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

Patrick Gampp

Christian Uhle

Oliver Hellmuth

Peter Prokein

Sascha Disch

Julia Havenstein

Antonios Karampourniotis

Juergen Herre

Jürgen Herre

Daniel Richter

Emanuel Habets

Andreas Walther

Sebastian Scharrer

Stefan Finauer

Michael Kratz

Felix Fleischmann

Christian Stoecklmeier

Stefan Varga

Jurgen Herre

Christian Stocklmeier

Christian STÖCKLMEIER

An apparatus for processing an audio signal includes a separator for separating a first portion of a spectrum of the audio signal from a second portion of the spectrum of the audio signal, the first portion having a first signal characteristic and the second portion having a second signal characteristic. The apparatus includes a first bandwidth extender for extending a bandwidth of the first portion using first parameters associated with the first signal characteristic, for obtaining a first extended portion and includes a second bandwidth extender for extending a bandwidth of the second portion using second parameters associated with the second signal characteristic, for obtaining a second extended portion. The apparatus includes a combiner configured for using the first extended portion and the second extended portion for obtaining an extended combined audio signal.

Apparatus and methods for processing an audio signal

An apparatus for determining a predetermined characteristic related to an artificial bandwidth limitation processing of an audio signal has a slope evaluator configured for evaluating a slope of a spectrum of the audio signal to obtain a slope evaluation result. The apparatus has a frequency evaluator configured for evaluating a cut-off frequency of the spectrum of the audio signal to obtain a frequency evaluation result, and has a processor for providing an information indicating that the audio signal has the predetermined characteristic dependent on an evaluation of the slope evaluation result and an evaluation of the frequency evaluation result.

Apparatus and method for determining a predetermined characteristic related to an artificial bandwidth limitation processing of an audio signal

What is described is an apparatus for post-processing an audio signal, having: a time-spectrum-converter for converting the audio signal into a spectral representation having a sequence of spectral frames; a prediction analyzer for calculating prediction filter data for a prediction over frequency within a spectral frame; a shaping filter controlled by the prediction filter data for shaping the spectral frame to enhance a transient portion within the spectral frame; and a spectrum-time-converter for converting a sequence of spectral frames having a shaped spectral frame into a time domain.

Apparatus and method for post-processing an audio signal using prediction based shaping

Apparatus for post-processing an audio signal, including: a converter for converting the audio signal into a time-frequency representation; a transient location estimator for estimating a location in time of a transient portion using the audio signal or the time-frequency representation; and a signal manipulator for manipulating the time-frequency representation, wherein the signal manipulator is configured to reduce or eliminate a pre-echo in the time-frequency representation at a location in time before the transient location or to perform a shaping of the time-frequency representation at the transient location to amplify an attack of the transient portion.

Apparatus for post-processing an audio signal using a transient location detection

An apparatus for determining a predetermined characteristic related to a spectral enhancement processing of an audio signal includes a deriver configured for obtaining a spectrum of the audio signal and for deriving a local maximum signal from the spectrum. The apparatus includes a determiner configured for determining a similarity between segments of the local maximum signal and includes a processor for providing an information indicating that the audio signal includes the predetermined characteristic dependent on an evaluation of the similarity.

Apparatus and method for determining a predetermined characteristic related to a spectral enhancement processing of an audio signal

An apparatus for generating one or more audio output channel signals depending on two or more audio input channel signals is provided. Each of the two or more audio input channel signals comprises direct signal portions and ambient signal portions. The apparatus comprises a filter determination unit for determining a filter by estimating first power spectral density information and by estimating second power spectral density information. Moreover, the apparatus comprises a signal processor for generating the one or more audio output channel signals by applying the filter on the two or more audio input channel signals. The first power spectral density information indicates power spectral density information on the two or more audio input channel signals, and the second power spectral density information indicates power spectral density information on the ambient signal portions of the two or more audio input channel signals.

Apparatus and method for multichannel direct-ambient decompostion for audio signal processing

An apparatus for enhancing an audio signal includes a signal processor for processing the audio signal in order to reduce or eliminate transient and tonal portions of the processed signal and a decorrelator for generating a first decorrelated signal and a second decorrelated signal from the processed signal. The apparatus further includes a combiner for weightedly combining the first and the second decorrelated signal and the audio signal or a signal derived from the audio signal by coherence enhancement using time variant weighting factors and to obtain a two-channel audio signal. The apparatus further includes a controller for controlling the time variant weighting factors by analyzing the audio signal so that different portions of the audio signal are multiplied by different weighting factors and the two-channel audio signal has a time variant degree of decorrelation.

Audio coherence enhancement by controlling time variant weighting factors for decorrelated signals

An apparatus for generating a stereo side signal having a first side channel and a second side channel from a stereo input signal having a first input channel and a second input channel is provided. The apparatus has a modification information generator for generating modification information based on mid-side information. Furthermore, the apparatus has a signal manipulator being adapted to manipulate the first input channel based on the modification information to obtain the first side channel and being adapted to manipulate the second input channel based on the modification information to obtain the second side channel. The modification information generator has a spectral weights generator for generating the modification information by generating a first spectral weighting factor based on a mono mid signal and on a mono side signal of the stereo input signal.

Method and apparatus for decomposing a stereo recording using frequency-domain processing employing a spectral weights generator

An apparatus for improving a perceived quality of sound reproduction of an audio output signal is provided. The apparatus has an active noise cancellation unit for generating a noise cancellation signal based on an environmental audio signal, wherein the environmental audio signal has noise signal portions, the noise signal portions resulting from recording environmental noise. Moreover, the apparatus has a residual noise characteristics estimator for determining a residual noise characteristic depending on the environmental noise and the noise cancellation signal. Furthermore, the apparatus has a perceptual noise compensation unit for generating a noise-compensated signal based on an audio target signal and based on the residual noise characteristic. Moreover, the apparatus has a combiner for combining the noise cancellation signal and the noise-compensated signal to obtain the audio output signal.

Apparatus and method for improving the perceived quality of sound reproduction by combining active noise cancellation and a perceptual noise compensation

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Erlangen, Germany

Patrick Gampp