Develop Reference

How to play sounds at accurate periods of time across different devices in Android

I'm developing a game in Android and I came across a very annoying, hard-to-find bug. The issue is that when you are using SoundPool to play your sounds, you can actually loop whatever sound you are playing. In this case, the issue is the "running steps" sound; this sound gets executed quite fast and continually (around every 400ms) when the main character is running.
Now when playing the sound on a regular (not so powerful) device e.g. Samsung SII, the sound is played every 500ms - however, if I run the very same code on another device (let's say, Samsung SIV, Samsung SIII), the sound plays twice or even three times faster.
It seems like the more powerful the device hardware specs are, the faster it plays. On some devices, it plays so fast that you almost hear one solid continuous sound. I've been looking for techniques to set a specific ratio on the time period between sound plays, but it doesn't work properly and the issue remains. Does anyone know how to fix it, either using SoundPool, MediaPlayer, or any other sound-controlling API on Android?

You could use an AudioTrack to play a continuous stream of PCM data, since you would pass a stream you could be sure about the interval between sounds. the downside could be a little delay when first starting the sound but it depends on the minimum buffer size, and it depends, I think, on android version and device. On my galaxy s2 android 4.1 it was about 20ms.if you think this could be an option I can post some code

The problem with just looping or using a regular interval for something like footsteps is that you have a possible decoupling of sound and visuals. If your sound gets delays or sped up, or your visuals get delayed or sped up, you would have to adjust for that delay dynamically and automatically. You already have that issue right here
A better solution would be to place a trigger on the exact event which should trigger the sound (in this case, the foot being placed down), which then plays the sound. This also means that if you have multiple sources of the sound (like multiple footsteps), you don't have to manually start the sound with the right interval.

I can't seem to replicate the issue on Galaxy Nexus and Nexus S, does that mean I fixed it? Or maybe you could show what you're doing differently from this:
SoundPool soundPool = new SoundPool(4, AudioManager.STREAM_MUSIC, 100);
Integer sound1 = soundPool.load(this, R.raw.file1, 1);
Integer sound2 = soundPool.load(this, R.raw.file2, 1);
playSound(sound1);
public void playSound(int sound) {
AudioManager mgr = (AudioManager)getSystemService(Context.AUDIO_SERVICE);
float volume = mgr.getStreamVolume(AudioManager.STREAM_MUSIC)
/ mgr.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
soundPool.play(sound, volume, volume, 1, -1, 1.0f);
}

If the problem is that you want to control the interval between the discrete sounds, The easiest way to do this is with a handler.
Basically you start a sound playing which is an asynchronous process. Then you use a handler to schedule a message to play the next sound sometime in the future. It will take some trial and error to get it right, but you will be guaranteed that the sound will start at the same interval after the previous sound on every device.
Here is some code to illustrate what I am talking about.
Here is a handler implementation you could use:
handler = new Handler() {
/* (non-Javadoc)
* #see android.os.Handler#handleMessage(android.os.Message)
*/
#Override
public void handleMessage(Message msg) {
if (msg.what == NEXT_ITEM_MSG) {
playNextSound();
}
else if (msg.what == SEQUENCE_COMPLETE_MSG) {
// notify a listener
listener.onSoundComplete()
}
}
};
Then you could write playNextSound like this:
private void playNextSound() {
if (mRunning) {
// Get the first item
SoundSequenceItem item = currentSequence.getNextSequenceItem();
if (item == null) {
Message msg = handler.obtainMessage(SEQUENCE_COMPLETE_MSG);
handler.sendMessage(msg);
return;
}
// Play the sound
int iSoundResId = item.getSoundResId();
if (iSoundResId != -1) {
player.playSoundNow(soundResId);
}
// schedule a message to advance to next item after duration
Message msg = handler.obtainMessage(NEXT_ITEM_MSG);
handler.sendMessageDelayed(msg, item.getDuration());
}
}
and your SoundSequenceItem could just be a simple class that has a sound file resource id and a duration. If you want to keep playing the sound while the character is moving you could do something like this:
public void onSoundComplete() {
if (character.isRunning()) {
currentSequence.addSequenceItem(new SoundSequenceItem(R.id.footsteps,500);
playNextSound();
}
}
Or you could modify playNextSound to continually play the same sound. Mine is written this way to be able to play different sounds in sequence.

I have had a lot of problems developing apps which used sounds and stuff like that. I would not suggest you to use SoundPool since it is bug-affected, and also be aware that looping sounds with SoundPool won't work on devices which are 4.3 and higher, see this open issue, at AOSP - Issue tracker.
I think that the solution is to go native and use OpenSL ES o similar libraries.

