Crash playing video using gl output plugin

[Pavel Troller]

Hi!
  I'm trying to use the mp[ayer's gl or gl2 output plugin because the default
xv plugin is now unable to regulate video parameters like brightness, contrast
etc.
  For the first time, the video plays well. For the second time, Xserver always
crashes with the following report in its log:
..
(II) Mouse0: ps2EnableDataReporting: succeeded
SetGrabKeysState - enabled

Backtrace:
0: /opt64/X11/bin/X(xf86SigHandler+0x6a) [0x49535a]
1: /lib64/libc.so.6 [0x2aaaabbc5510]
2: /lib64/libc.so.6(memcpy+0x60) [0x2aaaabc0c080]
3: /opt64/X11/lib/xorg/modules/extensions//libglx.so [0x2aaaac50198e]
4: /opt64/X11/lib/dri/i915_dri.so(__driUtilUpdateDrawableInfo+0xde) [0x2aaabe4ea41e]
5: /opt64/X11/lib/dri/i915_dri.so [0x2aaabe4ea615]
6: /opt64/X11/lib/xorg/modules/extensions//libglx.so [0x2aaaac500b61]
7: /opt64/X11/lib/xorg/modules/extensions//libglx.so(DoMakeCurrent+0x36d) [0x2aaaac4d1e1d]
8: /opt64/X11/lib/xorg/modules/extensions//libglx.so [0x2aaaac4d3ae1]
9: /opt64/X11/bin/X(Dispatch+0x2e2) [0x446c32]
10: /opt64/X11/bin/X(main+0x465) [0x42f855]
11: /lib64/libc.so.6(__libc_start_main+0xf4) [0x2aaaabbb22f4]
12: /opt64/X11/bin/X(FontFileCompleteXLFD+0x229) [0x42eb39]

Fatal server error:
Caught signal 11.  Server aborting

(II) AIGLX: Suspending AIGLX clients for VT switch
(II) intel(0): xf86UnbindGARTMemory: unbind key 1
..

It happens with git master branches of Xserver, mesa and xf86-video-intel. 
Guessing from the log, the problem is in Mesa. Any hints, how to fix ?
Or what more to debug ?
                       With regards, Pavel Troller