ABSTRACT
This chapter focuses on the structure of the moving pictures expert group (MPEG)-2 "transport stream" as one of the better examples of packetization and multiplexing of program material. It investigates what is involved in switching or splicing MPEG-2 packetized data. In addition to the different methods for processing the frames, variable length coding is also applied to the resulting data as a means to improve the efficiency of communications between encoder and decoder. There are two ways to handle transitions between program segments. One is to make the transitions in the raster-based domain — that is, using unencoded or decoded signals. The other is to make the transitions using fully or partially encoded signals. Enhanced delivery for downstream processing is something that has been discussed for quite some time within the Advanced Television community. Speaking of delivery systems, no discussion of packetized transport would be complete without recognizing the role likely to be played by asynchronous transfer mode.
