| 1 | /* |
| 2 | * Copyright (c) 2011 Michael Niedermayer |
| 3 | * |
| 4 | * This file is part of FFmpeg. |
| 5 | * |
| 6 | * FFmpeg is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * FFmpeg is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with FFmpeg; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | * |
| 20 | * The vsrc_color filter from Stefano Sabatini was used as template to create |
| 21 | * this |
| 22 | */ |
| 23 | |
| 24 | /** |
| 25 | * @file |
| 26 | * Mandelbrot fraktal renderer |
| 27 | */ |
| 28 | |
| 29 | #include "avfilter.h" |
| 30 | #include "formats.h" |
| 31 | #include "video.h" |
| 32 | #include "internal.h" |
| 33 | #include "libavutil/imgutils.h" |
| 34 | #include "libavutil/opt.h" |
| 35 | #include "libavutil/parseutils.h" |
| 36 | #include <float.h> |
| 37 | #include <math.h> |
| 38 | |
| 39 | #define SQR(a) ((a)*(a)) |
| 40 | |
| 41 | enum Outer{ |
| 42 | ITERATION_COUNT, |
| 43 | NORMALIZED_ITERATION_COUNT, |
| 44 | WHITE, |
| 45 | OUTZ, |
| 46 | }; |
| 47 | |
| 48 | enum Inner{ |
| 49 | BLACK, |
| 50 | PERIOD, |
| 51 | CONVTIME, |
| 52 | MINCOL, |
| 53 | }; |
| 54 | |
| 55 | typedef struct Point { |
| 56 | double p[2]; |
| 57 | uint32_t val; |
| 58 | } Point; |
| 59 | |
| 60 | typedef struct { |
| 61 | const AVClass *class; |
| 62 | int w, h; |
| 63 | AVRational frame_rate; |
| 64 | uint64_t pts; |
| 65 | int maxiter; |
| 66 | double start_x; |
| 67 | double start_y; |
| 68 | double start_scale; |
| 69 | double end_scale; |
| 70 | double end_pts; |
| 71 | double bailout; |
| 72 | enum Outer outer; |
| 73 | enum Inner inner; |
| 74 | int cache_allocated; |
| 75 | int cache_used; |
| 76 | Point *point_cache; |
| 77 | Point *next_cache; |
| 78 | double (*zyklus)[2]; |
| 79 | uint32_t dither; |
| 80 | |
| 81 | double morphxf; |
| 82 | double morphyf; |
| 83 | double morphamp; |
| 84 | } MBContext; |
| 85 | |
| 86 | #define OFFSET(x) offsetof(MBContext, x) |
| 87 | #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM |
| 88 | |
| 89 | static const AVOption mandelbrot_options[] = { |
| 90 | {"size", "set frame size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str="640x480"}, CHAR_MIN, CHAR_MAX, FLAGS }, |
| 91 | {"s", "set frame size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str="640x480"}, CHAR_MIN, CHAR_MAX, FLAGS }, |
| 92 | {"rate", "set frame rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, CHAR_MIN, CHAR_MAX, FLAGS }, |
| 93 | {"r", "set frame rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, CHAR_MIN, CHAR_MAX, FLAGS }, |
| 94 | {"maxiter", "set max iterations number", OFFSET(maxiter), AV_OPT_TYPE_INT, {.i64=7189}, 1, INT_MAX, FLAGS }, |
