videosink = gst_element_factory_make ("xvimagesink", "videosink");
if ( !GST_IS_OBJECT(videosink) )
videosink = gst_element_factory_make ("ximagesink", "videosink");
videosink = gst_element_factory_make ("xvimagesink", "videosink");
if ( !GST_IS_OBJECT(videosink) )
videosink = gst_element_factory_make ("ximagesink", "videosink");