Video Coefficient Scan Order Adaptation for Macroblock Decoding
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Solution Overview
Problem
Existing video signal compression methods face inefficiencies due to inadequate or excessive elimination of spatial and temporal redundancies, leading to suboptimal compression and decoding rates.
Innovation Solution
Adaptive definition of unit block sizes for transform processes, use of flag information to indicate block sizes and types, application of suitable transforms like DCT or KLT, and scanning order optimization for each macroblock to eliminate redundancy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If spatial redundancy and temporal redundancy are excessively eliminated to improve compression rate, then compression rate is improved, but decoding rate degrades due to insufficient information for decoding
Solution Approach 1:
The patent applies parameter changes by adaptively selecting transform block sizes (4x4, 8x8, 16x16) and transform types (DST, DCT, KLT) based on the characteristics of the video signal. This allows the system to optimize the balance between compression rate and decoding quality by adjusting transformation parameters according to actual signal conditions, thereby improving compression efficiency while maintaining sufficient information for accurate decoding.
2Device complexity
If a fixed transform block size is used to simplify the decoding process, then device complexity is reduced, but coding efficiency is lowered due to inability to adapt to different video content
Solution Approach 1:
The patent implements dynamics by making the transform block size and transform type variable rather than fixed. The system dynamically adapts the transform parameters based on the prediction mode and characteristics of each macroblock, allowing optimal performance for different video content while maintaining a manageable decoding complexity through standardized adaptation rules.
Solution Approach 2:
The patent applies local quality by allowing different transform block sizes and transform types to be applied to different regions (macroblocks) within the video signal. This enables locally optimized transformation that adapts to the specific characteristics of each region, improving overall coding efficiency without requiring complete reprocessing of the entire video stream.
3Device complexity
If a single transform type is used for all macroblocks to reduce processing overhead, then device complexity is reduced, but coding efficiency is degraded due to mismatch between transform type and prediction mode
Solution Approach 1:
The patent applies parameter changes by selecting different transform types (DST, DCT, KLT) based on the prediction mode of each macroblock. This adaptive selection optimizes the transformation process for different types of video content and prediction scenarios, improving coding efficiency while keeping the decision logic based on simple mode matching that does not significantly increase processing overhead.
Data Source
AI summary
The present invention relates to a method for decoding a video signal, comprising the steps of: acquiring a transform size flag of the current macroblock from a video signal; checking the number of non-zero transform coefficients at each pixel position in a first transform block which corresponds to the transform size flag; changing a scan order of the first transform block by prioritizing the position of the pixel having the greatest number of the nonzero transform coefficients in the first transform block; determining the number of the non-zero transform coefficients at each pixel position in a second transform block, and setting the changed scan order of the first transform block as an initialized scan order of the second transform block; adding the number of the non-zero transform coefficients at each pixel position in the first transform block and the number of the non-zero transform coefficients at each pixel position in the second transform block, and changing the scan order of the second transform block by prioritizing the position of the pixel having the greatest number of the nonzero transform coefficients; and decoding the transform coefficients arranged in the scan order changed in the previous step, wherein the first transform block and the second transform block have sizes corresponding to the transform size flag, and are contained in the current macroblock.