MediaSurfacePlugin definition and struck picture issue

we meet two issues:
1.the 3d360video using android media surface plugin seem the definition not very high.
using the app in http://www.utovr.com/, same video with higher definition than oculus.
Do oculus has some ways to impove it?
2.while using android media surface plugin to play online mp4, it will take long time to load online source.
stuck at 
mediaPlayer.Call("setDataSource", mediaPath); 
and the picture also hang until it process finished.
I also try to do it using System.Threading.Thread to avoid, but it crash and report 

JNI ERROR (app bug): accessed stale local reference 0x200001 (index 0 in a table of size 0)

Do there have a way to avoid it. 
Thanks you for your help~