The ISO moving picture standardization process started in 1988 with a strong emphasis on real-time decoding of compressed data stored on digital storage devices (DSM) such as CD-ROMs. That allowed for the possibility of a much more complex encoder which did not need to run in real time. The technical work for that MPEG effort was nearly complete (although the official standardization procedures required much more time) when a new project was started to target higher bits rates and better quality for applications such as broadcast TV. The two projects then became known as MPEG-1 and MPEG-2. An MPEG-3 project was anticipated to be aimed at HDTV, but MPEG-2 was shown to be capable of filling that need and MPEG-3 never occurred. For very low bitrates, a fourth project, MPEG-4, was started. However, MPEG-4 has now developed into a generic coding technique that is not limited to low bitrates.

This chapter points out some of the milestones in the development of these MPEG standards, especially the parts of MPEG dealing with video. The audio and systems subgroups usually met concurrently with the video subgroup, but they both had extra meetings that are not detailed in this chapter.