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

Fraunhofer-gesellschaft Zur F&#xd6;rderung Der Angewandten Forschung E.v.

Fraunhofer-gesellschaft Zur F&#xf6;rderung Der Angewandten Forschung E. V.

Srikanth Korse

Markus Multrus

Guillaume Fuchs

Eleni Fotopoulou

Franz Reutelhuber

Stefan Döhla

Fabian Küch

Alexandre Bouthéon

Pallavi Maben

Andrea Eichenseer

Juergen Herre

Jan Büthe

Jan Buethe

Stefan Bayer

Emmanuel Ravelli

Wolfgang Jaegers

Martin Dietz

Oliver Thiergart

Markus Schnell

Stefan Doehla

Goran Markovic

Manfred Lutzky

Fabian Kuech

Sascha Dick

Conrad Benndorf

Jürgen Herre

Sascha Disch

Wolfgang Jagers

Alexandre Boutheon

An apparatus generating a sound field description includes an input signal analyzer acquiring diffuseness data from the input signal; a sound component generator for generating, from the input signal, one or more sound field components of a first group of sound field components comprising for each sound field component a direct component and a diffuse component, and for generating, from the input signal, a second group of sound field components comprising only a direct component. The sound component generator is configured to perform an energy compensation when generating the first group of sound field components, the energy compensation depending on the diffuseness data and at least one of a number of sound field components in the second group, a number of diffuse components in the first group, a maximum order of sound field components of the first group and a maximum order of sound field components of the second group.

Apparatus, method and computer program for encoding, decoding, scene processing and other procedures related to DirAC based spatial audio coding using diffuse compensation

An apparatus for generating a sound field description using an input signal having a mono-signal or a multi-channel signal includes: an input signal analyzer for analyzing the input signal to derive direction data and diffuseness data; a low-order components generator for generating a low-order sound field description from the input signal up to a predetermined order and mode; a mid-order components generator for generating a mid-order sound field description above the predetermined order or at the predetermined order and above the predetermined mode and below or at a first truncation order using a synthesis of at least one direct portion and of at least one diffuse portion using the direction data and the diffuseness data; and a high-order components generator for generating a high-order sound field description having a component above the first truncation order using a synthesis of at least one direct portion.

Apparatus, method and computer program for encoding, decoding, scene processing and other procedures related to DirAC based spatial audio coding using low-order, mid-order and high-order components generators

A multisignal encoder for encoding at least three audio signals, including: a signal preprocessor for individually preprocessing each audio signal to obtain at least three preprocessed audio signals, wherein the preprocessing is performed so that a preprocessed audio signal is whitened with respect to the signal before preprocessing; an adaptive joint signal processor for performing a processing of the at least three preprocessed audio signals to obtain at least three jointly processed signals or at least two jointly processed signals and an unprocessed signal; a signal encoder for encoding each signal to obtain one or more encoded signals; and an output interface for transmitting or storing an encoded multisignal audio signal including the one or more encoded signals, side information relating to the preprocessing and side information relating to the processing.

Multisignal audio coding using signal whitening as processing

In multichannel audio coding, improved computational efficiency is achieved by computing comparison parameters for ITD compensation between any two channels in the frequency domain for a parametric audio encoder. This may mitigate negative effects on encoder parameter estimates.

Multichannel audio coding

An apparatus for encoding a multi-channel signal having at least two channels, has: a downmixer for calculating a downmix signal from the multi-channel signal; a parameter calculator for calculating a side gain from a first channel of the at least two channels and a second channel of the at least two channels and for calculating a residual gain from the first channel and the second channel; and an output interface for generating an output signal, the output signal having information on the downmix signal, and on the side gain and the residual gain.

