Created attachment 373057 [details]
Gtk on Windows 10

It seems that there's a bug in d3dvideosink when setting render rectangle.

I have modified
https://github.com/GStreamer/gstreamer-sharp/blob/master/samples/BasicTutorial5.cs
to set the render rectangle, like this:

            VideoOverlayAdapter adapter = new
VideoOverlayAdapter(overlay.Handle);
            adapter.WindowHandle = windowHandle;
            adapter.SetRenderRectangle(50, 50, 427, 240);
            adapter.HandleEvents(true);

I expected that the video will be rendered in the 427x240 rectangle, at the
position 50,50, but there is a correct rectangle at the position, and video
is moved to the 50,50 inside this rectangle. The same happens in the
WinForms version of the sample.

It looks OK when running on Linux Mint 19.