diff --git a/libavcodec/h264_refs.c b/libavcodec/h264_refs.c
index a43b814a09..d46d940dae 100644
--- a/libavcodec/h264_refs.c
+++ b/libavcodec/h264_refs.c
@@ -181,6 +181,22 @@ static void h264_initialise_ref_list(H264Context *h, H264SliceContext *sl)
         if (len < sl->ref_count[0])
             memset(&sl->ref_list[0][len], 0, sizeof(H264Ref) * (sl->ref_count[0] - len));
     }
+#ifdef TRACE
+    for (i = 0; i < sl->ref_count[0]; i++) {
+        ff_tlog(h->avctx, "List0: %s fn:%d 0x%p\n",
+                (sl->ref_list[0][i].parent ? (sl->ref_list[0][i].parent->long_ref ? "LT" : "ST") : "??"),
+                sl->ref_list[0][i].pic_id,
+                sl->ref_list[0][i].data[0]);
+    }
+    if (sl->slice_type_nos == AV_PICTURE_TYPE_B) {
+        for (i = 0; i < sl->ref_count[1]; i++) {
+            ff_tlog(h->avctx, "List1: %s fn:%d 0x%p\n",
+                    (sl->ref_list[1][i].parent ? (sl->ref_list[1][i].parent->long_ref ? "LT" : "ST") : "??"),
+                    sl->ref_list[1][i].pic_id,
+                    sl->ref_list[1][i].data[0]);
+        }
+    }
+#endif
 
     for (j = 0; j<1+(sl->slice_type_nos == AV_PICTURE_TYPE_B); j++) {
         for (i = 0; i < sl->ref_count[j]; i++) {