Given YouTube’s massive scale it isn’t a surprise that the company has plenty of custom tools running in the backend to transcode video as quickly as possible (this transcoding system is calledViper). Kaiser says that one key speed improvement that was recently introduced has to do with the order in which videos are processed — the steps used to happen in sequence and are now being run in parallel, which has led to a “huge improvement’ in the time in takes to get a video live.
How big? Today, 60% of all videos go live in under one minute — a year ago, no videos were being processed that quickly.
As for the challenges the team is currently focused on, Kaiser says that the need for quick and seamless playback — which is obviously always a key issue — is greater than ever, especially when it comes to delivering content to televisions. The team is currently implementing adaptive streaming, which changes the bitrate of a video on the fly depending on your connection speed (videos on Hulu, Ooyala, and some other sites already do this). When I asked if this would be coming to HTML5 any time soon (which is the direction YouTube is slowly heading toward), Kaiser said that it’s not implemented anywhere right now, but that it’s working to make it a reality.
Kaiser also discussed one ‘trick’ YouTube uses to quickly serve all those videos around the world. The company has built and deployed hundreds hardware devices worldwide that cache and serve up the most popular YouTube videos, in much the same way that a CDN does.