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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>GstVideoOverlay: GStreamer Base Plugins 1.0 Library Reference Manual</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="index.html" title="GStreamer Base Plugins 1.0 Library Reference Manual">
<link rel="up" href="gstreamer-video.html" title="Video Library">
<link rel="prev" href="GstVideoOrientation.html" title="GstVideoOrientation">
<link rel="next" href="gst-plugins-base-libs-GstVideoDecoder.html" title="GstVideoDecoder">
<meta name="generator" content="GTK-Doc V1.27 (XML mode)">
<link rel="stylesheet" href="style.css" type="text/css">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="5"><tr valign="middle">
<td width="100%" align="left" class="shortcuts">
<a href="#" class="shortcut">Top</a><span id="nav_description">  <span class="dim">|</span> 
                  <a href="#GstVideoOverlay.description" class="shortcut">Description</a></span><span id="nav_hierarchy">  <span class="dim">|</span> 
                  <a href="#GstVideoOverlay.object-hierarchy" class="shortcut">Object Hierarchy</a></span>
</td>
<td><a accesskey="h" href="index.html"><img src="home.png" width="16" height="16" border="0" alt="Home"></a></td>
<td><a accesskey="u" href="gstreamer-video.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td>
<td><a accesskey="p" href="GstVideoOrientation.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td>
<td><a accesskey="n" href="gst-plugins-base-libs-GstVideoDecoder.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td>
</tr></table>
<div class="refentry">
<a name="GstVideoOverlay"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="GstVideoOverlay.top_of_page"></a>GstVideoOverlay</span></h2>
<p>GstVideoOverlay — Interface for setting/getting a window system resource
   on elements supporting it to configure a window into which to render a
   video.</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
</tr></table></div>
<div class="refsect1">
<a name="GstVideoOverlay.functions"></a><h2>Functions</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="functions_return">
<col class="functions_name">
</colgroup>
<tbody>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="GstVideoOverlay.html#gst-video-overlay-got-window-handle" title="gst_video_overlay_got_window_handle ()">gst_video_overlay_got_window_handle</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="GstVideoOverlay.html#gst-video-overlay-set-window-handle" title="gst_video_overlay_set_window_handle ()">gst_video_overlay_set_window_handle</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="GstVideoOverlay.html#gst-video-overlay-prepare-window-handle" title="gst_video_overlay_prepare_window_handle ()">gst_video_overlay_prepare_window_handle</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="GstVideoOverlay.html#gst-video-overlay-expose" title="gst_video_overlay_expose ()">gst_video_overlay_expose</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="GstVideoOverlay.html#gst-video-overlay-handle-events" title="gst_video_overlay_handle_events ()">gst_video_overlay_handle_events</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="../glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
</td>
<td class="function_name">
<a class="link" href="GstVideoOverlay.html#gst-video-overlay-set-render-rectangle" title="gst_video_overlay_set_render_rectangle ()">gst_video_overlay_set_render_rectangle</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="../glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
</td>
<td class="function_name">
<a class="link" href="GstVideoOverlay.html#gst-is-video-overlay-prepare-window-handle-message" title="gst_is_video_overlay_prepare_window_handle_message ()">gst_is_video_overlay_prepare_window_handle_message</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="GstVideoOverlay.html#gst-video-overlay-install-properties" title="gst_video_overlay_install_properties ()">gst_video_overlay_install_properties</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="../glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
</td>
<td class="function_name">
<a class="link" href="GstVideoOverlay.html#gst-video-overlay-set-property" title="gst_video_overlay_set_property ()">gst_video_overlay_set_property</a> <span class="c_punctuation">()</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="GstVideoOverlay.other"></a><h2>Types and Values</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="name">
<col class="description">
</colgroup>
<tbody>
<tr>
<td class="datatype_keyword"> </td>
<td class="function_name"><a class="link" href="GstVideoOverlay.html#GstVideoOverlay-struct" title="GstVideoOverlay">GstVideoOverlay</a></td>
</tr>
<tr>
<td class="datatype_keyword">struct</td>
<td class="function_name"><a class="link" href="GstVideoOverlay.html#GstVideoOverlayInterface" title="struct GstVideoOverlayInterface">GstVideoOverlayInterface</a></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="GstVideoOverlay.object-hierarchy"></a><h2>Object Hierarchy</h2>
<pre class="screen">    <a href="/usr/share/gtk-doc/html/gobject/GTypeModule.html">GInterface</a>
    <span class="lineart">╰──</span> GstVideoOverlay
</pre>
</div>
<div class="refsect1">
<a name="GstVideoOverlay.includes"></a><h2>Includes</h2>
<pre class="synopsis">#include &lt;gst/video/videooverlay.h&gt;
</pre>
</div>
<div class="refsect1">
<a name="GstVideoOverlay.description"></a><h2>Description</h2>
<p>The <a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> interface is used for 2 main purposes :</p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem"><p>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.</p></li>
<li class="listitem"><p>To force a redrawing of the latest video frame the video sink element
displayed on the Window. Indeed if the <a href="../gstreamer-1.0/GstPipeline.html#GstPipeline-struct"><span class="type">GstPipeline</span></a> is in <a href="../gstreamer-1.0/GstElement.html#GST-STATE-PAUSED:CAPS"><span class="type">GST_STATE_PAUSED</span></a>
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.</p></li>
</ul></div>
<p>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.</p>
<p>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 <a href="../gstreamer-1.0/GstMessage.html#GstMessage-struct"><span class="type">GstMessage</span></a> 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:</p>
<div class="informalexample">
  <table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
    <tbody>
      <tr>
        <td class="listing_lines" align="right"><pre>1
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32</pre></td>
        <td class="listing_code"><pre class="programlisting"><span class="gtkdoc kwb">static</span> GstBusSyncReply
<span class="function">create_window</span> <span class="gtkdoc opt">(</span>GstBus <span class="gtkdoc opt">*</span> bus<span class="gtkdoc opt">,</span> GstMessage <span class="gtkdoc opt">*</span> message<span class="gtkdoc opt">,</span> GstPipeline <span class="gtkdoc opt">*</span> pipeline<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
 <span class="gtkdoc slc">// ignore anything but &apos;prepare-window-handle&apos; element messages</span>
 <span class="keyword">if</span> <span class="gtkdoc opt">(!</span><span class="function"><a href="GstVideoOverlay.html#gst-is-video-overlay-prepare-window-handle-message">gst_is_video_overlay_prepare_window_handle_message</a></span> <span class="gtkdoc opt">(</span>message<span class="gtkdoc opt">))</span>
   <span class="keyword">return</span> GST_BUS_PASS<span class="gtkdoc opt">;</span>

