vsrc_mandelbrot.c
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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 fractal 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,
WHITE,
OUTZ,
};
enum Inner{
BLACK,
PERIOD,
CONVTIME,
MINCOL,
};
typedef struct Point {
double p[2];
uint32_t val;
} Point;
typedef struct MBContext {
const AVClass *class;
int w, h;
AVRational frame_rate;
uint64_t pts;
int maxiter;
double start_x;
double start_y;
double start_scale;
double end_scale;
double end_pts;
double bailout;
int outer;
int inner;
int cache_allocated;
int cache_used;
Point *point_cache;
Point *next_cache;
double (*zyklus)[2];
uint32_t dither;
double morphxf;
double morphyf;
double morphamp;
} 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(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, CHAR_MIN, CHAR_MAX, FLAGS },
{"r", "set frame rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.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 },
{"morphxf", "set morph x frequency", OFFSET(morphxf), AV_OPT_TYPE_DOUBLE, {.dbl=0.01}, -FLT_MAX, FLT_MAX, FLAGS },
{"morphyf", "set morph y frequency", OFFSET(morphyf), AV_OPT_TYPE_DOUBLE, {.dbl=0.0123}, -FLT_MAX, FLT_MAX, FLAGS },
{"morphamp", "set morph amplitude", OFFSET(morphamp), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -FLT_MAX, 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" },
{"white", "set white mode", 0, AV_OPT_TYPE_CONST, {.i64=WHITE}, INT_MIN, INT_MAX, FLAGS, "outer" },
{"outz", "set outz mode", 0, AV_OPT_TYPE_CONST, {.i64=OUTZ}, 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)
{
MBContext *s = ctx->priv;
s->bailout *= s->bailout;
s->start_scale /=s->h;
s->end_scale /=s->h;
s->cache_allocated = s->w * s->h * 3;
s->cache_used = 0;
s->point_cache= av_malloc_array(s->cache_allocated, sizeof(*s->point_cache));
s-> next_cache= av_malloc_array(s->cache_allocated, sizeof(*s-> next_cache));
s-> zyklus = av_malloc_array(s->maxiter + 16, sizeof(*s->zyklus));
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
MBContext *s = ctx->priv;
av_freep(&s->point_cache);
av_freep(&s-> next_cache);
av_freep(&s->zyklus);
}
static int query_formats(AVFilterContext *ctx)
{
static const enum AVPixelFormat pix_fmts[] = {
AV_PIX_FMT_0BGR32,
AV_PIX_FMT_NONE
};
AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
if (!fmts_list)
return AVERROR(ENOMEM);
return ff_set_common_formats(ctx, fmts_list);
}
static int config_props(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->src;
MBContext *s = ctx->priv;
if (av_image_check_size(s->w, s->h, 0, ctx) < 0)
return AVERROR(EINVAL);
inlink->w = s->w;
inlink->h = s->h;
inlink->time_base = av_inv_q(s->frame_rate);
return 0;
}
static void fill_from_cache(AVFilterContext *ctx, uint32_t *color, int *in_cidx, int *out_cidx, double py, double scale){
MBContext *s = ctx->priv;
if(s->morphamp)
return;
for(; *in_cidx < s->cache_used; (*in_cidx)++){
Point *p= &s->point_cache[*in_cidx];
int x;
if(p->p[1] > py)
break;
x= lrint((p->p[0] - s->start_x) / scale + s->w/2);
if(x<0 || x >= s->w)
continue;
if(color) color[x] = p->val;
if(out_cidx && *out_cidx < s->cache_allocated)
s->next_cache[(*out_cidx)++]= *p;
}
}
static int interpol(MBContext *s, 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==s->w || y+1==s->h)
return 0;
dist= FFMAX(FFABS(x-(s->w>>1))*s->h, FFABS(y-(s->h>>1))*s->w);
if(dist<(s->w*s->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 *s = ctx->priv;
int x,y,i, in_cidx=0, next_cidx=0, tmp_cidx;
double scale= s->start_scale*pow(s->end_scale/s->start_scale, pts/s->end_pts);
int use_zyklus=0;
fill_from_cache(ctx, NULL, &in_cidx, NULL, s->start_y+scale*(-s->h/2-0.5), scale);
tmp_cidx= in_cidx;
memset(color, 0, sizeof(*color)*s->w);
for(y=0; y<s->h; y++){
int y1= y+1;
const double ci=s->start_y+scale*(y-s->h/2);
