echocancel.h

一个滤波器和一个音效处理程序 TI 的CCS 编译器编程。

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/***********************************************************************
**  File Name:    EchoCancel.h
**  Part Number:  TLV320AIC10/11EVM-SW-00104
************************************************************************
**  Copyright (c) Texas Instruments, Inc. 2000
************************************************************************
**
**  Release History:
**     Version      Date          Engr          Description
**      1.00     10-11-2000     Wendy X Fang  Original Release
**
************************************************************************
**			
**  Function:
**      This is the head file for echo cancellation file -- EchoCancel.c,
**      which defines all of the variables and parameters.
**
***********************************************************************/

/***********************************************************************
**  Define Statements
***********************************************************************/
#define    Alpha         5    /* 2^Alpha=32 for 4ms window(8KHz S.R.) */
#define    FilterLength  32   /* FilterLength = 2^Alpha               */
#define    Mu          1024   /* adaption step = 0.015625             */
           
/***********************************************************************
**  Global Varaibles that are Used for Echo Cancellations
***********************************************************************/
unsigned  int  NCount = 0;    /* step counter */

int  h[FilterLength]   = {
                        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
                         };    /* adaptive filter coefficients */
int  SIn[FilterLength] = {
                        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
                         };    /* far end signal input array */

int      EchoResid    = 0;     /* echo estimation error or residual */
long int EchoEst      = 0;     /* estimated echo by adaptive filter */
long int PowerSIn     = 0;     /* far ebd signal power */
                            
/***********************************************************************
**  Global Varaibles Related to AIC10 RX/TX & defined by other Files
***********************************************************************/
extern unsigned int  SL_ADC;   /* near end input (echo) */
extern int  SOut;              /* output to far end */
extern int  ToneWave;          /* far end input & near end output */
                            
/***********************************************************************
**  End of File -- EchoCancel.h
***********************************************************************/