VK_MESA_video_decode_av1: Early Vulkan AV1 Decoding For Open-Source Radeon Driver
FFmpeg developer Lynne and well known open-source graphics driver developer David Airlie of Red Hat decided to come up with VK_MESA_video_decode_av1 as their own vendor extension to support AV1 video decoding with Mesa's RADV driver. This extension is just designed for RADV and more than likely a stop-gap measure until the formal AV1 encode/decode extensions are published later this year. This Mesa vendor extension may also not be suitable for other drivers/vendors due to catering toward the AMD hardware's AV1 handling.
This VK_MESA_video_decode_av1 extension work is in addition to their work on getting RADV Vulkan Video working nicely with the H.264 and H.265 extensions and also seeing that it works well for the FFmpeg multimedia framework purposes.
Airlie blogged briefly about this new AV1 video decode extension while Lynne has written more at length in this blog post. The VK_MESA_video_decode_av1 extension is currently working with a fork of Airlie's RADV driver code and Lynne's FFmpeg Vulkan branch.