| 95 | {"start_x", "set the initial x position", OFFSET(start_x), AV_OPT_TYPE_DOUBLE, {.dbl=-0.743643887037158704752191506114774}, -100, 100, FLAGS }, |
| 96 | {"start_y", "set the initial y position", OFFSET(start_y), AV_OPT_TYPE_DOUBLE, {.dbl=-0.131825904205311970493132056385139}, -100, 100, FLAGS }, |
| 97 | {"start_scale", "set the initial scale value", OFFSET(start_scale), AV_OPT_TYPE_DOUBLE, {.dbl=3.0}, 0, FLT_MAX, FLAGS }, |
| 98 | {"end_scale", "set the terminal scale value", OFFSET(end_scale), AV_OPT_TYPE_DOUBLE, {.dbl=0.3}, 0, FLT_MAX, FLAGS }, |
| 99 | {"end_pts", "set the terminal pts value", OFFSET(end_pts), AV_OPT_TYPE_DOUBLE, {.dbl=400}, 0, INT64_MAX, FLAGS }, |
| 100 | {"bailout", "set the bailout value", OFFSET(bailout), AV_OPT_TYPE_DOUBLE, {.dbl=10}, 0, FLT_MAX, FLAGS }, |
| 101 | {"morphxf", "set morph x frequency", OFFSET(morphxf), AV_OPT_TYPE_DOUBLE, {.dbl=0.01}, -FLT_MAX, FLT_MAX, FLAGS }, |
| 102 | {"morphyf", "set morph y frequency", OFFSET(morphyf), AV_OPT_TYPE_DOUBLE, {.dbl=0.0123}, -FLT_MAX, FLT_MAX, FLAGS }, |
| 103 | {"morphamp", "set morph amplitude", OFFSET(morphamp), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -FLT_MAX, FLT_MAX, FLAGS }, |
| 104 | |
| 105 | {"outer", "set outer coloring mode", OFFSET(outer), AV_OPT_TYPE_INT, {.i64=NORMALIZED_ITERATION_COUNT}, 0, INT_MAX, FLAGS, "outer" }, |
| 106 | {"iteration_count", "set iteration count mode", 0, AV_OPT_TYPE_CONST, {.i64=ITERATION_COUNT}, INT_MIN, INT_MAX, FLAGS, "outer" }, |
| 107 | {"normalized_iteration_count", "set normalized iteration count mode", 0, AV_OPT_TYPE_CONST, {.i64=NORMALIZED_ITERATION_COUNT}, INT_MIN, INT_MAX, FLAGS, "outer" }, |
| 108 | {"white", "set white mode", 0, AV_OPT_TYPE_CONST, {.i64=WHITE}, INT_MIN, INT_MAX, FLAGS, "outer" }, |
| 109 | {"outz", "set outz mode", 0, AV_OPT_TYPE_CONST, {.i64=OUTZ}, INT_MIN, INT_MAX, FLAGS, "outer" }, |
| 110 | |
| 111 | {"inner", "set inner coloring mode", OFFSET(inner), AV_OPT_TYPE_INT, {.i64=MINCOL}, 0, INT_MAX, FLAGS, "inner" }, |
| 112 | {"black", "set black mode", 0, AV_OPT_TYPE_CONST, {.i64=BLACK}, INT_MIN, INT_MAX, FLAGS, "inner"}, |
| 113 | {"period", "set period mode", 0, AV_OPT_TYPE_CONST, {.i64=PERIOD}, INT_MIN, INT_MAX, FLAGS, "inner"}, |
| 114 | {"convergence", "show time until convergence", 0, AV_OPT_TYPE_CONST, {.i64=CONVTIME}, INT_MIN, INT_MAX, FLAGS, "inner"}, |
| 115 | {"mincol", "color based on point closest to the origin of the iterations", 0, AV_OPT_TYPE_CONST, {.i64=MINCOL}, INT_MIN, INT_MAX, FLAGS, "inner"}, |
| 116 | |
| 117 | {NULL}, |
| 118 | }; |
| 119 | |
| 120 | AVFILTER_DEFINE_CLASS(mandelbrot); |
| 121 | |
| 122 | static av_cold int init(AVFilterContext *ctx) |
| 123 | { |
