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/*
* Copyright (C) 2020 Linux Studio Plugins Project <https://lsp-plug.in/>
* (C) 2020 Vladimir Sadovnikov <sadko4u@gmail.com>
*
* This file is part of lsp-dsp-units
* Created on: 25 нояб. 2016 г.
*
* lsp-dsp-units is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* any later version.
*
* lsp-dsp-units is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with lsp-dsp-units. If not, see <https://www.gnu.org/licenses/>.
*/
#ifndef CORE_DYNAMICS_LIMITER_H_
#define CORE_DYNAMICS_LIMITER_H_
#include <lsp-plug.in/dsp-units/version.h>
#include <lsp-plug.in/dsp-units/iface/IStateDumper.h>
#include <lsp-plug.in/dsp-units/util/Delay.h>
#define LIMITER_PATCHES_MAX 256
#define LIMITER_PEAKS_MAX 32
#define LIMITER_LOG_PATCHES_MAX 128
namespace lsp
{
namespace dspu
{
enum limiter_mode_t
{
LM_HERM_THIN,
LM_HERM_WIDE,
LM_HERM_TAIL,
LM_HERM_DUCK,
LM_EXP_THIN,
LM_EXP_WIDE,
LM_EXP_TAIL,
LM_EXP_DUCK,
LM_LINE_THIN,
LM_LINE_WIDE,
LM_LINE_TAIL,
LM_LINE_DUCK
};
class LSP_DSP_UNITS_PUBLIC Limiter
{
private:
Limiter & operator = (const Limiter &);
Limiter(const Limiter &);
protected:
typedef void (*apply_patch_t)(void *patch, float *dst, float amp);
enum update_t
{
UP_SR = 1 << 0,
UP_LK = 1 << 1,
UP_MODE = 1 << 2,
UP_OTHER = 1 << 3,
UP_THRESH = 1 << 4,
UP_ALR = 1 << 5,
UP_ALL = UP_SR | UP_LK | UP_MODE | UP_OTHER | UP_THRESH | UP_ALR
};
typedef struct alr_t
{
float fKS; // Knee start
float fKE; // Knee end
float fGain; // Maximum output gain
float fTauAttack; // Attiack time constant
float fTauRelease; // Release time constant
float vHermite[3]; // Hermite approximation
float fAttack; // Attack
float fRelease; // Release
float fEnvelope; // Envelope
bool bEnable; // Enable ALR
} alr_t;
typedef struct sat_t
{
int32_t nAttack; // Attack
int32_t nPlane; // Plane
int32_t nRelease; // Release
int32_t nMiddle; // Middle
float vAttack[4]; // Hermite interpolation of attack
float vRelease[4]; // Hermite interpolation of release
} sat_t;
typedef struct exp_t
{
int32_t nAttack; // Attack
int32_t nPlane; // Plane
int32_t nRelease; // Release
int32_t nMiddle; // Middle
float vAttack[4]; // Exponent interpolation of attack
float vRelease[4]; // Exponent interpolation of release
} exp_t;
typedef struct line_t
{
int32_t nAttack; // Attack
int32_t nPlane; // Plane
int32_t nRelease; // Release
int32_t nMiddle; // Middle
float vAttack[2]; // Line interpolation of attack
float vRelease[2]; // Line interpolation of release
} line_t;
protected:
float fThreshold;
float fReqThreshold;
float fLookahead;
float fMaxLookahead;
float fAttack;
float fRelease;
float fKnee;
size_t nMaxLookahead;
size_t nLookahead;
size_t nHead;
size_t nMaxSampleRate;
size_t nSampleRate;
size_t nUpdate;
size_t nMode;
alr_t sALR;
// Pre-calculated parameters
float *vGainBuf;
float *vTmpBuf; // Temporary buffer to store the actual sidechain value
uint8_t *vData;
Delay sDelay;
union
{
sat_t sSat; // Hermite mode
exp_t sExp; // Exponent mode
line_t sLine; // Line mode
};
protected:
inline float sat(ssize_t n);
inline float exp(ssize_t n);
inline float line(ssize_t n);
static void apply_sat_patch(sat_t *sat, float *dst, float amp);
static void apply_exp_patch(exp_t *exp, float *dst, float amp);
static void apply_line_patch(line_t *line, float *dst, float amp);
static void reset_sat(sat_t *sat);
static void reset_exp(exp_t *exp);
static void reset_line(line_t *line);
void init_sat(sat_t *sat);
void init_exp(exp_t *exp);
void init_line(line_t *line);
void process_alr(float *gbuf, const float *sc, size_t samples);
static void dump(IStateDumper *v, const char *name, const sat_t *sat);
static void dump(IStateDumper *v, const char *name, const exp_t *exp);
static void dump(IStateDumper *v, const char *name, const line_t *line);
public:
explicit Limiter();
~Limiter();
/**
* Construct the object
*/
void construct();
/** Destroy all data allocated by processor
*
*/
void destroy();
