1 /* GStreamer Video Overlay interface
2 * Copyright (C) 2003 Ronald Bultje <rbultje@ronald.bitfreak.net>
3 * Copyright (C) 2011 Tim-Philipp Müller <tim@centricular.net>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
21 * SECTION:gstvideooverlay
22 * @title: GstVideoOverlay
23 * @short_description: Interface for setting/getting a window system resource
24 * on elements supporting it to configure a window into which to render a
27 * The #GstVideoOverlay interface is used for 2 main purposes :
29 * * To get a grab on the Window where the video sink element is going to render.
30 * This is achieved by either being informed about the Window identifier that
31 * the video sink element generated, or by forcing the video sink element to use
32 * a specific Window identifier for rendering.
33 * * To force a redrawing of the latest video frame the video sink element
34 * displayed on the Window. Indeed if the #GstPipeline is in #GST_STATE_PAUSED
35 * state, moving the Window around will damage its content. Application
36 * developers will want to handle the Expose events themselves and force the
37 * video sink element to refresh the Window's content.
39 * Using the Window created by the video sink is probably the simplest scenario,
40 * in some cases, though, it might not be flexible enough for application
41 * developers if they need to catch events such as mouse moves and button
44 * Setting a specific Window identifier on the video sink element is the most
45 * flexible solution but it has some issues. Indeed the application needs to set
46 * its Window identifier at the right time to avoid internal Window creation
47 * from the video sink element. To solve this issue a #GstMessage is posted on
48 * the bus to inform the application that it should set the Window identifier
49 * immediately. Here is an example on how to do that correctly:
51 * static GstBusSyncReply
52 * create_window (GstBus * bus, GstMessage * message, GstPipeline * pipeline)
54 * // ignore anything but 'prepare-window-handle' element messages
55 * if (!gst_is_video_overlay_prepare_window_handle_message (message))
56 * return GST_BUS_PASS;
58 * win = XCreateSimpleWindow (disp, root, 0, 0, 320, 240, 0, 0, 0);
60 * XSetWindowBackgroundPixmap (disp, win, None);
62 * XMapRaised (disp, win);
64 * XSync (disp, FALSE);
66 * gst_video_overlay_set_window_handle (GST_VIDEO_OVERLAY (GST_MESSAGE_SRC (message)),
69 * gst_message_unref (message);
71 * return GST_BUS_DROP;
75 * main (int argc, char **argv)
78 * bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
79 * gst_bus_set_sync_handler (bus, (GstBusSyncHandler) create_window, pipeline,
85 * ## Two basic usage scenarios
87 * There are two basic usage scenarios: in the simplest case, the application
88 * uses #playbin or #plasink or knows exactly what particular element is used
89 * for video output, which is usually the case when the application creates
90 * the videosink to use (e.g. #xvimagesink, #ximagesink, etc.) itself; in this
91 * case, the application can just create the videosink element, create and
92 * realize the window to render the video on and then
93 * call gst_video_overlay_set_window_handle() directly with the XID or native
94 * window handle, before starting up the pipeline.
95 * As #playbin and #playsink implement the video overlay interface and proxy
96 * it transparently to the actual video sink even if it is created later, this
97 * case also applies when using these elements.
99 * In the other and more common case, the application does not know in advance
100 * what GStreamer video sink element will be used for video output. This is
101 * usually the case when an element such as #autovideosink is used.
102 * In this case, the video sink element itself is created
103 * asynchronously from a GStreamer streaming thread some time after the
104 * pipeline has been started up. When that happens, however, the video sink
105 * will need to know right then whether to render onto an already existing
106 * application window or whether to create its own window. This is when it
107 * posts a prepare-window-handle message, and that is also why this message needs
108 * to be handled in a sync bus handler which will be called from the streaming
109 * thread directly (because the video sink will need an answer right then).
