Apparatus for decoding an encoded audio signal with frequency tile adaption

Patent metadata

Field	Value
Publication number	US-11222643-B2
Application number	US-201916582336-A
Country	US
Kind code	B2
Filing date	Sep 25, 2019
Priority date	Jul 22, 2013
Publication date	Jan 11, 2022
Grant date	Jan 11, 2022

Abstract

Apparatus for decoding an encoded audio signal including an encoded core signal and parametric data, including: a core decoder for decoding the encoded core signal to obtain a decoded core signal; an analyzer for analyzing the decoded core signal before or after performing a frequency regeneration operation to provide an analysis result; and a frequency regenerator for regenerating spectral portions not included in the decoded core signal using a spectral portion of the decoded core signal, the parametric data, and the analysis result.

First claim

The invention claimed is:

1. Audio decoder for decoding an encoded audio signal comprising an encoded core audio signal and parametric data to obtain a decoded audio signal, the audio decoder comprising:
a core decoder configured for decoding the encoded core audio signal to acquire a decoded core audio signal;
a frequency regenerator configured for regenerating one or more spectral portions not comprised in the decoded core audio signal to acquire a preliminary regenerated signal using a spectral portion of the decoded core audio signal and using parameters for a preliminary regeneration, the preliminary regenerated signal comprising the one or more spectral portions, and
an analyzer configured for analyzing the one or more spectral portions of the preliminary regenerated signal to detect one or more artifact-creating signal portions in the one or more spectral portions,
wherein the frequency regenerator further comprises a manipulator configured for performing a further regeneration with parameters being different from the parameters for the preliminary regeneration in order to acquire a regenerated audio signal in which the one or more artifact-creating signal portions are reduced or eliminated,
wherein the parameters being different from the parameters for the preliminary regeneration comprise an amended transition frequency between patches or between a core-band and a first patch, or wherein the manipulator is configured to replace a tonal portion by a result of interpolating between a start and an end of the tonal portion or by randomly or pseudo-randomly generated spectral lines where the energy of the randomly or pseudo-randomly generated spectral lines is set so that the energy is similar to an adjacent non-tonal spectral part,
wherein the regenerated audio signal and the decoded core audio signal represent the decoded audio signal, and
wherein one of more of the analyzer, the core decoder, and the frequency regenerator is implemented, at least in part, by one of more hardware elements of the audio decoder.

2. Method of decoding an encoded audio signal comprising an encoded core audio signal and parametric data to obtain a decoded audio signal, the method comprising:
decoding the encoded core audio signal to acquire a decoded core audio signal;
regenerating one or more spectral portions not included in the decoded core audio signal using a spectral portion of the decoded core audio signal and using parameters for a preliminary regeneration to obtain a preliminary regenerated signal, the preliminary regenerated signal comprising the one or more spectral portions; and
analyzing the one or more spectral portions of the preliminary regenerated signal to detect one or more artifact-creating signal portions in the one or more spectral portions;
wherein the regenerating further comprises performing a further regeneration with parameters being different from the parameters for the preliminary regeneration in order to acquire a regenerated audio signal, in which the one or more artifact-creating signal portions are reduced or eliminated,
wherein the parameters being different from the parameters for the preliminary regeneration comprise an amended transition frequency between patches or between a core-band and a first patch, or wherein the manipulator is configured to replace a tonal portion by a result of interpolating between a start and an end of the tonal portion or by randomly or pseudo-randomly generated spectral lines where the energy of the randomly or pseudo-randomly generated spectral lines is set so that the energy is similar to an adjacent non-tonal spectral part,
wherein the regenerated audio signal and the decoded core audio signal represent the decoded audio signal, and
wherein one or more of the decoding the encoded core audio signal, the regenerating the one or more spectral portions, and the analyzing the preliminary regenerated signal is implemented, at least in part, by one or more hardware elements of an audio signal processing device.

3. A non-transitory computer readable medium comprising a computer program for performing, when running on a computer or a processor, a method of decoding an encoded audio signal comprising an encoded core audio signal and parametric data to obtain a decoded audio signal, the method comprising:
decoding the encoded core audio signal to acquire a decoded core audio signal;
regenerating one or more spectral portions not included in the decoded core audio signal using a spectral portion of the decoded core audio signal and using parameters for a preliminary regeneration to obtain a preliminary regenerated signal, the preliminary regenerated signal comprising the one or more spectral portions; and
analyzing the one or more spectral portions of the preliminary regenerated signal to detect one or more artifact-creating signal portions in the one or more spectral portions;
wherein the regenerating further comprises performing a further regeneration with parameters being different from the parameters for the preliminary regeneration in order to acquire a regenerated audio signal in which the one or more artifact-creating signal portions are reduced or eliminated,
wherein the parameters being different from the parameters for the preliminary regeneration comprise an amended transition frequency between patches or between a core-band and a first patch, or wherein the manipulator is configured to replace a tonal portion by a result of interpolating between a start and an end of the tonal portion or by randomly or pseudo-randomly generated spectral lines where the energy of the randomly or pseudo-randomly generated spectral lines is set so that the energy is similar to an adjacent non-tonal spectral part,
wherein the regenerated audio signal and the decoded core audio signal represent the decoded audio signal.

Assignees

• Fraunhofer Ges Forschung

Inventors

• Disch Sascha
• Geiger Ralf
• Helmrich Christian
• Nagel Frederik
• Neukam Christian
• Schmidt Konstantin
• Fischer Michael

Classifications

• G10L19/022

  Blocking, i.e. grouping of samples in time; Choice of analysis windows; Overlap factoring · CPC title

• G10L21/038

  using band spreading techniques · CPC title

• G10L19/008 Primary

  Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing · CPC title

• G10L25/21

  the extracted parameters being power information · CPC title

• G10L25/18

  the extracted parameters being spectral information of each sub-band · CPC title