Develop Reference

Android : Record audio app crash

Everybody,
I'm trying to make a simple audio recording.
The audio is record perfectly when record button is clicked.
I try to record another audio and play it back. It crash when I try to play the 2nd audio.
Can you please help me on fixing this app so that I can record audio multiple time without crashing the app.
Here's the code.
stop.setEnabled(false);
play.setEnabled(false);
outputFile = Environment.getExternalStorageDirectory().getAbsolutePath() + "/recording.3gp";;
myAudioRecorder=new MediaRecorder();
myAudioRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
myAudioRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
myAudioRecorder.setAudioEncoder(MediaRecorder.OutputFormat.AMR_NB);
myAudioRecorder.setOutputFile(outputFile);
record.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
myAudioRecorder.prepare();
myAudioRecorder.start();
}
catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
record.setEnabled(false);
stop.setEnabled(true);
Toast.makeText(getApplicationContext(), "Recording started", Toast.LENGTH_LONG).show();
}
});
stop.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
myAudioRecorder.stop();
myAudioRecorder.reset();
record.setEnabled(true);
stop.setEnabled(false);
play.setEnabled(true);
Toast.makeText(getApplicationContext(), "Audio recorded successfully",Toast.LENGTH_LONG).show();
}
});
play.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) throws IllegalArgumentException,SecurityException,IllegalStateException {
MediaPlayer m = new MediaPlayer();
try {
m.setDataSource(outputFile);
}
catch (IOException e) {
e.printStackTrace();
}
try {
m.prepare();
}
catch (IOException e) {
e.printStackTrace();
}
m.start();
Toast.makeText(getApplicationContext(), "Playing audio", Toast.LENGTH_LONG).show();
}
});
Thanks!

You don't seem to enable record button when stop button is clicked. Write
record.setEnabled(true);
in the onClick() method implementation of stop button.
Another case is when stop button is clicked you are setting myAudioRecorder = null. If after this record button is clicked you will get a NullPointerException on this statement
myAudioRecorder.prepare() //exception
Solution will be to remove the statement of setting myAudioRecorder to null in onClick() implementation of stop.
Another problem comes because of this statement myAudioRecorder.release(). You can't get back the previous instance of MediaRecorder once you have released the resource. Either reinitialize myAudioRecorder each time you record or do not release the resource after stop has been clicked. To look at MediaRecorder lifecycle see this.
Here is a reference code you can look and understand. Please catch exceptions wherever required.
//package name
//imports
public class RecordPlayActivity extends AppCompatActivity implements View.OnClickListener {
// declare buttons here
private MediaRecorder myAudioRecorder;
private String recordOutputFile;
private MediaPlayer mediaPlayer;
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(null);
setContentView(R.layout.layout_name);
//find buttons view by Id here
record.setOnClickListener(this);
stop.setOnClickListener(this);
play.setOnClickListener(this);
recordOutputFile = Environment.getExternalStorageDirectory().getAbsolutePath() + "/recording.3gp";
myAudioRecorder = new MediaRecorder();
myAudioRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
myAudioRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
myAudioRecorder.setAudioEncoder(MediaRecorder.OutputFormat.AMR_NB);
myAudioRecorder.setOutputFile(recordOutputFile);
mediaPlayer = new MediaPlayer();
mediaPlayer.setDataSource(recordOutputFile);
//Initial condition
//stop.setEnabled(false); //not required as stop can be made always enabled
play.setEnabled(false);
}
#Override
public void onClick(View view){
switch(view.getId()){
case R.id.idForRecord:
myAudioRecorder.prepare();
myAudioRecorder.start();
//Recording started
record.setEnabled(false);
// don't make play enabled cause you dont want to play
// and record at same time without stopping record.
play.setEnabled(false); //required because play can get enabled from stop but it should not remain when recording
break;
case R.id.idForStop:
//if clicked after record
myAudioRecorder.stop();
myAudioRecorder.reset();
//if clicked after play
if(mediaPlayer.isLooping()) {
mediaPlayer.stop();
}
//recording stopped and saved;
record.setEnabled(true);
play.setEnabled(true);
break;
case R.id.idForPlay:
mediaPlayer.prepare();
mediaPlayer.start();
//playing
record.setEnabled(false); // you dont wanna play and record at same time
break;
default:
}
}
}`
Hope these all solves your problem.

