libSBRenc/src/sbrenc_freq_sca.cpp

/* -----------------------------------------------------------------------------------------------------------
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Attention: Audio and Multimedia Departments - FDK AAC LL
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----------------------------------------------------------------------------------------------------------- */

/*!
  \file
  \brief  frequency scale  
*/

#include "sbrenc_freq_sca.h"
#include "sbr_misc.h"

#include "genericStds.h"

/*  StartFreq */
static INT getStartFreq(INT fs, const INT start_freq);

/* StopFreq */
static INT getStopFreq(INT fs, const INT stop_freq, const INT noChannels);

static INT  numberOfBands(INT b_p_o, INT start, INT stop, FIXP_DBL warp_factor);
static void CalcBands(INT * diff, INT start , INT stop , INT num_bands);
static INT  modifyBands(INT max_band, INT * diff, INT length);
static void cumSum(INT start_value, INT* diff, INT length, UCHAR  *start_adress);



/*******************************************************************************
 Functionname:  FDKsbrEnc_getSbrStartFreqRAW
 *******************************************************************************
 Description:

 Arguments:

 Return:
 *******************************************************************************/

INT
FDKsbrEnc_getSbrStartFreqRAW (INT startFreq, INT QMFbands, INT fs)
{
  INT result;

  if ( startFreq < 0 || startFreq > 15) {
    return -1;
  }
  /* Update startFreq struct */
  result = getStartFreq(fs, startFreq);

  result = (result*fs/QMFbands+1)>>1;

  return (result);

} /* End FDKsbrEnc_getSbrStartFreqRAW */


/*******************************************************************************
 Functionname:  getSbrStopFreq
 *******************************************************************************
 Description:

 Arguments:

 Return:
 *******************************************************************************/
INT FDKsbrEnc_getSbrStopFreqRAW  (INT stopFreq, INT QMFbands, INT fs)
{
  INT result;

  if ( stopFreq < 0 || stopFreq > 13)
    return -1;


  /* Uppdate stopFreq struct */
  result = getStopFreq( fs, stopFreq, QMFbands);
  result =   (result*fs/QMFbands+1)>>1;

  return (result);
} /* End getSbrStopFreq */


/*******************************************************************************
 Functionname:  getStartFreq
 *******************************************************************************
 Description:

 Arguments:

 Return:
 *******************************************************************************/
static INT
getStartFreq(INT fs, const INT start_freq)
{
  INT k0_min;

  switch(fs){
  case 16000: k0_min = 24;
    break;
  case 22050: k0_min = 17;
    break;
  case 24000: k0_min = 16;
    break;
  case 32000: k0_min = 16;
    break;
  case 44100: k0_min = 12;
    break;
  case 48000: k0_min = 11;
    break;
  case 64000: k0_min = 10;
    break;
  case 88200: k0_min = 7;
    break;
  case 96000: k0_min = 7;
    break;
  default:
    k0_min=11; /* illegal fs */
  }


  switch (fs) {

  case 16000:
    {
      INT v_offset[]= {-8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7};
      return (k0_min + v_offset[start_freq]);
    }
  case 22050:
    {
      INT v_offset[]= {-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13};
      return (k0_min + v_offset[start_freq]);
    }
  case 24000:
    {
      INT v_offset[]= {-5, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16};
      return (k0_min + v_offset[start_freq]);
    }
  case 32000:
    {
      INT v_offset[]= {-6, -4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16};
      return (k0_min + v_offset[start_freq]);
    }
  case 44100:
  case 48000:
  case 64000:
    {
      INT v_offset[]= {-4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20};
      return (k0_min + v_offset[start_freq]);
    }
  case 88200:
  case 96000:
    {
      INT v_offset[]= {-2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20, 24};
      return (k0_min + v_offset[start_freq]);
    }
  default:
    {
      INT v_offset[]= {0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20, 24, 28, 33};
      return (k0_min + v_offset[start_freq]);
    }
  }
} /* End getStartFreq */


/*******************************************************************************
 Functionname:  getStopFreq
 *******************************************************************************
 Description:

 Arguments:

 Return:
 *******************************************************************************/
 static INT
getStopFreq(INT fs, const INT stop_freq, const INT noChannels)
{
  INT result,i;
  INT k1_min;
  INT v_dstop[13];


