animation gif from mp4 files

agif

#!/usr/bin/env ruby

def run(cmd)
  puts "$ #{cmd}"
  `#{cmd}`
end

if ARGV.size < 1 || /.mp4$/i !~ ARGV[0]
    puts "usage: agif <something.mp4>"
    exit 0
end

VIDEO_FILE = ARGV[0]
GIF_FILE   = ARGV[0].sub(/\.mp4$/i, ".gif")
TMP_DIR    = ".tmp"
RATE       = 4

# 1. clean up

if Dir.exist?(TMP_DIR)
    `rm -rf #{TMP_DIR}`
end
`mkdir -p #{TMP_DIR}`

# 2. exec

run "ffmpeg -i #{VIDEO_FILE} -r #{RATE} -f image2 #{TMP_DIR}/%05d.jpg"

# 3. clean up
files=`find #{TMP_DIR} -type f -name '*.jpg' | xargs echo`.chomp
run "convert #{files} #{GIF_FILE}"

`rm -rf #{TMP_DIR}`