ref: 419169928d972e6090d186e776819553f2c05d9e
dir: /cut.c/
/*
* 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 cut effect file.
*
* Pull loop #n from a looped sound file.
* Not finished, don't use it yet.
*/
#include <math.h>
#include "st.h"
/* Private data for SKEL file */
typedef struct cutstuff {
int which; /* Loop # to pull */
int where; /* current sample # */
ULONG start; /* first wanted sample */
ULONG end; /* last wanted sample + 1 */
} *cut_t;
/*
* Process options
*/
void cut_getopts(effp, n, argv)
eff_t effp;
int n;
char **argv;
{
cut_t cut = (cut_t) effp->priv;
/* parse it */
cut->which = 0; /* for now */
}
/*
* Prepare processing.
*/
void cut_start(effp)
eff_t effp;
{
cut_t cut = (cut_t) effp->priv;
/* nothing to do */
cut->where = 0;
cut->start = effp->loops[0].start;
cut->end = effp->loops[0].start + effp->loops[0].length;
}
/*
* Processed signed long samples from ibuf to obuf.
* Return number of samples processed.
*/
void cut_flow(effp, ibuf, obuf, isamp, osamp)
eff_t effp;
LONG *ibuf, *obuf;
int *isamp, *osamp;
{
cut_t cut = (cut_t) effp->priv;
int len, done;
len = ((*isamp > *osamp) ? *osamp : *isamp);
if ((cut->where + len <= cut->start) ||
(cut->where >= cut->end)) {
*isamp = len;
*osamp = 0;
cut->where += len;
return;
}
*isamp = len; /* We will have processed all inputs */
if (cut->where < cut->start) {
/* skip */
ibuf += cut->start - cut->where;
len -= cut->start - cut->where;
}
if (cut->where + len >= cut->end) {
/* shorten */
len = cut->end - cut->where;
}
for(done = 0; done < len; done++) {
*obuf++ = *ibuf++;
}
*osamp = len;
}
/*
* Drain out remaining samples if the effect generates any.
*/
void cut_drain(effp, obuf, osamp)
eff_t effp;
LONG *obuf;
int *osamp;
{
*osamp = 0;
}
/*
* Do anything required when you stop reading samples.
* (free allocated memory, etc.)
*/
void cut_stop(effp)
eff_t effp;
{
/* nothing to do */
}