Reference Picture Resampling Flags for Spatially Scalable Decoding

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Solution Overview

Problem

Existing video coding technologies struggle with efficiently managing changes in picture size and resolution within a coded video sequence, particularly in modern codecs like VVC, which require improved signaling and resampling mechanisms for reference pictures to handle diverse scene activities and resolutions.

Innovation Solution

The proposed method involves decoding an encoded video bitstream by obtaining flags indicating whether reference picture resampling is enabled and whether picture resolution is changed, and adapting the decoding process accordingly using reference picture resampling for spatial scalability and adaptive resolution change (ARC) when necessary, or without it when not changed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If reference picture resampling is enabled for spatial scalability and adaptive resolution change, then the flexibility and adaptability of video decoding is improved, but the device complexity and computational complexity increase

Engineering Contradiction:

Improveflexibility of video decodingVSAvoidcomputational complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic resolution changes within a coded video sequence by enabling reference picture resampling. The system can adaptively adjust the resolution of reference pictures based on scene activity and coding requirements, transitioning between different resolution levels dynamically rather than being fixed, thus improving flexibility while managing complexity through controlled adaptability

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the resolution parameter of reference pictures through resampling operations. By modifying the resolution parameter dynamically based on coding conditions and scene characteristics, the system achieves adaptive resolution change that balances flexibility with computational requirements, allowing the decoder to adjust picture size without requiring complete reconfiguration

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If picture resolution is changed within a coded video sequence, then the adaptability to diverse scene activities is improved, but the signaling complexity increases

Engineering Contradiction:

Improveadaptability to scene activitiesVSAvoidsignaling complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the video sequence into coded video sequences with specific resolution characteristics. By dividing the video into manageable segments that can have different resolution settings, the system achieves adaptability to diverse scene activities while controlling signaling complexity through structured segmentation rather than continuous variation

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary resampling of reference pictures before they are needed for coding. By preparing reference pictures at appropriate resolutions in advance based on predicted scene requirements, the system reduces the need for complex real-time signaling and resolution changes, thereby improving adaptability while managing signaling overhead

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If reference pictures are resampled for different resolutions, then the spatial scalability is improved, but the loss of information increases

Engineering Contradiction:

Improvespatial scalabilityVSAvoidinformation loss during resampling

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent discards high-resolution reference pictures when downsampling is required and recovers the necessary information through controlled resampling operations. By selectively discarding redundant high-resolution data and recovering only the essential information needed for the target resolution, the system achieves spatial scalability while minimizing information loss through intelligent data management

Inventive Principle:

Principle #34Discarding and recovering

Solution Approach 2:

The patent creates scaled copies of reference pictures at different resolutions through resampling. Instead of modifying the original high-resolution reference picture, the system creates appropriate-resolution copies for different coding scenarios, preserving the original high-quality reference while enabling spatial scalability through multiple copies at different resolutions

Inventive Principle:

Principle #26Copying

Data Source

PatentEP3939264B1Techniques for signaling combination of reference picture resampling and spatial scalability

Publication Date: 2025.11.19 TENCENT AMERICA LLC

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AI summary

A method, device, and non-transitory computer-readable medium for decoding an encoded video bitstream using at least one processor, including, obtaining from the encoded video bitstream a first flag indicating that reference picture resampling is enabled for coded video sequence (CVS); determining a value of a second flag indicating whether a picture resolution is changed in the CVS; based on the value of the second flag indicating that the picture resolution is changed in the CVS, decoding the CVS using the reference picture resampling for spatial scalability and adaptive resolution change (ARC); and based on the value of the second flag indicating that the picture resolution is not changed in the CVS, decoding the CVS using the reference picture resampling for the spatial scalability, and without using the reference picture resampling for the ARC.