video: add seqnum getters for overlay compositions and rectangles

API: gst_video_overlay_composition_get_seqnum()
API: gst_video_overlay_rectangle_get_seqnum()

gst-libs/gst/video/video-overlay-composition.c

@@ -602,6 +602,27 @@ copy:
   return writable_comp;
 }
 
+/**
+ * gst_video_overlay_composition_get_seqnum:
+ * @comp: a #GstVideoOverlayComposition
+ *
+ * Returns the sequence number of this composition. Sequence numbers are
+ * monotonically increasing and unique for overlay compositions and rectangles
+ * (meaning there will never be a rectangle with the same sequence number as
+ * a composition).
+ *
+ * Returns: the sequence number of @comp
+ *
+ * Since: 0.10.36
+ */
+guint
+gst_video_overlay_composition_get_seqnum (GstVideoOverlayComposition * comp)
+{
+  g_return_val_if_fail (GST_IS_VIDEO_OVERLAY_COMPOSITION (comp), 0);
+
+  return comp->seq_num;
+}
+
 /* ------------------------------ rectangles ------------------------------ -*/
 
 static void gst_video_overlay_rectangle_instance_init (GstMiniObject * miniobj);
@@ -958,3 +979,24 @@ gst_video_overlay_rectangle_copy (GstVideoOverlayRectangle * rectangle)
 
   return copy;
 }
+
+/**
+ * gst_video_overlay_rectangle_get_seqnum:
+ * @rectangle: a #GstVideoOverlayRectangle
+ *
+ * Returns the sequence number of this rectangle. Sequence numbers are
+ * monotonically increasing and unique for overlay compositions and rectangles
+ * (meaning there will never be a rectangle with the same sequence number as
+ * a composition).
+ *
+ * Returns: the sequence number of @rectangle
+ *
+ * Since: 0.10.36
+ */
+guint
+gst_video_overlay_rectangle_get_seqnum (GstVideoOverlayRectangle * rectangle)
+{
+  g_return_val_if_fail (GST_IS_VIDEO_OVERLAY_RECTANGLE (rectangle), 0);
+
+  return rectangle->seq_num;
+}

gst-libs/gst/video/video-overlay-composition.h

@@ -114,6 +114,8 @@ GstVideoOverlayRectangle *   gst_video_overlay_rectangle_new_argb (GstBuffer * p
 
 GstVideoOverlayRectangle *   gst_video_overlay_rectangle_copy     (GstVideoOverlayRectangle * rectangle);
 
+guint                        gst_video_overlay_rectangle_get_seqnum (GstVideoOverlayRectangle  * rectangle);
+
 void                         gst_video_overlay_rectangle_set_render_rectangle     (GstVideoOverlayRectangle  * rectangle,
                                                                                    gint                        render_x,
                                                                                    gint                        render_y,
@@ -214,6 +216,8 @@ guint                        gst_video_overlay_composition_n_rectangles  (GstVid
 
 GstVideoOverlayRectangle *   gst_video_overlay_composition_get_rectangle (GstVideoOverlayComposition * comp, guint n);
 
+guint                        gst_video_overlay_composition_get_seqnum    (GstVideoOverlayComposition * comp);
+
 /* blend composition onto raw video buffer */
 
 void                         gst_video_overlay_composition_blend         (GstVideoOverlayComposition * comp,

tests/check/libs/video.c

@@ -783,6 +783,7 @@ GST_START_TEST (test_overlay_composition)
   GstVideoOverlayComposition *comp1, *comp2;
   GstVideoOverlayRectangle *rect1, *rect2;
   GstBuffer *pix1, *pix2, *buf;
+  guint seq1, seq2;
   guint w, h, stride;
   gint x, y;
 
@@ -800,6 +801,11 @@ GST_START_TEST (test_overlay_composition)
   fail_unless (gst_video_overlay_composition_get_rectangle (comp1, 0) == rect1);
   fail_unless (gst_video_overlay_composition_get_rectangle (comp1, 1) == NULL);
 
+  /* rectangle was created first, sequence number should be smaller */
+  seq1 = gst_video_overlay_rectangle_get_seqnum (rect1);
+  seq2 = gst_video_overlay_composition_get_seqnum (comp1);
+  fail_unless (seq1 < seq2);
+
   /* composition took own ref, so refcount is 2 now, so this should fail */
   ASSERT_CRITICAL (gst_video_overlay_rectangle_set_render_rectangle (rect1, 50,
           600, 300, 50));
@@ -813,6 +819,9 @@ GST_START_TEST (test_overlay_composition)
   fail_unless (gst_video_overlay_composition_get_rectangle (comp2, 0) == rect1);
   fail_unless (gst_video_overlay_composition_get_rectangle (comp2, 1) == NULL);
 
+  fail_unless (seq1 < gst_video_overlay_composition_get_seqnum (comp2));
+  fail_unless (seq2 < gst_video_overlay_composition_get_seqnum (comp2));
+
   /* now refcount is 2 again because comp2 has also taken a ref, so must fail */
   ASSERT_CRITICAL (gst_video_overlay_rectangle_set_render_rectangle (rect1, 0,
           0, 1, 1));

win32/common/libgstvideo.def

@@ -39,6 +39,7 @@ EXPORTS
 	gst_video_overlay_composition_blend
 	gst_video_overlay_composition_copy
 	gst_video_overlay_composition_get_rectangle
+	gst_video_overlay_composition_get_seqnum
 	gst_video_overlay_composition_get_type
 	gst_video_overlay_composition_make_writable
 	gst_video_overlay_composition_n_rectangles
@@ -47,6 +48,7 @@ EXPORTS
 	gst_video_overlay_rectangle_get_pixels_argb
 	gst_video_overlay_rectangle_get_pixels_unscaled_argb
 	gst_video_overlay_rectangle_get_render_rectangle
+	gst_video_overlay_rectangle_get_seqnum
 	gst_video_overlay_rectangle_get_type
 	gst_video_overlay_rectangle_new_argb
 	gst_video_overlay_rectangle_set_render_rectangle