public:
/** Initialize limiter
*
* @param max_sr maximum sample rate that can be passed to limiter
* @param max_lookahead maximum look-ahead time that can be passed to limiter [ms]
* @return true on success
*/
bool init(size_t max_sr, float max_lookahead);
/** Check if limiter is modifier
*
* @return true if limiter settings need to be updated
*/
inline bool modified() const { return nUpdate != 0; }
/** Update settings for limiter
*
*/
void update_settings();
/**
* Get limiter mode
* @return limiter mode
*/
inline limiter_mode_t get_mode() const { return limiter_mode_t(nMode); }
/** Set limiter working mode
*
* @param mode limiter working mode
*/
inline void set_mode(limiter_mode_t mode)
{
if (mode == nMode)
return;
nMode = mode;
nUpdate |= UP_MODE;
}
/** Change current sample rate of processor
*
* @param sr sample rate to set
*/
inline void set_sample_rate(size_t sr)
{
if (sr == nSampleRate)
return;
nSampleRate = sr;
nUpdate |= UP_SR;
}
/** Get threshold
*
* @return threshold
*/
inline float get_threshold() const { return fReqThreshold; }
/** Set limiter threshold
*
* @param thresh limiter threshold
* @param immediate immediately set threshold, no need to perform automated gain lowering
*/
float set_threshold(float thresh, bool immediate);
/**
* Get attack time
* @return attack time
*/
inline float get_attack() const { return fAttack; }
/** Set attack time
*
* @param attack attack time
*/
float set_attack(float attack);
/**
* Get release time
* @return attack time
*/
inline float get_release() const { return fRelease; }
/** Set release time
*
* @param release release time
*/
float set_release(float release);
/**
* Get lookahead time
* @return lookahead time
*/
inline float get_lookahead() const { return fLookahead; }
/** Set look-ahead time
*
* @param lk_ahead look-ahead time
*/
float set_lookahead(float lk_ahead);
/**
* Get maximum possible latency according to the configuration
* @return maximum possible latency
*/
inline size_t max_latency() const { return nMaxLookahead; }
/**
* Get knee of the limiter
* @return knee of the limiter
*/
inline float get_knee() const { return fKnee; }
/** Set knee, the value not greater than 1.0
* If value is 1.0, there is no knee at all
* Other values indicate gain offset below the threshold.
* The same offset above threshold will be automatically calculated.
*
* @param knee knee, 1.0 means no knee
*/
float set_knee(float knee);
/** Get latency of limiter
*
* @return limiter's latency
*/
inline size_t get_latency() const { return nLookahead; }
/**
* Get automatic level regulation attack
* @return automatic level regulation attack
*/
inline float get_alr_attack() const { return sALR.fAttack; }
/**
* Set automatic level regulation attack
* @param attack attack value
* @return previous value
*/
float set_alr_attack(float attack);
/**
* Get automatic level regulation release
* @return automatic level regulation attack
*/
inline float get_alr_release() const { return sALR.fRelease; }
/**
* Set automatic level regulation release
* @param attack attack value
* @return previous value
*/
float set_alr_release(float attack);
/**
* Check that automatic level regulation is turned on
* @return true if automatic level regulation is turned on
*/
inline bool get_alr() const { return sALR.bEnable; }
/** Enable automatic level regulation
*
* @param enable enable flag
* @return previous value
*/
bool set_alr(bool enable);
/** Process data by limiter
*
* @param dst destination buffer with applied delay
* @param gain output gain for VCA
* @param src input signal buffer
* @param sc sidechain input signal
* @param samples number of samples to process
*/
void process(float *dst, float *gain, const float *src, const float *sc, size_t samples);
/**
* Dump internal state
* @param v state dumper
*/
void dump(IStateDumper *v) const;
};
}
} /* namespace lsp */
#endif /* CORE_DYNAMICS_LIMITER_H_ */
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