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

[Ronald S. Bultje]

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"? :)

Ronald