Android Getting Sound Levels

Hello there!

I'm a newbie in programming and I wanna build a sound recording application.

I have this code which is recording sound and puts a timestamp:

package com.tsop.tsp_recorder;

import android.R.layout;
import android.app.Activity;
import android.widget.HorizontalScrollView;
import android.widget.LinearLayout;
import android.os.Bundle;
import android.os.Environment;
import android.view.ViewGroup;
import android.widget.Button;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup.MarginLayoutParams;
import android.content.Context;
import android.util.Log;
import android.media.MediaRecorder;
import android.media.MediaPlayer;
import java.io.IOException;
import java.util.Calendar;


public class MainActivity extends Activity { 
  private static final String LOG_TAG = "AudioRecordTest";
  private static String mFileName = null;
  private RecordButton mRecordButton = null;
  private MediaRecorder mRecorder = null;
  private PlayButton mPlayButton = null;
  private MediaPlayer mPlayer = null;

private void onRecord(boolean start) {
  if (start) {
    startRecording(); 
  } else {
    stopRecording();
  }
}

private void onPlay(boolean start) {
  if (start) {
    startPlaying();
  } else {
    stopPlaying();
  }
}

private void startPlaying() {
  mPlayer = new MediaPlayer();
  try {
    mPlayer.setDataSource(mFileName);
    mPlayer.prepare();
    mPlayer.start();
  } catch (IOException e) {
    Log.e(LOG_TAG, "prepare() failed");
  }
}

private void stopPlaying() {
  mPlayer.release();
  mPlayer = null;
}

private void startRecording() {
  mRecorder = new MediaRecorder();
  mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
  mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
  mRecorder.setOutputFile(mFileName);
  mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);

  try {
    mRecorder.prepare();
  } catch (IOException e) {
    Log.e(LOG_TAG, "prepare() failed");
  }

  mRecorder.start();
}

private void stopRecording() {
  mRecorder.stop();
  mRecorder.release();
  mRecorder = null;
}

class RecordButton extends Button {
  boolean mStartRecording = true;

  OnClickListener clicker = new OnClickListener() {
    public void onClick(View v) {
      onRecord(mStartRecording);
      if (mStartRecording) {
        setText("Stop recording");
      } else {
        setText("Start recording");
      }
      mStartRecording = !mStartRecording;
    }
  };

  public RecordButton(Context ctx) {
    super(ctx);
    setText("Start recording");
    setOnClickListener(clicker);
  }
}

class PlayButton extends Button {
  boolean mStartPlaying = true;

  OnClickListener clicker = new OnClickListener() {
    public void onClick(View v) {
      onPlay(mStartPlaying);
      if (mStartPlaying) {
        setText("Stop playing");
      } else {
        setText("Start playing");
      }
      mStartPlaying = !mStartPlaying;
    }
  };

  public PlayButton(Context ctx) {
    super(ctx);
    setText("Start playing");
    setOnClickListener(clicker);
  }
}

public MainActivity() {
  theDate date = new theDate();
  String sDate = date.curDate();
  String sTime = date.curTime();
  mFileName = Environment.getExternalStorageDirectory().getAbsolutePath();
  mFileName += "/TSP_Recordings/Date_"+sDate+"_Time_"+sTime+".3gp";
}

@Override
public void onCreate(Bundle icicle) {
  super.onCreate(icicle);
  LinearLayout ll = new LinearLayout(this);
  mRecordButton = new RecordButton(this);
  ll.addView(mRecordButton,
  new LinearLayout.LayoutParams(
    ViewGroup.LayoutParams.WRAP_CONTENT,
    ViewGroup.LayoutParams.WRAP_CONTENT,
    0));
  mPlayButton = new PlayButton(this);
  ll.addView(mPlayButton,
    new LinearLayout.LayoutParams(
    ViewGroup.LayoutParams.WRAP_CONTENT,
    ViewGroup.LayoutParams.WRAP_CONTENT,
    0));
  setContentView(ll);
}

@Override
public void onPause() {
  super.onPause();
  if (mRecorder != null) {
    mRecorder.release();
    mRecorder = null;
  }
  if (mPlayer != null) {
    mPlayer.release();
    mPlayer = null;
  }
} 
}


package com.tsop.tsp_recorder;

import java.util.Calendar;

public class theDate {
  static Calendar c = Calendar.getInstance();

  public static String curDate() {
    int month = c.get(Calendar.MONTH) + 1;
    String sDate = c.get(Calendar.DAY_OF_MONTH) + "-" 
    + month
    + "-" + c.get(Calendar.YEAR);
    return sDate;
  }

  public static String curTime() {
    String sTime = c.get(Calendar.HOUR_OF_DAY) 
    + "-" + c.get(Calendar.MINUTE) + "-"
    + c.get(Calendar.SECOND);
    return sTime;
  }

  public static long duration() {
    long dur = c.getTimeInMillis();
    return dur;
  }
}

I need to change it and make it messure the sound levels. I'll use the getMaxAmplitude method, but this method returns only the last result, before it was called. I think I should use a loop, but the start method is capturing and encoding condinuously.

How can I get the current amplitude, for example in a period of 1 second, on my recording?

Thanks