Video Decoder Scaling List Prediction Validation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing video encoding and decoding technologies face challenges in efficiently signaling scaling lists, particularly in scenarios where chroma components are not present, leading to potential decoder crashes or improper decoding due to invalid reference scaling lists.

Innovation Solution

The proposed solution involves modifying the value range of scaling_list_pred_id_delta and updating the derivation of reference scaling list IDs to ensure that the reference scaling list always points to a valid scaling list. Additionally, default values can be used to determine new scaling matrices when invalid references occur.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If scaling list prediction is implemented without validating reference list existence, then decoding efficiency is improved, but decoder reliability deteriorates causing crashes

Engineering Contradiction:
Improvedecoding efficiencyVSAvoiddecoder reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by validating the existence of reference scaling lists before using them for prediction. The decoder checks whether a reference scaling list with the predicted ID actually exists in the current component before attempting to use it, preventing invalid memory access and decoder crashes while maintaining efficient prediction when references are valid

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent introduces an intermediary validation step between the reference scaling list identification and the actual prediction operation. This intermediary check acts as a mediator that ensures the reference list exists and is valid before allowing the prediction to proceed, bridging the gap between efficient prediction and reliable operation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of substance

If chroma components are excluded from scaling list signaling, then bitrate is reduced, but scaling list validity deteriorates causing invalid references

Engineering Contradiction:
ImprovebitrateVSAvoidscaling list validity
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The patent introduces an intermediary validation mechanism that checks component-specific scaling list existence before cross-component prediction. When predicting luma scaling lists, the system validates whether the chroma reference list actually exists in the current picture configuration, preventing invalid references while maintaining bitrate efficiency through selective prediction

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent dynamically changes the behavior of scaling list prediction based on picture parameters (chroma presence). The validation logic adapts to different picture configurations, enabling prediction when chroma exists and preventing invalid references when chroma is absent, thus maintaining both bitrate efficiency and scaling list validity across different scenarios

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4115616B1Scaling list signalling for video coding
Publication Date: 2025.05.28 QUALCOMM INC
  • EP4115616B1 patent drawingFigure 1
  • EP4115616B1 patent drawingFigure 2A~2B
  • EP4115616B1 patent drawingFigure 3

AI summary

A video decoder can be configured to determine that a new scaling list for a set of scaling lists is to be predicted from a reference scaling list, wherein the new scaling list corresponds to a new scaling matrix; receive a syntax element that identifies an ID number corresponding to a scaling list of the set of scaling lists that is to be used as the reference scaling list; determine that the set of scaling lists does not include a scaling list with the ID number; and in response to determining that the set of scaling lists does not include the scaling list with the ID number, determine the new scaling matrix based on a set of default values.