lowpassfilter.h

一个滤波器和一个音效处理程序 TI 的CCS 编译器编程。

/***********************************************************************
**  Global Varaibles that are Used for Security Voice System
***********************************************************************/
unsigned int  pSCarrierInd  = 0; /* carrier SINE index  */
int           pSCarrier     = 0; /* carrier SINE signal */
int           pSOut         = 0; /* securied voice output */
int           pMicPhIn      = 0; /* microphone input to slave AIC */

/* Filter Parameters: bo+b1z-1+b2z-2/(1+a1z-1+a2z-2) */
int           pb0       =  9597; /* b0 = 0.2929 */
int           pb1       =  -19194; /* b1 = -0.5858 hipass@4KHZ*/
//int           pb1       =  19194; /* b1 = 0.5858 lowpass@4KHZ*/
int           pb2       =  9597; /* b2 = 0.2929 */
int           pa1       =0; /* a1 =0 */
int           pa2       = 5623; /* a2 = 0.1716 */
/*int           pb0       =  7787;  b0 = 0.2376 */
/*int           pb1       = 15574;  b1 = 0.4753 */
/*int           pb2       =  7787;  b2 = 0.2376 */
/*int           pa1       = -7550;  a1 =-0.2304 */
/*int           pa2       =  5930;  a2 = 0.1810 */
   
int     pSInMx    = 0;     /* mixed signal = SIn*SCarrier */
int     pSInMxZ1  = 0;     /* mixed signal = SIn*Scarrier*z-1 */
int     pSInMxZ2  = 0;     /* mixed signal = SIn*SCarrier*z-2 */
int     pSOutZ1   = 0;     /* output during filtering*z-1 */
int     pSOutZ2   = 0;     /* output during filtering*z-2 */

long  int    pSOutTemp = 0;     /* output during filtering */
long  int    pSOutTemp1, pSOutTemp2, 
             pSOutTemp3, pSOutTemp4, pSOutTemp5;  
  
/***********************************************************************
**  Global Varaibles Used for TX DTMF Tone
***********************************************************************/
extern   int  ToneWave;
extern   unsigned int  SL_ADC;  /* slave AIC10 ADC input(microphone)*/
extern   int  f697[];           /* 697Hz sine table(16KHz SampleRate)*/
extern   int  f770[];           /* 770Hz sine table(16KHz S.R.)  */
extern   int  f852[];           /* 852Hz sine table(16KHz S.R.)  */
extern   int  f941[];           /* 941Hz sine table(16KHz S.R.)  */
extern   int  f1209[];          /* 1209Hz sine table(16KHz S.R.) */

/***********************************************************************
**  End of File -- SecurityVoice.h
***********************************************************************/