9.1 Introduction

The digitization of analog audio and video signals increases the signals bandwidth. The application of source coding results in a decreased signal bandwidth, and several bit rates can be selected to support the required quality of service. Eventually, the digitally coded signals require less bandwidth than analog signals, with the same quality. The most common standards for the digital coding of audio and video signals are produced by the ISO/IEC JTC1 SC 29 MPEG. This group has specified and upgraded several standards for digital audio-visual coding. In the case of audio, the current standards are known as MPEG layer I to layer IV. For digital video coding, the current standards are referred to as MPEG-1 to MPEG-4.

This chapter discusses the DVB specifications for source coding and additional services. DVB has decided to make use of the MPEG standards for source coding and the multiplexing of audio-visual signals and has thus produced guidelines (not specifications) for implementing MPEG-2 audio, video, and systems in satellite, cable, and terrestrial broadcast applications (ETR 154 ^[1]). These guidelines represent a minimum functionality that all integrated receiver decoders (IRDs) can either meet or exceed. The IRDs that meet these minimum functionalities are called baseline IRDs. All features other than those provided in the guidelines are left to the marketplace.

Additionally, DVB has produced specifications for service information, teletext systems, and subtitling systems. These specifications are standardized by ETSI. First, the basic elements of the systems mentioned above are discussed before explaining...