Using rythmbox, how can I put a m4v file inside my ipod?

Using rythmbox, how can I put a m4v file inside my ipod? I'm trying to get into my ipod a video that I downloaded from youtube. I convert it to m4v but I cannot put inside the ipod. I have an ipod nano that reproduces videos. I want to watch this video on my way to school to practice my french and my knowledge on Deleuze philosophy, ha, it is called L'abecedaire de Gilles Deleuze.