acelp_ca.c

C源程序---G.729a语音代码G.729a语音代码

/*
   ITU-T G.729A Speech Coder    ANSI-C Source Code
   Version 1.1    Last modified: September 1996

   Copyright (c) 1996,
   AT&T, France Telecom, NTT, Universite de Sherbrooke
   All rights reserved.
*/

/*---------------------------------------------------------------------------*
 *  Function  ACELP_Code_A()                                                 *
 *  ~~~~~~~~~~~~~~~~~~~~~~~~                                                 *
 *   Find Algebraic codebook for G.729A                                      *
 *--------------------------------------------------------------------------*/

#include "typedef.h"
#include "basic_op.h"
#include "ld8a.h"

/* Constants defined in ld8a.h */
/*  L_SUBFR   -> Lenght of subframe.                                        */
/*  NB_POS    -> Number of positions for each pulse.                        */
/*  STEP      -> Step betweem position of the same pulse.                   */
/*  MSIZE     -> Size of vectors for cross-correlation between two pulses.  */


/* local routines definition */

static void Cor_h(
     Word16 *H,         /* (i) Q12 :Impulse response of filters */
     Word16 *rr         /* (o)     :Correlations of H[]         */
);
static Word16 D4i40_17_fast(/*(o) : Index of pulses positions.               */
  Word16 dn[],          /* (i)    : Correlations between h[] and Xn[].       */
  Word16 *rr,           /* (i)    : Correlations of impulse response h[].    */
  Word16 h[],           /* (i) Q12: Impulse response of filters.             */
  Word16 cod[],         /* (o) Q13: Selected algebraic codeword.             */
  Word16 y[],           /* (o) Q12: Filtered algebraic codeword.             */
  Word16 *sign          /* (o)    : Signs of 4 pulses.                       */
);

 /*-----------------------------------------------------------------*
  * Main ACELP function.                                            *
  *-----------------------------------------------------------------*/

Word16  ACELP_Code_A(    /* (o)     :index of pulses positions    */
  Word16 x[],            /* (i)     :Target vector                */
  Word16 h[],            /* (i) Q12 :Inpulse response of filters  */
  Word16 T0,             /* (i)     :Pitch lag                    */
  Word16 pitch_sharp,    /* (i) Q14 :Last quantized pitch gain    */
  Word16 code[],         /* (o) Q13 :Innovative codebook          */
  Word16 y[],            /* (o) Q12 :Filtered innovative codebook */
  Word16 *sign           /* (o)     :Signs of 4 pulses            */
)
{
  Word16 i, index, sharp;
  Word16 Dn[L_SUBFR];
  Word16 rr[DIM_RR];

 /*-----------------------------------------------------------------*
  * Include fixed-gain pitch contribution into impulse resp. h[]    *
  * Find correlations of h[] needed for the codebook search.        *
  *-----------------------------------------------------------------*/

  sharp = shl(pitch_sharp, 1);          /* From Q14 to Q15 */
  if (T0 < L_SUBFR)
     for (i = T0; i < L_SUBFR; i++)     /* h[i] += pitch_sharp*h[i-T0] */
       h[i] = add(h[i], mult(h[i-T0], sharp));

  Cor_h(h, rr);

 /*-----------------------------------------------------------------*
  * Compute correlation of target vector with impulse response.     *
  *-----------------------------------------------------------------*/

  Cor_h_X(h, x, Dn);

 /*-----------------------------------------------------------------*
  * Find innovative codebook.                                       *
  *-----------------------------------------------------------------*/

  index = D4i40_17_fast(Dn, rr, h, code, y, sign);

 /*-----------------------------------------------------------------*
  * Compute innovation vector gain.                                 *
  * Include fixed-gain pitch contribution into code[].              *
  *-----------------------------------------------------------------*/

  if(T0 < L_SUBFR)
     for (i = T0; i < L_SUBFR; i++)    /* code[i] += pitch_sharp*code[i-T0] */
       code[i] = add(code[i], mult(code[i-T0], sharp));

  return index;
}



/*--------------------------------------------------------------------------*
 *  Function  Cor_h()                                                       *
 *  ~~~~~~~~~~~~~~~~~                                                       *
 * Compute  correlations of h[]  needed for the codebook search.            *
 *--------------------------------------------------------------------------*/

