title: OpenCV VideoCapture not read any video File in Windows 7 32bit
body: <p>i try to read .avi or .mpeg video file using VideoCapture class of OpenCV2.4.8 in C++ using QtCreator and CMake 2.8.12.1.
  Before built OpenCV, i download FFMPEG static version and put them into Program Files directory, i add their path into enviroments variable PATH, then i download K Lite Codec Pack Full, install it and only then i built OpenCV with CMAKE and mingw provide by Qt. After installation i add to PATH the right path of built OpenCV. 
  The stream from webcam works fine, but the stream from a video file doesn't work. I tried on Windows 7 32bit and Windows 8 64bit.
  Here is the code</p>
  
  <pre><code>#include &lt;opencv2/imgproc/imgproc.hpp&gt;
  #include &lt;opencv2/highgui/highgui.hpp&gt;
  #include &lt;opencv2/core/core.hpp&gt;
  #include "opencv2/opencv.hpp"
  cv::Mat img;
  cv::VideoCapture cap("Prova.avi");
  std::cerr &lt;&lt; cap.isOpened() &lt;&lt; std::endl;
  while(cap.read(img)){
      cv::imshow("Opencv", img);
      cv::waitKey(33);
  }
  </code></pre>
  
  <p>The same code works on Ubuntu 12.04 with the same version of OpenCV and with the ffmpeg build by myself.
  What is wrong?</p>