basic_op.c

ITU-T G.729 Source code(已经验证过的)

 |   Return Value :                                                          |
 |                                                                           |
 |    var_out                                                                |
 |             16 bit short signed integer (Word16) whose value falls in the |
 |             range : 0xffff 8000 <= var_out <= 0x0000 7fff.                |
 |___________________________________________________________________________|
*/

Word16 negate(Word16 var1)
  {
   Word16 var_out;

   var_out = (var1 == MIN_16) ? MAX_16 : -var1;
   return(var_out);
  }


/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : extract_h                                               |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Return the 16 MSB 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_h(Word32 L_var1)
  {
   Word16 var_out;

   var_out = (Word16) (L_var1 >> 16);
   return(var_out);
  }

/*___________________________________________________________________________
 |                                                                           |
 |   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(Word32 L_var1)
  {
   Word16 var_out;

   var_out = (Word16) L_var1;
   return(var_out);
  }


/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : round                                                   |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Round the lower 16 bits of the 32 bit input number into its MS 16 bits  |
 |   with saturation. Shift the resulting bits right by 16 and return the 16 |
 |   bit number:                                                             |
 |               round(L_var1) = extract_h(L_add(L_var1,32768))              |
 |                                                                           |
 |   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 round(Word32 L_var1)
  {
   Word16 var_out;
   Word32 L_arrondi;

   L_arrondi = L_add(L_var1, (Word32)0x00008000);
   var_out = extract_h(L_arrondi);
   return(var_out);
  }


/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_mac                                                   |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Multiply var1 by var2 and shift the result left by 1. Add the 32 bit    |
 |   result to L_var3 with saturation, return a 32 bit result:               |
 |        L_mac(L_var3,var1,var2) = L_add(L_var3,(L_mult(var1,var2)).        |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    L_var3   32 bit long signed integer (Word32) whose value falls in the  |
 |             range : 0x8000 0000 <= L_var3 <= 0x7fff ffff.                 |
 |                                                                           |
 |    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 :                                                          |
 |                                                                           |
 |    L_var_out                                                              |
 |             32 bit long signed integer (Word32) whose value falls in the  |
 |             range : 0x8000 0000 <= L_var_out <= 0x7fff ffff.              |
 |___________________________________________________________________________|
*/

Word32 L_mac(Word32 L_var3, Word16 var1, Word16 var2)
  {
   Word32 L_var_out;
   Word32 L_produit;

   L_produit = L_mult(var1,var2);
   L_var_out = L_add(L_var3,L_produit);
   return(L_var_out);
  }


/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_msu                                                   |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Multiply var1 by var2 and shift the result left by 1. Subtract the 32   |
 |   bit result to L_var3 with saturation, return a 32 bit result:           |
 |        L_msu(L_var3,var1,var2) = L_sub(L_var3,(L_mult(var1,var2)).        |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    L_var3   32 bit long signed integer (Word32) whose value falls in the  |
 |             range : 0x8000 0000 <= L_var3 <= 0x7fff ffff.                 |
 |                                                                           |
 |    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 :                                                          |
 |                                                                           |
 |    L_var_out                                                              |
 |             32 bit long signed integer (Word32) whose value falls in the  |
 |             range : 0x8000 0000 <= L_var_out <= 0x7fff ffff.              |
 |___________________________________________________________________________|
*/

Word32 L_msu(Word32 L_var3, Word16 var1, Word16 var2)
  {
   Word32 L_var_out;
   Word32 L_produit;

   L_produit = L_mult(var1,var2);
   L_var_out = L_sub(L_var3,L_produit);
   return(L_var_out);
  }


/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_macNs                                                 |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Multiply var1 by var2 and shift the result left by 1. Add the 32 bit    |
 |   result to L_var3 without saturation, return a 32 bit result. Generate   |
 |   carry and overflow values :                                             |
 |        L_macNs(L_var3,var1,var2) = L_add_c(L_var3,(L_mult(var1,var2)).    |
 |                                                                           |
 |   Complexity weight : 1                                                   |