Netflix introduced the ability to download content so you can watch it offline on mobile devices this week, which is fantastic news for subscribers to the streaming platform, as it now means you can do things like watching content on slower connections where streaming isn’t ideal or save things to watch on a long-haul flight!
To help people deal with storage demands on their mobile devices, as well as save on bandwidth for both their uploads and your downloads, they’ve started to deploy a new codec. While streaming, they still exclusively use H.264/AVC, but when it comes to downloads on Android, it’s their new VP9 codec, which is an open source video codec created by Google, allowing for same video quality while reducing data usage!
While you would think it makes sense to use that everywhere, not every device supports it. Android is the obvious starting place, as Google obviously support their own codec. Apple on the other hand? No support for VP9 at all, and no sign they’ll be doing so anytime soon. Netflix is helping other devices by using their H.264/AVC High encoding profile for downloads on no VP9 devices, while still using their AVC Main encoding on streaming. They even go as far to use slightly different encoding per show/movie, helping them reduce their data overheads even further. While downloads are chopped up and each one-to-three minute part is encoded in the most optimal format, very clever.
All this is a lot of work, bu tit saves them and you around 37% of bandwidth on average for a video, without them looking different to the end user. Faster streaming, smaller downloads, less data usage, same quality!
