Re: [EXTERNAL] Re: clli change from mLUm

Hi,

I’ve made the changes and added a note about zero values (means unknown).  I didn’t see any references to what to do if a value is absent (can you point me in the right direction?).  I also made a note related to algorithmic filtering to generate the MaxCLL value (to avoid false values from noise, processing, compression).

From: Pierre-Anthony Lemieux <pal@sandflow.com>
Date: Tuesday, March 21, 2023 at 7:04 PM
To: Chris Blume (ProgramMax) <programmax@gmail.com>
Cc: Seeger, Chris (NBCUniversal) <Chris.Seeger@nbcuni.com>, public-png@w3.org <public-png@w3.org>
Subject: Re: [EXTERNAL] Re: clli change from mLUm
Ok. We should use the opportunity to make the semantics consistent
with these other spec. See my comment in the ticket.

On Tue, Mar 21, 2023 at 3:27 PM Chris Blume (ProgramMax)
<programmax@gmail.com> wrote:
>
> A.) Necessary? No. But I think it is a good move.
> We could have named the chunk "aBCd". That would have been a bad name though.
> We came up with "mLUm" out of nowhere. When read as "max luminance", it is somewhat descriptive.
> But since there is already an industry standard around "CLLI", I feel like that is a much better name than our pulled-from-thin-air name.
>
> B.) I believe we originally designed the chunk to match existing other specs, byte for byte.
>
> I created a GitHub issue and assigned it to you, Chris Seeger.
> I vote that we go ahead with the rename. It sounds like Chris Lilley feels similarly.
>
> On Tue, Mar 21, 2023 at 6:10 PM Seeger, Chris (NBCUniversal) <Chris.Seeger@nbcuni.com> wrote:
>>
>> Everything is the same except the name.
>>
>>
>>
>> It’s a change from mLUm to cLLi everywhere in the doc.
>>
>>
>>
>> Data and syntax are unchanged.
>>
>>
>>
>> cLLi will match the full descriptive name “Content Light Level Information” which is used everywhere else.  It was a miss on my part, but I think will avoid confusion for those who are familiar with pre-existing terminology: cLLi.
>>
>>
>>
>> -Chris
>>
>>
>>
>>
>>
>> From: Pierre-Anthony Lemieux <pal@sandflow.com>
>> Date: Tuesday, March 21, 2023 at 5:56 PM
>> To: Seeger, Chris (NBCUniversal) <Chris.Seeger@nbcuni.com>
>> Cc: Chris Blume (ProgramMax) <programmax@gmail.com>, public-png@w3.org <public-png@w3.org>
>> Subject: [EXTERNAL] Re: clli change from mLUm
>>
>> (a) Is this absolutely necessary and (b) are the semantics and
>> encoding of the ISO structure identical to the current mLUm?
>>
>> On Tue, Mar 21, 2023 at 2:53 PM Seeger, Chris (NBCUniversal)
>> <Chris.Seeger@nbcuni.com> wrote:
>> >
>> > Hi Everyone,
>> >
>> >
>> >
>> > Should I proceed with the cLLi change from mLUm?
>> >
>> >
>> > Best,
>> > Chris