RetroArch/libretro-common/audio/dsp_filters/reverb.c
2023-02-23 13:15:14 +01:00

318 lines
8.8 KiB
C

/* Copyright (C) 2010-2020 The RetroArch team
*
* ---------------------------------------------------------------------------------------
* The following license statement only applies to this file (reverb.c).
* ---------------------------------------------------------------------------------------
*
* Permission is hereby granted, free of charge,
* to any person obtaining a copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <retro_inline.h>
#include <boolean.h>
#include <libretro_dspfilter.h>
struct comb
{
float *buffer;
unsigned bufsize;
unsigned bufidx;
float feedback;
float filterstore;
float damp1, damp2;
};
struct allpass
{
float *buffer;
float feedback;
unsigned bufsize;
unsigned bufidx;
};
static INLINE float comb_process(struct comb *c, float input)
{
float output = c->buffer[c->bufidx];
c->filterstore = (output * c->damp2) + (c->filterstore * c->damp1);
c->buffer[c->bufidx] = input + (c->filterstore * c->feedback);
c->bufidx++;
if (c->bufidx >= c->bufsize)
c->bufidx = 0;
return output;
}
static INLINE float allpass_process(struct allpass *a, float input)
{
float bufout = a->buffer[a->bufidx];
float output = -input + bufout;
a->buffer[a->bufidx] = input + bufout * a->feedback;
a->bufidx++;
if (a->bufidx >= a->bufsize)
a->bufidx = 0;
return output;
}
#define NUMCOMBS 8
#define NUMALLPASSES 4
static const float muted = 0.0f;
static const float fixedgain = 0.015f;
static const float scalewet = 3.0f;
static const float scaledry = 2.0f;
static const float scaledamp = 0.4f;
static const float scaleroom = 0.28f;
static const float offsetroom = 0.7f;
static const float initialroom = 0.5f;
static const float initialdamp = 0.5f;
static const float initialwet = 1.0f / 3.0f;
static const float initialdry = 0.0f;
static const float initialwidth = 1.0f;
static const float initialmode = 0.0f;
static const float freezemode = 0.5f;
struct revmodel
{
struct comb combL[NUMCOMBS];
struct allpass allpassL[NUMALLPASSES];
float *bufcomb[NUMCOMBS];
float *bufallpass[NUMALLPASSES];
float gain;
float roomsize, roomsize1;
float damp, damp1;
float wet, wet1, wet2;
float dry;
float width;
float mode;
};
static float revmodel_process(struct revmodel *rev, float in)
{
int i;
float mono_out = 0.0f;
float mono_in = in;
float input = mono_in * rev->gain;
for (i = 0; i < NUMCOMBS; i++)
mono_out += comb_process(&rev->combL[i], input);
for (i = 0; i < NUMALLPASSES; i++)
mono_out = allpass_process(&rev->allpassL[i], mono_out);
return mono_in * rev->dry + mono_out * rev->wet1;
}
static void revmodel_update(struct revmodel *rev)
{
int i;
rev->wet1 = rev->wet * (rev->width / 2.0f + 0.5f);
if (rev->mode >= freezemode)
{
rev->roomsize1 = 1.0f;
rev->damp1 = 0.0f;
rev->gain = muted;
}
else
{
rev->roomsize1 = rev->roomsize;
rev->damp1 = rev->damp;
rev->gain = fixedgain;
}
for (i = 0; i < NUMCOMBS; i++)
{
rev->combL[i].feedback = rev->roomsize1;
rev->combL[i].damp1 = rev->damp1;
rev->combL[i].damp2 = 1.0f - rev->damp1;
}
}
static void revmodel_setroomsize(struct revmodel *rev, float value)
{
rev->roomsize = value * scaleroom + offsetroom;
revmodel_update(rev);
}
static void revmodel_setdamp(struct revmodel *rev, float value)
{
rev->damp = value * scaledamp;
revmodel_update(rev);
}
static void revmodel_setwet(struct revmodel *rev, float value)
{
rev->wet = value * scalewet;
revmodel_update(rev);
}
static void revmodel_setdry(struct revmodel *rev, float value)
{
rev->dry = value * scaledry;
revmodel_update(rev);
}
static void revmodel_setwidth(struct revmodel *rev, float value)
{
