DVD Production

Chapter 2

DVD physical specifications

Comparison with CD

While the surface area of a single DVD layer is the same as that of a CD, technical advances in both optical media and digital processing algorithms give the DVD layer more than seven times greater data capacity. This greater capacity is achieved in part by reducing the size of the ‘pits’ used to mark the data on the disc surface, so that more pits fit in a given area. Increased pit density means more available bits. And with a more efficient error correction scheme, DVD needs to reserve fewer bits for data redundancy, allowing more overall material to be stored on the disc.

Table 2.1 Media specifications of the DVD and CD systems.

	DVD	CD
Disc diameter	120 mm (5 in.)	120 mm ...