High quality video to gif encoding using ffmpeg. From http://blog.pkh.me/p/21-high-quality-gif-with-ffmpeg.html

gifenc.sh

#!/bin/sh

# http://blog.pkh.me/p/21-high-quality-gif-with-ffmpeg.html
# usage: ./gifenc.sh [input].mov [output].gif

palette="palette.png"

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

ffmpeg -v warning -i $1 -vf "$filters,palettegen" -y $palette
ffmpeg -v warning -i $1 -i $palette -lavfi "$filters [x]; [x][1:v] paletteuse" -y $2