| 124 | MBContext *mb = ctx->priv; |
| 125 | |
| 126 | mb->bailout *= mb->bailout; |
| 127 | |
| 128 | mb->start_scale /=mb->h; |
| 129 | mb->end_scale /=mb->h; |
| 130 | |
| 131 | mb->cache_allocated = mb->w * mb->h * 3; |
| 132 | mb->cache_used = 0; |
| 133 | mb->point_cache= av_malloc_array(mb->cache_allocated, sizeof(*mb->point_cache)); |
| 134 | mb-> next_cache= av_malloc_array(mb->cache_allocated, sizeof(*mb-> next_cache)); |
| 135 | mb-> zyklus = av_malloc_array(mb->maxiter + 16, sizeof(*mb->zyklus)); |
| 136 | |
| 137 | return 0; |
| 138 | } |
| 139 | |
| 140 | static av_cold void uninit(AVFilterContext *ctx) |
| 141 | { |
| 142 | MBContext *mb = ctx->priv; |
| 143 | |
| 144 | av_freep(&mb->point_cache); |
| 145 | av_freep(&mb-> next_cache); |
| 146 | av_freep(&mb->zyklus); |
| 147 | } |
| 148 | |
| 149 | static int query_formats(AVFilterContext *ctx) |
| 150 | { |
| 151 | static const enum AVPixelFormat pix_fmts[] = { |
| 152 | AV_PIX_FMT_BGR32, |
| 153 | AV_PIX_FMT_NONE |
| 154 | }; |
| 155 | |
| 156 | ff_set_common_formats(ctx, ff_make_format_list(pix_fmts)); |
| 157 | return 0; |
| 158 | } |
| 159 | |
| 160 | static int config_props(AVFilterLink *inlink) |
| 161 | { |
| 162 | AVFilterContext *ctx = inlink->src; |
| 163 | MBContext *mb = ctx->priv; |
| 164 | |
| 165 | if (av_image_check_size(mb->w, mb->h, 0, ctx) < 0) |
| 166 | return AVERROR(EINVAL); |
| 167 | |
| 168 | inlink->w = mb->w; |
| 169 | inlink->h = mb->h; |
| 170 | inlink->time_base = av_inv_q(mb->frame_rate); |
| 171 | |
| 172 | return 0; |
| 173 | } |
| 174 | |
| 175 | static void fill_from_cache(AVFilterContext *ctx, uint32_t *color, int *in_cidx, int *out_cidx, double py, double scale){ |
| 176 | MBContext *mb = ctx->priv; |
| 177 | if(mb->morphamp) |
| 178 | return; |
| 179 | for(; *in_cidx < mb->cache_used; (*in_cidx)++){ |
| 180 | Point *p= &mb->point_cache[*in_cidx]; |
| 181 | int x; |
| 182 | if(p->p[1] > py) |
| 183 | break; |
| 184 | x= round((p->p[0] - mb->start_x) / scale + mb->w/2); |
| 185 | if(x<0 || x >= mb->w) |
| 186 | continue; |
| 187 | if(color) color[x] = p->val; |
| 188 | if(out_cidx && *out_cidx < mb->cache_allocated) |
| 189 | mb->next_cache[(*out_cidx)++]= *p; |
| 190 | } |
| 191 | } |
| 192 | |
| 193 | static int interpol(MBContext *mb, uint32_t *color, int x, int y, int linesize) |
| 194 | { |
| 195 | uint32_t a,b,c,d, i; |
| 196 | uint32_t ipol=0xFF000000; |
| 197 | int dist; |
| 198 | |
| 199 | if(!x || !y || x+1==mb->w || y+1==mb->h) |
| 200 | return 0; |
| 201 | |
| 202 | dist= FFMAX(FFABS(x-(mb->w>>1))*mb->h, FFABS(y-(mb->h>>1))*mb->w); |
| 203 | |
| 204 | if(dist<(mb->w*mb->h>>3)) |
| 205 | return 0; |
| 206 | |
