CABAC Delta-QP Binarization Using SAVS for Symmetric Bit Coding

Solution Overview

Problem

High Efficiency Video Coding (HEVC) standards face inefficiencies in Delta-QP (dQP) coding within Context-Based Adaptive Binary Arithmetic Coding (CABAC) due to asymmetric binarization methods that do not fully exploit the symmetric distribution of dQP values, leading to suboptimal bit allocation and increased complexity.

Innovation Solution

The proposed solution involves a Separate Absolute Value and Sign (SAVS) method for binarization, where a flag indicates non-zero dQP, and either the absolute value or sign of dQP is mapped using unary codes, allowing for separate encoding and combination of these values into a binary string, optimizing bit usage based on symmetric probability distributions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If asymmetric binarization method is used for dQP coding in CABAC, then the coding process is simpler to implement, but the number of bits required for encoding increases and coding efficiency decreases

Engineering Contradiction:

Improveimplementation simplicityVSAvoidcoding efficiency

Core Design Contradiction:

Ease of manufactureVSLoss of information

Solution Approach 1:

The patent segments the dQP value into two independent parts: sign bit and absolute value. The sign bit indicates the polarity (positive or negative) while the absolute value represents the magnitude. This segmentation allows each part to be encoded separately using optimized binarization schemes, improving overall coding efficiency while maintaining implementation clarity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the binarization parameter representation by introducing separate sign and absolute value fields. Instead of using a single asymmetric binarization scheme, the parameter is transformed into a structured format where the sign bit occupies one position and the absolute value is represented by additional bits, optimizing the bit allocation according to the statistical distribution of dQP values.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If asymmetric binarization method is used for dQP coding in CABAC, then the encoding process is faster, but the bit allocation becomes suboptimal and complexity increases

Engineering Contradiction:

Improveencoding speedVSAvoidbinarization complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the dQP value into two independent parts: sign bit and absolute value. The sign bit indicates the polarity (positive or negative) while the absolute value represents the magnitude. This segmentation allows each part to be encoded separately using optimized binarization schemes, improving overall coding efficiency while maintaining implementation clarity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the binarization parameter representation by introducing separate sign and absolute value fields. Instead of using a single asymmetric binarization scheme, the parameter is transformed into a structured format where the sign bit occupies one position and the absolute value is represented by additional bits, optimizing the bit allocation according to the statistical distribution of dQP values.

Inventive Principle:

Principle #35Parameter changes

3Loss of information

If separate absolute value and sign binarization is implemented, then bit usage is optimized according to symmetric distribution, but the encoding process becomes more complex

Engineering Contradiction:

Improvebit allocation efficiencyVSAvoidbinarization process complexity

Core Design Contradiction:

Loss of informationVSDevice complexity

Solution Approach 1:

The patent segments the dQP value into two independent parts: sign bit and absolute value. The sign bit indicates the polarity (positive or negative) while the absolute value represents the magnitude. This segmentation allows each part to be encoded separately using optimized binarization schemes, improving overall coding efficiency while maintaining implementation clarity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the binarization parameter representation by introducing separate sign and absolute value fields. Instead of using a single asymmetric binarization scheme, the parameter is transformed into a structured format where the sign bit occupies one position and the absolute value is represented by additional bits, optimizing the bit allocation according to the statistical distribution of dQP values.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11245902B2Binarization of DQP using separate absolute value and sign (SAVS) in CABAC

Publication Date: 2022.02.08 SONY GROUP CORP

AI summary

Video coding systems or apparatus utilizing context-based adaptive binary arithmetic coding (CABAC) during encoding and/or decoding, are configured according to the invention with an enhanced binarization of non-zero Delta-QP (dQP). During binarization the value of dQP and the sign are separately encoded using unary coding and then combined into a binary string which also contains the dQP non-zero flag. This invention capitalizes on the statistical symmetry of positive and negative values of dQP and results in saving bits and thus a higher coding efficiency.