111 * As response to the prepare-window-handle element message in the bus sync
112 * handler, the application may use gst_video_overlay_set_window_handle() to tell
113 * the video sink to render onto an existing window surface. At this point the
114 * application should already have obtained the window handle / XID, so it
115 * just needs to set it. It is generally not advisable to call any GUI toolkit
116 * functions or window system functions from the streaming thread in which the
117 * prepare-window-handle message is handled, because most GUI toolkits and
118 * windowing systems are not thread-safe at all and a lot of care would be
119 * required to co-ordinate the toolkit and window system calls of the
120 * different threads (Gtk+ users please note: prior to Gtk+ 2.18
121 * GDK_WINDOW_XID() was just a simple structure access, so generally fine to do
122 * within the bus sync handler; this macro was changed to a function call in
123 * Gtk+ 2.18 and later, which is likely to cause problems when called from a
124 * sync handler; see below for a better approach without GDK_WINDOW_XID()
125 * used in the callback).
127 * ## GstVideoOverlay and Gtk+
130 * #include <gst/video/videooverlay.h>
131 * #include <gtk/gtk.h>
132 * #ifdef GDK_WINDOWING_X11
133 * #include <gdk/gdkx.h> // for GDK_WINDOW_XID
135 * #ifdef GDK_WINDOWING_WIN32
136 * #include <gdk/gdkwin32.h> // for GDK_WINDOW_HWND
139 * static guintptr video_window_handle = 0;
141 * static GstBusSyncReply
142 * bus_sync_handler (GstBus * bus, GstMessage * message, gpointer user_data)
144 * // ignore anything but 'prepare-window-handle' element messages
145 * if (!gst_is_video_overlay_prepare_window_handle_message (message))
146 * return GST_BUS_PASS;
148 * if (video_window_handle != 0) {
149 * GstVideoOverlay *overlay;
151 * // GST_MESSAGE_SRC (message) will be the video sink element
152 * overlay = GST_VIDEO_OVERLAY (GST_MESSAGE_SRC (message));
153 * gst_video_overlay_set_window_handle (overlay, video_window_handle);
155 * g_warning ("Should have obtained video_window_handle by now!");
158 * gst_message_unref (message);
159 * return GST_BUS_DROP;
163 * video_widget_realize_cb (GtkWidget * widget, gpointer data)
165 * #if GTK_CHECK_VERSION(2,18,0)
166 * // Tell Gtk+/Gdk to create a native window for this widget instead of
167 * // drawing onto the parent widget.
168 * // This is here just for pedagogical purposes, GDK_WINDOW_XID will call
169 * // it as well in newer Gtk versions
170 * if (!gdk_window_ensure_native (widget->window))
171 * g_error ("Couldn't create native window needed for GstVideoOverlay!");
174 * #ifdef GDK_WINDOWING_X11
176 * gulong xid = GDK_WINDOW_XID (gtk_widget_get_window (video_window));
177 * video_window_handle = xid;
180 * #ifdef GDK_WINDOWING_WIN32
182 * HWND wnd = GDK_WINDOW_HWND (gtk_widget_get_window (video_window));
183 * video_window_handle = (guintptr) wnd;
189 * main (int argc, char **argv)
191 * GtkWidget *video_window;
192 * GtkWidget *app_window;
194 * app_window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
196 * video_window = gtk_drawing_area_new ();
197 * g_signal_connect (video_window, "realize",
198 * G_CALLBACK (video_widget_realize_cb), NULL);
199 * gtk_widget_set_double_buffered (video_window, FALSE);
201 * // usually the video_window will not be directly embedded into the
202 * // application window like this, but there will be many other widgets
203 * // and the video window will be embedded in one of them instead
204 * gtk_container_add (GTK_CONTAINER (ap_window), video_window);
207 * gtk_widget_show_all (app_window);
209 * // realize window now so that the video window gets created and we can
210 * // obtain its XID/HWND before the pipeline is started up and the videosink
211 * // asks for the XID/HWND of the window to render onto
212 * gtk_widget_realize (video_window);
