Binaural Multi-Channel Decoding With HRTF Energy Correction
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Solution Overview
Problem
Existing methods for binaural decoding of multi-channel audio signals using HRTF filtering face challenges in energy conservation and spectral coloring due to non-energy-conserving upmixing rules, especially when downmixing signals with spatial parameters lead to energy errors and artifacts.
Innovation Solution
A multi-channel decoder is developed that calculates a gain factor to reduce or eliminate energy errors by using upmix rule information and HRTF filter characteristics, allowing for energy-corrected binaural signal generation without fully rendering the multi-channel signal, and applies this gain factor during filtering to mitigate spectral coloring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If non-energy-conserving upmixing rules are used to achieve waveform matching, then waveform matching quality is improved, but energy conservation deteriorates causing energy errors
Solution Approach 1:
The patent changes the parameters of the upmixing process by introducing energy correction factors that adjust the energy distribution of upmixed channels. The system modifies the upmixing parameters dynamically to compensate for energy loss while preserving waveform matching quality, thereby resolving the contradiction between waveform accuracy and energy conservation.
2Measurement precision
If HRTF filtering is applied to downmix signals with spatial parameters, then binaural decoding quality is improved, but spectral coloring artifacts increase due to energy errors
Solution Approach 1:
The patent applies preliminary energy correction to the downmix signals before HRTF filtering is applied. By pre-compensating for the energy errors that would otherwise cause spectral coloring artifacts, the system prevents these harmful effects from occurring during the binaural decoding process, thus maintaining high decoding quality without artifacts.
3Measurement precision
If full multi-channel signal rendering is performed before binaural decoding, then decoding accuracy is improved, but computational complexity increases
Solution Approach 1:
The patent extracts and corrects only the essential energy parameters from the full multi-channel signal before applying HRTF filtering for binaural decoding. This selective extraction approach maintains decoding accuracy by preserving critical energy information while avoiding the computational burden of processing the complete multi-channel signal, thus reducing overall computational complexity.
Data Source
AI summary
A multi-channel decoder for generating a binaural signal from a downmix signal using upmix rule information on an energy-error introducing upmix rule for calculating a gain factor based on the upmix rule information and characteristics of head related transfer function based filters corresponding to upmix channels. The one or more gain factors are used by a filter processor for filtering the downmix signal so that an energy corrected binaural signal having a left binaural channel and a right binaural channel is obtained.