|
|||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
MPEG |
Moving Pictures Experts Group (acronym:MPEG) was formed by the ISO to set standards for audio and video compression and transmission.1 Its first meeting was in May 1988 in Ottawa, Canada. As of late 2005, MPEG has grown to include approximately 350 members per meeting from various industries, universities, and research institutions. MPEG's official designation is ISO/IEC JTC1/SC29 WG11.
Contents |
The MPEG compression methodology is considered as asymmetric--where the encoder is more complex than the decoder.2 The encoder needs to be algorithmic or adaptive whereas the decoder is 'dumb' and carries out fixed actions.2 This is considered advantageous in applications such as broadcasting where the number of expensive complex encoders are small but the number of simple inexpensive decoders is large. This approach of the ISO to standardization in MPEG is considered novel because it is not the encoder which is standardized, instead the way in which a decoder shall interpret the bitstream is defined. A decoder which can successfully interpret the bitstream is said to be compliant.2 The advantage of standardizing the decoder is that over time encoding algorithms can improve yet compliant decoders will continue to function with them.2 The MPEG standards give very little information regarding structure and operation of the encoder and implementers can supply encoders using propriety algorithms.3 This gives scope for competiton between different encoder designs which means that better designs can evolve and users will have greater choice because of different levels of cost and complexity can exist in a range of coders yet a compliant decoder will operate with them all.3
MPEG also standardizes the protocol and syntax under which it is possible to combine or multiplex audio data with video data to produce a digital equivalent of a television program. Many such programs can be multiplexed and MPEG defines the way in which such multiplexes can be created and transported. The definitions include the metadata used by decoders to demultiplex correctly.4
MPEG has standardized the following compression formats and ancillary standards:
In addition, the following standards, while not sequential advances to the video encoding standard as with MPEG-1 through MPEG-4, are referred to by similar notation:
Moreover, relatively more recently than other standards above, MPEG has started following international standards; each of the standards holds multiple MPEG technologies for a way of application. For example, MPEG-A includes a number of technologies on multimedia application format.8
A list of MPEG reference books can be found in 9
|
|||||
|
|||||||||||||||||||||||||||||||||||||||||||
 |
 |
 |
 |
 |
 |
 |
 |