How to display GStreamer video in my own Gtk::Window?

Hi!

How can I display GStreamer video in an Gtk::Window that I created on my
own?

I haven’t found any example in Ruby, so I’m trying to port this:
https://svn.sat.qc.ca/trac/miville/browser/inhouse/prototypes/gstreamer/cpp/fullscreen/test.c?rev=1235

To connect the stream to the Window, that example does:
gst_x_overlay_set_xwindow_id(GST_X_OVERLAY(data),
GDK_WINDOW_XWINDOW(widget->window));

However, I can’t find any references to X Overlays in the Gst
documentation at
http://ruby-gnome2.sourceforge.jp/hiki.cgi?Ruby%2FGStreamer .

So what do I need to do to display GStreamer video in my own window?

Regards //Johan