Bandwidth Switching in Speech Signal Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sudden switching between different bandwidths in speech/audio signals causes aural discomfort and energy changes due to abrupt changes in bandwidth, leading to deterioration in audio quality during transmission.
Innovation Solution
A method that corrects high-frequency signals during bandwidth switching by using a predicted global gain parameter, ensuring that the bandwidth switching algorithm and coding/decoding algorithm operate within the same signal domain to maintain signal continuity and quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If bandwidth switching is performed between wide and narrow frequency bands, then transmission efficiency is improved, but aural discomfort occurs due to sudden signal bandwidth changes
Solution Approach 1:
The patent applies preliminary action by predicting the high-frequency signal before bandwidth switching occurs. The prediction uses linear predictive coding to generate an estimated high-frequency signal in advance, which is then used during the switching process to ensure smooth transition and avoid aural discomfort while maintaining transmission efficiency
2Quantity of substance
If bandwidth switching is performed between wide and narrow frequency bands, then resource occupation is reduced, but abrupt energy changes occur causing deterioration of aural quality
Solution Approach 1:
The patent uses an energy ratio as an intermediary parameter to control the bandwidth switching process. By calculating the energy ratio between the predicted high-frequency signal and the narrowband signal, and using this ratio to adjust the switching transition, the system reduces resource occupation while preventing abrupt energy changes that would deteriorate aural quality
3Adaptability or versatility
If bandwidth switching is performed, then adaptability to different network statuses is improved, but filter state updating errors occur causing signal discontinuity
Solution Approach 1:
The patent applies feedback by using the predicted high-frequency signal to update filter states during bandwidth switching. The prediction mechanism provides feedback information that allows the system to adjust filter states smoothly, maintaining signal continuity while adapting to different network statuses through controlled bandwidth switching
Data Source
Figure 2
Figure 3
Figure 4~5
AI summary
Embodiments of the present invention disclose a speech/audio signal processing method and apparatus. In an embodiment, the speech/audio signal processing method includes: when a speech/audio signal switches bandwidth, obtaining an initial high frequency signal corresponding to a current frame of speech/audio signal; obtaining a time-domain global gain parameter of the initial high frequency signal; performing weighting processing on an energy ratio and the time-domain global gain parameter, and using an obtained weighted value as a predicted global gain parameter, where the energy ratio is a ratio between energy of a historical frame of high frequency time-domain signal and energy of a current frame of initial high frequency signal; correcting the initial high frequency signal by using the predicted global gain parameter, to obtain a corrected high frequency time-domain signal; and synthesizing a current frame of narrow frequency time-domain signal and the corrected high frequency time-domain signal and outputting the synthesized signal.