Shell script
Convert to AVIF Programmatically

This shell script converts JPG and PNG images into AVIF and WebP using ffmpeg and Google’s WebP encoder.

# macOS
brew install ffmpeg webp

# Arch Linux
sudo pacman -S ffmpeg webp

AVIF, besides producing smaller file sizes, they make optically better images than cwebp. No artifacts, sharper, and more accurate colors.

#!/bin/sh
set -o noglob
IFS=$'\n'

images=$(find ~/imgs -type f -name *.png -o -name *.jpg)

for img in $images; do
  avif_out=$img.avif
  webp_out=$img.webp

  if [ $img -nt $avif_out ]; then
    ffmpeg -i "$img" -c:v libsvtav1 -svtav1-params avif=1 "$img" "$avif_out"
  fi

  if [ $img -nt $webp_out ]; then
    cwebp $img -o $webp_out
  fi
done

The images end up with the original extension plus the modern one (e.g. foo.png.avif) because I need those file names to Conditionally Serve the Optimal Image Format with Nginx.