On Tue, Nov 24, 2015 at 2:28 PM, Michael Niedermayer <michae...@gmx.at> wrote: > On Tue, Nov 24, 2015 at 12:02:24PM -0500, Ganesh Ajjanagadde wrote: >> This rewrites into a similar expression avoiding sqrt. Similarity is >> assured since sqrt(x^2 + y^2)/(x+y) lies in [1/sqrt(2), 1] for x, y > 0. >> >> Tested on x86-64, Haswell, GNU/Linux. >> Command: >> ffmpeg -f lavfi -i mandelbrot -f null - >> >> old (draw_mandelbrot): >> 277625266 decicycles in draw_mandelbrot, 256 runs, 0 skips >> 304527322 decicycles in draw_mandelbrot, 512 runs, 0 skips >> 377593582 decicycles in draw_mandelbrot, 1024 runs, 0 skips >> 338539499 decicycles in draw_mandelbrot, 2048 runs, 0 skips >> 583630357 decicycles in draw_mandelbrot, 4096 runs, 0 skips >> >> new (draw_mandelbrot): >> 274635709 decicycles in draw_mandelbrot, 256 runs, 0 skips >> 300287046 decicycles in draw_mandelbrot, 512 runs, 0 skips >> 371819935 decicycles in draw_mandelbrot, 1024 runs, 0 skips >> 336663765 decicycles in draw_mandelbrot, 2048 runs, 0 skips >> 581851016 decicycles in draw_mandelbrot, 4096 runs, 0 skips >> >> Reviewed-by: Michael Niedermayer <mich...@niedermayer.cc> >> Signed-off-by: Ganesh Ajjanagadde <gajjanaga...@gmail.com> >> --- >> libavfilter/vsrc_mandelbrot.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) > > LGTM > > thx
pushed, thanks. > > [...] > -- > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB > > Rewriting code that is poorly written but fully understood is good. > Rewriting code that one doesnt understand is a sign that one is less smart > then the original author, trying to rewrite it will not make it better. > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
