HDR Discussion Thread

[alexanderg823]

Originally Posted by DisplayCalNoob

BD100 with its bit rate and storage capacity, should be the defacto , UHD BluRay HDR/DV spec. So why isn't it?

Less image compression, better image information detail, and better HDR detail.

Does BD100 offer a bitrate advantage in terms of bandwidth over BD66?

Is that much space necessary for movies under 2 hours?

[puddy77]

An opinion piece from the President's Desk in the August 2018 American Cinematographer:

The Blind Awakening

High dynamic range, or HDR, is among the latest and certainly one of the most game-changing technologies to impact our work as cinematographers. Presented as the next best thing — with increased contrast, extended range and the ability to handle a wide gamut of colors — it’s a huge step in image presentation. But is it a step forward or back?

I’ll save you a detailed technical analysis, for which there are many articles written by knowledgeable technicians. Instead, what has been on my mind is how this technology changes the way we might shoot and finish our images — provided, of course, we’re even in a position to finish our images, which unfortunately is not always the case. Many previously released movies and television shows are being retransferred in HDR, and in many of those cases the cinematographers have not been invited to participate. Even on new projects, the cinematographer is not always invited for the coloring, whether or not it involves HDR.

HDR is prized for its extended range and ability to see incredible definition in the highlights. Those selling HDR always demonstrate the vivid crimson skies of sunset, or stark blue midday skies populated with bright, puffy clouds. They love to “blind” you with flashing lights and bright colors — often an eye-piercing red. Ironically, these are the things that we as cinematographers have usually stayed away from, preferring instead an interpretation of the visual world around us that is less saturated and not so super-dynamic.

More often, we are looking for subtlety, for mood, for desaturated colors. We tend to be interested in the dark side and shy away from the light — unless, of course, the light is what a particular project calls for. Being confronted so consistently with HDR’s bright side is akin to playing your home stereo only at full amplification. Social consequences aside, you would eventually go deaf! Could HDR similarly make you blind? A friend of mine recently watched a large-screen showing of HDR imagery that weighted its performance for a super-bright image, and yes, his eyes were hurt. After a doctor’s visit, he was ordered to a dark room for 24 hours.

In truth, HDR is not all bad if you properly control it. It has especially caught my interest in its ability to deal with the dark side of the image. A corollary in the art world can be found in Rembrandt’s paintings, which draw your attention to the dark, where the painter’s detail is rich and varied. The black outfits worn by the paintings’ subjects display an enormous variety of densities. There are subtle shades of color, and the fabric, dark as it is, always seems to catch a subtle highlight. Additionally, the white lace collars of the era, representing the paintings’ highest brightness, appear as a muted white, with lots of fine detail.

Previously, that sort of dynamic range was not really possible to replicate in the photographic world. But now, with HDR, we are able to reach into the darkness.

When Roger Deakins, ASC, BSC graded Blade Runner 2049 for HDR, he made sure the detail in the darkness was rich and vivid, and he downplayed the brightness of the transfer. The result showed me that a cinematographically satisfying approach to HDR is possible after all. But, yes, it requires the complete involvement of the cinematographer to oversee the process.

Without that involvement, I’m afraid we will be left with a world of the blind, where the one-eyed will be king.

Kees van Oostrum
ASC President

And again FYI

Originally Posted by puddy77

For San Diego Comic Con, American Cinematographer is giving away free three month digital subscriptions to their magazine just by signing up for their newsletter. It includes their archives.

https://mailchi.mp/ascmag/ac-sd2018

[Geoff D]

Ugh, more HDR fud. Not surprised its from AC though, as they've always been a bit on the traditional side of things.

[Geoff D]

Originally Posted by alexanderg823

Does BD100 offer a bitrate advantage in terms of bandwidth over BD66?

Is that much space necessary for movies under 2 hours?

In terms of actual bitrate available for the content the 66 and 100GB flavours share the exact same specs in terms of what the maximum bitrate can be e.g.



A double-decker is fine for a 2-ish hour movie as long as it isn't laden with extra audio tracks well into the double figures, but as certain studios are often looking to provide a "one size fits all" disc then they will switch to a triple-stacker to accommodate those extra language tracks, e.g. Sony's The Equaliser. If they are also including extras on the 4K discs (Lionsgate, and more recently Sony again) then that also means a 100GB is preferable.

