Some are automatic.
As to the nonworkiong HDMI, I am running into folk that don't know their PC. That is a poor soul was showing me his PC and the dead HDMI port on the PC but the port was on the motherboard and was not supposed to work without certain CPUs. Some CPUs have graphics onboard, some do not.
As to HDMI input on a PC, too rare. You would have that in some addon card and have paid hundreds for that. So 100% unlikely.
I bought a custom build PC i didnt asemble it myself bcs of my avarage knoledge abaut computers. I would like to know if i can hook up my ps4 to my desktop and play it that way, since my monitor only has 1 HDMI input i cant connect both at the same time and constantly replugging is getting anoying. So on the back of my PC i have a vga and HDMI output wich both work but i also have another HDMI, VGA and HDMI just above them however i cant plug the VGA cable in it (dont know abaut the DVI) i tested the HDMI but it doesnt display my pc on the monitor wich lead me to think its output but when pluging my ps4 in it nothing happens either!! are these ports useless or am i doing something wrong and how can i know wheter it rly is HDMI input? (i appoligize if my english is bad)