funcg722.c

ITU-T G.191中包含的G.722语音压缩编解码程序

*/
#define AH   s->ah
#define BH   s->bh
#define DETH s->deth
#define DH  s->dh 
#define NBH  s->nbh
#define PH  s->ph 
#define RH  s->rh 
#define SH   s->sh
#define SPH  s->sph 
#define SZH  s->szh

Word16 
hsbdec (ih, rs, s)
Word16 ih;
Word16 rs;
g722_state *s;
{
  Word16          nbph, yh;

  if (rs == 1)
  {
    DETH = 8;
    SH = SPH = SZH = NBH = 0;
    AH[1] = AH[2] = 0;
    BH[1] = BH[2] = BH[3] = BH[4] = BH[5] = BH[6] = 0;
    DH[0] = DH[1] = DH[2] = DH[3] = DH[4] = DH[5] = DH[6] = 0;
    PH[0] = PH[1] = PH[2] = 0;
    RH[0] = RH[1] = RH[2] = 0;
    return (0);
  }

  DH[0] = invqah (ih, DETH);
  nbph = logsch (ih, NBH);
  NBH = nbph;
  DETH = scaleh (nbph);
  PH[0] = parrec (DH[0], SZH);
  RH[0] = recons (SH, DH[0]);
  upzero (DH, BH);
  uppol2 (AH, PH);
  uppol1 (AH, PH);
  SZH = filtez (DH, BH);
  SPH = filtep (RH, AH);
  SH = predic (SPH, SZH);
  yh = limit (RH[0]);

  return (yh);
}
#undef AH
#undef BH
#undef DETH
#undef DH
#undef NBH
#undef PH
#undef RH
#undef SH
#undef SPH
#undef SZH
/* ........................ End of hsbdec() ........................ */


/*___________________________________________________________________________
                                                                            
    Function Name : quantl                                                  
                                                                            
    Purpose :                                                               
                                                                            
     .                  
                                                                            
    Inputs :                                                                
                                                                            
                                                                            
    Outputs :                                                               
                                                                            
     none                                                                   
                                                                            
    Return Value :                                                          
                                                                            
 ___________________________________________________________________________
*/
Word16 
quantl (el, detl)
Word16 el;
Word16 detl;
{
 /* table to read IL frorm SIL and MIL: misil(sil(0,1),mil(1,31)) */

  static Word16   misil[2][32] =
  {
    {0x0000, 0x003F, 0x003E, 0x001F, 0x001E, 0x001D, 0x001C, 0x001B,
     0x001A, 0x0019, 0x0018, 0x0017, 0x0016, 0x0015, 0x0014, 0x0013,
     0x0012, 0x0011, 0x0010, 0x000F, 0x000E, 0x000D, 0x000C, 0x000B,
     0x000A, 0x0009, 0x0008, 0x0007, 0x0006, 0x0005, 0x0004, 0x0000},
    {0x0000, 0x003D, 0x003C, 0x003B, 0x003A, 0x0039, 0x0038, 0x0037,
     0x0036, 0x0035, 0x0034, 0x0033, 0x0032, 0x0031, 0x0030, 0x002F,
     0x002E, 0x002D, 0x002C, 0x002B, 0x002A, 0x0029, 0x0028, 0x0027,
     0x0026, 0x0025, 0x0024, 0x0023, 0x0022, 0x0021, 0x0020, 0x0000}
  };

 /* 6 levels quantizer level od decision */
  static Word16   q6[31] =
  {
    0, 35, 72, 110, 150, 190, 233, 276,
    323, 370, 422, 473, 530, 587, 650, 714,
    786, 858, 940, 1023, 1121, 1219, 1339, 1458,
    1612, 1765, 1980, 2195, 2557, 2919, 3200
  };



  Word16          sil, mil, wd, val;

  sil = shr (el, 15);
  wd = (sil == 0) ? el : sub (MAX_16, (el & MAX_16));

  mil = 0;
  val = mult (q6[mil] * 8, detl);
  while (val <= wd)
  {
    if (mil == 30)
    {
      break;
    }
    else
    {
      ++mil;
      val = mult (q6[mil] * 8, detl);
    }
  }

  return (misil[++sil][mil]);
}
/* ..................... End of quantl() ..................... */


