Squeezing through the pipe: digital compression 195 program contribution has been restricted to mostly sports and events (although one leading Japanese broadcaster has been newsgathering in HD for several years). The future of HDTV use in SNG therefore undoubtedly lies in the use of new compression and mod- ulation techniques, such as MPEG-4 AVC and DVB-S2, which we will examine shortly. These will moderate the excessive bandwidth demands using MPEG-2 and QPSK. 4.7 DVB and MPEG-2 In Chapter 3, we discussed the option of `multiplexing' two program paths (or `streams') in the digital domain by cascading two digital compression encoders together to provide a single digital data stream to the uplink chain. The MPEG standard defines the method of multiplexing and program-specific information (PSI) tables which enable the individual `packetized elementary streams' (PES) to be trans- mitted and decoded correctly. The European DVB (Digital Video Broadcasting) standard has enabled this to be implemented in a transmission process for the consumer that can be used by manufacturers to produce equipment that will interoperate between manufacturers. The DVB project was officially inaugurated in 1993, born out of the European Launching Group for Digital Video Broadcasting initiative. The project consists of a voluntary group of more than 200 organ- izations that have joined forces to develop standards for DVB. The MPEG-2 standard has been adopted as the DVB compression standard for broadcast distribution and transmission, and part of that standard covers the combining of program streams.