AMD Posts Linux Driver Patches For New "VCN 4.0" IP Block

After last week AMD began posting the "GFX11" patches for RDNA3, today AMD published a set of patches enabling the VCN 4.0 IP block for next-generation video encode/decode capabilities.

AMD has begun posting the AMDGPU Linux kernel graphics driver patches for enabling Video Core Next 4.0 under open-source. While this patch series is posted independently as part of their new IP block-by-block enablement strategy, given the timing it's safe to probably assume VCN4 is coming with the next-generation "RDNA3" graphics cards.

The Video Codec Next 4 patches (normally VCN refers to "Video Core Next" while either a typo or a rename, it's referred to now as "Video Codec Next") were sent out today and consist of around 12.3k lines of new code, but more than 9k lines of that are register header files. This is just the start and enough to get the VCN video coding IP block working with existing supported codecs.

With VCN 3.0/3.1 already handling AV1 decoding, it will be interesting to see what new comes with VCN 4.0 -- hopefully AV1 encode would be great to see. The patch series today though is just the basic kernel driver side enablement and so far no new code published for Mesa or other user-space components around VCN4. With this kernel patch series for the VCN4 capabilities is just exposing 4K HEVC and MPEG4 AVC encode while on the decode side is MPEG 4 AVC / HEVC / JPEG / VP9 / AV1. The AV1 decode is limited to 8K and lower. We'll see what future patch series bring to the VCN4 features.

This initial VCN4 bring-up patch series can be found on the mailing list while undergoing review and eventually working its way to the mainline Linux kernel.