Dolby International Ab

Coding Technologies Ab

Koninklijke Philips Corporation N.V.

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

Jonas Roeden

Heiko Purnhagen

Lars Villemoes

Kristofer Kjoerling

Juergen Herre

Jonas Engdegard

Andreas Hoelzer

Jeroen Dirk Breebaart

Gerard Herman Hotho

Erik Schuijers

Fredrik Henn

Jeroen Koninklijke Philips Elec NV Breebaart

Erik Koninklijke Philips Elec NV Schuijers

Werner Koninklijke Philips Elec NV Oomen

A method and apparatus for reconstructing N audio channels from M audio channels is disclosed. The method includes receiving a bitstream containing an encoded audio signal representing the M audio channels and decoding the encoded audio signal to obtain a frequency domain representation of the M audio channels. The method further includes extracting a parameter from the bitstream and reconstructing at least one of the N audio channels using the parameter. The parameter represents an angle between two signals, at least one of which is included in the M audio channels.

Audio decoder for audio channel reconstruction

A method performed by an audio decoder for reconstructing N audio channels from an audio signal containing M audio channels is disclosed. The method includes receiving a bitstream containing an encoded audio signal having M audio channels and a set of spatial parameters, the set of spatial parameters including an inter-channel intensity difference parameter and an inter-channel coherence parameter. The encoded audio bitstream is then decoded to obtain a decoded frequency domain representation of the M audio channels, and at least a portion of the frequency domain representation is decorrelated with an all-pass filter having a fractional delay. The all-pass filter is attenuated at locations of a transient. A matrixed version of the decorrelated signals are summed with a matrixed version of the decoded frequency domain representation to obtain N audio signals that collectively having N audio channels where M is less than N.

Audio decoder with core decoder and surround decoder

A multi-channel input signal having at least three original channels is represented by a parameter representation of the multi-channel signal. A first balance parameter, a first coherence parameter, or a first inter-channel time difference between a first channel pair and a second balance parameter, or a second coherence parameter, or a second inter-channel time difference parameter between a second channel pair are calculated. This set of parameters is the parameter representation of the original signals. The first channel pair has two channels, which are different from two channels of a second channel pair. Furthermore, each channel of the two channel pairs is one of the original channels, or a weighted combination of the original channels, and the first channel pair and the second channel pair include information on the three original channels. For multi-channel reconstruction purposes, the parameters are used in addition to down-mixing information to generate a selectable number of output channels in a scalable fashion.

Method for representing multi-channel audio signals

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Solna, Sweden

Jonas Roeden