This page describes the evil parts of the DVDVideo specification.
Macrovision is a technique for committing unholy fiddles on an analog video signal in a way that doesn't affect TVs trying to show the picture, but does confuse video recorders trying to make a copy of it.
The circuitry for committing acts of Macrovision is built into all DVD players. It can be enabled by setting a bit in the .VOB file. However, before setting this bit, you have to pay a licence fee to Macrovision Corp.
Store-bought DVDs are commonly encrypted with CSS as a CopyControl measure. The encryption keys are stored in a special part of the disc that can only be accessed via a special handshake between the software and the drive, knowledge of which is only disclosed to those who sign an NDA with the DVD Copy-Control Association. Mass-market DVD writers cannot create discs containing this special key area.
One page links to DVDVideoEvils:
