Develop Reference

how can i set mediaPlayer speed for api less then 23

player.setPlaybackParams(player.getPlaybackParams().setSpeed(0.5f));
this requires an api call 23
iam trying to use SoundPool but it is not so efficent as of MediaPlayer Is any alternate to SoundPool for audioPlaying
final float playbackSpeed=1.5f;
final SoundPool soundPool = new SoundPool(4, AudioManager.STREAM_MUSIC, 100);
final String path=Environment.getExternalStorageDirectory().getAbsolutePath() + "/folioreader/audio"+".mp3";
final int soundId = soundPool.load(path, 1);
AudioManager mgr = (AudioManager) mHalfSpeed.getContext().getSystemService(Context.AUDIO_SERVICE);
final float volume = mgr.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
soundPool.setOnLoadCompleteListener(new SoundPool.OnLoadCompleteListener()
{
#Override
public void onLoadComplete(SoundPool arg0, int arg1, int arg2)
{
soundPool.play(soundId, volume, volume, 1, 0, playbackSpeed);
}
});
soundPool.pause(soundId)

Use media codec class. This class can decode it and you can use Audio Track on decoded data to render (play) it. But you need to skip the samples as per your speed requirement to play in the particular speed. This approach should work. Refer mediacodec and audiotrack in android developer resources.

Android: Using the accelerometer to create a simple maraca app

I'm trying to learn how to use the accelerometer by creating (what I thought would be) a simple app to mimic a crude maraca.
The objective is that when the phone is flicked downwards quickly, it emits a maraca sound at the end of that flick, and likewise a different sound is emitted at the end of an upward flick.
The strategy for implementing this is to detect when the acceleration passes over a certain threshold. When this happens, ShakeIsHappening is set to true, and the data from the z axis is fed into an array. A comparison is made to see whether the first position in the z array is greater or lesser than the most recent position, to see whether the phone has been moved upwards or downwards. This is stored in a boolean called zup.
Once the acceleration goes below zero, we assume the flick movement has ended and emit a sound, chosen depending on whether the movement was up or down (zup).
Here is the code:
public class MainActivity extends Activity implements SensorEventListener {
private float mAccelNoGrav;
private float mAccelWithGrav;
private float mLastAccelWithGrav;
ArrayList<Float> z = new ArrayList<Float>();
public static float finalZ;
public static boolean shakeIsHappening;
public static int beatnumber = 0;
public static float highZ;
public static float lowZ;
public static boolean flick;
public static boolean pull;
public static SensorManager sensorManager;
public static Sensor accelerometer;
private SoundPool soundpool;
private HashMap<Integer, Integer> soundsMap;
private boolean zup;
private boolean shakeHasHappened;
public static int shakesound1 = 1;
public static int shakesound2 = 2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
results = (TextView) findViewById(R.id.results);
clickresults = (TextView) findViewById(R.id.clickresults);
sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
accelerometer = sensorManager
.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
mAccelNoGrav = 0.00f;
mAccelWithGrav = SensorManager.GRAVITY_EARTH;
mLastAccelWithGrav = SensorManager.GRAVITY_EARTH;
soundpool = new SoundPool(4, AudioManager.STREAM_MUSIC, 100);
soundsMap = new HashMap<Integer, Integer>();
soundsMap.put(shakesound1, soundpool.load(this, R.raw.shake1, 1));
soundsMap.put(shakesound2, soundpool.load(this, R.raw.shake1, 1));
}
public void playSound(int sound, float fSpeed) {
AudioManager mgr = (AudioManager)getSystemService(Context.AUDIO_SERVICE);
float streamVolumeCurrent = mgr.getStreamVolume(AudioManager.STREAM_MUSIC);
float streamVolumeMax = mgr.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
float volume = streamVolumeCurrent / streamVolumeMax;
soundpool.play(soundsMap.get(sound), volume, volume, 1, 0, fSpeed);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
#Override
public void onSensorChanged(SensorEvent event) {
float x = event.values[0];
float y = event.values[1];
z.add((event.values[2])-SensorManager.GRAVITY_EARTH);
mLastAccelWithGrav = mAccelWithGrav;
mAccelWithGrav = android.util.FloatMath.sqrt(x * x + y * y + z.indexOf(z.size()-1) * z.indexOf(z.size()-1));
float delta = mAccelWithGrav - mLastAccelWithGrav;
mAccelNoGrav = mAccelNoGrav * 0.9f + delta; // Low-cut filter
if (mAccelNoGrav > 3) {
shakeIsHappening = true;
z.clear();
}
if (mAccelNoGrav < 0) {
if (shakeIsHappening) {
shakeIsHappening = false;
shakeHasHappened = true;
}
}
if (shakeIsHappening && z.size() != 0) {
if (z.get(z.size()-1) > z.get(0)) {
zup = true;
} else if (z.get(0) > z.get(z.size()-1)) {
zup = false;
}
}
if (shakeHasHappened) {
Log.d("click", "up is" + zup + "Low Z:" + z.get(0) + " high Z:" + z.get(z.size()-1));
if (!zup) {
shakeHasHappened = false;
playSound(shakesound2, 1.0f);
z.clear();
} else if (zup) {
shakeHasHappened = false;
playSound(shakesound1, 1.0f);
z.clear();
}
}
}
Some of the problems I'm having are:
I think ShakeHasHappened kicks in when deceleration starts, when acceleration goes below zero. Perhaps this should be when deceleration stops, when acceleration has gone negative and is now moving back towards zero. Does that sound sensible?
The way of detecting whether the motion is up or down isn't working - is this because I'm not getting an accurate reading of where the phone is when looking at the z axis because the acceleration is also included in the z-axis data and therefore isn't giving me an accurate position of the phone?
I'm getting lots of double clicks, and I can't quite work out why this is. Sometimes it doesn't click at all.
If anyone wants to have a play around with this code and see if they can find a way of making it more accurate and more efficient, please go ahead and share your findings. And if anyone can spot why it's not working the way I want it to, again please share your thoughts.
To link sounds to this code, drop your wav files into your res\raw folder and reference them in the R.raw.shake1 bit (no extension)
Thanks
EDIT: I've done a bit of research and have stumbled across something called Dynamic Time Warping. I don't know anything about this yet, but will start to look in to it. Does anyone know if DTW could be a different method of achieving a working maraca simulator app?

