pilotclient/third_party/chunkware_dsp/SimpleLimit.h

/*
 *  Simple Limiter (header)
 *
 *  File        : SimpleLimit.h
 *  Library     : SimpleSource
 *  Version     : 1.12
 *  Class       : SimpleLimit
 *
 *  2006, ChunkWare Music Software, OPEN-SOURCE
 *
 *  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 chunkware_SIMPLE_LIMIT_H
#define chunkware_SIMPLE_LIMIT_H

#include "chunkware_dsp/SimpleHeader.h"       // common header
#include "chunkware_dsp/SimpleEnvelope.h"     // for base class of FastEnvelope
#include "chunkware_dsp/SimpleGain.h"         // for gain functions
#include <vector>

namespace chunkware_simple
{
    //! Simple limiter
    class SimpleLimit
    {
    public:
        //! Ctor
        SimpleLimit();

        //! Dtor
        virtual ~SimpleLimit() {}

        //! @{
        //! set parameters
        virtual void setThresh(double dB);
        virtual void setAttack(double ms) {  this->setAttackImpl(ms); } // used in ctor
        virtual void setRelease(double ms);
        //! @}

        //! @{
        //! get parameters
        virtual double getThresh(void)  const { return threshdB_; }
        virtual double getAttack(void)  const { return att_.getTc(); }
        virtual double getRelease(void) const { return rel_.getTc(); }
        //! @}

        //! get latency
        virtual unsigned int getLatency(void) const { return peakHold_; }

        //! @{
        //! sample rate
        virtual void   setSampleRate(double sampleRate);
        virtual double getSampleRate(void) { return att_.getSampleRate(); }
        //! @}

        //! call before runtime (in resume())
        virtual void initRuntime(void);

        //! limiter runtime process
        void process(double &in1, double &in2);

    protected:

        //! Class for faster attack/release
        class FastEnvelope : public EnvelopeDetector
        {
        public:
            //! Ctor
            FastEnvelope(double ms = 1.0, double sampleRate = 44100.0)
                : EnvelopeDetector(ms, sampleRate)
            {}

            //! Dtor
            virtual ~FastEnvelope() override {}

        protected:
            //! Override setCoef() - coefficient calculation
            virtual void setCoef(void) override;
        };

    private:
        //! Impl. function as it is used in ctor, non virtual
        void setAttackImpl(double ms);

        // transfer function
        double threshdB_;   // threshold (dB)
        double thresh_;     // threshold (linear)

        // max peak
        unsigned int peakHold_;     // peak hold (samples)
        unsigned int peakTimer_;    // peak hold timer
        double maxPeak_;            // max peak

        // attack/release envelope
        FastEnvelope att_;          // attack
        FastEnvelope rel_;          // release
        double env_;                // 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 mask_;                     // buffer mask
        unsigned int cur_;                      // cursor
        std::vector< double > outBuffer_[ 2 ];  // output buffer

    };  // end SimpleLimit class

}   // end namespace chunkware_simple

// include inlined process function
#include "SimpleLimitProcess.inl"

#endif  // guard