libs/plugins/a-comp.lv2/a-comp.c

   1 /* a-comp
   2  * Copyright (C) 2016 Damien Zammit <damien@zamaudio.com>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <math.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <stdbool.h>
  19
  20 #ifdef LV2_EXTENDED
  21 #include <cairo/cairo.h>
  22 #include "ardour/lv2_extensions.h"
  23 #endif
  24
  25 #include "lv2/lv2plug.in/ns/lv2core/lv2.h"
  26
  27 #define ACOMP_URI "urn:ardour:a-comp"
  28
  29 typedef enum {
  30         ACOMP_INPUT0 = 0,
  31         ACOMP_INPUT1,
  32         ACOMP_OUTPUT,
  33
  34         ACOMP_ATTACK,
  35         ACOMP_RELEASE,
  36         ACOMP_KNEE,
  37         ACOMP_RATIO,
  38         ACOMP_THRESHOLD,
  39         ACOMP_MAKEUP,
  40
  41         ACOMP_GAINR,
  42         ACOMP_OUTLEVEL,
  43         ACOMP_SIDECHAIN,
  44 } PortIndex;
  45
  46
  47 typedef struct {
  48         float* input0;
  49         float* input1;
  50         float* output;
  51
  52         float* attack;
  53         float* release;
  54         float* knee;
  55         float* ratio;
  56         float* thresdb;
  57         float* makeup;
  58
  59         float* gainr;
  60         float* outlevel;
  61         float* sidechain;
  62
  63         float srate;
  64         float old_yl;
  65         float old_y1;
  66         float old_yg;
  67
  68 #ifdef LV2_EXTENDED
  69         bool                     need_expose;
  70         LV2_Inline_Display_Image_Surface surf;
  71         cairo_surface_t*         display;
  72         LV2_Inline_Display*      queue_draw;
  73         uint32_t                 w, h;
  74
  75         /* ports pointers are only valid during run so we'll
  76          * have to cache them for the display, besides
  77          * we do want to check for changes
  78          */
  79         float v_knee;
  80         float v_ratio;
  81         float v_thresdb;
  82         float v_lvl;
  83 #endif
  84 } AComp;
  85
  86 static LV2_Handle
  87 instantiate(const LV2_Descriptor* descriptor,
  88             double rate,
  89             const char* bundle_path,
  90             const LV2_Feature* const* features)
  91 {
  92         AComp* acomp = (AComp*)calloc(1, sizeof(AComp));
  93
  94         for (int i=0; features[i]; ++i) {
  95 #ifdef LV2_EXTENDED
  96                 if (!strcmp(features[i]->URI, LV2_INLINEDISPLAY__queue_draw)) {
  97                         acomp->queue_draw = (LV2_Inline_Display*) features[i]->data;
  98                 }
  99 #endif
 100         }
 101
 102         acomp->srate = rate;
 103         acomp->old_yl=acomp->old_y1=acomp->old_yg=0.f;
 104         acomp->need_expose = true;
 105
 106         return (LV2_Handle)acomp;
 107 }
 108
 109 static void
 110 connect_port(LV2_Handle instance,
 111              uint32_t port,
 112              void* data)
 113 {
 114         AComp* acomp = (AComp*)instance;
 115
 116         switch ((PortIndex)port) {
 117         case ACOMP_ATTACK:
 118                 acomp->attack = (float*)data;
 119                 break;
 120         case ACOMP_RELEASE:
 121                 acomp->release = (float*)data;
 122                 break;
 123         case ACOMP_KNEE:
 124                 acomp->knee = (float*)data;
 125                 break;
 126         case ACOMP_RATIO:
 127                 acomp->ratio = (float*)data;
 128                 break;
 129         case ACOMP_THRESHOLD:
 130                 acomp->thresdb = (float*)data;
 131                 break;
 132         case ACOMP_MAKEUP:
