Video Coding with Affine Motion Compensation and Selective Buffering

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Solution Overview

Problem

Video data requires significant storage space for buffering intermediate data during encoding and decoding, especially with high-resolution and high-frame-rate video coding techniques, and existing affine motion prediction methods do not efficiently manage buffer resources.

Innovation Solution

A method and apparatus for video encoding and decoding that reduce temporal buffer requirements by selectively storing and retrieving motion vectors for affine candidate derivation, using a temporal buffer to store fewer motion vectors than conventional systems, and deriving affine candidates based on retrieved motion vectors from neighboring blocks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional affine motion prediction methods are used, then coding performance is maintained, but buffer storage space increases significantly

Engineering Contradiction:
Improvecoding performanceVSAvoidbuffer storage space
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent extracts only the essential motion vectors needed for affine candidate derivation from the temporal buffer, storing fewer motion vectors than conventional systems. Specifically, it retrieves motion vectors selectively based on block position and affine mode requirements, rather than buffering all motion vectors, thereby reducing buffer storage space while maintaining coding performance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the buffer management into different regions based on block position (e.g., top blocks, left blocks, center blocks) and retrieves motion vectors selectively from appropriate segments. This segmentation allows the system to store fewer motion vectors overall while still providing the necessary candidates for affine prediction, resolving the contradiction between buffer size and coding performance.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If more motion vectors are stored in temporal buffer, then affine candidate derivation accuracy improves, but device complexity and memory requirements increase

Engineering Contradiction:
Improveaffine candidate derivation accuracyVSAvoidmemory requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies partial action by retrieving only the necessary number of motion vectors (e.g., 1-3 motion vectors) needed for affine candidate derivation rather than storing all possible motion vectors. This partial retrieval strategy maintains sufficient accuracy for affine prediction while significantly reducing memory requirements and device complexity.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent implements local quality by adapting the number and type of motion vectors retrieved based on the specific block position and affine mode being used. Different blocks receive different numbers of motion vector candidates (e.g., top blocks get vectors from above, left blocks get vectors from left), optimizing accuracy for each local region while reducing overall buffer requirements.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3414900B1Method and apparatus of video coding with affine motion compensation
Publication Date: 2025.08.06 HFI INNOVATION INC
  • EP3414900B1 patent drawingFigure 1A~1B
  • EP3414900B1 patent drawingFigure 2~3
  • EP3414900B1 patent drawingFigure 4A~4B

AI summary

A method and apparatus for video encoding and decoding with affine motion compensation are disclosed. An embodiment of the method receives input data associated with a current block coded or to be coded in an affine mode. Two or more motion vectors of a neighboring block are retrieved from a buffer, where at least one of the retrieved motion vectors is not corresponding to a sub-block in a first neighboring block row or a first neighboring block column. The method derives an affine candidate including affine motion vectors using the retrieved two or more motion vectors, and encodes or decodes the current block by predicting the current block using one or more motion compensated blocks by the derived affine candidate. The buffer for affine candidate derivation stores selective motion vectors less than all motion vectors of coded blocks in the current picture.