Ubuntu 14.04/Trusty has reached End of Life (EoL) for standard support
and the nvidia-173 package is not included in the Extended Security
Maintenance plan:
https://wiki.ubuntu.com/SecurityTeam/ESM/14.04#A14.04_Infrastructure_ESM_Packages
** Changed in: nvidia-graphics-drivers-173-updates (Ubuntu)
The nvidia 173 driver is meant to support GeForce FX 5 through GeForce
7000 series cards. These cards do have some video acceleration, but they
do not support libvdpau.
https://en.wikipedia.org/wiki/Nvidia_PureVideo#Nvidia_VDPAU_Feature_Sets
Although the 173.xx driver does support GeForce 8000 - G