 win <span class="gtkdoc opt">=</span> <span class="function">XCreateSimpleWindow</span> <span class="gtkdoc opt">(</span>disp<span class="gtkdoc opt">,</span> root<span class="gtkdoc opt">,</span> <span class="number">0</span><span class="gtkdoc opt">,</span> <span class="number">0</span><span class="gtkdoc opt">,</span> <span class="number">320</span><span class="gtkdoc opt">,</span> <span class="number">240</span><span class="gtkdoc opt">,</span> <span class="number">0</span><span class="gtkdoc opt">,</span> <span class="number">0</span><span class="gtkdoc opt">,</span> <span class="number">0</span><span class="gtkdoc opt">);</span>

 <span class="function">XSetWindowBackgroundPixmap</span> <span class="gtkdoc opt">(</span>disp<span class="gtkdoc opt">,</span> win<span class="gtkdoc opt">,</span> None<span class="gtkdoc opt">);</span>

 <span class="function">XMapRaised</span> <span class="gtkdoc opt">(</span>disp<span class="gtkdoc opt">,</span> win<span class="gtkdoc opt">);</span>

 <span class="function">XSync</span> <span class="gtkdoc opt">(</span>disp<span class="gtkdoc opt">,</span> FALSE<span class="gtkdoc opt">);</span>

 <span class="function"><a href="GstVideoOverlay.html#gst-video-overlay-set-window-handle">gst_video_overlay_set_window_handle</a></span> <span class="gtkdoc opt">(</span><span class="function">GST_VIDEO_OVERLAY</span> <span class="gtkdoc opt">(</span><span class="function"><a href="../gstreamer-1.0/GstMessage.html#GST-MESSAGE-SRC:CAPS">GST_MESSAGE_SRC</a></span> <span class="gtkdoc opt">(</span>message<span class="gtkdoc opt">)),</span>
     win<span class="gtkdoc opt">);</span>

 <span class="function"><a href="../gstreamer-1.0/GstMessage.html#gst-message-unref">gst_message_unref</a></span> <span class="gtkdoc opt">(</span>message<span class="gtkdoc opt">);</span>

 <span class="keyword">return</span> GST_BUS_DROP<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc opt">...</span>
<span class="gtkdoc kwb">int</span>
<span class="function">main</span> <span class="gtkdoc opt">(</span><span class="gtkdoc kwb">int</span> argc<span class="gtkdoc opt">,</span> <span class="gtkdoc kwb">char</span> <span class="gtkdoc opt">**</span>argv<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
<span class="gtkdoc opt">...</span>
 bus <span class="gtkdoc opt">=</span> <span class="function"><a href="../gstreamer-1.0/GstPipeline.html#gst-pipeline-get-bus">gst_pipeline_get_bus</a></span> <span class="gtkdoc opt">(</span><span class="function">GST_PIPELINE</span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">));</span>
 <span class="function"><a href="../gstreamer-1.0/GstBus.html#gst-bus-set-sync-handler">gst_bus_set_sync_handler</a></span> <span class="gtkdoc opt">(</span>bus<span class="gtkdoc opt">, (</span>GstBusSyncHandler<span class="gtkdoc opt">)</span> create_window<span class="gtkdoc opt">,</span> pipeline<span class="gtkdoc opt">,</span>
        NULL<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">...</span>
<span class="gtkdoc opt">}</span></pre></td>
      </tr>
    </tbody>
  </table>
</div>