It's crashing because outputFile = Environment.getExternalStorageDirectory().getAbsolutePath() + "/recording.3gp" ; directs to top directory od Android OS ...
If you use this path Environment.getExternalStorageDirectory()+File.separator+"sounds" "/recording.3gp" then your recording will be going into one level down directory "sounds" into directory sounds .
App will not crash if you recording is in folder down from top level path ...

Android camera fails taking a picture every second

Let me start by saying that if image shooting interval is anything more than 1 second it works. For example taking a picture every 2 seconds works perfectly fine. But taking a picture every second sometimes throws java.lang.RuntimeException: takePicture failed. What could be causing this kind of a behaviour?
Here is the code I use and it is in Service:
#Override
public void onCreate()
{
super.onCreate();
prefs = getSharedPreferences("general",Context.MODE_PRIVATE);
handler = new Handler();
shotInterval = prefs.getInt(getString(R.string.prefs_int_imageShootingFrequency),1);
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
Toast.makeText(this, "No camera on this device", Toast.LENGTH_LONG).show();
} else {
cameraId = findBackFacingCamera();
if (cameraId < 0) {
Toast.makeText(this, "No front facing camera found.",Toast.LENGTH_LONG).show();
} else {
camera = Camera.open(cameraId);
}
}
cameraParameters = camera.getParameters();
cameraParameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE); //set camera to continuously auto-focus
camera.setParameters(cameraParameters);
pictureTaker.run(); // Start looping
}
Runnable pictureTaker = new Runnable() {
#Override
public void run() {
try {
takePicture();
} finally {
// 100% guarantee that this always happens, even if
// your update method throws an exception
handler.postDelayed(pictureTaker, shotInterval*1000);
}
}
};
private void takePicture(){
SurfaceView view = new SurfaceView(this);
try {
camera.setPreviewDisplay(view.getHolder());
camera.startPreview();
camera.takePicture(null, null,new PhotoHandler(getApplicationContext()));
} catch (IOException e) {
e.printStackTrace();
}
}

You should launch postDelayed() from the onPictureTaken() callback. You can check the system timer on call to takePicture() and reduce the delay respectively, to keep 1000ms repetition, but maybe once in a while, this delay will reach 0.

How to manage Android MediaPlayer state, errors, and exceptions?

I am trying to play a short sound byte after processing a scanned bar code. My code currently works fine for as many as twenty scans. However, eventually the MediaPlayer throws the following error repeatedly even after the app has been killed:
MediaPlayer: Error (-38, 0)
MediaPlayer: Attempt to perform seekTo in wrong state: mPlayer=0xXXXXXX, mCurrentState=0
--the X's representing a random 6 digit memory address--
I originally was playing the sound byte off of the UI thread. Since I've created a handler in an attempt to mitigate the issue. This is how I access the handler:
try {
mHandler.post(mScanFeedback);
} catch (IllegalStateException e) {
System.out.println("Media player state error");
e.printStackTrace();
}
Here is the code for the handler:
private Runnable mScanFeedback = new Runnable(){
public void run() {
if(getString(R.string.working).equals(mStatusHourly)) {
final MediaPlayer mediaPlayer = MediaPlayer.create(getBaseContext(), R.raw.bleep_working);
mediaPlayer.setOnErrorListener(new OnErrorListener() {
public boolean onError(MediaPlayer mp, int what, int extra) {
mediaPlayer.reset();
System.out.println("Media Player onError callback!");
return true;
}
});
mediaPlayer.start();
try {
Thread.sleep(150);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
mediaPlayer.release();
}
} else if(getString(R.string.not_working).equals(mStatusHourly)) {
final MediaPlayer mediaPlayer = MediaPlayer.create(getBaseContext(), R.raw.bleep_not_working);
mediaPlayer.setOnErrorListener(new OnErrorListener() {
public boolean onError(MediaPlayer mp, int what, int extra) {
mediaPlayer.reset();
System.out.println("Media Player onError callback!");
return true;
}
});
mediaPlayer.start();
try {
Thread.sleep(275);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
mediaPlayer.release();
}
} else {
System.out.println("Audio feedback failed as status was indeterminate.");
}
}
};
In the beginning I didn't call release() and adding it hasn't seemed to make it work any better or worse. The onError callback is never called when the problem occurs. I've tried to reset() the media player after each time it is played but that throws an error. Right now I resort to restarting the phone to keep my Logcat from being unusable by the onslaught of the same two error lines repeated continually.
I'm using zxing's bar code scanner and there is a short beep played within that activity as confirmation that the bar code has been captured. A small part of me wonders if their isn't a conflict there.
I'm still new to programming and this is my first question on stack overflow. Let me know if I should have provided any additional information or if I should try to keep it a little more lean.
Update:
I was unable to resolve the issue with the MediaPlayer. However, I was able to work around the issue by switching to a SoundPool implementation. The class below provides the needed functionality.
import java.util.HashMap;
import android.content.Context;
import android.media.AudioManager;
import android.media.SoundPool;
public class SoundManager {
private SoundPool mSoundPool;
private HashMap mSoundPoolMap;
private AudioManager mAudioManager;
private Context mContext;
public void initSounds(Context theContext) {
mContext = theContext;
mSoundPool = new SoundPool(4, AudioManager.STREAM_MUSIC, 0);
mSoundPoolMap = new HashMap();
mAudioManager = (AudioManager)mContext.getSystemService(Context.AUDIO_SERVICE);
}
public void addSound(int index, int SoundID) {
mSoundPoolMap.put(index, mSoundPool.load(mContext, SoundID, 1));
}
public void playSound(int index) {
float streamVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
streamVolume = streamVolume / mAudioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
mSoundPool.play(index, streamVolume, streamVolume, 1, 0, 1f);
}
public void playLoopedSound(int index) {
float streamVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
streamVolume = streamVolume / mAudioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
mSoundPool.play(index, streamVolume, streamVolume, 1, -1, 1f);
}
}
Which I then accessed from my Activity with:
mSoundManager = new SoundManager();
mSoundManager.initSounds(getBaseContext());
mSoundManager.addSound(1, R.raw.bleep_working);
mSoundManager.addSound(2, R.raw.bleep_not_working);
mSoundManager.playSound(1);
mSoundManager.playSound(2);

