libraw1394 handle
pointer to an array of struct raw1394_portinfo
number of elements in pinf
Before you can set which port to use, you have to use this function to find out which ports exist.
If your program is interactive, you should present the user with this list to let them decide which port to use if there is more than one. A non-interactive program (and probably interactive ones, too) should provide a command line option to choose the port. If maxports is 0, pinf can be NULL, too.