ref: f5afb3930673306a62ae50948af973c66331b002
dir: /src/tremolo.c/
/*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, write to the Free Software Foundation,
* Fifth Floor, 51 Franklin Street, Boston, MA 02111-1301, USA.
*/
/* Effect: tremolo (c) 2007 robs@users.sourceforge.net */
#include "synth.h"
static int getopts(eff_t effp, int n, char * * argv)
{
double speed, depth = 40;
char dummy; /* To check for extraneous chars. */
char offset[100];
char * synth_args[] = {"sine", "fmod", 0, 0};
if (n < 1 || n > 2 ||
sscanf(argv[0], "%lf %c", &speed, &dummy) != 1 || speed < 0 ||
(n > 1 && sscanf(argv[1], "%lf %c", &depth, &dummy) != 1) ||
depth <= 0 || depth > 100) {
sox_fail(effp->h->usage);
return SOX_EOF;
}
synth_args[2] = argv[0];
sprintf(offset, "%g", 100 - depth / 2);
synth_args[3] = offset;
return sox_synth_getopts(effp, array_length(synth_args), synth_args);
}
sox_effect_t const * sox_tremolo_effect_fn(void)
{
static sox_effect_t driver = {
"tremolo", "Usage: tremolo speed_Hz [depth_percent];", SOX_EFF_MCHAN,
getopts, sox_synth_start, sox_synth_flow, 0, 0, 0,
};
return &driver;
}