[Fendergopher]

It's also important to not forget how many UHD releases look good if not great on BD66 discs, with some others on BD100 having issues despite theoretically having more than enough breathing room. Take Groundhog Day which is on a BD66 but looks great and has plenty of grain. It really comes down to the skill of the encoding crew and how good the source is, as should be apparent with how some 1080p BD50's can arguably look better if the UHD is goofed.

[DisplayCalNoob]

Originally Posted by alexanderg823

Does BD100 offer a bitrate advantage in terms of bandwidth over BD66?

Is that much space necessary for movies under 2 hours?

BD100 gets you 130 Mbits/s. DCI bit rate is up to 250 Mbits/s.

BD66 gets you 108 Mbits/s, the higher the bit rate, the less compression used.

UHD resolution uncompressed, brings the bit rate up to 700 Mbits/s

4K intermediate means 4096 x 2160p, that's down scaled to UHD resolution. Once compression is added, there's less image information to process.

BD100 storage capacity and bit rate would allow for less compression. BR 2049 and Transformers TLK are on BD100 disc, both have amazing image detail, where things up close and in the distance are sharp and detailed.

[alexanderg823]

Originally Posted by DisplayCalNoob

BD100 gets you 130 Mbits/s. DCI bit rate is up to 250 Mbits/s.

BD66 gets you 108 Mbits/s, the higher the bit rate, the less compression used.

UHD resolution uncompressed, brings the bit rate up to 700 Mbits/s

4K intermediate means 4096 x 2160p, that's down scaled to UHD resolution. Once compression is added, there's less image information to process.

BD100 storage capacity and bit rate would allow for less compression. BR 2049 and Transformers TLK are on BD100 disc, both have amazing image detail, where things up close and in the distance are sharp and detailed.

DCI doesn't use HEVC, so the mbit comparison is invalid. 127 mbit HEVC vs 250 mbits DCI JPEG 2000 is apples and oranges. Furthermore it gets more muddled in high frame rate content, such as billy lynn, which is still limited to the same 127 mbit cap on UHD blu whereas it increases to 500 mbit on DCI.

I appreciate what you're saying, but my point was I didn't think the disc size mattered in max bandwidth, meaning peak bitrate is irrelevant of disc size.
And more so questioning whether or not BD66 provides sufficient space for movies under a certain time duration to provide an HEVC encoding as transparent to the DCI file as possible.

[PeterTHX]

Originally Posted by Geoff D

A double-decker is fine for a 2-ish hour movie as long as it isn't laden with extra audio tracks well into the double figures, but as certain studios are often looking to provide a "one size fits all" disc then they will switch to a triple-stacker to accommodate those extra language tracks, e.g. Sony's The Equaliser. If they are also including extras on the 4K discs (Lionsgate, and more recently Sony again) then that also means a 100GB is preferable.

Equalizer also had extras. Lionsgate uses BD-100 to add extras to their releases too.


I think there is actually a higher bitrate allowed for BD-100 and those extra language tracks take that extra bandwidth (25Mbps-ish).

[Geoff D]

Originally Posted by PeterTHX

Equalizer also had extras. Lionsgate uses BD-100 to add extras to their releases too.

That's why I put "Lionsgate, and more recently Sony again" in parentheses after mentioning them there extras in relation to 100GB discs.

I think there is actually a higher bitrate allowed for BD-100 and those extra language tracks take that extra bandwidth (25Mbps-ish).

Nope. Exact same 'peak' bitrates are permitted on both 66 and 100GB. It's right there in the image above which is from the UHD BD white paper. But the 100GB disc will naturally give you more room to operate if you are judicious with the video bitrate and allow enough of an overhead to cram those tracks on there, as well as the space it affords for extras which are separate from the main transport stream, natch.

[Geoff D]

Originally Posted by DisplayCalNoob

BD100 gets you 130 Mbits/s. DCI bit rate is up to 250 Mbits/s.

BD66 gets you 108 Mbits/s, the higher the bit rate, the less compression used.

Nope nope nope nope nope. It's a myth that BD66 and BD100 are capped at different peak bitrates because those bitrates are governed by the 33GB layers, NOT how many of those layers are used. BOTH CAN USE THE 128 Mb/s MAX VIDEO BITRATE. Seriously, guys, it's right there in black and white (plus a little bit of blue) above. Can't make it much clearer than that.

[DisplayCalNoob]

Originally Posted by alexanderg823

DCI doesn't use HEVC, so the mbit comparison is invalid. 127 mbit HEVC vs 250 mbits DCI JPEG 2000 is apples and oranges. Furthermore it gets more muddled in high frame rate content, such as billy lynn, which is still limited to the same 127 mbit cap on UHD blu whereas it increases to 500 mbit on DCI.

