ChatGPT was suggesting something like this:What do you mean by it runs too fast? If you're combining a series of image frames, you can change the frame rate at which ffmpeg converts to video using the -r flag.
You must be registered to see the links
ffmpeg -f concat -safe 0 -r 15 -i input.txt -vsync vfr -pix_fmt yuv420p -c:v libvpx-vp9 output.mp4
If i change to -r 30, it will be less than 1s and the output video will be fast so thats why i was asking if anyone know the commands in ffmpeg but its easy to follow Korok85 suggestion to use blender to adjust frame and length.