def p_track_start(t):
    """track_flag : START
                  | START TIMESTAMP"""
    from audiotools.toc import TOCFlag_START
    if len(t) == 2:
        t[0] = TOCFlag_START()
    else:
        from fractions import Fraction
        t[0] = TOCFlag_START(Fraction(t[2], 75))
