c3_14pf.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

/*
********************************************************************************
*
*      GSM AMR-NB speech codec   R98   Version 7.6.0   December 12, 2001
*                                R99   Version 3.3.0                
*                                REL-4 Version 4.1.0                
*
********************************************************************************
*
*      File             : c3_14pf.c
*      Purpose          : Searches a 14 bit algebraic codebook containing 3 pulses
*                         in a frame of 40 samples.
*
********************************************************************************
*/

/*
********************************************************************************
*                         MODULE INCLUDE FILE AND VERSION ID
********************************************************************************
*/
#include "c3_14pf.h"
const char c3_14pf_id[] = "@(#)$Id $" c3_14pf_h;
 
/*
********************************************************************************
*                         INCLUDE FILES
********************************************************************************
*/
#include "typedef.h"
#include "basic_op.h"
#include "count.h"
#include "inv_sqrt.h"
#include "cnst.h"
#include "cor_h.h"
#include "set_sign.h"

/*
********************************************************************************
*                         LOCAL VARIABLES AND TABLES
********************************************************************************
*/
#define NB_PULSE  3

/*
********************************************************************************
*                         DECLARATION OF PROTOTYPES
********************************************************************************
*/
static void search_3i40(
    Word16 dn[],        /* i : correlation between target and h[]            */
    Word16 dn2[],       /* i : maximum of corr. in each track.               */
    Word16 rr[][L_CODE],/* i : matrix of autocorrelation                     */
    Word16 codvec[]     /* o : algebraic codebook vector                     */
);

static Word16 build_code(   
    Word16 codvec[],    /* i : algebraic codebook vector                     */
    Word16 dn_sign[],   /* i : sign of dn[]                                  */
    Word16 cod[],       /* o : algebraic (fixed) codebook excitation         */
    Word16 h[],         /* i : impulse response of weighted synthesis filter */
    Word16 y[],         /* o : filtered fixed codebook excitation            */
    Word16 sign[]       /* o : sign of 3 pulses                              */
);

/*
********************************************************************************
*                         PUBLIC PROGRAM CODE
********************************************************************************
*/
/*************************************************************************
 *
 *  FUNCTION:  code_3i40_14bits()
 *
 *  PURPOSE:  Searches a 14 bit algebraic codebook containing 3 pulses
 *            in a frame of 40 samples.
 *
 *  DESCRIPTION:
 *    The code length is 40, containing 3 nonzero pulses: i0...i2.
 *    All pulses can have two possible amplitudes: +1 or -1.
 *    Pulse i0 can have 8 possible positions, pulses i1 and i2 can have
 *    2x8=16 positions.
 *
 *       i0 :  0, 5, 10, 15, 20, 25, 30, 35.
 *       i1 :  1, 6, 11, 16, 21, 26, 31, 36.
 *             3, 8, 13, 18, 23, 28, 33, 38.
 *       i2 :  2, 7, 12, 17, 22, 27, 32, 37.
 *             4, 9, 14, 19, 24, 29, 34, 39.
 *
 *************************************************************************/

Word16 code_3i40_14bits(
    Word16 x[],         /* i : target vector                                 */
    Word16 h[],         /* i : impulse response of weighted synthesis filter */
                        /*     h[-L_subfr..-1] must be set to zero.          */
    Word16 T0,          /* i : Pitch lag                                     */
    Word16 pitch_sharp, /* i : Last quantized pitch gain                     */
    Word16 code[],      /* o : Innovative codebook                           */
    Word16 y[],         /* o : filtered fixed codebook excitation            */
    Word16 * sign       /* o : Signs of 3 pulses                             */
)
{
    Word16 codvec[NB_PULSE];
    Word16 dn[L_CODE], dn2[L_CODE], dn_sign[L_CODE];
    Word16 rr[L_CODE][L_CODE];
    Word16 i, index, sharp;

    sharp = shl(pitch_sharp, 1);
    test ();
    if (sub(T0, L_CODE) < 0)
    {
       for (i = T0; i < L_CODE; i++) {
          h[i] = add(h[i], mult(h[i - T0], sharp));      move16 ();
       }
    }
    
    cor_h_x(h, x, dn, 1);
    set_sign(dn, dn_sign, dn2, 6);
    cor_h(h, dn_sign, rr);
    search_3i40(dn, dn2, rr, codvec);
                                    move16 (); /* function result */
    index = build_code(codvec, dn_sign, code, h, y, sign);

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

    test ();
    if (sub(T0, L_CODE) < 0)
    {
       for (i = T0; i < L_CODE; i++) { 
          code[i] = add(code[i], mult(code[i - T0], sharp));    move16 ();
       }
    }
    return index;
}

/*
********************************************************************************
*                         PRIVATE PROGRAM CODE
********************************************************************************
*/

/*************************************************************************
 *
 *  FUNCTION  search_3i40()
 *
 *  PURPOSE: Search the best codevector; determine positions of the 3 pulses
 *           in the 40-sample frame.
 *
 *************************************************************************/

#define _1_2    (Word16)(32768L/2)
#define _1_4    (Word16)(32768L/4)
#define _1_8    (Word16)(32768L/8)
#define _1_16   (Word16)(32768L/16)

static void search_3i40(
    Word16 dn[],         /* i : correlation between target and h[] */
    Word16 dn2[],        /* i : maximum of corr. in each track.    */
    Word16 rr[][L_CODE], /* i : matrix of autocorrelation          */
    Word16 codvec[]      /* o : algebraic codebook vector          */
)
{
    Word16 i0, i1, i2;
    Word16 ix = 0; /* initialization only needed to keep gcc silent */
    Word16 ps = 0; /* initialization only needed to keep gcc silent */
    Word16 i, pos, track1, track2, ipos[NB_PULSE];
    Word16 psk, ps0, ps1, sq, sq1;
    Word16 alpk, alp, alp_16;
    Word32 s, alp0, alp1;

    psk = -1;     move16 ();
    alpk = 1;     move16 ();
    for (i = 0; i < NB_PULSE; i++)
    {
       codvec[i] = i;    move16 ();
    }

    for (track1 = 1; track1 < 4; track1 += 2)
    {
       for (track2 = 2; track2 < 5; track2 += 2)
       {		
          /* fix starting position */

          ipos[0] = 0;       move16 ();
          ipos[1] = track1;  move16 ();
          ipos[2] = track2;  move16 ();
          
          /*------------------------------------------------------------------*
           * main loop: try 3 tracks.                                         *
           *------------------------------------------------------------------*/
          
          for (i = 0; i < NB_PULSE; i++)
          {
             /*----------------------------------------------------------------*
              * i0 loop: try 8 positions.                                      *
              *----------------------------------------------------------------*/
             
             move16 (); /* account for ptr. init. (rr[io]) */
             for (i0 = ipos[0]; i0 < L_CODE; i0 += STEP)
             {
                test ();
                if (dn2[i0] >= 0)
                {
                   ps0 = dn[i0];  move16 ();
                   alp0 = L_mult(rr[i0][i0], _1_4);
                   
                   /*----------------------------------------------------------------*
                    * i1 loop: 8 positions.                                          *