guest@slax:/dev/shm/ffmpeg$ ./ffmpeg

ffmpeg version N-120778-g7043522fe0 Copyright (c) 2000-2025 the FFmpeg developers

  built with gcc 11.2.0 (GCC)

  configuration: --enable-opencl --disable-debug --enable-libx265 --enable-libx264 --enable-gpl --enable-libplacebo --enable-vulkan --enable-libshaderc --enable-libzimg --enable-libaom --enable-libdav1d --enable-libsoxr --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-gnutls --enable-libass --enable-libbluray --enable-libcdio --enable-frei0r --enable-libgsm --enable-openal --enable-libopus --enable-librtmp --enable-libsnappy --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libv4l2 --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp

  libavutil      60. 19.101 / 60. 19.101

  libavcodec     62. 21.100 / 62. 21.100

  libavformat    62.  6.103 / 62.  6.103

  libavdevice    62.  2.100 / 62.  2.100

  libavfilter    11. 10.101 / 11. 10.101

  libswscale      9.  3.100 /  9.  3.100

  libswresample   6.  2.100 /  6.  2.100

Universal media converter

usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

Use -h to get full help or, even better, run 'man ffmpeg'

====

So, it works with ./ffplay -hwaccel vulkan file

and it also works (at 30 fps) 

./ffmpeg -hwaccel vulkan -i file -f null /dev/null

without -hwaccel it decodes at 10-12 fps (32-bit AMD FX 4300) and full cpu load. (there is much smaller cpu load for Vulcan decoding case).

full page with bigger samples:

found via Kodi user forum. May not work in Russia without using archive.org (I tried and it errored for me first).