How to save and play a video file only through the Application in Android

I want to save a number of video files through the application on the mobile so that the user can not open the saved files and the files can only be run through the program and if the user finds the storage location of the desired file, can not that video file To run. In general, only saved files can be run through the application.

Like the image below, the video file is found but can not be played, this file is opened only by the Application:

Even if we convert this file to video file format, it will still not run

Just store it in your app's file directory. Those are private to your app and cannot be accessed by other apps or by users. It won't prevent a user who has rooted his device, but nothing can really prevent that.