--- common/frame.c.old	2010-02-06 13:35:09 +0900
+++ common/frame.c	2010-02-06 13:37:00 +0900
@@ -75,6 +75,7 @@
     frame->b_fdec = b_fdec;
 
     frame->i_pic_struct = PIC_STRUCT_AUTO;
+    frame->b_top_field_first = h->param.b_tff;
     frame->i_field_cnt = -1;
 
     frame->orig = frame;