Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Koninklijke Philips Corporation N.V.

Coding Technologies Ab

Dolby International Ab

Koninklijke Philips Electronics N.v.

Andreas Hölzer

Stefan Geyersberger

Jürgen Herre

Lars Villemoes

Heiko Purnhagen

Juergen Herre

Christian Helmrich

Johannes Hilpert

Jonas Engdegard

Achim Kuntz

Ralph Sperschneider

Jan Plogsties

Leon Terentiv

Kristofer Kjörling

Christian Ertel

Sascha Dick

Julien Robilliard

Michael Kratschmer

Fabian Küch

Adrian Murtaza

Falko Ridderbusch

Christian Borss

Karsten Linzmeier

Simone Neukam

Thorsten Kastner

Cornelia Falch

Claus Spenger

Jeroen Dirk Breebaart

Alexander Adami

Andreas Silzle

Erik Schuijers

Hanne Stenzel

Werner Oomen

Jonas Röden

Simone FÜG

Jeroen Breebaart

In processing a multi-channel audio signal having at least three original channels, a first downmix channel and a second downmix channel are provided, which are derived from the original channels. For a selected original channel, channel side information are calculated such that a downmix channel or a combined downmix channel including the first and the second downmix channels, when weighted using the channel side information, results in an approximation of the selected original channel. The channel side information and the first and second downmix channels form output data to be transmitted to a decoder, which, in case of a low level decoder only decodes the first and second downmix channels or, in case of a high level decoder provides a full multi-channel audio signal based on the downmix channels and the channel side information.

Compatible multi-channel coding/decoding

In processing a multi-channel audio signal having at least three original channels, a first downmix channel and a second downmix channel are provided, which are derived from the original channels. For a selected original channel of the original channels, channel side information are calculated such that a downmix channel or a combined downmix channel including the first and the second downmix channels, when weighted using the channel side information, results in an approximation of the selected original channel. The channel side information and the first and second downmix channels form output data to be transmitted to a decoder, which, in case of a low level decoder only decodes the first and second downmix channels or, in case of a high level decoder provides a full multi-channel audio signal based on the downmix channels and the channel side information. Since the channel side information only occupy a low number of bits, and since the decoder does not use dematrixing, an efficient and high quality multi-channel extension for stereo players and enhanced multi-channel players is obtained.

A parametric representation of a multi-channel audio signal describes the spatial properties of the audio signal well with compact side information when a coherence information, describing the coherence between a first and a second channel, is derived within a hierarchical encoding process only for channel pairs including a first channel having only information of a left side with respect to a listening position and including a second channel having only information from a right side with respect to a listening position. As within the hierarchical process the multiple audio channels of the audio signal are downmixed iteratively into monophonic channels, one can pick the relevant parameters from an encoding step involving only channel pairs carrying the information needed to describe the spatial properties of the multi-channel audio signal.

Multi-channel hierarchical audio coding with compact side information

In processing a multi-channel audio signal having at least three original channels, a first downmix channel and a second downmix channel are provided, which are derived from the original channels. For a selected original channel of the original channels, channel side information are calculated such that a downmix channel or a combined downmix channel including the first and the second downmix channels, when weighted using the channel side information, results in an approximation of the selected original channel. The channel side information and the first and second downmix channels form output data to be transmitted to a decoder, which, in case of a low level decoder only decodes the first and second downmix channels or, in case of a high level decoder provides a full multi-channel audio signal based on the downmix channels and the channel side information.

Compatible multi-channel coding/decoding by weighting the downmix channel

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Erlangen, Germany

Andreas Hölzer