/*___________________________________________________________________________
                                                                            
    Function Name quanth:                                                   
                                                                            
    Purpose :                                                               
                                                                            
     .                  
                                                                            
    Inputs :                                                                
                                                                            
                                                                            
    Outputs :                                                               
                                                                            
     none                                                                   
                                                                            
    Return Value :                                                          
                                                                            
 ___________________________________________________________________________
*/
Word16 
quanth (eh, deth)
Word16 eh;
Word16 deth;
{
  static Word16   misih[2][3] =
  {
    {0, 1, 0},
    {0, 3, 2}
  };
  static Word16   q2 = 564;

  Word16          sih, mih, wd;

  sih = shr (eh, 15);
  wd = (sih == 0) ? eh : sub (MAX_16, (eh & MAX_16));
  if (wd >= mult (shl (q2, 3), deth))
  {
    mih = 2;
  }
  else
  {
    mih = 1;
  }

  return (misih[++sih][mih]);
}
/* ..................... End of quanth() ..................... */


/*___________________________________________________________________________
                                                                            
    Function Name : filtep                                                  
                                                                            
    Purpose :                                                               
                                                                            
     .                  
                                                                            
    Inputs :                                                                
                                                                            
                                                                            
    Outputs :                                                               
                                                                            
     none                                                                   
                                                                            
    Return Value :                                                          
                                                                            
 ___________________________________________________________________________
*/
Word16 
filtep (rlt, al)
Word16 rlt [];
Word16 al [];
{

  Word16          wd1, wd2, spl;

  /* shift of rlt */
  rlt[2] = rlt[1];		
  rlt[1] = rlt[0];		

  wd1 = add (rlt[1], rlt[1]);
  wd1 = mult (al[1], wd1);
  wd2 = add (rlt[2], rlt[2]);
  wd2 = mult (al[2], wd2);
  spl = add (wd1, wd2);

  return (spl);
}
/* ..................... End of filtep() ..................... */


/*___________________________________________________________________________
                                                                            
    Function Name : filtez                                                  
                                                                            
    Purpose :                                                               
                                                                            
     .                  
                                                                            
    Inputs :                                                                
                                                                            
                                                                            
    Outputs :                                                               
                                                                            
     none                                                                   
                                                                            
    Return Value :                                                          
                                                                            
 ___________________________________________________________________________
*/
Word16 
filtez (dlt, bl)
Word16 dlt [];
Word16 bl [];
{
  Word16          szl, wd[7];
  Word16          i;

  for (i = 6, szl = 0; i > 0; i--)
  {
    wd[i] = add (dlt[i], dlt[i]);
    wd[i] = mult (wd[i], bl[i]);
    szl = add (szl, wd[i]);
  }

  return (szl);
}
/* ..................... End of filtez() ..................... */


/*___________________________________________________________________________
                                                                            
    Function Name : invqal                                                  
                                                                            
    Purpose :                                                               
                                                                            
     .                  
                                                                            
    Inputs :                                                                
                                                                            
                                                                            
    Outputs :                                                               
                                                                            
     none                                                                   
                                                                            
    Return Value :                                                          
                                                                            
 ___________________________________________________________________________
*/
Word16 
invqal (il, detl)
Word16 il;
Word16 detl;
{

  /* inverse quantizer 4 bits for encoder or decoder */
  static Word16   ril4[16] =
  {0, 7, 6, 5, 4, 3, 2, 1, 7, 6, 5, 4, 3, 2, 1, 0};
  static Word16   risil[16] =
  {0, -1, -1, -1, -1, -1, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0};
  static Word16   oq4[8] =
  {0, 150, 323, 530, 786, 1121, 1612, 2557};

  /* Local variables */
  Word16          ril, wd1, wd2;


  ril = shr (il, 2);
  wd1 = shl (oq4[ril4[ril]], 3);
  wd2 = (risil[ril] == 0) ? wd1 : negate (wd1);

  return (mult (detl, wd2));
}
/* ..................... End of invqal() ..................... */


/*___________________________________________________________________________
                                                                            
    Function Name : invqbl                                                  
                                                                            
    Purpose :