[FFmpeg-user] ffmpeg complains that late SEI is not implemented

[Dmitry Katsubo]

Dear ffmpeg community,

I have the ffmpeg v5.1-full for Windows x64 downloaded from https://www.gyan.dev/ffmpeg/builds/

When I start video encoding:

ffmpeg.exe -i in.mkv -c:v libx264 -crf 28 -profile:v high -an out.mkv

it dumps so many messages like this to console:

ffmpeg version 5.1-full_build-www.gyan.dev Copyright (c) 2000-2022 the FFmpeg developers
...
[h264 @ 00000142dcc60c40] sps_id 1 out of range
Input #0, matroska,webm, from './HOW TO TRAIN YOUR DRAGON 3D_t01.mkv':
...
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
[h264 @ 00000142dcd05180] sps_id 1 out of range
[h264 @ 00000142de85e600] Late SEI is not implemented. Update your FFmpeg version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been
implemented.
[h264 @ 00000142de85e600] If you want to help, upload a sample of this file to https://streams.videolan.org/upload/ and contact the ffmpeg-devel mailing list. (ffmpeg-devel at ffmpeg.org)
[h264 @ 00000142dd30ee80] Late SEI is not implemented. Update your FFmpeg version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been
implemented.
[h264 @ 00000142dd30ee80] If you want to help, upload a sample of this file to https://streams.videolan.org/upload/ and contact the ffmpeg-devel mailing list. (ffmpeg-devel at ffmpeg.org)
... repeated thousands of times ...

I am not sure if output video at the end will be consistent, or am I wrong and I can silently ignore the messages?

When I start x264 from CLI, it shows few warnings, but generally runs more smoother:

x264.exe --crf 28 --profile high444 -o out.mkv in.mkv

lavf [info]: 1920x1080p 1:1 @ 24000/1001 fps (vfr)
x264 [info]: using SAR=1/1
x264 [info]: using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
x264 [info]: profile High, level 4.1, 4:2:0, 8-bit
[h264 @ 0000000002757a80] sps_id 1 out of range
[h264 @ 0000000002757a80] sps_id 1 out of range

Is "Late SEI (Supplemental enhancement information)[1]" feature implementation specific to ffmpeg? Or is it codec-specific feature and the difference is only the way how warnings are logged?

Any comment is warmly welcomed.

[1] https://en.wikipedia.org/wiki/Advanced_Video_Coding#Overall_history

-- 
With best regards,
Dmitry