g729ev_g729_gainpred.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
*/

/*---------------------------------------------------------------------------*
 *  G729EV_G729_Gain_predict()        : make gcode0(exp_gcode0)              *
 *  G729EV_G729_Gain_update()         : update table of past quantized energies.         *
 *                                                        (frame erasure)    *
 *    This function is used both Coder and Decoder.                          *
 *---------------------------------------------------------------------------*/

#include "stl.h"
#include "G729EV_G729_ld8k.h"
#include "G729EV_G729_TAB_ld8k.h"
#include "G729EV_MAIN_OPER_32B.h"
#include "G729EV_MAIN_DSPFUNC.h"

#ifdef WMOPS
#include "count.h"
#endif

/*---------------------------------------------------------------------------*
 * Function  G729EV_G729_Gain_predict                                        *
 * ~~~~~~~~~~~~~~~~~~~~~~                                                    *
 * MA prediction is performed on the innovation energy (in dB with mean      *
 * removed).                                                                 *
 *---------------------------------------------------------------------------*/
void G729EV_G729_Gain_predict(Word16 past_qua_en[], /* (i) Q10 :Past quantized energies        */
                              Word16 code[],        /* (i) Q13 :Innovative vector.             */
                              Word16 L_subfr,       /* (i)     :Subframe length.               */
                              Word16 * gcode0,      /* (o) Qxx :Predicted codebook gain        */
                              Word16 * exp_gcode0   /* (o)     :Q-Format(gcode0)               */
    )
{
  Word32    L_tmp;

  Word16    i, exp, frac;


  /*-------------------------------*
   * Energy coming from code       *
   *-------------------------------*/

  L_tmp = 0;
#ifdef WMOPS
  move32();
#endif
  FOR(i = 0; i < L_subfr; i++)
    L_tmp = L_mac(L_tmp, code[i], code[i]);

  /*-----------------------------------------------------------------*
   *  Compute: means_ener - 10log10(ener_code/ L_sufr)               *
   *  Note: mean_ener change from 36 dB to 30 dB because input/2     *
   *                                                                 *
   * = 30.0 - 10 log10( ener_code / lcode)  + 10log10(2^27)          *
   *                                          !!ener_code in Q27!!   *
   * = 30.0 - 3.0103 * log2(ener_code) + 10log10(40) + 10log10(2^27) *
   * = 30.0 - 3.0103 * log2(ener_code) + 16.02  + 81.278             *
   * = 127.298 - 3.0103 * log2(ener_code)                            *
   *-----------------------------------------------------------------*/

  Log2(L_tmp, &exp, &frac);     /* Q27->Q0 ^Q0 ^Q15       */
  L_tmp = Mpy_32_16(exp, frac, -24660); /* Q0 Q15 Q13 -> ^Q14     */
  /* hi:Q0+Q13+1            */
  /* lo:Q15+Q13-15+1        */
  /* -24660[Q13]=-3.0103    */
  L_tmp = L_mac(L_tmp, 32588, 32);  /* 32588*32[Q14]=127.298  */

  /*-----------------------------------------------------------------*
   * Compute gcode0.                                                 *
   *  = Sum(i=0,3) pred[i]*past_qua_en[i] - ener_code + mean_ener    *
   *-----------------------------------------------------------------*/

  L_tmp = L_shl(L_tmp, 10);     /* From Q14 to Q24 */
  FOR(i = 0; i < 4; i++)
    L_tmp = L_mac(L_tmp, pred[i], past_qua_en[i]);  /* Q13*Q10 ->Q24 */

  *gcode0 = extract_h(L_tmp);   /* From Q24 to Q8  */
#ifdef WMOPS
  move16();
#endif

  /*-----------------------------------------------------------------*
   * gcode0 = pow(10.0, gcode0/20)                                   *
   *        = pow(2, 3.3219*gcode0/20)                               *
   *        = pow(2, 0.166*gcode0)                                   *
   *-----------------------------------------------------------------*/

  L_tmp = L_mult(*gcode0, 5439);  /* *0.166 in Q15, result in Q24 */
  L_tmp = L_shr(L_tmp, 8);        /* From Q24 to Q16             */
  L_Extract(L_tmp, &exp, &frac);  /* Extract exponent of gcode0  */

  *gcode0 = extract_l(Pow2(14, frac));  /* Put 14 as exponent so that  */
  /* output of Pow2() will be:   */
  /* 16768 < Pow2() <= 32767     */
  *exp_gcode0 = sub(14, exp);
#ifdef WMOPS
  move16();
  move16();
#endif
}


/*---------------------------------------------------------------------------*
 * Function  G729EV_G729_Gain_update                                                     *
 * ~~~~~~~~~~~~~~~~~~~~~~                                                    *
 * update table of past quantized energies                                   *
 *---------------------------------------------------------------------------*/
void G729EV_G729_Gain_update(Word16 past_qua_en[],  /* (io) Q10 :Past quantized energies        */
                             Word32 L_gbk12         /* (i) Q13 : gbk1[indice1][1]+gbk2[indice2][1] */
    )
{
  Word32    L_acc;

  Word16    i, tmp;
  Word16    exp, frac;


  FOR(i = 3; i > 0; i--)
  {
    past_qua_en[i] = past_qua_en[i - 1];  /* Q10 */
#ifdef WMOPS
    move16();
#endif
  }
  /*----------------------------------------------------------------------*
   * -- past_qua_en[0] = 20*log10(gbk1[index1][1]+gbk2[index2][1]); --    *
   *    2 * 10 log10( gbk1[index1][1]+gbk2[index2][1] )                   *
   *  = 2 * 3.0103 log2( gbk1[index1][1]+gbk2[index2][1] )                *
   *  = 2 * 3.0103 log2( gbk1[index1][1]+gbk2[index2][1] )                *
   *                                                 24660:Q12(6.0205)    *
   *----------------------------------------------------------------------*/

  Log2(L_gbk12, &exp, &frac);         /* L_gbk12:Q13       */
  L_acc = L_Comp(sub(exp, 13), frac); /* L_acc:Q16           */
  tmp = extract_h(L_shl(L_acc, 13));  /* tmp:Q13           */
#ifdef WMOPS
  move16();
#endif
  past_qua_en[0] = mult(tmp, 24660);  /* past_qua_en[]:Q10 */
}