Hello, I suffer strange problem when using xvimagesink and ximagesink and displaying the output to Qt4's QWidget. I initialize sink element with windowid of QWidget: gst_x_overlay_set_xwindow_id ((GstXOverlay*)xvimagesink, ui->video->winId()); and then play video to it using playbin with this sink set as video-sink: g_object_set(G_OBJECT (_pipeline), "video-sink", xvimagesink, NULL); Video files (I tried avi with Xvid encoded video) are played just fine, but when I try to play any DVD disc pipeline works ok, sound goes but nothing is displayed on the widget and console is filled with X Error messages: X Error: BadGC (invalid GC parameter) 13 Extension: 133 (Uknown extension) Minor opcode: 19 (Unknown request) Resource id: 0x4c00002 I think it prints one such text on every frame, very often. Also, if I set windowid of the main window of application, i.e.: gst_x_overlay_set_xwindow_id ((GstXOverlay*)xvimagesink, this->winId()); everything works ok, too. Could you please help me with the problem? How can I fix it or maybe it's a bug in GStreamer or Qt?