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

[Hendrik Leppkes]

On Wed, Oct 14, 2015 at 12:37 PM, Ganesh Ajjanagadde <gajjanag at mit.edu> wrote:
> On Wed, Oct 14, 2015 at 5:01 AM, Matt Oliver <protogonoi at gmail.com> wrote:
>> On 14 October 2015 at 09:46, Ganesh Ajjanagadde <gajjanag at mit.edu> wrote:
>>
>>> On Tue, Oct 13, 2015 at 9:12 AM, Ganesh Ajjanagadde <gajjanag at mit.edu>
>>> wrote:
>>> > On Tue, Oct 13, 2015 at 4:02 AM, Clément Bœsch <u at pkh.me> wrote:
>>> >> On Tue, Oct 13, 2015 at 09:25:03AM +0200, Paul B Mahol wrote:
>>> >> [...]
>>> >>> What about fmax/FFMAX?
>>> >>
>>> >> Feel free to try that out (it looks OT regarding the patch), but fmax()
>>> >> looks glibc specific
>>>
>>> Seems they are actually ISO:
>>> http://en.cppreference.com/w/c/numeric/math/fmax
>>>
>>> Can someone check availability on all of our platforms of interest
>>> (e.g Microsoft)?
>>>
>>
>> fmax and fmin are only available on msvc using 2013 or newer. Currently the
>> only msvc version without fmax/fmin that FFmpeg supports is 2012 which uses
>> the C99 to C89 converter.
>
> And does that converter handle fmin, fmax, fmaxf, etc?
> Does it need patches?
> Bottom line: are they safe to use at the moment?
>

No, they are not.

One thing I don't understand - why are we bothering with something
that at best comes out as "same speed" from tests performed? (low
number of runs are irrelevant as they are not statistically
significant).