HDR Discussion Thread

[PaulGo]

Originally Posted by Geoff D

HDR10 DOES change on a scene by scene basis which is probably the single biggest misconception about HDR, the content itself is graded scene by scene and is not locked to a constant 1000/4000 nits no more than regular SDR content is 'locked' to a constant 120 nits. It's just a container which can go as dark or as bright or as colourful or as desaturated as the colourist desires in any given shot.

The problem is that the interpretation of the image by the target display is 'static'. This is not an issue for something that can resolve 1000/4000 nits and 100% of P3 because it has no need of mapping the image, you will see it as the colourist intended. But when it comes to mapping that material into something that has less brightness and less colour volume THEN the inherent problems with static metadata rear their head because the display has no idea about how best to maximise the image from shot to shot to best fit the parameters of the display, it can only offer a 'best guess' which varies from manufacturer to manufacturer.

[edit] Indeed, this is where DV's dynamic system is unique because it doesn't just derive dynamic metadata from the master, it also specifies that a 'golden reference' for each display type be programmed in so that x display actually knows how best to leverage the metadata against its specific capabilities. A map is less useful without a compass, you know? This is also why DV on projectors ain't happening any time soon, because they cannot isolate a particular 'golden reference' owing to the projection screen's qualities being almost as important as the projektor itself, and the two are rarely bundled together in any official capacity.

If HDR10 does change on a scene by scene basis how does this differ from HDR10+?

[Geoff D]

Originally Posted by PaulGo

If HDR10 does change on a scene by scene basis how does this differ from HDR10+?

The image as encoded to the PQ EOTF in HDR10 does indeed change but not the metadata that goes with it, which is what's so crucial in informing the target display of how best to downconvert the PQ signal to fit its own parameters. This is because of the usage of absolute luminance rather than relative, the performance of the display is pre-assumed in an absolute system but is part of the actual final rendering of the image in a metadata-less relative system like HLG.

If your display doesn't meet that pre-assumption then the image will need to be downconverted to fit and static metadata doesn't cover this on a scene-by-scene basis, it simply gives the min/max mastering levels plus a fixed maximum peak content light level and maximum frame average light level i.e. the highest point of the presentation for each value. And some discs don't even have those.

This is why dynamic metadata is quite frankly a necessity that's long overdue in the PQ-based HDR world, as when interpreted by the target display it can be thusly informed on how best it can adjust the images on a scene-by-scene (or even frame-by-frame in the case of DV) basis. The grading at its core does not change, only the application & deployment of the metadata which is precisely how they'll be able to generate HDR10+ metadata from existing grades: that "dynamic" information is literally gleaned from spectral analysis of the HDR10 grade.

[PeterTHX]

Originally Posted by BrownianMotion

Samsung lying in their promotional and technical papers about HDR10+. Not sure how much of a difference scene-by-scene vs frame-by-frame makes in practice, but it's very interesting that they would lie about it.

Well they overplayed the "free" aspect when they indeed charge a yearly membership fee.

They also didn't mention the automated HDR10+ servers are powered by recalled Note 7 batteries.

[BrownianMotion]

Given the issues with Dolby Vision over HDMI that have been discussed recently, I thought it would only be fair to address issues with the other dynamic HDR format over HDMI.

Here is how Samsung was able to make HDR10+ work over HDMI 2.0:

So how is this possible without HDMI 2.1’s ‘Dynamic HDR’ feature? FlatpanelsHD reported in September 2017 that HDR10+ works over HDMI 2.0b. At CES 2018, Samsung confirmed this information and explained that it is using a solution called ‘Infoframe’. It can carry 24Kb of metadata in the signal, which can then be interpreted by the display.

However, there are some issues that need to be ironed out:

Samsung demonstrated this HDR10+ approach at CES 2018 during a private session with an UHD Blu-ray player running beta software. FlatpanelsHD noticed that whenever a scene changed, a short blink in the picture would occur, which negatively affected the viewing experience. We were not allowed to shoot video or take photos during the session.

We brought up the issue with Samsung’s engineers who explained that it was caused by a small lag between when the scene changed and when the dynamic metadata kicked in, meaning that the next scene would briefly adhere to the previous scene’s metadata. Samsung further said that it is working on a fix for the problem and that the certification process for HDR10+ will include testing for the issue.

https://www.flatpanelshd.com/news.ph...&id=1516011308

Dynamic HDR in general is a big headache right now, it seems.

[gkolb]

Originally Posted by BrownianMotion

Given the issues with Dolby Vision over HDMI that have been discussed recently, I thought it would only be fair to address issues with the other dynamic HDR format over HDMI.
...

https://www.flatpanelshd.com/news.ph...&id=1516011308

Dynamic HDR in general is a big headache right now, it seems.

Scotty, this is the Captain, increase warp drive to maximum to handle the dynamic metadata overloading...

[Penton-Man]

Originally Posted by PeterTHX

free

In case you’re interested as I know you like your audio, the event will sell out -
https://www.eventbrite.com/e/the-sou...ts-42157463107

[Penton-Man]

Originally Posted by PaulGo

I prefer 3D movies

3D aficionados shouldn’t give up hope entirely on 3D. There are valleys and peaks with the format like realized with the last resurgence. On 'the keeping alive 3D front', there may be at least a little display news out of the show in Amsterdam next month - https://www.iseurope.org/ .

