Motion Vector Prediction Candidate Subsets in Video Coding
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Solution Overview
Problem
Current video coding technologies face challenges in efficiently reducing the redundancy of motion vectors, leading to increased bandwidth and storage requirements, particularly in high-resolution video applications.
Innovation Solution
The implementation of adaptive motion vector resolution (AMVR) and motion vector prediction derivation techniques, which restrict MVP candidates to a subset based on AMVR indices, reducing signaling flags and bits required for encoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If motion vector prediction is performed using all available candidates, then prediction accuracy is improved, but signaling overhead and computational complexity increase
Solution Approach 1:
The patent segments the motion vector prediction candidate list into two distinct parts: a first subset containing spatial neighbors and a second subset containing temporal neighbors. By separating these candidates and applying different selection strategies to each subset, the patent reduces the signaling overhead while maintaining prediction accuracy. The encoder can selectively signal candidates from each subset based on their availability and relevance, rather than signaling all candidates uniformly.
Solution Approach 2:
The patent implements dynamic candidate selection where the composition of the motion vector predictor candidate list adapts based on the specific video content and block characteristics. The encoder dynamically determines which spatial and temporal neighbors are available and relevant, constructing a customized candidate list for each block. This dynamic approach allows the system to maintain high prediction accuracy while minimizing signaling overhead by only including necessary candidates.
2Productivity
If adaptive motion vector resolution is applied, then compression ratio is improved, but computational complexity increases
Solution Approach 1:
The patent applies different motion vector resolutions to different regions and blocks based on their specific characteristics. Rather than using a uniform resolution across the entire video stream, the system selectively applies adaptive motion vector resolution where beneficial. The encoder evaluates each block's motion characteristics and applies appropriate resolution levels, reducing overall computational complexity while maintaining high compression ratios in regions that benefit from adaptive resolution.
Solution Approach 2:
The patent changes the precision parameter of motion vectors adaptively based on content characteristics. The system adjusts motion vector precision (e.g., quarter-pixel, half-pixel, full-pixel) dynamically according to the complexity of motion in different blocks. This parameter adaptation allows the system to achieve higher compression ratios by using lower precision where appropriate, while maintaining necessary precision in high-motion regions, thereby balancing compression efficiency with computational complexity.
Data Source
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AI summary
Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes processing circuitry. The processing circuitry decodes prediction information of a current block from a coded video bitstream. The prediction information is indicative of an inter prediction mode that performs inter prediction based on a motion vector predictor selected from a list of candidates and a motion vector difference. Then, the processing circuitry decodes precision information of the motion vector difference and derives the motion vector predictor from a subset of the list of candidates when the precision information is indicative of a specific precision. Then, the processing circuitry reconstructs a sample of the current block according to the motion vector predictor and the motion vector difference.