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Old 31st July 2020, 23:06   #14  |  Link
wswartzendruber
hlg-tools Maintainer
 
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Join Date: Feb 2008
Posts: 412
Quote:
Originally Posted by Blue_MiSfit View Post
Following up on some posts from above, it sounds like the plan is to have a single 4K BT. 2020 HLG stream that will serve two groups of customers:

1) Folks with modern 4K TVs with HLG and 2020 support who will see the extended dynamic range that HLG brings in addition to the wide 2020 color gamut

2) Folks with first generation 4K TVs that are SDR, but still support 2020/WCG. They get the wider gamut, but and will still be able to watch the content acceptably even being totally naive to HLG. I imagine folks with modern 4K TVs that have HDR10 and DoVi, but still lack HLG for some reason (like my older LG B6) would fall into this category as well.

This leaves everyone else, but you'll still uplink a standard HD SDR 709 feed for them?

So... the industry is going through the hassle and compromises of HLG just to help out that small group of 4K early adopters with SDR panels that support BT. 2020? Seems a little silly to me, honestly! How big is that user-base, and how much of even the P3-D65 gamut will they even see (forget about 2020)?

There must be some other reason for using HLG. Is it just the momentum around HLG in production workflows (cameras, etc)?
If you are speaking to me, then you misunderstand. This isn't about the industry or what they want, this is about me and what I want. With that said, I am also a very big believer in open source software and in sharing work. At least a few other people will likely find this useful as well. Eventually, that is.

I want a process to rip a 4K disc such that I have a single encode that can play back on any device with a competent player. Right now, I have Alita on my desktop (Rec.709), my phone (Rec.709), and it will also be on my HTPC when I get that, which will be Rec.709 first and then Rec.2020 later on. I want a single encode for all of these devices.

And this is because I find PQ to be an absolute joke for content distribution, and a bad one at that. I am utterly convinced that the reason Dolby persuaded everyone to go along with it was because it created an artificial need for Dolby Vision, which they would in turn profit from.

My goal is to create a single workflow for PQ content that allows me to adjust and transcode anything I have into a consistent HLG stream. This means, for example, that each transcode will have a reference white level of 75% signal strength (or as best as I can manage this). VLC and Kodi already handle 2020->709 amazingly well as they are, so I don't have a colorspace issue. And I don't have a luminosity problem, either, because I've determined that VLC clips HLG at precisely the 75% mark, which is exactly what I want it to do.

Something I'm really interested in at the moment is scene-specific tone mapping via dynamic metadata, since I have to stay within 1,000 nits.

But regardless of how I get to HLG, I will never need metadata during playback. What a farce. I seriously cannot believe everyone went along with this.

EDIT: Well, I guess the BBC and NHK didn't go along with it.

Last edited by wswartzendruber; 31st July 2020 at 23:32.
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