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/*
* July 5, 1991
* Copyright 1991 Lance Norskog And Sundry Contributors
* This source code is freely redistributable and may be used for
* any purpose. This copyright notice must be maintained.
* Lance Norskog And Sundry Contributors are not responsible for
* the consequences of using this software.
*/
/*
* Sound Tools text format file. Tom Littlejohn, March 93.
*
* Reads/writes sound files as text for use with fft and graph.
*
* June 28, 93: force output to mono.
*/
#include "st.h"
#include "libst.h"
/* Private data for dat file */
typedef struct dat {
double timevalue, deltat;
} *dat_t;
LONG roundoff(x)
double x;
{
if (x < 0.0) return(x - 0.5);
else return(x + 0.5);
}
void
datstartread(ft)
ft_t ft;
{
dat_t dat = (dat_t) ft->priv;
char inpstr[82];
char sc;
while (ft->info.rate == 0) {
fgets(inpstr,82,ft->fp);
sscanf(inpstr," %c",&sc);
if (sc != ';') fail("Cannot determine sample rate.");
sscanf(inpstr," ; Sample Rate %ld",&ft->info.rate);
}
/* size and style are really not necessary except to satisfy caller. */
ft->info.size = DOUBLE;
ft->info.style = SIGN2;
}
void
datstartwrite(ft)
ft_t ft;
{
dat_t dat = (dat_t) ft->priv;
double srate;
/*
if (ft->info.channels > 1)
fail("Cannot create .dat file with more than one channel.");
*/
ft->info.channels = 1;
dat->timevalue = 0.0;
srate = ft->info.rate;
dat->deltat = 1.0 / srate;
fprintf(ft->fp,"; Sample Rate %ld\015\n",ft->info.rate);
}
datread(ft, buf, nsamp)
ft_t ft;
LONG *buf, nsamp;
{
dat_t dat = (dat_t) ft->priv;
char inpstr[82];
double sampval;
int retc;
int done = 0;
char sc;
while (done < nsamp) {
do {
fgets(inpstr,82,ft->fp);
if (feof(ft->fp)) {
return done;
}
sscanf(inpstr," %c",&sc);
}
while(sc == ';'); /* eliminate comments */
retc = sscanf(inpstr,"%*s %lg",&sampval);
if (retc != 1) fail("Unable to read sample.");
*buf++ = roundoff(sampval * 2.147483648e9);
++done;
}
return done;
}
void
datwrite(ft, buf, nsamp)
ft_t ft;
LONG *buf, nsamp;
{
dat_t dat = (dat_t) ft->priv;
int done = 0;
double sampval;
while(done < nsamp) {
sampval = *buf++ ;
sampval = sampval / 2.147483648e9; /* normalize to approx 1.0 */
fprintf(ft->fp," %15.8g %15.8g \015\n",dat->timevalue,sampval);
dat->timevalue += dat->deltat;
done++;
}
return;
}
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