Index: libaf/af.c
===================================================================
RCS file: /cvsroot/mplayer/main/libaf/af.c,v
retrieving revision 1.44
retrieving revision 1.45
diff -u -r1.44 -r1.45
--- libaf/af.c	16 Apr 2005 16:48:15 -0000	1.44
+++ libaf/af.c	1 May 2005 09:23:31 -0000	1.45
@@ -368,6 +368,11 @@
   if(AF_OK != af_reinit(s,s->first))
     return -1;
 
+  // make sure the chain is not empty and valid (e.g. because of AF_DETACH)
+  if (!s->first)
+    if (!af_append(s,s->first,"dummy") || AF_OK != af_reinit(s,s->first))
+      return -1;
+
   // If force_output isn't set do not compensate for output format
   if(!force_output){
     memcpy(&s->output, s->last->data, sizeof(af_data_t));