Multichannel Audio Predictive Decoding with Parameter Recovery

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Solution Overview

Problem

Predictive coding schemes in multichannel audio are sensitive to errors, leading to error propagation and inefficient bandwidth usage, especially in unstable audio scenes.

Innovation Solution

A method and apparatus that replace decoded parameters with estimated parameters in a decoder based on the last observed active source, using a parameter stability measure to determine when to activate parameter recovery, reducing bandwidth waste and preventing audio freezing during unstable scenes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If predictive coding schemes are used in multichannel audio, then bandwidth efficiency is improved, but error propagation occurs and reliability deteriorates

Engineering Contradiction:

Improvebandwidth consumptionVSAvoiderror propagation

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The system performs preliminary actions by estimating parameters in advance and storing them before errors occur. When packet loss is detected, these pre-computed estimated parameters are immediately substituted to prevent error propagation, eliminating the need for reactive error correction and maintaining bandwidth efficiency.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system creates copies of parameter data by maintaining both decoded parameters and estimated parameters. When errors occur in the transmitted decoded parameters, the system uses the copied estimated parameters as substitutes, ensuring continuous operation without requiring additional transmission bandwidth for error correction data.

Inventive Principle:

Principle #26Copying

2Reliability

If parameter recovery is activated during unstable audio scenes, then error propagation is mitigated, but bandwidth is wasted during error-free channels

Engineering Contradiction:

Improveerror propagation mitigationVSAvoidbandwidth waste

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The system dynamically adjusts its operation mode based on real-time conditions. It monitors packet loss indicators and audio scene stability, activating parameter recovery only when errors are detected or instability is observed. During stable error-free periods, the system operates in normal decoded-parameter mode, automatically adapting to minimize bandwidth consumption while maintaining reliability when needed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system implements feedback mechanisms by continuously monitoring packet loss indicators and audio scene stability. This feedback controls when parameter recovery is activated, ensuring that the computationally intensive parameter estimation and substitution processes are only performed when actually needed, thereby avoiding unnecessary bandwidth waste during error-free operation.

Inventive Principle:

Principle #23Feedback

3Loss of energy

If decoded parameters are used during unstable audio scenes, then bandwidth consumption is reduced, but audio quality deteriorates due to error propagation

Engineering Contradiction:

Improvebandwidth consumptionVSAvoidaudio quality

Core Design Contradiction:

Loss of energyVSManufacturing precision

Solution Approach 1:

The system creates and maintains copies of parameter data in the form of estimated parameters that are computed independently of the transmitted bitstream. When audio scene instability or packet loss is detected, these copied estimated parameters are substituted for the decoded parameters, preserving audio quality without requiring additional bandwidth for error correction.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The system changes the parameter representation by switching between using decoded parameters from the bitstream and using estimated parameters computed from historical data. This parameter substitution mechanism allows the system to maintain audio quality during unstable scenes by replacing corrupted or inaccurate decoded parameters with reliable estimated parameters, without permanently increasing bandwidth requirements.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20260051329A1Method and apparatus for error recovery in predictive coding in multichannel audio frames

Publication Date: 2026.02.19 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method, apparatus and decoder for replacing decoded parameters in a received multichannel signal in which a frame of consecutive frames of the received multichannel signal is decoded and responsive to receiving a previous frame bad frame indicator while operating in a predictive decoding mode with a current frame of the consecutive frames, it is determined whether a parameter stability measure is below a threshold. Responsive to the parameter stability measure being below the threshold a parameter recovery is activated by retrieving the estimated parameters and replacing decoded parameters of the current frame with the estimated parameters. Otherwise, it is detected whether a source is an active source and responsive to the source being an active source, decoded parameters of the current frame are stored as estimated parameters and the parameter stability measure is determined.