| 207 | a=color[(x+1) + (y+0)*linesize]; |
| 208 | b=color[(x-1) + (y+1)*linesize]; |
| 209 | c=color[(x+0) + (y+1)*linesize]; |
| 210 | d=color[(x+1) + (y+1)*linesize]; |
| 211 | |
| 212 | if(a&&c){ |
| 213 | b= color[(x-1) + (y+0)*linesize]; |
| 214 | d= color[(x+0) + (y-1)*linesize]; |
| 215 | }else if(b&&d){ |
| 216 | a= color[(x+1) + (y-1)*linesize]; |
| 217 | c= color[(x-1) + (y-1)*linesize]; |
| 218 | }else if(c){ |
| 219 | d= color[(x+0) + (y-1)*linesize]; |
| 220 | a= color[(x-1) + (y+0)*linesize]; |
| 221 | b= color[(x+1) + (y-1)*linesize]; |
| 222 | }else if(d){ |
| 223 | c= color[(x-1) + (y-1)*linesize]; |
| 224 | a= color[(x-1) + (y+0)*linesize]; |
| 225 | b= color[(x+1) + (y-1)*linesize]; |
| 226 | }else |
| 227 | return 0; |
| 228 | |
| 229 | for(i=0; i<3; i++){ |
| 230 | int s= 8*i; |
| 231 | uint8_t ac= a>>s; |
| 232 | uint8_t bc= b>>s; |
| 233 | uint8_t cc= c>>s; |
| 234 | uint8_t dc= d>>s; |
| 235 | int ipolab= (ac + bc); |
| 236 | int ipolcd= (cc + dc); |
| 237 | if(FFABS(ipolab - ipolcd) > 5) |
| 238 | return 0; |
| 239 | if(FFABS(ac-bc)+FFABS(cc-dc) > 20) |
| 240 | return 0; |
| 241 | ipol |= ((ipolab + ipolcd + 2)/4)<<s; |
| 242 | } |
| 243 | color[x + y*linesize]= ipol; |
| 244 | return 1; |
| 245 | } |
| 246 | |
| 247 | static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize, int64_t pts) |
| 248 | { |
| 249 | MBContext *mb = ctx->priv; |
| 250 | int x,y,i, in_cidx=0, next_cidx=0, tmp_cidx; |
| 251 | double scale= mb->start_scale*pow(mb->end_scale/mb->start_scale, pts/mb->end_pts); |
| 252 | int use_zyklus=0; |
| 253 | fill_from_cache(ctx, NULL, &in_cidx, NULL, mb->start_y+scale*(-mb->h/2-0.5), scale); |
| 254 | tmp_cidx= in_cidx; |
| 255 | memset(color, 0, sizeof(*color)*mb->w); |
| 256 | for(y=0; y<mb->h; y++){ |
| 257 | int y1= y+1; |
| 258 | const double ci=mb->start_y+scale*(y-mb->h/2); |
| 259 | fill_from_cache(ctx, NULL, &in_cidx, &next_cidx, ci, scale); |
| 260 | if(y1<mb->h){ |
| 261 | memset(color+linesize*y1, 0, sizeof(*color)*mb->w); |
| 262 | fill_from_cache(ctx, color+linesize*y1, &tmp_cidx, NULL, ci + 3*scale/2, scale); |
| 263 | } |
| 264 | |
| 265 | for(x=0; x<mb->w; x++){ |
| 266 | float av_uninit(epsilon); |
| 267 | const double cr=mb->start_x+scale*(x-mb->w/2); |
| 268 | double zr=cr; |
| 269 | double zi=ci; |
| 270 | uint32_t c=0; |
| 271 | double dv= mb->dither / (double)(1LL<<32); |
| 272 | mb->dither= mb->dither*1664525+1013904223; |
| 273 | |
| 274 | if(color[x + y*linesize] & 0xFF000000) |
| 275 | continue; |
| 276 | if(!mb->morphamp){ |
| 277 | if(interpol(mb, color, x, y, linesize)){ |
| 278 | if(next_cidx < mb->cache_allocated){ |
| 279 | mb->next_cache[next_cidx ].p[0]= cr; |
