Android Visualizer

So I am trying to use the audio visualizer to play along with the audio. But i am getting an error. The listview for the songs is coming out fine,but after that when I click on a song the app crahses. Heres the logcat:

01-22 07:58:42.710    8140-8140/app.my.com.wave E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{http://ift.tt/1CfPCrL}: java.lang.NullPointerException
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2118)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2143)
        at android.app.ActivityThread.access$700(ActivityThread.java:140)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1237)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:174)
        at android.app.ActivityThread.main(ActivityThread.java:4952)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)
        at dalvik.system.NativeStart.main(Native Method)
 Caused by: java.lang.NullPointerException
        at app.my.com.wave.V.onCreate(V.java:28)
        at android.app.Activity.performCreate(Activity.java:5188)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
        at 

Heres the V class for the visualizer:

package app.my.com.wave;

 import android.content.Intent;
 import android.media.MediaPlayer;
 import android.media.audiofx.Visualizer;
 import android.support.v7.app.ActionBarActivity;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuItem;
 import java.io.IOException;


public class V extends ActionBarActivity {
private MediaPlayer mPlayer;
private byte[] mBytes;
private byte[] mFFTBytes;
private Visualizer mVisualizer;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_v);

    Intent i = getIntent();
    String path = i.getStringExtra("path");

    try {
        mPlayer.setDataSource(path);
        mPlayer.prepare();

    } catch (IllegalArgumentException e) {
        e.printStackTrace();
    } catch (IllegalStateException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    mPlayer.start();
    mPlayer.setLooping(false);
    mVisualizer = new Visualizer(mPlayer.getAudioSessionId());
    mVisualizer.setCaptureSize(Visualizer.getCaptureSizeRange()[1]);

    Visualizer.OnDataCaptureListener captureListener = new Visualizer.OnDataCaptureListener() {
        @Override
        public void onWaveFormDataCapture(Visualizer visualizer, byte[] bytes,
                                          int samplingRate) {
            System.out.println("onWaveFormDataCapture");
        }

        @Override
        public void onFftDataCapture(Visualizer visualizer, byte[] bytes,
                                     int samplingRate) {
            System.out.println("onFftDataCapture");
        }
    };

    mVisualizer.setDataCaptureListener(captureListener,
            Visualizer.getMaxCaptureRate() / 2, true, false);

    mVisualizer.setEnabled(true);
    mPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mediaPlayer) {
            mVisualizer.setEnabled(false);
        }
    });
}}

So the app crashes once I press a song. Please help me out and thanks in advance.