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
30 #include "libavutil/imgutils.h"
31 #include "libavutil/parseutils.h"
35 NORMALIZED_ITERATION_COUNT,
38 typedef struct Point {
62 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
64 MBContext *mb = ctx->priv;
65 char frame_size [128] = "640x480";
66 char frame_rate [128] = "25";
67 AVRational frame_rate_q;
71 mb->start_x=-0.743643887037158704752191506114774;
72 mb->start_y=-0.131825904205311970493132056385139;
77 mb->outer= NORMALIZED_ITERATION_COUNT;
79 sscanf(args, "%127[^:]:%127[^:]:%d:%lf:%lf:%lf:%lf:%lf:%lf:%d", frame_size, frame_rate,
80 &mb->maxiter, &mb->start_x, &mb->start_y, &mb->start_scale, &mb->end_scale,
81 &mb->end_pts, &mb->bailout, &mb->outer);
82 mb->bailout *= mb->bailout;
84 if (av_parse_video_size(&mb->w, &mb->h, frame_size) < 0) {
85 av_log(ctx, AV_LOG_ERROR, "Invalid frame size: %s\n", frame_size);
86 return AVERROR(EINVAL);
88 mb->start_scale /=mb->h;
89 mb->end_scale /=mb->h;
91 if (av_parse_video_rate(&frame_rate_q, frame_rate) < 0 ||
92 frame_rate_q.den <= 0 || frame_rate_q.num <= 0) {
93 av_log(ctx, AV_LOG_ERROR, "Invalid frame rate: %s\n", frame_rate);
94 return AVERROR(EINVAL);
96 mb->time_base.num = frame_rate_q.den;
97 mb->time_base.den = frame_rate_q.num;
99 mb->cache_allocated = mb->w * mb->h * 3;
101 mb->point_cache= av_malloc(sizeof(*mb->point_cache)*mb->cache_allocated);
102 mb-> next_cache= av_malloc(sizeof(*mb-> next_cache)*mb->cache_allocated);
103 mb-> zyklus = av_malloc(sizeof(*mb->zyklus) * mb->maxiter);
108 static av_cold void uninit(AVFilterContext *ctx)
110 MBContext *mb = ctx->priv;
113 av_freep(&mb->point_cache);
114 av_freep(&mb-> next_cache);
115 av_freep(&mb->zyklus);
118 static int query_formats(AVFilterContext *ctx)
120 static const enum PixelFormat pix_fmts[] = {
125 avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));
129 static int config_props(AVFilterLink *inlink)
131 AVFilterContext *ctx = inlink->src;
132 MBContext *mb = ctx->priv;
134 if (av_image_check_size(mb->w, mb->h, 0, ctx) < 0)
135 return AVERROR(EINVAL);
139 inlink->time_base = mb->time_base;
144 static void fill_from_cache(AVFilterContext *ctx, uint32_t *color, int *in_cidx, int *out_cidx, double py, double scale){
145 MBContext *mb = ctx->priv;
146 for(; *in_cidx < mb->cache_used; (*in_cidx)++){
147 Point *p= &mb->point_cache[*in_cidx];
149 if(*in_cidx >= mb->cache_used || p->p[1] > py)
151 x= round((p->p[0] - mb->start_x) / scale + mb->w/2);
152 if(x<0 || x >= mb->w)
154 if(color) color[x] = p->val;
155 if(out_cidx && *out_cidx < mb->cache_allocated)
156 mb->next_cache[(*out_cidx)++]= *p;
160 static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize, int64_t pts)
162 MBContext *mb = ctx->priv;
163 int x,y,i, in_cidx=0, next_cidx=0, tmp_cidx;
164 double scale= mb->start_scale*pow(mb->end_scale/mb->start_scale, pts/mb->end_pts);
166 fill_from_cache(ctx, NULL, &in_cidx, NULL, mb->start_y+scale*(-mb->h/2-0.5), scale);
167 for(y=0; y<mb->h; y++){
168 const double ci=mb->start_y+scale*(y-mb->h/2);
169 memset(color+linesize*y, 0, sizeof(*color)*mb->w);
170 fill_from_cache(ctx, color+linesize*y, &in_cidx, &next_cidx, ci, scale);
172 fill_from_cache(ctx, color+linesize*y, &tmp_cidx, NULL, ci + scale/2, scale);
174 for(x=0; x<mb->w; x++){
175 const double cr=mb->start_x+scale*(x-mb->w/2);
180 if(color[x + y*linesize] & 0xFF000000)
183 for(i=0; i<mb->maxiter; i++){
185 if(zr*zr + zi*zi > mb->bailout){
187 case ITERATION_COUNT: zr= i; break;
188 case NORMALIZED_ITERATION_COUNT: zr= i + (log(log(mb->bailout)) - log(log(sqrt(zr*zr + zi*zi))))/log(2); break;
190 c= lrintf((sin(zr)+1)*127) + lrintf((sin(zr/1.234)+1)*127)*256*256 + lrintf((sin(zr/100)+1)*127)*256;
197 if(i && mb->zyklus[i>>1][0]==zr && mb->zyklus[i>>1][1]==zi)
199 mb->zyklus[i][0]= zr;
200 mb->zyklus[i][1]= zi;
205 color[x + y*linesize]= c;
206 if(next_cidx < mb->cache_allocated){
207 mb->next_cache[next_cidx ].p[0]= cr;
208 mb->next_cache[next_cidx ].p[1]= ci;
209 mb->next_cache[next_cidx++].val = c;
212 fill_from_cache(ctx, NULL, &in_cidx, &next_cidx, ci + scale/2, scale);
214 FFSWAP(void*, mb->next_cache, mb->point_cache);
215 mb->cache_used = next_cidx;
216 if(mb->cache_used == mb->cache_allocated)
217 av_log(0, AV_LOG_INFO, "Mandelbrot cache is too small!\n");
220 static int request_frame(AVFilterLink *link)
222 MBContext *mb = link->src->priv;
223 AVFilterBufferRef *picref = avfilter_get_video_buffer(link, AV_PERM_WRITE, mb->w, mb->h);
224 picref->video->sample_aspect_ratio = (AVRational) {1, 1};
225 picref->pts = mb->pts++;
228 avfilter_start_frame(link, avfilter_ref_buffer(picref, ~0));
229 draw_mandelbrot(link->src, picref->data[0], picref->linesize[0]/4, picref->pts);
230 avfilter_draw_slice(link, 0, mb->h, 1);
231 avfilter_end_frame(link);
232 avfilter_unref_buffer(picref);
237 AVFilter avfilter_vsrc_mandelbrot = {
238 .name = "mandelbrot",
239 .description = NULL_IF_CONFIG_SMALL("Mandelbrot renderer"),
241 .priv_size = sizeof(MBContext),
245 .query_formats = query_formats,
247 .inputs = (const AVFilterPad[]) {{ .name = NULL}},
249 .outputs = (const AVFilterPad[]) {{ .name = "default",
250 .type = AVMEDIA_TYPE_VIDEO,
251 .request_frame = request_frame,
252 .config_props = config_props },