MPEG Multichannel

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[edit] General Description

MPEG Multichannel is the multichannel Extension to the MPEG-2 Audio Specification it is backwards compatible to the MPEG-1 Multichannel Extension. MPEG-2 Multichannel Decoders in some European DVD players are able to decode non-multichannel streams in MPEG-2 and MPEG-1. NOTE:- MPEG Multichannel is older than the new non-backwards compatible MPEG2-AAC or also known as MPEG2.5. This is later developed and MPEG-4 Audio and MPEG-4plus. The new AAC multichannel (MPEG-2 and MPEG-4) is not compatible with MPEG Multichannel. With the introduction of codec technologies by AUDX and MP3 Surround and newer MPEG audio implementation makes MPEG Multichannel obsolete. Originally Philips was responsible for the development but were to slow to develop the format which was dominated by the much popular dolby digital.

Nowadays it is rarely used a way to conserve 5.1 soundtracks when converting from DVD to SVCD using the DVD2SVCD tools. Only those with players that support VCD, CVD and SVCD with MPEG Multichannel would be able to take advantage.

Technically there are software encoders around that can handle 5.1 but NOT 7.1. The MPEG Multichannel supports 7.1 which is created by players and setups which can decode an MPEG Multichannel bitstream from 5.1 and extract data from the matrix to form 7.1 pseudo-distrete channels of a 7.1 wide setup which includes 5 front channels: left, centre left, centre, centre right and right, with two rear or surround channels and a low frequency effects channel. This is notated as 5/2.1, while a typical 5.1 setup is notated as 3/2.1

A typical MPEG-2 Multichannel stream is 384 kbit/s and goes up to 640 kbit/s for DVD. For SVCD, due to limited Bandwidth, the stream would be 384 kbit/s or somewhere in between 192 kbit/s.

Some DVD players are said to have the capability of reproducing cinema effect from an MPEG Multichannel Bitstream because it can output up to 7.1.