How can i convert .rmvb to .m4v

Try this...

http://www.macupdate.com/app/mac/26235/penguin-encoder-mp4

Ipad, iphone didn't support RMVB movies, if you want to play RMVB videos on ipad, you need to convert RMVB to m4v, how to convert RMVB to m4v? Google search m4v converter, you can find a lot of m4v software, such as http://www.google.com/search?hl=en&newwindow=1&noj=1&biw=1440&bih=716&q=http%3A% 2F%2Fwww.brosvideo.com%2Fm4v-converter.html&btnG=Search is a quite good video converter.