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4K UHD BD Copy
Posted: Wed Nov 17, 2021 1:38 am
by luckiestone
I've got two new 4K UHD BD writers, and tested them with some 4K UHD BD cloning, and I got some questions here.
One writer is LG BU40N with friendly firmware which is a so called UHD-Friendly drive and capable of both playing back and cloning UHD discs. I've successfully used this BU40N backed up an BD100 UHD disc.
Another writer is Pioneer's new released BDR-XD08MB-S, an official UHD drive, which is not a "friendly" one, and of course MakeMKV can not use the drive to clone UHD disc.
However, I found that I can fully read and copy the folder contents of the AACS2-protected UHD disc in Win10 explorer, I copied them out to my HDD and of course it's encrypted. But I thought AACS2 is copy-protected, why can I still copy it out, and why MakeMKV can not? Is it possible for MakeMKV or something alike to copy it out with "unfriendly" drive similarly in win10 explorer and then decrypt it separately, in this way more drives would be supported. Is it normal that Win10 shows and copies contents of protected 4K disc using an unfriendly official UHD drive like Pioneer BDR-XD08MB-S?
Re: 4K UHD BD Copy
Posted: Wed Nov 17, 2021 3:54 am
by Billycar11
luckiestone wrote: ↑Wed Nov 17, 2021 1:38 am
I've got two new 4K UHD BD writers, and tested them with some 4K UHD BD cloning, and I got some questions here.
One writer is LG BU40N with friendly firmware which is a so called UHD-Friendly drive and capable of both playing back and cloning UHD discs. I've successfully used this BU40N backed up an BD100 UHD disc.
Another writer is Pioneer's new released BDR-XD08MB-S, an official UHD drive, which is not a "friendly" one, and of course MakeMKV can not use the drive to clone UHD disc.
However, I found that I can fully read and copy the folder contents of the AACS2-protected UHD disc in Win10 explorer, I copied them out to my HDD and of course it's encrypted. But I thought AACS2 is copy-protected, why can I still copy it out, and why MakeMKV can not? Is it possible for MakeMKV or something alike to copy it out with "unfriendly" drive similarly in win10 explorer and then decrypt it separately, in this way more drives would be supported. Is it normal that Win10 shows and copies contents of protected 4K disc using an unfriendly official UHD drive like Pioneer BDR-XD08MB-S?
no its double encrypted now once from the disc and now once from the drive buss encryption to your hdd so it cant ever be decrypted
Re: 4K UHD BD Copy
Posted: Wed Nov 17, 2021 5:06 am
by luckiestone
Billycar11 wrote: ↑Wed Nov 17, 2021 3:54 am
luckiestone wrote: ↑Wed Nov 17, 2021 1:38 am
I've got two new 4K UHD BD writers, and tested them with some 4K UHD BD cloning, and I got some questions here.
One writer is LG BU40N with friendly firmware which is a so called UHD-Friendly drive and capable of both playing back and cloning UHD discs. I've successfully used this BU40N backed up an BD100 UHD disc.
Another writer is Pioneer's new released BDR-XD08MB-S, an official UHD drive, which is not a "friendly" one, and of course MakeMKV can not use the drive to clone UHD disc.
However, I found that I can fully read and copy the folder contents of the AACS2-protected UHD disc in Win10 explorer, I copied them out to my HDD and of course it's encrypted. But I thought AACS2 is copy-protected, why can I still copy it out, and why MakeMKV can not? Is it possible for MakeMKV or something alike to copy it out with "unfriendly" drive similarly in win10 explorer and then decrypt it separately, in this way more drives would be supported. Is it normal that Win10 shows and copies contents of protected 4K disc using an unfriendly official UHD drive like Pioneer BDR-XD08MB-S?
no its double encrypted now once from the disc and now once from the drive buss encryption to your hdd so it cant ever be decrypted
Thank you, and can I understand it this way: every UHD drive can read and copy the contents, but the contents in the UHD disc is encrypted in a way that only can be decrypted directly from UHD disc without coping first, once it's copied without decryption it will double encrypted automatically and will no longer be decrypted.
Re: 4K UHD BD Copy
Posted: Wed Nov 17, 2021 3:39 pm
by SamuriHL
Not exactly. The majority of the content of the disc is encrypted with AACS. All the m2ts files, etc. Upon detecting this encrypted content, the drive's firmware will add another layer of encryption while transferring the data. That's bus encryption. LibreDrive disables that part with an in memory firmware update. However, if you just transfer the contents of the disc without activating LibreDrive or using a process that knows how to get the bus decryption key and decrypt the bus encrypted AACS protected content, then as mentioned it will be double encrypted and irrecoverable. It's a bit confusing, I realize, but that I think was the point when they created this stuff.
Re: 4K UHD BD Copy
Posted: Thu Nov 18, 2021 2:25 am
by luckiestone
SamuriHL wrote: ↑Wed Nov 17, 2021 3:39 pm
Not exactly. The majority of the content of the disc is encrypted with AACS. All the m2ts files, etc. Upon detecting this encrypted content, the drive's firmware will add another layer of encryption while transferring the data. That's bus encryption. LibreDrive disables that part with an in memory firmware update. However, if you just transfer the contents of the disc without activating LibreDrive or using a process that knows how to get the bus decryption key and decrypt the bus encrypted AACS protected content, then as mentioned it will be double encrypted and irrecoverable. It's a bit confusing, I realize, but that I think was the point when they created this stuff.
Thanks for you informative comments, and this gives me a better understanding of that so called "copy-protected", that does not mean one can't copy the contents out, AACS designed to kind of destroying the original contents once it's copied all copied out, at least by now, are some random bits.
Re: 4K UHD BD Copy
Posted: Thu Nov 18, 2021 3:24 pm
by SamuriHL
This is why when LibreDrive is active, you can read the entire contents of the disc just fine. Granted, it'll still have the AACS encryption in place until you let MakeMKV decrypt it but you can at least read the contents without it getting bus encrypted. This is VERY helpful for those of us that activate LibreDrive and then open ImgBurn and create a protected ISO image from the disc. If you did that without LibreDrive active, then the contents of the ISO would be completely useless. But with LibreDrive enabled, bus encryption is turned off, and the contents of the disc become available to be read. Bus encryption was "improved" in the AACS 2.0 standard. It's annoying. LOL But LibreDrive makes it much less painful.
Re: 4K UHD BD Copy
Posted: Fri Nov 19, 2021 2:40 am
by luckiestone
SamuriHL wrote: ↑Thu Nov 18, 2021 3:24 pm
This is why when LibreDrive is active, you can read the entire contents of the disc just fine. Granted, it'll still have the AACS encryption in place until you let MakeMKV decrypt it but you can at least read the contents without it getting bus encrypted. This is VERY helpful for those of us that activate LibreDrive and then open ImgBurn and create a protected ISO image from the disc. If you did that without LibreDrive active, then the contents of the ISO would be completely useless. But with LibreDrive enabled, bus encryption is turned off, and the contents of the disc become available to be read. Bus encryption was "improved" in the AACS 2.0 standard. It's annoying. LOL But LibreDrive makes it much less painful.
And this explains why two ISO's ImgBurn cloned with my two different drives hava different hash values.
Re: 4K UHD BD Copy
Posted: Fri Nov 19, 2021 2:46 am
by SamuriHL
Yes indeed. And they shouldn't be different. IOW, with LibreDrive enabled to remove bus encryption, the results should match because it's reading the raw data off the disc. With bus encryption enabled, yea, it'll be different every time you read it.