  INT *v_stop_freq = NULL;
  INT v_stop_freq_16[14] = {48,49,50,51,52,54,55,56,57,59,60,61,63,64};
  INT v_stop_freq_22[14] = {35,37,38,40,42,44,46,48,51,53,56,58,61,64};
  INT v_stop_freq_24[14] = {32,34,36,38,40,42,44,46,49,52,55,58,61,64};
  INT v_stop_freq_32[14] = {32,34,36,38,40,42,44,46,49,52,55,58,61,64};
  INT v_stop_freq_44[14] = {23,25,27,29,32,34,37,40,43,47,51,55,59,64};
  INT v_stop_freq_48[14] = {21,23,25,27,30,32,35,38,42,45,49,54,59,64};
  INT v_stop_freq_64[14] = {20,22,24,26,29,31,34,37,41,45,49,54,59,64};
  INT v_stop_freq_88[14] = {15,17,19,21,23,26,29,33,37,41,46,51,57,64};
  INT v_stop_freq_96[14] = {13,15,17,19,21,24,27,31,35,39,44,50,57,64};

  switch(fs){
  case 16000: k1_min = 48;
              v_stop_freq =v_stop_freq_16;
    break;
  case 22050: k1_min = 35;
              v_stop_freq =v_stop_freq_22;
    break;
  case 24000: k1_min = 32;
              v_stop_freq =v_stop_freq_24;
    break;
  case 32000: k1_min = 32;
              v_stop_freq =v_stop_freq_32;
    break;
  case 44100: k1_min = 23;
              v_stop_freq =v_stop_freq_44;
    break;
  case 48000: k1_min = 21;
              v_stop_freq =v_stop_freq_48;
    break;
  case 64000: k1_min = 20;
              v_stop_freq =v_stop_freq_64;
    break;
  case 88200: k1_min = 15;
              v_stop_freq =v_stop_freq_88;
    break;
  case 96000: k1_min = 13;
              v_stop_freq =v_stop_freq_96;
    break;
  default:
    k1_min = 21; /* illegal fs  */
  }


  /* Ensure increasing bandwidth */
  for(i = 0; i <= 12; i++) {
    v_dstop[i] = v_stop_freq[i+1] - v_stop_freq[i];
  }

  FDKsbrEnc_Shellsort_int(v_dstop, 13); /* Sort bandwidth changes */

  result = k1_min;
  for(i = 0; i < stop_freq; i++) {
    result = result + v_dstop[i];
  }

  return(result);

}/* End getStopFreq */


/*******************************************************************************
 Functionname:  FDKsbrEnc_FindStartAndStopBand
 *******************************************************************************
 Description:

 Arguments:

 Return:
 *******************************************************************************/
INT
FDKsbrEnc_FindStartAndStopBand(const INT samplingFreq,
                     const INT noChannels,
                     const INT startFreq,
                     const INT stopFreq,
                     const SR_MODE sampleRateMode,
                     INT *k0,
                     INT *k2)
{

  /* Update startFreq struct */
  *k0 = getStartFreq(samplingFreq, startFreq);

  /* Test if start freq is outside corecoder range */
  if( ( sampleRateMode == 1 ) &&
      ( samplingFreq*noChannels  <
        2**k0 * samplingFreq) ) {
    return (1); /* raise the cross-over frequency and/or lower the number
                   of target bands per octave (or lower the sampling frequency) */
  }

  /*Update stopFreq struct */
  if ( stopFreq < 14 ) {
    *k2 = getStopFreq(samplingFreq, stopFreq, noChannels);
  } else if( stopFreq == 14 ) {
    *k2 = 2 * *k0;
  } else {
    *k2 = 3 * *k0;
  }

  /* limit to Nyqvist */
  if (*k2 > noChannels) {
    *k2 = noChannels;
  }



  /* Test for invalid  k0 k2 combinations */
  if ( (samplingFreq == 44100) && ( (*k2 - *k0) > MAX_FREQ_COEFFS_FS44100 ) )
    return (1); /* Number of bands exceeds valid range of MAX_FREQ_COEFFS for fs=44.1kHz */

  if ( (samplingFreq >= 48000) && ( (*k2 - *k0) > MAX_FREQ_COEFFS_FS48000 ) )
    return (1); /* Number of bands exceeds valid range of MAX_FREQ_COEFFS for fs>=48kHz */

  if ((*k2 - *k0) > MAX_FREQ_COEFFS)
    return (1);/*Number of bands exceeds valid range of MAX_FREQ_COEFFS */

  if ((*k2 - *k0) < 0)
    return (1);/* Number of bands is negative */


  return(0);
}

/*******************************************************************************
 Functionname:  FDKsbrEnc_UpdateFreqScale
 *******************************************************************************
 Description:

 Arguments:

 Return:
 *******************************************************************************/
INT
FDKsbrEnc_UpdateFreqScale(UCHAR  *v_k_master, INT *h_num_bands,
                const INT k0, const INT k2,
                const INT freqScale,
                const INT alterScale)

