operg722.c

ITU-T G.191中包含的G.722语音压缩编解码程序

/*                                                   Version: 2.00 - 01.Jul.95
  ============================================================================

                          U    U   GGG    SSSS  TTTTT
                          U    U  G       S       T
                          U    U  G  GG   SSSS    T
                          U    U  G   G       S   T
                           UUU     GG     SSS     T

                   ========================================
                    ITU-T - USER'S GROUP ON SOFTWARE TOOLS
                   ========================================


       =============================================================
       COPYRIGHT NOTE: This source code, and all of its derivations,
       is subject to the "ITU-T General Public License". Please have
       it  read  in    the  distribution  disk,   or  in  the  ITU-T
       Recommendation G.191 on "SOFTWARE TOOLS FOR SPEECH AND  AUDIO
       CODING STANDARDS". 
       ** This code has  (C) Copyright by CNET Lannion A TSS/CMC **
       =============================================================


MODULE:         G722.C 7kHz ADPCM AT 64 KBIT/S MODULE ENCODER AND 
                DECODER BASIC OPERATORS

ORIGINAL BY:
    J-P PETIT 
    CNET - Centre Lannion A
    LAA-TSS                         Tel: [phone]
    Route de Tregastel - BP 40      Fax: [phone]
    F-22301 Lannion CEDEX           Email: [e-mail]
    FRANCE
    
   History:
   14.Mar.95    v1.0    Released for use ITU-T UGST software package Tool
                        based on the CNET's 07/01/90 version 2.00
   01.Jul.95    v2.0    Changed function declarations to work with 
                        many compilers; reformated <[e-mail]>
  ============================================================================
*/

#include <stdio.h>
#include <stdlib.h>
#include "operg722.h"

/* DEFINITION FOR SMART PROTOTYPES */
#ifndef ARGS
#if defined(MSDOS) || defined(__MSDOS__) || defined(__STDC__) || defined(VMS) || defined (__CYGWIN__) || defined (_MSC_VER)
#define ARGS(x) x
#else /* Unix: no parameters in prototype! */
#define ARGS(x) ()
#endif
#endif

/* Local function prototypes */
Word16 sature ARGS((Word32 L_var1));
Word16 extract_l ARGS((Word32 L_var1));
Word16 add ARGS((Word16 var1, Word16 var2));
Word16 sub ARGS((Word16 var1, Word16 var2));
Word16 shl ARGS((Word16 var1, Word16 var2));
Word16 shr ARGS((Word16 var1, Word16 var2));
Word16 mult ARGS((Word16 var1, Word16 var2));
Word16 negate ARGS((Word16 var1));
Word32 L_add ARGS((Word32 L_var1, Word32 L_var2));
Word32 L_shr ARGS((Word32 L_var1, Word16 var2));
Word32 L_shl ARGS((Word32 L_var1, Word16 var2));


/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : sature                                                  |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |    Limit the 32 bit input to the range of a 16 bit word.                  |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    L_var1                                                                 |
 |             32 bit long signed integer (Word32) whose value falls in the  |
 |             range : 0x8000 0000 <= L_var1 <= 0x7fff ffff.                 |
 |                                                                           |
 |   Outputs :                                                               |
 |                                                                           |
 |    none                                                                   |
 |                                                                           |
 |   Return Value :                                                          |
 |                                                                           |
 |    var_out                                                                |
 |             16 bit short signed integer (Word16) whose value falls in the |
 |             range : 0xffff 8000 <= var_out <= 0x0000 7fff.                |
 |___________________________________________________________________________|
*/
Word16 
sature (L_var1)
Word32 L_var1;
{
  Word16          var_out;

  if (L_var1 > 0X00007fffL)
  {
    var_out = MAX_16;
  }
  else
  {
    if (L_var1 < (Word32) 0xffff8000L)
    {
      var_out = MIN_16;
    }
    else
    {
      var_out = extract_l (L_var1);
    }
  }
  return (var_out);
}
/* ....................... end of sature() ............................ */

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : extract_l                                               |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Return the 16 LSB of L_var1.                                            |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    L_var1                                                                 |
 |             32 bit long signed integer (Word32 ) whose value falls in the |
 |             range : 0x8000 0000 <= L_var1 <= 0x7fff ffff.                 |
 |                                                                           |
 |   Outputs :                                                               |
 |                                                                           |
 |    none                                                                   |
 |                                                                           |
 |   Return Value :                                                          |
 |                                                                           |
 |    var_out                                                                |
 |             16 bit short signed integer (Word16) whose value falls in the |
 |             range : 0xffff 8000 <= var_out <= 0x0000 7fff.                |
 |___________________________________________________________________________|
 */

Word16 
extract_l (L_var1)
Word32 L_var1;
{
  Word16          var_out;

  var_out = (Word16) L_var1;
  return (var_out);
}
/* ....................... end of extract_l() ............................ */


/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : add                                                     |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |    Performs the addition (var1+var2) with overflow control and saturation;|
 |    the 16 bit result is set at +32767 when overflow occurs or at -32768   |
 |    when underflow occurs.                                                 |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    var1                                                                   |
 |             16 bit short signed integer (Word16) whose value falls in the |
 |             range : 0xffff 8000 <= var1 <= 0x0000 7fff.                   |
 |                                                                           |
 |    var2                                                                   |
 |             16 bit short signed integer (Word16) whose value falls in the |
 |             range : 0xffff 8000 <= var1 <= 0x0000 7fff.                   |
 |                                                                           |
 |   Outputs :                                                               |
 |                                                                           |
 |    none                                                                   |
 |                                                                           |
 |   Return Value :                                                          |
 |                                                                           |
 |    var_out                                                                |
 |             16 bit short signed integer (Word16) whose value falls in the |
 |             range : 0xffff 8000 <= var_out <= 0x0000 7fff.                |
 |___________________________________________________________________________|
 */

Word16 
add (var1, var2)
Word16 var1;
Word16 var2;
{
  Word16          var_out;
  Word32          L_somme;

  L_somme = (Word32) var1 + (Word32) var2;
  var_out = sature (L_somme);
  return (var_out);
}
/* ....................... end of add() ............................ */


/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : sub                                                     |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |    Performs the subtraction (var1+var2) with overflow control and satu-   |
 |    ration; the 16 bit result is set at +32767 when overflow occurs or at  |
 |    -32768 when underflow occurs.                                          |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    var1                                                                   |
 |             16 bit short signed integer (Word16) whose value falls in the |
 |             range : 0xffff 8000 <= var1 <= 0x0000 7fff.                   |
 |                                                                           |
 |    var2                                                                   |