QT5.2.0运行自带的camera程序时出现以下错误：（centos 6.4）不知如何解决
(<unknown>:4810): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(<unknown>:4810): GLib-GObject-CRITICAL **: g_signal_connect_data: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(<unknown>:4810): GStreamer-CRITICAL **: gst_object_ref: assertion `object != NULL' failed
(<unknown>:4810): GStreamer-CRITICAL **: gst_object_sink: assertion `GST_IS_OBJECT (object)' failed
(<unknown>:4810): GStreamer-CRITICAL **: gst_element_get_bus: assertion `GST_IS_ELEMENT (element)' failed
(<unknown>:4810): GStreamer-CRITICAL **: gst_bus_add_watch_full: assertion `GST_IS_BUS (bus)' failed
(<unknown>:4810): GStreamer-CRITICAL **: gst_bus_set_sync_handler: assertion `GST_IS_BUS (bus)' failed
(<unknown>:4810): GStreamer-CRITICAL **: gst_object_ref: assertion `object != NULL' failed
/home/ymym/Qt5.2.0/5.2.0/gcc_64/examples/multimediawidgets/build-camera-Desktop_Qt_5_2_0_GCC_64bit-Debug/camera: symbol lookup error: /home/ymym/Qt5.2.0/5.2.0/gcc_64/plugins/mediaservice/../../lib/libqgsttools_p.so.1: undefined symbol:
gst_element_factory_list_get_elements
