def frontiers_from_time_to_frame_idx(seq, hop_length_seconds):
    """
    Converts a sequence of frontiers in time to their values in frame indexes.

    Parameters
    ----------
    seq : list of float/times
        The list of times to convert.
    hop_length_seconds : float
        hop_length (time between two consecutive frames), in seconds.

    Returns
    -------
    list of integers
        The sequence, as a list, in frame indexes.
    """
    
    return [int(round(frontier/hop_length_seconds)) for frontier in seq]