/*
	SuperCollider real time audio synthesis system
 Copyright (c) 2002 James McCartney. All rights reserved.
	http://www.audiosynth.com

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

 This program 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 General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 */

//Nick Collins 8 Nov 2007
//loudness model


#include "ML.h"

//perhaps need to have sampling rate choice here: but then, double rate, double fft size, only use bottom 1024 again as useful spectrum in human hearing range! So should just work?
int eqlbandbins[43]= {1,2,3,4,5,6,7,8,9,11,13,15,17,19,22,25,28,32,36,41,46,52,58,65,73,82,92,103,116,129,144,161,180,201,225,251,280,312,348,388,433,483,513};
int eqlbandsizes[42]= {1,1,1,1,1,1,1,1,2,2,2,2,2,3,3,3,4,4,5,5,6,6,7,8,9,10,11,13,13,15,17,19,21,24,26,29,32,36,40,45,50,29}; //was 30

float contours[42][11]= {{ 47.88, 59.68, 68.55, 75.48, 81.71, 87.54, 93.24, 98.84,104.44,109.94,115.31},{ 29.04, 41.78, 51.98, 60.18, 67.51, 74.54, 81.34, 87.97, 94.61,101.21,107.74},{ 20.72, 32.83, 43.44, 52.18, 60.24, 67.89, 75.34, 82.70, 89.97, 97.23,104.49},{ 15.87, 27.14, 37.84, 46.94, 55.44, 63.57, 71.51, 79.34, 87.14, 94.97,102.37},{ 12.64, 23.24, 33.91, 43.27, 52.07, 60.57, 68.87, 77.10, 85.24, 93.44,100.90},{ 10.31, 20.43, 31.03, 40.54, 49.59, 58.33, 66.89, 75.43, 83.89, 92.34,100.80},{  8.51, 18.23, 28.83, 38.41, 47.65, 56.59, 65.42, 74.16, 82.89, 91.61,100.33},{  7.14, 16.55, 27.11, 36.79, 46.16, 55.27, 64.29, 73.24, 82.15, 91.06, 99.97},{  5.52, 14.58, 25.07, 34.88, 44.40, 53.73, 62.95, 72.18, 81.31, 90.44, 99.57},{  3.98, 12.69, 23.10, 32.99, 42.69, 52.27, 61.66, 71.15, 80.54, 89.93, 99.31},{  2.99, 11.43, 21.76, 31.73, 41.49, 51.22, 60.88, 70.51, 80.11, 89.70, 99.30},{  2.35, 10.58, 20.83, 30.86, 40.68, 50.51, 60.33, 70.08, 79.83, 89.58, 99.32},{  2.05, 10.12, 20.27, 30.35, 40.22, 50.10, 59.97, 69.82, 79.67, 89.52, 99.38},{  2.00,  9.93, 20.00, 30.07, 40.00, 49.93, 59.87, 69.80, 79.73, 89.67, 99.60},{  2.19, 10.00, 20.00, 30.00, 40.00, 50.00, 59.99, 69.99, 79.98, 89.98, 99.97},{  2.71, 10.56, 20.61, 30.71, 40.76, 50.81, 60.86, 70.96, 81.01, 91.06,101.17},{  3.11, 11.05, 21.19, 31.41, 41.53, 51.64, 61.75, 71.95, 82.05, 92.15,102.33},{  2.39, 10.69, 21.14, 31.52, 41.73, 51.95, 62.11, 72.31, 82.46, 92.56,102.59},{  1.50, 10.11, 20.82, 31.32, 41.62, 51.92, 62.12, 72.32, 82.52, 92.63,102.56},{ -0.17,  8.50, 19.27, 29.77, 40.07, 50.37, 60.57, 70.77, 80.97, 91.13,101.23},{ -1.80,  6.96, 17.77, 28.29, 38.61, 48.91, 59.13, 69.33, 79.53, 89.71, 99.86},{ -3.42,  5.49, 16.36, 26.94, 37.31, 47.61, 57.88, 68.08, 78.28, 88.41, 98.39},{ -4.73,  4.38, 15.34, 25.99, 36.39, 46.71, 57.01, 67.21, 77.41, 87.51, 97.41},{ -5.73,  3.63, 14.74, 25.48, 35.88, 46.26, 56.56, 66.76, 76.96, 87.06, 96.96},{ -6.24,  3.33, 14.59, 25.39, 35.84, 46.22, 56.52, 66.72, 76.92, 87.04, 97.00},{ -6.09,  3.62, 15.03, 25.83, 36.37, 46.70, 57.00, 67.20, 77.40, 87.57, 97.68},{ -5.32,  4.44, 15.90, 26.70, 37.28, 47.60, 57.90, 68.10, 78.30, 88.52, 98.78},{ -3.49,  6.17, 17.52, 28.32, 38.85, 49.22, 59.52, 69.72, 79.92, 90.20,100.61},{ -0.81,  8.58, 19.73, 30.44, 40.90, 51.24, 61.52, 71.69, 81.87, 92.15,102.63},{  2.91, 11.82, 22.64, 33.17, 43.53, 53.73, 63.96, 74.09, 84.22, 94.45,104.89},{  6.68, 15.19, 25.71, 36.03, 46.25, 56.31, 66.45, 76.49, 86.54, 96.72,107.15},{ 10.43, 18.65, 28.94, 39.02, 49.01, 58.98, 68.93, 78.78, 88.69, 98.83,109.36},{ 13.56, 21.65, 31.78, 41.68, 51.45, 61.31, 71.07, 80.73, 90.48,100.51,111.01},{ 14.36, 22.91, 33.19, 43.09, 52.71, 62.37, 71.92, 81.38, 90.88,100.56,110.56},{ 15.06, 23.90, 34.23, 44.05, 53.48, 62.90, 72.21, 81.43, 90.65, 99.93,109.34},{ 15.36, 23.90, 33.89, 43.31, 52.40, 61.42, 70.29, 79.18, 88.00, 96.69,105.17},{ 15.60, 23.90, 33.60, 42.70, 51.50, 60.20, 68.70, 77.30, 85.80, 94.00,101.70},{ 15.60, 23.90, 33.60, 42.70, 51.50, 60.20, 68.70, 77.30, 85.80, 94.00,101.70},{ 15.60, 23.90, 33.60, 42.70, 51.50, 60.20, 68.70, 77.30, 85.80, 94.00,101.70},{ 15.60, 23.90, 33.60, 42.70, 51.50, 60.20, 68.70, 77.30, 85.80, 94.00,101.70},{ 15.60, 23.90, 33.60, 42.70, 51.50, 60.20, 68.70, 77.30, 85.80, 94.00,101.70},{ 15.60, 23.90, 33.60, 42.70, 51.50, 60.20, 68.70, 77.30, 85.80, 94.00,101.70}};
double phons[11]={2,10,20,30,40,50,60,70,80,90,100};


