu Mar 08, 2018 5:47 pm
by crackers8199
yonis wrote:
mike admin wrote:Yes, if you have made the iso from exactly the same disc, with exactly the same drive on exactly the same firmware version.
You will need to unpack the iso (with winrar, or mount and copy all files from) to a folder #1.
Then you need to start MakeMKV and make a non-decrypted full disc backup, from the same disc and in the same drive, to another folder #2.
The moment MakeMKV starts copying the files, abort the backup, eject the disc, quit MakeMKV.
Copy file discatt.dat from folder #2 to folder #1
Delete folder #2
Folder #1 is now a non-decrypted full disc backup. You can open it in MakeMKV as usual.
Thank you! This worked perfectly!

For what it's worth, I have the Asus BW-16D1HT, 3.02 firmware (updated from 3.0), in a Vantec NST-536S3-BK NexStar DX USB enclosure. I've ripped a few UHD discs with MakeMKV alone, but sometimes these (brand-new) discs produce I/O errors partway through ripping.

I wrote a script to clone segment by segment, and toss any segments with I/O errors in them, reripping just those segments after re-inserting the disc. Happy to know that my hacky workaround can work with MakeMKV!

can you share your script? i'm trying to salvage an apparently damaged blu ray but not having any luck getting past a certain spot. i was able to get ddrescue to produce an iso and then decrypt it similar to the procedure detailed here, but it still fails at the same spot complaining of corrupted files...

Re: Ripping an ISO of a disc I own - volume key unknown?

Posted: Thu Jan 31, 2019 4:12 am
by dafolsom
I know this is an old topic, but I have been trying for an hour now to figure out how to produce the discatt.dat file as described by Mike in this thread. I have a couple questions that, if answered, might clarify this for me:
  • Is a "non-decrypted full disk backup" any different than the usual process of making a backup?
    At what point in the process does MakeMKV "start copying the files"? While "Saving to MKV file"? While "Saving all titles to MKV files"?
At no point can I see the creation of the discatt.dat file in the destination folder and when I abort the process and close the app. the folder contents are deleted.

Any help would be appreciated. Thanks.

Re: Ripping an ISO of a disc I own - volume key unknown?

Posted: Thu Jan 31, 2019 1:55 pm
by Woodstock
Non-decrypted backup is, "Start a backup, uncheck the "decrypt files" checkbox, and let it run for a moment". Pretty much any time after you start getting messages about writing files, you can stop the backup, and discatt.dat will have been created.

Re: Ripping an ISO of a disc I own - volume key unknown?

Posted: Fri Feb 01, 2019 2:36 am
by dafolsom
Got it! Thanks so much.

Re: Ripping an ISO of a disc I own - volume key unknown?

Posted: Thu Jan 07, 2021 5:52 pm
by nayru
That works for me, at least for then extracting the titles to mkv, but is there a way to decrypt the whole disc and turn it into a decrypted full backup?
Thanks.

Re: Ripping an ISO of a disc I own - volume key unknown?

Posted: Thu Jan 07, 2021 10:06 pm
by dcoke22
http://makemkv.com/faq/item/4

MakeMKV FAQ: How to create decrypted full disc backup (M2TS) ?

Re: Ripping an ISO of a disc I own - volume key unknown?

Posted: Thu Jan 14, 2021 2:34 pm
by chiavere
Hi,

I am unable to decrypt a physical, commercial 4k disc - first time I have seen this error, have ripped many of my other physical discs for mkv backups:

"The volume key is unknown for this disc - video can't be decrypted
Failed to open disc
Using LibreDrive mode (v06.2 id=F046CEB2F3AB)"

How do I get the volume key for this disc?

Thanks!

Re: Ripping an ISO of a disc I own - volume key unknown?

Posted: Thu Jan 14, 2021 3:42 pm
by dcoke22
MakeMKV downloads keys automatically if they are known. Did MakeMKV make a .tgz dump file? Email that to: svq@makemkv.com and the key will eventually be available.

Re: Ripping an ISO of a disc I own - volume key unknown?

Posted: Thu Jan 14, 2021 4:01 pm
by chiavere
dcoke22 wrote:
Thu Jan 14, 2021 3:42 pm
MakeMKV downloads keys automatically if they are known. Did MakeMKV make a .tgz dump file? Email that to: svq@makemkv.com and the key will eventually be available.
Ok, great yes it made a .tgz - will email it,
Thanks!