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

Voiceage Corporation

Fraunhofer-Gesellschaft Zur Förderung Der Angewandten Forschung E. V.

Fraunhofer-Gesellschaft Zur Förderung Der Angewandten Forschung E.v.

Other

Guillaume Fuchs

Markus Multrus

Stefan Bayer

Bernhard Grill

Nikolaus Rettelbach

Sascha Disch

Emmanuel Ravelli

Ralf Geiger

Stefan Geyersberger

Juergen Herre

Markus Schnell

Max Neuendorf

Martin Dietz

Frederik Nagel

Harald Popp

Gerald Schuller

Benjamin Schubert

Wolfgang Jaegers

Stefan Doehla

Eleni Fotopoulou

Fabian Küch

Christian Helmrich

Matthias Neusinger

Johannes Hilpert

Jeremie Lecomte

Philippe Gournay

Ulrich Kraemer

Bernd Edler

Redwan Salami

Bruno Bessette

Goran Markovic

Jürgen Herre

Oliver Thiergart

Stefan Wabnik

Jérémie Lecomte

Konstantin Schmidt

Florin Ghido

Marc Gayer

Andreas Niedermeier

Tom Baeckstroem

Christian Neukam

Conrad Benndorf

Manuel Jander

Adrian Tomasek

Manfred Lutzky

Oliver Wuebbolt

Fabian Kuech

Christian Griebel

Stefan Döhla

Jens Hirschfeld

Roch Lefebvre

Jimmy Lapierre

Vignesh Subbaraman

Patrick Warmbold

Alexandre Bouthéon

Oliver Weiss

Grzegorz Pietrzyk

Srikanth Korse

Virgilio Bacigalupo

Franz Reutelhuber

Julien Robilliard

Jan Buethe

Oliver Wübbolt

Andrea Eichenseer

Jan Büthe

Yoshikazu Yokotani

Christian Borss

Anthony Lombard

Pallavi Maben

Stephan Wilde

Andreas Walther

Matthias Hildenbrand

Arne Borsum

Vesa Ruoppila

Arthur Tritthart

Tom Bäckström

Bernard Grill

Stefam Geyersberger

Raif Geiger

Tilo Wik

Christian Greibel

Jan Frederik Kiene

Wolfgang Jagers

Sneha Das

Archit Tamarapu

Nicola Pia

Kishan Gupta

Christian BORß

Jurgen Herre

An audio encoder for providing an output signal using an input audio signal includes a patch generator, a comparator and an output interface. The patch generator generates at least one bandwidth extension high-frequency signal, wherein a bandwidth extension high-frequency signal includes a high-frequency band. The high-frequency band of the bandwidth extension high-frequency signal is based on a low frequency band of the input audio signal. A comparator calculates a plurality of comparison parameters. A comparison parameter is calculated based on a comparison of the input audio signal and a generated bandwidth extension high-frequency signal. Each comparison parameter of the plurality of comparison parameters is calculated based on a different offset frequency between the input audio signal and a generated bandwidth extension high-frequency signal. Further, the comparator determines a comparison parameter from the plurality of comparison parameters, wherein the determined comparison parameter fulfils a predefined criterion.

Audio encoder and bandwidth extension decoder

An audio decoder for providing a decoded audio representation on the basis of an encoded audio representation includes a filter for providing an enhanced audio representation of the decoded audio representation. The filter is configured to obtain a plurality of scaling values, which are associated with different frequency bins or frequency ranges, on the basis of spectral values of the decoded audio representation which are associated with different frequency bins or frequency ranges, and the filter is configured to scale spectral values of the decoded audio signal representation, or a pre-processed version thereof, using the scaling values, to obtain the enhanced audio representation. An apparatus for determining a set of values defining characteristics of a filter for providing an enhanced audio representation on the basis of a decoded audio representation is also described.

Audio decoder, apparatus for determining a set of values defining characteristics of a filter, methods for providing a decoded audio representation, methods for determining a set of values defining characteristics of a filter and computer program

Apparatus for processing an audio scene representing a sound field, the audio scene having information on a transport signal and a first set of parameters. The apparatus has a parameter processor for processing the first set of parameters to obtain a second set of parameters, wherein the parameter processor is configured to calculate at least one raw parameter for each output time frame using at least one parameter of the first set of parameters for the input time frame, to calculate a smoothing information such as a factor for each raw parameter in accordance with a smoothing rule, and to apply a corresponding smoothing information to the corresponding raw parameter to derive the parameter of the second set of parameters for the output time frame. The apparatus further has an output interface for generating a processed audio scene using the second set of parameters and the information on the transport signal.

