Well , till quite some time back I have been using some Youtube video downloader application, most of which have stopped working now. So, there was this one awesome video which I wanted to download.
Suddenly, I come to stuck with this simple logic, that hey if firefox is playing this video then it must be downloading that video onto the memory and then playing it. So why don't I pick up this video from there. So the most obvious place to check for such a thing was the /tmp/ folder ( I am on Ubuntu currently) and voila here it was resting in peace waiting for me to close the tab and get deleted.
So all that one has to do for his home made Youtube Downloader to work is to cut this video from your temp folder and save it at some good place before you close the tab and here you go, you home made Youtube Downloader is ready.