#include <stdio.h>
#include <stdlib.h>
#include<sys/types.h>
#include<sys/stat.h>

/* ================================================================= */

#define FRAMESIZE  80
#define OBSDIM     25
#define OBSTYPE    454    /* MFCC_E_D_N */
#define SAMPRATE   8000.0
#define SAMPSIZE   sizeof(short)

/* --- Defines the ISOLET header structure --- */
/**/
typedef struct {
  short hdrsize;
  short version;
  short channels;
  short rate;
  int  nsamples;
  short endian;
} header;

header ISOLET;        /* The ISOLET database's header */
/* ================================================================= */

main(argc,argv)
int argc;
char *argv[];
{
  FILE  *fpi;
  FILE  *fpo;
  struct stat filerec;
  char  *infile;
  char  *outfile;
  short  *inbuf;
  short  *outbuf;
  short  *vcflag,x;
  float samprate;
  float srate=8000.0;    /* default sampling frequency */
  int   sampsize;
  int   framesize;
  int   numsamples;
  int   numobs;
  int   obsdim;
  short   osize=2;  /* Bytes per sample */
  short   otype=0;  /* Waveform type */
  int   isolet=0;
  int   oflag=0;
  int   rint=0;
  int   sflag=0;
  int   tflag=0;
  int   i,j,k,m,noheader=0;
  int GetNISTheader ();

  /* === parse the command line === */

  if (argc==1){
    printf("Usage: wav2htk [options] infile outfile\n\n");
    printf("Options                              Default\n");
    printf("-t     Add an ISOLET header            HTK\n");
    printf("-l     Add no header                   HTK\n\n");
    exit(1);
  }
    
  if(!scanargs(argc,argv,"adheader  l%- t%- infile!s outfile!s",&noheader,&isolet,&infile,&outfile))
   exit(1);


  /* === open output observation file === */

  fpi = fopen(infile,"rb");
  if (fpi == NULL)
  {
    printf("Error:  Unable to open input observation file (%s).\n",infile);
    exit(1);
  }

  /* === Read NIST header, compute number of samples in file === */

  numsamples = GetNISTheader(fpi,&srate);

  /* === open output  file === */

  fpo = fopen(outfile,"wb");
  if (fpo == NULL)
  {
    printf("Error:  Unable to create observation file (%s).\n",outfile);
    exit(1);
  }

  /* === allocate space for observations and read them === */
  inbuf = (short *) malloc(numsamples*sizeof(short));
  k=fread(inbuf,sizeof(short),numsamples,fpi);



  /* === write observation file header, if any === */
 
 if (!noheader) {

  if (isolet) {
    ISOLET.nsamples = numsamples;
    x= 1000000.0/(srate*0.25); 
    ISOLET.rate=x;
    ISOLET.hdrsize=8;
    ISOLET.version=1;
    ISOLET.channels=1;
    ISOLET.endian=0;
    fwrite(&ISOLET,1,sizeof(ISOLET),fpo);     
  }
  else {
    fwrite(&numsamples,sizeof(int),1,fpo);  /* number of observations */
    i = 10.0e+6/srate; 
    fwrite(&i,sizeof(int),1,fpo);       /* frame rate sec/frm (x100 nS) */
    fwrite(&osize,sizeof(short),1,fpo); /* bytes per feature */
    fwrite(&otype,sizeof(short),1,fpo); /* (htk) type of feature */
  }
 }

  /* === write output file === */

  fwrite(inbuf,numsamples,sizeof(short),fpo);

  fclose(fpo);
}



int GetNISTheader (fpin,srate)
FILE *fpin;
float *srate;
{
int num_samples,i,done=0;
char nst[40];


 fscanf(fpin,"%s",nst);   /* Check if it is a valid NIST file */
 if (strcmp(nst,"NIST_1A") == 0) {  /* proceed */
 

   done=0;
   while (!done) {

     fscanf(fpin,"%s",nst);  /* Get next sring */
     if ( strcmp(nst,"sample_count") == 0) {
            fscanf(fpin,"%s",nst);  /* Get the -i string */
	    fscanf(fpin,"%s",nst);  /* Get number of samples */
	    num_samples=atoi(nst);

	  }
     if ( strcmp(nst,"end_head") == 0) {
       printf("ERROR! Could not find NIST keywords in file..\n");
       exit(0);
     }
     if ( strcmp(nst,"sample_rate") == 0) {
       fscanf(fpin,"%s",nst); /* Skip the -i option */
       fscanf(fpin,"%s",nst); /* Get sampling frequency */
       *srate=(float) atoi(nst);  /* Get the Sampling frequency */
       if (*srate < 5000.0 || *srate > 21000.0){
	 printf("Sampling rate out of range: %f\n",*srate);
	 exit(1);}

       done=1;  /* exit */
     }
   }

  fseek(fpin,1024,0);  /* Skip the 1024 byte header */
 }
else {
  printf("ERROR! Invalid numbers in NIST headers: %s\n",nst);
  exit(0);
}
return(num_samples);
}