summaryrefslogtreecommitdiff
path: root/libavfilter/vsrc_mandelbrot.c (plain)
blob: 2f6944f02fd7aa79607cbc3ee2f70ad472ee5c27
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
41enum Outer{
42 ITERATION_COUNT,
43 NORMALIZED_ITERATION_COUNT,
44 WHITE,
45 OUTZ,
46};
47
48enum Inner{
49 BLACK,
50 PERIOD,
51 CONVTIME,
52 MINCOL,
53};
54
55typedef struct Point {
56 double p[2];
57 uint32_t val;
58} Point;
59
60typedef 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 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
89static 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
120AVFILTER_DEFINE_CLASS(mandelbrot);
121
122static 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 return 0;
138}
139
140static av_cold void uninit(AVFilterContext *ctx)
141{
142 MBContext *s = ctx->priv;
143
144 av_freep(&s->point_cache);
145 av_freep(&s-> next_cache);
146 av_freep(&s->zyklus);
147}
148
149static int query_formats(AVFilterContext *ctx)
150{
151 static const enum AVPixelFormat pix_fmts[] = {
152 AV_PIX_FMT_0BGR32,
153 AV_PIX_FMT_NONE
154 };
155
156 AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
157 if (!fmts_list)
158 return AVERROR(ENOMEM);
159 return ff_set_common_formats(ctx, fmts_list);
160}
161
162static int config_props(AVFilterLink *inlink)
163{
164 AVFilterContext *ctx = inlink->src;
165 MBContext *s = ctx->priv;
166
167 if (av_image_check_size(s->w, s->h, 0, ctx) < 0)
168 return AVERROR(EINVAL);
169
170 inlink->w = s->w;
171 inlink->h = s->h;
172 inlink->time_base = av_inv_q(s->frame_rate);
173
174 return 0;
175}
176
177static void fill_from_cache(AVFilterContext *ctx, uint32_t *color, int *in_cidx, int *out_cidx, double py, double scale){
178 MBContext *s = ctx->priv;
179 if(s->morphamp)
180 return;
181 for(; *in_cidx < s->cache_used; (*in_cidx)++){
182 Point *p= &s->point_cache[*in_cidx];
183 int x;
184 if(p->p[1] > py)
185 break;
186 x= lrint((p->p[0] - s->start_x) / scale + s->w/2);
187 if(x<0 || x >= s->w)
188 continue;
189 if(color) color[x] = p->val;
190 if(out_cidx && *out_cidx < s->cache_allocated)
191 s->next_cache[(*out_cidx)++]= *p;
192 }
193}
194
195static int interpol(MBContext *s, uint32_t *color, int x, int y, int linesize)
196{
197 uint32_t a,b,c,d, i;
198 uint32_t ipol=0xFF000000;
199 int dist;
200
201 if(!x || !y || x+1==s->w || y+1==s->h)
202 return 0;
203
204 dist= FFMAX(FFABS(x-(s->w>>1))*s->h, FFABS(y-(s->h>>1))*s->w);
205
206 if(dist<(s->w*s->h>>3))
207 return 0;
208
209 a=color[(x+1) + (y+0)*linesize];
210 b=color[(x-1) + (y+1)*linesize];
211 c=color[(x+0) + (y+1)*linesize];
212 d=color[(x+1) + (y+1)*linesize];
213
214 if(a&&c){
215 b= color[(x-1) + (y+0)*linesize];
216 d= color[(x+0) + (y-1)*linesize];
217 }else if(b&&d){
218 a= color[(x+1) + (y-1)*linesize];
219 c= color[(x-1) + (y-1)*linesize];
220 }else if(c){
221 d= color[(x+0) + (y-1)*linesize];
222 a= color[(x-1) + (y+0)*linesize];
223 b= color[(x+1) + (y-1)*linesize];
224 }else if(d){
225 c= color[(x-1) + (y-1)*linesize];
226 a= color[(x-1) + (y+0)*linesize];
227 b= color[(x+1) + (y-1)*linesize];
