def tc2s(tc:str, base:float=25) -> float:
    """Convert an SMPTE timecode (HH:MM:SS:FF) to number of seconds

    Args:
        tc (str):
            Source timecode

        base (float):
            Frame rate (default: 25)

    Returns:
        float:
            Resulting value in seconds
    """
    tc = tc.replace(";", ":")
    hh, mm, ss, ff = [int(e) for e in tc.split(":")]
    res = hh * 3600
    res += mm * 60
    res += ss
    res += ff / float(base)
    return res