Binaural Multi-Channel Decoding With HRTF Energy Correction
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Solution Overview
Problem
Existing methods for generating binaural signals from multi-channel audio face challenges in energy conservation and spectral coloring due to non-energy-conserving upmixing rules, particularly when using HRTF filters, leading to artifacts in binaural decoding.
Innovation Solution
A multi-channel decoder is developed that calculates a gain factor to correct energy errors in the upmixing process, using upmix rule information and HRTF filter characteristics to produce an energy-corrected binaural signal without fully rendering the multi-channel signal, thereby reducing 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 losses while preserving waveform matching quality, thereby resolving the contradiction between waveform accuracy and energy conservation.
2Productivity
If HRTF filters are combined linearly based on prediction parameters, then computational efficiency is improved, but spectral coloring artifacts increase
Solution Approach 1:
The patent converts the harmful spectral coloring artifacts into beneficial effects by using energy correction factors that deliberately adjust the frequency response. The system takes the energy errors generated by linear HRTF combination and transforms them into corrective measures that eliminate spectral coloring while maintaining computational efficiency.
3Manufacturing precision
If full multi-channel rendering is performed before binaural decoding, then audio quality is improved, but computational complexity increases
Solution Approach 1:
The patent performs preliminary energy correction calculations using prediction parameters before the actual binaural decoding process. By pre-computing energy correction factors based on available downmix signals and prediction data, the system prepares corrected HRTF filters in advance, thereby maintaining audio quality while reducing the computational complexity of the main decoding process.
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.