There's a simple way to do this in ffmpeg using this command - 'ffmpeg -i Input_1280x720.mp4 -f lavfi -i color=gray:s=1280x720 -f lavfi -i color=black:s=1280x720 -f lavfi -i color=white:s=1280x720 -filter_complex threshold output.mp4' - which gives us this:
Although I like this - its not quite what I was looking for . So I looked for some alternative way using ffmpeg to create dither but none of the methods I found gave me that look and feel . Then I thought well could I just convert the video to stills and use an old format like pbm and researching this I found that the netpbm library ( find netpbm page and links here ) has a function for creating atkinson like dither.
Most linux distros come with the netpbm library and that gives us different ways of dithering an image but the one I was most interested in - pamditherbw ( which has the setting for Atkinson dithering) didn't seem to be included which sent me down a rabbit hole of finding out why . To get this function you have to uninstall the netpbm that comes with your distro then download the deb file from here and carefully follow error messages that the installing with gdebi process throws up ( there are a couple of packages that need to be uninstalled and another that needs to be installed as well as the netpbm package ) - I know this sounds a little vaguer than I usually write but its easy enough when you see the process and follow the prompts.
So having that installed I could now run the script I wanted to run which gives me this, best viewed full screen ( I'll post the script at the end )
This is the script : caveats - you must remember to add file extension when answering 'what do you want to name the output file' ie mp4 - if using a different codec other than h264 you may wish to alter the ffmpeg statement at the end . It creates a lot of files when its working , so you might want to use a scratch disk ( I did a fifty minute video which created 80000 plus files here but it does clean up after itself ie removes the stills before exiting.
#!/bin/bash
#to get pam ditherbw to work uninstall pkgmanagers version of netpbm and download and from here https://sourceforge.net/projects/netpbm/files/
#more info on pamditherbw here http://netpbm.sourceforge.net/doc/pamditherbw.html
echo -n "File to work on ? : "
read n
echo -n "What do you want to name output file ? : "
read z
echo -n "Framerate as a number between 1 and 30 ? : "
read m
echo -n "crf value for final video ? : "
read o
# convert to pgm
ffmpeg -i $n -vf fps=$m image-%05d.pgm
i=0
find . -type f -name '*.pgm'|while read filename; do echo ${filename} ;
((i++))
# try different random seeds
pamditherbw -atkinson -randomseed 8 ${filename} > $i.pam ;
mogrify -format pbm $i.pam
mv "$i.pbm" "$(basename "${filename}" .pgm).pbm"
rm $i.pam
done
rm *.pam
rm *.pgm
ffmpeg -i image-%05d.pbm -vcodec libx264 -r $m -crf $o -pix_fmt yuv420p $z
#ffmpeg -i image-%05d.pbm -r $m -c:v hevc -b:v 2M $z
rm *.pbm
#ffmpeg -r $m -i %d.jpg -i $n -map 0:0 -map 1:1 -c:a copy -c:v libx264 -tune stillimage -crf $o -r 24 lol.mp4
