OpenAudio_ArduinoLibrary/AudioEffectCompWDRC_F32.h

/*
 * AudioEffectCompWDR_F32: Wide Dynamic Rnage Compressor
 * 
 * Created: Chip Audette (OpenAudio) Feb 2017
 * Derived From: WDRC_circuit from CHAPRO from BTNRC: https://github.com/BTNRH/chapro
 *     As of Feb 2017, CHAPRO license is listed as "Creative Commons?"
 * 
 * MIT License.  Use at your own risk.
 * 
 */

#ifndef _AudioEffectCompWDRC_F32
#define _AudioEffectCompWDRC_F32

class AudioCalcGainWDRC_F32;  //forward declared.  Actually defined in later header file, but I need this here to avoid circularity

#include <Arduino.h>
#include <AudioStream_F32.h>
#include <arm_math.h>
#include <AudioCalcEnvelope_F32.h>
#include <AudioCalcGainWDRC_F32.h>  //has definition of CHA_WDRC
#include "BTNRH_WDRC_Types.h"
//#include "utility/textAndStringUtils.h"


class AudioEffectCompWDRC_F32 : public AudioStream_F32
{
	//GUI: inputs:1, outputs:1  //this line used for automatic generation of GUI node
	//GUI: shortName: CompressWDRC
  public:
    AudioEffectCompWDRC_F32(void): AudioStream_F32(1,inputQueueArray) { //need to modify this for user to set sample rate
      setSampleRate_Hz(AUDIO_SAMPLE_RATE);
      setDefaultValues();
    }

    AudioEffectCompWDRC_F32(AudioSettings_F32 settings): AudioStream_F32(1,inputQueueArray) { //need to modify this for user to set sample rate
      setSampleRate_Hz(settings.sample_rate_Hz);
      setDefaultValues();
    }

    //here is the method called automatically by the audio library
    void update(void) {
      //receive the input audio data
      audio_block_f32_t *block = AudioStream_F32::receiveReadOnly_f32();
      if (!block) return;
      
      //allocate memory for the output of our algorithm
      audio_block_f32_t *out_block = AudioStream_F32::allocate_f32();
      if (!out_block) return;
      
      //do the algorithm
      compress(block->data, out_block->data, block->length);
      
      // transmit the block and release memory
      AudioStream_F32::transmit(out_block); // send the FIR output
      AudioStream_F32::release(out_block);
      AudioStream_F32::release(block);
    }


    //here is the function that does all the work
    //void cha_agc_channel(float *input, float *output, int cs) {  
    //  //compress(input, output, cs, &prev_env,
    //  //  CHA_DVAR.alfa, CHA_DVAR.beta, CHA_DVAR.tkgain, CHA_DVAR.tk, CHA_DVAR.cr, CHA_DVAR.bolt, CHA_DVAR.maxdB);
    //  compress(input, output, cs);
    //}

    //void compress(float *x, float *y, int n, float *prev_env,
    //    float &alfa, float &beta, float &tkgn, float &tk, float &cr, float &bolt, float &mxdB)
     void compress(float *x, float *y, int n)    
     //x, input, audio waveform data
     //y, output, audio waveform data after compression
     //n, input, number of samples in this audio block
    {        
        // find smoothed envelope
        audio_block_f32_t *envelope_block = AudioStream_F32::allocate_f32();
        if (!envelope_block) return;
        calcEnvelope.smooth_env(x, envelope_block->data, n);
        //float *xpk = envelope_block->data; //get pointer to the array of (empty) data values

        //calculate gain
        audio_block_f32_t *gain_block = AudioStream_F32::allocate_f32();
        if (!gain_block) return;
        calcGain.calcGainFromEnvelope(envelope_block->data, gain_block->data, n);
        
        //apply gain
        arm_mult_f32(x, gain_block->data, y, n);

        // release memory
        AudioStream_F32::release(envelope_block);
        AudioStream_F32::release(gain_block);
    }


    void setDefaultValues(void) {
      //set default values...configure as limitter
      BTNRH_WDRC::CHA_WDRC gha = {
		5.0f, // attack time (ms)
        50.0f,     // release time (ms)
        24000.0f,  // fs, sampling rate (Hz), THIS IS IGNORED!
        115.0f,    // maxdB, maximum signal (dB SPL)...assumed SPL for full-scale input signal
        0.0f,      // tkgain, compression-start gain (dB)
        55.0f,    // tk, compression-start kneepoint (dB SPL)
        1.0f,     // cr, compression ratio  (set to 1.0 to defeat)
        100.0f     // bolt, broadband output limiting threshold (ie, the limiter. SPL. 10:1 comp ratio)
      };
      setParams_from_CHA_WDRC(&gha);
    }

    //set all of the parameters for the compressor using the CHA_WDRC structure
    //assumes that the sample rate has already been set!!!
    void setParams_from_CHA_WDRC(BTNRH_WDRC::CHA_WDRC *gha) {
      //configure the envelope calculator...assumes that the sample rate has already been set!
      calcEnvelope.setAttackRelease_msec(gha->attack,gha->release); //these are in milliseconds

      //configure the compressor
      calcGain.setParams_from_CHA_WDRC(gha);
    }

    //set all of the user parameters for the compressor
    //assumes that the sample rate has already been set!!!
    void setParams(float attack_ms, float release_ms, float maxdB, float tkgain, float comp_ratio, float tk, float bolt) {
      
      //configure the envelope calculator...assumes that the sample rate has already been set!
      calcEnvelope.setAttackRelease_msec(attack_ms,release_ms);

      //configure the WDRC gains
      calcGain.setParams(maxdB, tkgain, comp_ratio, tk, bolt);
    }

    void setSampleRate_Hz(const float _fs_Hz) {
      //pass this data on to its components that care
      given_sample_rate_Hz = _fs_Hz;
      calcEnvelope.setSampleRate_Hz(_fs_Hz);
    }
	
	void setAttackRelease_msec(const float atk_msec, const float rel_msec) {
		calcEnvelope.setAttackRelease_msec(atk_msec, rel_msec);
	}
	
	void setKneeLimiter_dBSPL(float _bolt) { calcGain.setKneeLimiter_dBSPL(_bolt); }
	void setKneeLimiter_dBFS(float _bolt_dBFS) {  calcGain.setKneeLimiter_dBFS(_bolt_dBFS); }
	void setGain_dB(float _gain_dB) { calcGain.setGain_dB(_gain_dB); } //gain at start of compression
	void setKneeCompressor_dBSPL(float _tk) { calcGain.setKneeCompressor_dBSPL(_tk); }
	void setKneeCompressor_dBFS(float _tk_dBFS) { calcGain.setKneeCompressor_dBFS(_tk_dBFS); }
	void setCompRatio(float _cr) { calcGain.setCompRatio(_cr); }
	void setMaxdB(float _maxdB) { calcGain.setMaxdB(_maxdB); };

    float getCurrentLevel_dB(void) { return AudioCalcGainWDRC_F32::db2(calcEnvelope.getCurrentLevel()); }  //this is 20*log10(abs(signal)) after the envelope smoothing

    float getGain_dB(void) { return calcGain.getGain_dB(); }	//returns the linear gain of the system
	float getCurrentGain(void) { return calcGain.getCurrentGain(); }
	float getCurrentGain_dB(void) { return calcGain.getCurrentGain_dB(); }
	
    AudioCalcEnvelope_F32 calcEnvelope;
    AudioCalcGainWDRC_F32 calcGain;
    
  private:
    audio_block_f32_t *inputQueueArray[1];
    float given_sample_rate_Hz;
};


#endif