<p></p>
<div class="refsect3">
<a name="id-1.2.15.17.7.8"></a><h4>Two basic usage scenarios</h4>
<p>There are two basic usage scenarios: in the simplest case, the application
uses <span class="type">playbin</span> or <span class="type">plasink</span> or knows exactly what particular element is used
for video output, which is usually the case when the application creates
the videosink to use (e.g. <span class="type">xvimagesink</span>, <span class="type">ximagesink</span>, etc.) itself; in this
case, the application can just create the videosink element, create and
realize the window to render the video on and then
call <a class="link" href="GstVideoOverlay.html#gst-video-overlay-set-window-handle" title="gst_video_overlay_set_window_handle ()"><code class="function">gst_video_overlay_set_window_handle()</code></a> directly with the XID or native
window handle, before starting up the pipeline.
As <span class="type">playbin</span> and <span class="type">playsink</span> implement the video overlay interface and proxy
it transparently to the actual video sink even if it is created later, this
case also applies when using these elements.</p>
<p>In the other and more common case, the application does not know in advance
what GStreamer video sink element will be used for video output. This is
usually the case when an element such as <span class="type">autovideosink</span> is used.
In this case, the video sink element itself is created
asynchronously from a GStreamer streaming thread some time after the
pipeline has been started up. When that happens, however, the video sink
will need to know right then whether to render onto an already existing
application window or whether to create its own window. This is when it
posts a prepare-window-handle message, and that is also why this message needs
to be handled in a sync bus handler which will be called from the streaming
thread directly (because the video sink will need an answer right then).</p>
<p>As response to the prepare-window-handle element message in the bus sync
handler, the application may use <a class="link" href="GstVideoOverlay.html#gst-video-overlay-set-window-handle" title="gst_video_overlay_set_window_handle ()"><code class="function">gst_video_overlay_set_window_handle()</code></a> to tell
the video sink to render onto an existing window surface. At this point the
application should already have obtained the window handle / XID, so it
just needs to set it. It is generally not advisable to call any GUI toolkit
functions or window system functions from the streaming thread in which the
prepare-window-handle message is handled, because most GUI toolkits and
windowing systems are not thread-safe at all and a lot of care would be
required to co-ordinate the toolkit and window system calls of the
different threads (Gtk+ users please note: prior to Gtk+ 2.18
<code class="function">GDK_WINDOW_XID()</code> was just a simple structure access, so generally fine to do
within the bus sync handler; this macro was changed to a function call in
Gtk+ 2.18 and later, which is likely to cause problems when called from a
sync handler; see below for a better approach without <code class="function">GDK_WINDOW_XID()</code>
used in the callback).</p>
</div>
<div class="refsect3">
<a name="id-1.2.15.17.7.9"></a><h4>GstVideoOverlay and Gtk+</h4>
<div class="informalexample">
  <table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
    <tbody>
      <tr>
        <td class="listing_lines" align="right"><pre>1
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96</pre></td>
        <td class="listing_code"><pre class="programlisting"><span class="gtkdoc ppc">#include &lt;gst/video/videooverlay.h&gt;</span>
<span class="gtkdoc ppc">#include &lt;gtk/gtk.h&gt;</span>
<span class="gtkdoc ppc">#ifdef GDK_WINDOWING_X11</span>
<span class="gtkdoc ppc">#include &lt;gdk/gdkx.h&gt;</span>  <span class="gtkdoc slc">// for GDK_WINDOW_XID</span>
<span class="gtkdoc ppc"></span><span class="gtkdoc ppc">#endif</span>
<span class="gtkdoc ppc">#ifdef GDK_WINDOWING_WIN32</span>
<span class="gtkdoc ppc">#include &lt;gdk/gdkwin32.h&gt;</span>  <span class="gtkdoc slc">// for GDK_WINDOW_HWND</span>
<span class="gtkdoc ppc"></span><span class="gtkdoc ppc">#endif</span>
<span class="gtkdoc opt">...</span>
<span class="gtkdoc kwb">static</span> guintptr video_window_handle <span class="gtkdoc opt">=</span> <span class="number">0</span><span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">...</span>
<span class="gtkdoc kwb">static</span> GstBusSyncReply
<span class="function">bus_sync_handler</span> <span class="gtkdoc opt">(</span>GstBus <span class="gtkdoc opt">*</span> bus<span class="gtkdoc opt">,</span> GstMessage <span class="gtkdoc opt">*</span> message<span class="gtkdoc opt">,</span> gpointer user_data<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
 <span class="gtkdoc slc">// ignore anything but &apos;prepare-window-handle&apos; element messages</span>
 <span class="keyword">if</span> <span class="gtkdoc opt">(!</span><span class="function"><a href="GstVideoOverlay.html#gst-is-video-overlay-prepare-window-handle-message">gst_is_video_overlay_prepare_window_handle_message</a></span> <span class="gtkdoc opt">(</span>message<span class="gtkdoc opt">))</span>
   <span class="keyword">return</span> GST_BUS_PASS<span class="gtkdoc opt">;</span>

 <span class="keyword">if</span> <span class="gtkdoc opt">(</span>video_window_handle <span class="gtkdoc opt">!=</span> <span class="number">0</span><span class="gtkdoc opt">) {</span>
   GstVideoOverlay <span class="gtkdoc opt">*</span>overlay<span class="gtkdoc opt">;</span>

   <span class="gtkdoc slc">// GST_MESSAGE_SRC (message) will be the video sink element</span>
   overlay <span class="gtkdoc opt">=</span> <span class="function">GST_VIDEO_OVERLAY</span> <span class="gtkdoc opt">(</span><span class="function"><a href="../gstreamer-1.0/GstMessage.html#GST-MESSAGE-SRC:CAPS">GST_MESSAGE_SRC</a></span> <span class="gtkdoc opt">(</span>message<span class="gtkdoc opt">));</span>
   <span class="function"><a href="GstVideoOverlay.html#gst-video-overlay-set-window-handle">gst_video_overlay_set_window_handle</a></span> <span class="gtkdoc opt">(</span>overlay<span class="gtkdoc opt">,</span> video_window_handle<span class="gtkdoc opt">);</span>
 <span class="gtkdoc opt">}</span> <span class="keyword">else</span> <span class="gtkdoc opt">{</span>
   <span class="function"><a href="../glib/glib-Message-Logging.html#g-warning">g_warning</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;Should have obtained video_window_handle by now!&quot;</span><span class="gtkdoc opt">);</span>
 <span class="gtkdoc opt">}</span>

