kdllib.py 文件源码

def stft(X, fftsize=128, step="half", mean_normalize=True, real=False,
         compute_onesided=True):
    """
    Compute STFT for 1D real valued input X
    """
    if real:
        local_fft = fftpack.rfft
        cut = -1
    else:
        local_fft = fftpack.fft
        cut = None
    if compute_onesided:
        cut = fftsize // 2
    if mean_normalize:
        X -= X.mean()
    if step == "half":
        X = halfoverlap(X, fftsize)
    else:
        X = overlap(X, fftsize, step)
    size = fftsize
    win = 0.54 - .46 * np.cos(2 * np.pi * np.arange(size) / (size - 1))
    X = X * win[None]
    X = local_fft(X)[:, :cut]
    return X