diff -up gpac/Makefile.libdir gpac/Makefile
--- gpac/Makefile.libdir	2007-08-28 14:51:16.000000000 +0200
+++ gpac/Makefile	2008-02-17 14:47:22.000000000 +0100
@@ -63,11 +63,11 @@ ifeq ($(DEBUGBUILD),no)
 	$(STRIP) bin/gcc/libgpac.$(DYN_LIB_SUFFIX)
 endif
 ifeq ($(CONFIG_DARWIN),yes)
-	install -m 755 bin/gcc/libgpac.$(DYN_LIB_SUFFIX) $(DESTDIR)$(prefix)/lib/libgpac-$(VERSION).$(DYN_LIB_SUFFIX)
-	ln -sf libgpac-$(VERSION).$(DYN_LIB_SUFFIX) $(DESTDIR)$(prefix)/lib/libgpac.$(DYN_LIB_SUFFIX)
+	install -m 755 bin/gcc/libgpac.$(DYN_LIB_SUFFIX) $(DESTDIR)$(libdir)/libgpac-$(VERSION).$(DYN_LIB_SUFFIX)
+	ln -sf libgpac-$(VERSION).$(DYN_LIB_SUFFIX) $(DESTDIR)$(libdir)/libgpac.$(DYN_LIB_SUFFIX)
 else
-	install $(INSTFLAGS) -m 755 bin/gcc/libgpac.$(DYN_LIB_SUFFIX) $(DESTDIR)$(prefix)/lib/libgpac-$(VERSION).$(DYN_LIB_SUFFIX)
-	ln -sf libgpac-$(VERSION).$(DYN_LIB_SUFFIX) $(DESTDIR)$(prefix)/lib/libgpac.$(DYN_LIB_SUFFIX)
+	install $(INSTFLAGS) -m 755 bin/gcc/libgpac.$(DYN_LIB_SUFFIX) $(DESTDIR)$(libdir)/libgpac-$(VERSION).$(DYN_LIB_SUFFIX)
+	ln -sf libgpac-$(VERSION).$(DYN_LIB_SUFFIX) $(DESTDIR)$(libdir)/libgpac.$(DYN_LIB_SUFFIX)
 	ldconfig || true
 endif
 endif
@@ -98,7 +98,7 @@ install-lib:
 	mkdir -p "$(DESTDIR)$(prefix)/include/gpac/modules"
 	install -m 644 $(SRC_PATH)/include/gpac/modules/*.h "$(DESTDIR)$(prefix)/include/gpac/modules"
 	mkdir -p "$(DESTDIR)$(prefix)/lib"
-	install -m 644 "./bin/gcc/libgpac_static.a" "$(DESTDIR)$(prefix)/lib"
+	install -m 644 "./bin/gcc/libgpac_static.a" "$(DESTDIR)$(libdir)"
 
 uninstall-lib:
 	rm -rf "$(prefix)/include/gpac/internal"
diff -up gpac/configure.libdir gpac/configure
--- gpac/configure.libdir	2007-10-25 11:39:51.000000000 +0200
+++ gpac/configure	2008-02-17 14:53:30.000000000 +0100
@@ -106,6 +106,7 @@ EOF
 echo "GPAC configuration options:"
 echo "  --help                   print this message"
 echo "  --prefix=PREFIX          install in PREFIX [$prefix]"
+echo "  --libdir=LIBDIR          system libs in DIR [$libdir]"
 echo "  --mandir=DIR             man documentation in DIR [PREFIX/man]"
 echo ""
 echo "  --source-path=PATH       path of source code [$source_path]"
@@ -167,6 +168,8 @@ for opt do
   case "$opt" in
   --prefix=*) prefix=`echo $opt | cut -d '=' -f 2`
   ;;
+  --libdir=*) libdir=`echo $opt | cut -d '=' -f 2`
+  ;;
   --mandir=*) mandir=`echo $opt | cut -d '=' -f 2`
   ;;
   --source-path=*) source_path=`echo $opt | cut -d '=' -f 2`
@@ -479,7 +482,7 @@ fi
 
 if $cc -o $TMPO $TMPC $LINK3D 2> /dev/null  ; then
 has_opengl="yes"
-elif $cc -o $TMPO $TMPC -I$X11_PATH/include -L$X11_PATH/lib 2> /dev/null  ; then
+elif $cc -o $TMPO $TMPC -I$X11_PATH/include -L$X11_PATH/lib -L${libdir} 2> /dev/null  ; then
 has_opengl="yes"
 fi
 
@@ -895,7 +898,7 @@ cat > $TMPC << EOF
 #include <X11/Xlib.h>
 int main( void ) { return 0; }
 EOF
-if $cc -o $TMPO $TMPC -I$X11_PATH/include -L$X11_PATH/lib 2> /dev/null  ; then
+if $cc -o $TMPO $TMPC -I$X11_PATH/include -L$X11_PATH/lib -L${libdir} 2> /dev/null  ; then
 has_x11="yes"
 
 #look for X11 shared memory support
@@ -1173,8 +1176,9 @@ fi
 fi
 
 echo "prefix=$prefix" >> config.mak
+echo "libdir=$libdir" >> config.mak
 echo "DESTDIR=$DESTDIR" >> config.mak
-echo "moddir=$prefix/lib/gpac" >> config.mak
+echo "moddir=$libdir/gpac" >> config.mak
 echo "mandir=$mandir" >> config.mak
 echo "MAKE=$make" >> config.mak
 echo "CC=$cc" >> config.mak