2 * Copyright (c) 2011 Michael Niedermayer
4 * This file is part of FFmpeg.
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.
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.
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
20 * The vsrc_color filter from Stefano Sabatini was used as template to create
26 * Mandelbrot fraktal renderer
32 #include "libavutil/imgutils.h"
33 #include "libavutil/opt.h"
34 #include "libavutil/parseutils.h"
38 #define SQR(a) ((a)*(a))
42 NORMALIZED_ITERATION_COUNT,
52 typedef struct Point {
80 #define OFFSET(x) offsetof(MBContext, x)
82 static const AVOption mandelbrot_options[] = {
83 {"size", "set frame size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str="640x480"}, CHAR_MIN, CHAR_MAX },
84 {"s", "set frame size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str="640x480"}, CHAR_MIN, CHAR_MAX },
85 {"rate", "set frame rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str="25"}, CHAR_MIN, CHAR_MAX },
86 {"r", "set frame rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str="25"}, CHAR_MIN, CHAR_MAX },
87 {"maxiter", "set max iterations number", OFFSET(maxiter), AV_OPT_TYPE_INT, {.dbl=7189}, 1, INT_MAX },
88 {"start_x", "set the initial x position", OFFSET(start_x), AV_OPT_TYPE_DOUBLE, {.dbl=-0.743643887037158704752191506114774}, -100, 100 },
89 {"start_y", "set the initial y position", OFFSET(start_y), AV_OPT_TYPE_DOUBLE, {.dbl=-0.131825904205311970493132056385139}, -100, 100 },
90 {"start_scale", "set the initial scale value", OFFSET(start_scale), AV_OPT_TYPE_DOUBLE, {.dbl=3.0}, 0, FLT_MAX },
91 {"end_scale", "set the terminal scale value", OFFSET(end_scale), AV_OPT_TYPE_DOUBLE, {.dbl=0.3}, 0, FLT_MAX },
92 {"end_pts", "set the terminal pts value", OFFSET(end_pts), AV_OPT_TYPE_DOUBLE, {.dbl=400}, 0, INT64_MAX },
93 {"bailout", "set the bailout value", OFFSET(bailout), AV_OPT_TYPE_DOUBLE, {.dbl=10}, 0, FLT_MAX },
95 {"outer", "set outer coloring mode", OFFSET(outer), AV_OPT_TYPE_INT, {.dbl=NORMALIZED_ITERATION_COUNT}, 0, INT_MAX, 0, "outer"},
96 {"iteration_count", "set iteration count mode", 0, AV_OPT_TYPE_CONST, {.dbl=ITERATION_COUNT}, INT_MIN, INT_MAX, 0, "outer" },
97 {"normalized_iteration_count", "set normalized iteration count mode", 0, AV_OPT_TYPE_CONST, {.dbl=NORMALIZED_ITERATION_COUNT}, INT_MIN, INT_MAX, 0, "outer" },
99 {"inner", "set inner coloring mode", OFFSET(inner), AV_OPT_TYPE_INT, {.dbl=MINCOL}, 0, INT_MAX, 0, "inner"},
100 {"black", "set black mode", 0, AV_OPT_TYPE_CONST, {.dbl=BLACK}, INT_MIN, INT_MAX, 0, "inner" },
101 {"period", "set period mode", 0, AV_OPT_TYPE_CONST, {.dbl=PERIOD}, INT_MIN, INT_MAX, 0, "inner" },
102 {"convergence", "show time until convergence", 0, AV_OPT_TYPE_CONST, {.dbl=CONVTIME}, INT_MIN, INT_MAX, 0, "inner" },
103 {"mincol", "color based on point closest to the origin of the iterations", 0, AV_OPT_TYPE_CONST, {.dbl=MINCOL}, INT_MIN, INT_MAX, 0, "inner" },
108 static const AVClass mandelbrot_class = {
109 .class_name = "mandelbrot",
110 .item_name = av_default_item_name,
111 .option = mandelbrot_options,
112 .version = LIBAVUTIL_VERSION_INT,
113 .category = AV_CLASS_CATEGORY_FILTER,
116 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
118 MBContext *mb = ctx->priv;
122 mb->class = &mandelbrot_class;
123 av_opt_set_defaults(mb);
125 if ((err = (av_set_options_string(mb, args, "=", ":"))) < 0) {
126 av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);
129 mb->bailout *= mb->bailout;
131 mb->start_scale /=mb->h;
132 mb->end_scale /=mb->h;
