Stereo Signal Encoding Window Modification for Linear Prediction Accuracy

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Solution Overview

Problem

The existing time-domain stereo encoding methods face inaccuracies in linear prediction due to manual reconstruction of forward signals, leading to differences between predicted and real linear prediction coefficients, which affect encoding quality.

Innovation Solution

A stereo signal encoding method that determines a modified linear prediction analysis window based on an inter-channel time difference and a transition segment, reducing the impact of manually reconstructed signals by attenuating values in the window, thereby improving prediction accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manual reconstruction of forward signal is performed on target sound channel, then delay alignment is achieved, but linear prediction accuracy deteriorates due to large difference between manually determined signal and real signal

Engineering Contradiction:

Improvedelay alignment accuracyVSAvoidlinear prediction coefficient accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent modifies the linear prediction analysis window parameters by determining an attenuation window length based on inter-channel time difference and transition segment length, then applying attenuation to specific points in the window. This parameter modification allows the system to account for manually reconstructed signal portions while maintaining accurate linear prediction coefficients

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces a modified linear prediction analysis window as an intermediary element between the manually reconstructed target sound channel signal and the linear prediction analysis process. This window acts as a mediator that reduces the impact of discrepancies between manually determined signals and real signals on prediction accuracy

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If attenuation window is applied to modify linear prediction analysis window, then linear prediction accuracy is improved, but encoding process complexity increases

Engineering Contradiction:

Improvelinear prediction coefficient accuracyVSAvoidencoding process complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent determines the attenuation window length using a formula based on inter-channel time difference and transition segment length, then applies systematic attenuation to specific points in the linear prediction analysis window. This parameter-based approach improves prediction accuracy while maintaining a relatively simple and systematic encoding process

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11636863B2Stereo signal encoding method and encoding apparatus

Publication Date: 2023.04.25 HUAWEI TECH CO LTD

AI summary

A stereo signal encoding method includes determining a window length of an attenuation window based on an inter-channel time difference; determining a modified linear prediction analysis window based on the window length of the attenuation window, where values of at least some points from a point (L−sub_window_len) to a point (L−1) in the modified linear prediction analysis window are less than values of corresponding points from a point (L−sub_window_len) to a point (L−1) in an initial linear prediction analysis window, and the window length of the modified linear prediction analysis window is equal to a window length of the initial linear prediction analysis window; and performing linear prediction analysis on a to-be-processed sound channel signal based on the modified linear prediction analysis window.