@echo off
setlocal enabledelayedexpansion

set "parent_folder=%~dp0"

for /D %%d in ("%parent_folder%*") do (
cd /D "%%d"
echo Processing: "%%d"

ffmpeg -framerate 60 -i image_%%04d.jpeg -c:v h264_nvenc -r 60 -pix_fmt yuv420p "%%~nxd.mp4"

cd ..
)

echo All folders processed.
pause

I wrote a program generating curves (unreal assets) using data in MIDI files. Those curves animate the character.

As for large intervals. nothing special has been done for that specific situation.😀