Stereo Phase Parameter Encoding via Sub-band ITD Smoothing
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Solution Overview
Problem
Current methods for recovering stereo phase information from stereo audio signals using global parameters result in low accuracy, leading to poor stereo audio phase information effects.
Innovation Solution
A method and apparatus that acquire and adjust global stereo phase parameters, specifically the group delay (G_ITD) and group phase (G_IPD), by calculating and smoothing inter-channel time differences across sub-bands, allowing for improved accuracy in encoding stereo phase information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If global parameters (G_ITD, G_IPD) are extracted directly from stereo audio signals, then the encoding process is simple, but the accuracy of stereo phase information recovery is low
Solution Approach 1:
The patent divides the frequency spectrum into multiple sub-bands and calculates inter-channel time differences for each sub-band separately. This segmentation allows for more precise local measurements while the overall process remains systematic and manageable, resolving the contradiction between measurement precision and process complexity
Solution Approach 2:
The patent performs preliminary smoothing processing on inter-channel time differences before using them to adjust global parameters. This preliminary action improves the quality of input data for parameter recovery, enhancing accuracy without significantly increasing the overall encoding complexity
2Measurement precision
If inter-channel time differences are calculated and smoothed across sub-bands, then the accuracy of global stereo phase parameters is improved, but the encoding complexity increases
Solution Approach 1:
The patent applies different processing strategies to different sub-bands based on their local characteristics. By calculating and smoothing ITD values locally in each sub-band and then combining them, the system achieves high accuracy while keeping each local processing step relatively simple and modular
Solution Approach 2:
The patent uses the calculated and smoothed inter-channel time differences as feedback to adjust the global stereo phase parameters. This feedback mechanism ensures that the global parameters accurately reflect the local sub-band characteristics, improving overall accuracy while maintaining a clear cause-effect relationship that simplifies the adjustment process
Data Source
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AI summary
Embodiments of the present invention disclose a method and an apparatus for encoding a stereo phase parameter, which relate to the field of information technologies and can improve an effect of stereo audio phase information. The method includes: first, acquiring a global stereo phase parameter of a current frame; then, determining a value of the global stereo phase parameter of the current frame, and adjusting the value of the global stereo phase parameter of the current frame according to a determining result of the value of the global stereo phase parameter of the current frame; and finally, encoding an adjusted value of the global stereo phase parameter of the current frame. The embodiments of the present invention are applicable to recovering stereo phase information.