ffi::gst_rtsp_media_factory_add_role(factory.to_glib_none().0,
                                             "user".to_glib_none().0,
                                             RTSP_PERM_MEDIA_FACTORY_ACCESS.to_glib_none().0,
                                             <bool as StaticType>::static_type().to_glib() as *const u8,
                                             true.to_glib() as *const u8,
                                             RTSP_PERM_MEDIA_FACTORY_CONSTRUCT.as_ptr() as *const u8,
                                             <bool as StaticType>::static_type().to_glib() as *const u8,
                                             true.to_glib() as *const u8,
                                             ptr::null_mut::<u8>());