Parametric Audio Stream Mixing Without Decode-Reencode Delay

Solution Overview

Problem

Existing audio coding techniques lack the ability to efficiently combine multiple parametrically coded audio streams without requiring decoding and re-encoding, leading to high computational complexity and delay, which is unsuitable for real-time applications like teleconferencing.

Innovation Solution

An audio signal generator that combines parametrically coded audio streams by directly mixing down-mix channels and associated parameters within the parameter domain, using simple arithmetic operations such as summation and weight calculations, without reconstructing the individual audio signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple parametrically coded audio streams are combined by decoding and re-encoding, then audio quality is preserved, but computational complexity and processing delay increase significantly

Engineering Contradiction:

Improveaudio qualityVSAvoidcomputational complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts only the necessary parametric information (spatial parameters, power ratios, and down-mix signals) from the encoded audio streams, rather than fully decoding the complete audio signals. This selective extraction allows combination operations to be performed on compact parameter representations, significantly reducing computational complexity while maintaining audio quality.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention transforms the combination operation from signal-domain processing to parameter-domain processing. By operating directly on the parametric representations (power ratios, spatial parameters, and down-mix signals) rather than full audio waveforms, the system achieves efficient combination with minimal computational effort and processing delay.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If multiple parametrically coded audio streams are combined by decoding and re-encoding, then audio quality is preserved, but processing delay increases

Engineering Contradiction:

Improveaudio qualityVSAvoidprocessing delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The invention extracts only the necessary parametric information (spatial parameters, power ratios, and down-mix signals) from the encoded audio streams, rather than fully decoding the complete audio signals. This selective extraction allows combination operations to be performed on compact parameter representations, significantly reducing computational complexity while maintaining audio quality.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention transforms the combination operation from signal-domain processing to parameter-domain processing. By operating directly on the parametric representations (power ratios, spatial parameters, and down-mix signals) rather than full audio waveforms, the system achieves efficient combination with minimal computational effort and processing delay.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If multiple parametrically coded audio streams are combined directly in parameter domain, then computational effort and delay are reduced, but audio quality may be compromised

Engineering Contradiction:

Improveprocessing efficiencyVSAvoidaudio quality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The invention uses the down-mix signal as an intermediary carrier that preserves the essential audio information in a compressed form. By combining down-mix signals along with their associated parametric information, the system maintains audio quality while operating in the parameter domain, as the down-mix serves as a faithful representation that can be properly reconstructed.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention transforms the combination operation from signal-domain processing to parameter-domain processing. By operating directly on the parametric representations (power ratios, spatial parameters, and down-mix signals) rather than full audio waveforms, the system achieves efficient combination with minimal computational effort and processing delay.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUSRE50818E1Concept for combining multiple parametrically coded audio sources

Publication Date: 2026.03.10 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV

AI summary

According to the present invention, multiple parametrically encoded audio signals can be efficiently combined using an audio signal generator, which generates an audio output signal by combining the down-mix channels and the associated parameters of the audio signals directly within the parameter domain, i.e. without reconstructing or decoding the individual input audio signals prior to the generation of the audio output signal. This is achieved by direct mixing of the associated down-mix channels of the individual input signals. It is one key feature of the present invention that the combination of the down-mix channels is achieved by simple, computationally inexpensive arithmetic operations.