Develop Reference

How can I stop media player when other media player app starts?

I want to stop media player when some other media player applications start.
I don't know how to do this.

You'll need to add listener for AudioFocusChange.
Refer: https://developer.android.com/reference/android/media/AudioManager.OnAudioFocusChangeListener.html

I've done the similar thing in a project where when my app starts playing, Google Play Music pause and vice versa.
AudioManager am = null;
// Request focus for music stream and pass AudioManager.OnAudioFocusChangeListener
// implementation reference
int result = am.requestAudioFocus(this, AudioManager.STREAM_MUSIC,
AudioManager.AUDIOFOCUS_GAIN);
if(result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED)
{
// Play
}
// Implements AudioManager.OnAudioFocusChangeListener
#Override
public void onAudioFocusChange(int focusChange)
{
if(focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT)
{
// Pause
}
else if(focusChange == AudioManager.AUDIOFOCUS_GAIN)
{
// Resume
}
else if(focusChange == AudioManager.AUDIOFOCUS_LOSS)
{
// Stop or pause depending on your need
}
}

Android stop sounds

I am writing an alert app. When an alert is received, I want to stop all current sounds (like music) and play my alert sound. After the user has done something and the activity will be closed, the previous sounds should continue.
Thats the same like someone calls you. How can I achieve this behaviour?

You can request audio focus. Once you are done with your own audio, abandon audio focus so other apps can start playing sound again. You will be notified of other apps requesting audio focus too, thus being able to pause and resume your own sounds.
Requesting audio focus:
AudioManager am = mContext.getSystemService(Context.AUDIO_SERVICE);
// Request audio focus for playback
int result = am.requestAudioFocus(afChangeListener,
// Use the music stream.
AudioManager.STREAM_MUSIC,
// Request permanent focus.
AudioManager.AUDIOFOCUS_GAIN);
if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
am.registerMediaButtonEventReceiver(RemoteControlReceiver);
// Start playback.
}

With the help of Julius Skripkauskas' answer I use the following code:
to start the alert sound:
private void playSound(){
try{
Log.d(TAG, "request audio focus");
this.am=(AudioManager)getSystemService(Context.AUDIO_SERVICE);
int result=this.am.requestAudioFocus(afListener, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN_TRANSIENT_EXCLUSIVE);
if(result==AudioManager.AUDIOFOCUS_REQUEST_GRANTED){
Log.d(TAG, "audio focus granted");
this.player=new MediaPlayer();
this.player.setOnPreparedListener(new OnPreparedListener(){
#Override
public void onPrepared(MediaPlayer mp) {
mp.start();
}});
this.player.setOnCompletionListener(new OnCompletionListener(){
#Override
public void onCompletion(MediaPlayer mp) {
am.abandonAudioFocus(afListener);
}});
this.player.setAudioStreamType(AudioManager.STREAM_MUSIC);
this.player.setDataSource(getApplicationContext(), Uri.parse("android.resource://" + getPackageName() + "/" + R.raw.sound ));
this.player.prepareAsync();
}
}catch(Exception e){
Log.e(TAG, "error playing music." + e.getMessage(), e);
}
}
The Listener:
I simply stop the sound because I will only play the sound once focus was granted. If the sound will get interrupted by an other app, it doesn't matter...
private AudioManager.OnAudioFocusChangeListener afListener = new AudioManager.OnAudioFocusChangeListener(){
#Override
public void onAudioFocusChange(int focusChange) {
Log.d(TAG, "audio focus changed" + Integer.toString(focusChange));
if(player==null){
// we don't play audio
return;
}
player.stop();
}};
It is important to consider to add the OnCompletionListener to the player where to call am.abandonAudioFocus(afListener) to release the audio focus immediately after the sound was played.

How to pause audioplayer when other app need audio

How to pause the audio player when I launch the radio app that I develop?
And "vice-versa" , How to pause my app when the user launch the audioplayer when my app is running in background.

You App needs to request the Audio-Focus, more about that here. Once you no longer need it you can abandon the focus, which returns it to the Application which had it previously to yours.