rev->width = value;
revmodel_update(rev);
}
static void revmodel_setmode(struct revmodel *rev, float value)
{
rev->mode = value;
revmodel_update(rev);
}
static void revmodel_init(struct revmodel *rev, int srate, bool right)
{
unsigned c;
static const int comb_lengths[8] = { 1116, 1188, 1277, 1356, 1422, 1491, 1557, 1617 };
static const int allpass_lengths[4] = { 225, 341, 441, 556 };
double r = srate * (1 / 44100.0);
int stereosep = right ? 23 : 0;
for (c = 0; c < NUMCOMBS; ++c)
{
rev->bufcomb[c] = malloc(r * comb_lengths[c] + stereosep * sizeof(float));
rev->combL[c].buffer = rev->bufcomb[c];
memset(rev->combL[c].buffer, 0, r * comb_lengths[c] + stereosep * sizeof(float));
rev->combL[c].bufsize = r * comb_lengths[c] + stereosep;
}
for (c = 0; c < NUMALLPASSES; ++c)
{
rev->bufallpass[c] = malloc(r * allpass_lengths[c] + stereosep * sizeof(float));
rev->allpassL[c].buffer = rev->bufallpass[c];
memset(rev->allpassL[c].buffer, 0, r * allpass_lengths[c] + stereosep * sizeof(float));
rev->allpassL[c].bufsize = r * allpass_lengths[c] + stereosep;
rev->allpassL[c].feedback = 0.5f;
}
revmodel_setwet(rev, initialwet);
revmodel_setroomsize(rev, initialroom);
revmodel_setdry(rev, initialdry);
revmodel_setdamp(rev, initialdamp);
revmodel_setwidth(rev, initialwidth);
revmodel_setmode(rev, initialmode);
}
struct reverb_data
{
struct revmodel left, right;
};
static void reverb_free(void *data)
{
unsigned i;
struct reverb_data *rev = (struct reverb_data*)data;
for (i = 0; i < NUMCOMBS; i++)
{
free(rev->left.bufcomb[i]);
free(rev->right.bufcomb[i]);
}
for (i = 0; i < NUMALLPASSES; i++)
{
free(rev->left.bufallpass[i]);
free(rev->right.bufallpass[i]);
}
free(data);
}
static void reverb_process(void *data, struct dspfilter_output *output,
const struct dspfilter_input *input)
{
unsigned i;
float *out;
struct reverb_data *rev = (struct reverb_data*)data;
output->samples = input->samples;
output->frames = input->frames;
out = output->samples;
for (i = 0; i < input->frames; i++, out += 2)
{
float in[2] = { out[0], out[1] };
out[0] = revmodel_process(&rev->left, in[0]);
out[1] = revmodel_process(&rev->right, in[1]);
}
}
static void *reverb_init(const struct dspfilter_info *info,
const struct dspfilter_config *config, void *userdata)
{
float drytime, wettime, damping, roomwidth, roomsize;
struct reverb_data *rev = (struct reverb_data*)
calloc(1, sizeof(*rev));
if (!rev)
return NULL;
config->get_float(userdata, "drytime", &drytime, 0.43f);
config->get_float(userdata, "wettime", &wettime, 0.4f);
config->get_float(userdata, "damping", &damping, 0.8f);
config->get_float(userdata, "roomwidth", &roomwidth, 0.56f);
config->get_float(userdata, "roomsize", &roomsize, 0.56f);
revmodel_init(&rev->left,info->input_rate, false);
revmodel_init(&rev->right,info->input_rate, true);
revmodel_setdamp(&rev->left, damping);
revmodel_setdry(&rev->left, drytime);
revmodel_setwet(&rev->left, wettime);
revmodel_setwidth(&rev->left, roomwidth);
revmodel_setroomsize(&rev->left, roomsize);
revmodel_setdamp(&rev->right, damping);
revmodel_setdry(&rev->right, drytime);
revmodel_setwet(&rev->right, wettime);
revmodel_setwidth(&rev->right, roomwidth);
revmodel_setroomsize(&rev->right, roomsize);
return rev;
}
static const struct dspfilter_implementation reverb_plug = {
reverb_init,
reverb_process,
reverb_free,
DSPFILTER_API_VERSION,
"Reverb",
"reverb",
};
#ifdef HAVE_FILTERS_BUILTIN
#define dspfilter_get_implementation reverb_dspfilter_get_implementation
#endif
const struct dspfilter_implementation *dspfilter_get_implementation(dspfilter_simd_mask_t mask)
{
return &reverb_plug;
}
#undef dspfilter_get_implementation