plectrum

Plectrum: instrument tuner for Android
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GainProcessor.java (1997B)

      1 /*
      2 *      _______                       _____   _____ _____  
      3 *     |__   __|                     |  __ \ / ____|  __ \ 
      4 *        | | __ _ _ __ ___  ___  ___| |  | | (___ | |__) |
      5 *        | |/ _` | '__/ __|/ _ \/ __| |  | |\___ \|  ___/ 
      6 *        | | (_| | |  \__ \ (_) \__ \ |__| |____) | |     
      7 *        |_|\__,_|_|  |___/\___/|___/_____/|_____/|_|     
      8 *                                                         
      9 * -------------------------------------------------------------
     10 *
     11 * TarsosDSP is developed by Joren Six at IPEM, University Ghent
     12 *  
     13 * -------------------------------------------------------------
     14 *
     15 *  Info: http://0110.be/tag/TarsosDSP
     16 *  Github: https://github.com/JorenSix/TarsosDSP
     17 *  Releases: http://0110.be/releases/TarsosDSP/
     18 *  
     19 *  TarsosDSP includes modified source code by various authors,
     20 *  for credits and info, see README.
     21 * 
     22 */
     23 
     24 
     25 package be.tarsos.dsp;
     26 
     27 /**
     28  * With the gain processor it is possible to adapt the volume of the sound. With
     29  * a gain of 1, nothing happens. A gain greater than one is a volume increase a
     30  * gain between zero and one, exclusive, is a decrease. If you need to flip the
     31  * sign of the audio samples, you can by providing a gain of -1.0. but I have no
     32  * idea what you could gain by doing that (pathetic pun, I know).
     33  * 
     34  * @author Joren Six
     35  */
     36 public class GainProcessor implements AudioProcessor {
     37 	private double gain;
     38 	
     39 	public GainProcessor(double newGain) {
     40 		setGain(newGain);
     41 	}
     42 
     43 	public void setGain(double newGain) {
     44 		this.gain = newGain;
     45 	}
     46 
     47 	@Override
     48 	public boolean process(AudioEvent audioEvent) {
     49 		float[] audioFloatBuffer = audioEvent.getFloatBuffer();
     50 		for (int i = audioEvent.getOverlap(); i < audioFloatBuffer.length ; i++) {
     51 			float newValue = (float) (audioFloatBuffer[i] * gain);
     52 			if(newValue > 1.0f) {
     53 				newValue = 1.0f;
     54 			} else if(newValue < -1.0f) {
     55 				newValue = -1.0f;
     56 			}
     57 			audioFloatBuffer[i] = newValue;
     58 		}
     59 		return true;
     60 	}
     61 	
     62 	@Override
     63 	public void processingFinished() {
     64 		// NOOP
     65 	}
     66 }