Trouble with Android Camera

I have some code I have been experimenting with to see what I can do with the camera device. This following code works, but I have some issues with it that I cannot seem to solve.
The first call never works. The first time running the code the onPictureTaken callback is never called, so the file is never written. However the camera goes through all the other steps, including making the fake shutter noise.
I can't seem to set the picture size to something other than whatever it defaults to. If I try to set it to something else, the code stops working. Does the same as above, where the camera goes through all the motions, but the onPictureTaken callback is never called.
When the pictures are saved to the DCIM folder, the taken pictures do not show up in the default 'Photos' app on my phone, unless i reboot the phone.
Is there any way through code to disable the shutter noise?
Sorry, the code is a little messy because its an experiment.
Also, this code is executed in a BroadcastReceiver
#Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
if(intent.getAction().equals(TAKE_PICTURE_INTENT))
{
Toast.makeText(context, "Test", Toast.LENGTH_LONG).show();
System.out.println("GOT THE INTENT");
try
{
Camera camera = Camera.open();
System.out.println("CAMERA OPENED");
Parameters params = camera.getParameters();
params.set("flash-mode", "off");
params.set("focus-mode", "infinity");
params.set("jpeg-quality", "100");
//params.setPictureSize(2592, 1952);
String str = params.get("picture-size" + "-values");
System.out.println(str);
String size = str.split(",")[0];
System.out.println(size);
//params.set("picture-size", size);
camera.setParameters(params);
System.out.println("CAMERA PARAMETERS SET");
camera.startPreview();
System.out.println("CAMERA PREVIEW STARTED");
camera.autoFocus(new AutoFocusCallBackImpl());
}
catch(Exception ex)
{
System.out.println("CAMERA FAIL, SKIP");
return ;
}
}//if
}//onreceive
private void TakePicture(Camera camera)
{
camera.takePicture(new Camera.ShutterCallback() {
#Override
public void onShutter() {
// TODO Auto-generated method stub
System.out.println("CAMERA SHUTTER CALLBACK");
}
}
, null,
new Camera.PictureCallback() {
public void onPictureTaken(byte[] imageData, Camera c) {
//c.release();
System.out.println("CAMERA CALLBACK");
FileOutputStream outStream = null;
try {
System.out.println("Start Callback");
File esd = Environment.getExternalStorageDirectory();
outStream = new FileOutputStream(esd.getAbsolutePath() + String.format(
"/DCIM/%d.jpg", System.currentTimeMillis()));
outStream.write(imageData);
outStream.close();
System.out.println( "onPictureTaken - wrote bytes: " + imageData.length);
} catch (FileNotFoundException e) {
e.printStackTrace();
System.out.println("File not found exception");
} catch (IOException e) {
e.printStackTrace();
System.out.println("IO exception");
} finally {
System.out.println("Finally");
c.release();
}
}
}
);
//camera.release();
}//TAKE PICTURE
private class AutoFocusCallBackImpl implements Camera.AutoFocusCallback {
#Override
public void onAutoFocus(boolean success, Camera camera) {
//bIsAutoFocused = success; //update the flag used in onKeyDown()
System.out.println("Inside autofocus callback. autofocused="+success);
//play the autofocus sound
//MediaPlayer.create(CameraActivity.this, R.raw.auto_focus).start();
if(success)
{
System.out.println("AUTO FOCUS SUCCEDED");
}
else
{
System.out.println("AUTO FOCUS FAILED");
}
TakePicture(camera);
System.out.println("CALLED TAKE PICTURE");
}
}//AUTOFOCUSCALLBACK

