Android Open Source - SMS-Morse Audio Generator

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From Project

Back to project page SMS-Morse.

License

The source code is released under:

GNU General Public License

Java Source Code

package com.jonathanmackenzie.sms_morse;
/*ww  w . ja  v  a2  s  . co m*/
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioTrack;
import android.util.Log;

public class AudioGenerator {

  private int sampleRate;
  private AudioTrack audioTrack;
  private static final String TAG = AudioGenerator.class.getSimpleName();

  public AudioGenerator(int sampleRate) {
    this.sampleRate = sampleRate;
  }

  public double[] getSineWave(int samples,double frequencyOfTone) {
    double[] sample = new double[samples];
    for (int i = 0; i < samples; i++) {
      sample[i] = Math.sin(2 * Math.PI * i
          / (sampleRate / frequencyOfTone));
    }
    return sample;
  }

  public byte[] get16BitPcm(double[] samples) {
    byte[] generatedSound = new byte[2 * samples.length];
    int index = 0;
    for (double sample : samples) {
      // scale to maximum amplitude
      short maxSample = (short) ((sample * Short.MAX_VALUE));
      // in 16 bit wav PCM, first byte is the low order byte
      generatedSound[index++] = (byte) (maxSample & 0x00ff);
      generatedSound[index++] = (byte) ((maxSample & 0xff00) >>> 8);
    }
    return generatedSound;
  }
  public boolean hasPlayer() {
    return (audioTrack == null);
  }
  public void createPlayer() {
    audioTrack = new AudioTrack(AudioManager.STREAM_NOTIFICATION, sampleRate,
        AudioFormat.CHANNEL_OUT_MONO,
        AudioFormat.ENCODING_PCM_16BIT, sampleRate,
        AudioTrack.MODE_STREAM);
    audioTrack.play();
  }

  public void writeSound(double[] samples) {
    byte[] generatedSnd = get16BitPcm(samples);
    audioTrack.write(generatedSnd, 0, generatedSnd.length);
  }

  public void destroyAudioTrack() {
    Log.d(TAG  ,"Audio track destroyed");
    if(audioTrack == null || audioTrack.getState() == AudioTrack.STATE_UNINITIALIZED)
      return;
    audioTrack.stop();
    audioTrack.release();
  }

  public AudioTrack getAudioTrack() {
    return audioTrack;
  }
}

Java Source Code List

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