Complex Domain Audio Encoding for Stereo Channel Correlation
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Solution Overview
Problem
Current audio encoding methods for multi-channel signals fail to maximize the reduction in information between channels, leading to inefficiencies in encoding efficiency due to inadequate reflection of correlation between channels.
Innovation Solution
The method involves converting stereo channel signals from the real domain to the complex domain, determining operations such as sum, difference, or bypass based on power comparisons, and using complex spatial cues to encode and decode signals, thereby optimizing the encoding process by reflecting channel correlations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional audio encoding methods are used for multi-channel signals, then the encoding process is simple, but the reduction in information between channels is not maximized and encoding efficiency is insufficient
Solution Approach 1:
The patent transforms audio signals from the real domain to the complex domain by introducing an imaginary component through Hilbert transform. This dimensional extension allows the system to capture inter-channel correlations more effectively by representing signals as complex numbers with both real and imaginary parts, thereby maximizing information reduction between channels while improving encoding efficiency.
Solution Approach 2:
The patent changes the representation parameters of audio signals by converting them from real-valued signals to complex-valued signals. This parameter transformation enables the encoding system to exploit inter-channel correlations in the complex domain, leading to better encoding efficiency through more effective redundancy reduction between channels.
2Loss of information
If channel correlations are not adequately reflected in the encoding process, then the encoding process is straightforward, but the reduction in information between channels is not maximized
Solution Approach 1:
By extending the signal representation to the complex domain, the patent creates an additional dimension for analyzing and exploiting inter-channel correlations. The complex spatial cues derived from complex-valued signals provide more comprehensive information about channel relationships, enabling maximum information reduction while systematically handling the complexity of correlation reflection.
Data Source
AI summary
An encoding method and an encoding device using a complex signal and a decoding method and a decoding device using a complex signal are provided. The encoding method includes converting a first channel signal and a second channel signal constituting an audio signal corresponding to a stereo signal from a real domain to a complex domain, determining one of a sum operation, a difference operation, and a bypass operation to be performed on the second channel signal converted to the complex domain, determining a complex spatial cue according to the determined operation, converting a residual signal for the second channel signal to a real domain using the complex spatial cue, converting the first channel signal to a real domain, encoding the first channel signal converted to the real domain, and encoding the residual signal for the second channel signal converted to the real domain.