Convert a video to GIF

gif

#!/bin/bash
set -e

if [ "$1" = "" ] || [ "$1" = "-h" ] || [ "$1" = "-help" ] || [ "$1" = "--help" ]; then
  echo "usage: ${0##*/} <video-input-file> [<gif-output-file>]" >&2
  echo "  if <gif-output-file> is not provided, <video-input-file> with" >&2
  echo "  filename extension replaced by \".gif\" is used" >&2
  exit 1
fi

infile=$1
outfile=$2

if [ "$outfile" = "" ]; then
  outfile=$(echo "$infile" | sed -E 's/\.[^\.]+$/.gif/g')
fi

if [ -e "$outfile" ] && [ -d ~/.Trash ]; then
  mv -f "$outfile" ~/.Trash/"$(basename "$outfile")"
fi

if [ -z $TMPDIR ]; then
  TMPDIR=/tmp
fi
palette="${TMPDIR}/palette.png"
echo "palette: $palette"

filters="fps=5,unsharp=luma_msize_x=3:luma_msize_y=3:luma_amount=1.0,scale=800:-1:flags=lanczos"
paletteops="stats_mode=diff"
paletteops=""

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

if (which gifsicle >/dev/null); then
  gifsicle --optimize=3 --output "$outfile" "$outfile"
fi