SMPTE ST2084 (PQ): Elements of HDR-Videos

Yelandkeil wrote on 3/26/2021, 2:35 PM


Not few people are very confused about HDR, and hence, take every wrong steps to set the ACES editing environment for performance. 
There are even people who don't know what's between ACES and 32-bit floating point full-range-space. 

Here we try understanding HDR, firstly!

1, 
High Dynamic Range is merely an added metadata by rendering videos based on WCG (wide color gamut).

Traditional standard videos, as you know, show their picture in 16-235 levels (8bit color depth). 
Poor brightness and rough/narrow colorspectrum is the result as you watch your video on TV or in computer.

WCG-videos obtain more than 1 billion colors (10bit depth with 64-940 levels) so that their picture provides very delicate/fine gray scale even in 8k or bigger resolutions. 
But the brightness, or the dynamic range of the luminance, is not much better than the standard ones. 
The reason: limitation of the display production. 

In recent years, Japanese/Korean engineers have made a big breakthrough in technology. You must be shocked at watching HDR-videos on OLed-screen or what else it's called. 
And all these screens have one parameter: xxxxCD/m2 (how many candles light intensity in one squaremeter). 
Nit is its official name. 

The new panel displays thunderbolt and moonlight so natural as your eyes see in the nature. 
Yes, it can give the lightning up to or even above 1000nits!
And in pure darkness you still can hunt details. 
Because the video signal trans-codes the HDR-metadata to realize the nit-strength just as your eye pupils deal with your surroundings. 
This render method is called Perceptual Quantizer and often showed as SMPTE ST 2084(PQ) under the WCG. 

**HDR requires hardware at least with 300cd/m2.
**RENDER is not only process you put your timeline out to file. 
**Trancode/translate a signal onto the display panel is also rendering.

If a WCG-display does not understand HDR-metadata, it treats the WCG-videosignal in simplest way, say, in the 64-940 levels of the 10bit color. 
You get fine picture with "standard dynamic range".

So, at purchasing your new WCG equipment be sure it supports HDR. 
Abbildung: 2 screens with/without HDR support (see Panel)


2, 
Wide Color Gamut is just an expression. 

As hardware definition, every monitor that has 10bit depth (8+2 FRC is OK, too), and covers at least the P3-DCI area, is a WCG-monitor. 

Abbildung basic knowledge: the horseshoe-shaped spectrum is the color area human eyes can see, various hardware can only present part of it, and every PART is called A colorspace. 

3,
Windows 10 default color space is sRGB, which is also the standard color space for network communication/exchange and programs if not specially indicated. 

Windows 10  supports seamlessly WCG and HDR as long as your graphic card is not an old scum.
If you own a WCG monitor with HDR, just a few clicks lead you enjoying many wonderful videofilms at Y-Tube. 

And you will notice that those unreal richcolored image-icons come back to normal all at a sudden. 
This is because the default sRGB management does not understand WCG-monitor.
Illustration: System color settings with HDR-monitor


4, 
SMPTE ST2084 (PQ): Elements of HDR-Videos

Please check the picture parameter -- 
Color: smpte2084 (PQ)/bt2020
If you don't understand, doesn't matter. 
It means: you are looking high dynamic range motion pictures with xxx format in xxx colorspace. 


5. 
I'd like to make a short entry about 32bit floating point full range environment and ACES in Vegaspro18.  
If you have interest. 
But don't know what time. 
Thankyou!

