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/*
Calf Box, an open source musical instrument.
Copyright (C) 2010-2011 Krzysztof Foltman
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "config-api.h"
#include "dspmath.h"
#include "module.h"
#include "onepole-float.h"
#include <glib.h>
#include <malloc.h>
#include <math.h>
#include <memory.h>
#include <sndfile.h>
#include <stdio.h>
#include <stdlib.h>
#define MODULE_PARAMS limiter_params
struct limiter_params
{
float threshold;
float attack;
float release;
};
struct limiter_module
{
struct cbox_module module;
struct limiter_params *params, *old_params;
double cur_gain;
double atk_coeff, rel_coeff;
};
gboolean limiter_process_cmd(struct cbox_command_target *ct, struct cbox_command_target *fb, struct cbox_osc_command *cmd, GError **error)
{
struct limiter_module *m = (struct limiter_module *)ct->user_data;
EFFECT_PARAM("/threshold", "f", threshold, double, , -100, 12) else
EFFECT_PARAM("/attack", "f", attack, double, , 1, 1000) else
EFFECT_PARAM("/release", "f", release, double, , 1, 5000) else
if (!strcmp(cmd->command, "/status") && !strcmp(cmd->arg_types, ""))
{
if (!cbox_check_fb_channel(fb, cmd->command, error))
return FALSE;
return
cbox_execute_on(fb, NULL, "/threshold", "f", error, m->params->threshold) &&
cbox_execute_on(fb, NULL, "/attack", "f", error, m->params->attack) &&
cbox_execute_on(fb, NULL, "/release", "f", error, m->params->release) &&
CBOX_OBJECT_DEFAULT_STATUS(&m->module, fb, error);
}
else
return cbox_object_default_process_cmd(ct, fb, cmd, error);
return TRUE;
}
void limiter_process_event(struct cbox_module *module, const uint8_t *data, uint32_t len)
{
// struct limiter_module *m = module->user_data;
}
void limiter_process_block(struct cbox_module *module, cbox_sample_t **inputs, cbox_sample_t **outputs)
{
struct limiter_module *m = module->user_data;
struct limiter_params *mp = m->params;
if (m->params != m->old_params)
{
m->atk_coeff = 1 - exp(-1000.0 / (mp->attack * m->module.srate));
m->rel_coeff = 1 - exp(-1000.0 / (mp->release * m->module.srate));
// update calculated values
}
const double minval = pow(2.0, -110.0);
for (int i = 0; i < CBOX_BLOCK_SIZE; ++i)
{
float left = inputs[0][i], right = inputs[1][i];
float level = fabs(left);
if (fabs(right) > level)
level = fabs(right);
if (level < minval)
level = minval;
level = log(level);
float gain = 0.0;
if (level > mp->threshold * 0.11552)
gain = mp->threshold * 0.11552 - level;
// instantaneous attack + slow release
if (gain >= m->cur_gain)
m->cur_gain += m->rel_coeff * (gain - m->cur_gain);
else
m->cur_gain += m->atk_coeff * (gain - m->cur_gain);
gain = exp(m->cur_gain);
//if (gain < 1)
// printf("level = %f gain = %f\n", m->cur_level, gain);
outputs[0][i] = left * gain;
outputs[1][i] = right * gain;
}
}
MODULE_SIMPLE_DESTROY_FUNCTION(limiter)
MODULE_CREATE_FUNCTION(limiter)
{
static int inited = 0;
if (!inited)
{
inited = 1;
}
struct limiter_module *m = malloc(sizeof(struct limiter_module));
CALL_MODULE_INIT(m, 2, 2, limiter);
m->module.process_event = limiter_process_event;
m->module.process_block = limiter_process_block;
struct limiter_params *p = malloc(sizeof(struct limiter_params));
p->threshold = -1;
p->attack = 10.f;
p->release = 2000.f;
m->params = p;
m->old_params = NULL;
m->cur_gain = 0.f;
return &m->module;
}
struct cbox_module_keyrange_metadata limiter_keyranges[] = {
};
struct cbox_module_livecontroller_metadata limiter_controllers[] = {
};
DEFINE_MODULE(limiter, 0, 2)