g729ev_main_oper_32b.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 "stl.h"
#include "G729EV_MAIN_OPER_32B.h"


/*___________________________________________________________________________
 |                                                                           |
 |  This file contains operations in double precision.                       |
 |  These operations are not standard double precision operations.           |
 |  They are used where single precision is not enough but the full 32 bits  |
 |  precision is not necessary. For example, the function Div_32() has a     |
 |  24 bits precision which is enough for our purposes.                      |
 |                                                                           |
 |  The double precision numbers use a special representation:               |
 |                                                                           |
 |     L_32 = hi<<16 + lo<<1                                                 |
 |                                                                           |
 |  L_32 is a 32 bit integer.                                                |
 |  hi and lo are 16 bit signed integers.                                    |
 |  As the low part also contains the sign, this allows fast multiplication. |
 |                                                                           |
 |      0x8000 0000 <= L_32 <= 0x7fff fffe.                                  |
 |                                                                           |
 |  We will use DPF (Double Precision Format )in this file to specify        |
 |  this special format.                                                     |
 |___________________________________________________________________________|
*/

/*___________________________________________________________________________
 |                                                                           |
 |  Function L_Extract()                                                     |
 |                                                                           |
 |  Extract from a 32 bit integer two 16 bit DPF.                            |
 |                                                                           |
 |  Arguments:                                                               |
 |                                                                           |
 |   L_32      : 32 bit integer.                                             |
 |               0x8000 0000 <= L_32 <= 0x7fff ffff.                         |
 |   hi        : b16 to b31 of L_32                                          |
 |   lo        : (L_32 - hi<<16)>>1                                          |
 |___________________________________________________________________________|
*/

void L_Extract(Word32 L_32, Word16 * hi, Word16 * lo)
{
  *hi = extract_h(L_32);
  *lo = extract_l(L_msu(L_shr(L_32, 1), *hi, 16384)); /* lo = L_32>>1   */
  return;
}

/*___________________________________________________________________________
 |                                                                           |
 |  Function L_Comp()                                                        |
 |                                                                           |
 |  Compose from two 16 bit DPF a 32 bit integer.                            |
 |                                                                           |
 |     L_32 = hi<<16 + lo<<1                                                 |
 |                                                                           |
 |  Arguments:                                                               |
 |                                                                           |
 |   hi        msb                                                           |
 |   lo        lsf (with sign)                                               |
 |                                                                           |
 |   Return Value :                                                          |
 |                                                                           |
 |             32 bit long signed integer (Word32) whose value falls in the  |
 |             range : 0x8000 0000 <= L_32 <= 0x7fff fff0.                   |
 |                                                                           |
 |___________________________________________________________________________|
*/

Word32 L_Comp(Word16 hi, Word16 lo)
{
  Word32    L_32;

  L_32 = L_deposit_h(hi);
  return (L_mac(L_32, lo, 1));  /* = hi<<16 + lo<<1 */
}

/*___________________________________________________________________________
 | Function Mpy_32()                                                         |
 |                                                                           |
 |   Multiply two 32 bit integers (DPF). The result is divided by 2**31      |
 |                                                                           |
 |   L_32 = (hi1*hi2)<<1 + ( (hi1*lo2)>>15 + (lo1*hi2)>>15 )<<1              |
 |                                                                           |
 |   This operation can also be viewed as the multiplication of two Q31      |
 |   number and the result is also in Q31.                                   |
 |                                                                           |
 | Arguments:                                                                |
 |                                                                           |
 |  hi1         hi part of first number                                      |
 |  lo1         lo part of first number                                      |
 |  hi2         hi part of second number                                     |
 |  lo2         lo part of second number                                     |
 |                                                                           |
 |___________________________________________________________________________|
*/

Word32 Mpy_32(Word16 hi1, Word16 lo1, Word16 hi2, Word16 lo2)
{
  Word32    L_32;

  L_32 = L_mult(hi1, hi2);
  L_32 = L_mac(L_32, mult(hi1, lo2), 1);
  L_32 = L_mac(L_32, mult(lo1, hi2), 1);

  return (L_32);
}

/*___________________________________________________________________________
 | Function Mpy_32_16()                                                      |
 |                                                                           |
 |   Multiply a 16 bit integer by a 32 bit (DPF). The result is divided      |
 |   by 2**15                                                                |
 |                                                                           |
 |   This operation can also be viewed as the multiplication of a Q31        |
 |   number by a Q15 number, the result is in Q31.                           |
 |                                                                           |
 |   L_32 = (hi1*lo2)<<1 + ((lo1*lo2)>>15)<<1                                |
 |                                                                           |
 | Arguments:                                                                |
 |                                                                           |
 |  hi          hi part of 32 bit number.                                    |
 |  lo          lo part of 32 bit number.                                    |
 |  n           16 bit number.                                               |
 |                                                                           |
 |___________________________________________________________________________|
*/

Word32 Mpy_32_16(Word16 hi, Word16 lo, Word16 n)
{
  Word32    L_32;

  L_32 = L_mult(hi, n);
  L_32 = L_mac(L_32, mult(lo, n), 1);

  return (L_32);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : Div_32                                                  |
 |                                                                           |
 |   Purpose :                                                               |
 |             Fractional integer division of two 32 bit numbers.            |
 |             L_num / L_denom.                                              |
 |             L_num and L_denom must be positive and L_num < L_denom.       |
 |             L_denom = denom_hi<<16 + denom_lo<<1                          |