Our goal was to assess what can be achieved by encoding with practical codecs that can be deployed to a production pipeline, on the Netflix catalog of movies and TV shows, with encoding parameters that are useful to a streaming service. Most codec comparisons in the past focused on evaluating what can be achieved by the bitstream syntax (using the reference software), applied settings that do not fully reflect our encoding scenario, or only covered a limited set of videos. We ran a large-scale comparison of x264, x265 and libvpx to see for ourselves whether this 50% bandwidth improvement is applicable to our use case. YouTube reported that by encoding with VP9, they can deliver video at half the bandwidth compared to legacy codecs. Concurrent to HEVC, Google developed VP9 as a royalty-free video compression format and released libvpx as an open-source software library for encoding VP9. x265 is an open-source HEVC encoder, originally ported from the x264 codebase. HEVC is the successor to H.264/AVC and results reported from standardization showed about 50% bitrate savings for the same quality compared to H.264/AVC. x264 is the most established open-source software encoder for H.264/AVC. H.264/AVC is a very widely-used video compression standard on the Internet, with ubiquitous decoder support on web browsers, TVs, mobile devices, and other consumer devices. Part of the effort is to evaluate the state-of-the-art video codecs, and adopt them if they provide substantial compression gains.

Our team works on improving our video compression efficiency to ensure that we are good stewards of the Internet while at the same time delivering the best video quality to our members. As we grow globally, more of these video bits will be streamed through bandwidth-constrained cellular networks.

With 83+ million members watching billions of hours of TV shows and movies, Netflix sends a huge amount of video bits through the Internet. By Jan De Cock, Aditya Mavlankar, Anush Moorthy, and Anne Aaron

X264 video codec