Is There Another Way To Convert Video To Flv At Runtime Using Php?

I couldnt get the ffmpeg at all. I mean i really dont know how to install it.
And my webbased hosting doesnt have ffmpeg installed. Heres the thing, im doing backend or CMS for a client. So there would be video section on frontend. So the backend should have page where video can be uploaded. Unfortunately, when you upload flv file, it doesnt work. So it really needs to be converted as it is uploading. Just like in youtube. It doesnt matter if i need to program it in PHP and AJAX.
i did research regarding this and FFMPEG appears in most of the results. Ok i really dont get the instructions. Besides, even i got how to install it on my local pc. On my web-based hosting, it wouldnt be installed, because hosting companies who are talking to us like smart kids are totally idiot.
Now, are there any options besides ffmpeg?