Audio Parameter Interpolation for Spatial Audio Coding

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Solution Overview

Problem

Existing audio source coding systems face challenges in achieving high-quality spatial audio reconstruction while minimizing data transmission, particularly in optimizing the trade-off between time and frequency resolution of spatial parameters and efficiently signaling these parameters.

Innovation Solution

The solution involves a decoder and encoder system that uses adaptive interpolation characteristics to generate high-resolution parametric information from low-resolution data, with features like estimation and signaling of interpolation curves, implicit interpolation rules, and recalculating parameters to the upmix matrix domain for efficient interpolation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If low-resolution parametric information is transmitted to reduce data overhead, then data transmission efficiency is improved, but spatial audio reconstruction quality deteriorates

Engineering Contradiction:
Improvedata overheadVSAvoidspatial audio reconstruction quality
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The encoder pre-calculates and transmits auxiliary information (interpolation curves, characteristic values, or high-resolution parameter sets) that enables the decoder to reconstruct high-resolution parametric information from low-resolution transmitted data. This preliminary preparation of reconstruction data allows quality recovery without increasing transmitted data volume.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Interpolation curves and characteristic values act as intermediaries between the transmitted low-resolution parameters and the reconstructed high-resolution parameters. These intermediary elements carry the essential information needed to bridge the resolution gap, enabling accurate spatial audio reconstruction from compressed data.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If high-resolution parametric information is transmitted to improve spatial audio reconstruction quality, then spatial audio reconstruction quality is improved, but data overhead increases

Engineering Contradiction:
Improvespatial audio reconstruction qualityVSAvoiddata overhead
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The system extracts only the most essential and informative parameters for transmission at low resolution, while deriving the remaining high-resolution parameters through interpolation and reconstruction algorithms. This selective extraction minimizes transmitted data while preserving reconstruction quality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system changes the resolution parameter of transmitted data to low-resolution, while using interpolation curves and characteristic values to restore high-resolution parameters at the decoder. This parameter transformation allows quality preservation without proportionate increase in data transmission.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If frequent parameter updates are performed to improve time resolution, then time resolution is improved, but coding efficiency deteriorates

Engineering Contradiction:
Improvetime resolutionVSAvoidcoding efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system updates parameters periodically at lower frequencies, using interpolation curves to generate high-resolution parameter values between update points. This periodic updating with interpolation maintains perceived time resolution while reducing actual parameter transmission frequency, thereby improving coding efficiency.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

Interpolation curves are pre-calculated and stored, allowing the system to generate high-resolution parameter values without real-time computation. This preliminary preparation enables efficient decoding with high time resolution without requiring frequent parameter transmissions.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS7974847B2Advanced methods for interpolation and parameter signalling
Publication Date: 2011.07.05 DOLBY INTERNATIONAL AB
  • US7974847B2 patent drawing
  • US7974847B2 patent drawing
  • US7974847B2 patent drawing

AI summary

A parameter calculator calculates lower resolution parametric information and interpolation information. On a decoder-side, an upmixer is used for generating the output channels. The upmixer uses high resolution parametric information generated by a parameter interpolator using the low resolution parametric information and decoder-side derived interpolation information or encoder-generated interpolation information for selecting one of a plurality of different interpolation characteristics.