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/*
* Copyright (c) 2011 Michael Niedermayer
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* The vsrc_color filter from Stefano Sabatini was used as template to create
* this
*/
/**
* @file
* Mandelbrot fraktal renderer
*/
#include "avfilter.h"
#include "formats.h"
#include "video.h"
#include "internal.h"
#include "libavutil/imgutils.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include <float.h>
#include <math.h>
#define SQR(a) ((a)*(a))
enum Outer{
ITERATION_COUNT,
NORMALIZED_ITERATION_COUNT,
};
enum Inner{
BLACK,
PERIOD,
CONVTIME,
MINCOL,
};
typedef struct Point {
double p[2];
uint32_t val;
} Point;
typedef struct {
const AVClass *class;
int w, h;
AVRational time_base;
uint64_t pts;
char *rate;
int maxiter;
double start_x;
double start_y;
double start_scale;
double end_scale;
double end_pts;
double bailout;
enum Outer outer;
enum Inner inner;
int cache_allocated;
int cache_used;
Point *point_cache;
Point *next_cache;
double (*zyklus)[2];
uint32_t dither;
} MBContext;
#define OFFSET(x) offsetof(MBContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption mandelbrot_options[] = {
{"size", "set frame size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str="640x480"}, CHAR_MIN, CHAR_MAX, FLAGS },
{"s", "set frame size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str="640x480"}, CHAR_MIN, CHAR_MAX, FLAGS },
{"rate", "set frame rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str="25"}, CHAR_MIN, CHAR_MAX, FLAGS },
{"r", "set frame rate", OFFSET(rate), AV_OPT_TYPE_STRING, {.str="25"}, CHAR_MIN, CHAR_MAX, FLAGS },
{"maxiter", "set max iterations number", OFFSET(maxiter), AV_OPT_TYPE_INT, {.i64=7189}, 1, INT_MAX, FLAGS },
{"start_x", "set the initial x position", OFFSET(start_x), AV_OPT_TYPE_DOUBLE, {.dbl=-0.743643887037158704752191506114774}, -100, 100, FLAGS },
{"start_y", "set the initial y position", OFFSET(start_y), AV_OPT_TYPE_DOUBLE, {.dbl=-0.131825904205311970493132056385139}, -100, 100, FLAGS },
{"start_scale", "set the initial scale value", OFFSET(start_scale), AV_OPT_TYPE_DOUBLE, {.dbl=3.0}, 0, FLT_MAX, FLAGS },
{"end_scale", "set the terminal scale value", OFFSET(end_scale), AV_OPT_TYPE_DOUBLE, {.dbl=0.3}, 0, FLT_MAX, FLAGS },
{"end_pts", "set the terminal pts value", OFFSET(end_pts), AV_OPT_TYPE_DOUBLE, {.dbl=400}, 0, INT64_MAX, FLAGS },
{"bailout", "set the bailout value", OFFSET(bailout), AV_OPT_TYPE_DOUBLE, {.dbl=10}, 0, FLT_MAX, FLAGS },
{"outer", "set outer coloring mode", OFFSET(outer), AV_OPT_TYPE_INT, {.i64=NORMALIZED_ITERATION_COUNT}, 0, INT_MAX, FLAGS, "outer" },
{"iteration_count", "set iteration count mode", 0, AV_OPT_TYPE_CONST, {.i64=ITERATION_COUNT}, INT_MIN, INT_MAX, FLAGS, "outer" },
{"normalized_iteration_count", "set normalized iteration count mode", 0, AV_OPT_TYPE_CONST, {.i64=NORMALIZED_ITERATION_COUNT}, INT_MIN, INT_MAX, FLAGS, "outer" },
{"inner", "set inner coloring mode", OFFSET(inner), AV_OPT_TYPE_INT, {.i64=MINCOL}, 0, INT_MAX, FLAGS, "inner" },
{"black", "set black mode", 0, AV_OPT_TYPE_CONST, {.i64=BLACK}, INT_MIN, INT_MAX, FLAGS, "inner"},
{"period", "set period mode", 0, AV_OPT_TYPE_CONST, {.i64=PERIOD}, INT_MIN, INT_MAX, FLAGS, "inner"},
{"convergence", "show time until convergence", 0, AV_OPT_TYPE_CONST, {.i64=CONVTIME}, INT_MIN, INT_MAX, FLAGS, "inner"},
{"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"},
{NULL},
};
AVFILTER_DEFINE_CLASS(mandelbrot);
static av_cold int init(AVFilterContext *ctx, const char *args)
{
MBContext *mb = ctx->priv;
AVRational rate_q;
int err;
mb->class = &mandelbrot_class;
av_opt_set_defaults(mb);
if ((err = (av_set_options_string(mb, args, "=", ":"))) < 0)
return err;
mb->bailout *= mb->bailout;