 <span class="function"><a href="../gstreamer-1.0/GstMessage.html#gst-message-unref">gst_message_unref</a></span> <span class="gtkdoc opt">(</span>message<span class="gtkdoc opt">);</span>
 <span class="keyword">return</span> GST_BUS_DROP<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc opt">...</span>
<span class="gtkdoc kwb">static void</span>
<span class="function">video_widget_realize_cb</span> <span class="gtkdoc opt">(</span>GtkWidget <span class="gtkdoc opt">*</span> widget<span class="gtkdoc opt">,</span> gpointer data<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
<span class="gtkdoc ppc">#if GTK_CHECK_VERSION(2,18,0)</span>
  <span class="gtkdoc slc">// Tell Gtk+/Gdk to create a native window for this widget instead of</span>
  <span class="gtkdoc slc">// drawing onto the parent widget.</span>
  <span class="gtkdoc slc">// This is here just for pedagogical purposes, GDK_WINDOW_XID will call</span>
  <span class="gtkdoc slc">// it as well in newer Gtk versions</span>
  <span class="keyword">if</span> <span class="gtkdoc opt">(!</span><span class="function">gdk_window_ensure_native</span> <span class="gtkdoc opt">(</span>widget<span class="gtkdoc opt">-&gt;</span>window<span class="gtkdoc opt">))</span>
    <span class="function"><a href="../glib/glib-Message-Logging.html#g-error">g_error</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;Couldn&apos;t create native window needed for GstVideoOverlay!&quot;</span><span class="gtkdoc opt">);</span>
<span class="gtkdoc ppc">#endif</span>

<span class="gtkdoc ppc">#ifdef GDK_WINDOWING_X11</span>
  <span class="gtkdoc opt">{</span>
    gulong xid <span class="gtkdoc opt">=</span> <span class="function">GDK_WINDOW_XID</span> <span class="gtkdoc opt">(</span><span class="function">gtk_widget_get_window</span> <span class="gtkdoc opt">(</span>video_window<span class="gtkdoc opt">));</span>
    video_window_handle <span class="gtkdoc opt">=</span> xid<span class="gtkdoc opt">;</span>
  <span class="gtkdoc opt">}</span>
<span class="gtkdoc ppc">#endif</span>
<span class="gtkdoc ppc">#ifdef GDK_WINDOWING_WIN32</span>
  <span class="gtkdoc opt">{</span>
    HWND wnd <span class="gtkdoc opt">=</span> <span class="function">GDK_WINDOW_HWND</span> <span class="gtkdoc opt">(</span><span class="function">gtk_widget_get_window</span> <span class="gtkdoc opt">(</span>video_window<span class="gtkdoc opt">));</span>
    video_window_handle <span class="gtkdoc opt">= (</span>guintptr<span class="gtkdoc opt">)</span> wnd<span class="gtkdoc opt">;</span>
  <span class="gtkdoc opt">}</span>
<span class="gtkdoc ppc">#endif</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc opt">...</span>
<span class="gtkdoc kwb">int</span>
<span class="function">main</span> <span class="gtkdoc opt">(</span><span class="gtkdoc kwb">int</span> argc<span class="gtkdoc opt">,</span> <span class="gtkdoc kwb">char</span> <span class="gtkdoc opt">**</span>argv<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
  GtkWidget <span class="gtkdoc opt">*</span>video_window<span class="gtkdoc opt">;</span>
  GtkWidget <span class="gtkdoc opt">*</span>app_window<span class="gtkdoc opt">;</span>
  <span class="gtkdoc opt">...</span>
  app_window <span class="gtkdoc opt">=</span> <span class="function">gtk_window_new</span> <span class="gtkdoc opt">(</span>GTK_WINDOW_TOPLEVEL<span class="gtkdoc opt">);</span>
  <span class="gtkdoc opt">...</span>
  video_window <span class="gtkdoc opt">=</span> <span class="function">gtk_drawing_area_new</span> <span class="gtkdoc opt">();</span>
  <span class="function"><a href="../gobject/gobject-Signals.html#g-signal-connect">g_signal_connect</a></span> <span class="gtkdoc opt">(</span>video_window<span class="gtkdoc opt">,</span> <span class="string">&quot;realize&quot;</span><span class="gtkdoc opt">,</span>
      <span class="function"><a href="../gobject/gobject-Closures.html#G-CALLBACK:CAPS">G_CALLBACK</a></span> <span class="gtkdoc opt">(</span>video_widget_realize_cb<span class="gtkdoc opt">),</span> NULL<span class="gtkdoc opt">);</span>
  <span class="function">gtk_widget_set_double_buffered</span> <span class="gtkdoc opt">(</span>video_window<span class="gtkdoc opt">,</span> FALSE<span class="gtkdoc opt">);</span>
  <span class="gtkdoc opt">...</span>
  <span class="gtkdoc slc">// usually the video_window will not be directly embedded into the</span>
  <span class="gtkdoc slc">// application window like this, but there will be many other widgets</span>
  <span class="gtkdoc slc">// and the video window will be embedded in one of them instead</span>
  <span class="function">gtk_container_add</span> <span class="gtkdoc opt">(</span><span class="function">GTK_CONTAINER</span> <span class="gtkdoc opt">(</span>ap_window<span class="gtkdoc opt">),</span> video_window<span class="gtkdoc opt">);</span>
  <span class="gtkdoc opt">...</span>
  <span class="gtkdoc slc">// show the GUI</span>
  <span class="function">gtk_widget_show_all</span> <span class="gtkdoc opt">(</span>app_window<span class="gtkdoc opt">);</span>

