d3d11videosink: Add "emit-present" property

Controls the decision for "present" signal use, and
allows delayed "present" signal handler install via the property

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3176>

subprojects/gst-plugins-bad/sys/d3d11/gstd3d11videosink.cpp

@@ -64,6 +64,7 @@ enum
   PROP_GAMMA_MODE,
   PROP_PRIMARIES_MODE,
   PROP_DISPLAY_FORMAT,
+  PROP_EMIT_PRESENT,
 };
 
 #define DEFAULT_ADAPTER                   -1
@@ -75,6 +76,7 @@ enum
 #define DEFAULT_GAMMA_MODE                GST_VIDEO_GAMMA_MODE_NONE
 #define DEFAULT_PRIMARIES_MODE            GST_VIDEO_PRIMARIES_MODE_NONE
 #define DEFAULT_DISPLAY_FORMAT            DXGI_FORMAT_UNKNOWN
+#define DEFAULT_EMIT_PRESENT              FALSE
 
 #define GST_TYPE_D3D11_VIDEO_SINK_DISPLAY_FORMAT (gst_d3d11_video_sink_display_format_type())
 static GType
@@ -155,6 +157,7 @@ struct _GstD3D11VideoSink
   GstVideoGammaMode gamma_mode;
   GstVideoPrimariesMode primaries_mode;
   DXGI_FORMAT display_format;
+  gboolean emit_present;
 
   /* saved render rectangle until we have a window */
   GstVideoRectangle render_rect;
@@ -352,6 +355,19 @@ gst_d3d11_video_sink_class_init (GstD3D11VideoSinkClass * klass)
           DEFAULT_DISPLAY_FORMAT, (GParamFlags) (G_PARAM_READWRITE |
               GST_PARAM_MUTABLE_READY | G_PARAM_STATIC_STRINGS)));
 
+  /**
+   * GstD3D11VideoSink:emit-present:
+   *
+   * Emits "present" signal
+   *
+   * Since: 1.22
+   */
+  g_object_class_install_property (gobject_class, PROP_EMIT_PRESENT,
+      g_param_spec_boolean ("emit-present", "Emit present",
+          "Emits present signal", DEFAULT_EMIT_PRESENT,
+          (GParamFlags) (G_PARAM_READWRITE | GST_PARAM_MUTABLE_READY |
+              G_PARAM_STATIC_STRINGS)));
+
   /**
    * GstD3D11VideoSink::begin-draw:
    * @videosink: the #d3d11videosink
@@ -407,10 +423,6 @@ gst_d3d11_video_sink_class_init (GstD3D11VideoSinkClass * klass)
    * client should perform GPU operation from the thread where this signal
    * emitted.
    *
-   * If a client wants to listen this signal, the client must connect this
-   * signal before the first present. Otherwise this signal will not be
-   * emitted.
-   *
    * Since: 1.22
    */
   gst_d3d11_video_sink_signals[SIGNAL_PRESENT] =
@@ -466,6 +478,7 @@ gst_d3d11_video_sink_init (GstD3D11VideoSink * self)
   self->gamma_mode = DEFAULT_GAMMA_MODE;
   self->primaries_mode = DEFAULT_PRIMARIES_MODE;
   self->display_format = DEFAULT_DISPLAY_FORMAT;
+  self->emit_present = DEFAULT_EMIT_PRESENT;
 
   InitializeCriticalSection (&self->lock);
 }
@@ -524,6 +537,9 @@ gst_d3d11_videosink_set_property (GObject * object, guint prop_id,
     case PROP_DISPLAY_FORMAT:
       self->display_format = (DXGI_FORMAT) g_value_get_enum (value);
       break;
+    case PROP_EMIT_PRESENT:
+      self->emit_present = g_value_get_boolean (value);
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -572,6 +588,9 @@ gst_d3d11_videosink_get_property (GObject * object, guint prop_id,
     case PROP_DISPLAY_FORMAT:
       g_value_set_enum (value, self->display_format);
       break;
+    case PROP_EMIT_PRESENT:
+      g_value_set_boolean (value, self->emit_present);
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -869,7 +888,6 @@ static gboolean
 gst_d3d11_video_sink_prepare_window (GstD3D11VideoSink * self)
 {
   GstD3D11WindowNativeType window_type = GST_D3D11_WINDOW_NATIVE_TYPE_HWND;
-  gboolean emit_present = FALSE;
 
   if (self->window)
     return TRUE;
@@ -933,18 +951,12 @@ done:
     return FALSE;
   }
 
-  /* Emits present signal only if signal is connected for performance reason */
-  if (g_signal_has_handler_pending (self,
-          gst_d3d11_video_sink_signals[SIGNAL_PRESENT], 0, FALSE)) {
-    emit_present = TRUE;
-  }
-
   g_object_set (self->window,
       "force-aspect-ratio", self->force_aspect_ratio,
       "fullscreen-toggle-mode", self->fullscreen_toggle_mode,
       "fullscreen", self->fullscreen,
       "enable-navigation-events", self->enable_navigation_events,
-      "emit-present", emit_present, nullptr);
+      "emit-present", self->emit_present, nullptr);
 
   gst_d3d11_window_set_orientation (self->window, self->selected_method);
 

subprojects/gst-plugins-bad/tests/examples/d3d11/d3d11videosink-present.cpp

@@ -616,6 +616,9 @@ main (gint argc, gchar ** argv)
   context.sink = gst_element_factory_make ("d3d11videosink", nullptr);
   g_assert (context.sink);
 
+  /* Enables present signal */
+  g_object_set (context.sink, "emit-present", TRUE, nullptr);
+
   /* D2D <-> DXGI interop requires BGRA format */
   g_object_set (context.sink, "display-format", DXGI_FORMAT_B8G8R8A8_UNORM,
       nullptr);