title: cv2.VideoWriter: Asks for a tuple as Size argument, then rejects it
body: <p>I'm using OpenCV 4.0 and Python 3.7 to create a timelapse video.</p>
  
  <p>When constructing a VideoWriter object, the documentation says the Size argument should be a tuple. </p>
  
  <p>When I give it a tuple it rejects it. When I try to replace it with something else, it won't accept it because it says the argument isn't a tuple.</p>
  
  <p>When Size not a tuple:</p>
  
  <pre><code>out = cv2.VideoWriter('project.avi', 1482049860, 30, height, width)
  SystemError: new style getargs format but argument is not a tuple
  </code></pre>
  
  <p>When I changed Size to a tuple:</p>
  
  <pre><code>out = cv2.VideoWriter('project.avi', 1482049860, 30, (height, width))
  TypeError: must be real number, not tuple
  </code></pre>
  
  <p>I just want to create a simple cv2.VideoWriter object.</p>