Entropy Decoder Context Variable Storage for Dependent Slice Segments
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional video codecs face challenges in efficiently encoding and decoding high-resolution video content, particularly in managing context variables across slice segments during entropy encoding and decoding, which affects data compression and synchronization.
Innovation Solution
A video entropy decoding apparatus that utilizes context information from nearby data to optimize entropy encoding and decoding, especially by storing context variables after the completion of each slice segment's maximum coding unit (LCU) processing, and using information indicating a subset offset to reduce data size and enhance synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If context variables are stored for all slice segments, then decoding accuracy is improved, but memory usage and processing complexity increase
Solution Approach 1:
The patent divides slice segments into two categories: independent slice segments and dependent slice segments. This segmentation allows different handling strategies for different segment types, storing context variables only for independent segments to reduce complexity while maintaining decoding accuracy where needed.
Solution Approach 2:
The patent applies different quality levels of context variable storage to different regions (slice segments) based on their independence characteristics. Independent slice segments receive full context variable storage for accurate decoding, while dependent slice segments use reference to parent segments, optimizing the balance between accuracy and complexity locally.
2Reliability
If context variables are initialized for each independent slice segment, then decoding independence is improved, but data size and processing overhead increase
Solution Approach 1:
The patent segments the video data structure into independent slice segments that can be decoded autonomously. Each independent slice segment contains necessary context variables to ensure decoding independence without requiring full initialization for all segments, reducing overall data size.
Solution Approach 2:
Instead of fully initializing context variables for all slice segments, the patent applies partial initialization only where necessary (independent segments). This partial action maintains decoding independence for critical segments while avoiding redundant data duplication across all segments.
3Productivity
If arithmetic coding-based entropy encoding is used, then compression ratio is improved, but computational complexity increases
Solution Approach 1:
The patent segments the encoding process into distinct phases: context variable initialization, arithmetic coding execution, and context variable storage. This segmentation allows efficient management of computational resources by focusing complex arithmetic coding operations on independent slice segments only, reducing overall computational complexity while maintaining high compression ratios.
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3~4
AI summary
Provided is a video decoding apparatus comprising an obtaining unit configured for obtaining, from a bitstream, information about a maximum size of a coding unit and first information indicating whether a dependent slice segment is permitted to be included in a picture. The apparatus includes a decoder configured for determining at least one maximum coding unit included in a first slice segment, based on a maximum coding unit size which is determined by using the information about the maximum size. The obtaining unit is further configured for obtaining, from the bitstream, second information indicating whether a current maximum coding unit is at an end of the first slice segment or not. The decoder is further configured for storing a context variable of the first slice segment if the first information indicates that a dependent slice segment is permitted to be included in the picture and the second information indicates that a current maximum coding unit is at an end of the first slice segment.