Adaptive Entropy Model Switching for Low-Bitrate Audio Coding

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Solution Overview

Problem

Current audio compression techniques are inefficient in reducing bit rates while maintaining high quality, as they often require significant computational resources and memory, especially when dealing with multiple entropy models and VLC tables.

Innovation Solution

The use of selectively adaptive entropy models that switch between multiple models to optimize resource usage, clustering probability distributions, and constraining less probable symbol values to common conditional distributions, reduces memory and computational requirements while maintaining encoding gains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple entropy models and VLC tables are used to improve encoding efficiency, then bit rate reduction is improved, but memory usage and computational resources increase

Engineering Contradiction:
Improveencoding efficiencyVSAvoidmemory usage
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent segments the probability distributions into multiple clusters, where each cluster is represented by a codebook entry. This segmentation allows the system to use multiple entropy models selectively for different types of data patterns, improving encoding efficiency while managing memory usage through organized clustering

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic switching between different entropy models based on the characteristics of the input data. The system adaptsively selects which entropy model to use for encoding different symbol sequences, allowing optimal compression performance while avoiding the need to maintain all models simultaneously in memory

Inventive Principle:
Principle #15Dynamics

2Productivity

If multiple entropy models and VLC tables are used to improve encoding efficiency, then bit rate reduction is improved, but computational resources increase

Engineering Contradiction:
Improveencoding efficiencyVSAvoidcomputational resources
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The system dynamically selects entropy models based on data characteristics, using adaptive probability distribution clustering to determine which model to apply. This dynamic approach improves encoding efficiency by matching the right model to the right data pattern while avoiding the computational overhead of continuously processing through multiple models

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses partial action by applying entropy modeling selectively only when and where it provides benefit. The adaptive clustering approach identifies which symbol sequences benefit from entropy encoding and applies the appropriate model only to those cases, rather than uniformly applying multiple models to all data

Inventive Principle:
Principle #16Partial or excessive action

3Quantity of substance

If less probable symbol values are constrained to common conditional distributions, then memory usage is reduced, but encoding precision may be affected

Engineering Contradiction:
Improvememory usageVSAvoidencoding precision
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent applies different levels of probability distribution modeling to different symbol values. Less probable symbols are constrained to share common conditional distributions from codebook entries, while more probable symbols maintain their own specific distributions. This local differentiation reduces memory usage for rare symbols while preserving encoding precision for frequent symbols

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP1905000B1Selectively using multiple entropy models in adaptive coding and decoding
Publication Date: 2011.11.30 MICROSOFT CORP
  • EP1905000B1 patent drawingFigure 1
  • EP1905000B1 patent drawingFigure 2
  • EP1905000B1 patent drawingFigure 3

AI summary

Techniques and tools for selectively using multiple entropy models in adaptive coding and decoding are described herein. For example, for multiple symbols, an audio encoder selects an entropy model from a first model set that includes multiple entropy models. Each of the multiple entropy models includes a model switch point for switching to a second model set that includes one or more entropy models. The encoder processes the multiple symbols using the selected entropy model and outputs results. Techniques and tools for generating entropy models are also described.