Android : Need To Record Audio - Video Recording Files In 3gp / Mp4 Format

I need to record audio and video files in 3gp/mp4 format at the same file and same time.

When i run my application file is created with videofile.3gp but video does not record in sd card on the emulator.please let me clear one thing does video records on the emulator? if i run this code on android supported device do these error clear.
Please help me. I am new to this topic.please find the code and errors below.

package com.video;

* @copy Rights
* audio.java
* sample code for Eminosoft Developerworks Article
* Android development Team
* www.eminosoft.cm

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import android.app.Activity;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.provider.Settings;
import android.util.Log;
import android.view.View;
import android.widget.Button;

public class video extends Activity {

public MediaRecorder mrec = null;
private Button startRecording = null;
private Button stopRecording = null;
private static final String TAG = "SoundRecordingDemo";
File audiofile;
File video;
private MediaPlayer mMediaPlayer;}