/* (C) 2007 Jean-Marc Valin, CSIRO
*/
/*
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   are met:
   
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   notice, this list of conditions and the following disclaimer.
   
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   notice, this list of conditions and the following disclaimer in the
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   contributors may be used to endorse or promote products derived from
   this software without specific prior written permission.
   
   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
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*/


#include "quant_bands.h"
#include "laplace.h"
#include <math.h>
#include "os_support.h"

const float eMeans[24] = {45.f, -8.f, -12.f, -2.5f, 1.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f};

//const int frac[24] = {4, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2};
const int frac[24] = {8, 6, 5, 4, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2};

static void quant_energy_mono(const CELTMode *m, float *eBands, float *oldEBands, int budget, ec_enc *enc)
{
   int i;
   int bits;
   float prev = 0;
   float coef = m->ePredCoef;
   float error[m->nbEBands];
   /* The .7 is a heuristic */
   float beta = .7*coef;
   bits = ec_enc_tell(enc, 0);
   for (i=0;i<m->nbEBands;i++)
   {
      int qi;
      float q;
      float res;
      float x;
      float f;
      float mean = (1-coef)*eMeans[i];
      x = 20*log10(.3+eBands[i]);
      res = 6.;
      //res = 1;
      f = (x-mean-coef*oldEBands[i]-prev)/res;
      qi = (int)floor(.5+f);
      //if (i> 4 && qi<-2)
      //   qi = -2;
      //ec_laplace_encode(enc, qi, i==0?11192:6192);
      //ec_laplace_encode(enc, qi, 8500-i*200);
      /* If we don't have enough bits to encode all the energy, just assume something safe. */
      if (ec_enc_tell(enc, 0) - bits > budget)
         qi = -1;
      else
         ec_laplace_encode(enc, qi, 6000-i*200);
      q = qi*res;
      error[i] = f - qi;
      
      //printf("%d ", qi);
      //printf("%f %f ", pred+prev+q, x);
      //printf("%f ", x-pred);
      
      oldEBands[i] = mean+coef*oldEBands[i]+prev+q;
      
      prev = mean+prev+(1-beta)*q;
   }
   //bits = ec_enc_tell(enc, 0) - bits;
   //printf ("%d\n", bits);
   for (i=0;i<m->nbEBands;i++)
   {
      int q2;
      float offset = (error[i]+.5)*frac[i];
      /* FIXME: Instead of giving up without warning, we should degrade everything gracefully */
      if (ec_enc_tell(enc, 0) - bits +ec_ilog(frac[i])> budget)
         break;
      q2 = (int)floor(offset);
      if (q2 > frac[i]-1)
         q2 = frac[i]-1;
      ec_enc_uint(enc, q2, frac[i]);
      offset = ((q2+.5)/frac[i])-.5;
      oldEBands[i] += 6.*offset;
      //printf ("%f ", error[i] - offset);
   }
   for (i=0;i<m->nbEBands;i++)
   {
      eBands[i] = pow(10, .05*oldEBands[i])-.3;
      if (eBands[i] < 0)
         eBands[i] = 0;
   }
   //printf ("%d\n", ec_enc_tell(enc, 0)-9);

   //printf ("\n");
}

static void unquant_energy_mono(const CELTMode *m, float *eBands, float *oldEBands, int budget, ec_dec *dec)
{
   int i;
   int bits;
   float prev = 0;
   float coef = m->ePredCoef;
   /* The .7 is a heuristic */
   float beta = .7*coef;
   bits = ec_dec_tell(dec, 0);
   for (i=0;i<m->nbEBands;i++)
   {
      int qi;
      float q;
      float res;
      float mean = (1-coef)*eMeans[i];
      res = 6.;
      /* If we didn't have enough bits to encode all the energy, just assume something safe. */
      if (ec_dec_tell(dec, 0) - bits > budget)
         qi = -1;
      else
         qi = ec_laplace_decode(dec, 6000-i*200);
      q = qi*res;
      
      oldEBands[i] = mean+coef*oldEBands[i]+prev+q;
      
      prev = mean+prev+(1-beta)*q;
   }
   for (i=0;i<m->nbEBands;i++)
   {
      int q2;
      float offset;
      if (ec_dec_tell(dec, 0) - bits +ec_ilog(frac[i])> budget)
         break;
      q2 = ec_dec_uint(dec, frac[i]);
      offset = ((q2+.5)/frac[i])-.5;
      oldEBands[i] += 6.*offset;
   }
   for (i=0;i<m->nbEBands;i++)
   {
      //printf ("%f ", error[i] - offset);
      eBands[i] = pow(10, .05*oldEBands[i])-.3;
      if (eBands[i] < 0)
         eBands[i] = 0;
   }
   //printf ("\n");
}



void quant_energy(const CELTMode *m, float *eBands, float *oldEBands, int budget, ec_enc *enc)
{
   int C;
   
   C = m->nbChannels;

   if (C==1)
      quant_energy_mono(m, eBands, oldEBands, budget, enc);
   else 
#if 1
   {
      int c;
      for (c=0;c<C;c++)
      {
         int i;
         float E[m->nbEBands];
         for (i=0;i<m->nbEBands;i++)
            E[i] = eBands[C*i+c];
         quant_energy_mono(m, E, oldEBands+c*m->nbEBands, budget/C, enc);
         for (i=0;i<m->nbEBands;i++)
            eBands[C*i+c] = E[i];
      }
   }
#else
      if (C==2)
   {
      int i;
      int NB = m->nbEBands;
      float mid[NB];
      float side[NB];
      float left;
      float right;
      for (i=0;i<NB;i++)
      {
         //left = eBands[C*i];
         //right = eBands[C*i+1];
         mid[i] = sqrt(eBands[C*i]*eBands[C*i] + eBands[C*i+1]*eBands[C*i+1]);
         side[i] = 20*log10((eBands[2*i]+.3)/(eBands[2*i+1]+.3));
         //printf ("%f %f ", mid[i], side[i]);
      }
      //printf ("\n");
      quant_energy_mono(m, mid, oldEBands, enc);
      for (i=0;i<NB;i++)
         side[i] = pow(10.f,floor(.5f+side[i])/10.f);
         
      //quant_energy_side(m, side, oldEBands+NB, enc);
      for (i=0;i<NB;i++)
      {
         eBands[C*i] = mid[i]*sqrt(side[i]/(1.f+side[i]));
         eBands[C*i+1] = mid[i]*sqrt(1.f/(1.f+side[i]));
         //printf ("%f %f ", mid[i], side[i]);
      }

   } else {
      celt_fatal("more than 2 channels not supported");
   }
#endif
}



void unquant_energy(const CELTMode *m, float *eBands, float *oldEBands, int budget, ec_dec *dec)
{
   int C;   
   C = m->nbChannels;

   if (C==1)
      unquant_energy_mono(m, eBands, oldEBands, budget, dec);
   else {
      int c;
      for (c=0;c<C;c++)
      {
         int i;
         float E[m->nbEBands];
         unquant_energy_mono(m, E, oldEBands+c*m->nbEBands, budget/C, dec);
         for (i=0;i<m->nbEBands;i++)
            eBands[C*i+c] = E[i];
      }
   }
}