Play video in android from SDCard

I am trying to play audio & video files from SDcard in Android.

While playing videos using native.video() api, I am getting IllegalStateException.

I accessed as below:

local video = native.newVideo( display.contentCenterX, display.contentCenterY, 320, 480 );

video:load("/storage/emulated/0/myapp/assets/video/myvideo.m4v");

video:play();

When I tried placing the same video bundled in the application, it works fine. 

eg: video:load(“assets/video/myvideo.m4v”, system.ResourceDirectory);

But the requirement I have is to access from SD_card and play.

Please help. Its really Urgent.

Any working sample would be great. 

Thanks in advance,

Swati