GstPlayer seems to have broken in 1.19.2 (possibly due to the port to use GstPlay?) when using GstPlayerVideoOverlayVideoRenderer. I noticed the problem with wxMediaCtrl in wxWidgets, but I can reproduce the same problem with the gst-examples/playback/player/gtk example.

Expected Behavior
GstPlayer still uses the overlay window.

Observed Behavior
GstPlayer fails to use the overlay window and produces these errors:

(gtk-play:198757): GLib-GObject-CRITICAL **: 15:47:47.674: g_object_get_property: assertion 'G_IS_OBJECT (object)' failed

** (gtk-play:198757): CRITICAL **: 15:47:47.674: gst_player_video_overlay_video_renderer_create_video_sink: assertion 'GST_IS_VIDEO_OVERLAY (video_overlay)' failed

Setup
    Operating System: Fedora 35
    Device: Computer
    **GStreamer Version: 1.19.2
    Command line:

Steps to reproduce the bug
    Roll gst-examples repository back to f8cbae9d (before it was ported to GstPlay).
    Make the below hacky patch to the gtk-play example (to force it to use GstPlayerVideoOverlayVideoRenderer instead of its own renderer).

diff --git a/playback/player/gtk/gtk-play.c b/playback/player/gtk/gtk-play.c
index 786458e..c461f01 100644
--- a/playback/player/gtk/gtk-play.c
+++ b/playback/player/gtk/gtk-play.c
@@ -1425,7 +1425,7 @@ create_ui (GtkPlay * play)
       GTK_WINDOW (play));
 
   play->renderer = gst_player_gtk_video_renderer_new ();
-  if (play->renderer) {
+  if (0 /*play->renderer*/) {
     play->video_area =
         gst_player_gtk_video_renderer_get_widget (GST_PLAYER_GTK_VIDEO_RENDERER
         (play->renderer));

    Run it, select a video, observe that the video opens its own window (instead of using the overlay) and observe the error messages/warnings.

How reproducible is the bug?
100%

Note, this bug has been fixed upstream and I would like to get the fixes backported to F35.