Option 1: mp4 uploaded into website. Must be under 20mb.
Visitor presses play. Automatically scales correctly on mobile.

Option 2: Youtube video or upload to background of section.
No sound options.
Custom code to make it the right ration on mobile ( have not done here, takes time).
If you use youtube your account name will always appear in the top left corner for a few seconds.

Option 3: Upload video under 20mb
Must have border.
Autoplay - videos play on mute with autplay but the option is there to turn on sound.