Why do some discs require side flipping?
Even though DVD’s dual-layer technology allows over four hours of continuous playback from a single side, some movies are split over two sides of a disc, requiring that the disc be flipped partway through. Most “flipper” discs exist because of producers who are too lazy to optimize the compression or make a dual-layer disc. Better picture quality is a cheap excuse for increasing the data rate; in many cases the video will look better if carefully encoded at a lower bit rate. Very few players can automatically switch sides, but it’s not needed since most movies less than 4 hours long can easily fit on one dual-layer (RSDL) side.
