I am currenly using JWPlayer as my HTML5 video player, but this issue applies in general to iOS.
You can't autostart/autoplay a video from a web page on iPhone because iOS disables the feature.
The only way to get a video on a web page to start playing is to touch a link or button on the screen.
I am trying to figure out how YouTube gets their videos to start.
(On iPhone 5) -
You go to http://m.youtube.com
and it shows you a bunch of images of videos.
When you touch one of the images it then appears to reload the page with a query string - e.g.
And as soon as the page reloads, the video starts to play.
Does anyone know how they are doing this?