Specifies the system layer of the coding. It was developed principally to support the combination of the video and audio coding methods defined in Parts 2 and 3 of ISO/IEC 13818. The systemlayer supports five basic functions:1) the synchronization of multiple compressed streams on decoding;2) the interleaving of multiple compressed streams into a single stream;3) the initialization of buffering for decoding start up;4) continuous buffer management; and5) time identification.An ITU-T Rec. H.222.0 | ISO/IEC 13818-1 multiplexed bit stream is either a Transport Stream or a Program Stream.Both streams are constructed from PES packets and packets containing other necessary information. Both stream typessupport multiplexing of video and audio compressed streams from one program with a common time base. TheTransport Stream additionally supports the multiplexing of video and audio compressed streams from multipleprograms with independent time bases. For almost error-free environments the Program Stream is generally moreappropriate, supporting software processing of program information. The Transport Stream is more suitable for use inenvironments where errors are likely.An ITU-T Rec. H.222.0 | ISO/IEC 13818-1 multiplexed bit stream, whether a Transport Stream or a Program Stream, isconstructed in two layers: the outermost layer is the system layer, and the innermost is the compression layer. The systemlayer provides the functions necessary for using one or more compressed data streams in a system. The video and audioparts of this Specification define the compression coding layer for audio and video data. Coding of other types of data isnot defined by this Specification, but is supported by the system layer provided that the other types of data adhere to theconstraints defined in 2.7.

INCITS/ISO/IEC 13818-1-2000 (R2008)