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

Dolby International Ab

Robert Boschgmbh

Friedrich-alexander-universitat Erlangen-nürnberg

Bernd Edler

Sascha Disch

Ralf Geiger

Christian Helmrich

Stefan Bayer

Gerald Schuller

Markus Multrus

Markus Schnell

Frederik Nagel

Christian Neukam

Guillaume Fuchs

Bernhard Grill

Konstantin Schmidt

Max Neuendorf

Manfred Lutzky

Marc Gayer

Markus Lohwasser

Johannes Hilpert

Nikolaus Rettelbach

Goran Markovic

Matthias Neusinger

Jérémie Lecomte

Julien Robilliard

Harald Popp

Lars Villemoes

Juergen Herre

Stefan Geyersberger

Ralph Sperschneider

Benjamin Schubert

Florin Ghido

Wolfgang Jaegers

Oliver Hellmuth

Heiko Purnhagen

Martin Dietz

Jürgen Herre

Markus Schmidt

Balaji Nagendran Thoshkahna

Michael Mellar

Stefan Reuschl

Jan Buethe

Christian Borss

Franz Reutelhuber

Nils Werner

Janine Sukowski

Jurgen Herre

Jouni Paulus

Tom Baeckstroem

Thorsten Kastner

Hendrik Fuchs

Julien Robillard

Pontus Carlsson

Eleni Fotopoulou

Andreas Niedermeier

Christian Uhle

Christian Ertel

Karlheinz Brandenburg

Ulrich Kraemer

Albert Heuberger

Florian Schuh

Jan Büthe

Frank Klefenz

Pallavi Maben

Tobias Schwegler

Andreas Buechner

Jan Frederik Kiene

Elena Burdiel Pérez

Steven Van De Par

Ning Guo

Waldo Nogueira

Manfred Lutzki

Andreas Büchner

Sasch Disch

Tom BÄCKSTRÖM

Steven Van Der Par

Elena Burdiel Perez

Christian BORß

Martin Strauss

An encoder for encoding a current frame of an audio signal depending on one or more previous frames of the audio signal is provided. The previous frames precede the current frame, each of the current frame and the one or more previous frames having one or more harmonic components of the audio signal, each of the current frame and the one or more previous frames having a plurality of spectral coefficients in a frequency domain or in a transform domain. To generate an encoding of the current frame, the encoder is to determine an estimation of two harmonic parameters for each of the harmonic components of a most previous frame of the previous frames. Moreover, the encoder is to determine the estimation of the two harmonic parameters for each of the harmonic components of the most previous frame using a first group of three or more of the plurality of spectral coefficients of each of the previous frames of the audio signal.

Encoder, decoder, encoding method and decoding method for frequency domain long-term prediction of tonal signals for audio coding

An apparatus processing an encoded signal to acquire first and second frames comprising spectral values and an aliasing portion; applying a transform to the first frame using a first window function to acquire a first block of samples, applying another transform to a first portion of the second frame using a second window function, and applying another one or more transforms to a second portion of the second frame using one or more third window functions to acquire a second block of samples; and post-processing the second block of samples using a folding-out operation to acquire a post-processed second block of samples comprising a portion of the second block of samples overlapping with the first block of samples in a multi-overlap region, windowing the post-processed second block of samples using an auxiliary window function, and overlap-adding a windowed post-processed second block of samples and the first block of samples.

Apparatus and method for decoding an encoded audio or image signal using an auxiliary window function

Embodiments provide a method for processing an audio signal, including: performing a cascaded lapped critically sampled transform on two partially overlapping blocks of samples of the audio signal, to obtain sets of subband samples; identifying one or more sets of subband samples that in combination represent the same region of the time-frequency plane; performing time-frequency transforms on the identified one or more sets of subband samples, to obtain one or more time-frequency transformed subband samples, each of which represents the same region in the time-frequency plane; performing a weighted combination of two corresponding sets of subband samples or time-frequency transformed versions thereof, to obtain aliasing reduced subband representations of the audio signal.