228 }else
229 return 0;
230
231 for(i=0; i<3; i++){
232 int s= 8*i;
233 uint8_t ac= a>>s;
234 uint8_t bc= b>>s;
235 uint8_t cc= c>>s;
236 uint8_t dc= d>>s;
237 int ipolab= (ac + bc);
238 int ipolcd= (cc + dc);
239 if(FFABS(ipolab - ipolcd) > 5)
240 return 0;
241 if(FFABS(ac-bc)+FFABS(cc-dc) > 20)
242 return 0;
243 ipol |= ((ipolab + ipolcd + 2)/4)<<s;
244 }
245 color[x + y*linesize]= ipol;
246 return 1;
247}
248
249static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize, int64_t pts)
250{
251 MBContext *s = ctx->priv;
252 int x,y,i, in_cidx=0, next_cidx=0, tmp_cidx;
253 double scale= s->start_scale*pow(s->end_scale/s->start_scale, pts/s->end_pts);
254 int use_zyklus=0;
255 fill_from_cache(ctx, NULL, &in_cidx, NULL, s->start_y+scale*(-s->h/2-0.5), scale);
256 tmp_cidx= in_cidx;
257 memset(color, 0, sizeof(*color)*s->w);
258 for(y=0; y<s->h; y++){
259 int y1= y+1;
260 const double ci=s->start_y+scale*(y-s->h/2);
261 fill_from_cache(ctx, NULL, &in_cidx, &next_cidx, ci, scale);
262 if(y1<s->h){
263 memset(color+linesize*y1, 0, sizeof(*color)*s->w);
264 fill_from_cache(ctx, color+linesize*y1, &tmp_cidx, NULL, ci + 3*scale/2, scale);
265 }
266
267 for(x=0; x<s->w; x++){
268 float av_uninit(epsilon);
269 const double cr=s->start_x+scale*(x-s->w/2);
270 double zr=cr;
271 double zi=ci;
272 uint32_t c=0;
273 double dv= s->dither / (double)(1LL<<32);
274 s->dither= s->dither*1664525+1013904223;
275
276 if(color[x + y*linesize] & 0xFF000000)
277 continue;
278 if(!s->morphamp){
279 if(interpol(s, color, x, y, linesize)){
280 if(next_cidx < s->cache_allocated){
281 s->next_cache[next_cidx ].p[0]= cr;
282 s->next_cache[next_cidx ].p[1]= ci;
283 s->next_cache[next_cidx++].val = color[x + y*linesize];
284 }
285 continue;
286 }
287 }else{
288 zr += cos(pts * s->morphxf) * s->morphamp;
289 zi += sin(pts * s->morphyf) * s->morphamp;
290 }
291
292 use_zyklus= (x==0 || s->inner!=BLACK ||color[x-1 + y*linesize] == 0xFF000000);
293 if(use_zyklus)
294 epsilon= scale*(abs(x-s->w/2) + abs(y-s->h/2))/s->w;
295
296#define Z_Z2_C(outr,outi,inr,ini)\
297 outr= inr*inr - ini*ini + cr;\
298 outi= 2*inr*ini + ci;
299
300#define Z_Z2_C_ZYKLUS(outr,outi,inr,ini, Z)\
301 Z_Z2_C(outr,outi,inr,ini)\
302 if(use_zyklus){\
303 if(Z && fabs(s->zyklus[i>>1][0]-outr)+fabs(s->zyklus[i>>1][1]-outi) <= epsilon)\
304 break;\
305 }\
306 s->zyklus[i][0]= outr;\
307 s->zyklus[i][1]= outi;\
308
309
310
311 for(i=0; i<s->maxiter-8; i++){
312 double t;
313 Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
314 i++;
315 Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
316 i++;
317 Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
318 i++;
319 Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
320 i++;
321 Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
322 i++;
323 Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
324 i++;
325 Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
326 i++;
327 Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
328 if(zr*zr + zi*zi > s->bailout){
329 i-= FFMIN(7, i);