| 280 | mb->next_cache[next_cidx ].p[1]= ci; |
| 281 | mb->next_cache[next_cidx++].val = color[x + y*linesize]; |
| 282 | } |
| 283 | continue; |
| 284 | } |
| 285 | }else{ |
| 286 | zr += cos(pts * mb->morphxf) * mb->morphamp; |
| 287 | zi += sin(pts * mb->morphyf) * mb->morphamp; |
| 288 | } |
| 289 | |
| 290 | use_zyklus= (x==0 || mb->inner!=BLACK ||color[x-1 + y*linesize] == 0xFF000000); |
| 291 | if(use_zyklus) |
| 292 | epsilon= scale*1*sqrt(SQR(x-mb->w/2) + SQR(y-mb->h/2))/mb->w; |
| 293 | |
| 294 | #define Z_Z2_C(outr,outi,inr,ini)\ |
| 295 | outr= inr*inr - ini*ini + cr;\ |
| 296 | outi= 2*inr*ini + ci; |
| 297 | |
| 298 | #define Z_Z2_C_ZYKLUS(outr,outi,inr,ini, Z)\ |
| 299 | Z_Z2_C(outr,outi,inr,ini)\ |
| 300 | if(use_zyklus){\ |
| 301 | if(Z && fabs(mb->zyklus[i>>1][0]-outr)+fabs(mb->zyklus[i>>1][1]-outi) <= epsilon)\ |
| 302 | break;\ |
| 303 | }\ |
| 304 | mb->zyklus[i][0]= outr;\ |
| 305 | mb->zyklus[i][1]= outi;\ |
| 306 | |
| 307 | |
| 308 | |
| 309 | for(i=0; i<mb->maxiter-8; i++){ |
| 310 | double t; |
| 311 | Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0) |
| 312 | i++; |
| 313 | Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1) |
| 314 | i++; |
| 315 | Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0) |
| 316 | i++; |
| 317 | Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1) |
| 318 | i++; |
| 319 | Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0) |
| 320 | i++; |
| 321 | Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1) |
| 322 | i++; |
| 323 | Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0) |
| 324 | i++; |
| 325 | Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1) |
| 326 | if(zr*zr + zi*zi > mb->bailout){ |
| 327 | i-= FFMIN(7, i); |
| 328 | for(; i<mb->maxiter; i++){ |
| 329 | zr= mb->zyklus[i][0]; |
| 330 | zi= mb->zyklus[i][1]; |
| 331 | if(zr*zr + zi*zi > mb->bailout){ |
| 332 | switch(mb->outer){ |
| 333 | case ITERATION_COUNT: |
| 334 | zr = i; |
| 335 | c = lrintf((sin(zr)+1)*127) + lrintf((sin(zr/1.234)+1)*127)*256*256 + lrintf((sin(zr/100)+1)*127)*256; |
| 336 | break; |
| 337 | case NORMALIZED_ITERATION_COUNT: |
| 338 | zr = i + log2(log(mb->bailout) / log(zr*zr + zi*zi)); |
| 339 | c = lrintf((sin(zr)+1)*127) + lrintf((sin(zr/1.234)+1)*127)*256*256 + lrintf((sin(zr/100)+1)*127)*256; |
| 340 | break; |
| 341 | case WHITE: |
| 342 | c = 0xFFFFFF; |
| 343 | break; |
| 344 | case OUTZ: |
| 345 | zr /= mb->bailout; |
| 346 | zi /= mb->bailout; |
| 347 | c = (((int)(zr*128+128))&0xFF)*256 + (((int)(zi*128+128))&0xFF); |
| 348 | } |
| 349 | break; |
| 350 | } |
| 351 | } |
| 352 | break; |
| 353 | } |
| 354 | } |
| 355 | if(!c){ |
| 356 | if(mb->inner==PERIOD){ |
| 357 | int j; |
