For those with experience in the file systems and intricacies of video DVDs I apologize for any ignorance on my part. I just encountered something that got me to thinking, as was hoping someone my be able to point me in the right direction in order to reproduce it.
I've run into a DVD video protection scheme that seems to be somewhat effective in stopping casual users making copies. It is fallible though, and can be bypassed by AnyDVD. None the less, I found myself intrigued by the way in which the DVD are "protected". An unprotected ISO of a video DVD is selected then edited by the program. This produces a slightly larger output ISO which can then be burned normally. This protected ISO seems to contain 99 copies of the original VTS_XX.vob video files, their .BUPs and .IFOs, as well as an edited version of the VIDEO_TS.IFO.
In an attempt to recreate this scheme I manually edited the VIDEO_TS.IFO an original unprotected ISO. This did nothing to slow any modern DVD ripping software, leading my to believe that the brunt of the protection lies in they high number of copies of the original .VOB/.BUP/.IFO files. Each of the 99 video files on the protected ISO all seem to play the same video and larger videos, when protected state the the size of the extracted files will be high above that possible for a DVD disk (10-20gigs).
So my main question to those that have more experience, does this sound like some kind of corruption of the underlying UDF file system? And if so, is it reproducible? Any suggested links/reading material regarding any of these topics would be appreciated as well.
For the curious
Original ISO http://www.mediafire.com/?qvcqefvbuuc9iqb
Protected ISO http://www.mediafire.com/?9aq7p6siu5yacuo