tomwalters@0: /*
tomwalters@0:   ftos.c        binary float-to-short conversion.
tomwalters@0:  --------
tomwalters@0: 
tomwalters@0: */
tomwalters@0: 
tomwalters@0: #include <stdio.h>
tomwalters@0: #include <math.h>
tomwalters@0: #include "options.h"
tomwalters@0: 
tomwalters@0: char applic[]     = "float to short data-type conversion." ;
tomwalters@0: 
tomwalters@0: static char *helpstr, *errstr ;
tomwalters@0: 
tomwalters@0: static Options option[] = {
tomwalters@0:     {   "help"      ,   "off"       ,  &helpstr     ,   "help"          ,  DEBUG     },
tomwalters@0:     {   "error"     ,   "off"       ,  &errstr      ,   "print overflow and quantization errors"  ,  VAL  },
tomwalters@0:    ( char * ) 0 } ;
tomwalters@0: 
tomwalters@0: 
tomwalters@0: #define MAX           32767.
tomwalters@0: #define MIN        ( -32767. )
tomwalters@0: 
tomwalters@0: main(argc, argv)
tomwalters@0: int   argc ;
tomwalters@0: char *argv[] ;
tomwalters@0: {
tomwalters@0:     FILE  *fp ;
tomwalters@0:     float  X  ;
tomwalters@0:     short  Y  ;
tomwalters@0:     int    i  ;
tomwalters@0:     float  min = MAX, fmin ;
tomwalters@0:     float  max = MIN, fmax ;
tomwalters@0:     float  quant, maxquant, sumquant=0 ;
tomwalters@0: 
tomwalters@0:     fp = openopts( option,argc,argv ) ;
tomwalters@0:     if ( !isoff( helpstr ) )
tomwalters@0: 	helpopts( helpstr, argv[0], applic, option ) ;
tomwalters@0: 
tomwalters@0:     if ( isoff( errstr ) ) {
tomwalters@0: 
tomwalters@0: 	while ( fread( &X, sizeof(float), 1, fp ) ) {
tomwalters@0: 	    Y = (short)X ;
tomwalters@0: 	    fwrite( &Y, sizeof(short), 1, stdout);
tomwalters@0: 	}
tomwalters@0:     }
tomwalters@0: 
tomwalters@0:     else {
tomwalters@0: 
tomwalters@0: 	for ( i = 0 ; fread( &X, sizeof(float), 1, fp ) ; i++ ) {
tomwalters@0: 	    if ( X > max ) max = X ;
tomwalters@0: 	    if ( X < min ) min = X ;
tomwalters@0: 	    quant = ( X - (int)X ) / (int)( 1 + X ) ;
tomwalters@0: 	    sumquant += quant ;
tomwalters@0: 	    if ( quant > maxquant ) maxquant = quant ;
tomwalters@0: 	    Y = (short)X ;
tomwalters@0: 	    fwrite( &Y, sizeof(short), 1, stdout);
tomwalters@0: 	}
tomwalters@0: 
tomwalters@0: 	if ( max > MAX || min < MIN ) {
tomwalters@0: 
tomwalters@0: 	    if ( max > MAX )  fmax = MAX / max ;
tomwalters@0: 	    if ( min < MIN )  fmin = MIN / min ;
tomwalters@0: 
tomwalters@0: 	    if ( fmax < fmin ) fprintf( stderr, "16-bit overflow  (scale down by a factor < %f\n", fmax ) ;
tomwalters@0: 	    else               fprintf( stderr, "16-bit underflow  (scale down by a factor < %f\n", fmin ) ;
tomwalters@0: 	}
tomwalters@0: 	fprintf( stderr, "max  quantization error = %f\n", maxquant   ) ;
tomwalters@0: 	fprintf( stderr, "mean quantization error = %f\n", sumquant/i ) ;
tomwalters@0:     }
tomwalters@0: 
tomwalters@0:     fclose(fp);
tomwalters@0:     exit(0);
tomwalters@0: }
tomwalters@0: 
tomwalters@0: