Method and device for recovering high-frequency signal

Abstract

The present application provides a method and device for restoring a high-frequency signal, belonging to the technical field of audio. The method includes: the terminal can acquire the audio signal sampled by a preset number of sampling points, the high-frequency signal in the audio signal is copied to the low-frequency signal in the audio signal, and then the sampled audio signal can be separated according to the preset frequency. , obtain the target high-frequency signal and the target low-frequency signal, perform double oversampling processing on the target high-frequency signal, and perform double oversampling processing on the target low-frequency signal. The target low-frequency signal after double oversampling processing is superimposed and synthesized, and the audio signal after superposition and synthesis is subjected to linear half-band low-pass filtering processing. In the audio signal after the linear half-band low-pass filtering processing, half Sampling processing to obtain an audio signal whose high-frequency signal is phase-recovered. By adopting the present application, the accuracy of the recovered high-frequency signal can be improved.

Description

technical field [0001] The present application relates to the field of audio technology, in particular to a method and device for restoring high-frequency signals. Background technique [0002] In the audio field, in order to save audio data transmission resources, the audio data is generally low-pass filtered to filter out high-frequency signals that are not sensitive to the human auditory system, and then the low-pass filtered audio data is compressed to improve compression. rate to reduce the data volume of audio data. With the development of computer technology, the improvement of audio digital-to-analog converters and earphone sound quality, when the audio data is played, the defects caused by the filtered high-frequency signal are becoming more and more obvious, so it is urgent to provide a high-recovery frequency signal method. [0003] In the related art, the filter bank value of the low frequency band is generated from the MDCT (modified discrete cosine transform)...

AI Technical Summary

Problems solved by technology

[0004] Since the low-band filterbank values ​​are only copied to the high-band filterbank values, the high-band filterbank values ​​are in the same phase as the low-band filterbank values, resulting in recovered high-frequency The phase of the signal is exactly the same as that of the original low-frequency signal, and the recovered high-frequency signal cannot be accurate

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