=== modified file 'configure.ac'
--- configure.ac	2010-06-11 09:29:19 +0000
+++ configure.ac	2010-06-11 09:32:09 +0000
@@ -82,11 +82,7 @@
 LDFLAGS="$LDFLAGS -rdynamic "
 
 dnl define path of plugins:
-theprefix=$prefix
-if test "$prefix" = "NONE"; then
-	theprefix="/usr/local"
-fi
-PACKAGE_PLUGINS_DIR=`eval echo $theprefix/lib/mediastreamer/plugins`
+PACKAGE_PLUGINS_DIR=`$PKG_CONFIG --variable=msplugindir mediastreamer` 
 AC_DEFINE_UNQUOTED(PACKAGE_PLUGINS_DIR,  "$PACKAGE_PLUGINS_DIR" ,[path of plugins])
 AC_SUBST(PACKAGE_PLUGINS_DIR)