SAMPLING RATE CONVERSION DEVICE AND METHOD, AND AUDIO DEVICE

摘要

There is provided a sampling rate conversion device capable of obtaining an amplitude characteristic passing through an arbitrary frequency and realizing a highly-accurate conversion not depending on the cut-off frequency. The sampling rate conversion device includes: an up-sampler (103) for inserting (U - 1) zero points between signals and increasing the sampling frequency Fsi by U; a convolution calculation unit (104) having a FIR filter for interpolating a value by convolution for the output signal of the up- sampler; and a linear interpolation block (105) for selecting samples at two points from the output signal of the convolution calculation unit (104) of the sampling frequency UFsi and calculating the value of the necessary position from the linear interpolation. The FIR filter has a filter coefficient which is an impulse response. A transmission function H(z) is correlated to a transmission function Z(z) of the pre-filter. The filter coefficient is correlated to the frequency response of the pre- filter and set by performing weighted approximation for a desired characteristic.