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//=============================================================================
// MuseScore
// Music Composition & Notation
//
// Copyright (C) 2015 Werner Schweer
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2
// as published by the Free Software Foundation and appearing in
// the file LICENCE.GPL
//=============================================================================
#ifndef __COMPRESSOR_H__
#define __COMPRESSOR_H__
#include "effects/effect.h"
namespace Ms {
#define RMS_BUF_SIZE 64
static const int A_TBL = 256;
//---------------------------------------------------------
// RmsEnv
//---------------------------------------------------------
class RmsEnv {
float buffer[RMS_BUF_SIZE];
unsigned int pos;
float sum;
public:
RmsEnv() {
for (int i=0; i<RMS_BUF_SIZE; i++)
buffer[i] = 0.0f;
pos = 0;
sum = 0.0f;
}
float process(const float x) {
sum -= buffer[pos];
sum += x;
if (sum < 1.0e-6)
sum = 0.0f;
buffer[pos] = x;
pos = (pos + 1) & (RMS_BUF_SIZE - 1);
return sqrt(sum / (float)RMS_BUF_SIZE);
}
};
//---------------------------------------------------------
// Compressor
//---------------------------------------------------------
class Compressor : public Effect
{
Q_OBJECT
float sampleRate;
RmsEnv rms;
float sum;
float amp;
float gain;
float gain_t;
float env;
float env_rms;
float env_peak;
unsigned int count;
float as[A_TBL];
// The blanace between the RMS and peak envelope followers.
// RMS is generally better for subtle, musical compression and peak is better for heavier,
// fast compression and percussion.
// <range min="0" max="1"/>
float rms_peak { .5 };
// Attack time (ms)
//The attack time in milliseconds.
// <range min="1.5" max="400"/>
float _attack {1.5 }; // 1.5 - 400 (ms)
// <port label="release" dir="input" type="control" hint="default_middle">
// Release time (ms)
// The release time in milliseconds.
// <range min="2" max="800"/>
float _release = 400;
// <port label="threshold" dir="input" type="control" hint="default_maximum">
// Threshold level (dB)
// The point at which the compressor will start to kick in.
// <range min="-30" max="0"/>
float _threshold = -10;
// Ratio (1:n)
// The gain reduction ratio used when the signal level exceeds the threshold.
// <range min="1" max="20"/>
float _ratio = 5;
// <port label="knee" dir="input" type="control" hint="default_low">
// Knee radius (dB)
// The distance from the threshold where the knee curve starts.
// <range min="1" max="10"/>
float _knee = 1.0;
// Amplitude (dB)
// The level of the input signal, in decibels.
// <range min="-40" max="+12"/>
// float amplitude = 0.0;
// Gain reduction (dB)
// The degree of gain reduction applied to the input signal, in decibels.
// <range min="-24" max="0"/>
// float gain_red = -20;
float _makeupGain = 1.0;
void setRmsPeak(float v) { rms_peak = v; }
void setAttack(float v) { _attack = v; }
void setRelease(float v) { _release = v; }
void setThreshold(float v) { _threshold = v; }
void setRatio(float v) { _ratio = v; }
void setKnee(float v) { _knee = v; }
void setMakeupGain(float v) { _makeupGain = v; }
float rmsPeak() const { return rms_peak; }
float attack() const { return _attack; }
float release() const { return _release; }
float threshold() const { return _threshold; }
float ratio() const { return _ratio; }
float knee() const { return _knee; }
float makeupGain() const { return _makeupGain; }
public:
virtual void init(float fsamp);
virtual void process(int n, float* inp, float* out);
virtual const char* name() const { return "SC4"; }
virtual EffectGui* gui();
virtual const std::vector<ParDescr>& parDescr() const;
virtual void setNValue(int parameter, double value);
virtual double nvalue(int idx) const;
virtual SynthesizerGroup state() const;
virtual void setState(const SynthesizerGroup&);
};
}
#endif
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