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

Nils Werner

Bernd Edler

Sascha Disch

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

Embodiments provide an audio processor for processing an audio signal to obtain a subband representation of the audio signal. The audio processor is configured to perform a cascaded lapped critically sampled transform on at least two partially overlapping blocks of samples of the audio signal, to obtain a set of subband samples on the basis of a first block of samples of the audio signal, and to obtain a corresponding set of subband samples on the basis of a second block of samples of the audio signal. Further, the audio processor is configured to perform a weighted combination of two corresponding sets of subband samples, one obtained on the basis of the first block of samples of the audio signal and one obtained on the basis on the second block of samples of the audio signal, to obtain an aliasing reduced subband representation of the audio signal.

Perceptual audio coding with adaptive non-uniform time/frequency tiling using subband merging and the time domain aliasing reduction

An audio processor for processing an audio signal to acquire a subband representation thereof includes a cascaded lapped critically sampled transform stage and a time domain aliasing reduction stage, the former being configured to perform a cascaded lapped critically sampled transform on at least two partially overlapping blocks of samples of the audio signal, to acquire a set of subband samples on the basis of a first block of samples of the audio signal, and to acquire a corresponding set of subband samples on the basis of a second block of samples of the audio signal. The latter is configured to perform a weighted combination of two corresponding sets of subband samples, which are acquired on the basis of the first and second blocks of samples of the audio signal, respectively, to acquire an aliasing reduced subband representation of the audio signal.

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Erlangen, Germany

Nils Werner