static void Cor_h(
  Word16 *H,     /* (i) Q12 :Impulse response of filters */
  Word16 *rr     /* (o)     :Correlations of H[]         */
)
{
  Word16 *rri0i0, *rri1i1, *rri2i2, *rri3i3, *rri4i4;
  Word16 *rri0i1, *rri0i2, *rri0i3, *rri0i4;
  Word16 *rri1i2, *rri1i3, *rri1i4;
  Word16 *rri2i3, *rri2i4;

  Word16 *p0, *p1, *p2, *p3, *p4;

  Word16 *ptr_hd, *ptr_hf, *ptr_h1, *ptr_h2;
  Word32 cor;
  Word16 i, k, ldec, l_fin_sup, l_fin_inf;
  Word16 h[L_SUBFR];

 /* Scaling h[] for maximum precision */

  cor = 0;
  for(i=0; i<L_SUBFR; i++)
    cor = L_mac(cor, H[i], H[i]);

  if(sub(extract_h(cor),32000) > 0)
  {
    for(i=0; i<L_SUBFR; i++) {
      h[i] = shr(H[i], 1);
    }
  }
  else
  {
    k = norm_l(cor);
    k = shr(k, 1);

    for(i=0; i<L_SUBFR; i++) {
      h[i] = shl(H[i], k);
    }
  }


 /*------------------------------------------------------------*
  * Compute rri0i0[], rri1i1[], rri2i2[], rri3i3 and rri4i4[]  *
  *------------------------------------------------------------*/
  /* Init pointers */
  rri0i0 = rr;
  rri1i1 = rri0i0 + NB_POS;
  rri2i2 = rri1i1 + NB_POS;
  rri3i3 = rri2i2 + NB_POS;
  rri4i4 = rri3i3 + NB_POS;
  rri0i1 = rri4i4 + NB_POS;
  rri0i2 = rri0i1 + MSIZE;
  rri0i3 = rri0i2 + MSIZE;
  rri0i4 = rri0i3 + MSIZE;
  rri1i2 = rri0i4 + MSIZE;
  rri1i3 = rri1i2 + MSIZE;
  rri1i4 = rri1i3 + MSIZE;
  rri2i3 = rri1i4 + MSIZE;
  rri2i4 = rri2i3 + MSIZE;

  p0 = rri0i0 + NB_POS-1;   /* Init pointers to last position of rrixix[] */
  p1 = rri1i1 + NB_POS-1;
  p2 = rri2i2 + NB_POS-1;
  p3 = rri3i3 + NB_POS-1;
  p4 = rri4i4 + NB_POS-1;

  ptr_h1 = h;
  cor    = 0;
  for(i=0;  i<NB_POS; i++)
  {
    cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
    *p4-- = extract_h(cor);

    cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
    *p3-- = extract_h(cor);

    cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
    *p2-- = extract_h(cor);

    cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
    *p1-- = extract_h(cor);

    cor = L_mac(cor, *ptr_h1, *ptr_h1); ptr_h1++;
    *p0-- = extract_h(cor);
  }

 /*-----------------------------------------------------------------*
  * Compute elements of: rri2i3[], rri1i2[], rri0i1[] and rri0i4[]  *
  *-----------------------------------------------------------------*/

  l_fin_sup = MSIZE-1;
  l_fin_inf = l_fin_sup-(Word16)1;
  ldec = NB_POS+1;

  ptr_hd = h;
  ptr_hf = ptr_hd + 1;

  for(k=0; k<NB_POS; k++) {

          p3 = rri2i3 + l_fin_sup;
          p2 = rri1i2 + l_fin_sup;
          p1 = rri0i1 + l_fin_sup;
          p0 = rri0i4 + l_fin_inf;

          cor = 0;
          ptr_h1 = ptr_hd;
          ptr_h2 =  ptr_hf;

