Re: [EXTERNAL] Re: Conformance files in PQ, HLG, SDR-BT.709?

Sorry I was in a rush to get to another meeting, meant to add the link, 
forgot

The page is here:
https://www.nayuki.io/page/png-file-chunk-inspector

source is here:
https://github.com/nayuki/Nayuki-web-published-code/tree/master/png-file-chunk-inspector

my unofficial extension to that code to add cICP support is very simple

["cICP", "Coding-independent code points ", false, (chunk, earlier) =>{
addErrorIfHasType(earlier, "PLTE", chunk, "Chunk must be before PLTE 
chunk");
addErrorIfHasType(earlier, "IDAT", chunk, "Chunk must be before IDAT 
chunk");
if(chunk.data.length !=4) {
chunk.errorNotes.push("Invalid data length");
return;
             }
constchromaticities=chunk.data[0];
consttransfer=chunk.data[1];
constmatrix=chunk.data[2];
constvideowidth=chunk.data[3];
if(matrix!==0) {
chunk.errorNotes.push("PNG only supports RGB data");
             }
if(videowidth>1) {
chunk.errorNotes.push("Undefined video width value, must be narrow or 
full");
             }
// look for specific, common combination values first
if(chromaticities===1) {
// HDTV or sRGB
if(transfer===1) {
chunk.innerNotes.push(`Rec BT.709 HDTV`);
                 } elseif(transfer===8) {
chunk.innerNotes.push(`Linear-light sRGB`);
                 } elseif(transfer===13) {
chunk.innerNotes.push(`IEC 61966-2-1 sRGB`);
                 }
             } elseif(chromaticities===9) {
// BT.2020 or BT.2100
if(transfer===14) {
chunk.innerNotes.push(`Rec. ITU-R BT.2020-2 (10-bit system)`);
                 } elseif(transfer===15) {
chunk.innerNotes.push(`Rec. ITU-R BT.2020-2 (12-bit system)`);
                 } elseif(transfer===16) {
chunk.innerNotes.push(`Rec. ITU-R BT.2100-2 (PQ system)`);
                 } elseif(transfer===18) {
chunk.innerNotes.push(`Rec. ITU-R BT.2100-2 (HLG system)`);
                 };
// Only mention narrow or full range if both are actually options
if(videowidth===0) {
chunk.innerNotes.push(`Narrow Range`);
                 } else{
chunk.innerNotes.push(`Full Range`);
                 };
             } elseif(chromaticities===12) {
// SMPTE EG 432-1 (2010) - DCI D65
if(transfer===13) {
// Display-P3 uses sRGB transfer function
chunk.innerNotes.push(`Display-P3`);
                 }
             }
else{
// Not common combination
letc, t, m, p;
c=chromaticities.toString();
chunk.innerNotes.push(`Chromaticity: ${c}`);
t=transfer.toString();
chunk.innerNotes.push(`Transfer: ${t}`);
m=(matrix===0) ?"RGB":"YCC";
chunk.innerNotes.push(`Matrix: ${m}`);
p=(videowidth===0) ?"Narrow":"Wide";
chunk.innerNotes.push(`videowidth: ${p}`);
             }
         }],

On 2023-12-08 14:08, Seeger, Chris (NBCUniversal) wrote:
>
> Do you have a link to it 😊
>
> Also, did I mention that MediaInfo now has support in their nightly 
> build (I’ve been sending out too many emails this morning).
>
> https://mediaarea.net/download/snapshots/binary/mediainfo-gui/
>
> -Chris
>
> *From: *Chris Lilley <chris@w3.org>
> *Date: *Friday, December 8, 2023 at 1:53 PM
> *To: *public-png@w3.org <public-png@w3.org>
> *Subject: *Re: [EXTERNAL] Re: Conformance files in PQ, HLG, SDR-BT.709?
>
> There is a nice PNG file chunk inspector, all written in JavaScript
>
> I took a copy and extended it to support cICP. Here is a screenshot of 
> the output. I recognize the most common color spaces and output their 
> names, otherwise I output the actual data.
>
> -- 
> Chris Lilley
> @svgeesus
> Technical Director @ W3C
> W3C Strategy Team, Core Web Design
> W3C Architecture & Technology Team, Core Web & Media

-- 
Chris Lilley
@svgeesus
Technical Director @ W3C
W3C Strategy Team, Core Web Design
W3C Architecture & Technology Team, Core Web & Media