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package com.sun.media.sound;

import java.util.Arrays;

A chorus effect made using LFO and variable delay. One for each channel (left,right), with different starting phase for stereo effect.
Author:Karl Helgason
/** * A chorus effect made using LFO and variable delay. One for each channel * (left,right), with different starting phase for stereo effect. * * @author Karl Helgason */
public final class SoftChorus implements SoftAudioProcessor { private static class VariableDelay { private final float[] delaybuffer; private int rovepos = 0; private float gain = 1; private float rgain = 0; private float delay = 0; private float lastdelay = 0; private float feedback = 0; VariableDelay(int maxbuffersize) { delaybuffer = new float[maxbuffersize]; } public void setDelay(float delay) { this.delay = delay; } public void setFeedBack(float feedback) { this.feedback = feedback; } public void setGain(float gain) { this.gain = gain; } public void setReverbSendGain(float rgain) { this.rgain = rgain; } public void processMix(float[] in, float[] out, float[] rout) { float gain = this.gain; float delay = this.delay; float feedback = this.feedback; float[] delaybuffer = this.delaybuffer; int len = in.length; float delaydelta = (delay - lastdelay) / len; int rnlen = delaybuffer.length; int rovepos = this.rovepos; if (rout == null) for (int i = 0; i < len; i++) { float r = rovepos - (lastdelay + 2) + rnlen; int ri = (int) r; float s = r - ri; float a = delaybuffer[ri % rnlen]; float b = delaybuffer[(ri + 1) % rnlen]; float o = a * (1 - s) + b * (s); out[i] += o * gain; delaybuffer[rovepos] = in[i] + o * feedback; rovepos = (rovepos + 1) % rnlen; lastdelay += delaydelta; } else for (int i = 0; i < len; i++) { float r = rovepos - (lastdelay + 2) + rnlen; int ri = (int) r; float s = r - ri; float a = delaybuffer[ri % rnlen]; float b = delaybuffer[(ri + 1) % rnlen]; float o = a * (1 - s) + b * (s); out[i] += o * gain; rout[i] += o * rgain; delaybuffer[rovepos] = in[i] + o * feedback; rovepos = (rovepos + 1) % rnlen; lastdelay += delaydelta; } this.rovepos = rovepos; lastdelay = delay; } public void processReplace(float[] in, float[] out, float[] rout) { Arrays.fill(out, 0); Arrays.fill(rout, 0); processMix(in, out, rout); } } private static class LFODelay { private double phase = 1; private double phase_step = 0; private double depth = 0; private VariableDelay vdelay; private final double samplerate; private final double controlrate; LFODelay(double samplerate, double controlrate) { this.samplerate = samplerate; this.controlrate = controlrate; // vdelay = new VariableDelay((int)(samplerate*4)); vdelay = new VariableDelay((int) ((this.depth + 10) * 2)); } public void setDepth(double depth) { this.depth = depth * samplerate; vdelay = new VariableDelay((int) ((this.depth + 10) * 2)); } public void setRate(double rate) { double g = (Math.PI * 2) * (rate / controlrate); phase_step = g; } public void setPhase(double phase) { this.phase = phase; } public void setFeedBack(float feedback) { vdelay.setFeedBack(feedback); } public void setGain(float gain) { vdelay.setGain(gain); } public void setReverbSendGain(float rgain) { vdelay.setReverbSendGain(rgain); } public void processMix(float[] in, float[] out, float[] rout) { phase += phase_step; while(phase > (Math.PI * 2)) phase -= (Math.PI * 2); vdelay.setDelay((float) (depth * 0.5 * (Math.cos(phase) + 2))); vdelay.processMix(in, out, rout); } public void processReplace(float[] in, float[] out, float[] rout) { phase += phase_step; while(phase > (Math.PI * 2)) phase -= (Math.PI * 2); vdelay.setDelay((float) (depth * 0.5 * (Math.cos(phase) + 2))); vdelay.processReplace(in, out, rout); } } private boolean mix = true; private SoftAudioBuffer inputA; private SoftAudioBuffer left; private SoftAudioBuffer right; private SoftAudioBuffer reverb; private LFODelay vdelay1L; private LFODelay vdelay1R; private float rgain = 0; private boolean dirty = true; private double dirty_vdelay1L_rate; private double dirty_vdelay1R_rate; private double dirty_vdelay1L_depth; private double dirty_vdelay1R_depth; private float dirty_vdelay1L_feedback; private float dirty_vdelay1R_feedback; private