 133                 acomp->makeup = (float*)data;
 134                 break;
 135         case ACOMP_GAINR:
 136                 acomp->gainr = (float*)data;
 137                 break;
 138         case ACOMP_OUTLEVEL:
 139                 acomp->outlevel = (float*)data;
 140                 break;
 141         case ACOMP_SIDECHAIN:
 142                 acomp->sidechain = (float*)data;
 143                 break;
 144         case ACOMP_INPUT0:
 145                 acomp->input0 = (float*)data;
 146                 break;
 147         case ACOMP_INPUT1:
 148                 acomp->input1 = (float*)data;
 149                 break;
 150         case ACOMP_OUTPUT:
 151                 acomp->output = (float*)data;
 152                 break;
 153         }
 154 }
 155
 156 // Force already-denormal float value to zero
 157 static inline float
 158 sanitize_denormal(float value) {
 159         if (!isnormal(value)) {
 160                 value = 0.f;
 161         }
 162         return value;
 163 }
 164
 165 static inline float
 166 from_dB(float gdb) {
 167         return (exp(gdb/20.f*log(10.f)));
 168 }
 169
 170 static inline float
 171 to_dB(float g) {
 172         return (20.f*log10(g));
 173 }
 174
 175 static void
 176 activate(LV2_Handle instance)
 177 {
 178         AComp* acomp = (AComp*)instance;
 179
 180         *(acomp->gainr) = 0.0f;
 181         *(acomp->outlevel) = -45.0f;
 182         acomp->old_yl=acomp->old_y1=acomp->old_yg=0.f;
 183 }
 184
 185 static void
 186 run(LV2_Handle instance, uint32_t n_samples)
 187 {
 188         AComp* acomp = (AComp*)instance;
 189
 190         const float* const input0 = acomp->input0;
 191         const float* const input1 = acomp->input1;
 192         float* const output = acomp->output;
 193
 194         float srate = acomp->srate;
 195         float width = (6.f * *(acomp->knee)) + 0.01;
 196         float cdb=0.f;
 197         float attack_coeff = exp(-1000.f/(*(acomp->attack) * srate));
 198         float release_coeff = exp(-1000.f/(*(acomp->release) * srate));
 199
 200         float max = 0.f;
 201         float lgaininp = 0.f;
 202         float Lgain = 1.f;
 203         float Lxg, Lxl, Lyg, Lyl, Ly1;
 204         int usesidechain = (*(acomp->sidechain) < 0.5) ? 0 : 1;
 205         uint32_t i;
 206         float ingain;
 207         float in0;
 208         float in1;
 209         float ratio = *(acomp->ratio);
 210         float thresdb = *(acomp->thresdb);
 211
 212 #ifdef LV2_EXTENDED
 213         if (acomp->v_knee != *acomp->knee) {
 214                 acomp->v_knee = *acomp->knee;
 215                 acomp->need_expose = true;
 216         }
 217
 218         if (acomp->v_ratio != *acomp->ratio) {
 219                 acomp->v_ratio = *acomp->ratio;
 220                 acomp->need_expose = true;
 221         }
 222
 223         if (acomp->v_thresdb != *acomp->thresdb) {
 224                 acomp->v_thresdb = *acomp->thresdb;
 225                 acomp->need_expose = true;
 226         }
 227 #endif
 228
 229         for (i = 0; i < n_samples; i++) {
 230                 in0 = input0[i];
 231                 in1 = input1[i];
 232                 ingain = usesidechain ? in1 : in0;
 233                 Lyg = 0.f;
 234                 Lxg = (ingain==0.f) ? -160.f : to_dB(fabs(ingain));
 235                 Lxg = sanitize_denormal(Lxg);
 236
 237                 Lyg = Lxg + (1.f/ratio-1.f)*(Lxg-thresdb+width/2.f)*(Lxg-thresdb+width/2.f)/(2.f*width);
 238
 239                 if (2.f*(Lxg-thresdb) < -width) {