Use OnAudioFocusChangeListener to detect if there are other apps requesting audio focus; if so, pause your audio player.
am = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
afChangeListener = new OnAudioFocusChangeListener() {
public void onAudioFocusChange(int focusChange) {
if (focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT){
// Pause playback
} else if (focusChange == AudioManager.AUDIOFOCUS_GAIN) {
// Resume playback
} else if (focusChange == AudioManager.AUDIOFOCUS_LOSS) {
abandonAudioFocus();
}
}
};
Similar SO question is here

Stopping my audio when other audio has started playing on the device

I am playing an audio using MediaPlayer class. I have a requirement where audio played by my app should automatically stop when some other songs started playing on the device by the user. How to get notified that some other audio has started playing on the device in my app? Please advise.
UPDATED:
I tried this code, it works for the first time. I.e, when I launch my app and play an audio in my app, my app is playing an audio. Then, When I open some music player and play some other audio there, My app detects notification in "AUDIOFOCUS_LOSS". I am stopping my audio here. Then when again play audio in my app, and then coming back to music player and play some other audio there, this time my app doesn't get detected for this notification, so I couldn't do stop again my audio. This is my issue now.
Could someone help me to solve this please?
public class MyActivity extends ActionBarActivity implements OnCompletionListener, OnPreparedListener, OnErrorListener, OnBufferingUpdateListener, AudioManager.OnAudioFocusChangeListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_hclsquad_fm);
audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
audioManager.requestAudioFocus(this, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);
}
#Override
public void onAudioFocusChange(int focusChange) {
switch (focusChange) {
case AudioManager.AUDIOFOCUS_GAIN:
Toast.makeText(MyActivity.this, "Focus GAINED", Toast.LENGTH_LONG).show();
break;
case AudioManager.AUDIOFOCUS_LOSS:
case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT:
Toast.makeText(MyActivity.this, "Focus LOSS", Toast.LENGTH_LONG).show();
if(mediaPlayer != null)
killMediaPlayer();
break;
case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:
Toast.makeText(MyActivity.this, "Focus LOSS TRANSIENT", Toast.LENGTH_LONG).show();
break;
default:
}
}

Try this code below. I found this answer here
OnAudioFocusChangeListener listener = new OnAudioFocusChangeListener() {
public void onAudioFocusChange(int focusChange) {
if (focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK){
// Lower the volume
} else if (focusChange == AudioManager.AUDIOFOCUS_GAIN) {
// Raise it back to normal
}
}
};
AudioManager am = (AudioManager)getSystemService(Context.AUDIO_SERVICE);
int request = am.requestAudioFocus(listener,
AudioManager.STREAM_MUSIC,
AudioManager.AUDIOFOCUS_GAIN);

Responsible apps will always get audio focus before playing audio. I don't think it is possible for you to detect when another app plays audio if it does not request audio focus.
Instead of requesting audio focus in your onCreate, do it before you start to play audio:
private void play(){
requestAudioFocus();
}

You are loosing audio focus. You should call
requestAudioFocus();
to get control back.

Losing Audiofocus

i wrote a podcast audio player and included the audio focus principle.
This is my method, which is called in the onPrepared() method of the media player:
private boolean requestAudioFocus(){
AudioManager am = (AudioManager) getSystemService(AUDIO_SERVICE);
OnAudioFocusChangeListener afChangeListener = new OnAudioFocusChangeListener() {
public void onAudioFocusChange(int focusChange) {
if (focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT){
pause();
} else if (focusChange == AudioManager.AUDIOFOCUS_GAIN) {
play();
} else if (focusChange == AudioManager.AUDIOFOCUS_LOSS) {
Log.d("MYAUDIOSERVICE","Audio Focus lost");
finish();
}
}
};
// Request audio focus for playback
int result = am.requestAudioFocus(afChangeListener,
// Use the music stream.
AudioManager.STREAM_MUSIC,
// Request permanent focus.
AudioManager.AUDIOFOCUS_GAIN);
if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
return true;
}
else{
return false;
}
}
The problem is:
Everything works finde when starting the app and playing the first podcast. Audiofocus is gained and the podcast keeps playing.
When i stop playback and start another podcast the audiofocus is gained again, but shortly after AudioManager.AUDIOFOCUS_LOSS is receiver by the onAudioFocusChangeListener.
I guess thats the case because my app has the focus, request it again, gains it but at the same time loses the "old" one.
Am i right, and if if thats correct, can i just give up the audio focus when ending playback on the old podcast ?
Thx in advance