214 * // we should have the XID/HWND now
215 * g_assert (video_window_handle != 0);
217 * // set up sync handler for setting the xid once the pipeline is started
218 * bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
219 * gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bus_sync_handler, NULL,
221 * gst_object_unref (bus);
223 * gst_element_set_state (pipeline, GST_STATE_PLAYING);
228 * ## GstVideoOverlay and Qt
231 * #include <glib.h>
232 * #include <gst/gst.h>
233 * #include <gst/video/videooverlay.h>
235 * #include <QApplication>
236 * #include <QTimer>
237 * #include <QWidget>
239 * int main(int argc, char *argv[])
241 * if (!g_thread_supported ())
242 * g_thread_init (NULL);
244 * gst_init (&argc, &argv);
245 * QApplication app(argc, argv);
246 * app.connect(&app, SIGNAL(lastWindowClosed()), &app, SLOT(quit ()));
248 * // prepare the pipeline
250 * GstElement *pipeline = gst_pipeline_new ("xvoverlay");
251 * GstElement *src = gst_element_factory_make ("videotestsrc", NULL);
252 * GstElement *sink = gst_element_factory_make ("xvimagesink", NULL);
253 * gst_bin_add_many (GST_BIN (pipeline), src, sink, NULL);
254 * gst_element_link (src, sink);
259 * window.resize(320, 240);
262 * WId xwinid = window.winId();
263 * gst_video_overlay_set_window_handle (GST_VIDEO_OVERLAY (sink), xwinid);
265 * // run the pipeline
267 * GstStateChangeReturn sret = gst_element_set_state (pipeline,
268 * GST_STATE_PLAYING);
269 * if (sret == GST_STATE_CHANGE_FAILURE) {
270 * gst_element_set_state (pipeline, GST_STATE_NULL);
271 * gst_object_unref (pipeline);
272 * // Exit application
273 * QTimer::singleShot(0, QApplication::activeWindow(), SLOT(quit()));
276 * int ret = app.exec();
279 * gst_element_set_state (pipeline, GST_STATE_NULL);
280 * gst_object_unref (pipeline);
292 #include "videooverlay.h"
296 PROP_RENDER_RECTANGLE,
299 GST_DEBUG_CATEGORY_STATIC (gst_video_overlay_debug);
300 #define GST_CAT_DEFAULT gst_video_overlay_debug
303 gst_video_overlay_get_type (void)
305 static GType gst_video_overlay_type = 0;
307 if (!gst_video_overlay_type) {
308 static const GTypeInfo gst_video_overlay_info = {
309 sizeof (GstVideoOverlayInterface),
320 gst_video_overlay_type = g_type_register_static (G_TYPE_INTERFACE,
321 "GstVideoOverlay", &gst_video_overlay_info, 0);
323 GST_DEBUG_CATEGORY_INIT (gst_video_overlay_debug, "videooverlay", 0,
324 "videooverlay interface");
327 return gst_video_overlay_type;
330 #ifdef TIZEN_FEATURE_WAYLAND_ENHANCEMENT
332 * gst_video_overlay_set_wl_window_wl_surface_id:
333 * @overlay: a #GstVideoOverlay to set the window on.
334 * @wl_surface_id: a global resource id of wl_surface referencing the wayland window.
336 * This will call the video overlay's set_wl_window_wl_surface_id method. You
337 * should use this medtod to tell to an overlay to display video output to a
338 * specific window(e.g. an Wayland Window on Wayland).
339 * But you can also set handle to wayland videosink with gst_video_overlay_set_wl_window_wl_surface_id().
342 gst_video_overlay_set_wl_window_wl_surface_id (GstVideoOverlay * overlay,
345 GstVideoOverlayInterface *iface;
347 g_return_if_fail (overlay != NULL);
348 g_return_if_fail (GST_IS_VIDEO_OVERLAY (overlay));
350 iface = GST_VIDEO_OVERLAY_GET_INTERFACE (overlay);
352 if (iface->set_wl_window_wl_surface_id) {
353 iface->set_wl_window_wl_surface_id (overlay, wl_surface_id);
358 * gst_video_overlay_set_wl_window_exported_shell_handle:
359 * @overlay: a #GstVideoOverlay to set the window on.
360 * @exported_shell_handle: a shell handle exported by wayland window for synchronization between UI and video
362 * This will call the video overlay's set_wl_window_exported_shell_handle method. You
363 * should use this medtod to tell to an overlay to display video output to a
364 * specific window(e.g. an Wayland Window on Wayland).