float dirty_vdelay1L_reverbsendgain; private float dirty_vdelay1R_reverbsendgain; private float controlrate; public void init(float samplerate, float controlrate) { this.controlrate = controlrate; vdelay1L = new LFODelay(samplerate, controlrate); vdelay1R = new LFODelay(samplerate, controlrate); vdelay1L.setGain(1.0f); // % vdelay1R.setGain(1.0f); // % vdelay1L.setPhase(0.5 * Math.PI); vdelay1R.setPhase(0); globalParameterControlChange(new int[]{0x01 * 128 + 0x02}, 0, 2); } public void globalParameterControlChange(int[] slothpath, long param, long value) { if (slothpath.length == 1) { if (slothpath[0] == 0x01 * 128 + 0x02) { if (param == 0) { // Chorus Type switch ((int)value) { case 0: // Chorus 1 0 (0%) 3 (0.4Hz) 5 (1.9ms) 0 (0%) globalParameterControlChange(slothpath, 3, 0); globalParameterControlChange(slothpath, 1, 3); globalParameterControlChange(slothpath, 2, 5); globalParameterControlChange(slothpath, 4, 0); break; case 1: // Chorus 2 5 (4%) 9 (1.1Hz) 19 (6.3ms) 0 (0%) globalParameterControlChange(slothpath, 3, 5); globalParameterControlChange(slothpath, 1, 9); globalParameterControlChange(slothpath, 2, 19); globalParameterControlChange(slothpath, 4, 0); break; case 2: // Chorus 3 8 (6%) 3 (0.4Hz) 19 (6.3ms) 0 (0%) globalParameterControlChange(slothpath, 3, 8); globalParameterControlChange(slothpath, 1, 3); globalParameterControlChange(slothpath, 2, 19); globalParameterControlChange(slothpath, 4, 0); break; case 3: // Chorus 4 16 (12%) 9 (1.1Hz) 16 (5.3ms) 0 (0%) globalParameterControlChange(slothpath, 3, 16); globalParameterControlChange(slothpath, 1, 9); globalParameterControlChange(slothpath, 2, 16); globalParameterControlChange(slothpath, 4, 0); break; case 4: // FB Chorus 64 (49%) 2 (0.2Hz) 24 (7.8ms) 0 (0%) globalParameterControlChange(slothpath, 3, 64); globalParameterControlChange(slothpath, 1, 2); globalParameterControlChange(slothpath, 2, 24); globalParameterControlChange(slothpath, 4, 0); break; case 5: // Flanger 112 (86%) 1 (0.1Hz) 5 (1.9ms) 0 (0%) globalParameterControlChange(slothpath, 3, 112); globalParameterControlChange(slothpath, 1, 1); globalParameterControlChange(slothpath, 2, 5); globalParameterControlChange(slothpath, 4, 0); break; default: break; } } else if (param == 1) { // Mod Rate dirty_vdelay1L_rate = (value * 0.122); dirty_vdelay1R_rate = (value * 0.122); dirty = true; } else if (param == 2) { // Mod Depth dirty_vdelay1L_depth = ((value + 1) / 3200.0); dirty_vdelay1R_depth = ((value + 1) / 3200.0); dirty = true; } else if (param == 3) { // Feedback dirty_vdelay1L_feedback = (value * 0.00763f); dirty_vdelay1R_feedback = (value * 0.00763f); dirty = true; } if (param == 4) { // Send to Reverb rgain = value * 0.00787f; dirty_vdelay1L_reverbsendgain = (value * 0.00787f); dirty_vdelay1R_reverbsendgain = (value * 0.00787f); dirty = true; } } } } public void processControlLogic() { if (dirty) { dirty = false; vdelay1L.setRate(dirty_vdelay1L_rate); vdelay1R.setRate(dirty_vdelay1R_rate); vdelay1L.setDepth(dirty_vdelay1L_depth); vdelay1R.setDepth(dirty_vdelay1R_depth); vdelay1L.setFeedBack(dirty_vdelay1L_feedback); vdelay1R.setFeedBack(dirty_vdelay1R_feedback); vdelay1L.setReverbSendGain(dirty_vdelay1L_reverbsendgain); vdelay1R.setReverbSendGain(dirty_vdelay1R_reverbsendgain); } } double silentcounter = 1000; public void processAudio() { if (inputA.isSilent()) { silentcounter += 1 / controlrate; if (silentcounter > 1) { if (!mix) { left.clear(); right.clear(); } return; } } else silentcounter = 0; float[] inputA = this.inputA.array(); float[] left = this.left.array(); float[] right = this.right == null ? null : this.right.array(); float[] reverb = rgain != 0 ? this.reverb.array() : null; if (mix) { vdelay1L.processMix(inputA, left, reverb); if (right != null) vdelay1R.processMix(inputA, right, reverb); } else { vdelay1L.processReplace(inputA, left, reverb); if (right != null) vdelay1R.processReplace(inputA, right, reverb); } } public void setInput(int pin, SoftAudioBuffer input) { if (pin == 0) inputA = input; } public void setMixMode(boolean mix) { this.mix = mix; } public void setOutput(int pin, SoftAudioBuffer output) { if (pin == 0) left = output; if (pin == 1) right = output; if (pin == 2) reverb = output; } }