Youtube VP9 live stream vod artifacts with hwdec=vulkan on windows & nvidia

mpv Information

mpv v0.40.0-301-g77dee9be2 Copyright © 2000-2025 mpv/MPlayer/mplayer2 projects
 built on Sep  7 2025 17:01:57
libplacebo version: v7.354.0 (v7.351.0-67-g515da95-dirty)
FFmpeg version: N-121009-g45db6945e
FFmpeg library versions:
   libavcodec      62.15.100
   libavdevice     62.2.100
   libavfilter     11.8.100
   libavformat     62.5.100
   libavutil       60.12.100
   libswresample   6.2.100
   libswscale      9.3.100

Other Information

- Windows version: Windows 11 LTSC 24H2
- GPU model, driver and version: Nvidia 3060 driver 581.15  
- Source of mpv: latest git build by zhongfly
- Latest known working version: ???
- Issue started after the following happened:

Reproduction Steps

VP9 livestream from youtube

On nvidia gpus under windows any vp9 vod of a Youtube live stream exhibits artifacts, while using hwdec=vulkan
this is config that i first experienced the issue with. This does not happen on my 7950x's igpu (RDNA2)

vo=gpu-next
hwdec=auto
gpu-api=vulkan

but it seems to happen with any config that supports hwdec=vulkan, including on vo=gpu. the problem is resolved by setting hwdec=nvdec,auto

Expected Behavior

No corruption while using hwdec=vulkan

Actual Behavior

video corruption

Log File

output.txt

Sample Files

https://www.youtube.com/live/CcBNYw8pjs8

any of the vp9 formats (315|308|303...) exhibit this issue

I carefully read all instruction and confirm that I did the following:

• I tested with the latest mpv version to validate that the issue is not already fixed.
• I provided all required information including system and mpv version.
• I produced the log file with the exact same set of files, parameters, and conditions used in "Reproduction Steps", with the addition of --log-file=output.txt.
• I produced the log file while the behaviors described in "Actual Behavior" were actively observed.
• I attached the full, untruncated log file.
• I attached the backtrace in the case of a crash.

Start by reproducing the linked YouTube VP9 stream with the shown gpu-next, Vulkan, and hwdec settings, using output.txt for the captured diagnostics. Compare the corrupted hwdec=vulkan behavior with hwdec=nvdec,auto; done means the VP9 live-stream VOD plays without video artifacts on the affected Windows and Nvidia setup.