Apparatus and method for encoding or decoding a multichannel signal using a side gain and a residual gain

An apparatus for estimating an inter-channel time difference between a first channel signal and a second channel signal, includes a signal analyzer for estimating a signal characteristic of the first channel signal or the second channel signal or both signals or a signal derived from the first channel signal or the second channel signal; a calculator for calculating a cross-correlation spectrum for a time block from the first channel signal in the time block and the second channel signal in the time block; a weighter for weighting a smoothed or non-smoothed cross-correlation spectrum to obtain a weighted cross correlation spectrum using a first weighting procedure or using a second weighting procedure depending on a signal characteristic estimated by the signal analyzer, wherein the first weighting procedure is different from the second weighting procedure; and a processor for processing the weighted cross-correlation spectrum to obtain the inter-channel time difference.

Apparatus, method or computer program for estimating an inter-channel time difference

An apparatus for downmixing a multi-channel signal having at least two channels, has: a downmixer for calculating a downmix signal from the multi-channel signal, wherein the downmixer is configured to calculate the downmix using an absolute phase compensation, so that a channel having a lower energy among the at least two channels is only rotated or is rotated stronger than a channel having a greater energy in calculating the downmix signal; and an output interface for generating an output signal, the output signal having information on the downmix signal.

Apparatus and method for downmixing or upmixing a multichannel signal using phase compensation

An apparatus for generating a sound field description using an input signal having a mono-signal or a multi-channel signal comprises: an input signal analyzer for analyzing the input signal to derive direction data and diffuseness data; a low-order components generator for generating a low-order sound field description from the input signal up to a predetermined order and mode; a mid-order components generator for generating a mid-order sound field description above the predetermined order or at the predetermined order and above the predetermined mode and below or at a first truncation order using a synthesis of at least one direct portion and of at least one diffuse portion using the direction data and the diffuseness data; and a high-order components generator for generating a high-order sound field description having a component above the first truncation order using a synthesis of at least one direct portion.

An apparatus for generating a sound field description from an input signal having at least two channels has: an input signal analyzer for obtaining direction data and diffuseness data from the input signal; an estimator for estimating a first energy- or amplitude-related measure for an omnidirectional component derived from the input signal and for estimating a second energy- or amplitude-related measure for a directional component derived from the input signal, and a sound component generator for generating sound field components of the sound field, wherein the sound component generator is configured to perform an energy compensation of the directional component using the first energy- or amplitude-related measure, the second energy- or amplitude-related measure, the direction data and the diffuseness data.

Apparatus, method and computer program for encoding, decoding, scene processing and other procedures related to DirAC based spatial audio coding using direct component compensation

An apparatus for generating a sound field description from an input signal having one or more channels including: an input signal analyzer for obtaining diffuseness data from the input signal; a sound component generator for generating, from the input signal, one or more sound field components of a first group of sound field components having for each sound field component a direct component and a diffuse component, and for generating, from the input signal, a second group of sound field components having only a direct component, the sound component generator being configured to perform an energy compensation when generating the first group of sound field components, the energy compensation depending on the diffuseness data and a number of sound field components in the second group, a number of diffuse components in the first group, or a maximum order of sound field components.

An apparatus for encoding an audio signal includes: a converter for converting the audio signal into a spectral representation; a scale parameter calculator for calculating a first set of scale parameters from the spectral representation: a downsampler for downsampling the first set of scale parameters to obtain a second set of scale parameters, a second number of scale parameters in the second set of scale parameters being lower than a first number of scale parameters in the first set of scale parameters; a scale parameter encoder for generating an encoded representation of the second set of scale parameters; a spectral processor for processing the spectral representation using a third set of scale parameters, the third set of scale parameters having a third number of scale parameters being greater than the second number of scale parameters, the spectral processor being configured to use the first set of scale parameters or to derive the third set of scale parameters from the second set of scale parameters or from the encoded representation of the second set of scale parameters using an interpolation operation; and an output interface for generating an encoded output signal comprising information on the encoded representation of the spectral representation and information on the encoded representation of the second set of scale parameters.

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Erlangen, Germany

Srikanth Korse