Mismatching ISO files from same DVD video disc

[Ken852]

Hello,

I understand if it's taboo to discuss DVD Decrypter on this forum, and I apologize if it's strictly forbidden to even mention it. But my question is really about ImgBurn rather.

I recently hit a road block as I was imaging my collection of optical media for archival purposes. At one point, when I inserted a DVD video disc, ImgBurn revealed that the disc had copyright protection on it.

I tried to ignore this warning and continue anyway, but ImgBurn did not work correctly and was unable to read the disc at all. So I turned my attention to alternative software, including DVD Decrypter and Any DVD.

I have found one DVD video disc ("The Others" thriller film from 2001) that does not appear to have any copyright protection on it (DVD Shrink also calls it "Not Encrypted"). So ImgBurn is able to read and image this disc without giving me a hard time. However, when I use other software to image the same disc, I get mismatching ISO files.

ImgBurn

Size: 7.54 GB (8,096,284,672 bytes)
MD5: 7135BF384C5E666AAE6873EB3FF33D98

DVD Decrypter

Size: 7.54 GB (8,096,284,672 bytes)
MD5: BF6B0935CBC9D13FA8C6523A34F8B123

Any DVD

Size: 7.54 GB (8,096,284,672 bytes)
MD5: BF6B0935CBC9D13FA8C6523A34F8B123

The resulting files do match by size, but not by hash value. I'm curious as to why that is? What's interesting or odd is that the hashes do match between DVD Decrypter and Any DVD, but the two don't match against what I'm getting out of ImgBurn. So is ImgBurn somehow reading the contents wrong? I did not get any errors or warnings in the log, not for this video disc. All three output files can be mounted and played back on my PC.

 

Edited April 4, 2021 by Ken852

[LIGHTNING UK!]

The other two could still be modifying the contents of the disc as it’s being read. ImgBurn won’t be.

You’d have to do a file comparison and see what's different between the two (three).

[Ken852]

I managed to turn the MD5 hash BF6B0935CBC9D13FA8C6523A34F8B123 from Any DVD into 7135BF384C5E666AAE6873EB3FF33D98 which is the same MD5 hash that the image I made with ImgBurn has. I simply disabled a number of features within Any DVD and made a new ISO image. I'm not sure what exactly triggered it, I will have to do more testing to narrow it down. But it does support the hypothesis that Any DVD (and most likely DVD Decrypter as well) changes the content in some way. I have not done any closer comparison between the ISO images.

 

Edited April 4, 2021 by Ken852

[Ken852]

Testing is done and the results are in.

Assuming that 7135BF384C5E666AAE6873EB3FF33D98 is the hash value for unchanged image (as made by ImgBurn), then the same can be had with Any DVD by disabling the removal of following features in Video DVD - Settings.

• Software Region Code
• Hardware Region Code
• Region Code Scripts
• Analog Protection System
• Prohibited User Operations
• PC-Friendly
• Copy Protection based on unreadable Sectors

All of these are enabled by default in Any DVD, which results in BF6B0935CBC9D13FA8C6523A34F8B123 value when imaging the disc using either one of the two programs, Any DVD or DVD Decrypter. In other words, Any DVD interferes with operation of DVD Decrypter. Same results can be had with DVD Decrypter. It changes what is in fact a "Region 2" disc and makes DVD Decrypter detect it as a "Region 1, 2, 3, 4, 5, 6, 7, 8" (any region) disc. See screenshots of DVD Decrypter below for comparison.

In the screenshots above, you are looking at the images made by ImgBurn as they appear in DVD Decrypter when attached to a virtual drive (Virtual CloneDrive), with Any DVD inactive (first screenshot) vs. Any DVD active in the background (second screenshot). I have used a virtual drive to speed up the reading and testing process.

So one way to get around this and to get the same results with DVD Decrypter is to simply inactivate or exit out of Any DVD when using DVD Decrypter. In addition, to get the same hash value as with Any DVD, you have to disable the option "Remove IFO RC Protection" in DVD Decrypter.

This has made me wonder, what does " Remove IFO RC Protection" do?

It's not enough to just inactivate Any DVD. You only do that to make DVD Decrypter detect the disc properly as a Region 2 disc which it is. But you also have to disable this "Remove IFO RC Protection" option, or in other words you have to NOT remove IFO RC Protection. That way you will get 7135BF384C5E666AAE6873EB3FF33D98  value, same as with ImgBurn.

