Decrypting DVD's and DVDFab5

vbimport

#1

I can not find the answer to this in my search thus far so if there is a resource somewhere, please post the link.

When I create an ISO from a DVD, what is being decrypted? I was talking to someone about MythTV and they said the ISO’s that it creates are bit for bit with all the protections/encryption. I was under the impression that there was something that had to be decoded in order to be able to create ISO’s for playback and that any software would need to do what DVDFab is doing for it to work, otherwise, I could just copy the files (VOB’s, etc.) directly off of the disc.

I’m sure I’m missing something in my understanding of DVD’s, copy protection, encryption and the like so I want to correct and broaden my understanding what is going on.

FYI, I purchased the DVDFab5 Platinum w/ mobile in order to make ISO’s for playback via XBMC and to merge 2-part discs into one. I also want to play them back on my WM5 smart phone. It’s working great so far. I have encountered a few where the DVD ISO had an issue and stopped playing in the middle. I had one where about 10 seconds of the audio was missing from the end of one disc, but reconverting to ISO fixed the issues.

Thanks for any feedback.


#2

I’ll try to answer. Commercial DVDs are protected various ways and DVDFab5 removes all of them. The ISO image made by Fab is not protected.

What did I miss?


#3

Look at the Protections page in Common Settings for an idea of what DVDFab removes. The key thing is the CSS scrambling of the video–its undoing is what makes the copied files playable.


#4

Both 90 and signals make great points.
I’ll try to explain it another way.

First off, let’s get the term ripping defined. For purposes of this discussion, simply, it is the process of copying the contents of a dvd. So this is more than just playing or reading a dvd. It includes the process of copying the contents to another target…in this instance a hdd.
If the source disc is copy protected…well then, you can’t simply copy it. You must remove the copy protection or decrypt the source disc . Otherwise, there would be no need for rippers such as Fab, shrink, dvddecrypter, etc., etc. Once the copy protection is removed, that’s it, it’s permanent.

Take a look at the Protections page as suggested by signals.

Fab can create a clone and the end product is an .ISO file. This is a bit for bit copy, but without the copy protection.

For starters:

http://en.wikipedia.org/wiki/DVDFab


#5

Thanks for the info everyone. Can an ISO be a bit for bit if copy protection is removed? I guess that’s where I get hung up.

I have some more reading to do…:eek:


#6

Fengtao, the program’s author, has addressed this a few times. Here is the gist:
*There is no way for a clone to be 100% the same
*In a Clone of a 8GB DL original, maybe 50MB are different
*The VOB files are being decrypted (“de-CSSed”)
Clone mode preserves the original DVD structure, including the layer break. You can even set it not to modify the original IFO files (but then the UOP restrictions will remain).

Here is a thread where some of this was discussed: http://club.cdfreaks.com/2101079-post46.html
There are others, but I didn’t have time to find them. Use advanced forum search for posts by Fengtao with some of these keywords.


#7

Exactly what I was looking for…thanks!!