Time-varying time-frequency tilings using non-uniform orthogonal filterbanks based on MDCT analysis/synthesis and TDAR

A schematic block diagram of a decoder for decoding an encoded audio signal is shown. The decoder includes an adaptive spectrum-time converter and an overlap-add-processor. The adaptive spectrum-time converter converts successive blocks of spectral values into successive blocks of time values, e.g. via a frequency-to-time transform. Furthermore, the adaptive spectrum-time converter receives a control information and switches, in response to the control information, between transform kernels of a first group of transform kernels including one or more transform kernels having different symmetries at sides of a kernel, and a second group of transform kernels including one or more transform kernels having the same symmetries at sides of a transform kernel. Moreover, the overlap-add-processor overlaps and adds the successive blocks of time values to obtain decoded audio values, which may be a decoded audio signal.

Decoder for decoding an encoded audio signal and encoder for encoding an audio signal

A downmixer for downmixing a multi-channel signal having at least two channels, includes: a weighting value estimator for estimating band-wise weighting values for the at least two channels; a spectral weighter for weighting spectral domain representations of the at least two channels using the band-wise weighting values; a converter for converting weighted spectral domain representations of the at least two channels into time representations of the at least two channels; and a mixer for mixing the time representations of the at least two channels to obtain a downmix signal.

Downmixer and method of downmixing

An apparatus for generating a decoded two-channel signal, comprising: a parametric decoder for providing parametric data for a second set of second spectral portions and a two-channel identification identifying for a second spectral portion of the second set of second spectral portions either a first two-channel representation for the second spectral portion of the second set of second spectral portions or a second two-channel representation for the second spectral portion of the second set of second spectral portions, the second two-channel representation being different from the first two-channel representation; and a frequency regenerator for regenerating the second spectral portion of the second set of second spectral portions depending on a first spectral portion of a first set of first spectral portions, the parametric data for the second spectral portion of the second set of second spectral portions and the two-channel identification for the second spectral portion of the second set of second spectral portions to acquire a regenerated second spectral portion of the second set of second spectral portions.

Audio encoder, audio decoder and related methods using two-channel processing within an intelligent gap filling framework

An embodiment of an apparatus for generating audio subband values in audio subband channels includes an analysis windower for windowing a frame of time-domain audio input samples being in a time sequence extending from an early sample to a later sample using an analysis window function including a sequence of window coefficients to obtain windowed samples. The analysis window function includes a first number of window coefficients derived from a larger window function including a sequence of a larger second number of window coefficients, wherein the window coefficients of the window function are derived by an interpolation of window coefficients of the larger window function. The apparatus further includes a calculator for calculating the audio subband values using the windowed samples.

Apparatus and method for generating audio subband values and apparatus and method for generating time-domain audio samples

An encoder for encoding an audio signal is configured to encode the audio signal in a transform domain or filter-bank domain, is configured to determine spectral coefficients of the audio signal for a current frame and at least one previous frame, and is configured to selectively apply predictive encoding to a plurality of individual spectral coefficients or groups of spectral coefficients which are separated by at least one spectral coefficient.

Audio encoder, audio decoder, method for encoding an audio signal and method for decoding an encoded audio signal

An audio similarity evaluator obtains envelope signals for a plurality of frequency ranges on the basis of an input audio signal. The audio similarity evaluator is configured to obtain a modulation information associated with the envelope signals for a plurality of modulation frequency ranges, wherein the modulation information describes the modulation of the envelope signals. The audio similarity evaluator is configured to compare the obtained modulation information with a reference modulation information associated with a reference audio signal, in order to obtain an information about a similarity between the input audio signal and the reference audio signal. An audio encoder uses such an audio similarity evaluator. Another audio similarity evaluator uses a neural net trained using the audio similarity evaluator.

Audio similarity evaluator, audio encoder, methods and computer program

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Fuerth, Germany

Bernd Edler