Parallel CABAC Entropy Coding for Single-Slice H.264 Video
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Solution Overview
Problem
Conventional H.264 video processing systems face inefficiencies due to serial processing methods and hardware speed constraints, leading to sub-optimal motion search and inefficient entropy coding, which restricts the use of single-slice video frames and limits video quality.
Innovation Solution
Implementing a parallel processing scheme within the Context Adaptive Binary Arithmetic Coding (CABAC) module by eliminating nesting requirements, allowing the renormalization process to run independently of the encode-decision process, and using pipelined processors to facilitate simultaneous operations, thereby enabling single-slice per picture encoding and advanced rate control methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If serial processing methods are used in CABAC entropy coding, then implementation simplicity is maintained, but processing speed and efficiency deteriorate
Solution Approach 1:
The patent divides the CABAC processing into two independent parallel processes: encode-decision process and renormalization process. Each process handles specific tasks independently, eliminating the nested serial structure and enabling simultaneous execution to improve processing speed.
Solution Approach 2:
The patent transitions from a single-dimensional serial processing approach to a two-dimensional parallel processing architecture by introducing temporal parallelism between encode-decision and renormalization processes, effectively adding a time dimension to the processing workflow.
2Productivity
If nested loops are used for CABAC entropy coding, then coding accuracy is maintained, but processing efficiency and speed deteriorate
Solution Approach 1:
The patent performs renormalization operations in advance and independently of the encode-decision process. By preparing renormalization data beforehand and making it available through a buffer, the system eliminates waiting time and avoids nested loop structures that would otherwise be required.
Solution Approach 2:
The patent introduces a buffer as an intermediary component between the encode-decision process and renormalization process. This buffer stores renormalization data and allows the two processes to operate independently without direct coupling, eliminating the need for nested loops while maintaining data integrity.
3Productivity
If multiple slices are used per video frame, then hardware speed constraints are satisfied, but video quality and processing optimality deteriorate
Solution Approach 1:
The patent enables dynamic adjustment of slice configuration by removing the constraint that forced multiple slices per frame. The parallel processing architecture allows the system to adaptively use single-slice configuration when quality is prioritized, or switch to multiple slices when speed is critical, providing flexibility to optimize for different operational requirements.
Data Source
AI summary
An entropy coding apparatus. In a specific embodiment, the entropy coding apparatus includes a renormalization process and an encode-decision process that communicates with the renormalization process. The encode-decision process is adapted to run in parallel with the renormalization process without the renormalization process being nested therein. In a more specific embodiment, the entropy coding apparatus includes an entropy encoder that is H.264 compliant. The encode-decision process includes a first mechanism for pre-computing certain parameters to eliminate the need to nest the renormalization process within the encode-decision process. The renormalization process and the encode-decision process are components of a Context Adaptive Binary Arithmetic Coding (CABAC) module.