Does AnyDVD use content hashes to comfirm data accuracy?

[Dlk25]

Hey,

I feel like this must have been answered somewhere before but when I look through old threads I can’t see it explicitly answered and some answers seem to imply “no” but then some of those threads are now 6 years old so I want to check again.

If I use makemkv whenever it is ready a blu ray or UHD blu ray it will use the content hashes on the disc to check that the data it has read off the discs is correct (ie. To make sure that the drive didn’t silently read garbage and not throw an error). Makemkv does this regardless of whether I choose to make a decrypted backup or not.

Does AnyDVD do the same? I really just want to be sure that I can rely on my backups being “good” backups of the data in case discs are damaged or degrade. I feel like using makemkv I can be confident that the data I have read matches the data on the disc but I just want to be sure for AnyDVD.

I’ve seen threads were people said “there are checks” for unencrypted images but for encrypted images you need to rip it twice and do a hash comparison. However in makemkv it says it is comparing against the hashes regardless of what the final format of the disc backup.

I actually couldn’t find anywhere in those old threads where anyone explicitly said that the checks are done against the actual hashes that are on the disc.

Again, really sorry if this is somewhere and I’m asking a repeat question but all the threads I found were really old and weren’t actually very clear.

I kinda presume that given the hashes are there and can be used for this then it would be obvious that anyDVD is also using them but again, didn’t want to assume.


Thanks

Dan

 

[DeepSpace]

As for checking the hashes manually, check this thread (the tool comes up at the end):

Resolved - Different hashes for the same disc

As promted, I create a new thread for it. https://forum.redfox.bz/threads/list-of-uhds-currently-un-supported-in-anydvd.76597/post-619784 You should open a new troubleshooting thread, with logfiles and the whole story... True, but there is no story. I just ripped it three times by now, with...

forum.redfox.bz

Then I have seen something about this in the changelog:
8.6.7.0 - New (Blu-ray & UHD): Check, if protected disc / iso is corrupt

If you take a look at this thread, the user got ERROR: Invalid content hash! Disc is corrupt!

So there is something in place now, but I can't remember if there were any more details on this.

 

[Dlk25]

As for checking the hashes manually, check this thread (the tool comes up at the end):

Resolved - Different hashes for the same disc

As promted, I create a new thread for it. https://forum.redfox.bz/threads/list-of-uhds-currently-un-supported-in-anydvd.76597/post-619784 You should open a new troubleshooting thread, with logfiles and the whole story... True, but there is no story. I just ripped it three times by now, with...

forum.redfox.bz

Then I have seen something about this in the changelog:
8.6.7.0 - New (Blu-ray & UHD): Check, if protected disc / iso is corrupt

If you take a look at this thread, the user got ERROR: Invalid content hash! Disc is corrupt!

So there is something in place now, but I can't remember if there were any more details on this.

Ok thanks. Yeah, I have seen lots of discussions about doing multiple rips and manually hashing but was hoping to avoid all that.

I use pioneer drives and I don’t think they are really known for silently returning garbage…have seen more people complaining about LG. But just be good to know the hashes are being checked as it seems like a simple way to be sure you got what you were supposed to get off the disc.

Thanks. I’ll take a look at that change log.

 

[DeepSpace]

Yes, Pioneer drives seem to be good.
I never did manual hashes but as you can see on my thread, one of my drives seems to be less exact. And with the program described in the thread, I just have to scan the .isos once instead of doing multiple rips. I already found several broken images, but I am not nearly done yet. But also, I did take a break for a while now (several months I think).

 

[Dlk25]

If I read that other thread from back in 2018 @James explicitly says he isn’t checking content hashes because it would be hard to do as would need to be done in driver. He says he will think about whether he can implement.

I agree not so important for realtime but for backups I think it’s important.

Did this feature get added? I specifically care about decrypted images and ate the content hashes being checked.

 

[DeepSpace]

This is from 2018, long before my thread and the changelog. But maybe James can clarify again what exactly it does.

 

[James]

If I read that other thread from back in 2018 @James explicitly says he isn’t checking content hashes because it would be hard to do as would need to be done in driver. He says he will think about whether he can implement.

I agree not so important for realtime but for backups I think it’s important.

Did this feature get added? I specifically care about decrypted images and ate the content hashes being checked.

Yes and no. AnyDVD uses random content hash checks to verify correct bus decryption and overall "goodness" of a protected image or disc during mounting. It does not check the hashes during a complete rip. This is a design problem, as the driver decrypts the content in real-time and the ripper only sees decrypted files.
But if you rip to unprotected image, it will check for correct decryption and will throw a verification error.
If there is a bit error the whole group of 3 sectors will be scrambled when decrypted, so I consider this a safe check.

 

[Dlk25]

Thanks for the info.

Ok, so basically if I am reading unprotected/decrypted images from blu ray/UHD blu ray I should be confident that there are no bit errors.

I am pretty sure the answer is no but, for DVD, are there any automated checks? I presume the only way is to do 2 rips and hash them?

 

[James]

I am pretty sure the answer is no but, for DVD, are there any automated checks?

If you rip to folder instead of image the disc is always remastered, so fatal errors should cause the process to stop. But subtle errors might get unnoticed. There will be no checks when creating an image.

 

[DeepSpace]

Good to know. But doesn't matter for me since I will check all isos anyways.