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 fractal 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 MBContext {
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 int outer;
73 int 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"}, 0, 0, FLAGS },
91 {"s", "set frame size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str="640x480"}, 0, 0, FLAGS },
92 {"rate", "set frame rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, 0, INT_MAX, FLAGS },
93 {"r", "set frame rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, 0, INT_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
init(AVFilterContext * ctx)122 static av_cold int init(AVFilterContext *ctx)
123 {
124 MBContext *s = ctx->priv;
125
126 s->bailout *= s->bailout;
127
128 s->start_scale /=s->h;
129 s->end_scale /=s->h;
130
131 s->cache_allocated = s->w * s->h * 3;
132 s->cache_used = 0;
133 s->point_cache= av_malloc_array(s->cache_allocated, sizeof(*s->point_cache));
134 s-> next_cache= av_malloc_array(s->cache_allocated, sizeof(*s-> next_cache));
135 s-> zyklus = av_malloc_array(s->maxiter + 16, sizeof(*s->zyklus));
136
137 if (!s->point_cache || !s->next_cache || !s->zyklus)
138 return AVERROR(ENOMEM);
139
140 return 0;
141 }
142
uninit(AVFilterContext * ctx)143 static av_cold void uninit(AVFilterContext *ctx)
144 {
145 MBContext *s = ctx->priv;
146
147 av_freep(&s->point_cache);
148 av_freep(&s-> next_cache);
149 av_freep(&s->zyklus);
150 }
151
config_props(AVFilterLink * outlink)152 static int config_props(AVFilterLink *outlink)
153 {
154 AVFilterContext *ctx = outlink->src;
155 MBContext *s = ctx->priv;
156
157 if (av_image_check_size(s->w, s->h, 0, ctx) < 0)
158 return AVERROR(EINVAL);
159
160 outlink->w = s->w;
161 outlink->h = s->h;
162 outlink->time_base = av_inv_q(s->frame_rate);
163 outlink->frame_rate = s->frame_rate;
164
165 return 0;
166 }
167
fill_from_cache(AVFilterContext * ctx,uint32_t * color,int * in_cidx,int * out_cidx,double py,double scale)168 static void fill_from_cache(AVFilterContext *ctx, uint32_t *color, int *in_cidx, int *out_cidx, double py, double scale){
169 MBContext *s = ctx->priv;
170 if(s->morphamp)
171 return;
172 for(; *in_cidx < s->cache_used; (*in_cidx)++){
173 Point *p= &s->point_cache[*in_cidx];
174 int x;
175 if(p->p[1] > py)
176 break;
177 x= lrint((p->p[0] - s->start_x) / scale + s->w/2);
178 if(x<0 || x >= s->w)
179 continue;
180 if(color) color[x] = p->val;
181 if(out_cidx && *out_cidx < s->cache_allocated)
182 s->next_cache[(*out_cidx)++]= *p;
183 }
184 }
185
interpol(MBContext * s,uint32_t * color,int x,int y,int linesize)186 static int interpol(MBContext *s, uint32_t *color, int x, int y, int linesize)
187 {
188 uint32_t a,b,c,d, i;
189 uint32_t ipol=0xFF000000;
190 int dist;
191
192 if(!x || !y || x+1==s->w || y+1==s->h)
193 return 0;
194
195 dist= FFMAX(FFABS(x-(s->w>>1))*s->h, FFABS(y-(s->h>>1))*s->w);
196
197 if(dist<(s->w*s->h>>3))
198 return 0;
199
200 a=color[(x+1) + (y+0)*linesize];
201 b=color[(x-1) + (y+1)*linesize];
202 c=color[(x+0) + (y+1)*linesize];
203 d=color[(x+1) + (y+1)*linesize];
204
205 if(a&&c){
206 b= color[(x-1) + (y+0)*linesize];
207 d= color[(x+0) + (y-1)*linesize];
208 }else if(b&&d){
209 a= color[(x+1) + (y-1)*linesize];
