RuntimeException: start failed in AudioRecording
<p>Ham doing audio recording in my project. The problem is ham getting runtime exception in my project.</p>

<pre><code> 12-02 14:58:47.145: E/AndroidRuntime(22802): FATAL EXCEPTION: main
12-02 14:58:47.145: E/AndroidRuntime(22802): java.lang.RuntimeException: start failed.
12-02 14:58:47.145: E/AndroidRuntime(22802):    at android.media.MediaRecorder.start(Native Method)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at com.android.audio.AudioRecordActivity.startRecording(AudioRecordActivity.java:80)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at com.android.audio.AudioRecordActivity.access$1(AudioRecordActivity.java:67)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at com.android.audio.AudioRecordActivity$3.onClick(AudioRecordActivity.java:138)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at android.view.View.performClick(View.java:3460)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at android.view.View$PerformClick.run(View.java:13955)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at android.os.Handler.handleCallback(Handler.java:605)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at android.os.Handler.dispatchMessage(Handler.java:92)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at android.os.Looper.loop(Looper.java:137)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at android.app.ActivityThread.main(ActivityThread.java:4340)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at java.lang.reflect.Method.invokeNative(Native Method)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at java.lang.reflect.Method.invoke(Method.java:511)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
12-02 14:58:47.145: E/AndroidRuntime(22802):    at dalvik.system.NativeStart.main(Native Method)
</code></pre>

<p>when I debug and I'm getting the error in this particular line of code:   </p>

<p>recorder.start();</p>

<p>My source code is as follows</p>

<pre><code> package com.android.audio;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import org.apache.http.util.ByteArrayBuffer;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.ContentValues;
import android.content.DialogInterface;
import android.content.Intent;
import android.media.MediaRecorder;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.widget.Button;

public class AudioRecordActivity extends Activity
{
    private static final String AUDIO_RECORDER_FILE_EXT_3GP = ".3gp";
    private static final String AUDIO_RECORDER_FILE_EXT_MP4 = ".mp4";
    private static final String AUDIO_RECORDER_FOLDER = "AudioRecorder";
    File file;
    private MediaRecorder recorder = null;
    private int currentFormat = 0;
    private int output_formats[] = { MediaRecorder.OutputFormat.MPEG_4, MediaRecorder.OutputFormat.THREE_GPP };
    private String file_exts[] = { AUDIO_RECORDER_FILE_EXT_MP4, AUDIO_RECORDER_FILE_EXT_3GP }; 

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    setButtonHandlers();
    enableButtons(false);
    setFormatButtonCaption();
}

    private void setButtonHandlers() {
            ((Button)findViewById(R.id.btnStart)).setOnClickListener(btnClick);
    ((Button)findViewById(R.id.btnStop)).setOnClickListener(btnClick);
    ((Button)findViewById(R.id.btnFormat)).setOnClickListener(btnClick);
    }

    private void enableButton(int id,boolean isEnable){
            ((Button)findViewById(id)).setEnabled(isEnable);
    }

    private void enableButtons(boolean isRecording) {
            enableButton(R.id.btnStart,!isRecording);
            enableButton(R.id.btnFormat,!isRecording);
            enableButton(R.id.btnStop,isRecording);
    }

    private void setFormatButtonCaption(){
            ((Button)findViewById(R.id.btnFormat)).setText(getString(R.string.audio_format) + " (" + file_exts[currentFormat] + ")");
    }

    private String getFilename(){

            String filepath = Environment.getExternalStorageDirectory().getPath();
            file = new File(filepath,AUDIO_RECORDER_FOLDER);

            if(!file.exists()){
                    file.mkdirs();
            }




            return (file.getAbsolutePath() + "/" + System.currentTimeMillis() + file_exts[currentFormat]);
    }


    private void startRecording(){
            recorder = new MediaRecorder();

            recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
            recorder.setOutputFormat(output_formats[currentFormat]);
            recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
            recorder.setOutputFile(getFilename());

            recorder.setOnErrorListener(errorListener);
            recorder.setOnInfoListener(infoListener);

            try {
                    recorder.prepare();
                    recorder.start();
            } catch (IllegalStateException e) {
                    e.printStackTrace();
            } catch (IOException e) {
                    e.printStackTrace();
            }
    }

    private void stopRecording(){
            if(null != recorder){
                    recorder.stop();
                    recorder.reset();
                    recorder.release();

                    recorder = null;
            }
    }

    private void displayFormatDialog(){
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            String formats[] = {"MPEG 4", "3GPP"};

            builder.setTitle(getString(R.string.choose_format_title))
                       .setSingleChoiceItems(formats, currentFormat, new DialogInterface.OnClickListener() {

                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                    currentFormat = which;
                                    setFormatButtonCaption();

                                    dialog.dismiss();
                            }
                       })
                       .show();
    }

    private MediaRecorder.OnErrorListener errorListener = new MediaRecorder.OnErrorListener() {
            @Override
            public void onError(MediaRecorder mr, int what, int extra) {
                    AppLog.logString("Error: " + what + ", " + extra);
            }
    };

    private MediaRecorder.OnInfoListener infoListener = new MediaRecorder.OnInfoListener() {
            @Override
            public void onInfo(MediaRecorder mr, int what, int extra) {
                    AppLog.logString("Warning: " + what + ", " + extra);
            }
    };

private View.OnClickListener btnClick = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                    switch(v.getId()){
                            case R.id.btnStart:{
                                    AppLog.logString("Start Recording");

                                    enableButtons(true);
                                    startRecording();

                                    break;
                            }
                            case R.id.btnStop:{
                                    AppLog.logString("Start Recording");

                                    enableButtons(false);
                                    stopRecording();

                                    break;
                            }
                            case R.id.btnFormat:{
                                    displayFormatDialog();

                                    break;
                            }
                    }
            }
    }; 


}
</code></pre>
