g729ev_g729b_calcexc.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
*/

#include "stl.h"
#include "G729EV_MAIN_OPER_32B.h"
#include "G729EV_MAIN_DSPFUNC.h"
#include "G729EV_G729_defines.h"
#include "G729EV_G729_ld8k.h"

#include "G729EV_G729B_defines.h"

/* Local functions */
static Word16 Gauss(Word16 * seed);
static Word16 Sqrt(Word32 Num);

/*-----------------------------------------------------------*
 * procedure Calc_exc_rand                                   *
 *           ~~~~~~~~~~~~~                                   *
 *   Computes comfort noise excitation                       *
 *   for SID and not-transmitted frames                      *
 *-----------------------------------------------------------*/
void Calc_exc_rand(G729EV_G729_DECSTAT * pDecStat, Word16 cur_gain, /* (i)   :   target sample gain                 */
                   Word16 * exc,  /* (i/o) :   excitation array                   */
                   Word16 * seed, /* (i)   :   current Vad decision               */
                   Flag flag_cod  /* (i)   :   encoder/decoder flag               */
    )
{
  Word16    i, j, i_subfr;
  Word16    temp1, temp2, tmp16;
  Word16    pos[4];
  Word16    sign[4];
  Word16    t0, frac;
  Word16   *cur_exc;
  Word16    g, Gp, Gp2;
  Word16    excg[G729EV_G729_L_SUBFR], excs[G729EV_G729_L_SUBFR];
  Word32    L_acc, L_ener, L_k;
  Word16    max, hi, lo, inter_exc;
  Word16    sh;
  Word16    x1, x2;

  IF(cur_gain == 0)
  {
    FOR(i = 0; i < G729EV_G729_L_FRAME; i++)
    {
      exc[i] = 0;
#if(WMOPS)
      move16();
#endif
    }
    return;
  }



  /* Loop on subframes */

  cur_exc = exc;

  FOR(i_subfr = 0; i_subfr < G729EV_G729_L_FRAME; i_subfr = add(i_subfr, G729EV_G729_L_SUBFR))
  {

    /* generate random adaptive codebook & fixed codebook parameters */
    /*****************************************************************/
    temp1 = G729EV_G729_Random(seed);
    frac = sub(s_and(temp1, (Word16) 0x0003), 1);
    if (sub(frac, 2) == 0)
    {
      frac = 0;
#if(WMOPS)
      move16();
#endif
    }
    temp1 = shr(temp1, 2);
    t0 = add(s_and(temp1, (Word16) 0x003F), 40);
    temp1 = shr(temp1, 6);
    temp2 = s_and(temp1, (Word16) 0x0007);
    pos[0] = add(shl(temp2, 2), temp2); /* 5 * temp2 */
#if(WMOPS)
    move16();
#endif
    temp1 = shr(temp1, 3);
    sign[0] = s_and(temp1, (Word16) 0x0001);
    temp1 = shr(temp1, 1);
    temp2 = s_and(temp1, (Word16) 0x0007);
    temp2 = add(shl(temp2, 2), temp2);
    pos[1] = add(temp2, 1);     /* 5 * x + 1 */
#if(WMOPS)
    move16();
#endif
    temp1 = shr(temp1, 3);
    sign[1] = s_and(temp1, (Word16) 0x0001);
#if(WMOPS)
    move16();
#endif
    temp1 = G729EV_G729_Random(seed);
    temp2 = s_and(temp1, (Word16) 0x0007);
    temp2 = add(shl(temp2, 2), temp2);
    pos[2] = add(temp2, 2);     /* 5 * x + 2 */
#if(WMOPS)
    move16();
#endif
    temp1 = shr(temp1, 3);
    sign[2] = s_and(temp1, (Word16) 0x0001);
    temp1 = shr(temp1, 1);
    temp2 = s_and(temp1, (Word16) 0x000F);
    pos[3] = add(s_and(temp2, (Word16) 1), 3);  /* j+3 */
#if(WMOPS)
    move16();
#endif
    temp2 = s_and(shr(temp2, 1), (Word16) 7);
    temp2 = add(shl(temp2, 2), temp2);  /* 5i */
    pos[3] = add(pos[3], temp2);
#if(WMOPS)
    move16();
#endif
    temp1 = shr(temp1, 4);
    sign[3] = s_and(temp1, (Word16) 0x0001);
#if(WMOPS)
    move16();
#endif
    Gp = s_and(G729EV_G729_Random(seed), (Word16) 0x1FFF);  /* < 0.5 Q14 */
    Gp2 = shl(Gp, 1);           /* Q15 */


    /* Generate gaussian excitation */
    /********************************/
    L_acc = 0L;
    FOR(i = 0; i < G729EV_G729_L_SUBFR; i++)
    {
      temp1 = Gauss(seed);
      L_acc = L_mac(L_acc, temp1, temp1);
      excg[i] = temp1;
#if(WMOPS)
      move16();
#endif
    }

/*
    Compute fact = alpha x cur_gain * sqrt(L_SUBFR / Eg)
    with Eg = SUM(i=0->39) excg[i]^2
    and alpha = 0.5
    alpha x sqrt(L_SUBFR)/2 = 1 + FRAC1
*/
    L_acc = Inv_sqrt(L_shr(L_acc, 1));  /* Q30 */
    L_Extract(L_acc, &hi, &lo);
    /* cur_gain = cur_gainR << 3 */
    temp1 = mult_r(cur_gain, FRAC1);
    temp1 = add(cur_gain, temp1);
    /* <=> alpha x cur_gainR x 2^2 x sqrt(L_SUBFR) */

    L_acc = Mpy_32_16(hi, lo, temp1); /* fact << 17 */
    sh = norm_l(L_acc);
    temp1 = extract_h(L_shl(L_acc, sh));  /* fact << (sh+1) */

    sh = sub(sh, 14);
    FOR(i = 0; i < G729EV_G729_L_SUBFR; i++)
    {
      temp2 = mult_r(excg[i], temp1);
      temp2 = shr_r(temp2, sh); /* shl if sh < 0 */
      excg[i] = temp2;
#if(WMOPS)
      move16();
#endif
    }

    /* generate random  adaptive excitation */
    /****************************************/
    G729EV_G729_Pred_lt_3(cur_exc, t0, frac, G729EV_G729_L_SUBFR);
    FOR(i = 0; i < G729EV_G729_L_SUBFR; i++)
    {
      cur_exc[i] = shr(cur_exc[i], 1);
#if(WMOPS)
      move16();
#endif
    }

    /* compute adaptive + gaussian exc -> cur_exc */
    /**********************************************/
    max = 0;
#if(WMOPS)
    move16();
#endif