Detecting buffering error (or timeout) Android MediaPlayer - Use a Timer for timeout?

Apparently no exception is thrown so that I can recognize an error while buffering streaming audio content. For example I've disconnected my router and the app will continue to try to buffer the whole time. When I reconnect then it completes buffering and continues even after being disconnected for over a minute!
So the problem is I can't let my user sit there for that long without considering that a problem. What is the proper method to detect a buffering problem with the Android media player?
I'm thinking about using a Timer for a timeout. I'll start probably with 15 seconds (using a proxy I tested a 5kbps connection, which would be a worst case, was able to start playing in 6-10 seconds, so I think 15 seconds would be a reasonable timeout period). Does this sound like a good plan? If so should I create a new Timer with each buffer attempt or should I keep the same Timer throughout the lifetime of the playback service?
So basically I'm asking two questions:
1) What's the proper way to detect if a buffer is having a problem? Is there a listener I'm overlooking? I've tried MediaPlayer.OnErrorListener of course that doesn't fire in my tests. My conclusion is I have to have a timeout to detect a buffering error.
2) If I'm correct on number one, what is the proper way to use a Timer? Create one with each buffer attempt or reuse the same one? EDIT Also should I restart the (or cancel and create a new) Timer onBufferUpdate? With the onBufferUpdate listener I should know that some data is coming back so should maybe reset the timer with that.

From your question, I understand that the primary objective is to detect a situation if your player is stalled due to buffering and take some actions thereof. To handle this situation, I feel that the following 2 listeners may be helpful to identify the same.
MediaPlayer.onBufferingUpdate would provide the timely progress of the buffering. So, if there are 2 callbacks with same percent value, this could be an indication of potential buffering.
There is another listener MediaPlayer.onInfoListener which has some specific events which could be of interest to you. On this listener, if the what is MEDIA_INFO_BUFFERING_START, this would indicate that the player is pausing the playback for buffering i.e. trigger for your logic. Similarly MEDIA_INFO_BUFFERING_END indicates the restart of the playback after filling the buffers.

You Should see this article. The mediaplayer has a ErrorListener to get any error.
http://developer.android.com/reference/android/media/MediaPlayer.OnErrorListener.html

int count=40;//for 40 seconds to wait for buffering after it will finish the activity
//boolean timeoutflag=false;
timeout = new Handler(Looper.getMainLooper()) {
#Override
public void handleMessage(Message msg) {
System.out.println("value of count="+msg.getData().getLong("count"));
if (msg.getData().getBoolean("valid")) {
if (msg.getData().getLong("count") == 0 && !timeoutflag)
{
if (pDialog != null && pDialog.isShowing())
{
try
{
pDialog.dismiss();
}catch(Exception e)
{
e.printStackTrace();
}
}
Toast.makeText(getApplicationContext(),
"Unable To Load This Video", Toast.LENGTH_LONG).show();
finish();
} else {
}
}
}
};
timeout.postDelayed(null, 0);
new Thread(new Runnable() {
#Override
public void run() {
while (count > 0) {
try {
Thread.sleep(1020);
} catch (Exception e) {
}
Message msg = new Message();
Bundle b = new Bundle();
b.putBoolean("valid", true);
b.putLong("count", --count);
msg.setData(b);
timeout.sendMessage(msg);
}
}
}).start();
// set timeoutflag=true; in setOnPreparedListener of video view

For buffering during preparation, you have to set your own timer which calls player.reset() after some interval. This puts the player back into init state.
For buffering after preparation (during play) you have to monitor getPosition(). If it falls behind some maximum, call reset(). This allows you to set an experience threshold for your playback. Handles not only failed connection, but also choppy connection.
Best solution is to not use MediaPlayer. Use a public VLC derivative instead. MP has too many internalized private design limitations requiring horrible workarounds (eg. CANT add codecs). RTFM gives you false hope in this case.
Unless you are doing a very straight laced android app, don't depend on any android api. Some opensource substitutes are better supported, and for good reason.
(really bandeely olly jolly satisfying editorial rant deleted)

Media Player crash after use

I am working on a small application that plays back eight different .5 second midi files. I have an ontouch action that gets called everytime a specified object gets touched and within that I have an if/else if statement that plays the specified midi file depending on the object touched. When I run this, It works fine for the first several touches but after a while the playback stops, and then the app eventually crashes. What is going wrong here?
Basic Structure:
public ontouch(){
if (something >= 3){
mediaplayer s = mediaplayer.create(somethingmidi2);
s.start();
}else if (something < 3){
mediaplayer s = mediaplayer.create(somethingmidi);
s.start();
}
} `

Just a guess, but you probably aren't calling the release() method of the media player, nor reset() when you are reinitializing it.