 240                         Lyg = Lxg;
 241                 } else {
 242                         Lyg = thresdb + (Lxg-thresdb)/ratio;
 243                         Lyg = sanitize_denormal(Lyg);
 244                 }
 245
 246                 Lxl = Lxg - Lyg;
 247
 248                 acomp->old_y1 = sanitize_denormal(acomp->old_y1);
 249                 acomp->old_yl = sanitize_denormal(acomp->old_yl);
 250                 Ly1 = fmaxf(Lxl, release_coeff * acomp->old_y1+(1.f-release_coeff)*Lxl);
 251                 Lyl = attack_coeff * acomp->old_yl+(1.f-attack_coeff)*Ly1;
 252                 Ly1 = sanitize_denormal(Ly1);
 253                 Lyl = sanitize_denormal(Lyl);
 254
 255                 cdb = -Lyl;
 256                 Lgain = from_dB(cdb);
 257
 258                 *(acomp->gainr) = Lyl;
 259
 260                 lgaininp = in0 * Lgain;
 261                 output[i] = lgaininp * from_dB(*(acomp->makeup));
 262
 263                 max = (fabsf(output[i]) > max) ? fabsf(output[i]) : sanitize_denormal(max);
 264
 265                 // TODO re-use local variables on stack
 266                 // store values back to acomp at the end of the inner-loop
 267                 acomp->old_yl = Lyl;
 268                 acomp->old_y1 = Ly1;
 269                 acomp->old_yg = Lyg;
 270         }
 271
 272         *(acomp->outlevel) = (max < 0.0056f) ? -45.f : to_dB(max);
 273
 274 #ifdef LV2_EXTENDED
 275         const float v_lvl = (max < 0.001f) ? -60.f : to_dB(max);
 276         if (fabsf (acomp->v_lvl - v_lvl) >= 1) { // quantize to 1dB difference
 277                 acomp->need_expose = true;
 278                 acomp->v_lvl = v_lvl;
 279         }
 280         if (acomp->need_expose && acomp->queue_draw) {
 281                 acomp->need_expose = false;
 282                 acomp->queue_draw->queue_draw (acomp->queue_draw->handle);
 283         }
 284 #endif
 285 }
 286
 287 static void
 288 deactivate(LV2_Handle instance)
 289 {
 290         activate(instance);
 291 }
 292
 293 static void
 294 cleanup(LV2_Handle instance)
 295 {
 296 #ifdef LV2_EXTENDED
 297         AComp* acomp = (AComp*)instance;
 298         if (acomp->display) {
 299                 cairo_surface_destroy (acomp->display);
 300         }
 301 #endif
 302
 303         free(instance);
 304 }
 305
 306
 307 #ifndef MIN
 308 #define MIN(A,B) ((A) < (B)) ? (A) : (B)
 309 #endif
 310
 311 #ifdef LV2_EXTENDED
 312 static float
 313 comp_curve (AComp* self, float xg) {
 314         const float knee = self->v_knee;
 315         const float ratio = self->v_ratio;
 316         const float thresdb = self->v_thresdb;
 317
 318         const float width = 6.f * knee + 0.01f;
 319         float yg = 0.f;
 320
 321         if (2.f * (xg - thresdb) < -width) {
 322                 yg = xg;
 323         } else if (2.f * fabs (xg - thresdb) <= width) {
 324                 yg = xg + (1.f / ratio - 1.f ) * (xg - thresdb + width / 2.f) * (xg - thresdb + width / 2.f) / (2.f * width);
 325         } else if (2.f * (xg - thresdb) > width) {
 326                 yg = thresdb + (xg - thresdb) / ratio;
 327         }
 328         return yg;
 329 }
 330
 331
 332 static LV2_Inline_Display_Image_Surface *
 333 render_inline (LV2_Handle instance, uint32_t w, uint32_t max_h)
 334 {
 335         AComp* self = (AComp*)instance;
 336         uint32_t h = MIN (w, max_h);
 337
 338         if (!self->display || self->w != w || self->h != h) {
 339                 if (self->display) cairo_surface_destroy(self->display);
