/**************************************************************************/
/*                           File: snr_prms.h                             */
/**************************************************************************/
/* Project: Computing SNR of a given signal      Class: EE 8993 Spring 96 */
/* Author: Neeraj Deshmukh                       Date: February 19, 1996  */
/**************************************************************************/

/*========================================================================
  This file declares the various parameters and the SNR_Detector class
  for the signal-to-noise computation of any given signal
  ========================================================================*/

/*------------------------------------------------------------------------
  make sure definitions are only made once
  ------------------------------------------------------------------------*/
#ifndef __ISIP_SNR_PRMS
#define __ISIP_SNR_PRMS

/*------------------------------------------------------------------------
  system and ISIP include files
  ------------------------------------------------------------------------*/
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <math.h>
#include <math/integral/integral.h>

/*------------------------------------------------------------------------
  declaration of global data types
  ------------------------------------------------------------------------*/
typedef char *String;

/*------------------------------------------------------------------------
  declaration of global constants
  ------------------------------------------------------------------------*/
#define WINDOW_DURATION           0.03             // 30 ms window
#define FRAME_DURATION            0.02             // 20 ms frame
#define SAMPLE_FREQUENCY          8000             // sampling rate
#define PREEMPHASIS               0.95             // pre-emphasis coef
#define MAX_FRAMES                1500

#define SAMPLE_SCALE_FACTOR       3.05185e-05
#define DB_CONSTANT               10
#define PI                        3.1415927

// intervals for cumulative energy distribution
//
#define NUM_BINS                  10000
#define NOMINAL_SIG_NOISE         0.85
#define NOMINAL_NOISE             0.15

/*------------------------------------------------------------------------
  declaration of non-method static functions
  ------------------------------------------------------------------------*/
extern FILE   *open_file_cc (String name, String mode);

/*------------------------------------------------------------------------
  declaration of SNR_Detector class
  ------------------------------------------------------------------------*/
class SNR_Detector
{
  // members
  //
protected:
  
  /*----------------------
    signal parameters data
    ----------------------*/
  int_2  *signal_frame_d;         // signal frame
  int_2  frame_dur_d;             // duration of frame in samples
  float  *ham_window_d;           // hamming window
  int_2  window_dur_d;            // duration of window in samples
  int_2  win_offset_d;            // offset between frame and window
  int_2  frame_offset_d;          // offset between frame and window
  
  /*----------------------
    signal processing data
    ----------------------*/
  float  *energy_var_d;           // energy variance array

  // methods
  //
public:
  
  /*--------------------------
    constructors & destructors
    --------------------------*/
  SNR_Detector ();
  ~SNR_Detector ();

  /*---------------------------
    main SNR computing function
    ---------------------------*/
  void compute_snr_cc ();

private:
  
  /*----------------------------
    internal calculation methods
    ----------------------------*/
  void  ham_window_cc ();               // create hamming window
  float compute_energy_cc ();           // compute the energy density
  float cumul_energy_dist_cc (int num_frames_l);
};

#endif