  <span class="gtkdoc slc">// realize window now so that the video window gets created and we can</span>
  <span class="gtkdoc slc">// obtain its XID/HWND before the pipeline is started up and the videosink</span>
  <span class="gtkdoc slc">// asks for the XID/HWND of the window to render onto</span>
  <span class="function">gtk_widget_realize</span> <span class="gtkdoc opt">(</span>video_window<span class="gtkdoc opt">);</span>

  <span class="gtkdoc slc">// we should have the XID/HWND now</span>
  <span class="function"><a href="../glib/glib-Testing.html#g-assert">g_assert</a></span> <span class="gtkdoc opt">(</span>video_window_handle <span class="gtkdoc opt">!=</span> <span class="number">0</span><span class="gtkdoc opt">);</span>
  <span class="gtkdoc opt">...</span>
  <span class="gtkdoc slc">// set up sync handler for setting the xid once the pipeline is started</span>
  bus <span class="gtkdoc opt">=</span> <span class="function"><a href="../gstreamer-1.0/GstPipeline.html#gst-pipeline-get-bus">gst_pipeline_get_bus</a></span> <span class="gtkdoc opt">(</span><span class="function">GST_PIPELINE</span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">));</span>
  <span class="function"><a href="../gstreamer-1.0/GstBus.html#gst-bus-set-sync-handler">gst_bus_set_sync_handler</a></span> <span class="gtkdoc opt">(</span>bus<span class="gtkdoc opt">, (</span>GstBusSyncHandler<span class="gtkdoc opt">)</span> bus_sync_handler<span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">,</span>
      NULL<span class="gtkdoc opt">);</span>
  <span class="function"><a href="../gstreamer-1.0/GstObject.html#gst-object-unref">gst_object_unref</a></span> <span class="gtkdoc opt">(</span>bus<span class="gtkdoc opt">);</span>
  <span class="gtkdoc opt">...</span>
  <span class="function"><a href="../gstreamer-1.0/GstElement.html#gst-element-set-state">gst_element_set_state</a></span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">,</span> GST_STATE_PLAYING<span class="gtkdoc opt">);</span>
  <span class="gtkdoc opt">...</span>
<span class="gtkdoc opt">}</span></pre></td>
      </tr>
    </tbody>
  </table>
</div>

<p></p>
</div>
<div class="refsect3">
<a name="id-1.2.15.17.7.10"></a><h4>GstVideoOverlay and Qt</h4>
<div class="informalexample">
  <table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
    <tbody>
      <tr>
        <td class="listing_lines" align="right"><pre>1
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53</pre></td>
        <td class="listing_code"><pre class="programlisting"><span class="gtkdoc ppc">#include &lt;glib.h&gt;</span>
<span class="gtkdoc ppc">#include &lt;gst/gst.h&gt;</span>
<span class="gtkdoc ppc">#include &lt;gst/video/videooverlay.h&gt;</span>

<span class="gtkdoc ppc">#include &lt;QApplication&gt;</span>
<span class="gtkdoc ppc">#include &lt;QTimer&gt;</span>
<span class="gtkdoc ppc">#include &lt;QWidget&gt;</span>

<span class="gtkdoc kwb">int</span> <span class="function">main</span><span class="gtkdoc opt">(</span><span class="gtkdoc kwb">int</span> argc<span class="gtkdoc opt">,</span> <span class="gtkdoc kwb">char</span> <span class="gtkdoc opt">*</span>argv<span class="gtkdoc opt">[])</span>
<span class="gtkdoc opt">{</span>
  <span class="keyword">if</span> <span class="gtkdoc opt">(!</span><span class="function"><a href="../glib/glib-Deprecated-Thread-APIs.html#g-thread-supported">g_thread_supported</a></span> <span class="gtkdoc opt">())</span>
    <span class="function"><a href="../glib/glib-Deprecated-Thread-APIs.html#g-thread-init">g_thread_init</a></span> <span class="gtkdoc opt">(</span>NULL<span class="gtkdoc opt">);</span>

  <span class="function"><a href="../gstreamer-1.0/gstreamer-Gst.html#gst-init">gst_init</a></span> <span class="gtkdoc opt">(&amp;</span>argc<span class="gtkdoc opt">, &amp;</span>argv<span class="gtkdoc opt">);</span>
  QApplication <span class="function">app</span><span class="gtkdoc opt">(</span>argc<span class="gtkdoc opt">,</span> argv<span class="gtkdoc opt">);</span>
  app<span class="gtkdoc opt">.</span><span class="function">connect</span><span class="gtkdoc opt">(&amp;</span>app<span class="gtkdoc opt">,</span> <span class="function">SIGNAL</span><span class="gtkdoc opt">(</span><span class="function">lastWindowClosed</span><span class="gtkdoc opt">()), &amp;</span>app<span class="gtkdoc opt">,</span> <span class="function">SLOT</span><span class="gtkdoc opt">(</span><span class="function">quit</span> <span class="gtkdoc opt">()));</span>

