Enhanced Temporal Motion Vector Prediction for Video Decoding

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Solution Overview

Problem

The Alternative Temporal Motion Vector Prediction (ATMVP) technology in video coding faces issues with inaccurate motion information due to unreliable motion information from surrounding blocks, affecting coding performance.

Innovation Solution

The proposed solution involves determining an enhanced temporal motion vector prediction mode by obtaining index information from a bit stream, identifying matching blocks, and scaling motion information based on available forward and backward motion information to improve motion compensation accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ATMVP technology uses motion information of surrounding blocks to search for image blocks at corresponding positions, then temporal motion prediction can be performed, but the motion information becomes unreliable when surrounding block motion information is inaccurate

Engineering Contradiction:

Improvemotion information reliabilityVSAvoidprediction process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary actions by first determining the availability and accuracy of surrounding block motion information before proceeding with ATMVP. It checks whether surrounding blocks exist, whether they use inter prediction mode, and whether their motion information is reliable, thereby preparing the prediction process in advance to avoid using unreliable motion data.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of blindly trusting surrounding block motion information, the patent inverts the approach by explicitly checking for the unavailability or inaccuracy of such information. When surrounding block motion information is found to be unreliable or unavailable, the patent switches to alternative prediction methods, thereby preventing the propagation of erroneous motion data.

Inventive Principle:

Principle #13The other way round (Inversion)

2Adaptability or versatility

If multiple matching blocks are determined based on surrounding blocks, then more candidate modes are available, but the processing complexity increases

Engineering Contradiction:

Improveprediction mode flexibilityVSAvoidprocessing complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent determines up to three matching blocks (first, second, and third matching blocks) based on different surrounding blocks, which is more than the single block used in conventional ATMVP. This partial excessive action provides multiple candidate modes for selection, enhancing adaptability while managing complexity through structured processing of each candidate.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent employs feedback mechanisms by evaluating the availability and reliability of motion information from each surrounding block before incorporating it into the prediction process. It uses rate-distortion costs and availability flags to feedback on the quality of each candidate matching block, allowing the system to adaptively select the best prediction mode based on actual performance.

Inventive Principle:

Principle #23Feedback

3Measurement precision

If motion information is scaled to multiple reference pictures, then accurate motion compensation is achieved, but the computational load increases

Engineering Contradiction:

Improvemotion compensation accuracyVSAvoidcomputational power

Core Design Contradiction:

Measurement precisionVSPower

Solution Approach 1:

The patent changes parameters by scaling motion vector components based on temporal distances between reference pictures. It calculates scaling factors using temporal distances and applies these factors to motion vector components, thereby adapting the motion information to different reference picture timelines while maintaining accuracy through mathematically sound parameter transformations.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12256095B2Decoding methods and devices, and encoding methods and devices

Publication Date: 2025.03.18 HANGZHOU HIKVISION DIGITAL TECHNOLOGY CO LTD

AI summary

The present disclosure provides decoding methods, encoding methods, apparatuses and devices. A decoding method includes: obtaining index information of an enhanced temporal motion vector prediction mode from a bit stream of a current block when it is determined that an enhanced temporal motion vector prediction technology is enabled for the current block; determining one or more matching blocks of the current block; determining candidate enhanced temporal motion vector prediction modes based on the one or more matching blocks and one or more new matching blocks obtained by offsetting each of the one or more matching blocks, and establishing a temporal candidate mode list; determining the enhanced temporal motion vector prediction mode based on the index information; determining motion information of each sub-block in the current block based on the enhanced temporal motion vector prediction mode, and performing motion compensation on each sub-block in the current block.