[PROBLEM]
An official, national archiving institution had to ingest their DVD collection as ISO image.
The best tool for reading optical media job is "dvdisaster".
Dvdisaster is designed to read optical media in a special way (that's what it's designed and good for), but that's the reason why dvdisaster doesn't use libdvdread. So it can't handle encrypted DVDs, for example.
[SOLUTION]
A video player (like VLC for example), uses libdvdread to descramble the files.
So, if you open an encrypted DVD in VLC, seek to some random position and hit play, then stop again - Dvdisaster is then able to read the scrambled disk, too.
Another example showing how copy protection can cause cultural heritage to become lost - if we aren't able to circumvent it...
Dvdisaster: Read of scrambled sector without authentication
Dvdisaster: Read of scrambled sector without authentication
Jumping out of an airplane is not a basic instinct. Neither is breathing underwater. But put the two together and you're traveling through space!
Placeholder for broken/scrambled sectors
In case a broken (or scrambled) sector is found by dvdisaster, it writes the following string into the extracted disk image (e.g. ".iso") file:
dvdisaster dead sector marker
This sector could not be read from the image.
Its contents have been substituted by the dvdisaster read routine.