Android MediaRecorder Audio

MainActivity.java

package net.pablophg.mediatest;

import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Intent;
import android.media.MediaRecorder;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Toast;

import java.io.File;
import java.io.IOException;


public class MainActivity extends ActionBarActivity {

    MediaRecorder recorder;
    File audiofile = null;
    private static final String TAG = "GrabandoActivity";
    private View btnStart;
    private View btnStop;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btnStart = findViewById(R.id.buttonStart);
        btnStop = findViewById(R.id.buttonStop);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    public void startRecording(View view) throws IOException {
        btnStart.setEnabled(false);
        btnStop.setEnabled(true);

        File ejemploDir = Environment.getExternalStorageDirectory();
        try {
            audiofile = File.createTempFile("sound", ".3gp", ejemploDir);
            Log.e(TAG, "archivo creado");
        }catch (IOException e) {
            Log.e(TAG, "error acceso a sdcard");
            return;
        }

        recorder = new MediaRecorder();
        recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
        recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        recorder.setOutputFile(audiofile.getAbsolutePath());
        Log.e("setOutputFile", "called");
        recorder.prepare();
        recorder.start();
    }

    public void stopRecording(View view) {
        btnStart.setEnabled(true);
        btnStop.setEnabled(false);

        recorder.stop();
        recorder.release();

        addRecordingToMediaLibrary();
    }

    private void addRecordingToMediaLibrary() {
        ContentValues values = new ContentValues(4);
        long current = System.currentTimeMillis();
        values.put(MediaStore.Audio.Media.TITLE, "audio" + audiofile.getName());
        values.put(MediaStore.Audio.Media.DATE_ADDED, (int) (current / 1000));
        values.put(MediaStore.Audio.Media.MIME_TYPE, "audio/3gpp");
        values.put(MediaStore.Audio.Media.DATA, audiofile.getAbsolutePath());
        ContentResolver contentResolver = getContentResolver();
        Uri base = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
        Uri newUri = contentResolver.insert(base, values);
        sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, newUri));
        Toast.makeText(this, "Añadido el fichero " + newUri, Toast.LENGTH_LONG).show();
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}