mb->start_scale /=mb->h;
mb->end_scale /=mb->h;
if (av_parse_video_rate(&rate_q, mb->rate) < 0) {
av_log(ctx, AV_LOG_ERROR, "Invalid frame rate: %s\n", mb->rate);
return AVERROR(EINVAL);
}
mb->time_base.num = rate_q.den;
mb->time_base.den = rate_q.num;
mb->cache_allocated = mb->w * mb->h * 3;
mb->cache_used = 0;
mb->point_cache= av_malloc(sizeof(*mb->point_cache)*mb->cache_allocated);
mb-> next_cache= av_malloc(sizeof(*mb-> next_cache)*mb->cache_allocated);
mb-> zyklus = av_malloc(sizeof(*mb->zyklus) * (mb->maxiter+16));
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
MBContext *mb = ctx->priv;
av_freep(&mb->rate);
av_freep(&mb->point_cache);
av_freep(&mb-> next_cache);
av_freep(&mb->zyklus);
}
static int query_formats(AVFilterContext *ctx)
{
static const enum PixelFormat pix_fmts[] = {
PIX_FMT_BGR32,
PIX_FMT_NONE
};
ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
return 0;
}
static int config_props(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->src;
MBContext *mb = ctx->priv;
if (av_image_check_size(mb->w, mb->h, 0, ctx) < 0)
return AVERROR(EINVAL);
inlink->w = mb->w;
inlink->h = mb->h;
inlink->time_base = mb->time_base;
return 0;
}
static void fill_from_cache(AVFilterContext *ctx, uint32_t *color, int *in_cidx, int *out_cidx, double py, double scale){
MBContext *mb = ctx->priv;
for(; *in_cidx < mb->cache_used; (*in_cidx)++){
Point *p= &mb->point_cache[*in_cidx];
int x;
if(p->p[1] > py)
break;
x= round((p->p[0] - mb->start_x) / scale + mb->w/2);
if(x<0 || x >= mb->w)
continue;
if(color) color[x] = p->val;
if(out_cidx && *out_cidx < mb->cache_allocated)
mb->next_cache[(*out_cidx)++]= *p;
}
}
static int interpol(MBContext *mb, uint32_t *color, int x, int y, int linesize)
{
uint32_t a,b,c,d, i;
uint32_t ipol=0xFF000000;
int dist;
if(!x || !y || x+1==mb->w || y+1==mb->h)
return 0;
dist= FFMAX(FFABS(x-(mb->w>>1))*mb->h, FFABS(y-(mb->h>>1))*mb->w);
if(dist<(mb->w*mb->h>>3))
return 0;
a=color[(x+1) + (y+0)*linesize];
b=color[(x-1) + (y+1)*linesize];
c=color[(x+0) + (y+1)*linesize];
d=color[(x+1) + (y+1)*linesize];
if(a&&c){
b= color[(x-1) + (y+0)*linesize];
d= color[(x+0) + (y-1)*linesize];
}else if(b&&d){
a= color[(x+1) + (y-1)*linesize];
c= color[(x-1) + (y-1)*linesize];
}else if(c){
d= color[(x+0) + (y-1)*linesize];
a= color[(x-1) + (y+0)*linesize];
b= color[(x+1) + (y-1)*linesize];
}else if(d){
c= color[(x-1) + (y-1)*linesize];
a= color[(x-1) + (y+0)*linesize];
b= color[(x+1) + (y-1)*linesize];
}else
return 0;
for(i=0; i<3; i++){
int s= 8*i;
uint8_t ac= a>>s;
uint8_t bc= b>>s;
uint8_t cc= c>>s;
uint8_t dc= d>>s;
int ipolab= (ac + bc);
int ipolcd= (cc + dc);
if(FFABS(ipolab - ipolcd) > 5)
return 0;
if(FFABS(ac-bc)+FFABS(cc-dc) > 20)
return 0;
ipol |= ((ipolab + ipolcd + 2)/4)<<s;
}
color[x + y*linesize]= ipol;
return 1;
}
static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize, int64_t pts)
{
MBContext *mb = ctx->priv;
int x,y,i, in_cidx=0, next_cidx=0, tmp_cidx;
double scale= mb->start_scale*pow(mb->end_scale/mb->start_scale, pts/mb->end_pts);
int use_zyklus=0;
fill_from_cache(ctx, NULL, &in_cidx, NULL, mb->start_y+scale*(-mb->h/2-0.5), scale);
tmp_cidx= in_cidx;
memset(color, 0, sizeof(*color)*mb->w);
for(y=0; y<mb->h; y++){
int y1= y+1;
const double ci=mb->start_y+scale*(y-mb->h/2);
fill_from_cache(ctx, NULL, &in_cidx, &next_cidx, ci, scale);
if(y1<mb->h){
memset(color+linesize*y1, 0, sizeof(*color)*mb->w);
fill_from_cache(ctx, color+linesize*y1, &tmp_cidx, NULL, ci + 3*scale/2, scale);
}
for(x=0; x<mb->w; x++){
float av_uninit(epsilon);
const double cr=mb->start_x+scale*(x-mb->w/2);
double zr=cr;
double zi=ci;
uint32_t c=0;
double dv= mb->dither / (double)(1LL<<32);
mb->dither= mb->dither*1664525+1013904223;
if(color[x + y*linesize] & 0xFF000000)
