Switching Facilities in MPEG-2: Necessary but Not Sufficient

MPEG-2 provides a number of facilities intended to permit the time concatenation of separately-compressed program segments. These are intended to permit the assembly and insert editing of programs downstream from their encoding or release points. They furnish, for example, an indicator for where switching can occur and a countdown to the switching point, as well as other such bits of information. These are necessary to support some of the mechanical aspects of switching between segments in the assembly of programs and other continuity elements for release and in the downstream insertion of commercials. — The switching hooks provided in the MPEG-2 Transport Stream packetization, however necessary they may be, are not sufficient to the task. Several operational steps must be taken for continuity integration to succeed in producing a smoothly flowing output without the appearance of a “channel change” at the switching points. Indeed, for the successful integration of material encoded at different facilities, these operational steps must be precisely defined and standardized. — This paper examines the supporting functions provided by MPEG-2 and will suggest a number of areas in which agreement must be reached on operations practices before successful networks can be built.

Published

1995-02

Content type

Original Research

DOI

10.5594/M00828

ISBN

978-1-61482-922-5