Apparatus and method for reproducing an audio signal, apparatus and method for generating a coded audio signal, computer program and coded audio signal

Abstract

An apparatus for reproducing an audio signal based on first data representing a coded version of a first portion of the audio signal in a first frequency band and second data representing side information on a second portion of the audio signal in a second frequency band, the second frequency band comprising frequencies higher than the first frequency band, comprises a first reproducer configured to reproduce the first portion of the audio signal based on the first data. A provider is configured to provide a patch signal in the second frequency band, wherein the patch signal is at least partially uncorrelated with respect to the first portion of the audio signal or is at least partially a decorrelated version of the first portion of the audio signal, which has been shifted to the second frequency band. A second reproducer is configured to reproduce the second portion of the audio signal in the second frequency band based on the second data and the patch signal. A combiner is configured to combine the reproduced first portion of the audio signal and the patch signal before the second portion of the audio signal is reproduced by the second reproducer or to combine the reproduced first portion of the audio signal and the reproduced second portion of the audio signal.

Description

technical field [0001] The present invention relates to a device, a method and a computer program to reproduce an audio signal, and in particular to a device, a method and a computer program to reproduce an audio signal in situations where the available data rate is reduced. Furthermore, the present invention relates to an apparatus, method and computer program for generating an encoded audio signal and a corresponding encoded audio signal. Background technique [0002] Perceptually adaptive audio signal coding to efficiently store and transmit these reduced data rate signals has gained acceptance in many fields. Coding algorithms are known, in particular MPEG 1 / 2, Layer 3 "MP3", MPEG2 / 4 Advanced Audio Coding (AAC) or MPEG-H Unified Speech and Audio Coding (USAC). The underlying encoding techniques, especially when reaching the lowest bit rates, result in reduced audio quality. Impairments are usually primarily caused by encoder-side limitations of the audio signal bandwid...

AI Technical Summary

Problems solved by technology

[0011] Known methods for harmonic bandwidth extension exhibit high complexity

On the other hand, bandwidth extension methods with reduced complexity exhibit quality loss

Especially at low bit rates, and in combination with the low bandwidth of the LF range, noise such as roughness and unpleasant timbres can occur

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