Multi-Channel Downmix Level Parameter for Stable Audio Reconstruction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multi-channel audio coding techniques face challenges in achieving high-quality reconstruction due to errors in inter-channel level differences and bit rate inefficiencies, particularly in error-prone transmission channels and varying energy levels, leading to artefacts and loudness fluctuations.
Innovation Solution
A parameterization concept that includes an additional level parameter to ensure energy equivalence between the downmix channel and original channels, allowing for flexible and scalable multi-channel reconstruction with reduced bit rate overhead, using balance parameters and decorrelation methods to adapt to different channel configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing multi-channel audio coding techniques are used, then encoding and decoding can be performed, but level variations and artefacts occur due to errors in inter-channel level differences and varying energy levels
Solution Approach 1:
The patent introduces a level parameter that dynamically adjusts the energy of the downmix channel to match the sum of energies of the original channels. This parameter change compensates for energy variations caused by inter-channel level difference errors, thereby reducing level variations and artefacts in the reconstructed multi-channel signal.
2Loss of information
If standard multi-channel coding is used, then channel reconstruction is possible, but bit rate efficiency is poor
Solution Approach 1:
The patent extracts only the essential energy information into a separate level parameter, rather than transmitting full multi-channel data. This extraction approach reduces bit rate overhead by representing the multi-channel signal through a downmix channel plus a compact level parameter, improving coding efficiency while preserving reconstruction quality.
3Adaptability or versatility
If inter-channel level differences are used for multi-channel reconstruction, then channel separation is achieved, but errors propagate in error-prone transmission channels
Solution Approach 1:
The patent introduces a level parameter as an intermediary that mediates between the downmix channel and the original multi-channel signal. This intermediary compensates for errors in inter-channel level differences by dynamically adjusting energy levels, thereby improving error robustness while maintaining channel configuration flexibility.
Data Source
AI summary
A parameter representation of a multi-channel signal having several original channels includes a parameter set, which, when used together with at least one down-mix channel allows a multi-channel reconstruction. An additional level parameter is calculated such that an energy of the at least one downmix channel weighted by the level parameter is equal to a sum of energies of the original channels. The additional level parameter is transmitted to a multi-channel reconstructor together with the parameter set or together with a down-mix channel. An apparatus for generating a multi-channel representation uses the level parameter to correct the energy of the at least one transmitted down-mix channel before entering the down-mix signal into an up-mixer or within the up-mixing process.