Last changed by Yelandkeil

ASUS TUF Gaming B550plus BIOS3202: 
- Thermaltake TOUGHPOWER GF1 850W 
- ADATA XPG GAMMIX S11PRO; 512GB/sys, 2TB/data 
- G.SKILL F4-3200C16Q-64GFX 
- AMD Ryzen9 5950x + LiquidFreezer II-240 
- XFX Speedster-MERC319-RX6900XT <-AdrenalinEdition 24.12.1
Samsung 2xLU28R55 HDR10 (300CD/m², 1499Nits/peak) ->2xDPort
ROCCAT Kave 5.1Headset/Mic ->Analog (AAFOptimusPack 6.0.9403.1)
LG DSP7 Surround 5.1Soundbar ->TOSLINK

Lumix DC-GH6/H-FS12060E: HLG4k60p, AWBw, shutter=100, ISO=auto (250 - 6400)
DJI Mini4 Pro: HLG4k60p, AWB, shutter=auto, ISO=auto, EV-2.0
HERO5: ProtuneFlat2.7k60pLinear, WB=4800K, Shutter=auto, ISO=800

Win11Pro: 24H2-26100.4202; Direct3D API: 12.2
VEGASPro22 + XMediaRecode/Handbrake + DVDArchi7 
AcidPro10 + SoundForgePro14.0.065 + SpectraLayersPro7 
K-LitecodecPack17.8.0 (MPC Video Renderer for HDR10-Videoplayback on PC) 

Comments

adis-a3097 wrote on 3/26/2021, 4:11 PM

As hardware definition, every monitor that has 10bit depth (8+2 FRC is OK, too), and covers at least the P3-DCI area, is a WCG-monitor. 

How is it that P3 is considered a wide color gamut and sRGB is not when sRGB is spec'd with 80 nits and P3 with 48 (actually, being a DCI thing, it's 14 fL, which only states the strength of the light flux per area, not taking the screen's reflectance coefficient, and therefore disregarding the achieved shininess of the screen, into consideration)? I mean sRGB's got a bigger light budget. :)

Thanks!

Yelandkeil wrote on 3/26/2021, 4:44 PM

please focus your eyes to

1, you talk about hardware definition (color space): sRGB/Rec.709 has 8bit depth with 0/16 - 255/235 levels; P3-DCI/Rec.2020 has 10bit depth with 64 - 940 levels. Who tells you what level is how bright and equal which nit? And since when will sRGB, or here accurately, old mode display panel's brightness be calculated in NIT?

2, you talk about expression/declaration of the Color Charakteristikum: Wide Color Gamut is a wide color area bigger than traditional area and dominates at least 10bit color depth. The physical measure is about this much --

thanks for reply.

Last changed by Yelandkeil on 3/26/2021, 4:58 PM, changed a total of 2 times.

ASUS TUF Gaming B550plus BIOS3202: 
- Thermaltake TOUGHPOWER GF1 850W 
- ADATA XPG GAMMIX S11PRO; 512GB/sys, 2TB/data 
- G.SKILL F4-3200C16Q-64GFX 
- AMD Ryzen9 5950x + LiquidFreezer II-240 
- XFX Speedster-MERC319-RX6900XT <-AdrenalinEdition 24.12.1
Samsung 2xLU28R55 HDR10 (300CD/m², 1499Nits/peak) ->2xDPort
ROCCAT Kave 5.1Headset/Mic ->Analog (AAFOptimusPack 6.0.9403.1)
LG DSP7 Surround 5.1Soundbar ->TOSLINK

Lumix DC-GH6/H-FS12060E: HLG4k60p, AWBw, shutter=100, ISO=auto (250 - 6400)
DJI Mini4 Pro: HLG4k60p, AWB, shutter=auto, ISO=auto, EV-2.0
HERO5: ProtuneFlat2.7k60pLinear, WB=4800K, Shutter=auto, ISO=800

Win11Pro: 24H2-26100.4202; Direct3D API: 12.2
VEGASPro22 + XMediaRecode/Handbrake + DVDArchi7 
AcidPro10 + SoundForgePro14.0.065 + SpectraLayersPro7 
K-LitecodecPack17.8.0 (MPC Video Renderer for HDR10-Videoplayback on PC) 

fr0sty wrote on 3/26/2021, 5:01 PM

HDR is about a bit more than just metadata... it is a set of specifications that determine if your hardware is able to properly display WCG. To be certified as true HDR, you need to be able to hit:

0.05 nits to ≥1000 nits for non-OLED

0.0005 nits to ≥540 nits for OLED (OLED gets the lower peak brightness break because it can go so much farther into black. Most OLED sets are in the 500-700 nit brightness range, but lack the ability to hit 1000 or above nits. Micro LED will replace OLED soon and fix this issue)

The HDR spec actually supports up to 10,000 nits for 10 bit. Then there's 12 bit Dolby Vision.

