RADV Vulkan Video Gets More Robust H.265 Decoding

[phoronix]

Phoronix: RADV Vulkan Video Gets More Robust H.265 Decoding

Mesa 23.1's RADV driver added initial support for Vulkan Video with select video formats while now a set of patches have been merged to Mesa 23.2-devel for making the H.265 (HEVC) decoding more robust...

https://www.phoronix.com/news/RADV-More-Robust-H265-HEVC

[MorrisS.]

HEVC codec is included in MESA drivers, or is provided by ffmpeg?

[V1tol]

HEVC codec is included in MESA drivers, or are provided by ffmpeg?

It is about hardware decoding so codec should be included with your GPU

[boxie]

HEVC codec is included in MESA drivers, or are provided by ffmpeg?

As I understand it, the answer is "yes"

there is a Mesa component (the radv vulkan video part)

and an FFMPEG part (to use vulkan as a video decoder)

[schmidtbag]

So, is this something that uses hardware decoders or is it something that pre-RDNA GPUs can use too?

[dlq84]

So, is this something that uses hardware decoders or is it something that pre-RDNA GPUs can use too?

It's using hardware acceleration.

[Tian]

So, is this something that uses hardware decoders or is it something that pre-RDNA GPUs can use too?

is something that uses hardware decoders so in theory any gpu with them can use it, in practice you need a driver for that gpu that supports it.

[Quackdoc]

vulkan video is super interesting, one thing I didn't realize would be how hard the implementation is on the gpu, below link is a picture showing the gpu decode for avc comparing vulkan video on the left, and vaapi on the right on my RX580 (program is Umio-Yasuno's amdgpu_top on github) as you can see the vulkan video is hammering the gpu decode block pretty hard. I didn't even realize there could be a difference before now, it also spams dmesg with errors for me (maybe related?). well actual render performance is better in mpv though so ill keep using it.

https://cdn.discordapp.com/attachments/615105639567589376/1116378913023729765/image.png

[Anux]

as you can see the vulkan video is hammering the gpu decode block pretty hard. I didn't even realize there could be a difference before now, it also spams dmesg with errors for me (maybe related?). well actual render performance is better in mpv though so ill keep using it.

Maybe the vulkan path can offload more work to the HWdec wich is what we want but I would assume that this large difference is a bug. If the performance is already better than the other solutions the future looks bright.

[agd5f]

Maybe the vulkan path can offload more work to the HWdec wich is what we want but I would assume that this large difference is a bug. If the performance is already better than the other solutions the future looks bright.

The actual work offloaded should be the same. I suspect the difference is that the vulkan command submission model doesn't align well with existing video encode/decode APIs and thus the underlying hardware and firmware. I suspect vulkan ends up doing more work than it needs to overcome this mismatch.