Adaptive Window Weighting for Multichannel Audio Delay Estimation

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Solution Overview

Problem

Existing audio coding devices inaccurately estimate inter-channel time differences due to excessive or insufficient smoothing of cross-correlation values, affecting the encoding and decoding quality of multi-channel audio signals.

Innovation Solution

A delay estimation method that uses an adaptive window function to weight cross-correlation coefficients based on delay track estimation values and smoothed inter-channel time difference information, adjusting the smoothing factor to improve accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a uniform smoothing factor is used for all cross-correlation values, then the processing is simple, but some cross-correlation values are excessively smoothed while others are insufficiently smoothed, leading to inaccurate inter-channel time difference estimation

Engineering Contradiction:
Improvesimplicity of smoothing processVSAvoidaccuracy of inter-channel time difference estimation
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent applies different smoothing factors to different cross-correlation values based on their specific characteristics. Instead of using a uniform smoothing factor, the system dynamically adjusts the smoothing factor for each cross-correlation value according to its magnitude and position, ensuring that each value receives appropriate smoothing treatment rather than excessive or insufficient smoothing.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces dynamic adjustment of smoothing factors based on the characteristics of cross-correlation values. The smoothing factor is not fixed but varies dynamically according to the specific cross-correlation value being processed, allowing the system to adapt to different situations and achieve optimal smoothing for each value.

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If excessive smoothing is applied to cross-correlation values, then the estimation is more stable, but the accuracy of inter-channel time difference estimation deteriorates

Engineering Contradiction:
Improvestability of estimationVSAvoidaccuracy of inter-channel time difference
Core Design Contradiction:
Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The patent changes the parameter of smoothing factor from a fixed uniform value to a dynamically adjusted value. By modifying the smoothing factor parameter based on the characteristics of each cross-correlation value, the system achieves the right balance between stability and accuracy, avoiding both excessive and insufficient smoothing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies localized smoothing treatment to different cross-correlation values by using different smoothing factors for different regions or magnitudes of cross-correlation values. This ensures that each value receives the appropriate degree of smoothing for its specific characteristics.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If insufficient smoothing is applied to cross-correlation values, then the accuracy is maintained, but the estimation becomes unstable and inaccurate

Engineering Contradiction:
Improveaccuracy of cross-correlation valueVSAvoidstability of estimation
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent adjusts the smoothing factor parameter dynamically to achieve appropriate smoothing. By changing the smoothing factor based on the specific characteristics of each cross-correlation value, the system ensures sufficient smoothing for stability while avoiding excessive smoothing that would harm accuracy.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4618076A1Delay estimation method and apparatus
Publication Date: 2025.09.17 HUAWEI TECH CO LTD
  • EP4618076A1 patent drawingFigure 1
  • EP4618076A1 patent drawingFigure 2~3
  • EP4618076A1 patent drawingFigure 4

AI summary

This application discloses a delay estimation method and apparatus, and belongs to the audio processing field. The method includes: determining a cross-correlation coefficient of a multi-channel signal of a current frame; determining a delay track estimation value of the current frame based on buffered inter-channel time difference information of at least one past frame; determining an adaptive window function of the current frame; performing weighting on the cross-correlation coefficient based on the delay track estimation value of the current frame and the adaptive window function of the current frame, to obtain a weighted cross-correlation coefficient; and determining an inter-channel time difference of the current frame based on the weighted cross-correlation coefficient, so as to resolve a problem that the cross-correlation coefficient is excessively smoothed or insufficiently smoothed, thereby improving accuracy of estimating an inter-channel time difference.