How to play videos from my PDA in iPod clic?

I just sync my PDA (windows based) to my laptop. And i want to move it to my ipod. But,if i open it in Quick Time Player. It always say that the file isn't recognize (i can play it on my PDA though). i've tried to sync it to ipod. But the ipod doesn't recognize too. what should i do to make it recognize.? thank's