Solved poor video quality in Arch after updating Intel drivers
 

I was not able to run some games that require 3D graphics and closed instantaneously at being executed, also could not view properly video (lags).



The common error message I had was in games: ../../../src/mesa/swrast/s_renderbuffer.c:584: map_attachment: Assertion `srb->Map' failed.



I wasn't sure about this until I installed mesa-demos and runned glxgears. 

Reading the Wiki Arch https://wiki.archlinux.org/index.php/Intel_Graphics
 and choosing the SNA acceleration method I got working everything well.



Basically create a file /etc/X11/xorg.conf.d/20-intel.conf and append the following:



/etc/X11/xorg.conf.d/20-intel.conf

Section "Device"
Identifier "Intel Graphics"
Driver "intel"
Option "AccelMethod" "sna"
EndSection

Note: I was not able to see videos until I chose in vlc to take as default output X11 video and in mplayer command used "-vo X11" command"

Also edited as root /etc/mplayer/mplayer.conf which was blank adding: 
vo=x11 because local configuration file did not work.