ec_main.cc

EC的语音编解码

// 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);
}