pixels-by-144 lines) applications. Formal plans to pursue MPEG-4 were approved by unanimous vote of the ISO/IEC JTC1 in Brussels, Belgium in September 1993. A draft specification was delivered 1997, and was approved in December 1999. In addition to videophones, MPEG-4 enables interactive mobile multimedia, remote sensing and sign language captioning. In 1995, MPEG became virtually assured of dominance as a standard when Microsoft announced plans to bundle software MPEG-1 playback technology with its operating system, and Compaq announced that it would ship a motherboard with a hardware- based implementation of MPEG. In 1996, both IBM and LSI Logic announced large price reductions because of reduced number MPEG encoding chipsets. MPEG-2 is used for real time high-quality applications (e.g., digital-cable distribution systems and satellite broadcasts). MPEG Family of Specifications Forward Prediction Figure Appendix B-1. Forward Prediction (Michel Bayard). MPEG PICTURE CODING MPEG manipulates motion video as image sequences. An image is divided into macroblocks. MPEG syntax identifies the three approaches that are used to code these macroblocks. MPEG manipulates motion video as image sequences. As such, a great deal of redundancy exists between frames. To achieve temporal compression, it is useful to compute some frames from other frames. Hence, MPEG defines three types of frames. The most basic type is the Intraframe or I-frame. I-frames are compressed using intraframe encoding (DCT). In addition there are Predicted frames (P-frames) and Bi-directional frames (B-frames). I -frames are coded without reference to past or future frames and contain explicit information about every pixel in the image. I-frame coding generates significant amounts of data. A certain number of I-frames must be sent in an MPEG sequence (once every 400 ms is typical) to eliminate accumulated errors that result from interframe coding techniques. I-frames must also be sent for major scene changes. For highly efficient coding, the object is to