audio-drain/drain/Equalizer.h

96 lines
2.7 KiB
C++

/** @file
* @author Edouard DUPIN
* @copyright 2011, Edouard DUPIN, all right reserved
* @license APACHE v2.0 (see license file)
*/
#ifndef __DRAIN_ALGO_EQUALIZER_H__
#define __DRAIN_ALGO_EQUALIZER_H__
#include <drain/Algo.h>
#include <etk/memory.h>
namespace drain {
enum filterType {
filterType_none, //!< no filter (pass threw...)
filterType_lowPass, //!< low pass filter
filterType_highPass, //!< High pass filter
filterType_bandPass, //!< band pass filter
filterType_notch, //!< Notch Filter
filterType_peak, //!< Peaking band EQ filter
filterType_lowShelf, //!< Low shelf filter
filterType_highShelf, //!< High shelf filter
};
class BGHistory {
public:
BGHistory() {
m_x[0] = 0;
m_y[1] = 0;
m_x[0] = 0;
m_y[1] = 0;
}
float m_x[2]; //!< X history
float m_y[2]; //!< Y histiry
};
class Equalizer : public Algo {
protected:
/**
* @brief Constructor
*/
Equalizer();
void init();
public:
static std11::shared_ptr<Equalizer> create();
/**
* @brief Destructor
*/
virtual ~Equalizer();
protected:
virtual void configurationChange();
public:
virtual bool process(std11::chrono::system_clock::time_point& _time,
void* _input,
size_t _inputNbChunk,
void*& _output,
size_t& _outputNbChunk);
virtual bool setParameter(const std::string& _parameter, const std::string& _value);
virtual std::string getParameter(const std::string& _parameter) const;
virtual std::string getParameterProperty(const std::string& _parameter) const;
protected:
float processFloat(float _sample, drain::BGHistory& _history);
//-----------------------------------------
// START parameters:
enum filterType m_type; //!< current filter type.
float m_gain; //!< Gain to apply in dB ??? limit : -30, +30
float m_frequencyCut; //!< Frequency to apply filter ???? LIMIT : [0..sampleRate/2]
// good value of 0.707 ==> permit to not ower gain
float m_qualityFactor; //!< Quality factor ??? limit [0.01 .. 10]
// END parameters:
//-----------------------------------------
float m_a[3]; //!< A bi-Quad coef
float m_b[2]; //!< B bi-Quad coef
std::vector<BGHistory> m_history;
/**
* @brief Configure the current biquad.
*/
bool configureBiQuad();
public:
/**
* @brief Configure the current biquad.
*/
void calcBiquad(enum drain::filterType _type, double _frequencyCut, double _qualityFactor, double _gain);
std::vector<float> getCoef() {
std::vector<float> out;
out.push_back(m_a[0]);
out.push_back(m_a[1]);
out.push_back(m_a[2]);
out.push_back(m_b[0]);
out.push_back(m_b[1]);
return out;
}
};
};
#endif