--- a
+++ b/m4/linnsongcast.m4
@@ -0,0 +1,8 @@
+AC_DEFUN([AC_FUNC_LIBUPNPP_LINNSONGCAST],[
+AC_SINGLE_CXX_CHECK([ac_cv_func_setsourceindex_in_linn],
+                    [setSourceIndex], [<libupnpp/control/linnsongcast.hxx>],
+                    [const std::string s; int i=0; UPnPClient::Songcast::setSourceIndex(s,i);])
+if test "$ac_cv_func_setsourceindex_in_linn" = "yes" ; then
+  AC_DEFINE([HAVE_SETSOURCEINDEX_IN_LINN],1,[Set to 1 if the setSourceIndex function is found in libupnpp])
+fi
+])