          for(i=k+(Word16)1; i<NB_POS; i++ ) {

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p3 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p2 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p1 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p0 = extract_h(cor);

                  p3 -= ldec;
                  p2 -= ldec;
                  p1 -= ldec;
                  p0 -= ldec;
          }
          cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
          cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
          *p3 = extract_h(cor);

          cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
          *p2 = extract_h(cor);

          cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
          *p1 = extract_h(cor);

          l_fin_sup -= NB_POS;
          l_fin_inf--;
          ptr_hf += STEP;
  }

 /*---------------------------------------------------------------------*
  * Compute elements of: rri2i4[], rri1i3[], rri0i2[], rri1i4[], rri0i3 *
  *---------------------------------------------------------------------*/

  ptr_hd = h;
  ptr_hf = ptr_hd + 2;
  l_fin_sup = MSIZE-1;
  l_fin_inf = l_fin_sup-(Word16)1;
  for(k=0; k<NB_POS; k++) {

          p4 = rri2i4 + l_fin_sup;
          p3 = rri1i3 + l_fin_sup;
          p2 = rri0i2 + l_fin_sup;
          p1 = rri1i4 + l_fin_inf;
          p0 = rri0i3 + l_fin_inf;

          cor = 0;
          ptr_h1 = ptr_hd;
          ptr_h2 =  ptr_hf;
          for(i=k+(Word16)1; i<NB_POS; i++ ) {

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p4 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p3 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p2 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p1 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p0 = extract_h(cor);

                  p4 -= ldec;
                  p3 -= ldec;
                  p2 -= ldec;
                  p1 -= ldec;
                  p0 -= ldec;
          }
          cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
          *p4 = extract_h(cor);

          cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
          *p3 = extract_h(cor);

          cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
          *p2 = extract_h(cor);


          l_fin_sup -= NB_POS;
          l_fin_inf--;
          ptr_hf += STEP;
  }

 /*----------------------------------------------------------------------*
  * Compute elements of: rri1i4[], rri0i3[], rri2i4[], rri1i3[], rri0i2  *
  *----------------------------------------------------------------------*/

  ptr_hd = h;
  ptr_hf = ptr_hd + 3;
  l_fin_sup = MSIZE-1;
  l_fin_inf = l_fin_sup-(Word16)1;
  for(k=0; k<NB_POS; k++) {

          p4 = rri1i4 + l_fin_sup;
          p3 = rri0i3 + l_fin_sup;
          p2 = rri2i4 + l_fin_inf;
          p1 = rri1i3 + l_fin_inf;
          p0 = rri0i2 + l_fin_inf;

          ptr_h1 = ptr_hd;
          ptr_h2 =  ptr_hf;
          cor = 0;
          for(i=k+(Word16)1; i<NB_POS; i++ ) {

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p4 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p3 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p2 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p1 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p0 = extract_h(cor);

                  p4 -= ldec;
                  p3 -= ldec;
                  p2 -= ldec;
                  p1 -= ldec;
                  p0 -= ldec;
          }
          cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
          *p4 = extract_h(cor);

          cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
          *p3 = extract_h(cor);

          l_fin_sup -= NB_POS;
          l_fin_inf--;
          ptr_hf += STEP;
  }

 /*----------------------------------------------------------------------*
  * Compute elements of: rri0i4[], rri2i3[], rri1i2[], rri0i1[]          *
  *----------------------------------------------------------------------*/

  ptr_hd = h;
  ptr_hf = ptr_hd + 4;
  l_fin_sup = MSIZE-1;
  l_fin_inf = l_fin_sup-(Word16)1;
  for(k=0; k<NB_POS; k++) {

          p3 = rri0i4 + l_fin_sup;
          p2 = rri2i3 + l_fin_inf;
          p1 = rri1i2 + l_fin_inf;
          p0 = rri0i1 + l_fin_inf;

          ptr_h1 = ptr_hd;
          ptr_h2 =  ptr_hf;
          cor = 0;
          for(i=k+(Word16)1; i<NB_POS; i++ ) {

