diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 4c2f6ac960..2d75aaa76a 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -2773,7 +2773,7 @@ static inline void mc_dir_part(H264Context *h, Picture *pic, int n, int square,
     const int pic_width  = 16*s->mb_width;
     const int pic_height = 16*s->mb_height >> MB_MBAFF;
 
-    if(!pic->data[0])
+    if(!pic->data[0]) //FIXME this is unacceptable, some senseable error concealment must be done for missing reference frames
         return;
 
     if(mx&7) extra_width -= 3;