I appreciate what you're saying, but my point was I didn't think the disc size mattered in max bandwidth, meaning peak bitrate is irrelevant of disc size.
And more so questioning whether or not BD66 provides sufficient space for movies under a certain time duration to provide an HEVC encoding as transparent to the DCI file as possible.

Your right, but if a studio is planning on pressing a BD66 disc with a nearly 3 hour film with a 130 Mbits/s, UHD Resolution, and HDR on it. Bit rate will take a hit.

With some Google searching I've done on the issue, HDR is another challenge in relation to bit rate. HDR adds to the bit rate requirement, if you consider highlight detail.

Personally, I prefer the headroom for HDR. I wouldn't be surprised if low bit rates have an affect on color volume, causing posterization in saturated bright colors.

[Geoff D]

HDR is a challenge to compress not so much in terms of peak headroom but because the PQ EOTF uses less bit-depth for its highlights and lowlights than what gamma does, you've potentially got a lot of range crammed into only a few bits so it needs care and attention to stop them highlights exploding into showers of artefacts, particularly when using HDR10 as the 10-bit depth is above the Barten threshold for banding when using PQ.

Going to 11 bits or higher is where more protection from banding comes into play which is why Dolby Vision is a 12-bit system, though genuine 12-bit DV masters are harder to come by because of a lot of sources were/are mastered at 10-bit.

[DisplayCalNoob]

Originally Posted by Geoff D

Nope nope nope nope nope. It's a myth that BD66 and BD100 are capped at different peak bitrates because those bitrates are governed by the 33GB layers, NOT how many of those layers are used. BOTH CAN USE THE 128 Mb/s MAX VIDEO BITRATE. Seriously, guys, it's right there in black and white (plus a little bit of blue) above. Can't make it much clearer than that.

Yeah, saw it after I posted. I stand corrected.

[JohnAV]

Originally Posted by puddy77

DCI Takes First Step to Define HDR Cinema

https://www.displaydaily.com/article...ine-hdr-cinema

More info is available at this URL

DCI Memorandum Regarding Direct View Displays
Approved 27 June 2018

[gkolb]

Status of HDMI 2.1 posted over in the Panasonic UB820/UB9000 w/HCX video processor & dynamic conversion adjustment thread.

Originally Posted by Robert Zohn

No current TV, BD player or any a/v device can be upgraded to the full HDMI 2.1 spec. Some HDMI 2.0a and HDMI 2.0b devices can be upgraded to meet a few of the HDMI 2.1 specs. However no HDMI 2.0 chip will ever be capable of bandwidth beyond 18Gbps.

When HDMI 2.1 chips sets become available they will support 48Gbps and all of the future advancement that are many years ahead, like 8k resolution, full BT.2020 color gamut, 120fps with 4:4:4 color sampling and more.

Keep in mind that Hollywood's latest state-of-the-art has not gone beyond P3 DCI color and no one has even suggested what year we might see content created and mastered in BT2020 color.

As usual, really good stuff from Robert.

[mrtickleuk]

Originally Posted by puddy77

An opinion piece from the President's Desk in the August 2018 American Cinematographer:

"A friend of mine recently watched a large-screen showing of HDR imagery that weighted its performance for a super-bright image, and yes, his eyes were hurt. After a doctor’s visit, he was ordered to a dark room for 24 hours."

I don't believe him. An anecdote is NOT evidence and is not scientific. FUD in its purest forum.

Quiz question. If you listen to music at a concert and it's too loud and you don't cover your ears, whose fault is it?
a) The person who designed and built the speakers,
b) the person with his finger on the volume knob,
c) or maybe is it you who needs to take some responsibility for your own actions, and cover your ears or leave the venue?

[DanBa]

What
"Dolby Vision? HDR10+? Dolby makes the case that both can coexist.
Giles Baker, Dolby Laboratories’ Senior Vice President of Consumer Entertainment, mused about a future in which both systems coexist. Granted, he believes Dolby provides a better end-to-end solution for HDR mastering and delivery, but that doesn’t mean he thinks HDR10+ doesn’t have its merits. It’s just … different.
There doesn’t need to be a winner and a loser here - we should all just enjoy better-looking content in whichever format directors and creators choose to use."*
https://www.techradar.com/news/dolby...u-to-have-both

How
"Bill Mandel, industry relations VP for Samsung Research and program manager for HDR10+ for Samsung Electronics, said that despite the existence of a half dozen different HDR profiles, all will coexist through the use of Extended Display Information Data (EDID) technology that will let HDR10+ enabled players, televisions and even AV receivers communicate back and forth. That way HDR10+ info frame data can be delivered or withheld by the player if the display device or receiver are not compatible. Additionally, the devices might send a pop up asking the user which form of HDR is preferred when more than one is present.
That way all of the different systems can coexist without conflicts."
https://hdguru.com/hdr10-looks-for-g...tent-hardware/

When
The coexistence of different HDR profiles would be likely to be officially endorsed by a 8K standard-setting body.

