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

Dolby International Ab

Koninklijke Philips Corporation N.V.

Dolby Laboratories Licensing Corporation

Agere Systems Inc.

Dolby Sweden Ab

Koninklijke Philips Electronics N.v.

Karsten Linzmeier

Tobias R Wagenblass

Tobias Friedrich

Juergen Herre

Johannes Hilpert

Claus-Christian Spenger

Alexander Mueller

Ralph Sperschneider

Sascha Disch

Heiko Purnhagen

Jürgen Herre

Harald Popp

Holger Hoerich

Oliver Hellmuth

Christof Fersch

Michael Schug

Lars Villemoes

Kristofer Kjoerling

Bernhard Grill

Nikolaus Rettelbach

Michael C Ward

Dirk Jeroen Breebaart

Jeffrey Charles Riedmiller

Christof Faller

Jonas Engdegard

Jan Plogsties

Andreas Hoelzer

Harald Mundt

Kristofer Kjörling

Karl Jonas Roeden

Martin Wolters

Leif Sehlstrom

Alexander Stahlmann

Robin Thesing

Thorsten Kastner

Alexander Groeschel

Eric Allamanche

Christian Neubauer

Jens Popp

Daniel Homm

Frank Siebenhaar

Ralph Kulessa

Werner Oomen

Andreas Hölzer

Reinhold Boehm

Simon Plain

Leif Sehlström

Mark C Leddy

Vinay Mathew

Jurgen Herre

Andreas Holzer

Kristofer Kjorling

Jeroen Breebaart

Mark Leddy

Jenns Popp

Lars Villemos

According to the present invention, multiple parametrically encoded audio signals can be efficiently combined using an audio signal generator, which generates an audio output signal by combining the down-mix channels and the associated parameters of the audio signals directly within the parameter domain, i.e. without reconstructing or decoding the individual input audio signals prior to the generation of the audio output signal. This is achieved by direct mixing of the associated down-mix channels of the individual input signals. It is one key feature of the present invention that the combination of the down-mix channels is achieved by simple, computationally inexpensive arithmetic operations.

Concept for combining multiple parametrically coded audio sources

The present document relates to audio coding systems. In particular, the present document relates to efficient methods and systems for parametric multi-channel audio coding. An audio encoding system configured to generate a bitstream indicative of a downmix signal and spatial metadata for generating a multi-channel upmix signal from the downmix signal is described. The system comprises a downmix processing unit configured to generate the downmix signal from a multi-channel input signal; wherein the downmix signal comprises m channels and wherein the multi-channel input signal comprises n channels; n, m being integers with m<n. Furthermore, the system comprises a parameter processing unit configured to determine the spatial metadata from the multi-channel input signal. In addition, the system comprises a configuration unit configured to determine one or more control settings for the parameter processing unit based on one or more external settings; wherein the one or more external settings comprise a target data-rate for the bitstream and wherein the one or more control settings comprise a maximum data-rate for the spatial metadata.

Methods for parametric multi-channel encoding

The present document relates to audio coding systems. In particular, the present document relates to efficient methods and systems for parametric multi-channel audio coding. An audio encoding system configured to generate a bitstream indicative of a downmix signal and spatial metadata for generating a multi-channel upmix signal from the downmix signal is described. The system comprises a downmix processing unit configured to generate the downmix signal from a multi-channel input signal; wherein the downmix signal comprises m channels and wherein the multi-channel input signal comprises n channels; n, m being integers with m&#x3c;n. Furthermore, the system comprises a parameter processing unit configured to determine the spatial metadata from the multi-channel input signal. In addition, the system comprises a configuration unit configured to determine one or more control settings for the parameter processing unit based on one or more external settings; wherein the one or more external settings comprise a target data-rate for the bitstream and wherein the one or more control settings comprise a maximum data-rate for the spatial metadata.

A technique including receiving and decoding a coded bitstream encoded with audio content including first audio objects corresponding to a first media content type of two consecutive media content types and second audio objects corresponding to a second media content type of the two consecutive media content types, and audio metadata corresponding to the audio content. The audio metadata including first and second audio object gains, for the first and second audio objects, generated in part based on a first fading curve of the first media content type and a second fading curve of the second media content type, respectively. The technique further includes applying the first and second audio object gains to the first and second audio objects, and rendering a sound field represented by the first audio object with the applied first audio object gain and the second audio object with the applied second audio object gain.

