
   /******************************************************************

       iLBC Speech Coder ANSI-C Source Code

       iCBConstruct.c

       Copyright (C) The Internet Society (2004).
       All Rights Reserved.

   ******************************************************************/

#include <math.h>

#include "iLBC_define.h"
#include "gainquant.h"
#include "getCBvec.h"

   /*----------------------------------------------------------------*
    *  Convert the codebook indexes to make the search easier
    *---------------------------------------------------------------*/






void index_conv_enc(int *index  /* (i/o) Codebook indexes */
  )
{
  int k;

  for (k = 1; k < CB_NSTAGES; k++) {

    if ((index[k] >= 108) && (index[k] < 172)) {
      index[k] -= 64;
    } else if (index[k] >= 236) {
      index[k] -= 128;
    } else {
      /* ERROR */
    }
  }
}

void index_conv_dec(int *index  /* (i/o) Codebook indexes */
  )
{
  int k;

  for (k = 1; k < CB_NSTAGES; k++) {

    if ((index[k] >= 44) && (index[k] < 108)) {
      index[k] += 64;
    } else if ((index[k] >= 108) && (index[k] < 128)) {
      index[k] += 128;
    } else {
      /* ERROR */
    }
  }
}

   /*----------------------------------------------------------------*
    *  Construct decoded vector from codebook and gains.
    *---------------------------------------------------------------*/

void iCBConstruct(float *decvector,     /* (o) Decoded vector */
  int *index,                   /* (i) Codebook indices */
  int *gain_index,              /* (i) Gain quantization indices */
  float *mem,                   /* (i) Buffer for codevector construction */
  int lMem,                     /* (i) Length of buffer */
  int veclen,                   /* (i) Length of vector */
  int nStages                   /* (i) Number of codebook stages */
  )
{
  int j, k;





  float gain[CB_NSTAGES];
  float cbvec[SUBL];

  /* gain de-quantization */

  gain[0] = gaindequant(gain_index[0], 1.0, 32);
  if (nStages > 1) {
    gain[1] = gaindequant(gain_index[1], (float) fabs(gain[0]), 16);
  }
  if (nStages > 2) {
    gain[2] = gaindequant(gain_index[2], (float) fabs(gain[1]), 8);
  }

  /* codebook vector construction and construction of
     total vector */

  getCBvec(cbvec, mem, index[0], lMem, veclen);
  for (j = 0; j < veclen; j++) {
    decvector[j] = gain[0] * cbvec[j];
  }
  if (nStages > 1) {
    for (k = 1; k < nStages; k++) {
      getCBvec(cbvec, mem, index[k], lMem, veclen);
      for (j = 0; j < veclen; j++) {
        decvector[j] += gain[k] * cbvec[j];
      }
    }
  }
}
