// file: ec_main.cc//// system include files//#include <stdio.h>#include <stdlib.h>#include <memory.h>#include <math.h>// local include files//#include "ec.h"#include "ec_constants.h"//-----------------------------------------------------------------------------//// program: ec_main.cc// synopsis: echoc.exe// descr: removes echo from a stero file (see below)// example: ec.exe  < foo_stereo_echo.raw >  foo_stereo_clean.raw//// options: none//// arguments: none//// note://  this program is a fairly hardcoded implementation of a standard//  echo canceller. stdin and stdout are used to I/O. The input signal//  is assumed to be of the following form:////   - interleaved 16-bit two-channel samples//   - the first two bytes correspond to the reference signal//   - the second two bytes correspond to the signal plus echo (channel 1)////  the output signal consists of the echo cancelled channel 1 data.////-----------------------------------------------------------------------------main(int argc) {  //---------------------------------------------------------------------------  //  // process the command line arguments  //  //---------------------------------------------------------------------------  // check the number of arguments  //  if (argc != NARGS) {    fprintf(stderr, "usage: ec.exe < input_file.raw >  output_file.raw\n");    return(1);  }  // declare an echo canceller object for the reference far-end speech and  // the near-end speech  //  Echo_canceller ec_ref;  Echo_canceller ec_near;    // initialize the echo canceller  //  ec_ref.init_cc(DEFAULT_GAMMA, DEFAULT_N, DEFAULT_M, DEFAULT_BETA1,		 DEFAULT_SIGMA_LY, DEFAULT_SIGMA_LU,		 DEFAULT_ALPHA_ST, DEFAULT_ALPHA_YT, DEFAULT_CUTOFF,		 DEFAULT_HANGT, DEFAULT_SUPPR, DEFAULT_TAU);  ec_near.init_cc(DEFAULT_GAMMA, DEFAULT_N, DEFAULT_M, DEFAULT_BETA1,		  DEFAULT_SIGMA_LY, DEFAULT_SIGMA_LU,		  DEFAULT_ALPHA_ST, DEFAULT_ALPHA_YT, DEFAULT_CUTOFF,		  DEFAULT_HANGT, DEFAULT_SUPPR, DEFAULT_TAU);    //---------------------------------------------------------------------------  //  // process data  //  //---------------------------------------------------------------------------    // main echo cancellation loop  //  short int sig_in[NCHAN];  short int sig_out[NCHAN];    while (fread(sig_in, NCHAN*sizeof(short int), (int)1, stdin) >	 (unsigned int)0) {    // split the data    //    double ref = AMPL_SCALE_1 * (double)sig_in[C_R];    double sig = AMPL_SCALE_1 * (double)sig_in[C_E];        // process the data    //    sig_out[C_E] = ec_ref.clip_cc(ec_ref.process_cc(ref, sig));    sig_out[C_R] = ec_near.clip_cc(ec_near.process_cc(sig, ref));    // write the output data    //    fwrite(&sig_out, NCHAN*sizeof(short int), (int)1, stdout);  }  // exit gracefully  //  return(0);}