210 c= color[(x-1) + (y-1)*linesize];
211 }else if(c){
212 d= color[(x+0) + (y-1)*linesize];
213 a= color[(x-1) + (y+0)*linesize];
214 b= color[(x+1) + (y-1)*linesize];
215 }else if(d){
216 c= color[(x-1) + (y-1)*linesize];
217 a= color[(x-1) + (y+0)*linesize];
218 b= color[(x+1) + (y-1)*linesize];
219 }else
220 return 0;
221
222 for(i=0; i<3; i++){
223 int s= 8*i;
224 uint8_t ac= a>>s;
225 uint8_t bc= b>>s;
226 uint8_t cc= c>>s;
227 uint8_t dc= d>>s;
228 int ipolab= (ac + bc);
229 int ipolcd= (cc + dc);
230 if(FFABS(ipolab - ipolcd) > 5)
231 return 0;
232 if(FFABS(ac-bc)+FFABS(cc-dc) > 20)
233 return 0;
234 ipol |= ((ipolab + ipolcd + 2)/4)<<s;
235 }
236 color[x + y*linesize]= ipol;
237 return 1;
238 }
239
draw_mandelbrot(AVFilterContext * ctx,uint32_t * color,int linesize,int64_t pts)240 static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize, int64_t pts)
241 {
242 MBContext *s = ctx->priv;
243 int x,y,i, in_cidx=0, next_cidx=0, tmp_cidx;
244 double scale= s->start_scale*pow(s->end_scale/s->start_scale, pts/s->end_pts);
245 int use_zyklus=0;
246 fill_from_cache(ctx, NULL, &in_cidx, NULL, s->start_y+scale*(-s->h/2-0.5), scale);
247 tmp_cidx= in_cidx;
248 memset(color, 0, sizeof(*color)*s->w);
249 for(y=0; y<s->h; y++){
250 int y1= y+1;
251 const double ci=s->start_y+scale*(y-s->h/2);
252 fill_from_cache(ctx, NULL, &in_cidx, &next_cidx, ci, scale);
253 if(y1<s->h){
254 memset(color+linesize*y1, 0, sizeof(*color)*s->w);
255 fill_from_cache(ctx, color+linesize*y1, &tmp_cidx, NULL, ci + 3*scale/2, scale);
256 }
257
258 for(x=0; x<s->w; x++){
259 float av_uninit(epsilon);
260 const double cr=s->start_x+scale*(x-s->w/2);
261 double zr=cr;
262 double zi=ci;
263 uint32_t c=0;
264 double dv= s->dither / (double)(1LL<<32);
265 s->dither= s->dither*1664525+1013904223;
266
267 if(color[x + y*linesize] & 0xFF000000)
268 continue;
269 if(!s->morphamp){
270 if(interpol(s, color, x, y, linesize)){
271 if(next_cidx < s->cache_allocated){
272 s->next_cache[next_cidx ].p[0]= cr;
273 s->next_cache[next_cidx ].p[1]= ci;
274 s->next_cache[next_cidx++].val = color[x + y*linesize];
275 }
276 continue;
277 }
278 }else{
279 zr += cos(pts * s->morphxf) * s->morphamp;
280 zi += sin(pts * s->morphyf) * s->morphamp;
281 }
282
283 use_zyklus= (x==0 || s->inner!=BLACK ||color[x-1 + y*linesize] == 0xFF000000);
284 if(use_zyklus)
285 epsilon= scale*(abs(x-s->w/2) + abs(y-s->h/2))/s->w;
286
287 #define Z_Z2_C(outr,outi,inr,ini)\
288 outr= inr*inr - ini*ini + cr;\
289 outi= 2*inr*ini + ci;
290
291 #define Z_Z2_C_ZYKLUS(outr,outi,inr,ini, Z)\
292 Z_Z2_C(outr,outi,inr,ini)\
293 if(use_zyklus){\
294 if(Z && fabs(s->zyklus[i>>1][0]-outr)+fabs(s->zyklus[i>>1][1]-outi) <= epsilon)\
295 break;\
296 }\
297 s->zyklus[i][0]= outr;\
298 s->zyklus[i][1]= outi;\
299
300
301
302 for(i=0; i<s->maxiter-8; i++){
303 double t;
304 Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
305 i++;
306 Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
307 i++;
308 Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
309 i++;
310 Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
311 i++;
312 Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
313 i++;
314 Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
