Audio Synthesis with android AudioTrack - 1

Readme

This is includes both the naive and the most advanced implementation.
The AudioGenerator class can be found here: https://github.com/MasterEx/BeatKeeper/blob/master/src/pntanasis/android/metronome/AudioGenerator.java

Code was crafted by Periklis Master_ex Ntanasis <pntanasis@gmail.com> 2012

Frequencies were found here: http://www.phy.mtu.edu/~suits/notefreqs.html

Partitura was found here: 

AdvancedAudioSynthesisDemoActivity.java

package pntanasis.master_ex.android;

import pntanasis.master_ex.android.Synthesizer.Note0;
import android.app.Activity;
import android.os.Bundle;

public class AudioSynthesisDemoActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        Synthesizer synthesizer = new Synthesizer();
        
        synthesizer.play(Note0.C, 5, 1.0/8);
        synthesizer.play(Note0.E, 5, 1.0/8);
        
        synthesizer.play(Note0.F, 5, 1.0/4);        
        synthesizer.play(Note0.A, 5, 1.0/4);        
        synthesizer.play(Note0.A, 5, 3.0/8);        
        synthesizer.play(Note0.B, 5, 1.0/8);
        
        synthesizer.play(Note0.A, 5, 1.0/4);
        synthesizer.play(Note0.F, 5, 1.0/4);
        synthesizer.play(Note0.C, 5, 3.0/8);
        synthesizer.play(Note0.E, 5, 1.0/8);
        
        synthesizer.play(Note0.F, 5, 1.0/4);
        synthesizer.play(Note0.F, 5, 1.0/4);
        synthesizer.play(Note0.E, 5, 1.0/4);
        synthesizer.play(Note0.C, 5, 1.0/4);
        
        synthesizer.play(Note0.E, 5, 3.0/4);
        synthesizer.play(Note0.C, 5, 1.0/8);        
        synthesizer.play(Note0.E, 5, 1.0/8);
        
        synthesizer.play(Note0.F, 5, 1.0/4);        
        synthesizer.play(Note0.A, 5, 1.0/4);        
        synthesizer.play(Note0.A, 5, 3.0/8);        
        synthesizer.play(Note0.B, 5, 1.0/8);
        
        synthesizer.play(Note0.A, 5, 1.0/4);
        synthesizer.play(Note0.F, 5, 1.0/4);
        synthesizer.play(Note0.C, 5, 3.0/8);
        synthesizer.play(Note0.E, 5, 1.0/8);
        
        synthesizer.play(Note0.F, 5, 1.0/4);
        synthesizer.play(Note0.F, 5, 1.0/4);
        synthesizer.play(Note0.E, 5, 1.0/4);
        synthesizer.play(Note0.C, 5, 1.0/4);
        
        synthesizer.play(Note0.C, 5, 1);
        
        synthesizer.stop();
        
    }
}

AudioSynthesisDemoActivity.java

package pntanasis.master_ex.android;

import android.app.Activity;
import android.os.Bundle;

public class AudioSynthesisDemoActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        AudioGenerator audio = new AudioGenerator(8000);
        
        double[] silence = audio.getSineWave(200, 8000, 0);
        
        int noteDuration = 2400;
        
        double[] doNote = audio.getSineWave(noteDuration/2, 8000, 523.25);
        double[] reNote = audio.getSineWave(noteDuration/2, 8000, 587.33);
        double[] faNote = audio.getSineWave(noteDuration, 8000, 698.46);
        double[] laNote = audio.getSineWave(noteDuration, 8000, 880.00);
        double[] laNote2 = audio.getSineWave((int) (noteDuration*1.25), 8000, 880.00);
        double[] siNote = audio.getSineWave(noteDuration/2, 8000, 987.77);
        double[] doNote2 = audio.getSineWave((int) (noteDuration*1.25), 8000, 523.25);
        double[] miNote = audio.getSineWave(noteDuration/2, 8000, 659.26);
        double[] miNote2 = audio.getSineWave(noteDuration, 8000, 659.26);
        double[] doNote3 = audio.getSineWave(noteDuration, 8000, 523.25);
        double[] miNote3 = audio.getSineWave(noteDuration*3, 8000, 659.26);
        double[] reNote2 = audio.getSineWave(noteDuration*4, 8000, 587.33);
        
        audio.createPlayer();
        audio.writeSound(doNote);
        audio.writeSound(silence);
        audio.writeSound(reNote);
        audio.writeSound(silence);
        audio.writeSound(faNote);
        audio.writeSound(silence);
        audio.writeSound(laNote);
        audio.writeSound(silence);
        audio.writeSound(laNote2);
        audio.writeSound(silence);
        audio.writeSound(siNote);
        audio.writeSound(silence);
        audio.writeSound(laNote);
        audio.writeSound(silence);
        audio.writeSound(faNote);
        audio.writeSound(silence);
        audio.writeSound(doNote2);
        audio.writeSound(silence);
        audio.writeSound(miNote);
        audio.writeSound(silence);
        audio.writeSound(faNote);
        audio.writeSound(silence);
        audio.writeSound(faNote);
        audio.writeSound(silence);
        audio.writeSound(miNote2);
        audio.writeSound(silence);
        audio.writeSound(doNote3);
        audio.writeSound(silence);
        audio.writeSound(miNote3);
        audio.writeSound(silence);        
        audio.writeSound(doNote);
        audio.writeSound(silence);
        audio.writeSound(reNote);
        audio.writeSound(silence);
        audio.writeSound(faNote);
        audio.writeSound(silence);
        audio.writeSound(laNote);
        audio.writeSound(silence);
        audio.writeSound(laNote2);
        audio.writeSound(silence);
        audio.writeSound(siNote);
        audio.writeSound(silence);
        audio.writeSound(laNote);
        audio.writeSound(silence);
        audio.writeSound(faNote);
        audio.writeSound(silence);
        audio.writeSound(doNote2);
        audio.writeSound(silence);
        audio.writeSound(miNote);
        audio.writeSound(silence);
        audio.writeSound(faNote);
        audio.writeSound(silence);
        audio.writeSound(faNote);
        audio.writeSound(silence);
        audio.writeSound(miNote2);
        audio.writeSound(silence);
        audio.writeSound(miNote2);
        audio.writeSound(silence);
        audio.writeSound(reNote2);
        
        audio.destroyAudioTrack();
        
    }
}

Synthesizer.java

package pntanasis.master_ex.android;

public class Synthesizer {
	
	private final short silenceDuration = 200;
	private final short noteDuration = 2400;
	private AudioGenerator audio = new AudioGenerator(8000);
	
	public enum Note0 {
		
		C(16.35),
		Csharp(17.32),
		D(18.35),
		Dsharp(19.45),
		E(20.60),
		F(21.83),
		Fsharp(23.12),
		G(24.50),
		Gsharp(25.96),
		A(27.50),
		Asharp(29.14),
		B(30.87);
		
		private final double frequency;
		
		Note0(double frequency) {
			this.frequency = frequency;
		}
		
		public double getFrequency() {
			return frequency;
		}
	}
	
	Synthesizer() {
		audio.createPlayer();
	}
	
	public void play(Note0 note,int octave,double duration) {
		audio.writeSound(audio.getSineWave((int) (noteDuration*duration*4), 8000, note.getFrequency()*Math.pow(2, octave)));
		audio.writeSound(audio.getSineWave(silenceDuration, 8000, 0));
	}
	
	public void stop() {
		audio.destroyAudioTrack();
	}

}