title: Capture only one thumbnail image from a video
body: <p>i am working to generate thumbnail images from a video. I am able to do it but i need only one thumbnail image from a video , but what i get is more than one images at different times of the video. I have used the following code to generate the thumbnails . Please suggest me what should i modify in the following code to get only one thumbnail from the middle portion of the video . The code i used is as follows ( I have used Xuggler ):</p>
  
  <pre><code>import java.awt.image.BufferedImage;
  import java.io.File;
  import java.io.IOException;
  import javax.imageio.ImageIO;
  import com.xuggle.mediatool.IMediaReader;
  import com.xuggle.mediatool.MediaListenerAdapter;
  import com.xuggle.mediatool.ToolFactory;
  import com.xuggle.mediatool.event.IVideoPictureEvent;
  import com.xuggle.xuggler.Global;
  
  public class Main {
  
      public static final double SECONDS_BETWEEN_FRAMES = 10;
      private static final String inputFilename = "D:\\k\\Knock On Wood Lesson.flv";
      private static final String outputFilePrefix = "D:\\pix\\";
  // The video stream index, used to ensure we display frames from one and
  // only one video stream from the media container.
      private static int mVideoStreamIndex = -1;
  // Time of last frame write
      private static long mLastPtsWrite = Global.NO_PTS;
      public static final long MICRO_SECONDS_BETWEEN_FRAMES =
              (long) (Global.DEFAULT_PTS_PER_SECOND * SECONDS_BETWEEN_FRAMES);
  
      public static void main(String[] args) {
          IMediaReader mediaReader = ToolFactory.makeReader(inputFilename);
          // stipulate that we want BufferedImages created in BGR 24bit color space
          mediaReader.setBufferedImageTypeToGenerate(BufferedImage.TYPE_3BYTE_BGR);
          mediaReader.addListener(new ImageSnapListener());
          // read out the contents of the media file and
          // dispatch events to the attached listener
          while (mediaReader.readPacket() == null);
      }
  
      private static class ImageSnapListener extends MediaListenerAdapter {
  
          public void onVideoPicture(IVideoPictureEvent event) {
              if (event.getStreamIndex() != mVideoStreamIndex) {
                  // if the selected video stream id is not yet set, go ahead an
                  // select this lucky video stream
                  if (mVideoStreamIndex == -1) {
                      mVideoStreamIndex = event.getStreamIndex();
                  } // no need to show frames from this video stream
                  else {
                      return;
                  }
              }
              // if uninitialized, back date mLastPtsWrite to get the very first frame
              if (mLastPtsWrite == Global.NO_PTS) {
                  mLastPtsWrite = event.getTimeStamp() - MICRO_SECONDS_BETWEEN_FRAMES;
              }
              // if it's time to write the next frame
              if (event.getTimeStamp() - mLastPtsWrite
                      &gt;= MICRO_SECONDS_BETWEEN_FRAMES) {
                  String outputFilename = dumpImageToFile(event.getImage());
                  // indicate file written
                  double seconds = ((double) event.getTimeStamp())
                          / Global.DEFAULT_PTS_PER_SECOND;
                  System.out.printf("at elapsed time of %6.3f seconds wrote: %s\n",
                          seconds, outputFilename);
                  // update last write time
                  mLastPtsWrite += MICRO_SECONDS_BETWEEN_FRAMES;
              }
          }
  
          private String dumpImageToFile(BufferedImage image) {
              try {
                  String outputFilename = outputFilePrefix
                          + System.currentTimeMillis() + ".png";
                  ImageIO.write(image, "png", new File(outputFilename));
                  return outputFilename;
              } catch (IOException e) {
                  e.printStackTrace();
                  return null;
              }
          }
      }
  }
  </code></pre>