codecs: h264dec: Add a flag to record whether picture is reference.

The picture->ref field will change from time to time according to decoder's
state and reference sliding window. We need another flag to record whether
the picture is a reference picture when it is created, and this can help
the bumping check.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2373>

3 files changed, 11 insertions, 2 deletions

diff --git a/gst-libs/gst/codecs/gsth264decoder.c b/gst-libs/gst/codecs/gsth264decoder.c
index 189ed2620..da70095a6 100644
--- a/gst-libs/gst/codecs/gsth264decoder.c
+++ b/gst-libs/gst/codecs/gsth264decoder.c
@@ -2199,6 +2199,7 @@ gst_h264_decoder_init_gap_picture (GstH264Decoder * self,
   picture->frame_num = picture->pic_num = frame_num;
   picture->dec_ref_pic_marking.adaptive_ref_pic_marking_mode_flag = FALSE;
   picture->ref = GST_H264_PICTURE_REF_SHORT_TERM;
+  picture->ref_pic = TRUE;
   picture->dec_ref_pic_marking.long_term_reference_flag = FALSE;
   picture->field = GST_H264_PICTURE_FIELD_FRAME;
 
diff --git a/gst-libs/gst/codecs/gsth264picture.c b/gst-libs/gst/codecs/gsth264picture.c
index e7bf8c687..417986c62 100644
--- a/gst-libs/gst/codecs/gsth264picture.c
+++ b/gst-libs/gst/codecs/gsth264picture.c
@@ -707,7 +707,7 @@ gst_h264_dpb_needs_bump (GstH264Dpb * dpb, GstH264Picture * to_insert,
     return FALSE;
   }
 
-  if (to_insert->ref != GST_H264_PICTURE_REF_NONE) {
+  if (to_insert->ref_pic) {
     GST_TRACE ("No empty frame buffer for ref frame, need bumping.");
     return TRUE;
   }
@@ -1055,7 +1055,13 @@ gst_h264_picture_set_reference (GstH264Picture * picture,
   g_return_if_fail (picture != NULL);
 
   picture->ref = reference;
+  if (reference > GST_H264_PICTURE_REF_NONE)
+    picture->ref_pic = TRUE;
 
-  if (other_field && picture->other_field)
+  if (other_field && picture->other_field) {
     picture->other_field->ref = reference;
+
+    if (reference > GST_H264_PICTURE_REF_NONE)
+      picture->other_field->ref_pic = TRUE;
+  }
 }
diff --git a/gst-libs/gst/codecs/gsth264picture.h b/gst-libs/gst/codecs/gsth264picture.h
index 4e9a7a0b8..962ed5e66 100644
--- a/gst-libs/gst/codecs/gsth264picture.h
+++ b/gst-libs/gst/codecs/gsth264picture.h
@@ -143,6 +143,8 @@ struct _GstH264Picture
   gboolean idr;
   gint idr_pic_id;
   GstH264PictureReference ref;
+  /* Whether a reference picture. */
+  gboolean ref_pic;
   gboolean needed_for_output;
   gboolean mem_mgmt_5;