TV Remote using a Cellphone

I was wondering if it's possible to build an app which works as a TV remote, I'开发者_运维技巧ve been googling around but so far all I've found are apps that already do or attempt to do it, but nothing that gives me an idea of how to achieve this. Does anyone know? I want to try and do it for an android phone.

Phones generally don't have IR(infrared) ports, so that isn't much of an option.

you can cling library its url is mentioned below http://4thline.org/projects/cling/