When your code runs under DS then AppPath is the path to where your source code and assets are stored by DS,
but if you build/install/run then Android has installed your app somewhere else (which you can't see, probably visible if you have root access).
Usually easier to use relative paths for your assets (they don't start with slash for example "Img/myimage.jpg").
Running under DS you can read from and write to AppPath/relative paths, but as an app you can only read it.
Technically to show a video requires update access, so to run your app you should extract elsewhere.
There's GetPath() "Returns the path to the local storage folder of the APK."
running under DS that means the DS folder, but in your app it means your apps folder
(useful to write a small app that runs under DS, for example to backup your apps).
Regards, ah