H.264 Video Encoding Algorithms for Transform Size and Motion Estimation
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Solution Overview
Problem
Current video encoding technologies, particularly those using the H.264/AVC standard, face challenges in efficiently selecting optimal transform sizes for macroblocks, performing motion estimation, and optimizing quantization parameters, leading to high computational complexity and visual artifacts in low bit-rate video coding.
Innovation Solution
The proposed solution introduces a complexity-based motion search cost function for motion estimation, a simplified rate-distortion optimization algorithm for transform size decision-making, and a method to accelerate the selection of optimal macroblock types, along with a quantization parameter modulation using a look-ahead refinement, to enhance encoding efficiency and visual quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional motion estimation algorithms are used, then motion search can be performed, but computational complexity increases and processing speed decreases
Solution Approach 1:
The patent divides the motion search process into multiple stages: coarse search using simplified cost functions, followed by fine search using full rate-distortion optimization only for candidate blocks that pass initial filtering. This segmentation reduces overall computational complexity while maintaining accuracy.
Solution Approach 2:
The patent applies different levels of processing quality to different regions and blocks. Full rate-distortion optimization is applied only to promising candidate blocks, while less computationally intensive methods are used for other blocks, optimizing the balance between speed and accuracy.
2Measurement precision
If full rate-distortion optimization is used for transform size decision, then optimal transform size can be selected, but processing time increases significantly
Solution Approach 1:
The patent performs preliminary analysis using simplified criteria (SAD or Hadamard transform) to identify promising candidate blocks before applying full rate-distortion optimization. This preliminary action filters out blocks that are unlikely to benefit from complex optimization, reducing overall processing time.
Solution Approach 2:
Instead of applying full rate-distortion optimization to all blocks, the patent applies it partially only to candidate blocks that meet certain criteria. This partial action approach maintains optimal transform size selection for important blocks while reducing total processing time.
3Measurement precision
If Intra 4×4 prediction modes are calculated for all macroblocks, then optimal prediction can be achieved, but encoding speed decreases
Solution Approach 1:
The patent applies full Intra 4×4 prediction mode calculation only to macroblocks that are likely to benefit from it, while using simpler prediction methods for other blocks. This local quality approach maintains high prediction accuracy where needed while improving overall encoding speed.
Solution Approach 2:
The patent performs partial Intra 4×4 prediction mode calculation, applying the computationally intensive process only to a subset of macroblocks that meet certain criteria, rather than to all macroblocks. This reduces total encoding time while maintaining accuracy for critical blocks.
4Measurement precision
If complex motion search cost functions are used, then motion estimation accuracy improves, but computational load increases
Solution Approach 1:
The patent segments the motion search into two phases: initial search using simplified cost functions to identify candidate blocks, and final refinement using complex cost functions only for those candidates. This segmentation reduces computational load while maintaining accuracy.
Solution Approach 2:
The patent introduces intermediate candidate block selection as a mediator between simple and complex motion search methods. This intermediary step filters blocks that need detailed analysis, reducing the computational load of complex cost functions while maintaining motion estimation accuracy for important blocks.
Data Source
AI summary
The video sequence encoding system with high compression efficiency is based on the H.264/AVC international video coding standard and is implementing proposed algorithms for: macroblock motion estimation; simplified rate-distortion optimization for transform size decision-making; acceleration of optimal macroblock type decision; modulation of quantization parameter with look-ahead refinement; and film-grain parameters calculation. The video encoding system comprises a motion estimation unit based on a measurement function for motion search of the matching texture block; a macroblock decision making unit; a pipeline processing module configured to accelerate complex transform; and a quantization parameter modulator configured to enhance the picture quality.