| 358 | for(j=i-1; j; j--) |
| 359 | if(SQR(mb->zyklus[j][0]-zr) + SQR(mb->zyklus[j][1]-zi) < epsilon*epsilon*10) |
| 360 | break; |
| 361 | if(j){ |
| 362 | c= i-j; |
| 363 | c= ((c<<5)&0xE0) + ((c<<10)&0xE000) + ((c<<15)&0xE00000); |
| 364 | } |
| 365 | }else if(mb->inner==CONVTIME){ |
| 366 | c= floor(i*255.0/mb->maxiter+dv)*0x010101; |
| 367 | } else if(mb->inner==MINCOL){ |
| 368 | int j; |
| 369 | double closest=9999; |
| 370 | int closest_index=0; |
| 371 | for(j=i-1; j>=0; j--) |
| 372 | if(SQR(mb->zyklus[j][0]) + SQR(mb->zyklus[j][1]) < closest){ |
| 373 | closest= SQR(mb->zyklus[j][0]) + SQR(mb->zyklus[j][1]); |
| 374 | closest_index= j; |
| 375 | } |
| 376 | closest = sqrt(closest); |
| 377 | c= lrintf((mb->zyklus[closest_index][0]/closest+1)*127+dv) + lrintf((mb->zyklus[closest_index][1]/closest+1)*127+dv)*256; |
| 378 | } |
| 379 | } |
| 380 | c |= 0xFF000000; |
| 381 | color[x + y*linesize]= c; |
| 382 | if(next_cidx < mb->cache_allocated){ |
| 383 | mb->next_cache[next_cidx ].p[0]= cr; |
| 384 | mb->next_cache[next_cidx ].p[1]= ci; |
| 385 | mb->next_cache[next_cidx++].val = c; |
| 386 | } |
| 387 | } |
| 388 | fill_from_cache(ctx, NULL, &in_cidx, &next_cidx, ci + scale/2, scale); |
| 389 | } |
| 390 | FFSWAP(void*, mb->next_cache, mb->point_cache); |
| 391 | mb->cache_used = next_cidx; |
| 392 | if(mb->cache_used == mb->cache_allocated) |
| 393 | av_log(ctx, AV_LOG_INFO, "Mandelbrot cache is too small!\n"); |
| 394 | } |
| 395 | |
| 396 | static int request_frame(AVFilterLink *link) |
| 397 | { |
| 398 | MBContext *mb = link->src->priv; |
| 399 | AVFrame *picref = ff_get_video_buffer(link, mb->w, mb->h); |
| 400 | if (!picref) |
| 401 | return AVERROR(ENOMEM); |
| 402 | |
| 403 | picref->sample_aspect_ratio = (AVRational) {1, 1}; |
| 404 | picref->pts = mb->pts++; |
| 405 | |
| 406 | draw_mandelbrot(link->src, (uint32_t*)picref->data[0], picref->linesize[0]/4, picref->pts); |
| 407 | return ff_filter_frame(link, picref); |
| 408 | } |
| 409 | |
| 410 | static const AVFilterPad mandelbrot_outputs[] = { |
| 411 | { |
| 412 | .name = "default", |
| 413 | .type = AVMEDIA_TYPE_VIDEO, |
| 414 | .request_frame = request_frame, |
| 415 | .config_props = config_props, |
| 416 | }, |
| 417 | { NULL } |
| 418 | }; |
| 419 | |
| 420 | AVFilter ff_vsrc_mandelbrot = { |
| 421 | .name = "mandelbrot", |
| 422 | .description = NULL_IF_CONFIG_SMALL("Render a Mandelbrot fractal."), |
| 423 | .priv_size = sizeof(MBContext), |
| 424 | .priv_class = &mandelbrot_class, |
| 425 | .init = init, |
| 426 | .uninit = uninit, |
| 427 | .query_formats = query_formats, |
| 428 | .inputs = NULL, |
| 429 | .outputs = mandelbrot_outputs, |
| 430 | }; |