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p3 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p2 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p1 = extract_h(cor);

                  cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
                  *p0 = extract_h(cor);

                  p3 -= ldec;
                  p2 -= ldec;
                  p1 -= ldec;
                  p0 -= ldec;
          }
          cor = L_mac(cor, *ptr_h1, *ptr_h2); ptr_h1++; ptr_h2++;
          *p3 = extract_h(cor);

          l_fin_sup -= NB_POS;
          l_fin_inf--;
          ptr_hf += STEP;
  }
  return;
}



/*------------------------------------------------------------------------*
 * Function  D4i40_17_fast()                                              *
 *           ~~~~~~~~~                                                    *
 * Algebraic codebook for ITU 8kb/s.                                      *
 *  -> 17 bits; 4 pulses in a frame of 40 samples                         *
 *                                                                        *
 *------------------------------------------------------------------------*
 * The code length is 40, containing 4 nonzero pulses i0, i1, i2, i3.     *
 * Each pulses can have 8 possible positions (positive or negative)       *
 * except i3 that have 16 possible positions.                             *
 *                                                                        *
 * i0 (+-1) : 0, 5, 10, 15, 20, 25, 30, 35                                *
 * i1 (+-1) : 1, 6, 11, 16, 21, 26, 31, 36                                *
 * i2 (+-1) : 2, 7, 12, 17, 22, 27, 32, 37                                *
 * i3 (+-1) : 3, 8, 13, 18, 23, 28, 33, 38                                *
 *            4, 9, 14, 19, 24, 29, 34, 39                                *
 *------------------------------------------------------------------------*/

static Word16 D4i40_17_fast(/*(o) : Index of pulses positions.               */
  Word16 dn[],          /* (i)    : Correlations between h[] and Xn[].       */
  Word16 rr[],          /* (i)    : Correlations of impulse response h[].    */
  Word16 h[],           /* (i) Q12: Impulse response of filters.             */
  Word16 cod[],         /* (o) Q13: Selected algebraic codeword.             */
  Word16 y[],           /* (o) Q12: Filtered algebraic codeword.             */
  Word16 *sign          /* (o)    : Signs of 4 pulses.                       */
)
{
  Word16 i0, i1, i2, i3, ip0, ip1, ip2, ip3;
  Word16 i, j, ix, iy, track, trk, max;
  Word16 prev_i0, i1_offset;
  Word16 psk, ps, ps0, ps1, ps2, sq, sq2;
  Word16 alpk, alp, alp_16;
  Word32 s, alp0, alp1, alp2;
  Word16 *p0, *p1, *p2, *p3, *p4;
  Word16 sign_dn[L_SUBFR], sign_dn_inv[L_SUBFR], *psign;
  Word16 tmp_vect[NB_POS];
  Word16 *rri0i0, *rri1i1, *rri2i2, *rri3i3, *rri4i4;
  Word16 *rri0i1, *rri0i2, *rri0i3, *rri0i4;
  Word16 *rri1i2, *rri1i3, *rri1i4;
  Word16 *rri2i3, *rri2i4;

  Word16  *ptr_rri0i3_i4;
  Word16  *ptr_rri1i3_i4;
  Word16  *ptr_rri2i3_i4;
  Word16  *ptr_rri3i3_i4;

     /* Init pointers */
   rri0i0 = rr;
   rri1i1 = rri0i0 + NB_POS;
   rri2i2 = rri1i1 + NB_POS;
   rri3i3 = rri2i2 + NB_POS;
   rri4i4 = rri3i3 + NB_POS;
   rri0i1 = rri4i4 + NB_POS;
   rri0i2 = rri0i1 + MSIZE;
   rri0i3 = rri0i2 + MSIZE;
   rri0i4 = rri0i3 + MSIZE;
   rri1i2 = rri0i4 + MSIZE;
   rri1i3 = rri1i2 + MSIZE;
   rri1i4 = rri1i3 + MSIZE;
   rri2i3 = rri1i4 + MSIZE;