I can give you some pointers on this:
First of all, I noticed that you're using the same resource for both outcomes:
soundsMap.put(shakesound1, soundpool.load(this, R.raw.shake1, 1));
soundsMap.put(shakesound2, soundpool.load(this, R.raw.shake1, 1));
The resource in case of shakesound2 should be R.raw.shake2.
Second, the following only deals with one of the motions:
if (mAccelNoGrav > 3)
This should be changed to:
if (mAccelNoGrav > 3 || mAccelNoGrav < -3)
Currently, you are not intercepting downward motion.
Third, acceleration value of 3 is rather low. If you want to avoid/filter-out normal arm movement, this value should be around 6 or 7 and -6 or -7.
Fourth, you do not need to store z values to check whether the motion was up or down. You can check whether:
mAccelnoGrav > 6 ===> implies motion was upwards
mAccelnoGrav < -6 ===> implies motion was downwards
You can use this information to set zup accordingly.
Fifth: I can only guess that you are using if (mAccelNoGrav < 0) to play the sound when the motion ends. In that case, this check should be changed to:
if (mAccelNoGrav < epsilon || mAccelNoGrav > -epsilon)
where epsilon is some range such as (-1, 1).
Sixth, you should include a lockout period in your application. This would be the period after all conditions have been met and a sound is about to be played. For the next, say 1000 ms, don't process the sensor values. Let the motion stabilize. You'll need this to avoid getting multiple playbacks.
Note: Please include comments in your code. At the very least, place comments on every block of code to convey what you are trying to accomplish with it.

