title: Get specific frames using EmguCv
body: <p>I have a EmguCv.Capture in 'Movie' class.
  I want to create a function that get a frame number and return this frame, like:</p>
  
  <pre><code>using Emgu.CV;
  using Emgu.CV.Structure;
  
  Class Movie
  {
     private Capture capture;
     public Movie(string FileName)
     {
       capture=new Capture(FileName);
       ...
     }
     public Image&lt;Bgr, byte&gt; GetFrame(int FrameNum)
     {
      //return the FrameNum frame
     }
  }
  </code></pre>
  
  <p>I need to do that as quickly as possible.
  Any ideas?</p>