def convert_fourcc(fourcc_hex):
    """
    Convert a hexidecimal [fourcc](https://en.wikipedia.org/wiki/FourCC) 
    represpentation to a string.
    """
    s = []
    for i in range(0, 7, 2):
        n = int(fourcc_hex[i:i + 2], 16)
        if n is not 0:
            s.append(chr(n))
    return ''.join(s)
