2147483648c2 = F_UINT4.unpack(data[offset+17:offset+21])[0]-2147483648s2,s1 = struct.unpack('>BB',data[offset 2147483648c2 = F_UINT4.unpack(data[offset+17:offset+21])[0]-2147483648s2,s1 = struct.unpack('>BB',data[offset