Dr. Dobb's Journal July 1998

Region Management

Many users have manually modified their DVD player to ignore region management. This process is usually accomplished by setting all the bits (or enabling all regions) in the player's internal region register. This hack initially allowed players to play content from any region of the world. However, content creators have embedded instructions in the DVD discs to validate that the region code of the player is legitimate. If the content detects that the player has an invalid region code, it will refuse to play the movie (see Example 3).

VMG is also the source of a controversial field -- region control. To explain, the DVD specification places artificial limitations on where the disc may be played. If the region code for the player does not match the region code in the content, then the DVD specification will not let the player present the disc -- even though the player can decode the content.

-- L.D.