Index: mplayer.c
===================================================================
--- mplayer.c	(revision 19473)
+++ mplayer.c	(working copy)
@@ -814,7 +814,7 @@
 #ifdef USE_ASS
     if (ass_enabled)
         asst = ass_read_file(filename);
-    if (ass_enabled && !asst)
+    if (ass_enabled && subd && !asst)
         asst = ass_read_subdata(subd, fps);
 
     if (!asst && !subd && !silent)