[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 5:51 PM, Vittorio Giovara <
vittorio.giovara at gmail.com> wrote:

> 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.


OK fine then we'll keep it as-is.

Happy halloween!
Ronald