A Technical Overview of VP9—The Latest Open-Source Video Codec

Google has recently finalized a next-generation open-source video codec called VP9, as part of the libvpx repository of the WebM project (http://www.webmproject.org/). Starting from the VP8 video codec released by Google in 2010 as the baseline, various enhancements and new tools were added, resulting in the next-generation bit stream VP9. The bit stream was finalized with the exception of essential bug fixes in June 2013. Prior to the release, however, all technical developments were being conducted openly in the public experimental branch of the repository for many months. This paper provides a brief technical overview of the coding tools included in VP9, along with coding performance comparisons with other state-of-the-art video codecs—namely, H.264/AVC and HEVC—on standard test sets. While a completely fair comparison is impossible to conduct because of the limitations of the respective encoder implementations, the tests show VP9 to be quite competitive with mainstream state-of-the-art codecs.