This application gathers two metrics for player performance: time to first frame (TTFF) and time to player ready (TTPR). Two web pages (let's call them emitters), one for the HTML5 player and one for the Flash player are hosted on Google App Engine. These web pages emit the TTFF and TTPR metrics to Google Analytics via JavaScript.

The emitters are periodically called from different parts of the world using webpagetest.org. The webpagetest.org jobs are kicked off by a cron job running from Google App Engine. See cron.php and cron.yaml.