Multi-Hypothesis Entropy Coding With Time-Variant Model Updates

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing entropy coding techniques for digital video streams face challenges in accurately updating probability models, leading to inefficiencies in data compression and processing.

Innovation Solution

The proposed solution involves regularizing probability models for entropy coding by using time-variant update rates for multi-hypothesis probability models, ensuring accurate probability estimation and efficient coding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single probability model is used for entropy coding, then the device complexity is reduced, but the measurement precision of probability estimation deteriorates

Engineering Contradiction:
Improveprobability estimation accuracyVSAvoidprobability model complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the single probability model into multiple separate probability models (first probability model and second probability model), each tracking different hypotheses about symbol probabilities. This segmentation allows more accurate probability estimation by maintaining multiple competing hypotheses simultaneously, resolving the contradiction between accuracy and complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces time-variant update rates that change parameters dynamically - using higher update rates initially when less data is available, and lowering update rates as more data accumulates. This parameter change allows the system to adapt to data availability and improve probability estimation accuracy without proportionally increasing complexity.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If a fixed update rate is used for the probability model, then the ease of operation is improved, but the adaptability to varying data conditions deteriorates

Engineering Contradiction:
Improveadaptation rate flexibilityVSAvoidmodel update complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent implements dynamic update rates that automatically adjust based on the amount of data processed. The update rate is higher when fewer symbols have been coded and lowers as more symbols are processed, allowing the system to adapt to varying data conditions without manual intervention, thus improving adaptability while maintaining ease of operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from the coding process itself - specifically the count of symbols coded through current observation - to automatically adjust the update rate. This feedback mechanism enables the probability model to adapt its behavior based on actual data conditions, improving versatility without complicating operation.

Inventive Principle:
Principle #23Feedback

3Productivity

If multiple probability models are maintained with different update rates, then the productivity of entropy coding is improved, but the device complexity increases

Engineering Contradiction:
Improveentropy coding efficiencyVSAvoidmulti-hypothesis model complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the probability modeling into multiple parallel models with different update rates, allowing the system to explore multiple hypotheses simultaneously. This segmentation improves entropy coding productivity by selecting the most accurate model for current data conditions, while the modular structure manages complexity through clear separation of concerns.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the coding process use different update rates - higher rates early in the process when data is scarce, and lower rates later when data is abundant. This local quality approach optimizes coding efficiency at each stage without uniformly increasing complexity across the entire system.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS20250159176A1Time-Variant Multi-Hypothesis Probability Model Update for Entropy Coding
Publication Date: 2025.05.15 GOOGLE LLC
  • US20250159176A1 patent drawing
  • US20250159176A1 patent drawing
  • US20250159176A1 patent drawing

AI summary

Entropy coding a sequence of syntax elements using a time-variant multi-hypothesis probability model update is described. A sequence of syntax elements is received, and a symbol for a syntax element of the sequence is determined. The symbol is coded by arithmetic coding using a linear combination of a first probability model and a second probability model. The first probability model is updated using a first time-variant update rate to produce a first updated probability model for entropy coding a symbol for a subsequent syntax element of the sequence, and the second probability model is updated using a second time-variant update rate to produce a second updated probability model for entropy coding the symbol for the subsequent syntax element of the sequence. The first and second time-variant update rates are different.