1.First of all put all camera logic out of BroadCast receiver & put it into seprate Activity.
2.
When the pictures are saved to the DCIM folder, the taken pictures do not show up in the default 'Photos' app on my phone, unless i reboot the phone.
because MediaScanner needs to be called to rescan images/changes once you take photo. When u reboot phone mediascanner scans media & finds new images. for this isuue you should check out MediaScanner.
3.Follow Android Camera Tutorial & Camera API
-Thanks

Android media player stop playing while in background

I'm making music player app with simple functionality. But when I listen music on my phone with Android 6, sometimes music stops playing until I turn on display again with power button. Then next song is playing, so it seems like it's problem with loading next song. I tried to write new app just to test it out, for this purpose I used this tutorial:
https://code.tutsplus.com/tutorials/background-audio-in-android-with-mediasessioncompat--cms-27030
To this example I added ArrayList with paths to songs. In mediaPlayer onCompletionListener I increase track counter and load new song to media player.
My code:
private void initMediaPlayer() {
mMediaPlayer = new MediaPlayer();
mMediaPlayer.setWakeMode(getApplicationContext(), PowerManager.PARTIAL_WAKE_LOCK);
mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mMediaPlayer.setVolume(1.0f, 1.0f);
mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
#Override
public void onCompletion(MediaPlayer mediaPlayer)
{
onTrackCompletion();
}
});
private void onTrackCompletion()
{
NextTrack();
Play();
}
private void NextTrack()
{
playlistPosition++;
if (playlistPosition == playlists.get(playlistCurrent).size){
playlistPosition = 0;
}
sendAction(ACTION_TRACK_NEXT);
if(mMediaPlayer.isPlaying()){
Pause();
}
loadSong();
Play();
}
private void loadSong()
{
String path = playlists.get(playlistCurrent).getPath(playlistPosition);
if(path == null || path == "")
{
return;
}
try
{
try
{
mMediaPlayer.setDataSource(path);
} catch( IllegalStateException e ) {
mMediaPlayer.release();
initMediaPlayer();
mMediaPlayer.setDataSource(path);
}
initMediaSessionMetadata();
} catch (IOException e) {
return;
}
try {
mMediaPlayer.prepare();
} catch (IOException e) {}
sendTrackData();
}
I don't know anymore why this doesn't work. In manifest I have WAKE_LOCK permission. I also set wake lock for Media player.
Edit:
Today I tried to move loading song into onPlayFromMediaId. I made broadcast from AutoActivity where is Media player to Main Activity and send back onPlayFromMediaId with path to song. But seems like this doesn't work either.I also find out that changing volume with buttons also wake up app.
Edit2:
I made many tests and added debug string in many places in code. And I found out that app stops at mediaplayer.prepare() until I trigger any action on phone (turn on display, volume up/down, click headset button). But I don't know how to fix this bug. I tried to use prepareAsync, but didn't help.

Unless you use foreground service, the system will kill your process and mediaplayer will stop.
below is a part from from a foreground service ( notification example).
builder.setContentTitle(aMessage) // required
.setSmallIcon(R.mipmap.ic_launcher)
.setContentText(this.getString(R.string.app_name)) // required
.setAutoCancel(false)
.setContentIntent(pendingIntent)
.setVibrate(new long[]{0L})
.setPriority(Notification.PRIORITY_HIGH);
int mId = 1489;
startForeground(mId, builder.build());
The above code is tested and working fine.