ffmpeg | branch: master | Ganesh Ajjanagadde <gajjanaga...@gmail.com> | Tue Nov 24 13:00:54 2015 -0500| [990619968a40ff64f789ba7d004a118351695fa6] | committer: Ganesh Ajjanagadde
avfilter/vsrc_mandelbrot: change sin to sinf for color computation lrintf is anyway used, suggesting we only care up to floating precision. Rurthermore, there is a compat hack in avutil/libm for this function, and it is used in avcodec/aacps_tablegen.h. This yields a non-negligible speedup. Sample benchmark: x86-64, Haswell, GNU/Linux: old (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 new (draw_mandelbrot): 269882717 decicycles in draw_mandelbrot, 256 runs, 0 skips 296359285 decicycles in draw_mandelbrot, 512 runs, 0 skips 370076599 decicycles in draw_mandelbrot, 1024 runs, 0 skips 331478354 decicycles in draw_mandelbrot, 2048 runs, 0 skips 571904318 decicycles in draw_mandelbrot, 4096 runs, 0 skips Reviewed-by: Michael Niedermayer <mich...@niedermayer.cc> Signed-off-by: Ganesh Ajjanagadde <gajjanaga...@gmail.com> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=990619968a40ff64f789ba7d004a118351695fa6 --- libavfilter/vsrc_mandelbrot.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavfilter/vsrc_mandelbrot.c b/libavfilter/vsrc_mandelbrot.c index 91bf63f..063b7d1 100644 --- a/libavfilter/vsrc_mandelbrot.c +++ b/libavfilter/vsrc_mandelbrot.c @@ -334,11 +334,11 @@ static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize, switch(s->outer){ case ITERATION_COUNT: zr = i; - c = lrintf((sin(zr)+1)*127) + lrintf((sin(zr/1.234)+1)*127)*256*256 + lrintf((sin(zr/100)+1)*127)*256; + 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((sin(zr)+1)*127) + lrintf((sin(zr/1.234)+1)*127)*256*256 + lrintf((sin(zr/100)+1)*127)*256; + 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; _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
