feature_extractor.py 文件源码

def ams_extractor(x, sr, win_len, shift_len, order=1, decimate_coef=1./4.):
    from scipy.signal import hilbert
    envelope = np.abs(hilbert(x))
    for i in range(order-1):
        envelope = np.abs(hilbert(envelope))
    envelope = envelope * decimate_coef
    frames = (len(envelope) - win_len) // shift_len
    hanning_window = np.hanning(win_len)
    ams_feature = np.zeros(shape=(15, frames))
    wts = cal_triangle_window(0, sr//2, win_len, 15, 15.6, 400)
    for i in range(frames):
        one_frame = x[i*shift_len:i*shift_len+win_len]
        one_frame = one_frame * hanning_window
        frame_fft = np.abs(np.fft.fft(one_frame, win_len))
        ams_feature[:,i] = np.matmul(wts, frame_fft)
    return ams_feature