ABSTRACT
This chapter employs moving pictures expert group (MPEG)-2 as a model for looking at packetization because it is so well defined and is likely to see very widespread use. The MPEG-2 systems layer supports two different methods for connecting encoders to decoders, namely the program stream and the transport stream, intended for different types of applications. The eight functions of a Transport Stream packet header are: a sync byte, a transport error indicator, a PES packet-start indicator, a transport priority indicator, program identification — PID, transport scrambling control indicator, adaptation field control, and continuity counter. The Program Map Tables provide the mapping between program numbers and the elementary streams that comprise them. The actual process of splicing program segments takes place in a system with the functionality. The Packetized Elementary Stream (PES) packets for the program to be switched must be extracted from the input Transport Stream by demultiplexing the PIDs identified by the Program Map Table.
