g729ev_g729b_qsidgain.c

最新的ITU-T的宽带语音编解码标准G.729.1,是对原先的G.729的最好的调整.码流输出速率可以进行自适应调整.满足未来通信要求.希望对大家有所帮助.

/* ITU-T G.729EV Optimization/Characterization Candidate                         */
/* Version:       1.0.a                                                          */
/* Revision Date: June 28, 2006                                                  */

/*
   ITU-T G.729EV Optimization/Characterization Candidate    ANSI-C Source Code
   Copyright (c) 2006 
   France Telecom, Matsushita Electric, Mindspeed, Siemens AG, ETRI, VoiceAge Corp.
   All rights reserved
*/

/* Quantize SID gain                                      */

#include "G729EV_G729B_dtx.h"
#include "G729EV_G729B_tab_dtx.h"

#include "G729EV_MAIN_OPER_32B.h"
#include "G729EV_MAIN_DSPFUNC.h"

/* Local function */
static Word16 Quant_Energy(Word32 L_x,    /* (i)  : Energy                 */
                           Word16 sh,     /* (i)  : Exponent of the energy */
                           Word16 * enerq /* (o)  : quantized energy in dB */
    );

/*-------------------------------------------------------------------*
 * Function  Qua_Sidgain                                             *
 *           ~~~~~~~~~~~                                             *
 *-------------------------------------------------------------------*/
void Qua_Sidgain(Word16 * ener,     /* (i)   array of energies                   */
                 Word16 * sh_ener,  /* (i)   corresponding scaling factors       */
                 Word16 nb_ener,    /* (i)   number of energies or               */
                 Word16 * enerq,    /* (o)   decoded energies in dB              */
                 Word16 * idx       /* (o)   SID gain quantization index         */
    )
{
  Word32    L_acc;

  Word16    i;
  Word32    L_x;
  Word16    sh1, temp;
  Word16    hi, lo;

  IF(nb_ener == 0)
  {
    /* Quantize energy saved for frame erasure case                */
    /* L_x = average_ener                                          */
    L_acc = L_deposit_l(*ener);
    L_acc = L_shl(L_acc, *sh_ener); /* >> if *sh_ener < 0 */
    L_Extract(L_acc, &hi, &lo);
    L_x = Mpy_32_16(hi, lo, fact[0]);
    sh1 = (Word16) 0;
#if(WMOPS)
    move16();
#endif
  }
  ELSE
  {

    /*
     * Compute weighted average of energies
     * ener[i] = enerR[i] x 2**sh_ener[i]
     * L_x = k[nb_ener] x SUM(i=0->nb_ener-1) enerR[i]
     * with k[nb_ener] =  fact_ener / nb_ener x L_FRAME x nbAcf
     */
    sh1 = sh_ener[0];
#if(WMOPS)
    move16();
#endif
    FOR(i = 1; i < nb_ener; i++)
    {
      if (sh_ener[i] < sh1)
      {
        sh1 = sh_ener[i];
#if(WMOPS)
        move16();
#endif
      }
    }
    sh1 = add(sh1, (Word16) (16 - marg[nb_ener]));
    L_x = (Word32) 0L;
#if(WMOPS)
    move32();
#endif
    FOR(i = 0; i < nb_ener; i++)
    {
      temp = sub(sh1, sh_ener[i]);
      L_acc = L_deposit_l(ener[i]);
      L_acc = L_shl(L_acc, temp);
      L_x = L_add(L_x, L_acc);
    }
    L_Extract(L_x, &hi, &lo);
    L_x = Mpy_32_16(hi, lo, fact[i]);
  }

  *idx = Quant_Energy(L_x, sh1, enerq);

  return;
}


/* Local function */

static Word16 Quant_Energy(Word32 L_x,     /* (i)  : Energy                 */
                           Word16 sh,      /* (i)  : Exponent of the energy */
                           Word16 * enerq  /* (o)  : quantized energy in dB */
    )
{

  Word16    exp, frac;
  Word16    e_tmp, temp, index;

  Log2(L_x, &exp, &frac);
  temp = sub(exp, sh);
  e_tmp = shl(temp, 10);
  e_tmp = add(e_tmp, mult_r(frac, 1024)); /* 2^10 x log2(L_x . 2^-sh) */
  /* log2(ener) = 10log10(ener) / K */
  /* K = 10 Log2 / Log10 */

  temp = sub(e_tmp, -2721);     /* -2721 -> -8dB */
  IF(temp <= 0)
  {
    *enerq = (Word16) - 12;
#if(WMOPS)
    move16();
#endif
    return (0);
  }

  temp = sub(e_tmp, 22111);     /* 22111 -> 65 dB */
  IF(temp > 0)
  {
    *enerq = (Word16) 66;
#if(WMOPS)
    move16();
#endif
    return (31);
  }

  temp = sub(e_tmp, 4762);      /* 4762 -> 14 dB */
  IF(temp <= 0)
  {
    e_tmp = add(e_tmp, 3401);
    index = mult(e_tmp, 24);
    if (sub(index, 1) < 0)
    {
      index = (Word16) 1;
#if(WMOPS)
      move16();
#endif
    }
    *enerq = sub(shl(index, 2), 8);
    return (index);
  }

  e_tmp = sub(e_tmp, 340);
  index = sub(shr(mult(e_tmp, 193), 2), 1);
  if (sub(index, 6) < 0)
  {
    index = (Word16) 6;
#if(WMOPS)
    move16();
#endif
  }
  *enerq = add(shl(index, 1), 4);
  return (index);
}