title: OpenCV videowrite doesn't write video
body: <p>I used the following page from <code>OpenCV 3.0.0</code> tutorial: <a href="http://opencv-python-tutroals.readthedocs.org/en/latest/py_tutorials/py_gui/py_video_display/py_video_display.html#display-video" rel="noreferrer">Tutorial in docs</a></p>
  <p>When I tried to use the example that saves videos, it doesn't work.</p>
  <p>It displays the content from the webcam, and also creates a file called <code>output.avi</code>, but when I checked the size of <code>ouput.avi</code>, it was zero bytes.</p>
  <p>I also tried using different codecs, like <code>YUY2</code>.</p>
  <p>I use <code>Python 2.7.8</code> and <code>OpenCV 3.0.0</code>
  and <code>Windows 8.1</code></p>