Autoplay Vimeo Video When Popup Pro Opens

I have a Vimeo video embedded in a popup that I created. The popup opens after a person scrolls down 5%. When the popup opens I would like the Vimeo video to autoplay. If I set autoplay=1, the video starts playing when the page loads, which means it plays before the popup opened. Has anyone created a JavaScript to trigger an autoplay when the popup opens?

Thanks!

--Craig