The red background is due to the DEBUG switch. Turn that off, compile and the background should be black again. I you want to keep the debug output, you'll have to edit VaapiBlackSurface() in video.c: you'll find the debug block around line 4486...
Btw, some notes about the xf86-video-intel driver version: https://github.com/OpenELEC/Op…8d4931b5faa16bad7392eb6b7