Last changed by fr0sty on 3/26/2021, 5:03 PM, changed a total of 1 times.

Systems:

Desktop

AMD Ryzen 7 1800x 8 core 16 thread at stock speed

64GB 3000mhz DDR4

Geforce RTX 3090

Windows 10

Laptop:

ASUS Zenbook Pro Duo 32GB (9980HK CPU, RTX 2060 GPU, dual 4K touch screens, main one OLED HDR)

Yelandkeil wrote on 3/26/2021, 5:38 PM

@fr0sty, thank you!

I'm Chinese. If you say China is a beautiful country, I'd also like saying:

China is about a bit more than just a beautiful country...its HISTORY...let me collect all the statistics from side of the People's Republic of China in the mainland and the Republic of China in Taiwan.

Meanwhile please prepare things from Japan and Korea for me.

Just kidding, pls be large-minded.

ASUS TUF Gaming B550plus BIOS3202: 
- Thermaltake TOUGHPOWER GF1 850W 
- ADATA XPG GAMMIX S11PRO; 512GB/sys, 2TB/data 
- G.SKILL F4-3200C16Q-64GFX 
- AMD Ryzen9 5950x + LiquidFreezer II-240 
- XFX Speedster-MERC319-RX6900XT <-AdrenalinEdition 24.12.1
Samsung 2xLU28R55 HDR10 (300CD/m², 1499Nits/peak) ->2xDPort
ROCCAT Kave 5.1Headset/Mic ->Analog (AAFOptimusPack 6.0.9403.1)
LG DSP7 Surround 5.1Soundbar ->TOSLINK

Lumix DC-GH6/H-FS12060E: HLG4k60p, AWBw, shutter=100, ISO=auto (250 - 6400)
DJI Mini4 Pro: HLG4k60p, AWB, shutter=auto, ISO=auto, EV-2.0
HERO5: ProtuneFlat2.7k60pLinear, WB=4800K, Shutter=auto, ISO=800

Win11Pro: 24H2-26100.4202; Direct3D API: 12.2
VEGASPro22 + XMediaRecode/Handbrake + DVDArchi7 
AcidPro10 + SoundForgePro14.0.065 + SpectraLayersPro7 
K-LitecodecPack17.8.0 (MPC Video Renderer for HDR10-Videoplayback on PC) 

adis-a3097 wrote on 3/26/2021, 6:38 PM

please focus your eyes to

1, you talk about hardware definition (color space): sRGB/Rec.709 has 8bit depth with 0/16 - 255/235 levels; P3-DCI/Rec.2020 has 10bit depth with 64 - 940 levels. Who tells you what level is how bright and equal which nit? And since when will sRGB, or here accurately, old mode display panel's brightness be calculated in NIT?

2, you talk about expression/declaration of the Color Charakteristikum: Wide Color Gamut is a wide color area bigger than traditional area and dominates at least 10bit color depth. The physical measure is about this much --

thanks for reply.

sRGB specs tell me, who else? :)

4. Reference display white point luminance: 80 cd/m2

https://www.w3.org/Graphics/Color/srgb

80 is sRGB, 48 is P3.

 

"sRGB" is monitor spec, it's not the bits that make color gamut wide, it's the output devices. 10 bit is 10 bit, it only says how much integer values there are, nothing more. :)

Yelandkeil wrote on 3/27/2021, 1:09 AM

@adis-a3097, you are right. I am wrong.

sRGB is brighter than P3.

sRGB is WCG, P3 not.

It is, as the German used say, man lernt nie aus.

Thanks lot. My brain doesn't work like Albert. Mostly, if I cannot catch the keypoint, I ask for an illustration to explain. And this time I got the wrong one --

Or we are constantly not at one topic.

