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| author | Michael Niedermayer <michaelni@gmx.at> | 2011-11-15 21:33:11 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2011-11-15 21:33:11 +0100 |
| commit | 04bb26e3ee50a3506af924ff83bf83e13ebef9b0 (patch) | |
| tree | 1d0aeed0a1009aabaae6abe0a225a5a71547dcc8 | |
| parent | 7575980ba4ecc2e5497bdbf68ed1ee5a20ad5a5d (diff) | |
| download | ffmpeg-04bb26e3ee50a3506af924ff83bf83e13ebef9b0.tar.gz | |
mandelbrot: add dither to convergence & mincol colorings.
This avoids banding artifacts.
Note, low end TFTs still show some banding.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
| -rw-r--r-- | libavfilter/vsrc_mandelbrot.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/libavfilter/vsrc_mandelbrot.c b/libavfilter/vsrc_mandelbrot.c index f575fb1b05..194d866abe 100644 --- a/libavfilter/vsrc_mandelbrot.c +++ b/libavfilter/vsrc_mandelbrot.c @@ -72,6 +72,7 @@ typedef struct { Point *point_cache; Point *next_cache; double (*zyklus)[2]; + uint32_t dither; } MBContext; #define OFFSET(x) offsetof(MBContext, x) @@ -224,6 +225,8 @@ static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize, 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; @@ -267,7 +270,7 @@ static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize, c= ((c<<5)&0xE0) + ((c<<16)&0xE000) + ((c<<27)&0xE00000); } }else if(mb->inner==CONVTIME){ - c= (i*255/mb->maxiter)*0x010101; + c= floor(i*255.0/mb->maxiter+dv)*0x010101; } else if(mb->inner==MINCOL){ int j; double closest=9999; @@ -278,7 +281,7 @@ static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize, closest_index= j; } closest = sqrt(closest); - c= lrintf((mb->zyklus[closest_index][0]/closest+1)*127) + lrintf((mb->zyklus[closest_index][1]/closest+1)*127)*256; + c= lrintf((mb->zyklus[closest_index][0]/closest+1)*127+dv) + lrintf((mb->zyklus[closest_index][1]/closest+1)*127+dv)*256; } } c |= 0xFF000000; |