IBC Predictor Candidate List Sizing for Video Decoding Efficiency
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Solution Overview
Problem
Existing video coding technologies face inefficiencies in motion vector prediction, particularly in intra block copy mode, leading to suboptimal compression ratios and decoding performance.
Innovation Solution
The method and apparatus enhance video decoding by constructing an intra block copy (IBC) predictor candidate list with a size determined by the number of IBC predictor candidates, allowing for greater flexibility and efficiency in selecting block vector predictors, thereby improving decoding accuracy and compression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a fixed-size predictor candidate list is used in IBC mode, then the decoding process is simple and fast, but the compression efficiency and decoding accuracy are suboptimal
Solution Approach 1:
The patent applies dynamics by making the predictor candidate list size variable rather than fixed. The list size is dynamically adjusted based on the number of available IBC predictor candidates, allowing the system to adapt between minimum size M and maximum size N, thereby optimizing compression efficiency while maintaining decoding performance
Solution Approach 2:
The patent changes the parameter of candidate list size from a fixed value to a variable range [M, N]. By signaling the actual list size to the decoder and allowing it to vary according to available candidates, the system achieves better compression efficiency without significantly increasing decoding complexity
2Measurement precision
If more IBC predictor candidates are included in the candidate list, then the prediction accuracy and video quality improve, but the signaling overhead and processing complexity increase
Solution Approach 1:
The patent applies partial action by including only the necessary number of IBC predictor candidates in the candidate list, rather than all possible candidates. The list size is set to max(M, min(AvailableCandidates, N)), which means including candidates only up to the maximum N or the available number, whichever is smaller, thereby balancing prediction accuracy with processing complexity
Solution Approach 2:
The system dynamically adjusts the candidate list size based on the number of available IBC predictors. When fewer than M candidates are available, the list is padded to size M; when between M and N candidates are available, the actual number is used; when more than N candidates are available, the list is limited to N. This dynamic adjustment optimizes the balance between prediction accuracy and processing complexity
Data Source
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AI summary
A method of video decoding includes receiving a coded video bitstream including a current picture. The method further includes- determining whether a current block included in the current picture is coded in intra block copy ( IBC) mode. The method further includes, in response to the current block being coded in the IBC mode, determining a number of IBC predictor candidates associated with the current block. The method further includes constructing an IBC predictor candidate list having a. size corresponding to the number of IBC predictor candidates. The method further includes selecting a block vector predictor from the IBC predictor candidate list. The method farther includes decoding a block vector associated with the current block, using the block vector predictor. The method further includes decoding the current block in accordance with the block vector.