I talk about color gamut declaration and hardware definition that it must reach a certain color display range/area/gamut.

you talk about How to interpret the sRGB color space (specified in IEC 61966-2-1) for ICC profiles

your interpret/calculate is convincing.

Last changed by Yelandkeil on 3/27/2021, 1:46 AM, changed a total of 3 times.

ASUS TUF Gaming B550plus BIOS3202: 
- Thermaltake TOUGHPOWER GF1 850W 
- ADATA XPG GAMMIX S11PRO; 512GB/sys, 2TB/data 
- G.SKILL F4-3200C16Q-64GFX 
- AMD Ryzen9 5950x + LiquidFreezer II-240 
- XFX Speedster-MERC319-RX6900XT <-AdrenalinEdition 24.12.1
Samsung 2xLU28R55 HDR10 (300CD/m², 1499Nits/peak) ->2xDPort
ROCCAT Kave 5.1Headset/Mic ->Analog (AAFOptimusPack 6.0.9403.1)
LG DSP7 Surround 5.1Soundbar ->TOSLINK

Lumix DC-GH6/H-FS12060E: HLG4k60p, AWBw, shutter=100, ISO=auto (250 - 6400)
DJI Mini4 Pro: HLG4k60p, AWB, shutter=auto, ISO=auto, EV-2.0
HERO5: ProtuneFlat2.7k60pLinear, WB=4800K, Shutter=auto, ISO=800

Win11Pro: 24H2-26100.4202; Direct3D API: 12.2
VEGASPro22 + XMediaRecode/Handbrake + DVDArchi7 
AcidPro10 + SoundForgePro14.0.065 + SpectraLayersPro7 
K-LitecodecPack17.8.0 (MPC Video Renderer for HDR10-Videoplayback on PC) 

RogerS wrote on 3/27/2021, 2:42 AM
 

sRGB is WCG, P3 not.

If WCG = wide color gamut, that contradicts the two earlier posts you made that showed plots of the different color spaces. Rec 709 an sRGB were the smallest shown and P3 was larger than sRGB but smaller than Rec 2020.

Yelandkeil wrote on 3/27/2021, 3:48 AM

sRGB is WCG, P3 not.

-- It's not my conclusion, sir.

WCG consists it's bigger than traditional video color space (including the none video but computer space standardRGB).

WCG doesn't care who should be included and how large they must be. That's the job of engineers.

I'm afraid it's worth to go planning any thing about 32-bit floating point or ACES.

Thanks for your reply.

ASUS TUF Gaming B550plus BIOS3202: 
- Thermaltake TOUGHPOWER GF1 850W 
- ADATA XPG GAMMIX S11PRO; 512GB/sys, 2TB/data 
- G.SKILL F4-3200C16Q-64GFX 
- AMD Ryzen9 5950x + LiquidFreezer II-240 
- XFX Speedster-MERC319-RX6900XT <-AdrenalinEdition 24.12.1
Samsung 2xLU28R55 HDR10 (300CD/m², 1499Nits/peak) ->2xDPort
ROCCAT Kave 5.1Headset/Mic ->Analog (AAFOptimusPack 6.0.9403.1)
LG DSP7 Surround 5.1Soundbar ->TOSLINK

Lumix DC-GH6/H-FS12060E: HLG4k60p, AWBw, shutter=100, ISO=auto (250 - 6400)
DJI Mini4 Pro: HLG4k60p, AWB, shutter=auto, ISO=auto, EV-2.0
HERO5: ProtuneFlat2.7k60pLinear, WB=4800K, Shutter=auto, ISO=800

Win11Pro: 24H2-26100.4202; Direct3D API: 12.2
VEGASPro22 + XMediaRecode/Handbrake + DVDArchi7 
AcidPro10 + SoundForgePro14.0.065 + SpectraLayersPro7 
K-LitecodecPack17.8.0 (MPC Video Renderer for HDR10-Videoplayback on PC) 

fr0sty wrote on 3/27/2021, 4:06 AM

sRGB basically is Rec709, the two are very similar. Rec2020 and similar spaces (AdobeRGB etc.) is what we know of as WCG.

