Audio Bitstream Multiplexing for Efficient High-Frequency Coding

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Solution Overview

Problem

The challenge of improving encoding and decoding efficiency for audio signals, particularly in frequency domain processing, to effectively transmit audio signals over limited bandwidths.

Innovation Solution

An audio encoding method that involves obtaining encoding parameters for high and low frequency bands, including tone component and sub-band envelope information, and performing bitstream multiplexing to reduce redundancy, and a decoding method that performs bitstream demultiplexing and frequency band extension to reconstruct audio signals efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional audio encoding methods are used to transmit audio signals over limited bandwidth, then the audio signal can be transmitted, but the encoding and decoding efficiency is insufficient

Engineering Contradiction:
Improveencoding and decoding efficiencyVSAvoidinformation redundancy
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent segments the audio signal into different frequency bands (low frequency band and high frequency band) and processes each band separately with dedicated encoding parameters. The high frequency band is further divided into sub-bands for envelope coding. This segmentation allows targeted processing that reduces overall redundancy while maintaining encoding efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different encoding strategies to different frequency regions based on their characteristics. Tone components in the high frequency band are encoded with specific tone parameters, while non-tone regions use sub-band envelope information. This local quality approach ensures that each region is encoded with the most efficient method for its specific characteristics, reducing information redundancy.

Inventive Principle:
Principle #3Local quality

2Reliability

If encoding parameters include both tone component information and sub-band envelope information, then encoding completeness is improved, but bit consumption increases

Engineering Contradiction:
Improveencoding completenessVSAvoidbit consumption
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent encodes only the necessary portions of the audio signal with high precision. Tone components are encoded with specific tone parameters when present, while non-tone regions use sub-band envelope information. This partial action approach encodes only what is needed for each region, avoiding excessive bit consumption while maintaining encoding completeness.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent dynamically changes encoding parameters based on the signal characteristics. When tone components are detected in the high frequency band, tone parameters are used; otherwise, sub-band envelope parameters are used. This parameter change strategy adapts the encoding method to the actual signal content, reducing bit consumption while maintaining completeness.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4080504B1Method and device for encoding and decoding audio
Publication Date: 2025.06.25 HUAWEI TECH CO LTD
  • EP4080504B1 patent drawingFigure 1~2
  • EP4080504B1 patent drawingFigure 3
  • EP4080504B1 patent drawingFigure 4~6

AI summary

Embodiments of this application disclose an audio coding method, including: obtaining a current frame of an audio signal, where the current frame includes a high frequency band signal and a low frequency band signal; obtaining a first encoding parameter of the current frame based on the high frequency band signal and the low frequency band signal; obtaining a second encoding parameter of the current frame based on the high frequency band signal, where the second encoding parameter includes tone component information of the high frequency band signal; obtaining a third encoding parameter of the current frame based on the high frequency band signal, where the third encoding parameter includes sub-band envelope information of a part of sub-band of the high frequency band signal that needs to be encoded; and performing bitstream multiplexing on the first encoding parameter, the second encoding parameter, and the third encoding parameter, to obtain an encoded bitstream. The method can improve encoding efficiency.