Weird QtMultimedia GStreamer0.10 behavior

Hello,

I have built Qt5 for my BeagleBone Black (Debian Jessie) with QtMultimedia package which uses GStreamer0.10 for media playback.
I tried to run /examples/multimediawidgets/videowidget example from QtMultimedia package and play an .mp4 file, but all I get is black square (QWidget). I listed display driver devices in /usr/lib/xorg/module/devices/, currently using fbdev which outputs me the error: "FBDEV(0): FBIOPUTCMAP: Invalid argument" in /var/log/Xorg.0.log. When I set modesetting driver in xorg.conf file, it gives me no error, but it also shows just a black square.

I figured out that when I delete xorg.conf file, my video playback start to work but with lack of colors on whole display and with flickering. I don't know whether it will work if I build SGX display driver for my BBB and not use fbdev and modesetting default Linux display drivers? I really cannot figure out where is the problem, so every help and advice is appreciated!