Stereo Encoding Delay Adjustment via Signal Characteristic Analysis

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Solution Overview

Problem

Conventional stereo encoding methods introduce distortion during delay adjustment of left and right channel signals due to the lack of differentiation in stereo signal characteristics, leading to suboptimal synchronization and quality of the synthesized stereo signal.

Innovation Solution

A method and apparatus that extract the current interchannel delay and previous delay, perform adjustment frame judgment based on the stereo signal characteristics, and adjust the delay only when deemed suitable, reducing distortion by synchronizing signals effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If delay adjustment is performed on left and right channel signals whenever delays are different, then synchronization of channel signals is improved, but distortion is introduced due to lack of differentiation in signal characteristics

Engineering Contradiction:
Improvesynchronization of channel signalsVSAvoiddistortion in stereo signal
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by differentiating delay adjustment strategies based on signal characteristics. Voiced frames receive delay adjustment to ensure synchronization, while unvoiced frames skip delay adjustment to avoid distortion. This localized approach applies different quality levels of delay adjustment to different parts of the signal based on their inherent properties.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements dynamics by making the delay adjustment process adaptive rather than static. The system dynamically determines whether to perform delay adjustment on a frame-by-frame basis by detecting signal characteristics (voiced vs. unvoiced). This dynamic approach allows the system to optimize synchronization while minimizing distortion based on real-time signal conditions.

Inventive Principle:
Principle #15Dynamics

2Reliability

If delay adjustment is performed immediately when delays differ, then synchronization is achieved, but serious distortion is caused due to splicing and adding operations

Engineering Contradiction:
Improvesynchronization timingVSAvoidsignal quality during splicing and adding
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by differentiating delay adjustment strategies based on signal characteristics. Voiced frames receive delay adjustment to ensure synchronization, while unvoiced frames skip delay adjustment to avoid distortion. This localized approach applies different quality levels of delay adjustment to different parts of the signal based on their inherent properties.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements dynamics by making the delay adjustment process adaptive rather than static. The system dynamically determines whether to perform delay adjustment on a frame-by-frame basis by detecting signal characteristics (voiced vs. unvoiced). This dynamic approach allows the system to optimize synchronization while minimizing distortion based on real-time signal conditions.

Inventive Principle:
Principle #15Dynamics

3Reliability

If delay adjustment is performed without differentiating signal characteristics, then synchronization is improved, but distortion effects vary and worsen for signals with different characteristics

Engineering Contradiction:
Improvedelay synchronizationVSAvoidhandling of different stereo signal characteristics
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by differentiating delay adjustment strategies based on signal characteristics. Voiced frames receive delay adjustment to ensure synchronization, while unvoiced frames skip delay adjustment to avoid distortion. This localized approach applies different quality levels of delay adjustment to different parts of the signal based on their inherent properties.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements dynamics by making the delay adjustment process adaptive rather than static. The system dynamically determines whether to perform delay adjustment on a frame-by-frame basis by detecting signal characteristics (voiced vs. unvoiced). This dynamic approach allows the system to optimize synchronization while minimizing distortion based on real-time signal conditions.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2395504B1Stereo encoding method and apparatus
Publication Date: 2013.09.18 HUAWEI TECH CO LTD
  • EP2395504B1 patent drawingFigure 1~2
  • EP2395504B1 patent drawingFigure 3
  • EP2395504B1 patent drawingFigure 4

AI summary

A stereo encoding method and apparatus are provided, so as to reduce distortion caused by delay adjustment. The stereo encoding method includes: extracting a current interchannel delay of a stereo signal and a previous delay adjacent to the current interchannel delay; performing adjustment frame judgment according to characteristics of the current stereo signal when the current delay and the previous delay are different; and performing delay adjustment on the stereo signal by using the current interchannel delay if it is judged that a frame where the current delay occurs is an adjustment frame.