As an aside, one potential application for 8K (https://forum.blu-ray.com/showthread.php?t=296952 ) TV which I do like is that it’s a good pathway for 3D because it can serve as a very convenient method for producing 3D in 4K.

[Penton-Man]

Originally Posted by Penton-Man

In case you’re interested as I know you like your audio, the event will sell out -
https://www.eventbrite.com/e/the-sou...ts-42157463107

Also, ICYMI, PKD’s ED is set to be released in HDR by Amazon.

[Penton-Man]

Originally Posted by Penton-Man

https://www.eventbrite.com/e/the-sou...ts-42157463107

Grow, or lose one’s independence….http://variety.com/2018/biz/news/son...pe-1202666886/

[Penton-Man]

https://forum.blu-ray.com/showthread...e#post14593633

^ Note to Robert Z. (Geoff, I don’t know if you’re married, so it may not apply), but as to my redemption.
I’m back into marital bliss and out of the doghouse by promising to do my household chores on time and showing her a reservation I just made for us for a really nice suite in the Westin Bayshore tower in the city she really likes to take summer holiday….

[Geoff D]

I'm not married or otherwise domestically intertwined, why do you think I spend so much time on here?

[Penton-Man]

Originally Posted by Geoff D

I'm not married or otherwise domestically intertwined, why do you think I spend so much time on here?

? To gain nuanced tidbits of new wisdom from those in the know for example, that cats and dogs can happily work together on some aspects of HDR completely unknown to hobbyist forums:




Anyway, for me, whether I were domestically intertwined or not, I’m compelled to reset from time to time by getting away from all devices with a screen. I clear my mind by going off-road, be it in state or national parks, or the woods on 2-wheels. Not competing this year, but at least spectating….
https://www.bcbikerace.com/the-journ...rth-vancouver/

https://vimeo.com/223353871

and then riding the Shore once the participants move on to the next stage.

[Staying Salty]

So this had to be in the works since 2017 CES. No way that Sony announced DoVi support without this understanding with Dolby. I guess we can cut LG some slack on their 970 player. I would imagine that Oppo had a heads up. Am I assuming correctly that current DoVi displays will be able to process this new HDMI signal with a FW update? If it requires less horse power on the displays part, then I would think it could be implemented into less expensive displays.

Will be another interesting year.

[LordoftheRings]

Originally Posted by Staying Salty

Will be another interesting year.

You betcha. 2018 is going to be the prelude to 2019...8K with 3D glasses-free.

[LordoftheRings]

Bonus...vision:

https://www.youtube.com/watch?v=JMsJ...ature=youtu.be

[Staying Salty]

I believe this has been in the works for over a year. My time line:

1. 2016: Sony works out an agreement with Dolby to support Dolby Vision if they can use "low latency" HDMI. Dolby needs Sony on board to counter Samsung’s HDR10+. Also this method in the long run will provide a better DoVi ecosystem.

2. 2016: Dolby informs Oppo but Oppo cannot change to this and still meet DoVi playback by the first DoVi disc release. Will be able to update later (2018).

3. 2017: Sony announces DoVi support at CES.

4. 2017: LG is informed at some point and pulls is DoVi player update.

5. 2017: The Dolby Vision family begins working on "low latency" HDMI.

6. 2018: It all comes together.

As of today only three players have the DoVi capability. They are all based on the Oppo foundation.

All the current DoVi displays will be FW updated to the new "low latency" HDMI. If this is not true, then all HE double L is going to break lose.

I cannot see Dolby accepting Sony’s solution and totally cutting off the current equipment owners. Again all HE double L will break lose if this happens.

[Corpboy]

What is DoVi?

[Staying Salty]

Originally Posted by Corpboy

What is DoVi?

Originally Posted by Penton-Man

You liked that particular acronym.
Rather than DV, it’s actually been quite popular for months among the compressionists in professional groups like on linkedin. I feared if I were to use it before, instead of the easily understood/common ‘DV’, it would confuse folks on hobbyist forums.

Every one wants to hang with the Penton-Man

[LordoftheRings]

DV ... Dolby Vision ...DoVi ... True dat

And, the Panasonic 820 and Sony 700 won't be Dolby Vision till sometimes this Summer.
So, right now and for roughly six months only the Opoo 203/205 are doing Dolby Vision from 4K discs...and?

[Staying Salty]

Latency = lag, the bane of gamers

It is right there in front of us guys and gals.

1. Why would Dolby risk upsetting it’s partners by creating a "low latency" DoVi for Sony. Yes it’s nice to get their “Name” and the royalties for their displays and 4k Blu-ray players. But is it worth the risk for the hardship (money to update their equipment) this will impose on their partners? Also the anger and bad press they will initially get. I don’t think so. But what if those players are sold in the millions and millions. You say it would take many, many, many years for Sony to sell that many players. But what if we change to name from 4k standalone player, to Dolby Vision supported gaming console. Bingo, you bet.

2. Now this does not benefit Oppo or any other 4k standalone player maker at first glance. But most of the other player makers also make displays. They would not want to cede the display market to Sony when the gamers choose a display to match with their brand new console. So it is not too difficult for them to buy into the new DoVi standard.

3. With this support the game developers will make DoVi games for these consoles. Win (money) for Dolby.

4. Oppo and the streaming dudes will not want to cede Sony display support to other manufactures so they will benefit also.

We that’s my story and I am sticking to it. At least until tomorrow.