Ggtcf

I am devoloping sample application which is taking touch´s X and Y, equiling X to frequency and Y to amplitude. Then calculating simple sin wave and passing that throw thread. When I am generating my sound signal - between writing new data, the reproductor is making crack sound.

I was not working with sound never before, but can guess cracks are due value jump in sin wave, but why its cracking on the end of the track when its guaranteen the value will be zero? so thats why I need help. Crack is heard on the start and on the end of the sound-track.

audioTrack is created in onCreate method. The start() method will start audioTrack.

audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
 sampleRate,
 AudioFormat.CHANNEL_OUT_MONO,
 AudioFormat.ENCODING_PCM_16BIT, numSamples,
 AudioTrack.MODE_STREAM);
 start();

This is my thread:

Runnable m_noiseGenerator = new Runnable() 
 public void run()
 
 Thread.currentThread().setPriority(Thread.MIN_PRIORITY);

 while(!m_stop)
 
 //rnd.nextBytes(noiseData);

 try 
 if(playing) 
 //audioTrack.flush();
 long startTime = System.currentTimeMillis();
 audioTrack.write(generatedSnd, 0, generatedSnd.length);
 if (audioTrack.getPlayState() == audioTrack.PLAYSTATE_STOPPED)
 audioTrack.play();
 long finish = System.currentTimeMillis() - startTime;
 System.out.print("naudioTrackThread: WRITTEN IN " + finish + "msn");
 genToneUpdate = false;
 
 catch (Exception ex) 
 System.out.print("THREAD ERROR " + ex);
 

 try 
 //Thread.sleep(50);
 //Thread.sleep(1000);
 catch (Exception ex) 
 System.out.print("THREAD ERROR sleep " + ex);
 
 
 
;

This is how I am calculating and editing data

for (int i = 0; i < numSamples; i++) 
 samples[i] = ((double) amp / 100) * Math.sin(2 * Math.PI * i * (freq/sampleRate));
 
 int idx = 0;
 for (final double dVal : sample) 
 // scale to maximum amplitude
 final short val = (short) ((dVal * 32767));
 // in 16 bit wav PCM, first byte is the low order byte
 generatedSnd[idx++] = (byte) (val & 0x00ff);
 generatedSnd[idx++] = (byte) ((val & 0xff00) >>> 8);
 genToneUpdate = true;
 

Whole application is avaible here:
soundGenerator application