Update: As it turns out, AMD's RDNA 3-based GPUs with VCN 4.x engines support hardware AV1 encoding, according to Linux driver patches released by AMD and discovered by @Kepler_L2. Previously, we reported based on Linux patches that AMD's upcoming Radeon RX 7000-series GPUs did not support AV1 encoding, which is not correct. We've modified the text to reflect the new information.
As part of the ongoing enablement of AMD’s next generation RDNA 3 GPUs, the company has released a series of patches for Linux that reveal details about the company’s upcoming video engines, the Video Codec Next version 4.x. Based on the information we have, VCN 4.x supports decoding of virtually all modern codecs.
AMD's VCN 4.0 engine appears to support H.264/MPEG 4 AVC, H.265, VP9, AV1, and JPEG decoding, as well as AV1, H.264, and H.265 encoding. For now, VCN does not appear to support H.266/VVC (versatile video coding) decoding/encoding. VVC is a next-generation codec that will be required maybe in 2023 or 2024 (when appropriate content becomes available), while AV1 is a current generation codec with expanding usage. There are users and companies that would like to have it now for encoding or transcoding video, but later this year should also suffice.
Intel's Arc Alchemist GPUs fully support AV1 decoding and encoding, the only chips to do so at present. We expect Nvidia may also support AV1 encoding with it's upcoming Ada architecture, though that remains as yet unconfirmed. AMD's RDNA 3 also won't arrive until later this year, but if AMD's VCN 4.x indeed does support AV1 encoding, all three major GPU companies will then offer hardware accelerated AV1 encoding and decoding.
AMD's current-generation GPUs based on the RDNA 2 architecture use the company's VCN 3.0, VCN 3.1, and VCN 3.1.2 video decoding blocks. By contrast, next-generation RDNA 3 graphics processors (at least the so-called SoC21, which is believed to be Navi 31) will feature the next-generation VCN 4.0 engine, according to a new Linux patch posted by AMD and discovered by @Kepler_L2.
Speaking of VCN 4.0, even the current VCN 3.x engine fully supports H.264/MPEG4 AVC, H.265, VP9, AV1, and JPEG decoding as well as H.264 and H.265 encoding. Unless there are more innovations, the key improvement with VCN 4.0 over 3.x will be hardware accelerated AV1 encode/decode support. It may also support higher resolutions, color depths/formats, and/or efficiency improvements, and we anticipate some additional feature set changes as well.
Keep in mind that not all GPU features get enabled ahead of launch, especially in Linux due to various legal and technical reasons. We'll find out for sure what VCN 4.x and RDNA 3 add to the feature list likely late this year, when we expect the RX 7000-series GPUs to launch.