This is the demo which got me started looking into this:
I have repackaged everything into a very nice little package for appgyver developers.
User uploads a video,
A function in firebase converts the video to json data and creates an mp3 (or web) audio file, returns poster image or you can make it where user can select any frame as a poster.
The media is played by opening a webview using the param of the document in firebase with custom function which returns the frame player.
It loads instantly, does not crash app, and is an exceptional experience.