c_utils.cpp

rtp在linux下的实现

//	c_utils.cpp

//	utility functions for vad program

#include "c_utils.h"
#include <math.h>


S2byte 
sature16(S4byte data)
{
  if ( data > (S2byte)0x7fff )
    {
    	return (S2byte)MAX_16;
    }
  if ( data < (S2byte)0xffff8000 )
    {
    	return (S2byte)MIN_16;
    }
  return (S2byte)data; 
}

void
bqInit (t_biquad *bq, S2byte a0, S2byte a1, S2byte a2, S2byte b1, S2byte b2)
{
   bq->a0 = a0;
   bq->a11 = a1;
   bq->a12 = a2; 
   bq->negb11 = -b1;
   bq->negb12 = -b2;
   bq->dn_1 = 0;
   bq->dn_2 = 0;
}

void
bqProcess(t_biquad *bq, S2byte *datain, S2byte *dataout, int n) 
{
    int i;
    static S2byte prev = 1700;

	for (i = 0; i < n; i++)
	{
		/* do biquad processing */
	    
		dataout[i] = datain[i] - prev;
		prev = datain[i];
	}
    
}


void 
calcPower ( int length, U4byte *login, float *logout)	// formerly called log10_32()
{
    int i;

	for (i = 0; i < length; i++)
	{
		logout[i] = (float) (10 * log10(login[i]) - 10 * 9.332); 
	}
    
}