audio_tools.py 文件源码

def sinusoid_analysis(X, input_sample_rate, resample_block=128, copy=True):
    """
    Contruct a sinusoidal model for the input signal.

    Parameters
    ----------
    X : ndarray
        Input signal to model

    input_sample_rate : int
        The sample rate of the input signal

    resample_block : int, optional (default=128)
       Controls the step size of the sinusoidal model

    Returns
    -------
    frequencies_hz : ndarray
       Frequencies for the sinusoids, in Hz.

    magnitudes : ndarray
       Magnitudes of sinusoids returned in ``frequencies``

    References
    ----------
    D. P. W. Ellis (2004), "Sinewave Speech Analysis/Synthesis in Matlab",
    Web resource, available: http://www.ee.columbia.edu/ln/labrosa/matlab/sws/
    """
    X = np.array(X, copy=copy)
    resample_to = 8000
    if input_sample_rate != resample_to:
        if input_sample_rate % resample_to != 0:
            raise ValueError("Input sample rate must be a multiple of 8k!")
        # Should be able to use resample... ?
        # resampled_count = round(len(X) * resample_to / input_sample_rate)
        # X = sg.resample(X, resampled_count, window=sg.hanning(len(X)))
        X = sg.decimate(X, input_sample_rate // resample_to, zero_phase=True)
    step_size = 2 * round(resample_block / input_sample_rate * resample_to / 2.)
    a, g, e = lpc_analysis(X, order=8, window_step=step_size,
                           window_size=2 * step_size)
    f, m = lpc_to_frequency(a, g)
    f_hz = f * resample_to / (2 * np.pi)
    return f_hz, m