"One of the things that the consumer electronics industry is historically very bad at is introducing new standards to the public.*At one point, HD had well over 30 different flavours in use worldwide and plenty of TV sets sold as HD Ready (if you can remember that far back) turned out to be no such thing.*And, to be honest, the introduction of 4K has hardly been much better, while even HDR is not the cut and dried, 'this TV does HDR, this TV doesn't' case it should be either.
Speaking at the annual QLED & Advanced Display Summit in Hollywood, David Jung from Samsung's Picture Differentiation Lab delivered the following mea culpa.
“We feel we have to sufficiently explain to industry players in the ecosystem, and most importantly, the consumers, the value proposition of 8K.*4K distribution beat market expectations, but we feel now in retrospect we could have done better in setting standards and educating customers in such things as UHD and HDR.”
As a result, Samsung, which was a key member of the UHD Alliance, is in discussion with a variety of industry stakeholders to set up a body looking at the introduction of 8K."
https://www.redsharknews.com/product...mistakes-as-4k

"We feel we have to sufficiently explain to industry players in the ecosystem, and most importantly, the consumers, the value proposition of 8K," he said. "4K distribution beat market expectations, but we feel now in retrospect we could have done better in setting standards and educating customers in such things as UHD (ultra high definition) and HDR (high dynamic range)."
"Resolution is important, but today TV needs to offer added values besides just resolution," said Jung. "To do so, we believe we must cooperate with all stakeholders in the ecosystem, including content makers and distributors. We are keeping an open mind."
We need a different mindset from the past decade where TV manufacturers competed on shipment fiercely, to the detriment of our bottom lines," the official added. "We need to justify to consumers why they should consider 8K over a 4K TV as we can only do that when the industry as a whole come together to foster the ecosystem."
https://www.zdnet.com/article/samsun...-setting-body/

[Geoff D]

I've said the same things about the rollout of HD, we look back at it now with rose-tinted glasses but it was a right old mess. Not to justify the even greater cluster**** that HDR has been, and still is, but I've been here before which is why I don't get as miffed as some people do about 4K.

[Fendergopher]

Originally Posted by Geoff D

I've said the same things about the rollout of HD, we look back at it now with rose-tinted glasses but it was a right old mess. Not to justify the even greater cluster**** that HDR has been, and still is, but I've been here before which is why I don't get as miffed as some people do about 4K.

One could at least argue that the potential benefits of 4K/HDR outweigh a lot of the issues that we see with implementation, as opposed to if it was simply a higher resolution. 10(12)Bit, WCG, HDR & 4K offers a lot more than simply a sharper image with less compression, and considering how every new home video format has had problems it should come as no surprise that this new generation will hit quite a few bumps in the road to smooth operation.

Still doesn't excuse issues like the metadata farce going on, or how displays are all over the place as far as their HDR capabilities go, with manufactorers vying to jump on 8K before they've even made watching movies with dynamic metadata easy and convenient. Basically the technology is outpacing both the market and the studios at a rapid pace, workflows tend to change painfully slowly.

[ray0414]

Originally Posted by mrtickleuk

"A friend of mine recently watched a large-screen showing of HDR imagery that weighted its performance for a super-bright image, and yes, his eyes were hurt. After a doctor’s visit, he was ordered to a dark room for 24 hours."

I don't believe him. An anecdote is NOT evidence and is not scientific. FUD in its purest forum.

Quiz question. If you listen to music at a concert and it's too loud and you don't cover your ears, whose fault is it?
a) The person who designed and built the speakers,
b) the person with his finger on the volume knob,
c) or maybe is it you who needs to take some responsibility for your own actions, and cover your ears or leave the venue?

Sounds like BS. Does this person not go outside? Or have a medical condition? Seriously, driving at night time headlights and break lights are now brighter than tvs are.

One time this jerk was driving with his brights on a d blinded me, and I had to go to the hospital. Said nobody ever.