The only file format I got to open successfully in Windows Media Player was a *.wmv. I tried various formats of *.avi and could only get the audio to come through. There is a free app you can download called PocketTv that will open *.mpeg or *.mpg but it's real picky. The encoder I use to re-encode video file formats is from ImTOO (
www.imtoo.com). I really like this application, there are many different things you can do with this app. such as video resizing, audio quality changes, and converting to many different formats. Let me know if you theres anything else.