On 07.03.2016, at 04:04, Ganesh Ajjanagadde <gajja...@gmail.com> wrote: > On Sun, Mar 6, 2016 at 1:43 PM, Reimar Döffinger > <reimar.doeffin...@gmx.de> wrote: >> On Sun, Mar 06, 2016 at 07:35:58PM +0100, Reimar Döffinger wrote: >>> Approximately 10% faster transcode from mp3 to aac >>> with default settings. >> >> Note to anyone wanting to optimize it further: >> There is almost 25% on the table if you can replace >> the pow() and cos() function uses by something more >> efficient. > > So I did try one thing, namely in lavc/aacenc_utils, replace powf in > find_form_factor by a conditional checking for 2.0f, squaring if it > is, powf otherwise (see lavc/aaccoder_twoloop for the calls, one is > with 2.0f, other without), but it yields essentially nothing. > > Likewise, an even more trivial one is line 125 of aaccoder_twoloop: > powf can be replaced here by sqrtf(sqrtf()), but this also yields > nothing.
Probably those cases are already optimized by the implementation. > Can you be more specific, and are you sure about this? Just run your favourite performance analysis tool and you'll see. As it is non-inlined libc code I'm fairly sure the numbers are accurate enough. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
