Audio Decoder Metadata Tuning for Wider Stereo Imaging

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Solution Overview

Problem

Existing audio widening methods are memory and processing power intensive due to the need for complex signal processing steps like Fourier transform and other transformations.

Innovation Solution

Amend audio parameters in the metadata of a compressed bitstream to enhance the perceived stereo image, using a computationally efficient method that modifies the bitstream before output by loudspeakers, eliminating the need for additional processing steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional audio widening methods (Fourier transform, signal processing) are used, then audio perception quality is improved, but memory and processing power consumption increase

Engineering Contradiction:
Improveaudio perception qualityVSAvoidprocessing power consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by modifying the audio parameters in the metadata before the audio signal is decoded and processed. By pre-adjusting parameters such as inter-channel level difference, inter-channel time difference, and spatial position in the compressed bitstream, the system achieves the desired audio widening effect without requiring complex signal processing operations during playback, thus reducing processing power consumption while maintaining audio perception quality

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts and modifies only the essential metadata parameters from the compressed audio bitstream rather than processing the entire audio signal. By taking out just the relevant spatial and stereo parameters from the metadata section and adjusting them, the system achieves audio widening with minimal computational overhead, avoiding the need for resource-intensive Fourier transforms and signal processing operations

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If traditional audio widening methods are used, then audio perception quality is improved, but device complexity increases

Engineering Contradiction:
Improveaudio perception qualityVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and modifies only the essential metadata parameters from the compressed audio bitstream rather than processing the entire audio signal. By taking out just the relevant spatial and stereo parameters from the metadata section and adjusting them, the system achieves audio widening with minimal computational overhead, avoiding the need for resource-intensive Fourier transforms and signal processing operations

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent works with a simplified representation (copy) of the audio signal in the form of metadata parameters rather than the full audio signal. By copying and modifying only the essential spatial and stereo parameters from the compressed bitstream metadata, the system achieves the desired audio widening effect without requiring complex processing of the complete audio signal, thus reducing device complexity

Inventive Principle:
Principle #26Copying

Data Source

PatentEP4672230A1Audio widening utilizing metadata
Publication Date: 2025.12.31 HARMAN BECKER AUTOMOTIVE SYST GMBH
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AI summary

The application relates to a method carried out at an audio decoder, wherein a bitstream of compressed audio data including metadata is received by the audio decoder. In the metadata, at least one audio parameter is determined which influences a perception of an audio signal which is generated based on the bitstream and played out by a plurality of loudspeakers. The at least one audio parameter is amended in order to generate an amended bitstream, wherein an amended audio signal generated based on the amended bitstream leads to an amended perception compared to perception when the audio signal is played out by the loudspeakers based on the unamended bitstream. Furthermore, the amended bitstream is decoded for playback by the plurality of loudspeakers