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

Patent metadata

Field	Value
Publication number	US-12380899-B2
Application number	US-202318200190-A
Country	US
Kind code	B2
Filing date	May 22, 2023
Priority date	Jul 22, 2013
Publication date	Aug 5, 2025
Grant date	Aug 5, 2025

Abstract

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.

First claim

The invention claimed is:

1. An audio decoder for providing at least four audio channel signals on the basis of an encoded representation,
wherein the audio decoder 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;
wherein the audio decoder is configured to provide a first audio channel signal and a second audio channel signal on the basis of a first signal and using the first residual signal;
wherein the audio decoder is configured to provide a third audio channel signal and a fourth audio channel signal on the basis of a second signal and using the second residual signal; and
wherein the audio decoder is implemented using a hardware apparatus, a computer, or a combination of a hardware apparatus and a computer.

2. The audio decoder according to claim 1 , wherein the audio decoder is configured to provide the first signal and the second signal on the basis of a jointly-encoded representation of the first signal and the second signal using a multi-channel decoding.

3. The audio decoder according to claim 1 , wherein the audio decoder is configured to provide the first residual signal and the second residual signal on the basis of the jointly encoded representation of the first residual signal and of the second residual signal using a prediction-based multi-channel decoding.

4. The audio decoder according to claim 1 , wherein the audio decoder is configured to provide the first residual signal and the second residual signal on the basis of the jointly encoded representation of the first residual signal and of the second residual signal using a residual-signal-assisted multi-channel decoding.

5. The audio decoder according to claim 3 , wherein the prediction-based multi-channel decoding is configured to evaluate a prediction parameter describing a contribution of a signal component, which is derived using a signal component of a previous frame, to the provision of the residual signals of the current frame.

6. The audio decoder according to claim 3 , wherein the prediction-based multi-channel decoding is configured to obtain the first residual signal and the second residual signal on the basis of a downmix signal of the first residual signal and of the second residual signal and on the basis of a common residual signal of the first residual signal and the second residual signal.

7. The audio decoder according to claim 6 , wherein the prediction-based multi-channel decoding is configured to apply the common residual signal with a first sign, to obtain the first residual signal, and to apply the common residual signal with a second sign, which is opposite to the first sign, to obtain the second residual signal.

8. The audio decoder according to claim 1 , wherein the audio decoder is configured to provide the first residual signal and the second residual signal on the basis of the jointly encoded representation of the first residual signal and of the second residual signal using a multi-channel decoding which is operative in a MDCT domain.

9. The audio decoder according to claim 1 , wherein the audio decoder is configured to provide the first residual signal and the second residual signal on the basis of the jointly encoded representation of the first residual signal and of the second residual signal using a USAC Complex Stereo Prediction.

10. The audio decoder according to claim 1 ,
wherein the audio decoder is configured to provide the first audio channel signal and the second audio channel signal on the basis of a first downmix signal and the first residual signal using a parameter-based residual-signal-assisted multi-channel decoding; and
wherein the audio decoder is configured to provide the third audio channel signal and the fourth audio channel signal on the basis of a second downmix signal and the second residual signal using a parameter-based residual-signal-assisted multi-channel decoding.

11. The audio decoder according to claim 10 , wherein the parameter-based residual-signal-assisted multi-channel decoding is configured to evaluate one or more parameters describing a desired correlation between two channels and/or level differences between two channels in order to provide the two or more audio channel signals on the basis of a respective one of the downmix signals and a corresponding one of the residual signals.

12. The audio decoder according to claim 1 , wherein the audio decoder is configure to provide the first audio channel signal and the 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 which is operative in a QMF domain; and
wherein the audio decoder is configured to provide the third audio channel signal and the 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 which is operative in the QMF domain.

13. The audio decoder according to claim 1 , wherein the audio decoder is configured to provide the first audio channel signal and the second audio channel signal on the basis of a first downmix signal and the first residual signal using a MPEG Surround 2-1-2 decoding or a Unified Stereo Decoding; and
wherein the audio decoder is configured to provide the third audio channel signal and the fourth audio channel signal on the basis of a second downmix signal and the second residual signal using a MPEG Surround 2-1-2 decoding or a Unified Stereo Decoding.

14. The audio decoder according to claim 1 , wherein the first residual signal and the second residual signal are associated with different horizontal positions of an audio scene or with different azimuth positions of the audio scene.

15. The audio decoder according to claim 1 , wherein the first audio channel signal and the second audio channel signal are associated with vertically neighboring positions of an audio scene, and
wherein the third audio channel signal and the fourth audio channel signal are associated with vertically neighboring positions of the audio scene.

16. The audio decoder according to claim 1 , wherein the first audio channel signal and the second audio channel signal are associated with a first horizontal position or azimuth position of an audio scene, and
wherein the third audio channel signal and the fourth audio channel signal are associated with a second horizontal position or azimuth position of the audio scene, which is different from the first horizontal position or the first azimuth position.

17. The audio decoder according to claim 1 , wherein the first residual signal is associated with a left side of an audio scene, and wherein the second residual signal is associated with a right side of an audio scene.

18. The audio decoder according to claim 17 ,
wherein the first audio channel signal and the second audio channel signal are associated with the left side of the audio scene, and
wherein the third audio channel signal and the fourth audio channel signal are associated with the right side of the audio scene.

19. The audio decoder according to claim 18 , wherein the first audio channel signal is associated with a lower left position of the audio scene,
wherein the second audio channel signal is associated with an upper left position of the audio scene,
wherein the third audio channel signal is associated with a lower right position of the audio scene, and
wherein the fourth audio channel signal is

Assignees

• Fraunhofer Ges Forschung

Inventors

• Dick Sascha
• Ertel Christian
• Helmrich Christian
• Hilpert Johannes
• Hoelzer Andreas
• Kuntz Achim

Classifications

• H04S2420/03

  Application of parametric coding in stereophonic audio systems · CPC title

• H04S3/008

  in which the audio signals are in digital form, i.e. employing more than two discrete digital channels (data reduction aspects thereof based on psychoacoustics G10L19/02) · CPC title

• H04S2400/03

  Aspects of down-mixing multi-channel audio to configurations with lower numbers of playback channels, e.g. 7.1 -> 5.1 (H04S2400/01 takes precedence) · CPC title

• H04S2400/01

  Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved · CPC title

• H04S7/30

  Control circuits for electronic adaptation of the sound field · CPC title