I just got a camera/mp3/mp4 player from china. I've been trying to put video files on it, but when I try and play it on the mp4 player, it says the format is not supported. However, the file i've been trying to put on is an .avi file, and the mp4 player came preloaded with an ice age 2 trailer, also in .avi format. What's gone wrong? Do i have to convert my video files? Or do i have to install some sort of software/codec on the player?