kdllib.py 文件源码

def istft(X, fftsize=128, step="half", wsola=False, mean_normalize=True,
          real=False, compute_onesided=True):
    """
    Compute ISTFT for STFT transformed X
    """
    if real:
        local_ifft = fftpack.irfft
        X_pad = np.zeros((X.shape[0], X.shape[1] + 1)) + 0j
        X_pad[:, :-1] = X
        X = X_pad
    else:
        local_ifft = fftpack.ifft
    if compute_onesided:
        X_pad = np.zeros((X.shape[0], 2 * X.shape[1])) + 0j
        X_pad[:, :fftsize // 2] = X
        X_pad[:, fftsize // 2:] = 0
        X = X_pad
    X = local_ifft(X).astype("float64")
    if step == "half":
        X = invert_halfoverlap(X)
    else:
        X = overlap_add(X, step, wsola=wsola)
    if mean_normalize:
        X -= np.mean(X)
    return X