Instead of always using xvimagesink as GStreamer backend for the
widget and window control (works only with X11), we now try to
pick a video sink that fits the current configuration.
It first tries a set of known video sinks that can work with
the Qt platform plugin in use. If none is available, it
dynamically picks a video sink available on the system that can be
used with our backend.
Even if the video sink is now picked in a smarter way, xcb is still
the only supported platform plugin. The reason is that it's the
only Unix plugin which can provide a valid native window handle.
Additional work is needed to support other plugins like wayland
or directfb.
Change-Id: I3843dea363d6a0b85a6cc1f2952783b743e48ac6
Reviewed-by: Christian Stromme <christian.stromme@theqtcompany.com>
cd3d540522