ffmpeg -h encoder=h264_vulkan

h264_vulkan.txt

Encoder h264_vulkan [H.264/AVC (Vulkan)]:
    General capabilities: dr1 delay hardware 
    Threading capabilities: none
    Supported hardware devices: vulkan 
    Supported pixel formats: vulkan
h264_vulkan AVOptions:
  -idr_interval      <int>        E..V....... Distance (in I-frames) between key frames (from 0 to INT_MAX) (default 0)
  -b_depth           <int>        E..V....... Maximum B-frame reference depth (from 1 to INT_MAX) (default 1)
  -async_depth       <int>        E..V....... Maximum processing parallelism. Increase this to improve single channel performance. (from 1 to 64) (default 2)
  -qp                <int>        E..V....... Use an explicit constant quantizer for the whole stream (from -1 to 255) (default -1)
  -quality           <int>        E..V....... Set encode quality (trades off against speed, higher is faster) (from 0 to INT_MAX) (default 0)
  -rc_mode           <int>        E..V....... Select rate control type (from 0 to UINT32_MAX) (default auto)
     auto            4294967295   E..V....... Choose mode automatically based on parameters
     driver          0            E..V....... Driver-specific rate control
     cqp             1            E..V....... Constant quantizer mode
     cbr             2            E..V....... Constant bitrate mode
     vbr             4            E..V....... Variable bitrate mode
  -tune              <int>        E..V....... Select tuning type (from 0 to INT_MAX) (default default)
     default         0            E..V....... Default tuning
     hq              1            E..V....... High quality tuning
     ll              2            E..V....... Low-latency tuning
     ull             3            E..V....... Ultra low-latency tuning
     lossless        4            E..V....... Lossless mode tuning
  -usage             <flags>      E..V....... Select usage type (default 0)
     default                      E..V....... Default optimizations
     transcode                    E..V....... Optimize for transcoding
     stream                       E..V....... Optimize for streaming
     record                       E..V....... Optimize for offline recording
     conference                   E..V....... Optimize for teleconferencing
  -content           <flags>      E..V....... Select content type (default 0)
     default                      E..V....... Default content
     camera                       E..V....... Camera footage
     desktop                      E..V....... Screen recording
     rendered                     E..V....... Game or 3D content
  -profile           <int>        E..V....... Set profile (profile_idc and constraint_set*_flag) (from -99 to 65535) (default -99)
     constrained_baseline 578          E..V.......
     main            77           E..V.......
     high            100          E..V.......
     high444p        110          E..V.......
  -level             <int>        E..V....... Set level (level_idc) (from -99 to 255) (default -99)
     1               10           E..V.......
     1.1             11           E..V.......
     1.2             12           E..V.......
     1.3             13           E..V.......
     2               20           E..V.......
     2.1             21           E..V.......
     2.2             22           E..V.......
     3               30           E..V.......
     3.1             31           E..V.......
     3.2             32           E..V.......
     4               40           E..V.......
     4.1             41           E..V.......
     4.2             42           E..V.......
     5               50           E..V.......
     5.1             51           E..V.......
     5.2             52           E..V.......
     6               60           E..V.......
     6.1             61           E..V.......
     6.2             62           E..V.......
  -coder             <int>        E..V....... Entropy coder type (from 0 to 1) (default cabac)
     cabac           1            E..V.......
     vlc             0            E..V.......
  -units             <flags>      E..V....... Set units to include (default aud+identifier+timing+recovery+a53_cc)
     aud                          E..V....... Include AUD units
     identifier                   E..V....... Include encoder version identifier
     timing                       E..V....... Include timing parameters (buffering_period and pic_timing)
     recovery                     E..V....... Include recovery points where appropriate
     a53_cc                       E..V....... Include A/53 caption data

can you share one example? I'm only getting errors

 bhavapower ➜  media-downloader-bot git:(main) ✗  nice ffmpeg -y -threads 16 -loglevel error  -i Tiny\ Spine\ LOUD\ CRUNCHES\ \#chiropractor\ \#asmr\ \#shorts\ \[tQzuyQBZkF4\].webm  -c:v h264_vulkan -c:a libopus -b:a 61k  out.mp4   
Impossible to convert between the formats supported by the filter 'Parsed_null_0' and the filter 'auto_scale_0'
[vf#0:0 @ 0x644628aef000] Error reinitializing filters!
[vf#0:0 @ 0x644628aef000] Task finished with error code: -38 (Function not implemented)                                                                                
[vf#0:0 @ 0x644628aef000] Terminating thread with return code -38 (Function not implemented)                                                                           
[vost#0:0/h264_vulkan @ 0x644628b25d80] Could not open encoder before EOF                                                                                              
[vost#0:0/h264_vulkan @ 0x644628b25d80] Task finished with error code: -22 (Invalid argument)                                                                          
[vost#0:0/h264_vulkan @ 0x644628b25d80] Terminating thread with return code -22 (Invalid argument)                                                                     
[out#0/mp4 @ 0x644628aee5c0] Nothing was written into output file, because at least one of its streams received no packets.                                            

bhavapower ➜  media-downloader-bot git:(main) ✗  nice ffmpeg -y -threads 16 -loglevel error  -i Tiny\ Spine\ LOUD\ CRUNCHES\ \#chiropractor\ \#asmr\ \#shorts\ \[tQzuyQBZkF4\].webm  -c:v h264_vulkan -quality=10 -c:a libopus -b:a 61k  out.mp4
Unrecognized option 'quality=10'.
Error splitting the argument list: Option not found  

Sometimes the same command produces an error, sometimes it does not.
Keyframes can be specified with -force_key_frames
-hwaccel vulkan can be used for HW decoding assistance.

ffmpeg  -init_hw_device vulkan=vkdev:0 -filter_hw_device vkdev -f lavfi -i testsrc2 -t 10 -filter:v "format=nv12,hwupload" -c:v h264_vulkan -qp 20 -g 100 out.mp4
ffmpeg  -init_hw_device vulkan=vkdev:0 -filter_hw_device vkdev -f lavfi -i testsrc2 -t 10 -filter:v "format=nv12,hwupload" -c:v h264_vulkan -qp 20 -force_key_frames "expr:gte(t,n_forced*5)" out.mp4
ffmpeg -hwaccel vulkan -init_hw_device vulkan=vkdev:0 -filter_hw_device vkdev -i "h264.mp4" -filter:v "format=nv12,hwupload" -c:v h264_vulkan -qp 20 -g 100 -c:a copy out.mp4

https://trac.ffmpeg.org/ticket/11296