title: OpenCV Camera Calibration
body: <p>i'm using Camera calibration With OpenCV tutorial (<a href="http://docs.opencv.org/doc/tutorials/calib3d/camera_calibration/camera_calibration.html" rel="nofollow">http://docs.opencv.org/doc/tutorials/calib3d/camera_calibration/camera_calibration.html</a>). When I use .mp4 video file as input, my program fails and gives this error:
  Parsing error (): Valid XML should start with '') in icvXMLParse, file ........\opencv\modules\core\src\persistence.cpp, line 2252</p>
  
  <p>Could anyone please tell me what i'm doing wrong?</p>