ref: 455880cdb3e12f68ba06b025898442f0917a8483
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 "sox_i.h"
static int getopts(sox_effect_t * effp, int n, char * * argv)
{
double speed, depth = 40;
char dummy; /* To check for extraneous chars. */
char offset[100];
char * 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)
return sox_usage(effp);
args[2] = argv[0];
sprintf(offset, "%g", 100 - depth / 2);
args[3] = offset;
return sox_synth_effect_fn()->getopts(effp, array_length(args), args);
}
sox_effect_handler_t const * sox_tremolo_effect_fn(void)
{
static sox_effect_handler_t handler;
handler = *sox_synth_effect_fn();
handler.name = "tremolo";
handler.usage = "speed_Hz [depth_percent]";
handler.getopts = getopts;
return &handler;
}