util.c

具有浮点指令的g.729语音压缩编码

/* ITU-T G.729 Software Package Release 2 (November 2006) */
/*
   ITU-T G.729 Annex C - Reference C code for floating point
                         implementation of G.729
                         Version 1.01 of 15.September.98
*/

/*
----------------------------------------------------------------------
                    COPYRIGHT NOTICE
----------------------------------------------------------------------
   ITU-T G.729 Annex C ANSI C source code
   Copyright (C) 1998, AT&T, France Telecom, NTT, University of
   Sherbrooke.  All rights reserved.

----------------------------------------------------------------------
*/

/*
 File : UTIL.C
 Used for the floating point version of both
 G.729 main body and G.729A
*/

/*****************************************************************************/
/* auxiliary functions                                                       */
/*****************************************************************************/

#include "typedef.h"
#include "version.h"
#ifdef VER_G729A
 #include "ld8a.h"
#else
 #include "ld8k.h"
#endif

/*-------------------------------------------------------------------*
 * Function  set zero()                                              *
 *           ~~~~~~~~~~                                              *
 * Set vector x[] to zero                                            *
 *-------------------------------------------------------------------*/

void set_zero(
  FLOAT  x[],       /* (o)    : vector to clear     */
  int L             /* (i)    : length of vector    */
)
{
   int i;

   for (i = 0; i < L; i++)
     x[i] = (F)0.0;

   return;
}

/*-------------------------------------------------------------------*
 * Function  copy:                                                   *
 *           ~~~~~                                                   *
 * Copy vector x[] to y[]                                            *
 *-------------------------------------------------------------------*/

void copy(
  FLOAT  x[],      /* (i)   : input vector   */
  FLOAT  y[],      /* (o)   : output vector  */
  int L            /* (i)   : vector length  */
)
{
   int i;

   for (i = 0; i < L; i++)
     y[i] = x[i];

   return;
}

/* Random generator  */

INT16 random_g729(void)
{
  static INT16 seed = 21845;

  seed = (INT16) (seed * 31821L + 13849L);

  return(seed);

}

/*-----------------------------------------------------------*
 * fwrite16 - writes a FLOAT array as a Short to a a file    *
 *-----------------------------------------------------------*/

void fwrite16(
 FLOAT *data,           /* input: inputdata */
 int length,          /* input: length of data array */
 FILE *fp               /* input: file pointer */
)
{
   int  i;
   INT16 sp16[L_FRAME];
   FLOAT temp;

   if (length > L_FRAME) {
      printf("error in fwrite16\n");
      exit(16);
   }

   for(i=0; i<length; i++)
    {
      /* round and convert to int  */
      temp = data[i];
      if (temp >= (F)0.0)
            temp += (F)0.5;
      else  temp -= (F)0.5;
      if (temp >  (F)32767.0 ) temp =  (F)32767.0;
      if (temp < (F)-32768.0 ) temp = (F)-32768.0;
      sp16[i] = (INT16) temp;
    }
    fwrite( sp16, sizeof(INT16), length, fp);
}