fadeinout.rb

#!/usr/bin/env ruby

unless ARGV[0] && ARGV[1]
  puts "Usage: fadeinout INPUT OUTPUT [DURATION]" 
  exit
end

if ARGV[2]
  duration = ARGV[2].to_f
else
  duration = 3
end

`ffmpeg -i #{ARGV[0]} -vf "fade=t=in:st=0:d=#{duration},fade=t=out:st=101:d=3" -af "afade=t=in:st=0:d=#{duration},afade=t=out:st=101:d=3" #{ARGV[1]}`