Using metadata to aggregate signal processing operations

The present document describes a method for allocating bits to a frame of a sequence of frames to yield a bitstream having a constant average bitrate, wherein the frame comprises audio data and metadata. The method comprises maintaining an overall bit reservoir and maintaining a virtual bit reservoir being a subset of the overall bit reservoir, such that bits for the metadata of the frame are allocated from the virtual bit reservoir and such that bits for the audio data of the frame are allocated from the overall bit reservoir.

Method and system for bit reservoir control in case of varying metadata

The present document describes a method () for allocating bits to a frame () of a sequence of frames () to yield a bitstream having a constant average bitrate, wherein the frame () comprises audio data and metadata. The method () comprises maintaining () an overall bit reservoir () and maintaining () a virtual bit reservoir () being a subset of the overall bit reservoir (), such that bits for the metadata of the frame () are allocated from the virtual bit reservoir () and such that bits for the audio data of the frame () are allocated from the overall bit reservoir ().

The present document relates to the design of anti-aliasing and/or anti-imaging filters for resamplers using rational resampling factors. In particular, the present document relates to a method for implementing such anti-aliasing and/or anti-imaging filters with reduced computational complexity. In addition, the present document relates to further aspects of an audio encoding and decoding system, such as the phase relation between the channels of a multi-channel audio signal and/or the structure of the bitstream of an encoded audio signal.

System aspects of an audio codec

The present document relates to audio coding systems. In particular, the present document relates to efficient methods and systems for parametric multi-channel audio coding. An audio encoding system () configured to generate a bitstream () indicative of a downmix signal and spatial metadata for generating a multi-channel upmix signal from the downmix signal is described. The system () comprises a downmix processing unit () configured to generate the downmix signal from a multi-channel input signal (); wherein the downmix signal comprises m channels and wherein the multi-channel input signal () comprises n channels; n, m being integers with m&#x3c;n. Furthermore, the system () comprises a parameter processing unit () configured to determine the spatial metadata from the multi-channel input signal (). In addition, the system () comprises a configuration unit () configured to determine one or more control settings for the parameter processing unit () based on one or more external settings; wherein the one or more external settings comprise a target data-rate for the bitstream () and wherein the one or more control settings comprise a maximum data-rate for the spatial metadata.

A decoding system reconstructs an audio signal based on an input signal representing the audio signal by parametric coding or by n discretely coded channels. Parametric decoding proceeds on the basis of a core signal and mixing parameters controlling a spatial synthesis stage, which is supplied with a downmix signal. A controller is responsible for controlling the components of the decoding system, whether in steady-state parametric mode, steady-state discrete decoding mode and transitions between these. In defective frames of the input signal, which do not allow the mixing parameters to be decoded, the controller is configured to perform various error handling procedures including: parametric decoding using previous values of the mixing parameters; continuing parametric decoding for a limited duration, and/or outputting the core signal without spatial synthesis.

Error concealment strategy in a decoding system

The present invention is based on the finding that parameters including: a first set of parameters of a representation of a first portion of an original signal and a second set of parameters of a representation of a second portion of the original signal can be efficiently encoded when the parameters are arranged in a first sequence of tuples and a second sequence of tuples. The first sequence of tuples includes tuples of parameters having two parameters from a single portion of the original signal and the second sequence of tuples includes tuples of parameters having one parameter from the first portion and one parameter from the second portion of the original signal. A bit estimator estimates the number of necessary bits to encode the first and the second sequence of tuples. Only the sequence of tuples, which results in the lower number of bits, is encoded.

Adaptive grouping of parameters for enhanced coding efficiency

A parameter transformer generates level parameters, indicating an energy relation between a first and a second audio channel of a multi-channel audio signal associated to a multi-channel loudspeaker configuration. The level parameter are generated based on object parameters for a plurality of audio objects associated to a down-mix channel, which is generated using object audio signals associated to the audio objects. The object parameters have an energy parameter indicating an energy of the object audio signal. To derive the coherence and the level parameters, a parameter generator is used, which combines the energy parameter and object rendering parameters, which depend on a desired rendering configuration.

Apparatus and method for multi-channel parameter transformation

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Erlangen, Germany

Karsten Linzmeier