134 if (av_parse_video_rate(&rate_q, mb->rate) < 0 ||
135 rate_q.den <= 0 || rate_q.num <= 0) {
136 av_log(ctx, AV_LOG_ERROR, "Invalid frame rate: %s\n", mb->rate);
137 return AVERROR(EINVAL);
139 mb->time_base.num = rate_q.den;
140 mb->time_base.den = rate_q.num;
142 mb->cache_allocated = mb->w * mb->h * 3;
144 mb->point_cache= av_malloc(sizeof(*mb->point_cache)*mb->cache_allocated);
145 mb-> next_cache= av_malloc(sizeof(*mb-> next_cache)*mb->cache_allocated);
146 mb-> zyklus = av_malloc(sizeof(*mb->zyklus) * (mb->maxiter+16));
151 static av_cold void uninit(AVFilterContext *ctx)
153 MBContext *mb = ctx->priv;
156 av_freep(&mb->point_cache);
157 av_freep(&mb-> next_cache);
158 av_freep(&mb->zyklus);
161 static int query_formats(AVFilterContext *ctx)
163 static const enum PixelFormat pix_fmts[] = {
168 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
172 static int config_props(AVFilterLink *inlink)
174 AVFilterContext *ctx = inlink->src;
175 MBContext *mb = ctx->priv;
177 if (av_image_check_size(mb->w, mb->h, 0, ctx) < 0)
178 return AVERROR(EINVAL);
182 inlink->time_base = mb->time_base;
187 static void fill_from_cache(AVFilterContext *ctx, uint32_t *color, int *in_cidx, int *out_cidx, double py, double scale){
188 MBContext *mb = ctx->priv;
189 for(; *in_cidx < mb->cache_used; (*in_cidx)++){
190 Point *p= &mb->point_cache[*in_cidx];
194 x= round((p->p[0] - mb->start_x) / scale + mb->w/2);
195 if(x<0 || x >= mb->w)
197 if(color) color[x] = p->val;
198 if(out_cidx && *out_cidx < mb->cache_allocated)
199 mb->next_cache[(*out_cidx)++]= *p;
203 static int interpol(MBContext *mb, uint32_t *color, int x, int y, int linesize)
206 uint32_t ipol=0xFF000000;
209 if(!x || !y || x+1==mb->w || y+1==mb->h)
212 dist= FFMAX(FFABS(x-(mb->w>>1))*mb->h, FFABS(y-(mb->h>>1))*mb->w);
214 if(dist<(mb->w*mb->h>>3))
217 a=color[(x+1) + (y+0)*linesize];
218 b=color[(x-1) + (y+1)*linesize];
219 c=color[(x+0) + (y+1)*linesize];
220 d=color[(x+1) + (y+1)*linesize];
223 b= color[(x-1) + (y+0)*linesize];
224 d= color[(x+0) + (y-1)*linesize];
226 a= color[(x+1) + (y-1)*linesize];
227 c= color[(x-1) + (y-1)*linesize];
229 d= color[(x+0) + (y-1)*linesize];
230 a= color[(x-1) + (y+0)*linesize];
231 b= color[(x+1) + (y-1)*linesize];
233 c= color[(x-1) + (y-1)*linesize];
234 a= color[(x-1) + (y+0)*linesize];
235 b= color[(x+1) + (y-1)*linesize];
245 int ipolab= (ac + bc);
246 int ipolcd= (cc + dc);
247 if(FFABS(ipolab - ipolcd) > 5)
249 if(FFABS(ac-bc)+FFABS(cc-dc) > 20)
251 ipol |= ((ipolab + ipolcd + 2)/4)<<s;
253 color[x + y*linesize]= ipol;
257 static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize, int64_t pts)
259 MBContext *mb = ctx->priv;
260 int x,y,i, in_cidx=0, next_cidx=0, tmp_cidx;
261 double scale= mb->start_scale*pow(mb->end_scale/mb->start_scale, pts/mb->end_pts);
263 fill_from_cache(ctx, NULL, &in_cidx, NULL, mb->start_y+scale*(-mb->h/2-0.5), scale);
265 memset(color, 0, sizeof(*color)*mb->w);
266 for(y=0; y<mb->h; y++){
268 const double ci=mb->start_y+scale*(y-mb->h/2);
269 fill_from_cache(ctx, NULL, &in_cidx, &next_cidx, ci, scale);
271 memset(color+linesize*y1, 0, sizeof(*color)*mb->w);
272 fill_from_cache(ctx, color+linesize*y1, &tmp_cidx, NULL, ci + 3*scale/2, scale);
275 for(x=0; x<mb->w; x++){
276 float av_uninit(epsilon);
277 const double cr=mb->start_x+scale*(x-mb->w/2);
281 double dv= mb->dither / (double)(1LL<<32);
282 mb->dither= mb->dither*1664525+1013904223;
284 if(color[x + y*linesize] & 0xFF000000)
286 if(interpol(mb, color, x, y, linesize)){
