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

Sascha Dick

Johannes Hilpert

Andreas Hoelzer

Christian Helmrich

Achim Kuntz

Christian Ertel

Nikolaus Rettelbach

Florian Schuh

Richard Fueg

Jan Plogsties

Matthias Neusinger

Julien Robilliard

Simone Fueg

Tobias Schwegler

Andreas Holzer

Frederik Nagel

Juergen Herre

Stefan Bayer

Goran Markovic

Jürgen Herre

Eleni Fotopoulou

Fabian Kuech

Michael Kratschmer

Adrian Murtaza

Christian Borss

Simone Neukam

Alexander Adami

Andreas Silzle

Sascha Disch

Markus Multrus

Oliver Wuebbolt

Fabian Küch

Hanne Stenzel

Srikanth Korse

Pallavi Maben

Oliver Wübbolt

Andreas Hölzer

Richard Füg

Pablo Manuel Delgado

Simone FÜG

Richard FÜG

A frequency-domain audio codec is provided with the ability to additionally support a certain transform length in a backward-compatible manner, by the following: the frequency-domain coefficients of a respective frame are transmitted in an interleaved manner irrespective of the signalization signaling for the frames as to which transform length actually applies, and additionally the frequency-domain coefficient extraction and the scale factor extraction operate independent from the signalization. By this measure, old-fashioned frequency-domain audio coders/decoders, insensitive for the signalization, would be able to nevertheless operate without faults and with reproducing a reasonable quality. Concurrently, frequency-domain audio coders/decoders able to support the additional transform length would offer even better quality despite the backward compatibility. As far as coding efficiency penalties due to the coding of the frequency domain coefficients in a manner transparent for older decoders are concerned, same are of comparatively minor nature due to the interleaving.

Frequency-domain audio coding supporting transform length switching

An apparatus for encoding a multi-channel signal having at least three channels includes an iteration processor, a channel encoder and an output interface. The iteration processor is configured to calculate inter-channel correlation values between each pair of the at least three channels, for selecting a pair including a highest value or including a value above a threshold, and for processing the selected pair using a multi-channel processing operation to derive first multi-channel parameters for the selected pair and to derive first processed channels. The iteration processor is configured to perform the calculating, the selecting and the processing using at least one of the processed channels to derive second multi-channel parameters and second processed channels. The channel encoder is configured to encode channels resulting from an iteration processing to obtain encoded channels. The output interface is configured to generate an encoded multi-channel signal including the encoded channels and the first and second multi-channel parameters.

Apparatus and method for encoding or decoding a multi-channel signal

An apparatus for decoding an encoded multichannel signal of a current frame to obtain three or more current audio output channels is provided. A multichannel processor is adapted to select two decoded channels from three or more decoded channels depending on first multichannel parameters. Moreover, the multichannel processor is adapted to generate a first group of two or more processed channels based on the selected channels. A noise filling module is adapted to identify for at least one of the selected channels, one or more frequency bands, within which all spectral lines are quantized to zero, and to generate a mixing channel using, depending on side information, a proper subset of three or more previous audio output channels that have been decoded, and to fill the spectral lines of frequency bands, within which all spectral lines are quantized to zero, with noise generated using spectral lines of the mixing channel.

Apparatus and method for stereo filling in multichannel coding

An apparatus for generating loudspeaker signals includes an object metadata processor configured to receive metadata, to calculate a second position of the audio object depending on the first position of the audio object and on a size of a screen if the audio object is indicated in the metadata as being screen-related, to feed the first position of the audio object as the position information into the object renderer if the audio object is indicated in the metadata as being not screen-related, and to feed the second position of the audio object as the position information into the object renderer if the audio object is indicated in the metadata as being screen-related. The apparatus further includes an object renderer configured to receive an audio object and to generate the loudspeaker signals depending on the audio object and on position information.

Apparatus and method for screen related audio object remapping

An audio decoder for providing at least four audio channel signals on the basis of an encoded representation is configured to provide a first residual signal and a second residual signal on the basis of a jointly encoded representation of the first residual signal and of the second residual signal using a multi-channel decoding. The audio decoder is configured to provide a first audio channel signal and a second audio channel signal on the basis of a first downmix signal and the first residual signal using a residual-signal-assisted multi-channel decoding. The audio decoder is configured to provide a third audio channel signal and a fourth audio channel signal on the basis of a second downmix signal and the second residual signal using a residual-signal-assisted multi-channel decoding. An audio encoder is based on corresponding considerations.

Audio encoder, audio decoder, methods and computer program using jointly encoded residual signals

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

An audio analyzer configured to obtain spectral domain representations of two or more input audio signals. Additionally the audio analyzer is configured to obtain directional information associated with spectral bands of the spectral domain representations and to obtain loudness information associated with different directions as an analysis result. Contributions to the loudness information are determined in dependence on the directional information.

Directional loudness map based audio processing

Audio encoder for encoding audio input data to obtain audio output data includes an input interface for receiving a plurality of audio channels, a plurality of audio objects and metadata related to one or more of the plurality of audio objects; a mixer for mixing the plurality of objects and the plurality of channels to obtain a plurality of pre-mixed channels, each pre-mixed channel including audio data of a channel and audio data of at least one object; a core encoder for core encoding core encoder input data; and a metadata compressor for compressing the metadata related to the one or more of the plurality of audio objects, wherein the audio encoder is configured to operate in at least one mode of the group of two modes.

Concept for audio encoding and decoding for audio channels and audio objects

An apparatus for converting an object position of an audio object from a Cartesian representation to a spherical representation is described. A basis area of the Cartesian representation is subdivided into a plurality of basis area triangles, and wherein a plurality of spherical-domain triangles are inscribed into a circle of a spherical representation. The apparatus is configured to determine, in which of the basis area triangles a projection of the object position of the audio object into the base area is arranged; and the apparatus is configured to determine a mapped position of the projection of the object position using a linear transform, which maps the base area triangle onto its associated spherical domain triangle. The apparatus is configured to derive an azimuth angle and an intermediate radius value from the mapped position. The apparatus is configured to obtain a spherical domain radius value and an elevation angle in dependence on the intermediate radius value and in dependence on a distance of the object position from the base area. An apparatus for converting an object position of an audio object from a spherical representation to a spherical representation, applications of these apparatuses, methods and computer programs are also described.

Apparatuses for converting an object position of an audio object, audio stream provider, audio content production system, audio playback apparatus, methods and computer programs

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Sascha Dick