continue;
if(interpol(mb, color, x, y, linesize)){
if(next_cidx < mb->cache_allocated){
mb->next_cache[next_cidx ].p[0]= cr;
mb->next_cache[next_cidx ].p[1]= ci;
mb->next_cache[next_cidx++].val = color[x + y*linesize];
}
continue;
}
use_zyklus= (x==0 || mb->inner!=BLACK ||color[x-1 + y*linesize] == 0xFF000000);
if(use_zyklus)
epsilon= scale*1*sqrt(SQR(x-mb->w/2) + SQR(y-mb->h/2))/mb->w;
#define Z_Z2_C(outr,outi,inr,ini)\
outr= inr*inr - ini*ini + cr;\
outi= 2*inr*ini + ci;
#define Z_Z2_C_ZYKLUS(outr,outi,inr,ini, Z)\
Z_Z2_C(outr,outi,inr,ini)\
if(use_zyklus){\
if(Z && fabs(mb->zyklus[i>>1][0]-outr)+fabs(mb->zyklus[i>>1][1]-outi) <= epsilon)\
break;\
}\
mb->zyklus[i][0]= outr;\
mb->zyklus[i][1]= outi;\
for(i=0; i<mb->maxiter-8; i++){
double t;
Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
i++;
Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
i++;
Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
i++;
Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
i++;
Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
i++;
Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
i++;
Z_Z2_C_ZYKLUS(t, zi, zr, zi, 0)
i++;
Z_Z2_C_ZYKLUS(zr, zi, t, zi, 1)
if(zr*zr + zi*zi > mb->bailout){
i-= FFMIN(7, i);
for(; i<mb->maxiter; i++){
zr= mb->zyklus[i][0];
zi= mb->zyklus[i][1];
if(zr*zr + zi*zi > mb->bailout){
switch(mb->outer){
case ITERATION_COUNT: zr = i; break;
case NORMALIZED_ITERATION_COUNT: zr= i + log2(log(mb->bailout) / log(zr*zr + zi*zi)); break;
}
c= lrintf((sin(zr)+1)*127) + lrintf((sin(zr/1.234)+1)*127)*256*256 + lrintf((sin(zr/100)+1)*127)*256;
break;
}
}
break;
}
}
if(!c){
if(mb->inner==PERIOD){
int j;
for(j=i-1; j; j--)
if(SQR(mb->zyklus[j][0]-zr) + SQR(mb->zyklus[j][1]-zi) < epsilon*epsilon*10)
break;
if(j){
c= i-j;
c= ((c<<5)&0xE0) + ((c<<16)&0xE000) + ((c<<27)&0xE00000);
}
}else if(mb->inner==CONVTIME){
c= floor(i*255.0/mb->maxiter+dv)*0x010101;
} else if(mb->inner==MINCOL){
int j;
double closest=9999;
int closest_index=0;
for(j=i-1; j>=0; j--)
if(SQR(mb->zyklus[j][0]) + SQR(mb->zyklus[j][1]) < closest){
closest= SQR(mb->zyklus[j][0]) + SQR(mb->zyklus[j][1]);
closest_index= j;
}
closest = sqrt(closest);
c= lrintf((mb->zyklus[closest_index][0]/closest+1)*127+dv) + lrintf((mb->zyklus[closest_index][1]/closest+1)*127+dv)*256;
}
}
c |= 0xFF000000;
color[x + y*linesize]= c;
if(next_cidx < mb->cache_allocated){
mb->next_cache[next_cidx ].p[0]= cr;
mb->next_cache[next_cidx ].p[1]= ci;
mb->next_cache[next_cidx++].val = c;
}
}
fill_from_cache(ctx, NULL, &in_cidx, &next_cidx, ci + scale/2, scale);
}
FFSWAP(void*, mb->next_cache, mb->point_cache);
mb->cache_used = next_cidx;
if(mb->cache_used == mb->cache_allocated)
av_log(0, AV_LOG_INFO, "Mandelbrot cache is too small!\n");
}
static int request_frame(AVFilterLink *link)
{
MBContext *mb = link->src->priv;
AVFilterBufferRef *picref = ff_get_video_buffer(link, AV_PERM_WRITE, mb->w, mb->h);
picref->video->sample_aspect_ratio = (AVRational) {1, 1};
picref->pts = mb->pts++;
picref->pos = -1;
ff_start_frame(link, avfilter_ref_buffer(picref, ~0));
draw_mandelbrot(link->src, (uint32_t*)picref->data[0], picref->linesize[0]/4, picref->pts);
ff_draw_slice(link, 0, mb->h, 1);
ff_end_frame(link);
avfilter_unref_buffer(picref);
return 0;
}
AVFilter avfilter_vsrc_mandelbrot = {
.name = "mandelbrot",
.description = NULL_IF_CONFIG_SMALL("Render a Mandelbrot fractal."),
.priv_size = sizeof(MBContext),
.init = init,
.uninit = uninit,
.query_formats = query_formats,
.inputs = (const AVFilterPad[]) {{ .name = NULL}},
.outputs = (const AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.request_frame = request_frame,
.config_props = config_props },
{ .name = NULL}},
};
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