Display: Add a property to export the VA display handle.

Just like what we do in VA plugins. The display can be seen as a
generic gst object and we can add a property to get the internal
VA handle.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer-vaapi/-/merge_requests/435>

2 files changed, 18 insertions, 0 deletions

diff --git a/gst-libs/gst/vaapi/gstvaapidisplay.c b/gst-libs/gst/vaapi/gstvaapidisplay.c
index 26c216e7..878761af 100644
--- a/gst-libs/gst/vaapi/gstvaapidisplay.c
+++ b/gst-libs/gst/vaapi/gstvaapidisplay.c
@@ -86,6 +86,7 @@ enum
   PROP_SATURATION,
   PROP_BRIGHTNESS,
   PROP_CONTRAST,
+  PROP_VA_DISPLAY,
 
   N_PROPERTIES
 };
@@ -1123,6 +1124,11 @@ gst_vaapi_display_get_property (GObject * object, guint property_id,
   GstVaapiDisplay *display = GST_VAAPI_DISPLAY (object);
   const GstVaapiProperty *prop;
 
+  if (property_id == PROP_VA_DISPLAY) {
+    g_value_set_pointer (value, gst_vaapi_display_get_display (display));
+    return;
+  }
+
   if (!ensure_properties (display))
     return;
 
@@ -1224,6 +1230,15 @@ gst_vaapi_display_class_init (GstVaapiDisplayClass * klass)
       "contrast",
       "The display contrast value", 0.0, 2.0, 1.0, G_PARAM_READWRITE);
 
+  /**
+   * GstVaapiDisplay:va-display:
+   *
+   * The VA display handle, expressed as a #VADisplay.
+   */
+  g_properties[PROP_VA_DISPLAY] =
+      g_param_spec_pointer ("va-display", "VADisplay",
+      "VA Display handler", G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
+
   g_object_class_install_properties (object_class, N_PROPERTIES, g_properties);
   gst_type_mark_as_plugin_api (gst_vaapi_display_type_get_type (), 0);
 }
diff --git a/gst/vaapi/gstvaapivideocontext.c b/gst/vaapi/gstvaapivideocontext.c
index ae3af85d..cc2967b8 100644
--- a/gst/vaapi/gstvaapivideocontext.c
+++ b/gst/vaapi/gstvaapivideocontext.c
@@ -64,6 +64,9 @@ gst_vaapi_video_context_set_display (GstContext * context,
   structure = gst_context_writable_structure (context);
   gst_structure_set (structure, GST_VAAPI_DISPLAY_CONTEXT_TYPE_NAME,
       GST_TYPE_VAAPI_DISPLAY, display, NULL);
+  /* The outside user may access it as a generic Gobject. */
+  gst_structure_set (structure, "gst.vaapi.Display.GObject",
+      GST_TYPE_OBJECT, display, NULL);
 }
 
 GstContext *