WHAT ARE IFO AND BUP FILES ON A DVD-VIDEO?
IFO Files give the player important navigational information, like where a chapter starts, where a certain audio or subtitle stream is located, etc. This is the reason why it’s only possible to rip certain parts of a movie (like a chapter) with a ripper which can read this files. BUP files are just backup files off the IFOs. As their counterparts they are not encrypted.