{

  INT     b_p_o = 0;        /* bands_per_octave */
  FIXP_DBL   warp = FL2FXCONST_DBL(0.0f);
  INT     dk = 0;

  /* Internal variables */
  INT     k1 = 0, i;
  INT     num_bands0;
  INT     num_bands1;
  INT     diff_tot[MAX_OCTAVE + MAX_SECOND_REGION];
  INT     *diff0 = diff_tot;
  INT     *diff1 = diff_tot+MAX_OCTAVE;
  INT     k2_achived;
  INT     k2_diff;
  INT     incr = 0;

  /* Init */
  if (freqScale==1)  b_p_o = 12;
  if (freqScale==2)  b_p_o = 10;
  if (freqScale==3)  b_p_o = 8;


  if(freqScale > 0) /*Bark*/
    {
      if(alterScale==0)
        warp = FL2FXCONST_DBL(0.5f);        /* 1.0/(1.0*2.0) */
      else
        warp = FL2FXCONST_DBL(1.0f/2.6f);   /* 1.0/(1.3*2.0); */


      if(4*k2 >= 9*k0)  /*two or more regions*/
        {
          k1=2*k0;

          num_bands0=numberOfBands(b_p_o, k0, k1, FL2FXCONST_DBL(0.5f));
          num_bands1=numberOfBands(b_p_o, k1, k2, warp);

          CalcBands(diff0, k0, k1, num_bands0);/*CalcBands1 => diff0 */
          FDKsbrEnc_Shellsort_int( diff0, num_bands0);/*SortBands sort diff0 */

          if (diff0[0] == 0) /* too wide FB bands for target tuning */
          {
            return (1);/* raise the cross-over frequency and/or lower the number
                          of target bands per octave (or lower the sampling frequency */
          }

          cumSum(k0, diff0, num_bands0, v_k_master); /* cumsum */

          CalcBands(diff1, k1, k2, num_bands1);     /* CalcBands2 => diff1 */
          FDKsbrEnc_Shellsort_int( diff1, num_bands1);            /* SortBands sort diff1 */
          if(diff0[num_bands0-1] > diff1[0])        /* max(1) > min(2) */
            {
              if(modifyBands(diff0[num_bands0-1],diff1, num_bands1))
                return(1);
            }

          /* Add 2'nd region */
          cumSum(k1, diff1, num_bands1, &v_k_master[num_bands0]);
          *h_num_bands=num_bands0+num_bands1;     /* Output nr of bands */

        }
      else /* one region */
        {
          k1=k2;

          num_bands0=numberOfBands(b_p_o, k0, k1, FL2FXCONST_DBL(0.5f));
          CalcBands(diff0, k0, k1, num_bands0);/* CalcBands1 => diff0 */
          FDKsbrEnc_Shellsort_int( diff0, num_bands0);       /* SortBands sort diff0 */

          if (diff0[0] == 0) /* too wide FB bands for target tuning */
          {
            return (1); /* raise the cross-over frequency and/or lower the number
                           of target bands per octave (or lower the sampling frequency */
          }

          cumSum(k0, diff0, num_bands0, v_k_master);/* cumsum */
          *h_num_bands=num_bands0;        /* Output nr of bands */

        }
    }
  else /* Linear mode */
    {
      if (alterScale==0) {
        dk = 1;
        num_bands0 = 2 * ((k2 - k0)/2);         /* FLOOR to get to few number of bands*/
      } else {
        dk = 2;
        num_bands0 = 2 * (((k2 - k0)/dk +1)/2); /* ROUND to get closest fit */
      }

      k2_achived = k0 + num_bands0*dk;
      k2_diff = k2 - k2_achived;

      for(i=0;i<num_bands0;i++)
        diff_tot[i] = dk;

      /* If linear scale wasn't achived */
      /* and we got wide SBR are */
      if (k2_diff < 0) {
          incr = 1;
          i = 0;
      }

      /* If linear scale wasn't achived */
      /* and we got small SBR are */
      if (k2_diff > 0) {
          incr = -1;
          i = num_bands0-1;
      }

      /* Adjust diff vector to get sepc. SBR range */
      while (k2_diff != 0) {
        diff_tot[i] = diff_tot[i] - incr;
        i = i + incr;
        k2_diff = k2_diff + incr;
      }

      cumSum(k0, diff_tot, num_bands0, v_k_master);/* cumsum */
      *h_num_bands=num_bands0;        /* Output nr of bands */