  <span class="gtkdoc slc">// prepare the pipeline</span>

  GstElement <span class="gtkdoc opt">*</span>pipeline <span class="gtkdoc opt">=</span> <span class="function"><a href="../gstreamer-1.0/GstPipeline.html#gst-pipeline-new">gst_pipeline_new</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;xvoverlay&quot;</span><span class="gtkdoc opt">);</span>
  GstElement <span class="gtkdoc opt">*</span>src <span class="gtkdoc opt">=</span> <span class="function"><a href="../gstreamer-1.0/GstElementFactory.html#gst-element-factory-make">gst_element_factory_make</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;videotestsrc&quot;</span><span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
  GstElement <span class="gtkdoc opt">*</span>sink <span class="gtkdoc opt">=</span> <span class="function"><a href="../gstreamer-1.0/GstElementFactory.html#gst-element-factory-make">gst_element_factory_make</a></span> <span class="gtkdoc opt">(</span><span class="string">&quot;xvimagesink&quot;</span><span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
  <span class="function"><a href="../gstreamer-1.0/GstBin.html#gst-bin-add-many">gst_bin_add_many</a></span> <span class="gtkdoc opt">(</span><span class="function">GST_BIN</span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">),</span> src<span class="gtkdoc opt">,</span> sink<span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">);</span>
  <span class="function"><a href="../gstreamer-1.0/GstElement.html#gst-element-link">gst_element_link</a></span> <span class="gtkdoc opt">(</span>src<span class="gtkdoc opt">,</span> sink<span class="gtkdoc opt">);</span>

  <span class="gtkdoc slc">// prepare the ui</span>

  QWidget window<span class="gtkdoc opt">;</span>
  window<span class="gtkdoc opt">.</span><span class="function">resize</span><span class="gtkdoc opt">(</span><span class="number">320</span><span class="gtkdoc opt">,</span> <span class="number">240</span><span class="gtkdoc opt">);</span>
  window<span class="gtkdoc opt">.</span><span class="function">show</span><span class="gtkdoc opt">();</span>

  WId xwinid <span class="gtkdoc opt">=</span> window<span class="gtkdoc opt">.</span><span class="function">winId</span><span class="gtkdoc opt">();</span>
  <span class="function"><a href="GstVideoOverlay.html#gst-video-overlay-set-window-handle">gst_video_overlay_set_window_handle</a></span> <span class="gtkdoc opt">(</span><span class="function">GST_VIDEO_OVERLAY</span> <span class="gtkdoc opt">(</span>sink<span class="gtkdoc opt">),</span> xwinid<span class="gtkdoc opt">);</span>

  <span class="gtkdoc slc">// run the pipeline</span>

  GstStateChangeReturn sret <span class="gtkdoc opt">=</span> <span class="function"><a href="../gstreamer-1.0/GstElement.html#gst-element-set-state">gst_element_set_state</a></span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">,</span>
      GST_STATE_PLAYING<span class="gtkdoc opt">);</span>
  <span class="keyword">if</span> <span class="gtkdoc opt">(</span>sret <span class="gtkdoc opt">==</span> GST_STATE_CHANGE_FAILURE<span class="gtkdoc opt">) {</span>
    <span class="function"><a href="../gstreamer-1.0/GstElement.html#gst-element-set-state">gst_element_set_state</a></span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">,</span> GST_STATE_NULL<span class="gtkdoc opt">);</span>
    <span class="function"><a href="../gstreamer-1.0/GstObject.html#gst-object-unref">gst_object_unref</a></span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">);</span>
    <span class="gtkdoc slc">// Exit application</span>
    <span class="gtkdoc kwc">QTimer</span><span class="gtkdoc opt">::</span><span class="function">singleShot</span><span class="gtkdoc opt">(</span><span class="number">0</span><span class="gtkdoc opt">,</span> <span class="gtkdoc kwc">QApplication</span><span class="gtkdoc opt">::</span><span class="function">activeWindow</span><span class="gtkdoc opt">(),</span> <span class="function">SLOT</span><span class="gtkdoc opt">(</span><span class="function">quit</span><span class="gtkdoc opt">()));</span>
  <span class="gtkdoc opt">}</span>

  <span class="gtkdoc kwb">int</span> ret <span class="gtkdoc opt">=</span> app<span class="gtkdoc opt">.</span><span class="function">exec</span><span class="gtkdoc opt">();</span>

  window<span class="gtkdoc opt">.</span><span class="function">hide</span><span class="gtkdoc opt">();</span>
  <span class="function"><a href="../gstreamer-1.0/GstElement.html#gst-element-set-state">gst_element_set_state</a></span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">,</span> GST_STATE_NULL<span class="gtkdoc opt">);</span>
  <span class="function"><a href="../gstreamer-1.0/GstObject.html#gst-object-unref">gst_object_unref</a></span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">);</span>

  <span class="keyword">return</span> ret<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span></pre></td>
      </tr>
    </tbody>
  </table>
</div>