 340                 self->display = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, w, h);
 341                 self->w = w;
 342                 self->h = h;
 343         }
 344
 345         cairo_t* cr = cairo_create (self->display);
 346
 347         // clear background
 348         cairo_rectangle (cr, 0, 0, w, h);
 349         cairo_set_source_rgba (cr, .2, .2, .2, 1.0);
 350         cairo_fill (cr);
 351
 352         cairo_set_line_width(cr, 1.0);
 353
 354         // draw grid 10dB steps
 355         const double dash2[] = {1, 3};
 356         cairo_save (cr);
 357         cairo_set_dash(cr, dash2, 2, 2);
 358         cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 0.5);
 359
 360         for (uint32_t d = 1; d < 6; ++d) {
 361                 const float x = -.5 + floorf (w * (d * 10.f / 60.f));
 362                 const float y = -.5 + floorf (h * (d * 10.f / 60.f));
 363
 364                 cairo_move_to (cr, x, 0);
 365                 cairo_line_to (cr, x, h);
 366                 cairo_stroke (cr);
 367
 368                 cairo_move_to (cr, 0, y);
 369                 cairo_line_to (cr, w, y);
 370                 cairo_stroke (cr);
 371         }
 372         cairo_restore (cr);
 373
 374
 375         // draw curve
 376         cairo_set_source_rgba (cr, .8, .8, .8, 1.0);
 377         cairo_move_to (cr, 0, h);
 378
 379         for (uint32_t x = 0; x < w; ++x) {
 380                 // plot -60..0  dB
 381                 const float x_db = 60.f * (-1.f + x / (float)w);
 382                 const float y_db = comp_curve (self, x_db);
 383                 const float y = h * (y_db / -60.f);
 384                 cairo_line_to (cr, x, y);
 385         }
 386         cairo_stroke_preserve (cr);
 387
 388         cairo_line_to (cr, w, h);
 389         cairo_close_path (cr);
 390         cairo_clip (cr);
 391
 392         // draw signal level
 393         // TODO add a gradient pattern above threshold
 394         // maybe cut off at x-position?
 395         const float y = h * (self->v_lvl + 60) / 60.f;
 396         cairo_rectangle (cr, 0, h - y, w, y);
 397         cairo_set_source_rgba (cr, 0.5, 0.5, 0.5, 0.5);
 398         cairo_fill (cr);
 399
 400
 401         // create RGBA surface
 402         cairo_destroy (cr);
 403         cairo_surface_flush (self->display);
 404         self->surf.width = cairo_image_surface_get_width (self->display);
 405         self->surf.height = cairo_image_surface_get_height (self->display);
 406         self->surf.stride = cairo_image_surface_get_stride (self->display);
 407         self->surf.data = cairo_image_surface_get_data  (self->display);
 408
 409         return &self->surf;
 410 }
 411 #endif
 412
 413 static const void*
 414 extension_data(const char* uri)
 415 {
 416         static const LV2_Inline_Display_Interface display  = { render_inline };
 417         if (!strcmp(uri, LV2_INLINEDISPLAY__interface)) {
 418                 return &display;
 419         }
 420         return NULL;
 421 }
 422
 423 static const LV2_Descriptor descriptor = {
 424         ACOMP_URI,
 425         instantiate,
 426         connect_port,
 427         activate,
 428         run,
 429         deactivate,
 430         cleanup,
 431         extension_data
 432 };
 433
 434 LV2_SYMBOL_EXPORT
 435 const LV2_Descriptor*
 436 lv2_descriptor(uint32_t index)
 437 {
 438         switch (index) {
 439         case 0:
 440                 return &descriptor;
 441         default:
 442                 return NULL;
 443         }
 444 }