A Linux kernel patch submitted by AMD reveals the RDNA2 architecture has AV1 codec support. VideoCardz reports both Navi 21 and Navi 22 have this implementation.
AV1 is a new codec that promises up to 50 percent higher bitrate efficiency than H.264, and 30 percent higher efficiency than VP9 and HEVC. It's also supported by NVIDIA's GeForce RTX 30 series as well as the Xe-based integrated graphics found on Intel's Tiger Lake processors.
The AV1 decoding support is becoming a standard. Intel’s Tiger Lake series featuring Xe-LP architecture already supports AV1 decoding. The just-announced NVIDIA GeForce RTX 30 series will also have full AV1 acceleration through a built-in hardware decoder.
Microsoft is adding AV1 Video Extension which should boost AV1 performance in Windows 10 at a higher resolution. Google also updated its Chrome web browser on Windows 10 to support AV1 hardware decoding.