audio_tools.py 文件源码

def harvest_get_downsampled_signal(x, fs, target_fs):
    decimation_ratio = np.round(fs / target_fs)
    offset = np.ceil(140. / decimation_ratio) * decimation_ratio
    start_pad = x[0] * np.ones(int(offset), dtype=np.float32)
    end_pad = x[-1] * np.ones(int(offset), dtype=np.float32)
    x = np.concatenate((start_pad, x, end_pad), axis=0)

    if fs < target_fs:
        raise ValueError("CASE NOT HANDLED IN harvest_get_downsampled_signal")
    else:
        try:
            y0 = sg.decimate(x, int(decimation_ratio), 3, zero_phase=True)
        except:
            y0 = sg.decimate(x, int(decimation_ratio), 3)
        actual_fs = fs / decimation_ratio
        y = y0[int(offset / decimation_ratio):-int(offset / decimation_ratio)]
    y = y - np.mean(y)
    return y, actual_fs