I backup my dvd movies with dvd fab by using the clone mode.When i use clone mode the dvd is exactly the same file size as the original but when i copy it using the full disk mode the file decreases in size. I was wondering why is that? I use full disk mode to change the volume name on the disk.
Why is it when you clone a dvd the file is the same but when you just copy it, the file size lowers?
The answer lies in copy protection, or Digital Rights Management (DRM), which are special mechanisms, algorithms or encryption used on DVDs to inhibit the copying of them by conventional commands. See the last sentence of the quote below.
%26quot; ..CSS, which is used on DVDs, is a famous example of this. It is a form of copy protection that uses 40-bit encryption. Copies will not be playable since they will be missing the key, which is not writable on DVD-R or DVD-RW discs...%26quot;
http://www.webopedia.com/TERM/C/copy_pro鈥?/a>
http://www.zappersoftware.com/copy-prote鈥?/a>
http://en.wikipedia.org/wiki/Copy_protec鈥?/a>
