I would suggest using a video streaming platform such as YouTube or Vimeo and then embedding the video in your app or using a video player widget that can dynamically take a video URL from one of these services, as currently it sounds like your solution is trying to load the full 1GB file in-memory into your browser or that the widget you've chosen cannot efficiently load such big files.
Should visibility be a concern you can set your video to be unlisted on these platforms so it cannot be publicly viewed, but only through the URLs.
I hope that helps.
Try some old try-out page of mine on https://mydemoversion8-sandbox.mxapps.io/p/webcam.
Maybe you can click New and add one having a direct-link to your filelocation.
You can get the code-sample on https://github.com/TimvanSteenbergen/MyDemoVersion8