Audio Object Clustering Using Spatial Error Metrics

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Solution Overview

Problem

Existing audio signal processing technologies face challenges in determining spatial error metrics and audio quality degradation during audio object clustering, leading to inefficiencies in format conversion, rendering, and transmission, particularly in reducing the number of audio objects while maintaining spatial fidelity.

Innovation Solution

The development of a method and system that computes spatial error metrics and audio quality degradation by analyzing intra-frame and inter-frame spatial errors, using importance-weighted and normalized error metrics, and predicting subjective audio quality through correlation with user surveys, to optimize the audio object clustering process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of audio objects is reduced through clustering, then bandwidth and processing requirements are decreased, but spatial fidelity and audio quality may deteriorate

Engineering Contradiction:
Improveencoding efficiencyVSAvoidspatial fidelity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent implements feedback by computing spatial error metrics (such as azimuth angle error, elevation angle error, and distance error) between original audio objects and clustered audio objects. These error metrics are used to evaluate and optimize the clustering process, ensuring that spatial fidelity is maintained while achieving compression goals. The feedback loop allows iterative refinement of clustering parameters to balance efficiency and quality.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent employs parameter changes by adjusting clustering thresholds, error metric weights, and spatial tolerance levels to optimize the balance between compression ratio and spatial fidelity. Different parameter sets can be applied depending on the specific application requirements, allowing flexible control over the trade-off between encoding efficiency and audio quality.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If spatial error metrics are computed for all audio objects, then audio quality assessment is improved, but processing time and computational complexity increase

Engineering Contradiction:
Improveaudio quality assessmentVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies local quality by computing spatial error metrics selectively for audio objects that meet specific criteria (such as those with significant spatial characteristics or those that are likely to impact perceived audio quality). This selective approach focuses computational resources on critical audio objects while reducing overall processing time for less important objects.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements partial action by computing a subset of spatial error metrics (such as only azimuth angle error or only elevation angle error) depending on the specific application needs, rather than computing all possible metrics. This partial computation approach reduces processing time while still providing sufficient quality assessment for the given application.

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If audio content is adapted for multiple distribution settings, then versatility and adaptability are improved, but device complexity and processing requirements increase

Engineering Contradiction:
Improvedistribution setting adaptabilityVSAvoidprocessing system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements universality by creating a unified audio object-based representation that can be adapted to multiple distribution settings (such as immersive audio, stereo, mono, different channel configurations) through a single source. The spatial error metric computation framework serves multiple functions by evaluating quality across different rendering scenarios and providing optimization guidance for various distribution formats simultaneously.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3092642B1Spatial error metrics of audio content
Publication Date: 2018.05.16 DOLBY LABORATORIES LICENSING CORP
  • EP3092642B1 patent drawingFigure 1~2
  • EP3092642B1 patent drawingFigure 3A
  • EP3092642B1 patent drawingFigure 3B

AI summary

Audio objects that are present in input audio content in one or more frames are determined. Output clusters that are present in output audio content in the one or more frames are also determined. Here, the audio objects in the input audio content are converted to the output clusters in the output audio content. One or more spatial error metrics are computed based at least in part on positional metadata of the audio objects and positional metadata of the output clusters.