Bi-directional Prediction Coding Single Motion Vector
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Solution Overview
Problem
Conventional video coding systems require a high number of motion vectors to be coded for bi-directional prediction, leading to increased computation complexity and bit rate, which is inefficient especially for low bit rate video transmission.
Innovation Solution
A bi-directional prediction method that codes a single motion vector and calculates another, using forward and backward candidate motion vectors within a given searching scope and threshold, without enhancing the complexity of searching for a matching block, allowing for accurate motion vector prediction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If bi-directional prediction is used to improve prediction accuracy, then prediction performance is improved, but the number of motion vectors to be coded increases
Solution Approach 1:
The patent extracts only the necessary motion information by coding a single motion vector for B-frames instead of separate forward and backward motion vectors. The bi-directional prediction is achieved by combining the coded motion vector with reference picture selection, eliminating redundant motion vector coding while preserving prediction accuracy.
Solution Approach 2:
The patent merges the forward and backward prediction functions into a single motion vector coding scheme. By combining motion vector prediction with reference picture indication, the system achieves bi-directional prediction functionality through integrated coding rather than separate forward and backward motion vector coding.
2Measurement precision
If multiple motion vectors are coded for bi-directional prediction, then prediction accuracy is improved, but computation complexity increases
Solution Approach 1:
The patent extracts only the essential motion information needed for bi-directional prediction by coding a single motion vector. The reference picture selection mechanism extracts the directional information (forward or backward reference) without requiring separate motion vector coding for each direction, thereby reducing computational complexity.
Solution Approach 2:
Instead of coding separate motion vectors for forward and backward directions and then combining them, the patent inverts the approach by coding a single motion vector and using reference picture selection to determine the prediction direction. This inversion simplifies the computational process while maintaining prediction accuracy.
3Productivity
If bi-directional prediction with multiple motion vectors is used, then compression efficiency is improved, but bit rate increases
Solution Approach 1:
The patent extracts only the necessary motion information by coding a single motion vector for B-frames. The reference picture selection mechanism provides the additional directional information needed for bi-directional prediction without requiring extra motion vector bits, thereby maintaining compression efficiency while reducing bit rate.
Solution Approach 2:
The patent discards the redundant separate forward and backward motion vector coding in favor of a single motion vector. The bi-directional prediction functionality is recovered through the combination of the coded motion vector with reference picture indication, achieving the same compression efficiency with lower bit rate.
Data Source
AI summary
The invention discloses a bi-directional prediction method for video coding/decoding. When bi-directional prediction coding at the coding end, firstly the given forward candidate motion vector of the current image block is obtained for every image block of the current B-frame; the backward candidate motion vector is obtained through calculation, and the candidate bi-directional prediction reference block is obtained through bi-directional prediction method; the match is computed within the given searching scope and/or the given matching threshold; finally the optimal matching block is selected to determine the final forward motion vector, and the backward motion vector and the block residual. The present invention achieves the object of bi-directional prediction by coding a single motion vector, furthermore, it will not enhance the complexity of searching for a matching block at the coding end, and may save amount of coding the motion vector and represent the motion of the objects in video more actually. The present invention realizes a new prediction coding type by combining the forward prediction coding with the backward.