    }

  if (*h_num_bands < 1)
    return(1); /*To small sbr area */

  return (0);
}/* End FDKsbrEnc_UpdateFreqScale */

static INT
numberOfBands(INT b_p_o, INT start, INT stop, FIXP_DBL warp_factor)
{
  INT result=0;
  /* result = 2* (INT) ( (double)b_p_o * (double)(FDKlog((double)stop/(double)start)/FDKlog((double)2)) * (double)FX_DBL2FL(warp_factor) + 0.5); */
  result = ( ( b_p_o * fMult( (CalcLdInt(stop) - CalcLdInt(start)),  warp_factor) + (FL2FX_DBL(0.5f)>>LD_DATA_SHIFT)
               ) >> ((DFRACT_BITS-1)-LD_DATA_SHIFT) ) << 1; /* do not optimize anymore (rounding!!) */

  return(result);
}


static void
CalcBands(INT * diff, INT start , INT stop , INT num_bands)
{
    INT i, qb, qe, qtmp;
    INT previous;
    INT current;
    FIXP_DBL base, exp, tmp;

    previous=start;
    for(i=1; i<= num_bands; i++)
    {
        base = fDivNorm((FIXP_DBL)stop, (FIXP_DBL)start, &qb);
        exp = fDivNorm((FIXP_DBL)i, (FIXP_DBL)num_bands, &qe);
        tmp = fPow(base, qb, exp, qe, &qtmp);
        tmp = fMult(tmp, (FIXP_DBL)(start<<24));
        current   = (INT)scaleValue(tmp, qtmp-23);
        current   = (current+1) >> 1; /* rounding*/
        diff[i-1] = current-previous;
        previous  = current;
    }

}/* End CalcBands */


static void
cumSum(INT start_value, INT* diff, INT length,  UCHAR *start_adress)
{
  INT i;
  start_adress[0]=start_value;
  for(i=1;i<=length;i++)
    start_adress[i]=start_adress[i-1]+diff[i-1];
} /* End cumSum */


static INT
modifyBands(INT max_band_previous, INT * diff, INT length)
{
  INT change=max_band_previous-diff[0];

  /* Limit the change so that the last band cannot get narrower than the first one */
  if ( change > (diff[length-1] - diff[0]) / 2 )
    change = (diff[length-1] - diff[0]) / 2;

  diff[0] += change;
  diff[length-1] -= change;
  FDKsbrEnc_Shellsort_int(diff, length);

  return(0);
}/* End modifyBands */


/*******************************************************************************
 Functionname:  FDKsbrEnc_UpdateHiRes
 *******************************************************************************
 Description:

 Arguments:

 Return:
 *******************************************************************************/
INT
FDKsbrEnc_UpdateHiRes(UCHAR *h_hires, INT *num_hires,UCHAR * v_k_master,
            INT num_master , INT *xover_band, SR_MODE drOrSr,
            INT noQMFChannels)
{
  INT i;
  INT divider;
  INT max1,max2;

  /* Check if we use a Dual rate => diver=2 else 1 */
  divider = (drOrSr == DUAL_RATE) ? 2 : 1;

  if( (v_k_master[*xover_band] > (noQMFChannels/divider) ) ||
      ( *xover_band > num_master ) )  {
      /* xover_band error, too big for this startFreq. Will be clipped */

    /* Calculate maximum value for xover_band */
    max1=0;
    max2=num_master;
    while( (v_k_master[max1+1] < (noQMFChannels/divider)) &&
           ( (max1+1) < max2) )
      {
        max1++;
      }

    *xover_band=max1;
  }

  *num_hires = num_master - *xover_band;
  for(i = *xover_band; i <= num_master; i++)
    {
      h_hires[i - *xover_band] = v_k_master[i];
    }

  return (0);
}/* End FDKsbrEnc_UpdateHiRes */


/*******************************************************************************
 Functionname:  FDKsbrEnc_UpdateLoRes
 *******************************************************************************
 Description:

 Arguments:

 Return:
 *******************************************************************************/
void
FDKsbrEnc_UpdateLoRes(UCHAR * h_lores, INT *num_lores, UCHAR * h_hires, INT num_hires)
{
  INT i;

  if(num_hires%2 == 0) /* if even number of hires bands */
    {
      *num_lores=num_hires/2;
      /* Use every second lores=hires[0,2,4...] */
      for(i=0;i<=*num_lores;i++)
        h_lores[i]=h_hires[i*2];

    }
  else            /* odd number of hires which means xover is odd */
    {
      *num_lores=(num_hires+1)/2;

      /* Use lores=hires[0,1,3,5 ...] */
      h_lores[0]=h_hires[0];
      for(i=1;i<=*num_lores;i++)
        {
          h_lores[i]=h_hires[i*2-1];
        }
    }

}/* End FDKsbrEnc_UpdateLoRes */