g729ev_fec_onset.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 "G729EV_MAIN_defines.h"
#include "G729EV_G729_defines.h"
#include "G729EV_FEC_fer.h"
#include "G729EV_FEC_tools.h"
#include "G729EV_G729_ld8k.h"
#include "stl.h"
#include "G729EV_MAIN_OPER_32B.h"
#include "G729EV_MAIN_DSPFUNC.h"

/************************************************************************************/
/* G729EV_FEC_mod_adapt_codebook :  Artificial reconstruction of the adaptive       */
/*                                  codebook memory after the lost of an ONSET      */
/* - Decode location and sign of the last pulse                                     */
/* - Reset adaptive codebook memory                                                 */
/* - Find LP filter impulse response energy                                         */
/* - Scale pulse "prototype" energy                                                 */
/* - Place pulse "prototype" at the right position in the adaptive codebooke memory */
/* - Update adaptive codebook memory                                                */
/* - Find signal classification                                                     */
/************************************************************************************/
void      G729EV_FEC_mod_adapt_codebook(Word16 * exc,       /* i/o : exc vector to modify                                               */
                                        Word16 puls_pos,    /* i   : Last pulse position desired                                        */
                                        Word16 * pitch_buf, /* i   : containt pitch modified in function of bfi_pitch and new pitch   Q6 */
                                        Word32 enr_q,       /* i   : energy provide by the encoder                                    Q0 */
                                        Word16 * Aq         /* i   : Lsp coefficient                                                     */
    )
{
  Word16    T0, P0, onset_len, sign, i, len;
  Word16    h1[G729EV_G729_L_SUBFR], mem[G729EV_G729_M], exc_tmp[G729EV_FEC_L_MEM];
  Word16   *pt_end, *pt_exc, enr_LP, gain, H_low_s[5], exp_gain, exp2, tmp;
  Word32    L_tmp;
  Word16    Q_exc;

  sign = 0;
  Q_exc = 0;
#if(WMOPS)
  move16();
  move16();
  move16();
#endif
  T0 = shr(pitch_buf[3], G729EV_FEC_SQPIT);
  IF(sub(T0, 2 * G729EV_G729_L_SUBFR) < 0)
  {
    onset_len = 2 * G729EV_G729_L_SUBFR;
  }
  ELSE
  {
    onset_len = T0;
  }

#if(WMOPS)
  move16();
#endif
  P0 = puls_pos;

  IF(P0 < 0)
  {
#if(WMOPS)
    move16();
#endif
    sign = (Word16) 1;
    P0 = negate(P0);
  }

  IF(sub(T0, 128) >= 0)
  {
    P0 = shl(P0, 2);
    P0 = add(P0, 2);
  }
  ELSE if   (sub(T0, 64) >= 0)
  {
    P0 = shl(P0, 1);
    P0 = add(P0, 1);
  }

  if (sub(P0, 160) > 0)
  {
    P0 = 160;                   /* Should never be the case, however... */
#if(WMOPS)
    move16();
#endif
  }

  G729EV_G729_Set_zero(exc_tmp, G729EV_FEC_L_MEM);  /* Reset excitation vector            */

   /*------------------------------------------------------------------------------------------*
    * Find LP filter impulse response energy   
    *------------------------------------------------------------------------------------------*/

  G729EV_G729_Set_zero(h1, G729EV_G729_L_SUBFR);  /* Find the impulse response          */
  G729EV_G729_Set_zero(mem, G729EV_G729_M);
  h1[0] = 1024;
#if(WMOPS)
  move16();
#endif
  G729EV_G729_Syn_filt(Aq, h1, h1, G729EV_G729_L_SUBFR, mem, 0);
  enr_LP = extract_h(G729EV_Dot_product12(h1, h1, G729EV_G729_L_SUBFR, &exp_gain));
  exp_gain = sub(exp_gain, 10 + 10);  /* h1 in Q10 */

  /* divide by LP filter E, scaled by transmitted E   */
  /* gain = (float)sqrt( enr_q / enr_LP ); */

  if (enr_q == 0)
  {
    enr_q = 1L;
#if(WMOPS)
    move32();
#endif
  }

  exp2 = norm_l(enr_q);
  tmp = extract_h(L_shl(enr_q, exp2));
  tmp = mult(tmp, 24576);       /* multpiply by 1.5 */

  IF(sub(tmp, 16384) < 0)
  {
    exp2 = add(exp2, 1);
    tmp = shl(tmp, 1);
  }
  exp2 = sub(exp2, 1);
  exp2 = sub(31, exp2);         /* in Q15 */


  IF(sub(enr_LP, tmp) > 0)
  {
    enr_LP = shr(enr_LP, 1);
    exp_gain = add(exp_gain, 1);
  }

  tmp = div_s(enr_LP, tmp);
  exp2 = sub(exp_gain, exp2);

  L_tmp = L_deposit_h(tmp);
  Isqrt_n(&L_tmp, &exp2);
  gain = round(L_tmp);

  gain = mult_r(gain, 31457);   /* multiply by .96 like floating point   */
  exp2 = add(sub(exp2, 15), Q_exc); /* from Q15 to Q_exc */

  /* Find if rescaling needed */
  tmp = extract_h(L_mult(G729EV_FEC_h_low[2], gain));
  exp_gain = norm_s(tmp);
  tmp = sub(exp_gain, exp2);    /* difference */

  IF(tmp < 0)                   /* Need to correct scaling */
  {
    Q_exc = add(Q_exc, tmp);
    exp2 = add(exp2, tmp);
  }
  /* Scale pulse "prototype" energy */
  /* Generate the scaled pulse */
  FOR(i = 0; i < G729EV_FEC_L_FIR_FER; i++)
  {
    L_tmp = L_mult(gain, G729EV_FEC_h_low[i]);  /* Q_exc*Q15 -> Q_exc */
    H_low_s[i] = round(L_shl(L_tmp, exp2));
#if(WMOPS)
    move16();
#endif
  }

   /*------------------------------------------------------------------------------------------*
    * Place pulse "prototype" at the right position in the adaptive codebooke memory          
    *------------------------------------------------------------------------------------------*/
#if(WMOPS)
  move16();
#endif

  pt_exc = exc_tmp + sub(G729EV_MAIN_L_FRAME2, add(add(1, G729EV_FEC_L_FIR_FER / 2), P0));  /* beginning of the 1st pulse         */
  pt_end = exc_tmp + onset_len;
  len = pt_exc - pt_end;

  if (sub(len, G729EV_FEC_L_FIR_FER) > 0)
  {
    len = G729EV_FEC_L_FIR_FER;
#if(WMOPS)
    move16();
#endif
  }
  IF(!sign)
  {

    FOR(i = 0; i < len; i++)
    {                           /* The filter response would have E=1 in full band. */
      pt_exc[i] = add(pt_exc[i], H_low_s[i]);
#if(WMOPS)
      move16();
#endif
    }
  }
  ELSE
  {
    FOR(i = 0; i < len; i++)
    {                           /* The filter response would have E=1 in full band. */
      pt_exc[i] = sub(pt_exc[i], H_low_s[i]);
#if(WMOPS)
      move16();
#endif
    }
  }
  G729EV_G729_Copy(&exc_tmp[G729EV_MAIN_L_FRAME2 - G729EV_G729_PIT_MAX - G729EV_G729_L_INTERPOL], exc,
                   G729EV_G729_PIT_MAX + G729EV_G729_L_INTERPOL);
}