sbrenc_freq_sca.cpp - Android社区 - https://www.androidos.net.cn/

/* -----------------------------------------------------------------------------------------------------------
Software License for The Fraunhofer FDK AAC Codec Library for Android

1.    INTRODUCTION
The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
This FDK AAC Codec software is intended to be used on a wide variety of Android devices.

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of the MPEG specifications.

Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
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Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
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Redistribution and use in source and binary forms, with or without modification, are permitted without
payment of copyright license fees provided that you satisfy the following conditions:

You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
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5.    CONTACT INFORMATION

Fraunhofer Institute for Integrated Circuits IIS
Attention: Audio and Multimedia Departments - FDK AAC LL
Am Wolfsmantel 33
91058 Erlangen, Germany

www.iis.fraunhofer.de/amm
amm-info@iis.fraunhofer.de
----------------------------------------------------------------------------------------------------------- */

/*!
  \file
  \brief  frequency scale  
  \author Tobias Chalupka
*/

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

#include "genericStds.h"

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

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

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 fsCore)
{
  INT result;

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

result = (result*(fsCore>>5)+1)>>1; /* (result*fsSBR/QMFbands+1)>>1; */

return (result);

} /* End FDKsbrEnc_getSbrStartFreqRAW */

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

Arguments:

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

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

/* Uppdate stopFreq struct */
  result = getStopFreq(fsCore, stopFreq);
  result = (result*(fsCore>>5)+1)>>1; /* (result*fsSBR/QMFbands+1)>>1; */

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

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

Arguments:  fsCore - core sampling rate

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

switch(fsCore){
  case  8000: k0_min = 24; /* (3000 * nQmfChannels / fsSBR ) + 0.5 */
    break;
  case 11025: k0_min = 17; /* (3000 * nQmfChannels / fsSBR ) + 0.5 */
    break;
  case 12000: k0_min = 16; /* (3000 * nQmfChannels / fsSBR ) + 0.5 */
    break;
  case 16000: k0_min = 16; /* (4000 * nQmfChannels / fsSBR ) + 0.5 */
    break;
  case 22050: k0_min = 12; /* (4000 * nQmfChannels / fsSBR ) + 0.5 */
    break;
  case 24000: k0_min = 11; /* (4000 * nQmfChannels / fsSBR ) + 0.5 */
    break;
  case 32000: k0_min = 10; /* (5000 * nQmfChannels / fsSBR ) + 0.5 */
    break;
  case 44100: k0_min = 7;  /* (5000 * nQmfChannels / fsSBR ) + 0.5 */
    break;
  case 48000: k0_min = 7;  /* (5000 * nQmfChannels / fsSBR ) + 0.5 */
    break;
  case 96000: k0_min = 3;  /* (5000 * nQmfChannels / fsSBR ) + 0.5 */
    break;
  default:
    k0_min=11; /* illegal fs */
  }

switch (fsCore) {

case  8000:
    {
      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 11025:
    {
      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 12000:
    {
      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 16000:
    {
      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 22050:
  case 24000:
  case 32000:
    {
      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 44100:
  case 48000:
  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 fsCore, const INT stop_freq)
{
  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};
  INT v_stop_freq_192[14] = {7, 8,10,12,14,16,19,23,27,32,38,46,54,64};

switch(fsCore){
  case  8000: k1_min = 48;
              v_stop_freq =v_stop_freq_16;
    break;
  case 11025: k1_min = 35;
              v_stop_freq =v_stop_freq_22;
    break;
  case 12000: k1_min = 32;
              v_stop_freq =v_stop_freq_24;
    break;
  case 16000: k1_min = 32;
              v_stop_freq =v_stop_freq_32;
    break;
  case 22050: k1_min = 23;
              v_stop_freq =v_stop_freq_44;
    break;
  case 24000: k1_min = 21;
              v_stop_freq =v_stop_freq_48;
    break;
  case 32000: k1_min = 20;
              v_stop_freq =v_stop_freq_64;
    break;
  case 44100: k1_min = 15;
              v_stop_freq =v_stop_freq_88;
    break;
  case 48000: k1_min = 13;
              v_stop_freq =v_stop_freq_96;
    break;
  case 96000: k1_min =  7;
              v_stop_freq =v_stop_freq_192;
    break;
  default:
    k1_min = 21; /* illegal fs  */
  }

/* if no valid core samplingrate is used this loop produces
     a segfault, because v_stop_freq is not initialized */
  /* 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:     srSbr            SBR sampling freqency
                srCore           AAC core sampling freqency
                noChannels       Number of QMF channels
                startFreq        SBR start frequency in QMF bands
                stopFreq         SBR start frequency in QMF bands

*k0               Output parameter
               *k2               Output parameter

Return:       Error code (0 is OK)
 *******************************************************************************/
INT
FDKsbrEnc_FindStartAndStopBand(
        const INT srSbr,
        const INT srCore,
        const INT noChannels,
        const INT startFreq,
        const INT stopFreq,
        INT *k0,
        INT *k2
        )
{

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

/* Test if start freq is outside corecoder range */
  if( srSbr*noChannels < *k0 * srCore ) {
    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(srCore, stopFreq);
  } 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 ( (srCore == 22050) && ( (*k2 - *k0) > MAX_FREQ_COEFFS_FS44100 ) )
    return (1); /* Number of bands exceeds valid range of MAX_FREQ_COEFFS for fs=44.1kHz */

if ( (srCore >= 24000) && ( (*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 (how many times the basis band is copied)*/
        {
          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
        )
{
  INT i;
  INT max1,max2;

if( (v_k_master[*xover_band] > 32 ) || /* v_k_master[*xover_band] > noQMFChannels(dualRate)/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] < 32 ) && /* noQMFChannels(dualRate)/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 */

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