How to use the rdt.RealChallenge.AV_WB32 function in rdt

def compute(rc1):
        """ Translated from MPlayer's source
        Computes the realchallenge response and checksum """
        buf = list()
        buf.extend( RealChallenge.AV_WB32('a1e9149d') )
        buf.extend( RealChallenge.AV_WB32('0e6b3b59') )

        rc1 = rc1.strip()

        if rc1:
            if len(rc1) == 40: rc1 = rc1[:32]
            if len(rc1) > 56: rc1 = rc1[:56]
            buf.extend( [ ord(i) for i in rc1 ] )
            buf.extend( [ 0 for i in range(0, 56 - len(rc1)) ] )

        # xor challenge bytewise with xor_table
        for i in range(0, len(RealChallenge.XOR_TABLE)):
            buf[8 + i] ^= RealChallenge.XOR_TABLE[i];

        sum = md5( ''.join([ chr(i) for i in buf ]) )

        response = sum.hexdigest() + '01d0a8e3'

def compute(rc1):
        """ Translated from MPlayer's source
        Computes the realchallenge response and checksum """
        buf = list()
        buf.extend( RealChallenge.AV_WB32('a1e9149d') )
        buf.extend( RealChallenge.AV_WB32('0e6b3b59') )

        rc1 = rc1.strip()

        if rc1:
            if len(rc1) == 40: rc1 = rc1[:32]
            if len(rc1) > 56: rc1 = rc1[:56]
            buf.extend( [ ord(i) for i in rc1 ] )
            buf.extend( [ 0 for i in range(0, 56 - len(rc1)) ] )

        # xor challenge bytewise with xor_table
        for i in range(0, len(RealChallenge.XOR_TABLE)):
            buf[8 + i] ^= RealChallenge.XOR_TABLE[i];

        sum = md5( ''.join([ chr(i) for i in buf ]) )