Multi-object Audio Encoding with Symmetric Downmix Parameter Scaling

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Solution Overview

Problem

Existing multi-object audio encoding and decoding technologies face challenges in efficiently encoding and decoding audio objects due to asymmetrically extracted downmix information parameters, leading to significant quantization errors and sound degradation when handling mastering downmix signals.

Innovation Solution

A multi-object audio encoding and decoding apparatus that supports post downmix signals by using a parameter determination unit to scale and adjust the post downmix signal to be symmetrically distributed with respect to 0 dB, reducing quantization errors and sound degradation through the use of a bitstream generation unit and downmix signal generation unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If asymmetric downmix information parameter extraction is used to support mastering downmix signals, then the system can handle arbitrary downmix signals, but significant quantization errors occur due to asymmetric distribution

Engineering Contradiction:

Improveability to handle mastering downmix signalsVSAvoidquantization accuracy of downmix information parameter

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by transforming the asymmetric downmix information parameter into a symmetric parameter through mathematical operations. Specifically, it uses the relationship between the encoder's downmix signal and the post downmix signal to derive a symmetric parameter that can be properly quantized using standard quantization tables, thereby resolving the quantization error issue while maintaining support for mastering downmix signals.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If existing CLD quantization tables are used for asymmetric parameters, then the encoding process is simple, but sound quality degrades due to significant quantization errors

Engineering Contradiction:

Improvesimplicity of encoding processVSAvoidsound quality of decoded audio

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces an intermediary transformation step that converts the asymmetric downmix information parameter into a symmetric parameter. This intermediary symmetric parameter serves as a bridge that allows the use of existing CLD quantization tables while accurately representing the relationship between downmix signals, thereby maintaining both encoding simplicity and sound quality.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11222645B2Multi-object audio encoding and decoding apparatus supporting post down-mix signal

Publication Date: 2022.01.11 ELECTRONICS & TELECOMM RES INST

AI summary

A multi-object audio encoding and decoding apparatus supporting a post downmix signal may be provided. The multi-object audio encoding apparatus may include: an object information extraction and downmix generation unit to generate object information and a downmix signal from input object signals; a parameter determination unit to determine a downmix information parameter using the extracted downmix signal and the post downmix signal; and a bitstream generation unit to combine the object information and the downmix information parameter, and to generate an object bitstream.