Lost Frame Recovery Using Low-Band Gain Adjustment
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Solution Overview
Problem
Existing methods for recovering lost frames in voice signal transmission using bandwidth extension technologies often result in discontinuous transitions between recovered and adjacent frames due to inconsistent energy variation trends between high and low frequency bands, leading to noise in the voice signal.
Innovation Solution
Adjusting the high-band signal of a lost frame based on the low-band signal to ensure consistent interframe variation trends between high and low frequency bands, thereby improving the performance of lost frame recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If bandwidth extension technology is used to encode voice signal with wider bandwidth at unchanged bit rate, then voice signal bandwidth is improved, but discontinuous transition occurs between recovered lost frame and adjacent frames causing noise
Solution Approach 1:
The patent adjusts the gain parameter of the high-band signal in the lost frame by scaling it with a factor derived from the low-band signal's gain variation. This parameter adjustment ensures that the high-band signal's energy transition matches the low-band signal's transition pattern, eliminating discontinuities and noise while preserving the bandwidth extension benefit
Solution Approach 2:
The patent uses the low-band signal's gain variation as feedback to adjust the high-band signal's gain. By comparing the low-band gain before and after the lost frame and applying this variation to the high-band signal, the system creates a closed-loop adjustment that ensures consistent energy transition across frame boundaries
Data Source
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AI summary
Embodiments of the present invention provide a method and an apparatus for processing a lost frame, where the method for processing a lost frame includes: determining an initial high-band signal of a current lost frame; determining a gain of the current lost frame; determining gain adjustment information of the current lost frame, where the gain adjustment information includes at least one of the following: a class of a frame, a low-band signal spectral tilt of a frame, a low-band signal energy of a frame, and a quantity of consecutive lost frames, where the quantity of consecutive lost frames is a quantity of consecutive frames that are lost until the current lost frame; adjusting the gain of the current lost frame according to the gain adjustment information, to obtain an adjusted gain of the current lost frame; and adjusting the initial high-band signal according to the adjusted gain, to obtain a high-band signal of the current lost frame. The method and the apparatus for processing a lost frame provided in the embodiments of the present invention are used to improve performance in recovery of a lost frame of an audio signal.