//other functions
static void Loudness_dofft(Loudness *, uint32);

void Loudness_Ctor(Loudness* unit)
{
	//may want to check sampling rate here!

	unit->m_numbands= 42;

	unit->m_ERBbands = (float*)RTAlloc(unit->mWorld, unit->m_numbands * sizeof(float));

	Clear(unit->m_numbands, unit->m_ERBbands);

	unit->m_sones=0;
	//unit->m_phontotal=0;

	unit->mCalcFunc = (UnitCalcFunc)&Loudness_next;
	Loudness_next(unit, 1);
}

void Loudness_Dtor(Loudness *unit)
{
	RTFree(unit->mWorld, unit->m_ERBbands);
}

void Loudness_next(Loudness *unit, int wrongNumSamples)
{
	float fbufnum = ZIN0(0);

	//next FFT bufffer ready, update
	//assuming at this point that buffer precalculated for any resampling
	if (fbufnum > -0.01f)
		Loudness_dofft(unit, (uint32)fbufnum);

	//always output sones
	//float outval= unit->m_sones;

	//printf("sones %f phontotal %f \n",outval, unit->m_phontotal);

	//control rate output
	ZOUT0(0)=unit->m_sones;
}

//temporal masking over ERB bands: peaks take a while to decay
//spectral masking over which bins summed as contributors for ERB bands; spreading activation function actually implies that the overall power is greater from spread?
//masking not triangular but slanted towards masking higher frequency content (ie, lower freq bins mask upper)

//for true MP3 style compression would have to see if each FFT bin was noise like or sine like (transient measure on instantaneous frequency for example), and use the appropriate masking curve
//efficiency is preferred here

//thus can calculate squared powers as you go? cheapest if only have effect of spectral masking above, covering a fixed number of bins? but then, frequency biased loudness based on ERB band centre frequency!

