+/**
+ * This is a reusable equalizer class that lets you get averaged
+ * bands with dB scaling and smoothing.
+ */
+public static class GraphicEQ {
+
+ private final HeronLX lx;
+
+ public final BasicParameter level = new BasicParameter("LVL", 0.5);
+ public final BasicParameter range = new BasicParameter("RNGE", 0.5);
+ public final BasicParameter slope = new BasicParameter("SLOP", 0.5);
+ public final BasicParameter attack = new BasicParameter("ATK", 0.5);
+ public final BasicParameter release = new BasicParameter("REL", 0.5);
+
+ private final FFT fft;
+ private final int numBands;
+
+ private final LinearEnvelope[] bandVals;
+
+ public final static int DEFAULT_NUM_BANDS = 16;
+
+ public GraphicEQ(HeronLX lx) {
+ this(lx, DEFAULT_NUM_BANDS);
+ }
+
+ /**
+ * Note that the number of bands is a suggestion. Due to the FFT implementation
+ * the actual number may be slightly different.
+ */
+ public GraphicEQ(HeronLX lx, int num) {
+ this.lx = lx;
+ fft = new FFT(lx.audioInput().bufferSize(), lx.audioInput().sampleRate());
+ fft.window(FFT.HAMMING);
+ fft.logAverages(50, num/8);
+ numBands = this.fft.avgSize();
+ bandVals = new LinearEnvelope[numBands];
+ for (int i = 0; i < bandVals.length; ++i) {
+ bandVals[i] = new LinearEnvelope(0, 0, 500).trigger();
+ }
+ }
+
+ final float logTen = log(10);
+ public float log10(float val) {
+ return log(val) / logTen;
+ }
+
+ public float getLevel(int band) {
+ return bandVals[band].getValuef();
+ }
+
+ public float getAverageLevel(int minBand, int numBands) {
+ float avg = 0;
+ for (int i = minBand; i < minBand + numBands; ++i) {
+ avg += bandVals[i].getValuef();
+ }
+ avg /= numBands;
+ return avg;
+ }
+
+ public void run(int deltaMs) {
+ fft.forward(lx.audioInput().mix);
+ float zeroDBReference = pow(10, 100*(1-level.getValuef())/20.);
+ float decibelRange = 12 + range.getValuef() * 60;
+ float decibelSlope = slope.getValuef() * 60.f / numBands;
+ for (int i = 0; i < numBands; ++i) {
+ float raw = fft.getAvg(i);
+ float decibels = 20*log10(raw / zeroDBReference);
+ float positiveDecibels = decibels + decibelRange;
+ positiveDecibels += i*decibelSlope;
+ float value = constrain(positiveDecibels / decibelRange, 0, 1);
+
+ if (value > bandVals[i].getValuef()) {
+ bandVals[i].setEndVal(value, attack.getValuef() * 20).trigger();
+ }
+ }
+ for (LinearEnvelope band : bandVals) {
+ band.run(deltaMs);
+ if (!band.isRunning() && band.getValuef() > 0) {
+ band.setEndVal(0, release.getValuef() * 1600).trigger();
+ }
+ }
+ }
+}
+
+