audio-algo-chunkware/audio/algo/chunkware/Limiter.h

107 lines
3.7 KiB
C++

/**
* @author Bojan MARKOVIC
* @author Edouard DUPIN
* @copyright 2006, ChunkWare Music Software, OPEN-SOURCE
* @license BSD-1 (see license file)
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* * The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#ifndef __AUDIO_ALGO_CHUNKWARE_LIMITER_H__
#define __AUDIO_ALGO_CHUNKWARE_LIMITER_H__
#include <etk/types.h>
#include <audio/algo/chunkware/AttRelEnvelope.h>
#include <audio/algo/chunkware/Gain.h>
#include <vector>
namespace audio {
namespace algo {
namespace chunkware {
class Limiter {
public:
Limiter();
virtual ~Limiter() {}
// parameters
virtual void setThresh(double _dB);
virtual void setAttack(double _ms);
virtual void setRelease(double _ms);
virtual double getThresh() const {
return m_threshdB;
}
virtual double getAttack() const {
return m_attack.getTc();
}
virtual double getRelease() const {
return m_release.getTc();
}
// latency
virtual const unsigned int getLatency() const {
return m_peakHold;
}
// sample rate dependencies
virtual void setSampleRate(double _sampleRate);
virtual double getSampleRate() {
return m_attack.getSampleRate();
}
// runtime
// call before runtime (in resume())
virtual void initRuntime();
// limiter runtime process
void process(double& _in1, double& _in2);
protected:
// class for faster attack/release
class FastEnvelope : public audio::algo::chunkware::EnvelopeDetector {
public:
FastEnvelope(double _ms = 1.0, double _sampleRate = 44100.0) :
EnvelopeDetector(_ms, _sampleRate) {
}
virtual ~FastEnvelope() {}
protected:
// override setCoef() - coefficient calculation
virtual void setCoef();
};
private:
// transfer function
double m_threshdB; //!< threshold (dB)
double m_threshold; //!< threshold (linear)
// max peak
unsigned int m_peakHold; //!< peak hold (samples)
unsigned int m_peakTimer; //!< peak hold timer
double m_maxPeak; //!< max peak
// attack/release envelope
audio::algo::chunkware::Limiter::FastEnvelope m_attack; //!< attack
audio::algo::chunkware::Limiter::FastEnvelope m_release; //!< release
double m_overThresholdEnvelope; //!< over-threshold envelope (linear)
// buffer
// BUFFER_SIZE default can handle up to ~10ms at 96kHz
// change this if you require more
static const int BUFFER_SIZE = 1024; //!< buffer size (always a power of 2!)
unsigned int m_bufferMask; //!< buffer mask
unsigned int m_cursor; //!< cursor
std::vector< double > m_outputBuffer[2]; //!< output buffer
};
}
}
}
#endif