forked from sox_ng/sox_ng
60 lines
2.1 KiB
C
60 lines
2.1 KiB
C
/* libSoX effect: tremolo (c) 2007 robs@users.sourceforge.net
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*
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* This library is free software; you can redistribute it and/or modify it
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* under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation; either version 2.1 of the License, or (at
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* your option) any later version.
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*
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* This library is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
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* General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "sox_i.h"
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static int getopts(sox_effect_t * effp, int argc, char * * argv)
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{
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double speed, depth = 40;
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char dummy; /* To check for extraneous chars. */
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char offset[100];
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char * args[] = {0, "sine", "fmod", 0, 0, "25"};
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if (argc < 2 || argc > 3) return lsx_usage(effp);
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if (sscanf(argv[1], "%lf %c", &speed, &dummy) != 1 || speed < 0) {
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lsx_fail("speed `%s' must be a number >= 0", argv[1]);
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return SOX_EOF;
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}
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if ((argc > 2 && sscanf(argv[2], "%lf %c", &depth, &dummy) != 1) ||
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depth <= 0 || depth > 100) {
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lsx_fail("depth `%s' must be a positive number up to 100", argv[2]);
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return SOX_EOF;
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}
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args[0] = argv[0];
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args[3] = argv[1];
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sprintf(offset, "%g", 100 - depth / 2);
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args[4] = offset;
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return lsx_synth_effect_fn()->getopts(effp, (int)array_length(args), args);
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}
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sox_effect_handler_t const * lsx_tremolo_effect_fn(void)
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{
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static char const usage[] = "speed [depth]";
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static char const * const extra_usage[] = {
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"OPTION RANGE DEFAULT DESCRIPTION",
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"speed 0- none Frequency of the tremolo",
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"depth 0-100 40 Depth of the tremolo as a percentage",
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NULL
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};
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static sox_effect_handler_t handler;
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handler = *lsx_synth_effect_fn();
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handler.name = "tremolo";
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handler.usage = usage;
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handler.extra_usage = extra_usage;
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handler.getopts = getopts;
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return &handler;
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}
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