<p></p>
</div>
</div>
<div class="refsect1">
<a name="GstVideoOverlay.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="gst-video-overlay-got-window-handle"></a><h3>gst_video_overlay_got_window_handle ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_video_overlay_got_window_handle (<em class="parameter"><code><a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> *overlay</code></em>,
                                     <em class="parameter"><code><a href="../glib/glib-Basic-Types.html#guintptr"><span class="type">guintptr</span></a> handle</code></em>);</pre>
<p>This will post a "have-window-handle" element message on the bus.</p>
<p>This function should only be used by video overlay plugin developers.</p>
<div class="refsect3">
<a name="gst-video-overlay-got-window-handle.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>overlay</p></td>
<td class="parameter_description"><p>a <a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> which got a window</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>handle</p></td>
<td class="parameter_description"><p>a platform-specific handle referencing the window</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-overlay-set-window-handle"></a><h3>gst_video_overlay_set_window_handle ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_video_overlay_set_window_handle (<em class="parameter"><code><a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> *overlay</code></em>,
                                     <em class="parameter"><code><a href="../glib/glib-Basic-Types.html#guintptr"><span class="type">guintptr</span></a> handle</code></em>);</pre>
<p>This will call the video overlay's set_window_handle method. You
should use this method to tell to an overlay to display video output to a
specific window (e.g. an XWindow on X11). Passing 0 as the  <em class="parameter"><code>handle</code></em>
 will
tell the overlay to stop using that window and create an internal one.</p>
<div class="refsect3">
<a name="gst-video-overlay-set-window-handle.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>overlay</p></td>
<td class="parameter_description"><p>a <a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> to set the window on.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>handle</p></td>
<td class="parameter_description"><p>a handle referencing the window.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-overlay-prepare-window-handle"></a><h3>gst_video_overlay_prepare_window_handle ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_video_overlay_prepare_window_handle
                               (<em class="parameter"><code><a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> *overlay</code></em>);</pre>
<p>This will post a "prepare-window-handle" element message on the bus
to give applications an opportunity to call
<a class="link" href="GstVideoOverlay.html#gst-video-overlay-set-window-handle" title="gst_video_overlay_set_window_handle ()"><code class="function">gst_video_overlay_set_window_handle()</code></a> before a plugin creates its own
window.</p>
<p>This function should only be used by video overlay plugin developers.</p>
<div class="refsect3">
<a name="gst-video-overlay-prepare-window-handle.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>overlay</p></td>
<td class="parameter_description"><p>a <a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> which does not yet have an Window handle set</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-overlay-expose"></a><h3>gst_video_overlay_expose ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_video_overlay_expose (<em class="parameter"><code><a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> *overlay</code></em>);</pre>
<p>Tell an overlay that it has been exposed. This will redraw the current frame
in the drawable even if the pipeline is PAUSED.</p>
<div class="refsect3">
<a name="gst-video-overlay-expose.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>overlay</p></td>
<td class="parameter_description"><p>a <a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> to expose.</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-overlay-handle-events"></a><h3>gst_video_overlay_handle_events ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_video_overlay_handle_events (<em class="parameter"><code><a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> *overlay</code></em>,
                                 <em class="parameter"><code><a href="../glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> handle_events</code></em>);</pre>
<p>Tell an overlay that it should handle events from the window system. These
events are forwarded 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 <a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a>.</p>
<div class="refsect3">
<a name="gst-video-overlay-handle-events.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>overlay</p></td>
<td class="parameter_description"><p>a <a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> to expose.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>handle_events</p></td>
<td class="parameter_description"><p>a <a href="../glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> indicating if events should be handled or not.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-overlay-set-render-rectangle"></a><h3>gst_video_overlay_set_render_rectangle ()</h3>
<pre class="programlisting"><a href="../glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
gst_video_overlay_set_render_rectangle
                               (<em class="parameter"><code><a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> *overlay</code></em>,
                                <em class="parameter"><code><a href="../glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> x</code></em>,
                                <em class="parameter"><code><a href="../glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> y</code></em>,
                                <em class="parameter"><code><a href="../glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> width</code></em>,
                                <em class="parameter"><code><a href="../glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> height</code></em>);</pre>
<p>Configure a subregion as a video target within the window set by
<a class="link" href="GstVideoOverlay.html#gst-video-overlay-set-window-handle" title="gst_video_overlay_set_window_handle ()"><code class="function">gst_video_overlay_set_window_handle()</code></a>. If this is not used or not supported
the video will fill the area of the window set as the overlay to 100%.
By specifying the rectangle, the video can be overlayed to a specific region
of that window only. After setting the new rectangle one should call
<a class="link" href="GstVideoOverlay.html#gst-video-overlay-expose" title="gst_video_overlay_expose ()"><code class="function">gst_video_overlay_expose()</code></a> to force a redraw. To unset the region pass -1 for
the <em class="parameter"><code>width</code></em>
 and <em class="parameter"><code>height</code></em>
 parameters.</p>
<p>This method is needed for non fullscreen video overlay in UI toolkits that
do not support subwindows.</p>
<div class="refsect3">
<a name="gst-video-overlay-set-render-rectangle.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>overlay</p></td>
<td class="parameter_description"><p>a <a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>x</p></td>
<td class="parameter_description"><p>the horizontal offset of the render area inside the window</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>y</p></td>
<td class="parameter_description"><p>the vertical offset of the render area inside the window</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>width</p></td>
<td class="parameter_description"><p>the width of the render area inside the window</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>height</p></td>
<td class="parameter_description"><p>the height of the render area inside the window</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gst-video-overlay-set-render-rectangle.returns"></a><h4>Returns</h4>
<p> <a href="../glib/glib-Standard-Macros.html#FALSE:CAPS"><code class="literal">FALSE</code></a> if not supported by the sink.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-is-video-overlay-prepare-window-handle-message"></a><h3>gst_is_video_overlay_prepare_window_handle_message ()</h3>
<pre class="programlisting"><a href="../glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
gst_is_video_overlay_prepare_window_handle_message
                               (<em class="parameter"><code><a href="../gstreamer-1.0/GstMessage.html#GstMessage-struct"><span class="type">GstMessage</span></a> *msg</code></em>);</pre>
<p>Convenience function to check if the given message is a
"prepare-window-handle" message from a <a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a>.</p>
<div class="refsect3">
<a name="gst-is-video-overlay-prepare-window-handle-message.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>msg</p></td>
<td class="parameter_description"><p>a <a href="../gstreamer-1.0/GstMessage.html#GstMessage-struct"><span class="type">GstMessage</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gst-is-video-overlay-prepare-window-handle-message.returns"></a><h4>Returns</h4>
<p> whether <em class="parameter"><code>msg</code></em>
is a "prepare-window-handle" message</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-overlay-install-properties"></a><h3>gst_video_overlay_install_properties ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_video_overlay_install_properties (<em class="parameter"><code><a href="../gobject/gobject-The-Base-Object-Type.html#GObjectClass"><span class="type">GObjectClass</span></a> *oclass</code></em>,
                                      <em class="parameter"><code><a href="../glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> last_prop_id</code></em>);</pre>
<p>This helper shall be used by classes implementing the <a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a>
interface that want the render rectangle to be controllable using
properties. This helper will install "render-rectangle" property into the
class.</p>
<p>Since 1.14</p>
<div class="refsect3">
<a name="gst-video-overlay-install-properties.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>oclass</p></td>
<td class="parameter_description"><p>The class on which the properties will be installed</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>last_prop_id</p></td>
<td class="parameter_description"><p>The first free property ID to use</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-overlay-set-property"></a><h3>gst_video_overlay_set_property ()</h3>
<pre class="programlisting"><a href="../glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
gst_video_overlay_set_property (<em class="parameter"><code><a href="../gobject/gobject-The-Base-Object-Type.html#GObject-struct"><span class="type">GObject</span></a> *object</code></em>,
                                <em class="parameter"><code><a href="../glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> last_prop_id</code></em>,
                                <em class="parameter"><code><a href="../glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> property_id</code></em>,
                                <em class="parameter"><code>const <a href="../gobject/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> *value</code></em>);</pre>
<p>This helper shall be used by classes implementing the <a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a>
interface that want the render rectangle to be controllable using
properties. This helper will parse and set the render rectangle calling
<a class="link" href="GstVideoOverlay.html#gst-video-overlay-set-render-rectangle" title="gst_video_overlay_set_render_rectangle ()"><code class="function">gst_video_overlay_set_render_rectangle()</code></a>.</p>
<div class="refsect3">
<a name="gst-video-overlay-set-property.parameters"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>object</p></td>
<td class="parameter_description"><p>The instance on which the property is set</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>last_prop_id</p></td>
<td class="parameter_description"><p>The highest property ID.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>property_id</p></td>
<td class="parameter_description"><p>The property ID</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>value</p></td>
<td class="parameter_description"><p>The <a href="../gobject/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> to be set</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="gst-video-overlay-set-property.returns"></a><h4>Returns</h4>
<p> <a href="../glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if the <em class="parameter"><code>property_id</code></em>
matches the GstVideoOverlay property</p>
<p>Since 1.14</p>
</div>
</div>
</div>
<div class="refsect1">
<a name="GstVideoOverlay.other_details"></a><h2>Types and Values</h2>
<div class="refsect2">
<a name="GstVideoOverlay-struct"></a><h3>GstVideoOverlay</h3>
<pre class="programlisting">typedef struct _GstVideoOverlay GstVideoOverlay;</pre>
<p>Opaque <a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> interface structure</p>
</div>
<hr>
<div class="refsect2">
<a name="GstVideoOverlayInterface"></a><h3>struct GstVideoOverlayInterface</h3>
<pre class="programlisting">struct GstVideoOverlayInterface {
  GTypeInterface iface;