Any DVD is somehow able to simulate as if the inserted disc is an all region disc. It appears to be triggered by the Software Region Code option. DVD Decrypter doesn't seem to have any such option.

To get BF6B0935CBC9D13FA8C6523A34F8B123 (touched)
Using Any DVD:
Default settings (simulates Region 1, 2, 3, 4, 5, 6, 7, 8)

Using DVD Decrypter:
Default settings (Remove IFO RC Protection: ON)
Any DVD active (simulates Region 1, 2, 3, 4, 5, 6, 7, 8)

To get 7135BF384C5E666AAE6873EB3FF33D98 (untouched)
Using Any DVD:
Remove DVD Video features: none selected

Using DVD Decrypter:
Remove IFO RC Protection: OFF
Any DVD inactive (Region 2) OR active but no DVD Video feature removed

(Failure to turn Remove IFO RC Protection OFF results in hash 03BAB370EB2D46CE327E0D7C092D756B, as opposed to BF6B0935CBC9D13FA8C6523A34F8B123.)
 

[dbminter]

It might make some sense that the AnyDVD and DVD Decrypter ISO's might be "different" than the ImgBurn one.  Both those applications can remove the Macrovision copy protection analog flag.  Thus, the ISO would be different contents because they've been processed.  ImgBurn doesn't do anything with copy protection. 

[Ken852]

I thought so too. But the disc I'm using for testing ("The Others" original from 2001) does not appear to have any sort of copyright protection. ImgBurn for example does not complain about "CSS/CPPM" when I insert the disc, like it does with the other discs when I insert those. The only kind of restriction it does have is Region 2 restriction, as far as I can tell.

There is the option "Remove Macrovision Protection" under the General tab in DVD Decrypter.

It's ON by default, and turning that OFF has no effect on the ISO file I get. Presumably because there is no Macrovision to remove.

As long as DVD Decrypter detects the region code of the disc correctly (Region 2), settings can be left on default with exception for "Remove IFO RC Protection" which needs to be OFF, the ISO file will be identical to that made in ImgBurn. And to detect the region code correctly, Any DVD needs to be either uninstalled, inactivated or at very least its "Software Region Code" option needs to be set to OFF.
 

[Ken852]

I haven't used DVD Decrypter much, almost not at all. I never had a need for it, not until now. I wouldn't know how to check to see whether a disc has Macrovision protection on it or not.

Also, each time I exit out of DVD Decrypter it prints out the following error messages.

After I click to close the program it displays the first message 1 time, followed by the second message 1 time, followed by first message 6 times. I don't know what it's blabbing about, but none of this seems to affect the quality of the ISO files it produces. It's just annoying.

I suspect the number of times it displays the first message has to do with the number of drives in the system (I have a few mounted network drives here). Also, the same messages will appear if I run DVD Decrypter in a VM with Windows 7, but not in a VM with Windows XP. So any Windows version above Windows XP will produce these errors on exit, but it does not seem to affect the image quality, as they are identical to those made with ImgBurn (given the right amount of tweaking the settings).

I must say, it's quite impressive to see such an old program still doing quite well on a modern operating system.

 

Edited April 7, 2021 by Ken852

[LIGHTNING UK!]

It errors out like that because it predates UAC and used to be able to write to HKLM in the registry. Now it can’t. Run as admin and you won’t get the errors.... or ignore them as you have been doing.

iFO RC is IFO file region code. It’s just a byte in the file where you can set which region the disc is for. That’s in addition to the regional code the disc itself might have.

[dbminter]

I figured it had something to do with DVD Decrypter's age and trying to write to Registry entries.

[Ken852]

Thanks for clarifying LUK. Another option would be to disable a few options.

On the Registry tab in DVD Decrypter settings, you can remove the following checkboxes.

Under "Shell Extensions":
"AutoPlay (XP / Server 2003)"
"DVD (Me / 2000 / XP Server 2003)"

Under "File Associations":
CDR, DVD, IMG, ISO, MDS

All of these are enabled by default, and disabling all of them will prevent DVD Decrypter from attempting to write to the Windows Registry.

This is a tip that @dbminter shared with me in a PM and it worked wonders. Thanks to both of you!

 

[LIGHTNING UK!]

I was going to mention that but I couldn't be sure it didn't then try and remove them... which might have caused the same problem! 

[dbminter]

Yeah, I was going by my decidedly ancient memory (16 years.) that there were those options or something similar in the program that might be attempting Registry writes.  Given the age of the application, the code to write Registry entries might not be up to date enough for modern Windows versions.  I'm glad my memory was right and helped in this situation.