365 * But you can also set handle to wayland videosink with gst_video_overlay_set_wl_window_exported_shell_handle().
368 gst_video_overlay_set_wl_window_exported_shell_handle (GstVideoOverlay * overlay,
369 const char *exported_shell_handle)
371 GstVideoOverlayInterface *iface;
373 g_return_if_fail (overlay != NULL);
374 g_return_if_fail (GST_IS_VIDEO_OVERLAY (overlay));
376 iface = GST_VIDEO_OVERLAY_GET_INTERFACE (overlay);
378 if (iface->set_wl_window_exported_shell_handle) {
379 iface->set_wl_window_exported_shell_handle (overlay, exported_shell_handle);
386 * gst_video_overlay_set_display_roi_area:
387 * @overlay: a #GstVideoOverlay
388 * @x: the horizontal offset of the render area inside the window
389 * @y: the vertical offset of the render area inside the window
390 * @width: the width of the render area inside the window
391 * @height: the height of the render area inside the window
393 * Set the ROI(Region of Interest) area of wayland window.
394 * Returns: %FALSE if not supported by the sink.
397 gst_video_overlay_set_display_roi_area (GstVideoOverlay * overlay,
398 gint x, gint y, gint width, gint height)
400 GstVideoOverlayInterface *iface;
402 g_return_val_if_fail (overlay != NULL, FALSE);
403 g_return_val_if_fail (GST_IS_VIDEO_OVERLAY (overlay), FALSE);
404 g_return_val_if_fail (width > 0 && height > 0, FALSE);
406 iface = GST_VIDEO_OVERLAY_GET_INTERFACE (overlay);
408 if (iface->set_display_roi_area) {
409 iface->set_display_roi_area (overlay, x, y, width, height);
416 * gst_video_overlay_set_video_roi_area:
417 * @overlay: a #GstVideoOverlay
418 * @x_scale: x coordinate ratio value of video source area
419 * based on video width size, valid range is from 0.0 to 1.0.
420 * @y_scale: y coordinate ratio value of video source area
421 * based on video width size, valid range is from 0.0 to 1.0.
422 * @w_scale: width ratio value of the video source area
423 * based on video width size, valid range is from greater than 0.0 to 1.0.
424 * @h_scale: height ratio value of the video source area
425 * based on video width size, valid range is from greater than 0.0 to 1.0.
427 * Sets the ROI(Region Of Interest) area of video source.
428 * Returns: %FALSE if not supported by the sink.
431 gst_video_overlay_set_video_roi_area (GstVideoOverlay * overlay,
432 gdouble x_scale, gdouble y_scale, gdouble w_scale, gdouble h_scale)
434 GstVideoOverlayInterface *iface;
436 g_return_val_if_fail (overlay != NULL, FALSE);
437 g_return_val_if_fail (GST_IS_VIDEO_OVERLAY (overlay), FALSE);
438 g_return_val_if_fail (x_scale >= 0.0 && x_scale <= 1.0, FALSE);
439 g_return_val_if_fail (y_scale >= 0.0 && y_scale <= 1.0, FALSE);
440 g_return_val_if_fail (w_scale > 0.0 && w_scale <= 1.0, FALSE);
441 g_return_val_if_fail (h_scale > 0.0 && h_scale <= 1.0, FALSE);
443 iface = GST_VIDEO_OVERLAY_GET_INTERFACE (overlay);
445 if (iface->set_video_roi_area) {
446 iface->set_video_roi_area (overlay, x_scale, y_scale, w_scale, h_scale);
453 * gst_video_overlay_set_window_handle:
454 * @overlay: a #GstVideoOverlay to set the window on.
455 * @handle: a handle referencing the window.
457 * This will call the video overlay's set_window_handle method. You
458 * should use this method to tell to an overlay to display video output to a
459 * specific window (e.g. an XWindow on X11). Passing 0 as the @handle will
460 * tell the overlay to stop using that window and create an internal one.
