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livetrax/libs/plugins/a-reverb.lv2/a-reverb.c

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/* a-reverb -- based on b_reverb (setBfree) and FreeVerb
*
* Copyright (C) 2003-2004 Fredrik Kilander <fk@dsv.su.se>
* Copyright (C) 2008-2016 Robin Gareus <robin@gareus.org>
* Copyright (C) 2012 Will Panther <pantherb@setbfree.org>
* Copyright (C) 2016 Damien Zammit <damien@zamaudio.com>
*
* 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 2, 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/>.
*/
#ifndef _GNU_SOURCE
#define _GNU_SOURCE // needed for M_PI
#endif
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <math.h>
#include <string.h>
#define RV_NZ 7
#define DENORMAL_PROTECT (1e-14)
#ifdef COMPILER_MSVC
#include <float.h>
#define isfinite_local(val) (bool)_finite((double)val)
#else
#define isfinite_local isfinite
#endif
typedef struct {
float* delays[2][RV_NZ]; /**< delay line buffer */
size_t size[2][RV_NZ];
float* idx0[2][RV_NZ]; /**< Reset pointer ref delays[]*/
float* idxp[2][RV_NZ]; /**< Index pointer ref delays[]*/
float* endp[2][RV_NZ]; /**< End pointer ref delays[]*/
float gain[RV_NZ]; /**< feedback gains */
float yy1_0; /**< Previous output sample */
float y_1_0; /**< Feedback sample */
float yy1_1; /**< Previous output sample */
float y_1_1; /**< Feedback sample */
int end[2][RV_NZ];
float inputGain; /**< Input gain value */
float fbk; /**< Feedback gain */
float wet; /**< Output dry gain */
float dry; /**< Output wet gain */
} b_reverb;
static int
setReverbPointers (b_reverb *r, int i, int c, const double rate)
{
int e = (r->end[c][i] * rate / 25000.0);
e = e | 1;
r->size[c][i] = e + 2;
r->delays[c][i] = (float*)realloc ((void*)r->delays[c][i], r->size[c][i] * sizeof (float));
if (!r->delays[c][i]) {
return -1;
} else {
memset (r->delays[c][i], 0 , r->size[c][i] * sizeof (float));
}
r->endp[c][i] = r->delays[c][i] + e + 1;
r->idx0[c][i] = r->idxp[c][i] = &(r->delays[c][i][0]);
return 0;
}
static int
initReverb (b_reverb *r, const double rate)
{
int err = 0;
int stereowidth = 7;
r->inputGain = powf (10.0, .05 * -20.0); // -20dB
r->fbk = -0.015; /* Feedback gain */
r->wet = 0.3;
r->dry = 0.7;
/* feedback combfilter */
r->gain[0] = 0.773;
r->gain[1] = 0.802;
r->gain[2] = 0.753;
r->gain[3] = 0.733;
/* all-pass filter */
r->gain[4] = sqrtf (0.5);
r->gain[5] = sqrtf (0.5);
r->gain[6] = sqrtf (0.5);
/* delay lines left */
r->end[0][0] = 1687;
r->end[0][1] = 1601;
r->end[0][2] = 2053;
r->end[0][3] = 2251;
/* all pass filters left */
r->end[0][4] = 347;
r->end[0][5] = 113;
r->end[0][6] = 37;
/* delay lines right */
r->end[1][0] = 1687 + stereowidth;
r->end[1][1] = 1601 + stereowidth;
r->end[1][2] = 2053 + stereowidth;
r->end[1][3] = 2251 + stereowidth;
/* all pass filters right */
r->end[1][4] = 347 + stereowidth;
r->end[1][5] = 113 + stereowidth;
r->end[1][6] = 37 + stereowidth;
for (int i = 0; i < RV_NZ; ++i) {
r->delays[0][i] = NULL;
r->delays[1][i] = NULL;
}
r->yy1_0 = 0.0;
r->y_1_0 = 0.0;
r->yy1_1 = 0.0;
r->y_1_1 = 0.0;
for (int i = 0; i < RV_NZ; ++i) {
err |= setReverbPointers (r, i, 0, rate);
err |= setReverbPointers (r, i, 1, rate);
}
return err;
}
static void
reverb (b_reverb* r,
const float* inbuf0,
const float* inbuf1,
float* outbuf0,
float* outbuf1,
size_t n_samples)
{
float** const idxp0 = r->idxp[0];
float** const idxp1 = r->idxp[1];
float* const* const endp0 = r->endp[0];
float* const* const endp1 = r->endp[1];
float* const* const idx00 = r->idx0[0];
float* const* const idx01 = r->idx0[1];
const float* const gain = r->gain;
const float inputGain = r->inputGain;
const float fbk = r->fbk;
const float wet = r->wet;
const float dry = r->dry;
const float* xp0 = inbuf0;
const float* xp1 = inbuf1;
float* yp0 = outbuf0;
float* yp1 = outbuf1;
float y_1_0 = r->y_1_0;
float yy1_0 = r->yy1_0;
float y_1_1 = r->y_1_1;
float yy1_1 = r->yy1_1;
for (size_t i = 0; i < n_samples; ++i) {
int j;
float y;
float xo0 = *xp0++;
float xo1 = *xp1++;
if (!isfinite_local(xo0) || fabsf (xo0) > 10.f) { xo0 = 0; }
if (!isfinite_local(xo1) || fabsf (xo1) > 10.f) { xo1 = 0; }
xo0 += DENORMAL_PROTECT;
xo1 += DENORMAL_PROTECT;
const float x0 = y_1_0 + (inputGain * xo0);
const float x1 = y_1_1 + (inputGain * xo1);
float xa = 0.0;
float xb = 0.0;
/* First we do four feedback comb filters (ie parallel delay lines,
* each with a single tap at the end that feeds back at the start) */
for (j = 0; j < 4; ++j) {
y = *idxp0[j];
*idxp0[j] = x0 + (gain[j] * y);
if (endp0[j] <= ++(idxp0[j])) {
idxp0[j] = idx00[j];
}
xa += y;
}
for (; j < 7; ++j) {
y = *idxp0[j];
*idxp0[j] = gain[j] * (xa + y);
if (endp0[j] <= ++(idxp0[j])) {
idxp0[j] = idx00[j];
}
xa = y - xa;
}
y = 0.5f * (xa + yy1_0);
yy1_0 = y;
y_1_0 = fbk * xa;
*yp0++ = ((wet * y) + (dry * xo0));
for (j = 0; j < 4; ++j) {
y = *idxp1[j];
*idxp1[j] = x1 + (gain[j] * y);
if (endp1[j] <= ++(idxp1[j])) {
idxp1[j] = idx01[j];
}
xb += y;
}
for (; j < 7; ++j) {
y = *idxp1[j];
*idxp1[j] = gain[j] * (xb + y);
if (endp1[j] <= ++(idxp1[j])) {
idxp1[j] = idx01[j];
}
xb = y - xb;
}
y = 0.5f * (xb + yy1_1);
yy1_1 = y;
y_1_1 = fbk * xb;
*yp1++ = ((wet * y) + (dry * xo1));
}
if (!isfinite_local(y_1_0)) { y_1_0 = 0; }
if (!isfinite_local(yy1_1)) { yy1_0 = 0; }
if (!isfinite_local(y_1_1)) { y_1_1 = 0; }
if (!isfinite_local(yy1_1)) { yy1_1 = 0; }
r->y_1_0 = y_1_0 + DENORMAL_PROTECT;
r->yy1_0 = yy1_0 + DENORMAL_PROTECT;
r->y_1_1 = y_1_1 + DENORMAL_PROTECT;
r->yy1_1 = yy1_1 + DENORMAL_PROTECT;
}
/******************************************************************************
* LV2 wrapper
*/
#include "lv2/lv2plug.in/ns/lv2core/lv2.h"
typedef enum {
AR_INPUT0 = 0,
AR_INPUT1 = 1,
AR_OUTPUT0 = 2,
AR_OUTPUT1 = 3,
AR_MIX = 4,
AR_ROOMSZ = 5,
AR_ENABLE = 6,
} PortIndex;
typedef struct {
float* input0;
float* input1;
float* output0;
float* output1;
float* mix;
float* roomsz;
float* enable;
float v_mix;
float v_roomsz;
float srate;
float tau;
b_reverb r;
} AReverb;
static LV2_Handle
instantiate (const LV2_Descriptor* descriptor,
double rate,
const char* bundle_path,
const LV2_Feature* const* features)
{
AReverb* self = (AReverb*)calloc (1, sizeof (AReverb));
if (!self) {
return NULL;
}
if (initReverb (&self->r, rate)) {
