[afedchin]

yep in red/cyan i get broken gui and video

So, the dxva renderer doesn't support default backbuffer format as I expected. But why? And why drivers still report what format supported? Seems like drivers support it but cannot work with it. Strange.
Workaround which I implemented in current branch should solve the issue. Still need to determine which drivers has this issue because workaround causes an extra shader execution.