37C3-FFmpeg-Dithering

A simple CLI command wrapper for FFmpeg written in Python to apply dithering algorithms and color palettes to images and videos. It can be used to turn almost any type of media (supported by FFmpeg) into the style of '37C3: Unlocked'.

https://events.ccc.de/2023/11/27/37c3-hat-die-haare-schoen/

Prerequisites

• Clone this repository (you'll need the 'palette' folder and the 'dither-this.py' file)
• Python 3 installed and added to PATH
• FFmpeg installed and added to PATH

Usage

Simply call the 'dither-this.py' file from the command line or run it without any arguments. When running the script without any arguments, it will look for a file called 'input.mp4' and process it with the default values.

By passing the '-h' or '--help' flag you can list all available options.

n0c@box:~$ dither-this.py --help

usage: dither-this.py [-h] [-i INPUT] [-p FINAL_PALETTE] [-pi INTERMEDIATE_PALETTE] [-fps FRAMERATE] [-s SIZE] [-b BRIGHTNESS] [-c CONTRAST] [-d DITHER] [-bs BAYER_SCALE]
                      [-loop LOOP] [-o OUTPUT]

Convert a video/image to a dithered version in the stlye of '37C3: Unlocked' using FFmpeg.

options:
  -h, --help            show this help message and exit
  -i INPUT, --input INPUT
                        Input file
  -p FINAL_PALETTE, --final_palette FINAL_PALETTE
                        Final color palette
  -pi INTERMEDIATE_PALETTE, --intermediate_palette INTERMEDIATE_PALETTE
                        Intermediate color palette
  -fps FRAMERATE, --framerate FRAMERATE
                        Frame rate
  -s SIZE, --size SIZE  Width of the output GIF, aspect ratio is preserved
  -b BRIGHTNESS, --brightness BRIGHTNESS
                        Brightness, -1 to 1, with 0 being the default value
  -c CONTRAST, --contrast CONTRAST
                        Contrast, 0 to 2, with 1 being the default value
  -d DITHER, --dither DITHER
                        Dither algorithm: bayer, heckbert, floyd_steinberg, sierra2, sierra2_4a
  -bs BAYER_SCALE, --bayer_scale BAYER_SCALE
                        Bayer scale: 0 to 2
  -loop LOOP, --loop LOOP
                        Loop
  -o OUTPUT, --output OUTPUT
                        Output filename

Examples (Image to Image)

Default values with resizing to 256px width:

n0c@box:~$ dither-this.py -i lenna.jpg -s 256 -o lenna-default.jpg

Alternative dithering algorithm:

n0c@box:~$ dither-this.py -i lenna.jpg -s 256 -d floyd_steinberg -o lenna-floyd_steinberg.jpg

Alternative dithering algorithm with brightness/contrast fix:

n0c@box:~$ dither-this.py -i lenna.jpg -s 256 -d floyd_steinberg -b -0.3 -c 1.3 -o lenna-floyd_steinberg-fix.jpg

Examples (Video / GIF)

Video to GIF:

n0c@box:~$ dither-this.py -i input.mp4 -s 256 -o dither-video.gif

Using the 'floyd_steinberg' dithering algorithm:

n0c@box:~$ dither-this.py -i input.mp4 -d floyd_steinberg -o output.gif

Reducing the color palette before applying the dithering algorithm (intermediate palette):

n0c@box:~$ dither-this.py -i input.mp4 -pi palette/palette-5-shades-of-gray-alpha.png -o output.gif

Using a different color palette for the final output:

n0c@box:~$ dither-this.py -i input.mp4 -p palette/palette-5-shades-of-gray-alpha.png -o output.gif

License

GNU GPLv3

Well, it's just a wrapper for a great piece of software doing the hard work (FFmpeg) and an experiment for the lulz. Do whatever you want with this python snippet, don't blame me and share any improvements and results you make!