How to shut off the sound MediaRecorder plays when the state changes

My Android application uses MediaRecorder on a SurfaceHolder to show a live preview of what the camera is capturing. Every time the user presses the REC button on the app, the app starts to record.
Every time the state of the MediaRecorder switches to/from 'start', Android automatically (?) fires off a beep. This beep sounds different from phone to phone, which makes me think that this beep is natively attached to the state change of MediaRecorder.
The beep is not played if the volume of the phone is set to silent.
I google it and did some research but I couldn't find a way to turn this beep off. Is it possible? If so, how?
The app was tested on: Nexus One 2.3.4, Desire HD 2.3.3

Ok the accepted answer did not work for me. On a Galaxy Nexus Running 4.2.1 (Jelly Bean) when recording via MediaRecorder I needed to use AudioManager.STREAM_RING because AudiManager.STREAM_SYSTEM did not work. It would always play a "chime" sound at beginning of each recording.
Here is my solution using "STREAM_RING" and others.
// disable sound when recording.
((AudioManager)activity.getApplicationContext().getSystemService(Context.AUDIO_SERVICE)).setStreamMute(AudioManager.STREAM_ALARM,true);
((AudioManager)activity.getApplicationContext().getSystemService(Context.AUDIO_SERVICE)).setStreamMute(AudioManager.STREAM_DTMF,true);
((AudioManager)activity.getApplicationContext().getSystemService(Context.AUDIO_SERVICE)).setStreamMute(AudioManager.STREAM_MUSIC,true);
((AudioManager)activity.getApplicationContext().getSystemService(Context.AUDIO_SERVICE)).setStreamMute(AudioManager.STREAM_RING,true);
((AudioManager)activity.getApplicationContext().getSystemService(Context.AUDIO_SERVICE)).setStreamMute(AudioManager.STREAM_SYSTEM,true);
((AudioManager)activity.getApplicationContext().getSystemService(Context.AUDIO_SERVICE)).setStreamMute(AudioManager.STREAM_VOICE_CALL,true);
// re-enable sound after recording.
((AudioManager)activity.getApplicationContext().getSystemService(Context.AUDIO_SERVICE)).setStreamMute(AudioManager.STREAM_ALARM,false);
((AudioManager)activity.getApplicationContext().getSystemService(Context.AUDIO_SERVICE)).setStreamMute(AudioManager.STREAM_DTMF,false);
((AudioManager)activity.getApplicationContext().getSystemService(Context.AUDIO_SERVICE)).setStreamMute(AudioManager.STREAM_MUSIC,false);
((AudioManager)activity.getApplicationContext().getSystemService(Context.AUDIO_SERVICE)).setStreamMute(AudioManager.STREAM_RING,false);
((AudioManager)activity.getApplicationContext().getSystemService(Context.AUDIO_SERVICE)).setStreamMute(AudioManager.STREAM_SYSTEM,false);
((AudioManager)activity.getApplicationContext().getSystemService(Context.AUDIO_SERVICE)).setStreamMute(AudioManager.STREAM_VOICE_CALL,false);
Also as the documentation states be sure to re-enable audio in the onPause() method.
I hope this helps someone tearing their hair out over this problem. This disables all sound streams. You can go through and work out which ones you specifically need. I found that different versions of android use different streams for the chime when mediarecorder runs. ie, STREAM_RING works for android 4.2.1 but for ICS it doesn't work.
Edit: As my comment below mentions, I can't get the sound disabled for Android OS 2.3.3 on a Samsung Galaxy S1. Anyone have luck with this?
Darrenp's solution helps to tidy up code but in a recent update to my phone (galaxy nexus android 4.3) the volume / recording beep started up again! The solution by user1944526 definitely helps. In an effort to make it easier to understand...
Use something like ,
// class variables.
Integer oldStreamVolume;
AudioManager audioMgr;
enableSound() {
setMuteAll(false);
if (audioMgr != null && oldStreamVolume != null) {
audioMgr.setStreamVolume(AudioManager.STREAM_RING, oldStreamVolume, 0);
}
}
disableSound() {
audioMgr = (AudioManager)activity.getApplicationContext().getSystemService(Context.AUDIO_SERVICE);
oldStreamVolume = audioMgr.getStreamVolume(AudioManager.STREAM_RING);
audioMgr.setStreamVolume(AudioManager.STREAM_RING, 0, 0);
}
For completeness each of those functions you could also call either darrenp's solution in a function or include all of the above STREAM_ lines. but for me now, these combined are working. Hope this helps someone...

try
((AudioManager)context.getSystemService(Context.AUDIO_SERVICE)).setStreamMute(AudioManager.STREAM_SYSTEM,true);
That mute all sounds.

