while it's working properly with rhel-6.5 it's no longer work on 6.6 on:
gst-launch videotestsrc ! xvimagesink
this is the simplest possible pipeline. it's working on 6.5 but not on 6.6.
the cpu: Intel(R) Core(TM) i5-4440 CPU @ 3.10GHz
the motherboard: Gigabyte H97-HD3

the not working here means the video inside the xvimage not moving, but if you move the window or move the mouse inside the window it's working.

of course when using ximage sink in stead of xvimage:
gst-launch videotestsrc ! ximagesink
it's working.

it's a real serious regression.

anyway of course it's working with older cpu and motherboard but on this cpu (where the cpu itself is the graphical card) it's no longer works. it seems the latest kernel or xorg intel driver not properly support this cpu.