title: Playing local files with HTML5
body: <p>Is it possible to play a video file which users have stored locally on their computer on a website? The path of the file is not known to me, I want the users to choose the file with a "choose file" dialog. </p>
  
  <p>The goal is to show overlays over the actual video files, but usually the video files will be too large to let the users upload them, such that I could process them on the server. So, I want the user to select the file from the local computer, directly play it with HTML5 in the browser and generate the overlays with Javascript.</p>