Make a reasonable-quality GIF from a video clip

mkgif

#!/usr/bin/env bash

set -Eeuo pipefail

if [[ $# == 0 ]]; then
  echo >&2 "movie filename and output filename is required"
  exit 1
fi

input_file="$1"
output_file="$2"
start_and_duration=""

if [[ $# == 4 ]]; then
  start_time=$3
  duration=$4
  start_and_duration="-ss $start_time -t $duration"
fi

palette="/tmp/palette.png"

filters="fps=15,scale=480:-1:flags=lanczos"

ffmpeg -v warning $start_and_duration -i "$input_file" -vf "$filters,palettegen" -y $palette
ffmpeg -v warning $start_and_duration -i "$input_file" -i $palette -lavfi "$filters [x]; [x][1:v] paletteuse" -y "$output_file"