Pre-emphasis filter, perception weighted filtering method and system

Abstract

The embodiment of the invention discloses a pre-emphasis filter, a perception weighted filtering method and a system; the pre-emphasis filter comprises a parameter determining module, a configuration module and a filtering module; the perception weighted filtering method comprises the following steps: the parameters of the pre-emphasis filter are determined according to low-frequency energy and high-frequency energy of an input signal; the pre-emphasis filter is arranged according to the parameters, the input signal is processed to obtain a first signal by the pre-emphasis filter; linear prediction LP analysis is carried out to the first signal, the coefficient of the perception weighted filter is determined; the perception weighted filter is arranged according to parameters and coefficients, and filtering is carried out to the first signal through the perception weighted filter; the perception weighted system mainly comprises the pre-emphasis filter, an LP filter, the configuration module and the perception weighted filter; by adopting the embodiment of the invention, the subjective hearing effect of voice coding is improved, and the invention is widely suitable for hybrid coding mode and can strictly control the complexity of the algorithm.

Description

technical field [0001] The present invention relates to the field of multimedia technology, in particular to a pre-emphasis filter, perceptual weighting filter method and system. Background technique [0002] The human ear's auditory sensitivity to a pure tone is affected by another pure tone that exists at the same time, but the human hearing can still clearly perceive the former pure tone. This phenomenon is called the masking effect of the human ear. [0003] When performing speech coding, the masking effect of the human ear can be used, that is, the noise at the formant is not easy to detect compared to the noise in the lower energy frequency band, and the formant valley can be reduced by allocating a larger distortion in the formant area. In this way, the subjective experience of more noise, thereby reducing the importance of the formant frequency region, improving the coding efficiency, and obtaining better subjective auditory effect, this speech coding technology is c...

AI Technical Summary

Problems solved by technology

[0006] This kind of filter can better simulate the formant structure of the speech spectrum in narrowband speech coding, but in wideband signals, due to the larger dynamic range between low frequency and high frequency, the slope of the signal spectrum is more obvious. Therefore, In the expanded adaptive multi-rate wideband speech coding technology, the high frequency and low frequency of the original speech signal are filtered by the pre-emphasis filter with preset parameters to reduce the dynamic range of the signal, but the subjective auditory effect of speech coding is poor.

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