I wanted to echo Steven and Josh, and note there is no direct integration. That said, this use case is simple to set up if you have the technical resources. To do this:
1 - Embed a YouTube on your webpage
2 - Use YouTube's iframe to gather data based on predefined criteria
https://developers.google.com/youtube/iframe_api_reference
3 - Send data to Marketo via Munchkin
http://developers.marketo.com/documentation/websites/lead-tracking-munchkin-js/