/libQt5WebKit.so: undefined reference to `gst_x_overlay_set_window

hi to all,
I've centos6.6(x86) and qt5.3.2. I am porting a program
form qt4 to qt5. and having this problem ( compiler output ) :-
Code:
5:20:29: Running steps for project clipgrab...
15:20:29: Configuration unchanged, skipping qmake step.
15:20:29: Starting: "/usr/bin/make" 
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -fPIE -DCLIPGRAB_VERSION=3.5.6 -DQT_NO_DEBUG -DQT_WEBKITWIDGETS_LIB -DQT_WEBKIT_LIB -DQT_WIDGETS_LIB -DQT_XML_LIB -DQT_NETWORK_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../../Qt5.3.2/5.3/gcc/mkspecs/linux-g++ -I. -I. -I../../Qt5.3.2/5.3/gcc/include -I../../Qt5.3.2/5.3/gcc/include/QtWebKitWidgets -I../../Qt5.3.2/5.3/gcc/include/QtWebKit -I../../Qt5.3.2/5.3/gcc/include/QtWidgets -I../../Qt5.3.2/5.3/gcc/include/QtXml -I../../Qt5.3.2/5.3/gcc/include/QtNetwork -I../../Qt5.3.2/5.3/gcc/include/QtGui -I../../Qt5.3.2/5.3/gcc/include/QtCore -I. -I. -o main.o main.cpp
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -fPIE -DCLIPGRAB_VERSION=3.5.6 -DQT_NO_DEBUG -DQT_WEBKITWIDGETS_LIB -DQT_WEBKIT_LIB -DQT_WIDGETS_LIB -DQT_XML_LIB -DQT_NETWORK_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../../Qt5.3.2/5.3/gcc/mkspecs/linux-g++ -I. -I. -I../../Qt5.3.2/5.3/gcc/include -I../../Qt5.3.2/5.3/gcc/include/QtWebKitWidgets -I../../Qt5.3.2/5.3/gcc/include/QtWebKit -I../../Qt5.3.2/5.3/gcc/include/QtWidgets -I../../Qt5.3.2/5.3/gcc/include/QtXml -I../../Qt5.3.2/5.3/gcc/include/QtNetwork -I../../Qt5.3.2/5.3/gcc/include/QtGui -I../../Qt5.3.2/5.3/gcc/include/QtCore -I. -I. -o mainwindow.o mainwindow.cpp
mainwindow.cpp: In member function 'void MainWindow::on_downloadTree_customContextMenuRequested(const QPoint&)':
mainwindow.cpp:817:22: warning: unused variable 'item' [-Wunused-variable]
     QTreeWidgetItem* item = ui.downloadTree->itemAt(pos);
                      ^
/opt/Qt5.3.2/5.3/gcc/bin/moc -DCLIPGRAB_VERSION=3.5.6 -DQT_NO_DEBUG -DQT_WEBKITWIDGETS_LIB -DQT_WEBKIT_LIB -DQT_WIDGETS_LIB -DQT_XML_LIB -DQT_NETWORK_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I/opt/Qt5.3.2/5.3/gcc/mkspecs/linux-g++ -I/opt/software/clipgrab-3.5.6 -I/opt/software/clipgrab-3.5.6 -I/opt/Qt5.3.2/5.3/gcc/include -I/opt/Qt5.3.2/5.3/gcc/include/QtWebKitWidgets -I/opt/Qt5.3.2/5.3/gcc/include/QtWebKit -I/opt/Qt5.3.2/5.3/gcc/include/QtWidgets -I/opt/Qt5.3.2/5.3/gcc/include/QtXml -I/opt/Qt5.3.2/5.3/gcc/include/QtNetwork -I/opt/Qt5.3.2/5.3/gcc/include/QtGui -I/opt/Qt5.3.2/5.3/gcc/include/QtCore mainwindow.h -o moc_mainwindow.cpp
g++ -c -pipe -O2 -Wall -W -D_REENTRANT -fPIE -DCLIPGRAB_VERSION=3.5.6 -DQT_NO_DEBUG -DQT_WEBKITWIDGETS_LIB -DQT_WEBKIT_LIB -DQT_WIDGETS_LIB -DQT_XML_LIB -DQT_NETWORK_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../../Qt5.3.2/5.3/gcc/mkspecs/linux-g++ -I. -I. -I../../Qt5.3.2/5.3/gcc/include -I../../Qt5.3.2/5.3/gcc/include/QtWebKitWidgets -I../../Qt5.3.2/5.3/gcc/include/QtWebKit -I../../Qt5.3.2/5.3/gcc/include/QtWidgets -I../../Qt5.3.2/5.3/gcc/include/QtXml -I../../Qt5.3.2/5.3/gcc/include/QtNetwork -I../../Qt5.3.2/5.3/gcc/include/QtGui -I../../Qt5.3.2/5.3/gcc/include/QtCore -I. -I. -o moc_mainwindow.o moc_mainwindow.cpp
g++ -Wl,-O1 -Wl,-rpath,/opt/Qt5.3.2/5.3/gcc -Wl,-rpath,/opt/Qt5.3.2/5.3/gcc/lib -Wl,-rpath-link,/opt/Qt5.3.2/5.3/gcc/lib -o clipgrab clipgrab.o converter.o converter_copy.o converter_ffmpeg.o main.o mainwindow.o video.o video_youtube.o video_dailymotion.o video_vimeo.o video_myvideo.o video_myspass.o video_clipfish.o video_heuristic.o video_metacafe.o http_handler.o notifications.o qrc_resources.o moc_clipgrab.o moc_converter.o moc_converter_copy.o moc_converter_ffmpeg.o moc_mainwindow.o moc_video.o moc_video_youtube.o moc_video_dailymotion.o moc_video_vimeo.o moc_video_myvideo.o moc_video_clipfish.o moc_video_heuristic.o moc_video_metacafe.o moc_http_handler.o   -L/opt/Qt5.3.2/5.3/gcc/lib -lQt5WebKitWidgets -lQt5WebKit -lQt5Widgets -lQt5Xml -lQt5Network -lQt5Gui -lQt5Core -lGL -lpthread 
/opt/Qt5.3.2/5.3/gcc/lib/libQt5WebKit.so: undefined reference to `gst_x_overlay_set_window_handle'
/opt/Qt5.3.2/5.3/gcc/lib/libQt5WebKit.so: undefined reference to `gst_query_parse_nth_buffering_range'
/opt/Qt5.3.2/5.3/gcc/lib/libQt5WebKit.so: undefined reference to `gst_element_link_pads_full'
/opt/Qt5.3.2/5.3/gcc/lib/libQt5WebKit.so: undefined reference to `gst_is_initialized'
/opt/Qt5.3.2/5.3/gcc/lib/libQt5WebKit.so: undefined reference to `gst_query_get_n_buffering_ranges'
collect2: error: ld returned 1 exit status
make: *** [clipgrab] Error 1
15:20:43: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project clipgrab (kit: Desktop Qt 5.3 GCC 32bit)
When executing step "Make"
15:20:43: Elapsed time: 00:14.
how to solve it.