Intel HW Acceleration Notes:

apt-get install i965-va-driver
#add non-free non-free-firmware to debian apt config
apt-get install i965-va-driver-shaders
apt-get install intel-media-va-driver-non-free 

check at least one renderD device is available:

ls -l /dev/dri

check supported QSV/VA-API codecs:

  iHD driver indicates support for the QSV and VA-API interfaces.
  i965 driver indicates only support for the VA-API interface, which should only be used on pre-Broadwell platforms.

sudo apt install vainfo
sudo vainfo --display drm --device /dev/dri/renderD128

Check the OpenCL runtime status:

ffmpeg -v verbose -init_hw_device vaapi=va:/dev/dri/renderD128 -init_hw_device opencl@va
sudo apt install -y intel-opencl-icd

This enables QSV or VA-API

If you wish to use the second GPU on your system, change renderD128 to renderD129.

apt-get install intel-microcode 
echo "options i915 enable_guc=2" >> /etc/modprobe.d/i915.conf

sudo apt-get install intel-gpu-tools

# show all supported hardware devices by ffmpeg version

ffmpeg -v verbose -init_hw_device list

apt-get install va-driver-all libva-drm2 mesa-va-drivers
usermod -a -G render root
usermod -a -G video root