AV1

What is AV1?

AOMedia Video 1 (AV1) is an open, royalty-free video coding format initially designed for video transmissions over the Internet. It was developed as a successor to VP9 by the Alliance for Open Media (AOMedia), a consortium founded in 2015 that includes semiconductor firms, video on demand providers, video content producers, software development companies and web browser vendors. The AV1 bitstream specification includes a reference video codec. In 2018, Facebook conducted testing that approximated real world conditions, and the AV1 reference encoder achieved 34%, 46.2% and 50.3% higher data compression than libvpx-vp9, x264 high profile, and x264 main profile respectively.

Like VP9, but unlike H.264/AVC and HEVC, AV1 has a royalty-free licensing model that does not hinder adoption in open-source projects.

AVIF is an image file format that uses AV1 compression algorithms.

The primary drawback to AV1 at this time is that it is very new, and support is still in the process of being integrated into most browsers. Additionally, encoders and decoders are still being optimized for performance, and hardware encoders and decoders are still mostly in development rather than production.

Up to this day, YouTube is gradually rolling out the codec and even starts shipping AV1 streams on compatible Android TV devices. Now AV1 codec is well supported in the latest version of Chrome, Firefox, Edge and Opera, learn more about Browser availability table for AV1 on caniuse.

AV1 Profiles

AV1 defines three profiles for decoders which are Main, High, and Professional. The Main profile allows for a bit depth of 8- or 10-bits per sample with 4:0:0 (greyscale) and 4:2:0 (quarter) chroma sampling. The High profile further adds support for 4:4:4 chroma sampling (no subsampling). The Professional profile extends capabilities to full support for 4:0:0, 4:2:0, 4:2:2 (half) and 4:4:4 chroma sub-sampling with 8, 10 and 12 bit color depths.

Profile Bit depth Chroma subsampling
8 10 12 4:0:0 4:2:0 4:2:2 4:4:4
Main + + + +
High + + + + +
Professional + + + + + + +