Each time that you play different video content, you
must initialize a MediaResource instance with information about
the video content, then load the media resource.
Create a media resource
The MediaResource class represents the content that is about to be loaded by the MediaPlayer class.
Load a media resource using MediaPlayerItemLoader
Another way to resolve a media resource is with MediaPlayerItemLoader. This is useful when you want to obtain information about a particular media stream without the full instantiation of a MediaPlayer instance.