463 gst_video_overlay_set_window_handle (GstVideoOverlay * overlay, guintptr handle)
465 GstVideoOverlayInterface *iface;
467 g_return_if_fail (overlay != NULL);
468 g_return_if_fail (GST_IS_VIDEO_OVERLAY (overlay));
470 iface = GST_VIDEO_OVERLAY_GET_INTERFACE (overlay);
472 if (iface->set_window_handle) {
473 iface->set_window_handle (overlay, handle);
478 * gst_video_overlay_got_window_handle:
479 * @overlay: a #GstVideoOverlay which got a window
480 * @handle: a platform-specific handle referencing the window
482 * This will post a "have-window-handle" element message on the bus.
484 * This function should only be used by video overlay plugin developers.
487 gst_video_overlay_got_window_handle (GstVideoOverlay * overlay, guintptr handle)
492 g_return_if_fail (overlay != NULL);
493 g_return_if_fail (GST_IS_VIDEO_OVERLAY (overlay));
495 GST_LOG_OBJECT (GST_OBJECT (overlay), "window_handle = %p", (gpointer)
497 s = gst_structure_new ("have-window-handle",
498 "window-handle", G_TYPE_UINT64, (guint64) handle, NULL);
499 msg = gst_message_new_element (GST_OBJECT (overlay), s);
500 gst_element_post_message (GST_ELEMENT (overlay), msg);
504 * gst_video_overlay_prepare_window_handle:
505 * @overlay: a #GstVideoOverlay which does not yet have an Window handle set
507 * This will post a "prepare-window-handle" element message on the bus
508 * to give applications an opportunity to call
509 * gst_video_overlay_set_window_handle() before a plugin creates its own
512 * This function should only be used by video overlay plugin developers.
515 gst_video_overlay_prepare_window_handle (GstVideoOverlay * overlay)
520 g_return_if_fail (overlay != NULL);
521 g_return_if_fail (GST_IS_VIDEO_OVERLAY (overlay));
523 GST_LOG_OBJECT (GST_OBJECT (overlay), "prepare window handle");
524 s = gst_structure_new_empty ("prepare-window-handle");
525 msg = gst_message_new_element (GST_OBJECT (overlay), s);
526 gst_element_post_message (GST_ELEMENT (overlay), msg);
530 * gst_video_overlay_expose:
531 * @overlay: a #GstVideoOverlay to expose.
533 * Tell an overlay that it has been exposed. This will redraw the current frame
534 * in the drawable even if the pipeline is PAUSED.
537 gst_video_overlay_expose (GstVideoOverlay * overlay)
539 GstVideoOverlayInterface *iface;
541 g_return_if_fail (overlay != NULL);
542 g_return_if_fail (GST_IS_VIDEO_OVERLAY (overlay));
544 iface = GST_VIDEO_OVERLAY_GET_INTERFACE (overlay);
547 iface->expose (overlay);
552 * gst_video_overlay_handle_events:
553 * @overlay: a #GstVideoOverlay to expose.
554 * @handle_events: a #gboolean indicating if events should be handled or not.
556 * Tell an overlay that it should handle events from the window system. These
557 * events are forwarded upstream as navigation events. In some window system,
558 * events are not propagated in the window hierarchy if a client is listening
559 * for them. This method allows you to disable events handling completely
560 * from the #GstVideoOverlay.
563 gst_video_overlay_handle_events (GstVideoOverlay * overlay,
564 gboolean handle_events)
566 GstVideoOverlayInterface *iface;
568 g_return_if_fail (overlay != NULL);
569 g_return_if_fail (GST_IS_VIDEO_OVERLAY (overlay));
571 iface = GST_VIDEO_OVERLAY_GET_INTERFACE (overlay);
573 if (iface->handle_events) {
574 iface->handle_events (overlay, handle_events);
579 * gst_video_overlay_set_render_rectangle:
580 * @overlay: a #GstVideoOverlay
581 * @x: the horizontal offset of the render area inside the window
582 * @y: the vertical offset of the render area inside the window
583 * @width: the width of the render area inside the window
584 * @height: the height of the render area inside the window
586 * Configure a subregion as a video target within the window set by
587 * gst_video_overlay_set_window_handle(). If this is not used or not supported
588 * the video will fill the area of the window set as the overlay to 100%.
