how to convert bytes(or String) to 3gp file??

hello.

i'm coding an App. which records the voice(voice recorder) , converts it to array of bytes then Encodes it to base64 .

so i decode the base64 file to normal String or bytes.

now i need to convert normal String(or bytes) variable to a voice file.

summary :

1_record a voice

2_convert to arrays of byte

3_encoded to base64

4_decode the arrays of byte

5_convert it to a playable sound file

here is my code :

PHP Code:

protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      
      text = (TextView) findViewById(R.id.text1);
      // store it to sd card
      outputFile = Environment.getExternalStorageDirectory().
                  getAbsolutePath() + "/recordfile.3gpp";

      myRecorder = new MediaRecorder();
      myRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
      myRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
      myRecorder.setAudioEncoder(MediaRecorder.OutputFormat.AMR_NB);
      myRecorder.setOutputFile(outputFile);
      
      startBtn = (Button)findViewById(R.id.start);
      startBtn.setOnClickListener(new OnClickListener() {
                
                @Override
                public void onClick(View v) {
                        // TODO Auto-generated method stub
                        start(v);
                }
      });
      
      stopBtn = (Button)findViewById(R.id.stop);
      stopBtn.setOnClickListener(new OnClickListener() {
                
                @Override
                public void onClick(View v) {
                        // TODO Auto-generated method stub
                        try {
                                stop(v);
                        } catch (IOException e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                        }
                }
      });
      
      playBtn = (Button)findViewById(R.id.play);
      playBtn.setOnClickListener(new OnClickListener() {
                
                @Override
                public void onClick(View v) {
                        // TODO Auto-generated method stub
                                play(v);        
                }
      });
      
      stopPlayBtn = (Button)findViewById(R.id.stopPlay);
      stopPlayBtn.setOnClickListener(new OnClickListener() {
                
                @Override
                public void onClick(View v) {
                        // TODO Auto-generated method stub
                        stopPlay(v);
                }
      });
   }

   public void start(View view){
           try {
          myRecorder.prepare();
          myRecorder.start();
       } catch (IllegalStateException e) {
          // start:it is called before prepare()
          // prepare: it is called after start() or before setOutputFormat() 
          e.printStackTrace();
       } catch (IOException e) {
           // prepare() fails
           e.printStackTrace();
        }
           
       text.setText("Recording Point: Recording");
       startBtn.setEnabled(false);
       stopBtn.setEnabled(true);
       
       Toast.makeText(getApplicationContext(), "Start recording...", 
                   Toast.LENGTH_SHORT).show();
   }
   String encoded;
   File file ;
   public void stop(View view) throws IOException{
           
           try {
              myRecorder.stop();
              myRecorder.release();
              myRecorder  = null;
             // file = new File(Environment.getExternalStorageDirectory() + "/recordfile.3gpp");
                
                
                FileInputStream in=new FileInputStream(file=new File(outputFile+"/recordfile.3gp"));
                byte fileContent[] = new byte[(int)file.length()];
                
                in.read(fileContent,0,fileContent.length);
                
             encoded = Base64.encodeToString(fileContent,0);                                       
         //  Utilities.log("~~~~~~~~ Encoded: ", encoded);
              
              
              stopBtn.setEnabled(false);
              playBtn.setEnabled(true);
              text.setText("Recording Point: Stop recording");
              
              Toast.makeText(getApplicationContext(), "Stop recording...",
                          Toast.LENGTH_SHORT).show();
           } catch (IllegalStateException e) {
                        //  it is called before start()
                        e.printStackTrace();
           } catch (RuntimeException e) {
                        // no valid audio/video data has been received
                        e.printStackTrace();
           }
   }
  
   public void play(View view) {
           try{
                   myPlayer = new MediaPlayer();
                   
                   FileOutputStream out=new FileOutputStream(outputFile+"/decoded.3gp");
                   byte[] decoded = Base64.decode(encoded, 0);
                   
                   out.write(decoded);
                   out.close();
                   myPlayer.setDataSource(outputFile+"/decoded.3gp");
                   myPlayer.prepare();
                   myPlayer.start();
                   
                   playBtn.setEnabled(false);
                   stopPlayBtn.setEnabled(true);
                   text.setText("Recording Point: Playing");
                   
                   Toast.makeText(getApplicationContext(), "Start play the recording...", 
                                   Toast.LENGTH_SHORT).show();
           } catch (Exception e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }
   }

the output: records the voice but not playing. and it makes a file recordfile.3gp on SDcard which it play from sdcard corectly....

the output should be :

records the voice and playes it. make two files :recordfile.3gp and decoded.3gp

dosen't make the secode file??!!!