Parallel CABAC Renormalization for Single-Slice H.264 Coding
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Solution Overview
Problem
Conventional H.264 video processing systems face inefficiencies due to serial processing operations and hardware speed constraints, limiting their ability to encode and decode high-quality video efficiently, particularly in applications requiring single-slice video frames.
Innovation Solution
The implementation of a parallel processing scheme within the Context Adaptive Binary Arithmetic Coding (CABAC) module, which eliminates nesting requirements and enables pipelined processing of encode-decision and renormalization processes, allowing for single-slice video encoding and improved rate control methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If serial processing operations are used in CABAC entropy coding, then hardware implementation is simpler, but processing speed and encoding efficiency deteriorate
Solution Approach 1:
The patent segments the CABAC encoding process into distinct functional modules including context modeling units, binary arithmetic coding units, and renormalization units. These modules are organized in a pipelined architecture where multiple stages process different data simultaneously, transforming the serial processing into parallel operations while maintaining modular hardware implementation
Solution Approach 2:
The patent introduces a temporal dimension through pipelining, organizing processing stages in sequence along the time axis. This allows multiple encode-decision and renormalization operations to occur simultaneously at different pipeline stages, effectively converting serial processing into parallel processing without increasing spatial complexity
2Productivity
If multiple slices are used to partition video frames, then hardware speed constraints are met, but video quality and encoding efficiency deteriorate
Solution Approach 1:
The patent performs preliminary renormalization operations in advance within the pipeline, preparing data structures and intermediate results before they are needed by subsequent encoding stages. This preliminary action eliminates the need for multiple slices by ensuring that all necessary processing is completed within a single slice's time window
3Productivity
If nested loops are used for CABAC entropy coding, then standard compliance is maintained, but processing throughput deteriorates
Solution Approach 1:
The patent extracts the control logic of nested loops from the processing flow and replaces it with explicit pipeline control signals and state machines. The iterative operations are unrolled and distributed across pipeline stages, removing the nested loop structure while maintaining standard compliance through equivalent computational operations
Data Source
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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.