TFMethods.py 文件源码

def iDFT(magX, phsX, wsz):
        """ Discrete Fourier Transformation(Synthesis) of a given spectral analysis
        via an inverse FFT implementation from scipy.
        Args:
            magX    : (2D ndarray) Magnitude Spectrum
            phsX    : (2D ndarray) Phase Spectrum
            wsz     :  (int)   Synthesis window size
        Returns:
            y       : (array) Real time domain output signal
        """

        # Get FFT Size
        hlfN = magX.size;
        N = (hlfN-1)*2

        # Half of window size parameters
        hw1 = int(math.floor((wsz+1)/2))
        hw2 = int(math.floor(wsz/2))

        # Initialise synthesis buffer with zeros
        fftbuffer = np.zeros(N)
        # Initialise output spectrum with zeros
        Y = np.zeros(N, dtype = complex)
        # Initialise output array with zeros
        y = np.zeros(wsz)

        # Compute complex spectrum(both sides) in two steps
        Y[0:hlfN] = magX * np.exp(1j*phsX)
        Y[hlfN:] = magX[-2:0:-1] * np.exp(-1j*phsX[-2:0:-1])

        # Perform the iDFT
        fftbuffer = np.real(ifft(Y))

        # Roll-back the zero-phase windowing technique
        y[:hw2] = fftbuffer[-hw2:]
        y[hw2:] = fftbuffer[:hw1]

        return y