Following on from #wired00's answer, the code can be simplified as follows:
private void setMuteAll(boolean mute) {
AudioManager manager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
int[] streams = new int[] { AudioManager.STREAM_ALARM,
AudioManager.STREAM_DTMF, AudioManager.STREAM_MUSIC,
AudioManager.STREAM_RING, AudioManager.STREAM_SYSTEM,
AudioManager.STREAM_VOICE_CALL };
for (int stream : streams)
manager.setStreamMute(stream, mute);
}
This works fine for now but if more streams are introduced in the future, this method may need updating. A more robust approach (though perhaps overkill) is to use reflection to get all the STREAM_* static fields:
List<Integer> streams = new ArrayList<Integer>();
Field[] fields = AudioManager.class.getFields();
for (Field field : fields) {
if (field.getName().startsWith("STREAM_")
&& Modifier.isStatic(field.getModifiers())
&& field.getType() == int.class) {
try {
Integer stream = (Integer) field.get(null);
streams.add(stream);
} catch (IllegalArgumentException e) {
// do nothing
} catch (IllegalAccessException e) {
// do nothing
}
}
}
Interestingly, there seem to be some streams that are not documented, namely STREAM_BLUETOOTH_SCO, STREAM_SYSTEM_ENFORCED and STREAM_TTS. I'm guessing/hoping there's no harm in muting these too!

I just had this problem on a Lenovo K900 running Android 4.2.1.
setStreamMute doesn't seem to do anything for me, but setStreamVolume works...
AudioManager audioMgr = (AudioManager)getSystemService(Context.AUDIO_SERVICE);
int oldStreamVolume = audioMgr.getStreamVolume(AudioManager.STREAM_RING);
audioMgr.setStreamVolume(AudioManager.STREAM_RING, 0, 0);
... do recording ...
audioMgr.setStreamVolume(AudioManager.STREAM_RING, oldStreamVolume, 0);

Add this code before the start:
AudioManager audioManager = (AudioManager) getApplicationContext().getSystemService(Context.AUDIO_SERVICE);
audioManager.setStreamMute(AudioManager.STREAM_SYSTEM, true);
audioManager.setStreamMute(AudioManager.STREAM_MUSIC,true);
And add this code after the stop:
AudioManager audioManager = (AudioManager) getApplicationContext().getSystemService(Context.AUDIO_SERVICE);
audioManager.setStreamMute(AudioManager.STREAM_SYSTEM, false);
audioManager.setStreamMute(AudioManager.STREAM_MUSIC,false);
There are countries/firmwares that use STREAM_SYSTEM and others using STREAM_MUSIC. There are also countries where this is illegal but use a different channel.

Android SoundPool sometimes plays sound twice when loop param is set to 0

Here is what I'm doing:
private SoundPool pool;
private int soundId;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
// new SoundPool with three channels, STREAM_MUSIC, default quality
pool = new SoundPool(3, AudioManager.STREAM_MUSIC, 0);
// load sound with current context, click resource, priority 1
soundId = pool.load(this, R.raw.click, 1);
// originally I wasn't using this but it seemed to help a bit
// set no loop for soundId
pool.setLoop(soundId, 0);
}
private void play()
{
Log.v(TAG, "Play the sound once!");
// half volume L & R, priority 1, loop 0, rate 1
pool.play(soundId, 0.5f, 0.5f, 1, 0, 1);
}
#Override
public void onDestroy()
{
super.onDestroy();
// release the pool
pool.release();
}
Originally I was using a .wav file for the click sound and the problem would occur 90% of the time. I added setLoop and it appears to reduce it a tiny bit.
I thought it might be a problem with loading .wav files so I converted the file to .mp3. Now the problem happens 5% of the time, but it still happens. I built with and without the setLoop call and it appears that including it helps a tiny bit.
As you can see I have added a debug log message to ensure that I am not accidentally calling the play function twice. According to the log output, the sound is only played once but I hear the sound twice.
I have also used several different sound files. Some of the files seem to repeat more frequently than others. I don't see any correlations except it happens more frequently with .wav files.
I see the problem happening on Samsung Continuum running 2.1 (min & target API: level 7). I haven't experienced any extra looping with any market apps I've downloaded on the same device. Unfortunately, I don't have other devices to test with.
I have only found one other person experiencing this issue and he or she was also using a Samsung device.
Here is a link to the other issue reported:
https://stackoverflow.com/q/4873995/695336
At this point I guess I'll try making a release build to see if it still happens and then maybe convert to .ogg format. After that I'll probably try switching to MediaPlayer to see if I get the same results.
Thanks for your help.