codecs: h264picture: Count only complete complementary field pair for dpb fullness...

Our DPB implementation was designed as such that allowing
temporary DPB overflow in the middle of field picture decoding
and incomplete field pair should not trigger DPB bumping.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1947>

diff --git a/gst-libs/gst/codecs/gsth264picture.c b/gst-libs/gst/codecs/gsth264picture.c
index be5013d20e17ded212b9eb43cda5acb4a8422385..90fa1c3469fcd1c137c2d858b9eb530a873ee875 100644 (file)
--- a/gst-libs/gst/codecs/gsth264picture.c
+++ b/gst-libs/gst/codecs/gsth264picture.c
@@ -596,7 +596,7 @@ gst_h264_dpb_has_empty_frame_buffer (GstH264Dpb * dpb)
   } else {
     gint i;
     gint count = 0;
-    /* Count pictures without second fields */
+    /* Count the number of complementary field pairs */
     for (i = 0; i < dpb->pic_list->len; i++) {
       GstH264Picture *picture =
           g_array_index (dpb->pic_list, GstH264Picture *, i);
@@ -604,7 +604,8 @@ gst_h264_dpb_has_empty_frame_buffer (GstH264Dpb * dpb)
       if (picture->second_field)
         continue;
 
-      count++;
+      if (GST_H264_PICTURE_IS_FRAME (picture) || picture->other_field)
+        count++;
     }
 
     if (count <= dpb->max_num_frames)