自己写的利用FFT变换实现的声音频谱分析函数，支持多声道wav，可以对FFT变换点数、时间分辨率、频率分辨率、显示方式进行定制-Wrote it myself using FFT transform the voice spectrum analysis function, support multi-channel wav, can transform FFT points, time resolution, frequency resolution, and display customiz