I cannot build libxine. The problems seem to be in Makefile. First:
PATCH_DEPENDS= libtool15:${PORTSDIR}/devel/libtool15
libtool15 creates a program called libtool, not libtool15.
Second:
${CP} ${LTMAIN} ${WRKSRC}/ltmain.sh
I don't see that LTMAIN is defined anywhere.
Best Stephen