287 if(next_cidx < mb->cache_allocated){
288 mb->next_cache[next_cidx ].p[0]= cr;
289 mb->next_cache[next_cidx ].p[1]= ci;
290 mb->next_cache[next_cidx++].val = color[x + y*linesize];
295 use_zyklus= (x==0 || mb->inner!=BLACK ||color[x-1 + y*linesize] == 0xFF000000);
297 epsilon= scale*1*sqrt(SQR(x-mb->w/2) + SQR(y-mb->h/2))/mb->w;
299 #define Z_Z2_C(outr,outi,inr,ini)\
300 outr= inr*inr - ini*ini + cr;\
301 outi= 2*inr*ini + ci;
303 #define Z_Z2_C_ZYKLUS(outr,outi,inr,ini, Z)\
304 Z_Z2_C(outr,outi,inr,ini)\
306 if(Z && fabs(mb->zyklus[i>>1][0]-outr)+fabs(mb->zyklus[i>>1][1]-outi) <= epsilon)\
309 mb->zyklus[i][0]= outr;\
310 mb->zyklus[i][1]= outi;\
314 for(i=0; i<mb->maxiter-8; i++){
316 Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
318 Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
320 Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
322 Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
324 Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
326 Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
328 Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
330 Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
331 if(zr*zr + zi*zi > mb->bailout){
333 for(; i<mb->maxiter; i++){
334 zr= mb->zyklus[i][0];
335 zi= mb->zyklus[i][1];
336 if(zr*zr + zi*zi > mb->bailout){
338 case ITERATION_COUNT: zr = i; break;
339 case NORMALIZED_ITERATION_COUNT: zr= i + log2(log(mb->bailout) / log(zr*zr + zi*zi)); break;
341 c= lrintf((sin(zr)+1)*127) + lrintf((sin(zr/1.234)+1)*127)*256*256 + lrintf((sin(zr/100)+1)*127)*256;
349 if(mb->inner==PERIOD){
352 if(SQR(mb->zyklus[j][0]-zr) + SQR(mb->zyklus[j][1]-zi) < epsilon*epsilon*10)
356 c= ((c<<5)&0xE0) + ((c<<16)&0xE000) + ((c<<27)&0xE00000);
358 }else if(mb->inner==CONVTIME){
359 c= floor(i*255.0/mb->maxiter+dv)*0x010101;
360 } else if(mb->inner==MINCOL){
364 for(j=i-1; j>=0; j--)
365 if(SQR(mb->zyklus[j][0]) + SQR(mb->zyklus[j][1]) < closest){
366 closest= SQR(mb->zyklus[j][0]) + SQR(mb->zyklus[j][1]);
369 closest = sqrt(closest);
370 c= lrintf((mb->zyklus[closest_index][0]/closest+1)*127+dv) + lrintf((mb->zyklus[closest_index][1]/closest+1)*127+dv)*256;
374 color[x + y*linesize]= c;
375 if(next_cidx < mb->cache_allocated){
376 mb->next_cache[next_cidx ].p[0]= cr;
377 mb->next_cache[next_cidx ].p[1]= ci;
378 mb->next_cache[next_cidx++].val = c;
381 fill_from_cache(ctx, NULL, &in_cidx, &next_cidx, ci + scale/2, scale);
383 FFSWAP(void*, mb->next_cache, mb->point_cache);
384 mb->cache_used = next_cidx;
385 if(mb->cache_used == mb->cache_allocated)
386 av_log(0, AV_LOG_INFO, "Mandelbrot cache is too small!\n");
389 static int request_frame(AVFilterLink *link)
391 MBContext *mb = link->src->priv;
392 AVFilterBufferRef *picref = ff_get_video_buffer(link, AV_PERM_WRITE, mb->w, mb->h);
393 picref->video->sample_aspect_ratio = (AVRational) {1, 1};
394 picref->pts = mb->pts++;
397 ff_start_frame(link, avfilter_ref_buffer(picref, ~0));
398 draw_mandelbrot(link->src, (uint32_t*)picref->data[0], picref->linesize[0]/4, picref->pts);
399 ff_draw_slice(link, 0, mb->h, 1);
401 avfilter_unref_buffer(picref);
406 AVFilter avfilter_vsrc_mandelbrot = {
407 .name = "mandelbrot",
408 .description = NULL_IF_CONFIG_SMALL("Render a Mandelbrot fractal."),
410 .priv_size = sizeof(MBContext),
414 .query_formats = query_formats,
416 .inputs = (const AVFilterPad[]) {{ .name = NULL}},
418 .outputs = (const AVFilterPad[]) {{ .name = "default",
419 .type = AVMEDIA_TYPE_VIDEO,
420 .request_frame = request_frame,
421 .config_props = config_props },