Sets our main struct and passes it to the parent class
The Element parameter should usually be your videosink that you want to create your XOverlay with.
Tell an overlay that it has been exposed. This will redraw the current frame in the drawable even if the pipeline is PAUSED.
the main Gtk struct as a void*
This will post a "have-xwindow-id" element message on the bus. This function should only be used by video overlay plugin developers.
Tell an overlay that it should handle events from the window system. These events are forwared upstream as navigation events. In some window system, events are not propagated in the window hierarchy if a client is listening for them. This method allows you to disable events handling completely from the XOverlay.
This will post a "prepare-xwindow-id" element message on the bus to give applications an opportunity to call gst_x_overlay_set_xwindow_id() before a plugin creates its own window. This function should only be used by video overlay plugin developers.
This will call the video overlay's set_xwindow_id method. You should use this method to tell to a XOverlay to display video output to a specific XWindow. Passing 0 as the xwindow_id will tell the overlay to stop using that window and create an internal one.
the main Gtk struct
Description The XOverlay interface is used for 2 main purposes : To get a grab on the Window where the video sink element is going to render. This is achieved by either being informed about the Window identifier that the video sink element generated, or by forcing the video sink element to use a specific Window identifier for rendering. To force a redrawing of the latest video frame the video sink element displayed on the Window. Indeed if the GstPipeline is in GST_STATE_PAUSED state, moving the Window around will damage its content. Application developers will want to handle the Expose events themselves and force the video sink element to refresh the Window's content. Using the Window created by the video sink is probably the simplest scenario, in some cases, though, it might not be flexible enough for application developers if they need to catch events such as mouse moves and button clicks. Setting a specific Window identifier on the video sink element is the most flexible solution but it has some issues. Indeed the application needs to set its Window identifier at the right time to avoid internal Window creation from the video sink element. To solve this issue a GstMessage is posted on the bus to inform the application that it should set the Window identifier immediately. Here is an example on how to do that correctly: static GstBusSyncReply create_window (GstBus * bus, GstMessage * message, GstPipeline * pipeline) { * // ignore anything but 'prepare-xwindow-id' element messages * if (GST_MESSAGE_TYPE (message) != GST_MESSAGE_ELEMENT) * return GST_BUS_PASS; * if (!gst_structure_has_name (message->structure, "prepare-xwindow-id")) * return GST_BUS_PASS; * win = XCreateSimpleWindow (disp, root, 0, 0, 320, 240, 0, 0, 0); * XSetWindowBackgroundPixmap (disp, win, None); * XMapRaised (disp, win); * XSync (disp, FALSE); * gst_x_overlay_set_xwindow_id (GST_X_OVERLAY (GST_MESSAGE_SRC (message)), * win); * gst_message_unref (message); * return GST_BUS_DROP; } ... int main (int argc, char **argv) { * ... * bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline)); * gst_bus_set_sync_handler (bus, (GstBusSyncHandler) create_window, pipeline); * ... }