Glossary
AV1 (AOMedia Video 1)
The open, royalty-free successor to VP9. AV1 delivers the same picture quality at a much lower bitrate than H.264, at the cost of heavier encoding, and is steadily moving from streaming into real-time calls.
General definition
AV1 (AOMedia Video 1) is an open, royalty-free video compression format developed by the Alliance for Open Media, a consortium founded by companies including Google, Amazon, Netflix, Microsoft, Mozilla, Cisco and Intel, with Apple joining later. The specification was finalised in 2018 as a successor to VP9 and a licence-free alternative to HEVC. The goal was a video codec that anyone can implement without patent royalties and that compresses better than everything before it.
On efficiency, published comparisons generally show AV1 reaching the same visual quality at around 30 percent lower bitrate than VP9 or HEVC, and roughly half the bitrate of H.264. The cost is compute: AV1 encoding is far heavier than H.264, so it depends on hardware support or on fast software encoders such as SVT-AV1, with the dav1d decoder handling playback efficiently in software.
- Browser support: Chrome, Firefox, Edge and Safari (on devices with an AV1 decoder) play AV1; YouTube, Netflix and other services stream it
- Hardware: AV1 decoding is built into recent Intel, AMD, NVIDIA, Apple, Qualcomm and MediaTek chips, with hardware encoding arriving in newer generations
- Scalability: AV1 supports scalable video coding (SVC), where one stream carries several quality layers, an alternative to sending separate simulcast streams
- Screen content: dedicated coding tools for text and sharp edges make AV1 strong for screen sharing
In WebRTC, AV1 is an optional codec negotiated alongside the mandatory VP8 and H.264. Chrome shipped AV1 for real-time calls in 2021 and favours it for screen sharing, and the RTP payload format is published by the Alliance for Open Media. Adoption in calling is gated by encoder cost on the sending device: a phone without an AV1 hardware encoder will usually fall back to H.264 or VP8 for a live call, even if it can decode AV1 without trouble.
In the Ethora ecosystem
Ethora calls are WebRTC calls routed through an SFU, and an SFU forwards packets rather than transcoding them, so which codec a call uses is negotiated between the participants’ browsers and apps in the normal WebRTC way. AV1 becomes usable in that model as soon as the endpoints on a call support and select it; nothing in the media server needs to understand the pixels. Codec support therefore follows the browsers and mobile platforms your users are on rather than a setting inside Ethora.
Where AV1 matters commercially is bandwidth. Lower bitrate at the same quality means group calls on mobile networks hold up better, and a dedicated or self-hosted deployment pays less for traffic leaving the region where the SFU runs. The trade-off is device load, which is why real-time products tend to adopt a new codec on the receiving side first and on the sending side only once hardware encoders are common.
