def get_vbr_frame_size(mpeg_size, frame_count):
    """Get VBR average frame size.
    
    :param mpeg_size: Size of MPEG in bytes.
    :type mpeg_size: int
    
    :param frame_count: Count of frames in MPEG.
    :type frame_count: int
    
    :return: Average frame size.
    :rtype: number
    
    """
    return mpeg_size / frame_count