Audio Frame Error Concealment with Previous-Frame Adaptive Modes
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Solution Overview
Problem
Existing audio signal encoding and decoding methods using time-frequency transform processing face challenges in concealing frame errors without additional time delay or excessive complexity, leading to deteriorated sound quality due to frame errors.
Innovation Solution
An apparatus and method for frame error concealment that utilizes signal characteristics in the time domain to smooth rapid signal fluctuations caused by error frames with low complexity and without additional delay, accurately reconstructing transient or burst error frames, and minimizing the impact on adjacent frames.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frame error concealment is performed using only autocorrelation method or only moment method, then the decoding complexity is reduced, but the audio quality deteriorates when frames are lost or corrupted
Solution Approach 1:
The patent dynamically selects between autocorrelation method and moment method based on the error status of previous frames. When previous frames are error-free, autocorrelation is used; when errors are detected, moment method is used. This dynamic adaptation resolves the contradiction by adjusting the concealment strategy according to real-time conditions, maintaining audio quality without requiring complex simultaneous implementation of both methods.
Solution Approach 2:
The patent changes the concealment parameter (method selection) based on the error status of previous frames. By monitoring whether previous frames contained errors and adjusting the concealment approach accordingly, the system optimizes audio quality for different error conditions while maintaining manageable decoding complexity through conditional logic rather than comprehensive complex processing.
2Reliability
If multiple error concealment methods are simultaneously implemented, then the audio quality is improved, but the processing time and computational load increase
Solution Approach 1:
The patent segments the error concealment process into distinct modes (autocorrelation mode and moment method mode) that are selectively applied based on error conditions. Instead of simultaneously implementing multiple methods, the system divides the processing into separate conditional paths, reducing processing time while maintaining audio quality through appropriate method selection for each error scenario.
Solution Approach 2:
The patent applies partial action by selecting only the necessary concealment method based on current error conditions rather than applying all possible methods. When previous frames are error-free, only autocorrelation is applied; when errors are present, only moment method is applied. This partial application resolves the contradiction by avoiding unnecessary computational overhead while maintaining sufficient audio quality.
3Reliability
If error concealment is performed without considering previous frame status, then the processing is simplified, but the concealment effectiveness deteriorates
Solution Approach 1:
The patent implements feedback by monitoring the error status of previous frames and using this information to guide the selection of concealment methods for current frames. This feedback mechanism improves concealment effectiveness by adapting to actual error conditions while maintaining reasonable processing complexity through simple conditional checks on previous frame status rather than complex analysis.
Solution Approach 2:
The patent performs preliminary action by detecting and recording the error status of previous frames before selecting the concealment method for current frames. This preliminary error status assessment enables more effective concealment decisions while keeping processing complexity manageable through simple state tracking rather than complex real-time analysis during the concealment process itself.
Data Source
Figure 1A~1B
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Figure 2B
AI summary
Disclosed is a frame error concealment (FEC) method. The method includes: selecting an FEC mode based on states of a current frame and a previous frame of the current frame in a time domain signal generated after time-frequency inverse transform processing; and performing corresponding time domain error concealment processing on the current frame based on the selected FEC mode, wherein the current frame is an error frame or the current frame is a normal frame when the previous frame is an error frame.