Trying to read a video file on AIR app included in the project

I'm trying to make my app, able to read a video.

It's working on desktop, but when I'm trying on my Android or IOS device, it's not.

So I suppose it's a path problem.

Here's what I've tried (Working on my desktop, but not on my device. And yes, I've included the videos to my project ) :

stream.play( "bougna.mp4") ; 

I've tried this too :    

var bougnaVideo:File = File.applicationStorageDirectory; 
bougnaVideo = bougnaVideo.resolvePath("bougna.mp4"); 
stream.play(bougnaVideo) ;

But both of the methods don't work.

Any idea why ?