chapter  21
14 Pages

Digital Television

Digital television is being widely adopted for various applications ranging from high-end applications, such as studio recording, to consumer applications, such as digital cable TV and digital DBS (Direct Broadcasting Satellite) TV. For example, several digital video tape recording standards, using component format (D1 and D5), composite format (D2 and D3), or compressed component formats (Digital Betacam) are commonly used by broadcasters and TV studios [1]. These standards preserve the best possible picture quality at the expense of high data rates, ranging from approximately 150 to 300 Mbps. When captured in a digital format, the picture quality can be free from degradation during multiple generations of recording and playback, which is extremely attractive to studio editing. However, transmission of these high data-rate signals may be hindered due to lack of transmission media with an adequate bandwidth. Although it is possible, the associated transmission cost will be very high. The bit rate requirement for high definition television (HDTV) is even more demanding, which may exceed 1 Gbps in an uncompressed form. Therefore, data compression is essential for economical transmission of digital TV=HDTV.