return inf correctly from audioarray.compare if signals are equal

    if get_mld:

        result["MLD"] = 0

    if get_ssnr:

        result["SSNR"] = np.zeros(ref.shape[1])

        result["SSNR"] = np.asarray([np.inf] * ref.shape[1])

    if per_frame:

        result["max_abs_diff_pos_frame"] = 0