Preset help specified, but could not be opened.

[monochromec]

Summary of the bug:
When trying to obtain a list of presets (according to ​https://trac.ffmpeg.org/wiki/Encode/H.264#Listpresetsandtunes ), ffmpeg reports "Preset help specified, but could not be opened."
How to reproduce:

% ffmpeg -hide_banner -f lavfi -i nullsrc -c:v hevc -pre help -f mp4 -
ffmpeg version 6.0
built on Debian bullseye

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.

[hungkuishing]

you need specify "-preset", not "-pre"!

for h264:
ffmpeg -hide_banner -f lavfi -i nullsrc -c:v libx264 -preset help -f mp4 -

for h265:
ffmpeg -hide_banner -f lavfi -i nullsrc -c:v libx265 -preset help -f mp4 -

notes: "-pre" will specify a avpreset file which contains encoder-specific options in it.