AudioTrack-IllegalStateException：在未初始化的AudioTrack上调用play（）

Question

I have a Thread with AudioTrack that I call on button DOWN, on button UP i want to stop the audio. So far so good. My app have Activity A and Activity B. Activity A is some menu from where I start Activity B that is the Main Activity where I call this AudioTrack and so on. Problem is, that everything is working fine until I go to Activity B for the 3rd time, then this happened when i call play.

E/AudioTrack: AudioFlinger could not create track, status: -12
E/AudioTrack-JNI: Error -12 initializing AudioTrack
E/android.media.AudioTrack: Error code -20 when initializing AudioTrack.
java.lang.IllegalStateException: play() called on uninitialized AudioTrack.

For the 1st and 2nd time I don´t even have to call play, just enter the Activity B, but when I want to call play for the 3rd time, this error happened. WHY???

Activity B looks like that

Activity B playTune(){
    if(tuneThread == null){
        tuneThread = new startSI();
        //    tuneThread.setTuneFreq(tuneFreq);
        tuneThread.start();
    }
    return this;
}

void setTuneFreq(double tuneFreq) {
    this.tuneFreq = tuneFreq;
    if(tuneThread != null){
        tuneThread.setTuneFreq(tuneFreq);
    }
}

void stopTune(){
    if(tuneThread != null){
        tuneThread.stopTune();
        tuneThread = null;
    }
}

protected void onPause() {
    stopTune();
    super.onPause();
}

protected void onStop() {
    stopTune();
    super.onStop();

this is how I call and/or stop thread

setTuneFreq(double);

I call in OnSenzorChanged (event Listener) because I need frequency based on data from gyroscope.

playTune();

I call in OnTouchListener after ACTION_DOWN after button is pressed and AudioTrack generate signal as long as it is pressed (until ACTION_UP), then I call

stopTune();

AudioTrack Thread looks like this

public class startSI extends Thread {

    private boolean isRunning;
    private double tuneFreqSI;


    private int sr = 44100;
    private int sibuffsize = AudioTrack.getMinBufferSize(sr,
            AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT);
    private AudioTrack siaudioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
            sr, AudioFormat.CHANNEL_OUT_MONO,
            AudioFormat.ENCODING_PCM_16BIT, sibuffsize,
            AudioTrack.MODE_STREAM);


    @Override
    public void run() {

        super.run();
        isRunning = true;


        short samples[] = new short[sibuffsize];
        int amp = 32767;
        double twopi = 8. * Math.atan(1.);
        double ph = 0.0;

        try {

        siaudioTrack.play();

        } catch(IllegalStateException e) {
            System.out.println("error play "+e);   
        }

        while (isRunning) {

            double fr = tuneFreqSI;
            double fLFO = frLFO;
            for (int i = 0; i < sibuffsize; i++) {
                samples[i] = (short) (amp * Math.sin(ph));
                ph += twopi * fr / sr;               
            }
            siaudioTrack.write(samples, 0, sibuffsize);       

        }
        try {
        siaudioTrack.stop();
        siaudioTrack.release();

        }catch(IllegalStateException e) {
            System.out.println("error stop "+e);
        }

    }

    public void setTuneFreq(double tuneFreq, double frLFO, double ampLFO) {

        this.tuneFreqSI = tuneFreq;
        this.frLFO = frLFO;
        this.ampLFO = ampLFO;
    }


    public void stopTune() {
        isRunning = false;

        try {
            this.join();
            this.interrupt();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

I need to start this thread even after I open Activity B for the 3rd time.

What Am I doing wrong?

Answer 1

I think, that your Audio Track is destroyed by Garbage Collector in meantime. So I suggest you to reinitialize the siaudioTrack at the very begginning of run() method using this line.

this.siaudioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, sr, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT, sibuffsize, AudioTrack.MODE_STREAM);