MPEG Multichannel
Encyclopedia
MPEG Multichannel is an extension to the MPEG-1 Layer II audio
compression specification, as defined in the MPEG-2
Audio standard (ISO/IEC
13818-3), which allows it provide up to 5.1-channels (surround sound
) of audio. To maintain backwards compatibility with the older 2-channel (stereo) audio specification, it uses a channel matrixing scheme, where the additional channels are mixed into the two backwards compatible channels. Extra information in the data stream (ignored by older hardware) contains signals to process extra channels from the matrix.
It was originally a mandatory part of the DVD
specification for European DVDs, but was dropped in late 1997, and is rarely used as a result.
The Super Video CD
(SVCD) standard supports MPEG Multichannel. Player support for this audio format is nearly non-existent however, and it is rarely used.
MPEG Multichannel audio was proposed for use in the ATSC
digital TV broadcasting standard, but Dolby Digital
(aka. AC-3, A/52) was chosen instead. This is a matter of significant controversy, as it has been revealed that the organizations (The Massachusetts Institute of Technology
and Zenith Electronics
) behind 2 of the 4 voting board members received tens of millions of dollars of compensation from secret deals with Dolby Laboratories
in exchange for their votes.
MPEG Multichannel–compatible equipment would bear either the MPEG Multichannel or MPEG Empowered logos.
Sound
Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...
compression specification, as defined in the MPEG-2
MPEG-2
MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods which permit storage and transmission of movies using currently available storage media and transmission...
Audio standard (ISO/IEC
International Electrotechnical Commission
The International Electrotechnical Commission is a non-profit, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies – collectively known as "electrotechnology"...
13818-3), which allows it provide up to 5.1-channels (surround sound
Surround sound
Surround sound encompasses a range of techniques such as for enriching the sound reproduction quality of an audio source with audio channels reproduced via additional, discrete speakers. Surround sound is characterized by a listener location or sweet spot where the audio effects work best, and...
) of audio. To maintain backwards compatibility with the older 2-channel (stereo) audio specification, it uses a channel matrixing scheme, where the additional channels are mixed into the two backwards compatible channels. Extra information in the data stream (ignored by older hardware) contains signals to process extra channels from the matrix.
It was originally a mandatory part of the DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....
specification for European DVDs, but was dropped in late 1997, and is rarely used as a result.
The Super Video CD
Super Video CD
Super Video CD is a digital format for storing video on standard compact discs. SVCD was intended as a successor to Video CD and an alternative to DVD-Video, and falls somewhere between both in terms of technical capability and picture quality...
(SVCD) standard supports MPEG Multichannel. Player support for this audio format is nearly non-existent however, and it is rarely used.
MPEG Multichannel audio was proposed for use in the ATSC
ATSC
ATSC standards are a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks....
digital TV broadcasting standard, but Dolby Digital
Dolby Digital
Dolby Digital is the name for audio compression technologies developed by Dolby Laboratories. It was originally called Dolby Stereo Digital until 1994. Except for Dolby TrueHD, the audio compression is lossy. The first use of Dolby Digital was to provide digital sound in cinemas from 35mm film prints...
(aka. AC-3, A/52) was chosen instead. This is a matter of significant controversy, as it has been revealed that the organizations (The Massachusetts Institute of Technology
Massachusetts Institute of Technology
The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...
and Zenith Electronics
Zenith Electronics
Zenith Electronics Corporation is a brand of the South Korean company LG Electronics. The company was previously an American manufacturer of televisions and other consumer electronics, and was headquartered in Lincolnshire, Illinois. LG Electronics acquired a controlling share of Zenith in 1995...
) behind 2 of the 4 voting board members received tens of millions of dollars of compensation from secret deals with Dolby Laboratories
Dolby Laboratories
Dolby Laboratories, Inc. , often shortened to Dolby Labs, is an American company specializing in audio noise reduction and audio encoding/compression.-History:...
in exchange for their votes.
MPEG Multichannel–compatible equipment would bear either the MPEG Multichannel or MPEG Empowered logos.