Apparatus, method, or computer program for processing an encoded audio scene using a parameter smoothing

An apparatus for generating a synthesis audio signal using a patching control signal has a first converter, a spectral domain patch generator, a high frequency reconstruction manipulator and a combiner. The first converter is configured for converting a time portion of an audio signal into a spectral representation. The spectral domain patch generator is configured for performing a plurality of different spectral domain patching algorithms, wherein each patching algorithm generates a modified spectral representation having spectral components in an upper frequency band derived from corresponding spectral components in a core frequency band of the audio signal. The spectral domain patch generator is furthermore configured to select a first spectral domain patching algorithm from the plurality of patching algorithms for a first time portion and a second spectral domain patching algorithm from the plurality of patching algorithm for a second different time portion in accordance with the patching control signal to obtain the modified spectral representation.

Apparatus and method for generating a synthesis audio signal and for encoding an audio signal

Apparatus for processing an audio scene representing a sound field, the audio scene comprising information on a transport signal and a set of parameters. The apparatus comprising an output interface for generating a processed audio scene using the set of parameters and the information on the transport signal, wherein the output interface is configured to generate a raw representation of two or more channels using the set of parameters and the transport signal and a multichannel enhancer for generating an enhancement representation of the two or more channels using the transport signal, and a signal combiner for combining the raw representation of the two or more channels and the enhancement representation of the two or more channels to obtain the processed audio scene.

Apparatus, method, or computer program for processing an encoded audio scene using a bandwidth extension

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 audio encoder has a first information sink oriented encoding branch such as a spectral domain encoding branch, a second information source or SNR oriented encoding branch such as an LPC-domain encoding branch, and a switch for switching between the first and second encoding branches, the second encoding branch having a converter into a specific domain different from the spectral domain such as an LPC analysis stage generating an excitation signal, and the second encoding branch having a specific domain coding branch such as LPC domain processing branch, and a specific spectral domain coding branch such as LPC spectral domain processing branch, and an additional switch for switching between the specific domain coding branch and the specific spectral domain coding branch. An audio decoder has a first domain decoder, a second domain decoder, and a third domain decoder as well as two cascaded switches for switching between the decoders.

Low bitrate audio encoding/decoding scheme having cascaded switches

An apparatus for decoding an encoded multichannel signal includes: a base channel decoder for decoding an encoded base channel to acquire a decoded base channel; a decorrelation filter for filtering at least a portion of the decoded base channel to acquire a filling signal; and a multichannel processor for performing a multichannel processing using a spectral representation of the decoded base channel and a spectral representation of the filling signal, wherein the decorrelation filter is a broad band filter and the multichannel processor is configured to apply a narrow band processing to the spectral representation of the decoded base channel and the spectral representation of the filling signal.

Apparatus for encoding or decoding an encoded multichannel signal using a filling signal generated by a broad band filter

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

An audio decoder for providing a decoded audio information on the basis of an encoded audio information includes a linear-prediction-domain decoder configured to provide a first decoded audio information on the basis of an audio frame encoded in a linear prediction domain, a frequency domain decoder configured to provide a second decoded audio information on the basis of an audio frame encoded in a frequency domain, and a transition processor. The transition processor is configured to obtain a zero-input-response of a linear predictive filtering, wherein an initial state of the linear predictive filtering is defined depending on the first decoded audio information and the second decoded audio information, and modify the second decoded audio information depending on the zero-input-response, to obtain a smooth transition between the first and the modified second decoded audio information.

Audio decoder, method and computer program using a zero-input-response to obtain a smooth transition

An encoder for providing an audio stream on the basis of a transform-domain representation of an input audio signal includes a quantization error calculator configured to determine a multi-band quantization error over a plurality of frequency bands of the input audio signal for which separate band gain information is available. The encoder also includes an audio stream provider for providing the audio stream such that the audio stream includes information describing an audio content of the frequency bands and information describing the multi-band quantization error. A decoder for providing a decoded representation of an audio signal on the basis of an encoded audio stream representing spectral components of frequency bands of the audio signal includes a noise filler for introducing noise into spectral components of a plurality of frequency bands to which separate frequency band gain information is associated on the basis of a common multi-band noise intensity value.

Audio encoder, audio decoder, methods for encoding and decoding an audio signal, audio stream and a computer program

An encoder provides an audio stream based on a transform-domain representation of an input audio signal and includes a quantization error calculator configured to determine a multi-band quantization error over a plurality of frequency bands of the input audio signal for which separate band gain information is available. The encoder also includes an audio stream provider for providing the audio stream such that the audio stream includes information describing an audio content of the frequency bands and information describing the multi-band quantization error. A decoder provides a decoded representation of an audio signal based on an encoded audio stream representing spectral components of frequency bands of the audio signal and includes a noise filler for introducing noise into spectral components of a plurality of frequency bands to which separate frequency band gain information is associated on the basis of a common multi-band noise intensity value.

There are disclosed several examples of encoding and decoding technique. In particular, an audio synthesizer for generating a synthesis signal from a downmix signal, includes:

Parameter encoding and decoding

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Erlangen, Germany

Guillaume Fuchs