video frames Extraction

hi i found an article here in this site about video frames extraction.
i em trying to run the source code given here..
i created a new project added the given C# code in it.
then i added the given reference " interop.dexterlib.dll" in it.

it gives an error about MediaDetClass.
Error   1
Interop type 'DexterLib.MediaDetClass' cannot be embedded. Use the applicable interface instead.


<pre lang="cs">using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;
using System.Data;
using System.Collections;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.IO;
using System.Threading;

using DexterLib;

namespace imageExtractor
{
    public class Form1 : System.Windows.Forms.Form
    {
        string fileName;           //used to save the movie file name
        string storagePath;        //used for the path where we save files
        MediaDetClass md;          //needed to extract pictures  =======================>>> here is the Errorrr
        static int counter = 0;    //to generate different file names
        float interval = 1.0f;     //default time interval
..
..
..
..
</pre>

i have skipped remaining code. just mentioning the area where errror has occured.
how to solv it i em not getting it.