DVD Region 2 - Doctor Who: City Of Death - Video & DVD

Click Here to Order DVD Region 2 - Doctor Who: City Of Death

Click Here for More Information about DVD Region 2 - Doctor Who: City Of Death.

Did you know

1. A single-layer DVD can store 4.7 Gbyte, which is around seven times as much a standard CD-ROM. By employing a red laser at 650 nm (was 780 nm) wavelength and a numerical aperture of 0.6 (was 0.45), the read-out resolution is increased by a factor 1.65. This holds for two dimensions, so that the actual physical data density increases by a factor of 3.5. DVD uses a more efficient coding method in the physical layer. CD's error correction, CIRC, is replaced by a powerful Reed-Solomon product code, RS-PC; Eight-to-Fourteen Modulation (EFM) is replaced by a more efficient version, EFMPlus, which has the same characteristics as classic EFM. The CD subcode is removed. As a result, the DVD format is 47 percent more efficient with respect to CD-ROM, which uses a "third" error correction layer.

2. Compact discs are made from a 1.2 mm thick disc of polycarbonate plastic coated with a much thinner layer of super purity aluminium (or rarely, gold, used for its data longevity, such as in some limited-edition audiophile CDs) which is protected by a film of lacquer. The lacquer can be printed with a label. Common printing methods for compact discs are silkscreening and offset printing. CDs are available in two sizes. By far the most common is 120 mm in diameter, with a 74-minute audio capacity and a 650-MB data (See storage capacity; this form factor has also erroneously been called "CD5" since it is about five inches across). Such a standard disc weighs 15 grams. They are also available as 80-mm discs, a format which is mainly used for audio CD singles in some regions (e.g. Japan), much like the old vinyl single. Each such "miniCD" or "Maxi CD" can hold 21 minutes of music, or 180 MB of data (this form factor has also been called "CD3", since it is about three inches across). Other unique shapes and smaller form factors have also been sold or given away as promotional items. Examples include Business Card CDs in the shape of a rectangular card, CDs shaped like the map of a country, etc.