Last changed by fr0sty on 3/27/2021, 4:08 AM, changed a total of 1 times.

Systems:

Desktop

AMD Ryzen 7 1800x 8 core 16 thread at stock speed

64GB 3000mhz DDR4

Geforce RTX 3090

Windows 10

Laptop:

ASUS Zenbook Pro Duo 32GB (9980HK CPU, RTX 2060 GPU, dual 4K touch screens, main one OLED HDR)

adis-a3097 wrote on 3/27/2021, 4:07 AM

@adis-a3097, you are right. I am wrong.

sRGB is brighter than P3.

sRGB is WCG, P3 not.

It is, as the German used say, man lernt nie aus.

Thanks lot. My brain doesn't work like Albert. Mostly, if I cannot catch the keypoint, I ask for an illustration to explain. And this time I got the wrong one --

Or we are constantly not at one topic.

I talk about color gamut declaration and hardware definition that it must reach a certain color display range/area/gamut.

you talk about How to interpret the sRGB color space (specified in IEC 61966-2-1) for ICC profiles

your interpret/calculate is convincing.

 

Es lernt der Mensch, solang er lebt. :)

 

sRGB is WCG, P3 not.

If WCG = wide color gamut, that contradicts the two earlier posts you made that showed plots of the different color spaces. Rec 709 an sRGB were the smallest shown and P3 was larger than sRGB but smaller than Rec 2020.

Of course it contradicts - all that contradictory info is coming from the net, not from him directly.

Net's full of it... :)

Yelandkeil wrote on 3/27/2021, 4:14 AM

Es lernt der Mensch, solang er lebt.😍

kann man auch chinesisch?

Apropos: Hier sind 2 Bildschirme, beide gehören/entsprechen dem sRGB-Farbraum (sprich: color space/definition that hardware should obey or at least be compatible to).

Der eine sagt stolz mit seiner Farb(raum)-Spezifikation: Ich überdecke 99% (sRGB).

Der andere lässt es blanko und sagt ohne Miene: Trotzdem bin ich auch ein sRGB-Bildschirm.

Last changed by Yelandkeil on 3/27/2021, 4:57 AM, changed a total of 4 times.

ASUS TUF Gaming B550plus BIOS3202: 
- Thermaltake TOUGHPOWER GF1 850W 
- ADATA XPG GAMMIX S11PRO; 512GB/sys, 2TB/data 
- G.SKILL F4-3200C16Q-64GFX 
- AMD Ryzen9 5950x + LiquidFreezer II-240 
- XFX Speedster-MERC319-RX6900XT <-AdrenalinEdition 24.12.1
Samsung 2xLU28R55 HDR10 (300CD/m², 1499Nits/peak) ->2xDPort
ROCCAT Kave 5.1Headset/Mic ->Analog (AAFOptimusPack 6.0.9403.1)
LG DSP7 Surround 5.1Soundbar ->TOSLINK

Lumix DC-GH6/H-FS12060E: HLG4k60p, AWBw, shutter=100, ISO=auto (250 - 6400)
DJI Mini4 Pro: HLG4k60p, AWB, shutter=auto, ISO=auto, EV-2.0
HERO5: ProtuneFlat2.7k60pLinear, WB=4800K, Shutter=auto, ISO=800

Win11Pro: 24H2-26100.4202; Direct3D API: 12.2
VEGASPro22 + XMediaRecode/Handbrake + DVDArchi7 
AcidPro10 + SoundForgePro14.0.065 + SpectraLayersPro7 
K-LitecodecPack17.8.0 (MPC Video Renderer for HDR10-Videoplayback on PC) 

RogerS wrote on 3/27/2021, 5:55 AM

Not sure if this thread is misinformation or disinformation but not finding much of value regarding ACES or HDR.