I tried to implement it by myself a time ago, and ended up using this solution.-
http://jarofgreen.co.uk/2013/02/android-shake-detection-library/
based on the same concept in your question.

Android play music in a random amount of time

Now I can play a music in android. But I want to play this sound in a random amount of time between 2 to 8 seconds.How Can I randomly play it that for example the first time, it plays for 2 seconds, the next time 7 sec and so on? Can anybody help me?

Go through these links:
Random number Generation
Media Player
Timer
you will get an idea.

Sound in android is played like this :
AudioManager audioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
int mSoundID = mSoundPool.load(this, R.raw.sound1, 1);
float lActualVolume = (float) audioManager
.getStreamVolume(AudioManager.STREAM_MUSIC);
float lMaxVolume = (float) audioManager
.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
float lVolume = lActualVolume / lMaxVolume;
// Is the sound loaded already?
if (mSoundIsLoaded) {
mSoundPool.play(mSoundID, lVolume, lVolume, 1, 0, 1f);
I think you have been given plenty of help to figure the random number part out.
You will have to put the sound file in your assets/raw directory.
edit:
I forgot to mention where the mSoundIsLoaded parameter came from.
I set it when my sound has been loaded. I do this in my onCreate method. when the sound is loaded I set the boolean field called mSoundIsLoaded. I do this to prevent NullPointerExceptions when playing the sound
the loading of the sound looks like this:
mSoundPool = new SoundPool(10, AudioManager.STREAM_MUSIC, 0);
mSoundPool.setOnLoadCompleteListener(new OnLoadCompleteListener() {
#Override
public void onLoadComplete(SoundPool soundPool, int sampleId,
int status) {
mSoundIsLoaded = true;
}
});
mSoundID = mSoundPool.load(this, R.raw.sound1, 1);

Soundpool sample not ready

I have a .wav file that I'd like to use across my game, currently I am loading the sound in onCreate() of each activity in the game.
soundCount = soundpool.load(this,R.raw.count, 1);
The sound will be played once the activity starts.
soundpool.play(soundCount, 0.9f, 0.9f, 1, -1, 1f);
Problem is at times I will hit the error "sample x not ready".
Is it possible to load the .wav file once upon starting the game and keep it in memory and use it later across the game? Or is it possible to wait for 1-2 seconds for the sound to load finish?

You'll need to wait for it to finish by adding a listener via SoundPool.setOnLoadCompleteListener.

Since my project is compatible with Android 1.5 and I couldn't use setOnLoadCompleteListener, I resolved making the play of sound delayed.
My source code follows:
playSound_Delayed(soundId, 100);
// (..)
private void playSound_Delayed (final int soundId, final long millisec) {
// TIMER
final Handler mHandler = new Handler();
final Runnable mDelayedTimeTask = new Runnable() {
int counter = 0;
public void run() {
counter++;
if (counter == 1) {
boolean ret = mHandler.postDelayed(this, millisec);
if (ret==false) Log.w("playSound_Delayed", "mHandler.postAtTime FAILED!");
} else {
playSound(soundId);
}
}
};
mDelayedTimeTask.run();
}

you should use setOnLoadCompleteListener if possible ... if not, wrap a while loop around your call to 'play'. something like:
int waitLimit = 1000;
int waitCounter = 0;
int throttle = 10;
while(soundPool.play(soundId, 1.f, 1.f, 1, 0, 1.f) == 0 && waitCounter < waitLimit)
{waitCounter++; SystemClock.sleep(throttle);}
this will retry 'play' 1000 times on a 10ms interval. this should be run on a non-ui thread of course, and is still not ideal. but maybe a little stronger than waiting an arbitrary time and expecting the pool to be ready.

