CABAC dQP Binarization Using Separate Sign and Absolute Value
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current video coding standards, such as HEVC, face inefficiencies in encoding Delta-QP (dQP) due to asymmetric binarization methods that do not fully utilize 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) binarization method within CABAC, where a flag indicates non-zero dQP, and either the absolute value or sign 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
Engineering Contradiction Analysis
1Productivity
If asymmetric binarization method is used for dQP encoding, then the encoding process is simple, but the coding efficiency is suboptimal due to not utilizing the symmetric distribution of dQP values
Solution Approach 1:
The binarization process is segmented into two independent parts: sign binarization and magnitude binarization. The sign component (positive or negative) is encoded separately from the magnitude component, allowing each to be optimized independently according to the symmetric distribution characteristics of dQP values.
Solution Approach 2:
While the overall distribution of dQP values is symmetric, the binarization method introduces asymmetric treatment by separating sign and magnitude encoding. This allows the magnitude to use efficient unary coding while the sign uses a simple flag, optimizing bit usage based on the statistical properties of each component.
2Quantity of substance
If traditional unary coding is used for signed dQP, then the encoding method is straightforward, but the bit allocation is suboptimal
Solution Approach 1:
The encoding is divided into two segments: a sign flag (1 bit) indicating positive or negative, and a magnitude field encoded with unary coding. This segmentation reduces the total bit requirement compared to encoding the entire signed value with unary coding, while maintaining encoding simplicity.
Solution Approach 2:
The representation parameters are changed from direct unary encoding of signed integers to separate sign flag and magnitude encoding. This parameter transformation exploits the symmetric distribution of dQP values to reduce the average number of bits required for encoding.
Data Source
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.