.zshrc

gifify() {
  if [[ -n "$1" ]]; then
    if [[ $2 == '--good' ]]; then
      ffmpeg -i $1 -r 10 -vcodec png out-static-%05d.png
      time convert -verbose +dither -layers Optimize -resize 600x600\> out-static*.png  GIF:- | gifsicle --colors 128 --delay=5 --loop --optimize=3 --multifile - > $1.gif
      rm out-static*.png
    else
      ffmpeg -i $1 -s 600x400 -pix_fmt rgb24 -r 10 -f gif - | gifsicle --optimize=3 --delay=3 > $1.gif
    fi
  else
    echo "proper usage: gifify <input_movie.mov>. You DO need to include extension."
  fi
}

Install.sh

brew install ffmpeg
brew tap phinze/homebrew-cask
brew install brew-cask
brew cask install x-quartz
open /usr/local/Cellar/x-quartz/2.7.4/XQuartz.pkg
# click through the stuff
brew install gifsicle
brew install imagemagick

# I had a weird problem with Convert/imagemagick where I had to do:
ln -s /usr/local/Cellar/libtool/2.4.2/lib/libltdl.7.dylib libltdl.7.dylib
# But hopefully you don't have to

usage.sh

# Take screencast using Quicktime. Export as high quality as possible.

gifify screencap.mov
gifify screencap.mov --good

Apparently for install just needs
brew install ffmpeg gifsicle imagemagick