You will need a convertor to convert the videos to the right specifications so your player plays them.
Try the free open source player viDrop created by a fellow member on this site here -->
Free Open-Source converter for RockChip MPEG4 (XVID).
Or you can try the AVIConverter which can be downloaded here -->
AVIConverter v4 English.
You can also read another post by a fellow member who has a similar problem as yours here -->
http://www.mympxplayer.org/video-gt-...or-vt9967.html.
Hope that helps.