  /* virtual functions */
  void (*expose)               (GstVideoOverlay *overlay);

  void (*handle_events)        (GstVideoOverlay *overlay, gboolean handle_events);

  void (*set_render_rectangle) (GstVideoOverlay *overlay,
                                gint x, gint y,
                                gint width, gint height);

  void (*set_window_handle)    (GstVideoOverlay *overlay, guintptr handle);
};
</pre>
<p><a class="link" href="GstVideoOverlay.html" title="GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> interface</p>
<div class="refsect3">
<a name="GstVideoOverlayInterface.members"></a><h4>Members</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="300px" class="struct_members_name">
<col class="struct_members_description">
<col width="200px" class="struct_members_annotations">
</colgroup>
<tbody>
<tr>
<td class="struct_member_name"><p><a href="../gobject/gobject-Type-Information.html#GTypeInterface"><span class="type">GTypeInterface</span></a> <em class="structfield"><code><a name="GstVideoOverlayInterface.iface"></a>iface</code></em>;</p></td>
<td class="struct_member_description"><p>parent interface type.</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="GstVideoOverlayInterface.expose"></a>expose</code></em> ()</p></td>
<td class="struct_member_description"><p>virtual method to handle expose events</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="GstVideoOverlayInterface.handle-events"></a>handle_events</code></em> ()</p></td>
<td class="struct_member_description"><p>virtual method to handle events</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="GstVideoOverlayInterface.set-render-rectangle"></a>set_render_rectangle</code></em> ()</p></td>
<td class="struct_member_description"><p>virtual method to set the render rectangle</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="GstVideoOverlayInterface.set-window-handle"></a>set_window_handle</code></em> ()</p></td>
<td class="struct_member_description"><p>virtual method to configure the window handle</p></td>
<td class="struct_member_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
</div>
</div>
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