Questions of cuda video decoder

Hi everyone

I have tried cuda video decoder on mulit processing which means I tried to run four video decoder at a same time
but the program crash after the fifth one… My question is is there a document talking about the limitation of cuda video decoder??
(like how many video can it decoded at one time and the size of the video 1024*768??)
and spec of VP2? I have searched these two for a long time, but I can’t find any useful information

Thanks for help
Andy