Multichannel Audio Coding with Transient Extraction for Clean Upmix
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multichannel audio encoding and decoding technologies introduce distortion, artefacts, and inefficiencies, particularly in the recreation of transient properties, leading to degraded audio quality and higher data rates and computational complexity.
Innovation Solution
An audio apparatus that extracts single-channel transient components, combines them into mono transient components, and generates downmix audio data with upmix parameters to improve the reconstruction of multichannel audio signals, reducing data rate and computational load while maintaining high audio quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional parametric multichannel coding is used to downmix multichannel audio signals, then data rate is reduced, but audio quality is degraded and transient properties are distorted
Solution Approach 1:
The audio signal is segmented into transient components and non-transient components separately. Transient components are identified through transient detection in each channel and extracted as distinct signal portions. This segmentation allows different processing strategies to be applied to different signal types, preserving transient characteristics while achieving efficient coding of the remaining signal.
Solution Approach 2:
Transient components are extracted from the multichannel audio signal before downmixing. By removing and separately encoding transient portions, the patent avoids the distortion and artifacts that would otherwise be introduced by traditional parametric coding methods during the downmixing process.
2Quantity of substance
If traditional parametric multichannel coding is used to downmix multichannel audio signals, then data rate is reduced, but distortion and artefacts are introduced
Solution Approach 1:
Transient components are extracted from the multichannel audio signal before downmixing. By removing and separately encoding transient portions, the patent avoids the distortion and artifacts that would otherwise be introduced by traditional parametric coding methods during the downmixing process.
Solution Approach 2:
Transient detection and extraction are performed as preliminary steps before the downmixing operation. This preliminary action identifies and isolates transient components that would be vulnerable to distortion during subsequent processing, allowing them to be protected from harmful effects.
3Quantity of substance
If multichannel audio signals are downmixed to reduce data rate, then data rate is reduced, but computational complexity increases
Solution Approach 1:
Instead of applying complex parametric coding to the entire multichannel signal, the patent applies transient detection and extraction only to specific signal portions where transients are present. This partial action reduces computational complexity compared to full-signal processing while maintaining coding efficiency benefits.
4Quantity of substance
If traditional downmixing is applied to multichannel audio, then data rate is reduced, but transient properties are lost
Solution Approach 1:
Transient components are extracted from the multichannel audio signal before downmixing. By removing and separately encoding transient portions, the patent avoids the distortion and artifacts that would otherwise be introduced by traditional parametric coding methods during the downmixing process.
Solution Approach 2:
Transient detection and extraction are performed as preliminary steps before the downmixing operation. This preliminary action identifies and isolates transient components that would be vulnerable to distortion during subsequent processing, allowing them to be protected from harmful effects.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An encoder comprises a transient extractor (103) generating a residual multichannel audio signal by extracting single channel transient signal components. A combiner circuit (105) generates a set of mono transient signal components by combining single channel transient signal components. A downmix circuit (107) generates downmix audio data by downmixing the residual multichannel audio signal and the mono channel transient signal components, and generates signal upmix parameters for upmixing the residual multichannel audio signal and transient upmix parameters for upmixing the mono channel transient signal components. An output circuit (109) generates an encoded audio data signal comprising the generated data. A decoder has upmixers that upmix the received downmixed residual signal and the mono transient signal components using the received parameters, including generating a plurality of transient signal components for one received mono transient signal component.