589 * By specifying the rectangle, the video can be overlayed to a specific region
590 * of that window only. After setting the new rectangle one should call
591 * gst_video_overlay_expose() to force a redraw. To unset the region pass -1 for
592 * the @width and @height parameters.
594 * This method is needed for non fullscreen video overlay in UI toolkits that
595 * do not support subwindows.
597 * Returns: %FALSE if not supported by the sink.
600 gst_video_overlay_set_render_rectangle (GstVideoOverlay * overlay,
601 gint x, gint y, gint width, gint height)
603 GstVideoOverlayInterface *iface;
605 g_return_val_if_fail (overlay != NULL, FALSE);
606 g_return_val_if_fail (GST_IS_VIDEO_OVERLAY (overlay), FALSE);
607 g_return_val_if_fail ((width == -1 && height == -1) ||
608 (width > 0 && height > 0), FALSE);
610 iface = GST_VIDEO_OVERLAY_GET_INTERFACE (overlay);
612 if (iface->set_render_rectangle) {
613 iface->set_render_rectangle (overlay, x, y, width, height);
620 * gst_is_video_overlay_prepare_window_handle_message:
621 * @msg: a #GstMessage
623 * Convenience function to check if the given message is a
624 * "prepare-window-handle" message from a #GstVideoOverlay.
626 * Returns: whether @msg is a "prepare-window-handle" message
629 gst_is_video_overlay_prepare_window_handle_message (GstMessage * msg)
631 g_return_val_if_fail (msg != NULL, FALSE);
633 if (GST_MESSAGE_TYPE (msg) != GST_MESSAGE_ELEMENT)
636 return gst_message_has_name (msg, "prepare-window-handle");
641 * gst_video_overlay_install_properties:
642 * @oclass: The class on which the properties will be installed
643 * @last_prop_id: The first free property ID to use
645 * This helper shall be used by classes implementing the #GstVideoOverlay
646 * interface that want the render rectangle to be controllable using
647 * properties. This helper will install "render-rectangle" property into the
653 gst_video_overlay_install_properties (GObjectClass * oclass, gint last_prop_id)
655 g_object_class_install_property (oclass, last_prop_id + PROP_RENDER_RECTANGLE,
656 gst_param_spec_array ("render-rectangle", "Render Rectangle",
657 "The render rectangle ('<x, y, width, height>')",
658 g_param_spec_int ("rect-value", "Rectangle Value",
659 "One of x, y, width or height value.", G_MININT, G_MAXINT, -1,
660 G_PARAM_WRITABLE | G_PARAM_STATIC_STRINGS),
661 G_PARAM_WRITABLE | G_PARAM_STATIC_STRINGS));
665 * gst_video_overlay_set_property:
666 * @object: The instance on which the property is set
667 * @last_prop_id: The highest property ID.
668 * @property_id: The property ID
669 * @value: The #GValue to be set
671 * This helper shall be used by classes implementing the #GstVideoOverlay
672 * interface that want the render rectangle to be controllable using
673 * properties. This helper will parse and set the render rectangle calling
674 * gst_video_overlay_set_render_rectangle().
676 * Returns: %TRUE if the @property_id matches the GstVideoOverlay property
681 gst_video_overlay_set_property (GObject * object, gint last_prop_id,
682 guint property_id, const GValue * value)
684 gboolean ret = FALSE;
686 if (property_id == last_prop_id) {
692 if (gst_value_array_get_size (value) != 4)
695 for (i = 0; i < 4; i++) {
696 v = gst_value_array_get_value (value, i);
697 if (!G_VALUE_HOLDS_INT (v))
700 rect[i] = g_value_get_int (v);
703 gst_video_overlay_set_render_rectangle (GST_VIDEO_OVERLAY (object),
704 rect[0], rect[1], rect[2], rect[3]);
711 GValue string = G_VALUE_INIT;
713 g_value_init (&string, G_TYPE_STRING);
714 g_value_transform (value, &string);
716 g_critical ("Badly formated rectangle, must contains four gint (got '%s')",
717 g_value_get_string (&string));
719 g_value_unset (&string);