Check the tables on this page for media file type/encoding compatibility (scroll down a screen or two):
http://sience.schattenkind.net/dingoo/Dingoo_a320_eng.htm
There is a ton of useful information there, be sure to check it out.
Yes this is the most useful link to troubleshoot video on the Dingoo!
First of all, don't forget that MP4, AVI and VMW aren't video formats : they are containers! So they can "contain" pretty much any type of video.
How to know if your video file is dingoo compatible :
- download ffmpeg
- execute in a command line "ffmpeg -i video_file_name.avi"
- you'll see the video/audio bitrate, the video resolution etc.
- now compare these numbers to the ones on Science's pages
- convert your videos to the appropriate bitrate/format/codec