//calculation function once FFT data ready
void Loudness_dofft(Loudness *unit, uint32 ibufnum)
{
	World *world = unit->mWorld;
	//if (ibufnum >= world->mNumSndBufs) ibufnum = 0;
	SndBuf *buf; // = world->mSndBufs + ibufnum;
	//int numbins = buf->samples - 2 >> 1;
	//support LocalBuf

	if (ibufnum >= world->mNumSndBufs) {
		int localBufNum = ibufnum - world->mNumSndBufs;
		Graph *parent = unit->mParent;
		if(localBufNum <= parent->localBufNum) {
			buf = parent->mLocalSndBufs + localBufNum;
		} else {
			buf = world->mSndBufs;
		}
	} else {
		buf = world->mSndBufs + ibufnum;
	}
	LOCK_SNDBUF(buf);

	float * data= buf->data;

	float loudsum=0.0;

	float smask= ZIN0(1);
	float tmask= ZIN0(2);

	for (int k=0; k<unit->m_numbands; ++k){

		int bandstart=eqlbandbins[k];
		//int bandend=eqlbandbins[k+1];
		int bandsize= eqlbandsizes[k];
		int bandend= bandstart+bandsize;

		float bsum=0.0;
		float real, imag, power;
		int index;
		float lastpower=0.0;

		for (int h=bandstart; h<bandend;++h) {
			index = 2*h;
			real= data[index];
			imag= data[index+1];

			power = (real*real) + (imag*imag);


			//would involve spectral masking here
			power = sc_max(lastpower*smask,power); //sideways spectral masking with leaky integration
			lastpower= power;

			//psychophysical sensation; within critical band, sum using a p metric, (sum m^p)^(1/p)
			//compresses the gain

			//power of three combination
			//bsum= bsum+(power*power*power);

			//won't sum up power very well
			//if(power>bsum) bsum=power;

			bsum= bsum+power;

		}

		//store recips of bandsizes?
		//why average? surely just take max or sum is better!
		//bsum= bsum/bandsize;

		//into dB, avoid log of 0
		//float db= 10*log10((bsum*10000000)+0.001);
		//float db= 10*log10((bsum*32382)+0.001);
		//empricially derived 32382*2.348

		float db= 10*log10((bsum*76032.936f)+0.001f); //correct multipler until you get loudness output of 1!

		//correcting for power of three combination
		//bsum=bsum+0.001;
		//4.8810017610244 = log10(76032.936)
		//float db= 10*((0.33334*log10(bsum)) + 4.8810017610244); //correct multipler until you get loudness output of 1!


		//printf("bsum %f db %f \n",bsum,db);

		//convert via contour
		if(db<contours[k][0]) db=0;
		else if (db>contours[k][10]) db=phons[10];
		else {

			float prop=0.0;
			int j;
			for (j=1; j<11; ++j) {
				if(db<contours[k][j]) {
					prop= (db-contours[k][j-1])/(contours[k][j]-contours[k][j-1]);
					break;
				}

				if ( j == 10 ) {
					prop=1.0;
					break; // avoid j becoming 11 to avoid out-of-bounds access in db calculation
				}
			}
			
			
			db= (1.f-prop)*phons[j-1]+ prop*phons[j];
			//printf("prop %f db %f j %d\n",prop,db,j);
		}

		//spectralmasking, 6dB drop per frame?
		//try also with just take db
		unit->m_ERBbands[k] = sc_max(db, (unit->m_ERBbands[k]) - tmask);

		//printf("db %f erbband %f \n",db, unit->m_ERBbands[k]);

		//must sum as intensities, not dbs once corrected, pow used to be other way around
		//loudsum+= ((pow(10, 0.1*unit->m_ERBbands[k])-0.001)*0.0000308813538386); //

		loudsum+= ((pow(10, 0.1*unit->m_ERBbands[k])-0.001)); //multiplier not needed since invert below; can trust no overflow?
	}

	//total excitation, correct back to dB scale in phons
	//float phontotal= 10*log10((loudsum*32382)+0.001);
	float phontotal= 10*log10((loudsum)+0.001); //didn't use divisor above, so no need to restore here

	//unit->m_phontotal= phontotal;
	//now to sones:
	/* from Praat: Excitation.c  Sones = 2 ** ((Phones - 40) / 10)  */
	unit->m_sones= pow (2.f, (phontotal - 40) / 10);

	//printf("phontotal %f sones %f \n",phontotal, unit->m_sones);

	//about 5 times per second
	//if((unit->m_triggerid) && ((unit->m_frame%2==0))) SendTrigger(&unit->mParent->mNode, unit->m_triggerid, bestkey);
}
