[FFmpeg-devel] [PATCH] avfilter, swresample, swscale: use fabs, fabsf instead of FFABS

Hendrik Leppkes h.leppkes at gmail.com
Wed Oct 14 13:02:08 CEST 2015


On Wed, Oct 14, 2015 at 12:57 PM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
> Hendrik Leppkes <h.leppkes <at> gmail.com> writes:
>
>> > If you could show that it is faster on any platform
>> > I would already be happy!
>> >
>>
>> A more important check would be that its not significantly
>> slower on any other platform. Just because one
>> compiler/glibc combination manages to produce an efficient
>> inlined function doesn't necessarily mean that some other
>> compiler or libc couldn't produce a full function call
>> with all the overhead that comes with it, becoming
>> significantly slower.
>
> I thought we all agree that such a platform exists
> somewhere (sometimes) but that a performance gain
> on x86 Linux is more important, no?
>

But for that to be true there must be a clear gain - which this change
has yet to proof. Testing a significant amount of runs seems to come
out at about same speed from all the numbers the author himself
posted.

- Hendrik


More information about the ffmpeg-devel mailing list