Method for encoding multi-channel signal and encoder

Patent metadata

Field	Value
Publication number	US-11217257-B2
Application number	US-202016818612-A
Country	US
Kind code	B2
Filing date	Mar 13, 2020
Priority date	Aug 10, 2016
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

A method for encoding a multi-channel signal and an encoder, where the encoding method includes obtaining a multi-channel signal of a current frame, determining an initial inter-channel time difference (ITD) value of the current frame, controlling, based on characteristic information of the multi-channel signal, a quantity of target frames that are allowed to appear continuously, where the characteristic information includes at least one of a signal-to-noise ratio of the multi-channel signal or a peak feature of cross correlation coefficients of the multi-channel signal, and an ITD value of a previous frame of the target frame is reused as an ITD value of the target frame, determining an ITD value of the current frame based on the initial ITD value and the quantity of target frames allowed to appear continuously, and encoding the multi-channel signal based on the ITD value of the current frame.

First claim

What is claimed is:

1. A computer program product comprising computer-executable instructions stored on a non-transitory computer-readable medium that, when executed by a processor, cause a device to:
obtain a multi-channel signal of a current frame;
determine an initial inter-channel time difference (ITD) value of the current frame;
control a quantity of target frames allowed to appear continuously based on characteristic information of the multi-channel signal, wherein the characteristic information comprises at least one of a signal-to-noise ratio of the multi-channel signal or a peak feature of cross correlation coefficients of the multi-channel signal, and wherein an ITD value of a previous frame of a target frame is reused as an ITD value of the target frame;
determine an ITD value of the current frame based on the initial ITD value of the current frame and the quantity of target frames allowed to appear continuously; and
encode the multi-channel signal based on the ITD value of the current frame.

2. The computer program product of claim 1 , wherein before the computer-executable instructions cause the device to control the quantity of target frames allowed to appear continuously, the computer-executable instructions further cause the device to determine the peak feature of the cross correlation coefficients based on an amplitude of a peak value of the cross correlation coefficients and an index of a peak position of the cross correlation coefficients.

3. The computer program product of claim 2 , wherein the computer-executable instructions further cause the device to:
determine a peak amplitude confidence parameter based on the amplitude of the peak value, wherein the peak amplitude confidence parameter represents a confidence level of the amplitude of the peak value;
determining a peak position fluctuation parameter based on an ITD value corresponding to the index of the peak position of the cross correlation coefficients and an ITD value of a previous frame of the current frame, wherein the peak position fluctuation parameter represents a difference between the ITD value corresponding to the index of the peak position and the ITD value of the previous frame; and
determining the peak feature of the cross correlation coefficients based on the peak amplitude confidence parameter and the peak position fluctuation parameter.

4. The computer program product of claim 3 , wherein the computer-executable instructions further cause the device to determine, as the peak amplitude confidence parameter, a ratio of a difference between an amplitude value of the peak value of the cross correlation coefficients and an amplitude value of a second largest value of the cross correlation coefficients to the amplitude value of the peak value of the cross correlation coefficients.

5. The computer program product of claim 3 , wherein the computer-executable instructions further cause the device to determine, as the peak position fluctuation parameter, an absolute value of a difference between the ITD value corresponding to the index of the peak position of the cross correlation coefficients and the ITD value of the previous frame.

6. The computer program product of claim 1 , wherein the computer-executable instructions further cause the device to:
control the quantity of the target frames allowed to appear continuously based on the peak feature of the cross correlation coefficients; and
adjust at least one of a target frame count or a threshold of the target frame count to reduce the quantity of the target frames allowed to appear continuously when the peak feature of the cross correlation coefficients meets a preset condition, wherein the target frame count represents a quantity of target frames that have currently appeared continuously, and wherein the threshold of the target frame count indicates the quantity of the target frames allowed to appear continuously.

7. The computer program product of claim 6 , wherein the computer-executable instructions further cause the device to:
control the quantity of the target frames allowed to appear continuously based on the peak feature of the cross correlation coefficients only when the signal-to-noise ratio of the multi-channel signal does not meet a preset signal-to-noise ratio condition, and
stop reusing an ITD value of a previous frame as the ITD value of the current frame when the signal-to-noise ratio of the multi-channel signal meets the preset signal-to-noise ratio condition.

8. The computer program product of claim 1 , wherein the computer-executable instructions further cause the device to:
determine whether the signal-to-noise ratio of the multi-channel signal meets a preset signal-to-noise ratio condition;
control the quantity of the target frames allowed to appear continuously when the signal-to-noise ratio of the multi-channel signal does not meet the preset signal-to-noise ratio condition based on the peak feature of the cross correlation coefficients; and
stop reusing an ITD value of a previous frame as the ITD value of the current frame when the signal-to-noise ratio of the multi-channel signal meets the preset signal-to-noise ratio condition.

9. The computer program product of claim 8 , wherein the computer-executable instructions further cause the device to increase a target frame count such that a value of the target frame count is greater than or equal to a threshold of the target frame count, wherein the target frame count represents a quantity of target frames that have currently appeared continuously, and wherein the threshold of the target frame count indicates the quantity of the target frames allowed to appear continuously.

10. An encoder, comprising:
an obtaining circuit, configured to obtain a multi-channel signal of a current frame;
a first determining circuit, configured to determine an initial inter-channel time difference (ITD) value of the current frame;
a control circuit, configured to control a quantity of target frames allowed to appear continuously based on characteristic information of the multi-channel signal, wherein the characteristic information comprises at least one of a signal-to-noise ratio of the multi-channel signal or a peak feature of cross correlation coefficients of the multi-channel signal, and wherein an ITD value of a previous frame of a target frame is reused as an ITD value of the target frame;
a second determining circuit, configured to determine an ITD value of the current frame based on the initial ITD value of the current frame and the quantity of target frames that are allowed to appear continuously; and
an encoding circuit, configured to encode the multi-channel signal based on the ITD value of the current frame.

11. The encoder according to claim 10 , wherein the encoder further comprises a third determining circuit, configured to determine the peak feature of the cross correlation coefficients based on an amplitude of a peak value of the cross correlation coefficients and an index of a peak position of the cross correlation coefficients signal.

12. The encoder according to claim 11 , wherein the third determining circuit is further configured to:
determine a peak amplitude confidence parameter based on the amplitude of the peak value, wherein the peak amplitude confidence parameter represents a confidence level of the amplitude of the peak value;
determine a peak position fluctuation parameter based on an ITD value corresponding to the index of the peak position of the cross correlation coefficients, and an ITD value of a previous frame of the current frame, wherein the peak position fluctuation parameter represents a difference between the ITD value corresponding to t

Assignees

• Huawei Tech Co Ltd

Inventors

• Li Haiting
• Liu Zexin
• Zhang Xingtao
• Miao Lei

Classifications

• H04S2420/03

  Application of parametric coding in stereophonic audio systems · CPC title

• H04S3/00

  Systems employing more than two channels, e.g. quadraphonic (H04S5/00, H04S7/00 take precedence) · CPC title

• G10L25/06

  the extracted parameters being correlation coefficients · CPC title

• G10L19/0204

  using subband decomposition · 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