using intel vpadu for video decoding

[5l1v3r1]

Ok i followed your method and everything seems in order but the problem is, the default renderer device is nvidia which bounds to /dev/dri/renderD129 and intel integrated card is loaded in kernel but inactive which bounds to /dev/dri/renderD128 My nvidia card is 840m which does not support vpdau or vaapi means cannot decode video streams in firefox, chromium etc.. At some particular programs like ffmpeg and vpainfo etc i can add some env variables to .bashrc like (export LIBVA_DRIVER_NAME=i965 and export VDPAU_DRIVER=va_gl) and can run the program with --display drm --device /dev/dri/renderD128 parameter to take advantage of intel's integrated card's vpdau. But i cannot do the same with patched chromium and new firefox which supports vaapi and vpdau. Do you know how to overcome this issue? I want to force intel card to be used in only chromium and firefox and the rest can be handled by nvidia I do not want to use nvidia-xconfig or bumblebee because they are not stable and screen tearing appears.