FFTTest.java

/*
*      _______                       _____   _____ _____  
*     |__   __|                     |  __ \ / ____|  __ \ 
*        | | __ _ _ __ ___  ___  ___| |  | | (___ | |__) |
*        | |/ _` | '__/ __|/ _ \/ __| |  | |\___ \|  ___/ 
*        | | (_| | |  \__ \ (_) \__ \ |__| |____) | |     
*        |_|\__,_|_|  |___/\___/|___/_____/|_____/|_|     
*                                                         
* -------------------------------------------------------------
*
* TarsosDSP is developed by Joren Six at IPEM, University Ghent
*  
* -------------------------------------------------------------
*
*  Info: http://0110.be/tag/TarsosDSP
*  Github: https://github.com/JorenSix/TarsosDSP
*  Releases: http://0110.be/releases/TarsosDSP/
*  
*  TarsosDSP includes modified source code by various authors,
*  for credits and info, see README.
* 
*/


package be.tarsos.dsp.test;

import static org.junit.Assert.assertEquals;

import java.io.ByteArrayInputStream;

import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.UnsupportedAudioFileException;

import org.junit.Test;

import be.tarsos.dsp.AudioDispatcher;
import be.tarsos.dsp.AudioEvent;
import be.tarsos.dsp.AudioProcessor;
import be.tarsos.dsp.io.TarsosDSPAudioFloatConverter;
import be.tarsos.dsp.io.TarsosDSPAudioFormat;
import be.tarsos.dsp.io.jvm.AudioPlayer;
import be.tarsos.dsp.io.jvm.JVMAudioInputStream;
import be.tarsos.dsp.util.fft.FFT;

public class FFTTest {
	/**
	 * Constructs and returns a buffer of a two seconds long pure sine of 440Hz
	 * sampled at 44.1kHz.
	 * 
	 * @return A buffer of a two seconds long pure sine (440Hz) sampled at
	 *         44.1kHz.
	 */
	public static float[] testAudioBufferSine() {
		final double sampleRate = 44100.0;
		final double f0 = 440.0;
		final double amplitudeF0 = 0.5;
		final double seconds = 2.0;
		final float[] buffer = new float[(int) (seconds * sampleRate)];
		for (int sample = 0; sample < buffer.length; sample++) {
			final double time = sample / sampleRate;
			buffer[sample] = (float) (amplitudeF0 * Math.sin(2 * Math.PI * f0 * time));
		}
		return buffer;
	}
	
	@Test
	public void testForwardAndBackwardsFFT() throws UnsupportedAudioFileException, LineUnavailableException{		
		  final float[] floatBuffer = testAudioBufferSine();
	      final TarsosDSPAudioFormat format = new TarsosDSPAudioFormat(44100, 16, 1, true, false);
	      final TarsosDSPAudioFloatConverter converter =  TarsosDSPAudioFloatConverter.getConverter(format);
	      final byte[] byteBuffer = new byte[floatBuffer.length * format.getFrameSize()];
	      assertEquals("Specified 16 bits so framesize should be 2.", 2, format.getFrameSize());
	      converter.toByteArray(floatBuffer, byteBuffer);
	      final ByteArrayInputStream bais = new ByteArrayInputStream(byteBuffer);
          final AudioInputStream inputStream = new AudioInputStream(bais, JVMAudioInputStream.toAudioFormat(format),floatBuffer.length);
          JVMAudioInputStream stream = new JVMAudioInputStream(inputStream);
          final AudioDispatcher dispatcher = new AudioDispatcher(stream, 1024, 0);
          dispatcher.addAudioProcessor(new AudioProcessor() {
			private FFT  fft = new FFT(512);
			@Override
			public void processingFinished() {
			}
			
	
			@Override
			public boolean process(AudioEvent audioEvent) {
				float[] audioFloatBuffer = audioEvent.getFloatBuffer();
				fft.forwardTransform(audioFloatBuffer);
				fft.backwardsTransform(audioFloatBuffer);
				return true;
			}
		});

        dispatcher.addAudioProcessor(new AudioPlayer(JVMAudioInputStream.toAudioFormat(format)));
        dispatcher.run();
	}
}