You have a Rockchip device... be happy and enjoy it!!
There is plenty of topics covering this issue of video conversion for rockchip...
If you don't want to waste time... download AVIConverter 4.0 in this site... and convert any video you have, to your device according with its screen resolution, I bet it is 220x176.
You can also be part of the sassy discussion of the topic
Meizu M6 vs Rockchip Player to know more of your awesome device!!!