Audio Encoding Channel Combination Scheme for Energy Balance
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Solution Overview
Problem
Conventional time-domain stereo encoding technologies often result in low energy levels of primary signals, degrading encoding quality due to the inability to effectively manage energy differences between left and right channel signals.
Innovation Solution
The method involves determining a channel combination scheme and encoding mode for each frame based on the downmix mode of the previous frame and the current frame, using anticorrelated and correlated signal channel combination schemes to perform time-domain downmix processing and encoding, which includes segmented processing to maintain energy balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional time-domain stereo encoding technology is used, then encoding delay is reduced, but primary signal energy becomes very small or absent, degrading encoding quality
Solution Approach 1:
The patent applies dynamics by making the downmixing parameters adaptive rather than fixed. The channel combination scheme and downmixing factors are dynamically adjusted based on the correlation characteristics of the left and right channel signals. This allows the encoding system to optimize the energy distribution between primary and secondary channels according to the actual signal conditions, resolving the contradiction between maintaining low encoding delay and ensuring sufficient primary signal energy for quality encoding.
Solution Approach 2:
The patent changes the parameters of the downmixing process by introducing different channel combination schemes (fully correlated, partially correlated, fully anticorrelated) and adjusting the downmixing factors based on signal correlation. This parameter adaptation ensures that the primary channel maintains adequate energy across different stereo signal conditions while still operating in the time domain to avoid encoding delay, thus resolving the technical contradiction.
2Device complexity
If conventional time-domain stereo encoding technology is used, then processing complexity is reduced, but energy balance between channels deteriorates, leading to poor encoding quality
Solution Approach 1:
The patent introduces dynamic adaptation in the time-domain encoding process by calculating correlation metrics and selecting appropriate channel combination schemes based on signal characteristics. This dynamic approach improves energy balance between channels without significantly increasing processing complexity, as the additional calculations are limited to correlation assessment and scheme selection rather than full spectral analysis.
Solution Approach 2:
The patent changes the downmixing parameters adaptively by selecting from different channel combination schemes and adjusting downmixing factors based on measured signal correlation. This parameter adaptation resolves the energy balance issue while maintaining relatively simple time-domain processing, avoiding the need for complex frequency-domain transformations or iterative optimization algorithms.
3Device complexity
If fixed downmixing is used, then encoding process is simplified, but energy distribution between primary and secondary channels becomes unbalanced
Solution Approach 1:
The patent makes the downmixing process dynamic by adapting the channel combination scheme and downmixing factors to the actual signal correlation characteristics. This dynamic adjustment ensures proper energy distribution between primary and secondary channels based on whether the signals are correlated or anticorrelated, resolving the energy balance problem while keeping the encoding process relatively simple through rule-based adaptation rather than complex optimization.
Solution Approach 2:
The patent changes the downmixing parameters by selecting from different channel combination schemes (fully correlated, partially correlated, fully anticorrelated) based on signal characteristics. This parameter adaptation resolves the energy distribution issue by matching the downmixing strategy to the actual signal relationship, avoiding both overly complex processing and fixed inadequate approaches.
Data Source
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AI summary
An audio encoding and decoding method and a product are provided. The method includes: determining a channel combination scheme for a current frame (201); determining an encoding mode of the current frame based on a downmix mode of a previous frame and the channel combination scheme for the current frame (202); and performing time-domain downmix processing on left and right channel signals of the current frame based on the encoding mode of the current frame, to obtain primary and secondary channel signals of the current frame, and encoding the obtained primary and secondary channel signals of the current frame (203). This method helps improve encoding quality.