Had to rip to iso with ddrescue, have disc and ISO but "volume key is unknown"

[Tom-B]

Hi all,

I have a faulty disc with about 5mb of bad sectors. MakeMKV can't rip it normally as it fails to read the title.

I *was* able to create an iso using ddrescue and lost about 5mb of the 40gb blu-ray. Funnily enough, given the position in the title with the error I'm 90% sure it's the intro sequence that appears the same on all episodes, so I'll be able to recut it with the intro when I do my encode anyway, or a small visual blip durin the intro I can live with.

Trying to load the iso using makemkv gives "The volume key is unknown for this disc - video can't be decrypted" along with an AACS dump file.

Given I have the disc and makemkv can rip it, how can I apply the deception key from the disc to the iso file when loading it through makemkv? I assume this is possible?

I'm assuming that `ddrescue` isn't going to be smart enough to decrypt since it doesn't care about the type of data or contents, but hopefully makemkv is and I can just apply the same key that is used on the disc?

Thanks for your great program!

[Tom-B]

I found the solution on the forum but it didn't solve my issue:

I used makemkv to create an encrypted backup, then deleted the AACS/BDMV and CERTIFICATE folders, mounted the iso created by ddrescue and created symlinks in the backup directory to those on the mounted iso.

Then I used makemkv to open the backup. However, I still get the same issue as I did with the actual disc.

Code: Select all

The source file '/BDMV/STREAM/00022.m2ts' is corrupt or invalid at offset 299298816, attempting to work around
The source file '/BDMV/STREAM/00022.m2ts' is corrupt or invalid at offset 299298816, attempting to work around
The source file '/BDMV/STREAM/00022.m2ts' is corrupt or invalid at offset 299298816, attempting to work around
The source file '/BDMV/STREAM/00022.m2ts' is corrupt or invalid at offset 299298816, attempting to work around
The source file '/BDMV/STREAM/00022.m2ts' is corrupt or invalid at offset 299298816, attempting to work around
Encountered 41 errors of type 'HashCheck Error'

Since it's only 4.8mb of data that's corrupt is there any way to recover the remaining data for the title? It's a 13gb episode, a 5mb missing chunk is going to cause a minor blip in the video for a second!

Is there any way I can increase the number of acceptable hashcheck errors or attempt to rip without error checking at all?

Thanks

[Radiocomms237]

If there is bad data in a source file, MakeMKV will NOT save a corrupt .mkv file, so you can't have a file output that has corruption in only the opening titles, as you wanted.

That's just the way MakeMKV is, it aims for perfection or nothing at all. Yes, that's a real PITA sometimes, as in this case, but that's just how it is and, as far as I know, there's no setting to override it.

The only things I can suggest are "Clean, rinse, repeat" (sometimes a different 'read' or even a different drive yields different results), and failing that I'm afraid a replacement disc may be the only solution?