The Moving Picture Expert Group (MPEG) is a working group in a subcommittee of ISO/IEC (International Organization for Standardization / International Electrotechnical Commission) in charge of developing international standards for the compression of moving pictures (video), associated audio and their combination. Along with the video and audio coding, MPEG also defines means to multiplex several video, audio and information streams synchronously in one single bitstream.
The basic principle of MPEG video coding is that periodically a complete picture is send and the pictures in between are predicted. Since the decoder can make the same prediction as the coder has made, only the errors on this prediction have to be send.
There are a number of different versions of MPEG:
1Popular video-formats such as DivX and Xvid are based on MPEG-4.