There is a sample UI asset for controlling LeiaMedia which are playing back videos. See the "LeiaVideoSampleUI" object and LeiaMediaVideoSampleUI.cs files
Recording Leia Media
It is possible to record LeiaMedia using an editor-only tool within the Leia Unity SDK. Once LeiaMedia is generated, the LeiaMedia can be used as a resource in a built project and can be displayed to users like any other LeiaMedia.
In Unity 2017.3+, this tool can record mp4s.
In all Unity versions supported by the Leia Unity SDK, this tool can record jpgs and pngs.
An example of a scene that has been configured for recording is provided for users in the "ExampleRecordScene"