Den 30.11.2025 03:18, skrev Terje J. Hanssen:


Den 30.11.2025 00:16, skrev Andrew Randrianasulu:


But does it actually work? ;)

I am glad you asked :)

No, sorry - still no success with video transcoding using vulkan so far ......

At least I have not found a ffmpeg code line that works, conversion fails, similary for h264_vulkan and hevc_vulkan:

ffmpeg -hide_banner -hwaccel vulkan -i hdv09_04.m2t -c:v h264_vulkan hdv09_04_h264_vulkan.mp4
..........
Impossible to convert between the formats supported by the filter 'Parsed_null_0' and the filter 'auto_scale_0'
Link 'Parsed_null_0.default' -> 'auto_scale_0.default':
  src: yuv420p
  dst: yuv420p
[vf#0:0 @ 0x5640cf955040] Error reinitializing filters!
[vf#0:0 @ 0x5640cf955040] Task finished with error code: -38 (Function not implemented)
[vf#0:0 @ 0x5640cf955040] Terminating thread with return code -38 (Function not implemented)
[vost#0:0/h264_vulkan @ 0x5640cf9580c0] [enc:h264_vulkan @ 0x5640cf95b440] Could not open encoder before EOF
[vost#0:0/h264_vulkan @ 0x5640cf9580c0] Task finished with error code: -22 (Invalid argument)
[vost#0:0/h264_vulkan @ 0x5640cf9580c0] Terminating thread with return code -22 (Invalid argument)
[out#0/mp4 @ 0x5640cfa97e40] Nothing was written into output file, because at least one of its streams received no packets.
frame=    0 fps=0.0 q=0.0 Lsize=       0KiB time=N/A bitrate=N/A speed=N/A elapsed=0:00:00.02    
[aac @ 0x5640cfa55100] Qavg: 173.394
Conversion failed!


My google-ai friend says:

Input Format and Pixel Format:
The conversion failure often points to an incompatibility between the input video's pixel format and what the Vulkan encoder expects or can handle efficiently. 
Experiment with different input pixel formats (e.g., yuv420p, nv12) using the -pix_fmt option in FFmpeg.

Yes , FFmpeg's Vulkan components support the yuv420p pixel format. 
Specifically, the scale_vulkan filter, used for hardware-accelerated video processing via Vulkan, either defaults to or explicitly accepts yuv420p as an output format. In fact, one report indicates it may not accept other formats like nv12 when used in the format option, suggesting yuv420p is a primary supported format for Vulkan operations within FFmpeg. 
yuv420p is the most widely supported and compatible pixel format for H.264 video across almost all players and hardware decoders.


Well, I've tried several ffmpeg code lines and -pix_fmt yub420p and nv12, but so far I'm stock with the similar Conversion failures.
FFmpeg Vulkan Video Encoding is seemingly yet immature and experimental, and for example not dealt with or updated in (Decoding only)
https://trac.ffmpeg.org/wiki/HWAccelIntro#Vulkan

Trying to check with ffmpeg, I get the impression that Vulkan only use its own "vulkan" (RGBA?) pixel format and not nv12 or yuv420p

ffmpeg -hide_banner -pix_fmts | grep -i vulkan
..H.. vulkan                 0              0      0

ffmpeg -hide_banner -h encoder=h264_vulkan | egrep -i 'pix|nv|yuv'
    Supported pixel formats: vulkan

ffmpeg -hide_banner -h encoder=hevc_vulkan | egrep -i 'pix|nv|yuv'
    Supported pixel formats: vulkan