A Stream Media Source is an asset that enables you to stream a video in the supported URL format inside Unreal Engine 4 (UE4).
With the stream defined, you can load it up and play it inside UE4 with a Media Player asset and (with an associated Media Texture) can assign it to various aspects of your level.
The stream can be loaded and played as part of a UI element, played fullscreen or even applied to a Static Mesh (such as a TV) and played inside your level.
For this how-to, we use Unreal Motion Graphics (UMG) to create a UI element that will play a streamed video fullscreen.
For this how-to we are using the Blueprint Third Person Template project with Starter Content enabled.
After playing in the Editor, the video will start playing back in full screen as part of our HUD Widget Blueprint.
Similar to using a File Media Source which plays a video file from disk, Stream Media Sources will automatically play when calling Open Source if their associated Media Player asset are set to Play on Open which by default is enabled.
There are additional commands you can issue to the Media Player asset such as pausing, rewinding or stopping the video once it has begun playing which can be found under the Media Player section when dragging off the Media Player Reference.