[Start the animation when <iFrame> is visible (AdWords)]

Is there a way to start the html banner animation WHEN the <iframe> gets on screen when developing for AdWords?

 

I am new to banner design/dev but I know my way around with html/js.

 

This is what I have found so far:

• the ad is served within an <iframe> so I cannot snoop on parent scroll position due to cross origin policy
• AdWords has a 30 sec animation limit, so if the animation starts on page load, it can be over by the time the user scrolls over it
• If it was DoubleClick I could use Enabler.isVisible to do what I want

 

So does anybody know how can I do this for AdWords (without the Enabler)?

 

Thanks!