    FOR(i = 0; i < G729EV_G729_L_SUBFR; i++)
    {
      temp1 = mult_r(cur_exc[i], Gp2);
      temp1 = add(temp1, excg[i]);  /* may overflow */
      cur_exc[i] = temp1;
#if(WMOPS)
      move16();
#endif
      temp1 = abs_s(temp1);
      if (sub(temp1, max) > 0)
      {
        max = temp1;
#if(WMOPS)
        move16();
#endif
      }
    }

    /* rescale cur_exc -> excs */
    IF(max == 0)
    {
      sh = 0;
#if(WMOPS)
      move16();
#endif
    }
    ELSE
    {
      sh = sub(3, norm_s(max));
      if (sh <= 0)
      {
        sh = 0;
#if(WMOPS)
        move16();
#endif
      }
    }
    FOR(i = 0; i < G729EV_G729_L_SUBFR; i++)
    {
      excs[i] = shr(cur_exc[i], sh);
#if(WMOPS)
      move16();
#endif
    }

    /* Compute fixed code gain */
    /***************************/

    /**********************************************************/
    /*** Solve EQ(X) = 4 X**2 + 2 b X + c                     */
    /**********************************************************/

    L_ener = 0L;
#if(WMOPS)
    move32();
#endif
    FOR(i = 0; i < G729EV_G729_L_SUBFR; i++)
    {
      L_ener = L_mac(L_ener, excs[i], excs[i]);
    }                           /* ener x 2^(-2sh + 1) */

    /* inter_exc = b >> sh */
    inter_exc = 0;
#if(WMOPS)
    move16();
#endif
    FOR(i = 0; i < 4; i++)
    {
      j = pos[i];
#if(WMOPS)
      move16();
#endif
      IF(sign[i] == 0)
      {
        inter_exc = sub(inter_exc, excs[j]);
      }
      ELSE
      {
        inter_exc = add(inter_exc, excs[j]);
      }
    }

    /* Compute k = cur_gainR x cur_gainR x L_SUBFR */
    L_acc = L_mult(cur_gain, G729EV_G729_L_SUBFR);
    L_acc = L_shr(L_acc, 6);
    temp1 = extract_l(L_acc);   /* cur_gainR x L_SUBFR x 2^(-2) */
    L_k = L_mult(cur_gain, temp1);  /* k << 2 */
    temp1 = add(1, shl(sh, 1));
    L_acc = L_shr(L_k, temp1);  /* k x 2^(-2sh+1) */

    /* Compute delta = b^2 - 4 c */
    L_acc = L_sub(L_acc, L_ener); /* - 4 c x 2^(-2sh-1) */
    inter_exc = shr(inter_exc, 1);
    L_acc = L_mac(L_acc, inter_exc, inter_exc); /* 2^(-2sh-1) */
    sh = add(sh, 1);
    /* inter_exc = b x 2^(-sh) */
    /* L_acc = delta x 2^(-2sh+1) */

    IF(L_acc < 0)
    {

      /* adaptive excitation = 0 */
      G729EV_G729_Copy(excg, cur_exc, G729EV_G729_L_SUBFR);
      temp1 = s_or(abs_s(excg[(int) pos[0]]), abs_s(excg[(int) pos[1]]));
      temp2 = s_or(abs_s(excg[(int) pos[2]]), abs_s(excg[(int) pos[3]]));
      temp1 = s_or(temp1, temp2);
      IF(s_and(temp1, (Word16) 0x4000) == 0) sh = (Word16) 1;
      ELSE sh = (Word16) 2;
      inter_exc = 0;
#if(WMOPS)
      move16();
      move16();
#endif
      FOR(i = 0; i < 4; i++)
      {
        temp1 = shr(excg[(int) pos[i]], sh);
        IF(sign[i] == 0)
        {
          inter_exc = sub(inter_exc, temp1);
        }
        ELSE
        {
          inter_exc = add(inter_exc, temp1);
        }
      }                         /* inter_exc = b >> sh */
      L_Extract(L_k, &hi, &lo);
      L_acc = Mpy_32_16(hi, lo, K0);  /* k x (1- alpha^2) << 2 */
      temp1 = sub(shl(sh, 1), 1); /* temp1 > 0 */
      L_acc = L_shr(L_acc, temp1);  /* 4k x (1 - alpha^2) << (-2sh+1) */
      L_acc = L_mac(L_acc, inter_exc, inter_exc); /* delta << (-2sh+1) */
      Gp = 0;
#if(WMOPS)
      move16();
#endif
    }

    temp2 = Sqrt(L_acc);        /* >> sh */
    x1 = sub(temp2, inter_exc);
    x2 = negate(add(inter_exc, temp2)); /* x 2^(-sh+2) */
    if (sub(abs_s(x2), abs_s(x1)) < 0)
    {
      x1 = x2;
#if(WMOPS)
      move16();
#endif
    }
    temp1 = sub(2, sh);
    g = shr_r(x1, temp1);       /* shl if temp1 < 0 */
    IF(g >= 0)
    {
      if (sub(g, G_MAX) > 0)
      {
        g = G_MAX;
#if(WMOPS)
        move16();
#endif
      }
    }
    ELSE
    {
      if (add(g, G_MAX) < 0)
      {
        g = negate(G_MAX);
#if(WMOPS)
        move16();
#endif
      }
    }

    /* Update cur_exc with ACELP excitation */
    FOR(i = 0; i < 4; i++)
    {
      j = pos[i];
#if(WMOPS)
      move16();
#endif
      IF(sign[i] != 0)
      {
        cur_exc[j] = add(cur_exc[j], g);
      }
      ELSE
      {
        cur_exc[j] = sub(cur_exc[j], g);
      }
#if(WMOPS)
      move16();
#endif
    }

    FOR(i = 0; i < G729EV_G729_L_SUBFR; i++)
    {
      cur_exc[i] = shl(cur_exc[i], 1);
#if(WMOPS)
      move16();
#endif
    }

    tmp16 = add(pDecStat->i_subfr_cnt, 1);
    tmp16 = i_mult(tmp16, 3277);
    pDecStat->lp_gainp = add(pDecStat->lp_gainp, mult_r(tmp16, Gp));
    pDecStat->lp_gainc = add(pDecStat->lp_gainc, mult_r(tmp16, shl(g, 3)));
    pDecStat->tilt_code = extract_l(L_shr(L_add(-29491, 32767), 2));
    pDecStat->i_subfr_cnt = add(pDecStat->i_subfr_cnt, 1);

    cur_exc += G729EV_G729_L_SUBFR;


  }                             /* end of loop on subframes */

  return;
}

/*-----------------------------------------------------------*
 *         Local procedures                                  *
 *         ~~~~~~~~~~~~~~~~                                  *
 *-----------------------------------------------------------*/

