I've followed steps in this guide. Here is output of 'vainfo' command:
libva: VA-API version 0.32.0 libva: va_getDriverName() returns 0 libva: Trying to open /usr/lib/x86_64-linux-gnu/dri/i965_drv_video.so libva: va_openDriver() returns -1 vaInitialize failed with error code -1 (unknown libva error),exit
I have Catalyst 12.6 driver installed (from debs). Also I've fixed switchable graphics bug, using this guide (STEP 2). I've tried to add 'LIBVA_DRIVER_NAME=xvba LIBVA_DRIVERS_PATH=/usr/lib/va/drivers' to /etc/environment and rebooted system, but the result was the same.