generic-library/ffmpeg
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

vsrc_mandelbrot: spatial interpolation

Browse Source 
speeds the code up by a factor of about 2-3.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2011-11-19 19:41:28 +01:00
parent 56fc4cf04f
commit ca14808275
1 changed files with 68 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

72
libavfilter/vsrc_mandelbrot.c
View File

@ -206,6 +206,58 @@ static void fill_from_cache(AVFilterContext *ctx, uint32_t *color, int *in_cidx,
}
}
static int interpol(MBContext *mb, uint32_t *color, int x, int y, int linesize)
{
uint32_t a,b,c,d, i;
uint32_t ipol=0;
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;
ipol |= ((ipolab + ipolcd + 2)/4)<<s;
}
color[x + y*linesize]= ipol | 0xFF000000;
return 1;
}
static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize, int64_t pts)
{
MBContext *mb = ctx->priv;
@ -213,12 +265,16 @@ static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize,
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);
memset(color+linesize*y, 0, sizeof(*color)*mb->w);
fill_from_cache(ctx, color+linesize*y, &in_cidx, &next_cidx, ci, scale);
tmp_cidx= in_cidx;
fill_from_cache(ctx, color+linesize*y, &tmp_cidx, NULL, ci + scale/2, scale);
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++){
const double cr=mb->start_x+scale*(x-mb->w/2);
@ -230,6 +286,14 @@ static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize,
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);