ср, 25 февр. 2026 г., 16:09 Andrea paz <[email protected]>:
Andrea, could you add that to the hardware performance section in Latex
for the Manual if you have time?
To add Vulkan to the manual, I would need some clarification.
Decoding: 1- Is the “vulkan” setting in Preferences --> performance only valid for amdgpu?
It should work for other Vulkan drivers exposing those Vulkan video extensions. Notably new Nvidia with proprietary drivers, and somewhere at Mesa3d's freedesktop MergeRequests I saw patch for Nouveau's NVK driver (decode only for now). 2- Is there a need for libplacebo and certain environmental variables?
Which ones?
as far as I understand - libplacebo may only be needed for ffv1 de/en coding via Vulkan, but mostly because it pulls shader compiler as dependency.. Vulkan SDK must be new enough so ffmpeg-8.0 build will recognize decoding extensions, they were added in late 2023, see Phoronix or Khronos websites. https://airlied.blogspot.com/2023/12/radv-vulkan-video-encode-status.html?m=... === Vulkan 1.3.274 moves the Vulkan encode work out of BETA and moves h264 and h265 into KHR extensions. === Some hardware should work without any variables, my RX 550 need RADV_PERFTEST=video_decode. https://www.phoronix.com/news/Vulkan-Video-VCN2-VCN3-Default 3- Is there anything else about vulkan that should be included in the
manual?
FFV1 decoding might be slower than software, depending on how fast your GPU is?
Encoding: 4- Are presets with Vulkan hardware agnostic? (Apart from Intel with problems in ANV).
In theory ... Whole point of Vulkan was having some cross-platform, cross-vendor solution for video decode/encode (it may even work inside qemu VM, if it was compiled with Vulkan passthru support? vaapi support was developed but not accepted upstream) 5- Is there a need for libplacebo and certain environmental variables?
Which ones?
libplacebo for now enables ffv1 Vulkan encoding. I am not sure how many amdgpu supported GPUs were enabled by default in recent mesa, I think your still need RADV_PERFTEST=video_encode ? So depending on Mesa driver version and gpu, I'd say? https://www.phoronix.com/news/Mesa-25.2-VCN5-RDNA4-Video https://docs.mesa3d.org/envvars.html#radv-env-vars 6- Is there anything else about vulkan that should be included in the
manual?
Not much, for me it was fastest *decode* method for HDR 4K HEVC test file (using X11 direct) but I guess this heavily depend on GPU.