On Wed, Mar 16, 2016 at 7:14 PM, Michael Niedermayer <mich...@niedermayer.cc> wrote: > On Mon, Mar 14, 2016 at 10:04:59PM -0400, Ganesh Ajjanagadde wrote: >> This is ~2x faster for y not an integer on Haswell+GCC, and should >> generally be faster due to the fact that anyway powf essentially does >> this under the hood. Made an inline function in lavu/internal.h for this >> purpose. >> >> Note that there are some accuracy differences, that should generally be >> negligible. In particular, FATE still passes on this platform. >> >> Results in ~ 7% speedup in aac encoding with -march=native, Haswell+GCC. >> before: >> ffmpeg -i sin.flac -acodec aac -y sin_new.aac 6.05s user 0.06s system 104% >> cpu 5.821 total >> >> after: >> ffmpeg -i sin.flac -acodec aac -y sin_new.aac 5.67s user 0.03s system 105% >> cpu 5.416 total >> >> This is also faster than an alternative approach that pulls in powf, gets >> rid of >> the crufty NaN checks and other special cases, exploits knowledge about the >> intervals, etc. >> This of course does not exclude smarter approaches; just suggests that >> there would need to be significant work on this front of lower utility than >> searches for hotspots elsewhere. >> >> Reviewed-by: Reimar Döffinger <reimar.doeffin...@gmx.de> >> Reviewed-by: Ronald S. Bultje <rsbul...@gmail.com> >> Signed-off-by: Ganesh Ajjanagadde <gajja...@gmail.com> >> --- >> libavcodec/aacenc_utils.h | 6 +++++- >> libavutil/internal.h | 16 ++++++++++++++++ >> 2 files changed, 21 insertions(+), 1 deletion(-) > > Tested on mingw-wine, linux x86_64 & x86_32 and mips qemu
pushed, thanks > > [...] > -- > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB > > The real ebay dictionary, page 1 > "Used only once" - "Some unspecified defect prevented a second use" > "In good condition" - "Can be repaird by experienced expert" > "As is" - "You wouldnt want it even if you were payed for it, if you knew ..." > > _______________________________________________ > 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
