XUGGLE ERROR: Exception in thread "main" java.lang.NoClassDefFoundError: org/slf4j/LoggerFactory

I am trying to execute the following code:

import com.xuggle.mediatool.IMediaReader;
import com.xuggle.mediatool.IMediaWriter;
import com.xuggle.mediatool.ToolFactory;
public class vidcon {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        IMediaReader reader = ToolFactory.makeReader("test.m4v");
        IMediaWriter writer = ToolFactory.makeWriter("out.flv");

        reader.addListener(writer);
        while(reader.readPacket() == null)
            ;
    }
}

But it is is giving me this error:

Exception in thread "main" java.lang.NoClassDefFoundError: org/slf4j/LoggerFactory
    at com.xuggle.ferry.JNILibrary.<clinit>(JNILibrary.java:42)
    at com.xuggle.ferry.FerryJNI.<clinit>(FerryJNI.java:14)
    at com.xuggle.ferry.Ferry.<clinit>(Ferry.java:25)
    at com.xuggle.xuggler.XugglerJNI.<clinit>(XugglerJNI.java:19)
    at com.xuggle.xuggler.IContainer.<clinit>(IContainer.java:1622)
    at com.xuggle.mediatool.MediaReader.<init>(MediaReader.java:137)
    at com.xuggle.mediatool.ToolFactory.makeReader(ToolFactory.java:77)
    at vidcon.main(vidcon.java:11)
Caused by: java.lang.ClassNotFoundException: org.slf4j.LoggerFactory
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    ... 8 more

I have added SLF4J to my referenced libraries, but have no idea why this is not working.

Running on WIN 7, tried in eclipse and netbeans

Any idea?

Download SLF4J and put the slf4j-api-1.7.2.jar file onto your class path.