return NULL;
}
// these are set in initReverb()
self->v_roomsz = 0.75;
self->v_mix = 0.1;
self->srate = rate;
self->tau = 1.f - expf (-2.f * M_PI * 64.f * 15.f / self->srate); // 15Hz, 64fpp
return (LV2_Handle)self;
}
static void
connect_port (LV2_Handle instance,
uint32_t port,
void* data)
{
AReverb* self = (AReverb*)instance;
switch ((PortIndex)port) {
case AR_INPUT0:
self->input0 = (float*)data;
break;
case AR_INPUT1:
self->input1 = (float*)data;
break;
case AR_OUTPUT0:
self->output0 = (float*)data;
break;
case AR_OUTPUT1:
self->output1 = (float*)data;
break;
case AR_MIX:
self->mix = (float*)data;
break;
case AR_ROOMSZ:
self->roomsz = (float*)data;
break;
case AR_ENABLE:
self->enable = (float*)data;
break;
}
}
static void
activate (LV2_Handle instance)
{
AReverb* self = (AReverb*)instance;
self->r.y_1_0 = 0;
self->r.yy1_0 = 0;
self->r.y_1_1 = 0;
self->r.yy1_1 = 0;
for (int i = 0; i < RV_NZ; ++i) {
for (int c = 0; c < 2; ++c) {
memset (self->r.delays[c][i], 0, self->r.size[c][i] * sizeof (float));
}
}
}
static void
deactivate (LV2_Handle instance)
{
activate(instance);
}
static void
run (LV2_Handle instance, uint32_t n_samples)
{
AReverb* self = (AReverb*)instance;
const float* const input0 = self->input0;
const float* const input1 = self->input1;
float* const output0 = self->output0;
float* const output1 = self->output1;
const float tau = self->tau;
const float mix = *self->enable <= 0 ? 0 : *self->mix;
uint32_t remain = n_samples;
uint32_t offset = 0;
uint32_t iterpolate = 0;
if (fabsf (mix - self->v_mix) < .01) { // 40dB
if (self->v_mix != mix && *self->enable <= 0) {
// entering bypass, reset reverb
activate (self);
}
self->v_mix = mix;
self->r.wet = self->v_mix;
self->r.dry = 1.0 - self->v_mix;
} else {
iterpolate |= 1;
}
if (fabsf (*self->roomsz - self->v_roomsz) < .01) {
self->v_roomsz = *self->roomsz;
} else {
iterpolate |= 2;
}
while (remain > 0) {
uint32_t p_samples = remain;
if (iterpolate && p_samples > 64) {
p_samples = 64;
}
if (iterpolate & 1) {
self->v_mix += tau * (mix - self->v_mix);
self->r.wet = self->v_mix;
self->r.dry = 1.0 - self->v_mix;
}
if (iterpolate & 2) {
self->v_roomsz += tau * ( *self->roomsz - self->v_roomsz);
self->r.gain[0] = 0.773 * self->v_roomsz;
self->r.gain[1] = 0.802 * self->v_roomsz;
self->r.gain[2] = 0.753 * self->v_roomsz;
self->r.gain[3] = 0.733 * self->v_roomsz;
}
reverb (&self->r,
&input0[offset], &input1[offset],
&output0[offset], &output1[offset],
p_samples);
offset += p_samples;
remain -= p_samples;
}
}
static void
cleanup (LV2_Handle instance)
{
AReverb* self = (AReverb*)instance;
for (int i = 0; i < RV_NZ; ++i) {
free (self->r.delays[0][i]);
free (self->r.delays[1][i]);
}
free (instance);
}
static const void*
extension_data (const char* uri)
{
return NULL;
}
static const LV2_Descriptor descriptor = {
"urn:ardour:a-reverb",
instantiate,
connect_port,
activate,
run,
deactivate,
cleanup,
extension_data
};
LV2_SYMBOL_EXPORT
const LV2_Descriptor*
lv2_descriptor (uint32_t index)
{
switch (index) {
case 0:
return &descriptor;
default:
return NULL;
}
}
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