title: Tool to glue dozen of PNG into video
body: <p>I have made nearly 20 PNG screen captures. I wish to glue them into video. Could you recommend a tool?</p>
  
  <p>Better if that would be smooth change from one picture to another, like tween motion in Flash.</p>
  
  <p>Using actual flash is not an option. Because tool must be free and run on linux.</p>