315 i++;
316 Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
317 i++;
318 Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
319 if(zr*zr + zi*zi > s->bailout){
320 i-= FFMIN(7, i);
321 for(; i<s->maxiter; i++){
322 zr= s->zyklus[i][0];
323 zi= s->zyklus[i][1];
324 if(zr*zr + zi*zi > s->bailout){
325 switch(s->outer){
326 case ITERATION_COUNT:
327 zr = i;
328 c = lrintf((sinf(zr)+1)*127) + lrintf((sinf(zr/1.234)+1)*127)*256*256 + lrintf((sinf(zr/100)+1)*127)*256;
329 break;
330 case NORMALIZED_ITERATION_COUNT:
331 zr = i + log2(log(s->bailout) / log(zr*zr + zi*zi));
332 c = lrintf((sinf(zr)+1)*127) + lrintf((sinf(zr/1.234)+1)*127)*256*256 + lrintf((sinf(zr/100)+1)*127)*256;
333 break;
334 case WHITE:
335 c = 0xFFFFFF;
336 break;
337 case OUTZ:
338 zr /= s->bailout;
339 zi /= s->bailout;
340 c = (((int)(zr*128+128))&0xFF)*256 + (((int)(zi*128+128))&0xFF);
341 }
342 break;
343 }
344 }
345 break;
346 }
347 }
348 if(!c){
349 if(s->inner==PERIOD){
350 int j;
351 for(j=i-1; j; j--)
352 if(SQR(s->zyklus[j][0]-zr) + SQR(s->zyklus[j][1]-zi) < epsilon*epsilon*10)
353 break;
354 if(j){
355 c= i-j;
356 c= ((c<<5)&0xE0) + ((c<<10)&0xE000) + ((c<<15)&0xE00000);
357 }
358 }else if(s->inner==CONVTIME){
359 c= floor(i*255.0/s->maxiter+dv)*0x010101;
360 } else if(s->inner==MINCOL){
361 int j;
362 double closest=9999;
363 int closest_index=0;
364 for(j=i-1; j>=0; j--)
365 if(SQR(s->zyklus[j][0]) + SQR(s->zyklus[j][1]) < closest){
366 closest= SQR(s->zyklus[j][0]) + SQR(s->zyklus[j][1]);
367 closest_index= j;
368 }
369 closest = sqrt(closest);
370 c= lrintf((s->zyklus[closest_index][0]/closest+1)*127+dv) + lrintf((s->zyklus[closest_index][1]/closest+1)*127+dv)*256;
371 }
372 }
373 c |= 0xFF000000;
374 color[x + y*linesize]= c;
375 if(next_cidx < s->cache_allocated){
376 s->next_cache[next_cidx ].p[0]= cr;
377 s->next_cache[next_cidx ].p[1]= ci;
378 s->next_cache[next_cidx++].val = c;
379 }
380 }
381 fill_from_cache(ctx, NULL, &in_cidx, &next_cidx, ci + scale/2, scale);
382 }
383 FFSWAP(void*, s->next_cache, s->point_cache);
384 s->cache_used = next_cidx;
385 if(s->cache_used == s->cache_allocated)
386 av_log(ctx, AV_LOG_INFO, "Mandelbrot cache is too small!\n");
387 }
388
request_frame(AVFilterLink * link)389 static int request_frame(AVFilterLink *link)
390 {
391 MBContext *s = link->src->priv;
392 AVFrame *picref = ff_get_video_buffer(link, s->w, s->h);
393 if (!picref)
394 return AVERROR(ENOMEM);
395
396 picref->sample_aspect_ratio = (AVRational) {1, 1};
397 picref->pts = s->pts++;
398
399 draw_mandelbrot(link->src, (uint32_t*)picref->data[0], picref->linesize[0]/4, picref->pts);
400 return ff_filter_frame(link, picref);
401 }
402
403 static const AVFilterPad mandelbrot_outputs[] = {
404 {
405 .name = "default",
406 .type = AVMEDIA_TYPE_VIDEO,
407 .request_frame = request_frame,
408 .config_props = config_props,
409 },
410 };
411
412 const AVFilter ff_vsrc_mandelbrot = {
413 .name = "mandelbrot",
414 .description = NULL_IF_CONFIG_SMALL("Render a Mandelbrot fractal."),
415 .priv_size = sizeof(MBContext),
416 .priv_class = &mandelbrot_class,
417 .init = init,
418 .uninit = uninit,
419 .inputs = NULL,
420 FILTER_OUTPUTS(mandelbrot_outputs),
421 FILTER_SINGLE_PIXFMT(AV_PIX_FMT_0BGR32),
422 };
423