Motion Vector Prediction Mode Selection for Video Encoding
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Solution Overview
Problem
Current video coding technologies, such as MPEG-4 H.264/MPEG-4 AVC, face inefficiencies in encoding and decoding motion vectors, particularly in predicting motion vectors for current blocks, which can lead to increased overhead and decreased compression ratios due to the need to encode information about multiple motion vector predictors.
Innovation Solution
The method involves selecting between an explicit mode and an implicit mode for encoding motion vector predictors, where the explicit mode encodes information about specific predictors and the implicit mode generates predictors based on pixels in adjacent encoded areas, allowing for adaptive prediction and reduced overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple motion vector predictors are encoded explicitly, then prediction accuracy is improved, but encoding overhead increases
Solution Approach 1:
The patent changes the encoding parameter from explicit motion vector predictor values to an implicit mode indicator that triggers template-based generation. This parameter change reduces the number of bits required to encode motion vector information while maintaining prediction accuracy through adaptive template matching.
Solution Approach 2:
The patent extracts only the essential information needed for motion vector prediction by using a mode indicator instead of encoding complete predictor vectors. This extraction approach removes redundant data while preserving the core predictive capability through template-based reconstruction at the decoder.
2Loss of information
If implicit mode with template searching is used, then encoding overhead is reduced, but prediction accuracy may decrease
Solution Approach 1:
The patent performs preliminary actions by pre-defining template regions around the current block and preparing candidate motion vectors from previously decoded blocks. This preliminary preparation enables the decoder to quickly generate accurate motion vector predictors through template matching without extensive searching, maintaining both low overhead and high accuracy.
Solution Approach 2:
The patent applies local quality by using spatially localized templates adjacent to the current block for motion vector prediction. The template matching process focuses computational effort on locally relevant regions, ensuring high prediction accuracy for the specific block context while keeping the overall encoding efficient.
3Productivity
If mode selection is performed for each block, then compression efficiency is improved, but processing complexity increases
Solution Approach 1:
The patent applies partial action by performing mode selection only when beneficial, using simple criteria to determine when to switch between explicit and implicit modes. This selective approach achieves most of the potential compression gains without the full complexity of exhaustive mode evaluation for every block, balancing efficiency and complexity.
Data Source
AI summary
Provided are methods and apparatuses for encoding and decoding a motion vector. The method of encoding a motion vector includes: selecting a mode from among a first mode in which information indicating a motion vector predictor of at least one motion vector predictor is encoded and a second mode in which information indicating generation of a motion vector predictor based on pixels included in a previously encoded area adjacent to a current block is encoded; determining a motion vector predictor of the current block according to the selected mode and encoding information about the motion vector predictor of the current block; and encoding a difference vector between a motion vector of the current block and the motion vector predictor of the current block.