[FFmpeg-devel] [PATCH 3/3] vf_colorspace: Add support for smpte 431/432 (dci/display p3) primaries

[Vittorio Giovara]

On Mon, Oct 31, 2016 at 4:08 PM, Ronald S. Bultje <rsbultje at gmail.com> wrote:
> Hi,
>
> On Mon, Oct 31, 2016 at 3:31 PM, Vittorio Giovara
> <vittorio.giovara at gmail.com> wrote:
>>
>> On Mon, Oct 31, 2016 at 2:53 PM, Ronald S. Bultje <rsbultje at gmail.com>
>> wrote:
>> > Hi,
>> >
>> > On Mon, Oct 31, 2016 at 11:13 AM, Vittorio Giovara
>> > <vittorio.giovara at gmail.com> wrote:
>> >>
>> >> On Mon, Oct 31, 2016 at 7:43 AM, Ronald S. Bultje <rsbultje at gmail.com>
>> >> wrote:
>> >> > Hi,
>> >> >
>> >> > On Mon, Oct 31, 2016 at 5:50 AM, Kevin Wheatley
>> >> > <kevin.j.wheatley at gmail.com>
>> >> > wrote:
>> >> >>
>> >> >> On Sun, Oct 30, 2016 at 1:18 PM, Ronald S. Bultje
>> >> >> <rsbultje at gmail.com>
>> >> >> wrote:
>> >> >> > Hmm... So, the wikipedia page https://en.wikipedia.org/wiki/DCI-P3
>> >> >> > refers
>> >> >> > to the two whitepoints here as DCI-P3 D65 and DCI-P3 Theater.
>> >> >> > Calling
>> >> >> > one
>> >> >> > D65 and the other DCI seems confusing in that light (assuming the
>> >> >> > wikipedia
>> >> >> > page is correct). I'd call it THEATER or DCI_P3_THEATER, to
>> >> >> > distinguish
>> >> >> > it
>> >> >> > from DCI-P3 D65. Is that OK?
>> >> >>
>> >> >> In the industry people just call it the DCI P3 white point (or
>> >> >> 'Urgh')
>> >> >> it is not limited to theater usage, you might consider it the
>> >> >> calibration white point for the reference projector, so
>> >> >> WP_DCI_P3_REFERENCE might be better, but that is a little long.
>> >> >>
>> >> >> I'd go for something like WP_DCI_P3 it is not really ambiguous.
>> >> >
>> >> >
>> >> > Hm... OK with me (though not ideal, but what do I know). Vittorio, OK
>> >> > also?
>> >> > I can modify patch so you don't have to resend.
>> >>
>> >> I find it a little long and not less confusing than my initial WP_DCI,
>> >> among all the alternatives I liked the THEATER one the most. If that's
>> >> a no-go, how about we could settle for WP_PROJ maybe?
>> >
>> >
>> > Wait, wait. Length is an issue? Really?
>> >
>> > The only reason the other names are short is because the names of the
>> > whitepoints are short. D65 is really just called that: D65. Likewise for
>> > D50. This name (whatever it is :D) is simply longer.
>>
>> It's not a matter of length but a matter of descriptiveness: right now
>> there is only one single different whitepoint defined by DCI, so IMO
>> it makes sense to call it simply WP_DCI. In case DCI adds new values,
>> naming can be modified later. The other whitepoints could also have
>> longer, more descriptive names too, like WP_ILLUMINANT_C, but at the
>> same time the WP_C shorthand is convenient and immediate (and IMO
>> better suited as variable name).
>
>
> That's actually a good point. I'm not sure if C is better than
> ILLUMINANT_C... WDYT? I guess you're sticking to the "shorter is better"? :)

In this case, yes, shorter is better, in my opinion.
-- 
Vittorio