fill_from_cache(ctx, NULL, &in_cidx, &next_cidx, ci, scale);
if(y1<s->h){
memset(color+linesize*y1, 0, sizeof(*color)*s->w);
fill_from_cache(ctx, color+linesize*y1, &tmp_cidx, NULL, ci + 3*scale/2, scale);
}
for(x=0; x<s->w; x++){
float av_uninit(epsilon);
const double cr=s->start_x+scale*(x-s->w/2);
double zr=cr;
double zi=ci;
uint32_t c=0;
double dv= s->dither / (double)(1LL<<32);
s->dither= s->dither*1664525+1013904223;
if(color[x + y*linesize] & 0xFF000000)
continue;
if(!s->morphamp){
if(interpol(s, color, x, y, linesize)){
if(next_cidx < s->cache_allocated){
s->next_cache[next_cidx ].p[0]= cr;
s->next_cache[next_cidx ].p[1]= ci;
s->next_cache[next_cidx++].val = color[x + y*linesize];
}
continue;
}
}else{
zr += cos(pts * s->morphxf) * s->morphamp;
zi += sin(pts * s->morphyf) * s->morphamp;
}
use_zyklus= (x==0 || s->inner!=BLACK ||color[x-1 + y*linesize] == 0xFF000000);
if(use_zyklus)
epsilon= scale*(abs(x-s->w/2) + abs(y-s->h/2))/s->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(s->zyklus[i>>1][0]-outr)+fabs(s->zyklus[i>>1][1]-outi) <= epsilon)\
break;\
}\
s->zyklus[i][0]= outr;\
s->zyklus[i][1]= outi;\
for(i=0; i<s->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 > s->bailout){
i-= FFMIN(7, i);
for(; i<s->maxiter; i++){
zr= s->zyklus[i][0];
zi= s->zyklus[i][1];
if(zr*zr + zi*zi > s->bailout){
switch(s->outer){
case ITERATION_COUNT:
zr = i;
c = lrintf((sinf(zr)+1)*127) + lrintf((sinf(zr/1.234)+1)*127)*256*256 + lrintf((sinf(zr/100)+1)*127)*256;
break;
case NORMALIZED_ITERATION_COUNT:
zr = i + log2(log(s->bailout) / log(zr*zr + zi*zi));
c = lrintf((sinf(zr)+1)*127) + lrintf((sinf(zr/1.234)+1)*127)*256*256 + lrintf((sinf(zr/100)+1)*127)*256;
break;
case WHITE:
c = 0xFFFFFF;
break;
case OUTZ:
zr /= s->bailout;
zi /= s->bailout;
c = (((int)(zr*128+128))&0xFF)*256 + (((int)(zi*128+128))&0xFF);
}
break;
}
}
break;
}
}
if(!c){
if(s->inner==PERIOD){
int j;
for(j=i-1; j; j--)
if(SQR(s->zyklus[j][0]-zr) + SQR(s->zyklus[j][1]-zi) < epsilon*epsilon*10)
break;
if(j){
c= i-j;
c= ((c<<5)&0xE0) + ((c<<10)&0xE000) + ((c<<15)&0xE00000);
}
}else if(s->inner==CONVTIME){
c= floor(i*255.0/s->maxiter+dv)*0x010101;
} else if(s->inner==MINCOL){
int j;
double closest=9999;
int closest_index=0;
for(j=i-1; j>=0; j--)
if(SQR(s->zyklus[j][0]) + SQR(s->zyklus[j][1]) < closest){
closest= SQR(s->zyklus[j][0]) + SQR(s->zyklus[j][1]);
closest_index= j;
}
closest = sqrt(closest);
c= lrintf((s->zyklus[closest_index][0]/closest+1)*127+dv) + lrintf((s->zyklus[closest_index][1]/closest+1)*127+dv)*256;
}
}
c |= 0xFF000000;
color[x + y*linesize]= c;
if(next_cidx < s->cache_allocated){
s->next_cache[next_cidx ].p[0]= cr;
s->next_cache[next_cidx ].p[1]= ci;
s->next_cache[next_cidx++].val = c;
}
}
fill_from_cache(ctx, NULL, &in_cidx, &next_cidx, ci + scale/2, scale);
}
FFSWAP(void*, s->next_cache, s->point_cache);
s->cache_used = next_cidx;
if(s->cache_used == s->cache_allocated)
av_log(ctx, AV_LOG_INFO, "Mandelbrot cache is too small!\n");
}
static int request_frame(AVFilterLink *link)
{
MBContext *s = link->src->priv;
AVFrame *picref = ff_get_video_buffer(link, s->w, s->h);
if (!picref)
return AVERROR(ENOMEM);
picref->sample_aspect_ratio = (AVRational) {1, 1};
picref->pts = s->pts++;
draw_mandelbrot(link->src, (uint32_t*)picref->data[0], picref->linesize[0]/4, picref->pts);
return ff_filter_frame(link, picref);
}
static const AVFilterPad mandelbrot_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.request_frame = request_frame,
.config_props = config_props,
},
{ NULL }
};
AVFilter ff_vsrc_mandelbrot = {
.name = "mandelbrot",
.description = NULL_IF_CONFIG_SMALL("Render a Mandelbrot fractal."),
.priv_size = sizeof(MBContext),
.priv_class = &mandelbrot_class,
.init = init,
.uninit = uninit,
.query_formats = query_formats,
.inputs = NULL,
.outputs = mandelbrot_outputs,
};