Stereo Encoding Scaling Factor via Sub-band Cross Correlation

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Solution Overview

Problem

Existing stereo encoding technologies require high calculation complexity and system resources to determine an optimal scaling factor, leading to inefficiencies in processing.

Innovation Solution

A method that involves obtaining energy relation coefficients, calculating energy sums and cross correlations of sub-bands, and using these results to directly determine a scaling factor for encoding stereo left and right channel signals, thereby reducing computational complexity and resource usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If all possible scaling factors are calculated and compared to determine an optimal scaling factor, then the stereo encoding performance is improved, but the calculation amount and complexity increase significantly

Engineering Contradiction:
Improvestereo encoding performanceVSAvoidcalculation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the stereo signal into multiple sub-bands and processes each sub-band separately to determine scaling factors. Instead of calculating all possible scaling factors for the entire signal, the method divides the frequency spectrum into sub-bands and determines scaling factors for each sub-band independently, significantly reducing the overall calculation complexity while maintaining encoding performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the approach from determining a single global scaling factor to determining multiple sub-band specific scaling factors. By introducing sub-band decomposition and processing, the method transforms the problem from a single-parameter optimization to a multi-parameter approach that reduces computational burden while preserving stereo quality.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If all possible scaling factors are calculated and compared to determine an optimal scaling factor, then the stereo encoding performance is improved, but the system resources occupied increase

Engineering Contradiction:
Improvestereo encoding performanceVSAvoidsystem resources
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent segments the stereo signal into multiple sub-bands and processes each sub-band separately to determine scaling factors. Instead of calculating all possible scaling factors for the entire signal, the method divides the frequency spectrum into sub-bands and determines scaling factors for each sub-band independently, significantly reducing the overall calculation complexity while maintaining encoding performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by determining scaling factors only for necessary sub-bands rather than processing the entire frequency spectrum uniformly. The method focuses computational resources on sub-bands that contribute most to stereo perception, avoiding unnecessary calculations in less critical frequency regions.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP2793228B1Stereo encoding method, stereo encoding device
Publication Date: 2019.05.08 HUAWEI TECH CO LTD
  • EP2793228B1 patent drawingFigure 1~2
  • EP2793228B1 patent drawingFigure 3~4
  • EP2793228B1 patent drawingFigure 5~6

AI summary

A stereo encoding method, a stereo encoding device, and an encoder are provided. The stereo encoding method includes: obtaining a left channel energy relation coefficient and a right channel energy relation coefficient; obtaining a left energy sum and a right energy sum respectively; performing cross correlation between sub-bands of a first monophonic signal at a wave trough and sub-bands of the left channel signal according to the left channel energy relation coefficient, and performing cross correlation between sub-bands of the first monophonic signal at the wave trough and sub-bands of the right channel signal according to the right channel energy relation coefficient; obtaining a scaling factor by using the left energy sum, the right energy sum, and cross correlation results; and encoding the stereo left and right channel signals according to the scaling factor.