Untitled

Section "Monitor"
        Identifier      "Builtin Default Monitor"
EndSection

Section "Device"
        Identifier      "Builtin Default fbdev Device 0"
        Driver          "fbdev"
#HWcursor_false        Option          "HWcursor"          "false"
EndSection

Section "Screen"
        Identifier      "Builtin Default fbdev Screen 0"
        Device          "Builtin Default fbdev Device 0"
        Monitor         "Builtin Default Monitor"
        DefaultDepth    16
EndSection

Section "ServerLayout"
        Identifier      "Builtin Default Layout"
        Screen          "Builtin Default fbdev Screen 0"
EndSection
It's a contradiction between the variants of Qt5 and libGStreamer0.10. You really want libgstreamer1.0-0 (1.22.0-2), and gstreamer1.0-qt5 (1.22.0-5) module, and furthermore you might require gtk+3.