330 for(; i<s->maxiter; i++){
331 zr= s->zyklus[i][0];
332 zi= s->zyklus[i][1];
333 if(zr*zr + zi*zi > s->bailout){
334 switch(s->outer){
335 case ITERATION_COUNT:
336 zr = i;
337 c = lrintf((sinf(zr)+1)*127) + lrintf((sinf(zr/1.234)+1)*127)*256*256 + lrintf((sinf(zr/100)+1)*127)*256;
338 break;
339 case NORMALIZED_ITERATION_COUNT:
340 zr = i + log2(log(s->bailout) / log(zr*zr + zi*zi));
341 c = lrintf((sinf(zr)+1)*127) + lrintf((sinf(zr/1.234)+1)*127)*256*256 + lrintf((sinf(zr/100)+1)*127)*256;
342 break;
343 case WHITE:
344 c = 0xFFFFFF;
345 break;
346 case OUTZ:
347 zr /= s->bailout;
348 zi /= s->bailout;
349 c = (((int)(zr*128+128))&0xFF)*256 + (((int)(zi*128+128))&0xFF);
350 }
351 break;
352 }
353 }
354 break;
355 }
356 }
357 if(!c){
358 if(s->inner==PERIOD){
359 int j;
360 for(j=i-1; j; j--)
361 if(SQR(s->zyklus[j][0]-zr) + SQR(s->zyklus[j][1]-zi) < epsilon*epsilon*10)
362 break;
363 if(j){
364 c= i-j;
365 c= ((c<<5)&0xE0) + ((c<<10)&0xE000) + ((c<<15)&0xE00000);
366 }
367 }else if(s->inner==CONVTIME){
368 c= floor(i*255.0/s->maxiter+dv)*0x010101;
369 } else if(s->inner==MINCOL){
370 int j;
371 double closest=9999;
372 int closest_index=0;
373 for(j=i-1; j>=0; j--)
374 if(SQR(s->zyklus[j][0]) + SQR(s->zyklus[j][1]) < closest){
375 closest= SQR(s->zyklus[j][0]) + SQR(s->zyklus[j][1]);
376 closest_index= j;
377 }
378 closest = sqrt(closest);
379 c= lrintf((s->zyklus[closest_index][0]/closest+1)*127+dv) + lrintf((s->zyklus[closest_index][1]/closest+1)*127+dv)*256;
380 }
381 }
382 c |= 0xFF000000;
383 color[x + y*linesize]= c;
384 if(next_cidx < s->cache_allocated){
385 s->next_cache[next_cidx ].p[0]= cr;
386 s->next_cache[next_cidx ].p[1]= ci;
387 s->next_cache[next_cidx++].val = c;
388 }
389 }
390 fill_from_cache(ctx, NULL, &in_cidx, &next_cidx, ci + scale/2, scale);
391 }
392 FFSWAP(void*, s->next_cache, s->point_cache);
393 s->cache_used = next_cidx;
394 if(s->cache_used == s->cache_allocated)
395 av_log(ctx, AV_LOG_INFO, "Mandelbrot cache is too small!\n");
396}
397
398static int request_frame(AVFilterLink *link)
399{
400 MBContext *s = link->src->priv;
401 AVFrame *picref = ff_get_video_buffer(link, s->w, s->h);
402 if (!picref)
403 return AVERROR(ENOMEM);
404
405 picref->sample_aspect_ratio = (AVRational) {1, 1};
406 picref->pts = s->pts++;
407
408 draw_mandelbrot(link->src, (uint32_t*)picref->data[0], picref->linesize[0]/4, picref->pts);
409 return ff_filter_frame(link, picref);
410}
411
412static const AVFilterPad mandelbrot_outputs[] = {
413 {
414 .name = "default",
415 .type = AVMEDIA_TYPE_VIDEO,
416 .request_frame = request_frame,
417 .config_props = config_props,
418 },
419 { NULL }
420};
421
422AVFilter ff_vsrc_mandelbrot = {
423 .name = "mandelbrot",
424 .description = NULL_IF_CONFIG_SMALL("Render a Mandelbrot fractal."),
425 .priv_size = sizeof(MBContext),
426 .priv_class = &mandelbrot_class,
427 .init = init,
428 .uninit = uninit,
429 .query_formats = query_formats,
430 .inputs = NULL,
431 .outputs = mandelbrot_outputs,
432};
433
generated by cgit at 2024-05-17 03:09:16 (GMT)