Moving Picture Experts Group |
The Moving Picture Experts Group or MPEG is a working group of International Organization for Standardization/International Electrotechnical Commission charged with the development of video and audio encoding standards. Since its first meeting in 1988 in Hanover, MPEG has grown to include approximately 350 members from various industries and universities. MPEG s official designation is ISO/IEC JTC1/SC29 WG11.
MPEG (pronounced EM-peg) has standardized the following compression formats and ancillary standards:
=How MPEG works=
The MPEG Codecs use lossy data compression using transform codecs. In lossy transform codecs, samples of picture or sound are taken, chopped into small segments, transformed into a frequency space, and Quantization (signal_processing). The resulting quantized values are then entropy coded.
The moving picture coding systems such as MPEG-1, MPEG-2, and MPEG-4 add an extra step, where the picture content is predicted from past reconstructed images before coding, and only the differences from the reconstructed pictures, and any extra information needed to perform the prediction, are coded.
MPEG standardizes only the bitstream format and how a decoder should interpret that bitstream. The encoders and decoders, themselves, are not standardized in any way but there are reference implementations available for members that produce valid bitstreams for testing. That means that any MPEG-4 decoder can decode any MPEG-4 material (of the same type) regardless of the encoder which produced that material.
=See also=
*Audio codec *Video codec *Video quality *Video compression *Pro-MPEG
=External links=
*[http://www.chiariglione.org/mpeg/ Official MPEG web site] *[http://www.mpeg.org MPEG-related pointers & resources] *[http://erg.abdn.ac.uk/research/future-net/digital-video/mpeg2.html MPEG2 Overview] *[http://www.compression-links.info/MPEG Open list of MPEG papers, libraries, sources]|
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