The SoundPool library uses the MediaPlayer service to decode the audio into a raw 16-bit PCM mono or stereo stream which we simply can call preparation of Stream, that takes some times depending on size of sound file. And if we try to play the sound before that process is over, we get "sample x not ready" error.
There are two solutions for this
implement setOnLoadCompleteListener or
wait arbitrary amount of time so that preparation is over
and then play it
Note that there is no exception for this condition or application is not crashing without any try-catch

private SoundPool soundPool;
private int my_sound;
boolean loaded = false;
// In the constructor
soundPool = new SoundPool(10, AudioManager.STREAM_MUSIC, 0);
my_sound = soundPool.load(this, R.raw.blast_sound, 1);
soundPool.setOnLoadCompleteListener(new OnLoadCompleteListener() {
public void onLoadComplete(SoundPool soundPool, int sampleId,int status) {
loaded = true;
}
});
// then where ever you want to play the sound, type
if (loaded) {
soundPool.play(my_sound, 0.9f, 0.9f, 1, 0, 1f);
}

I solved with problem with simple do-while cicle. The method play() return non-zero streamID if successful, zero if failed. So, it's sufficient to check the return value.
int streamID = -1;
do {
streamID = soundPool.play(soundPoolMap.get(index), streamVolume, streamVolume, 1, 0, 1f);
} while(streamID==0);

This would work for you definitely !
public void playWavFile() {
Thread streamThread = new Thread(new Runnable() {
#Override
public void run() {
SoundPool soundPool;
final int wav;
String path = "/mnt/sdcard/AudioRecorder/record.wav";
soundPool = new SoundPool(5,AudioManager.STREAM_MUSIC, 0);
wav = soundPool.load(path, 1);
soundPool.setOnLoadCompleteListener(new OnLoadCompleteListener() {
#Override
public void onLoadComplete(SoundPool soundPool, int sampleId, int status) {
// TODO Auto-generated method stub
soundPool.play(wav,100, 100, 0, 0, 1f);
}
});
}
});
streamThread.start();
}

This sounds crazy, but don't play sounds right away. Give your app a couple of seconds to initialize the SoundPool. In my app, this was exactly the issue; I added a fake "loading" screen of ~3 seconds, and then everything worked. (I didn't even need to preload the sounds.)

Error when playing Media Files

I'm using MediaPlayer to play some sounds files, which at times overlap. I notice that in the LogCat window I keep getting this message:
android max instances of component OMX.TI.ACC. Decode already created.
It seems to have no effect on my application as the sounds continue to play just fine. Does anyone know what this message means, and do I need to worry about it?

SoundPool may be a better option for playing multiple, short sounds.
Creating SoundPool
public static final int SOUND_1 = 1;
public static final int SOUND_2 = 2;
SoundPool mSoundPool;
HashMap<Integer, Integer> mHashMap;
#Override
public void onCreate(Bundle savedInstanceState){
mSoundPool = new SoundPool(2, AudioManager.STREAM_MUSIC, 100);
mSoundMap = new HashMap<Integer, Integer>();
if(mSoundPool != null){
mSoundMap.put(SOUND_1, mSoundPool.load(this, R.raw.sound1, 1));
mSoundMap.put(SOUND_2, mSoundPool.load(this, R.raw.sound2, 1));
}
}
Then play a sound by calling a custom function.
Playing Sound
/*
*Call this function from code with the sound you want e.g. playSound(SOUND_1);
*/
public void playSound(int sound) {
AudioManager mgr = (AudioManager)mContext.getSystemService(Context.AUDIO_SERVICE);
float streamVolumeCurrent = mgr.getStreamVolume(AudioManager.STREAM_MUSIC);
float streamVolumeMax = mgr.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
float volume = streamVolumeCurrent / streamVolumeMax;
if(mSoundPool != null){
mSoundPool.play(mSoundMap.get(sound), volume, volume, 1, 0, 1.0f);
}
}