Android MediaMetadataRetriever get frame using FFmpegMediaMetadataRetriever

Question

Can someone please help me about my problem regarding getting current frame from videoview using rtsp data source. I have followed this tutorial from this blog. In this code wherein the bitmap image will be displayed when the user decides to capture the current frame from the videoview:

Bitmap bmFrame = mediaMetadataRetriever
  .getFrameAtTime(currentPosition * 1000); //unit in microsecond

if(bmFrame == null){
 Toast.makeText(MainActivity.this, 
   "bmFrame == null!", 
   Toast.LENGTH_LONG).show();
}else{
 AlertDialog.Builder myCaptureDialog = 
   new AlertDialog.Builder(MainActivity.this);
 ImageView capturedImageView = new ImageView(MainActivity.this);
 capturedImageView.setImageBitmap(bmFrame);
 LayoutParams capturedImageViewLayoutParams = 
   new LayoutParams(LayoutParams.WRAP_CONTENT, 
     LayoutParams.WRAP_CONTENT);
 capturedImageView.setLayoutParams(capturedImageViewLayoutParams);

 myCaptureDialog.setView(capturedImageView);
 myCaptureDialog.show();
}

I get a null value. After researching for many hours, many said on that FFmpegMediaMetadataRetriever library from this link can handle rtsp protocol. How would I apply this library? I already downloaded it, imported on eclipse, and added it on as a library. It seems that when I call this class library:

FFmpegMediaMetadataRetriever mMediaMetadataRetriever = new FFmpegMediaMetadataRetriever();

I get an error which is java.lang.ExceptionInInitializeError. Am I on the right track? Can someone guide me on this please.