avcodec/h264: Avoid using gray gap frames as references

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

1 files changed, 11 insertions, 0 deletions

diff --git a/libavcodec/h264_refs.c b/libavcodec/h264_refs.c
index 92778e737a..9bc7b20988 100644
--- a/libavcodec/h264_refs.c
+++ b/libavcodec/h264_refs.c
@@ -410,6 +410,17 @@ int ff_h264_build_ref_list(H264Context *h, H264SliceContext *sl)
                 else
                     return -1;
             }
+            if (h->noref_gray>0 && sl->ref_list[list][index].parent->gray && h->non_gray) {
+                for (int j=0; j<sl->list_count; j++) {
+                    int list2 = (list+j)&1;
+                    if (h->default_ref[list2].parent && !h->default_ref[list2].parent->gray
+                        && !(!FIELD_PICTURE(h) && (h->default_ref[list2].reference&3) != 3)) {
+                        sl->ref_list[list][index] = h->default_ref[list2];
+                        av_log(h, AV_LOG_DEBUG, "replacement of gray gap frame\n");
+                        break;
+                    }
+                }
+            }
             av_assert0(av_buffer_get_ref_count(sl->ref_list[list][index].parent->f->buf[0]) > 0);
         }
     }