/* Gaussian generation */
/***********************/
static Word16 Gauss(Word16 * seed)
{

/****  Xi = uniform v.a. in [-32768, 32767]       ****/
/****  Z = SUM(i=1->12) Xi / 2 x 32768 is N(0,1)  ****/
/****  output : Z x 512 < 2^12                    ****/

  Word16    i;
  Word16    temp;
  Word32    L_acc;

  L_acc = 0L;
#if(WMOPS)
  move32();
#endif
  FOR(i = 0; i < 12; i++)
  {
    L_acc = L_add(L_acc, L_deposit_l(G729EV_G729_Random(seed)));
  }
  L_acc = L_shr(L_acc, 7);
  temp = extract_l(L_acc);
  return (temp);
}

/* Square root function : returns sqrt(Num/2) */
/**********************************************/
static Word16 Sqrt(Word32 Num)
{
  Word16    i;

  Word16    Rez = (Word16) 0;
  Word16    Exp = (Word16) 0x4000;

  Word32    Acc, L_temp;

  FOR(i = 0; i < 14; i++)
  {
    Acc = L_mult(add(Rez, Exp), add(Rez, Exp));
    L_temp = L_sub(Num, Acc);
    if (L_temp >= 0L)
      Rez = add(Rez, Exp);
    Exp = shr(Exp, (Word16) 1);
  }
  return Rez;
}