Index: configure
===================================================================
--- configure	(Revision 23550)
+++ configure	(Arbeitskopie)
@@ -6997,7 +6997,9 @@
 if test "$_gui" = yes ; then
 
   # Required libraries
-  test "$_libavcodec" != yes && die "The GUI requires libavcodec with PNG support."
+  if test "$_libavcodec" != yes || test "`echo $_libavdecoders`" = "`echo $_libavdecoders | sed -e s/PNG_DECODER//`" ; then
+    die "The GUI requires libavcodec with PNG support."
+  fi
 if not win32 ; then
   test "$_x11" != yes && die "X11 support required for GUI compilation."