This is the website I already done:
I used backstretch JS script for the background videos, also it was easy to make since I can control WHEN certain video is played.
BUT I have reports that it have some animations issues when using Safari, so I decided to move the videos back to hype and control them directly with hype tools.
BUT #2, using hype for the videos results in some artifacts when switching between videos, here you can find the hype file Im using for the test:
Here is a video showing the visual artifacts: