Make gifs from videos

gif.sh

#!/bin/bash

set -euo pipefail

if [ ! "$1" ]; then
    echo "Usage: $0 start_time duration input"
    exit 1
fi

start_time=$1
duration=$2
input=$3
scale=720
output="$3_$1_$2_$scale.gif"
fps=12
log_level="verbose"

filters="[0:v] fps=$fps,scale=$scale:-1:flags=lanczos,split [a][b];[a] palettegen [p];[b][p] paletteuse"

ffmpeg -v "$log_level" -ss "$start_time" -t "$duration" -i "$input" -filter_complex "$filters" "$output"

echo "$output"

# Useful optimisation: gifsicle -O3 --lossy=30 -o output.gif input.gif.