快速傅氏变换（FFT），允许用户查看的音频信号的频谱内容。 FFT这里给出的代码是由唐交叉出现，他的主页，随后被撤下。而不是解释的FFT的数学理论，我将试图解释它的用处，因为它涉及到的音频信号。



FFT允许用户获得的音频信号的频谱构成，获得它的各种频率的分贝，或获得其各种频率的强度。光谱观众（在上面的图片所示），均衡器，或VU表可以使用FFT，以显示其结果。它们之间的差值，然后取决于一对夫妇方程采取的FFT的实部和虚部的组件，并返回的强度或分贝水平被用于在绘制结果中的一个。下面的代码提取的FFT结果的实部和虚数部分，并返回的强度和分贝。-The Fast Fourier Transform (FFT), to allow the user to view the audio signal spectral content. FFT code given here by Don cross, his home, and subsequently removed. The FFT math theory rather than to explain, I will attempt to explain its usefulness, as it relates to the audio signal. FFT allows the frequency spectrum of the audio signal obtained by the user, and to obtain various frequency in decibels, or the intensity of various frequencies. The spectrum of the audience (in the above picture shown), equalizer or VU meter can use the FFT, to display its results. The difference between them, and then depending on the one pair of couples equations take the FFT of the real part and the imaginary part component, and returns the intensity or decibel levels be used in one of the plotted results. The following code extract a real part and an imaginary part of the results of the FFT, and return the strength and decibels.