technology update better pixels

Why and how to go to Ultra HD phase 2

Maryline CLARE, Orange Labs

Jérôme VIERON, ATEME For Enhanced Video ExpeRience

Summary

• 4EVER-2: description and methods

• UHD-TV phase 2: the real gap in quality of experience

• Focus on HDR – what is HDR

– several technical solutions and standardization committees

– subjective tests

– 4EVER-2 trials

www.4ever-2.com 4EVER-2 : go for UHD-TV phase 2! 2

• HFR: – what it is

– subjective tests

• compressor challenges – HDR

– HFR

• The first UHD-TV phase 2 + NextGen audio production = 4EVER short

• Conclusions, perspectives

What is 4EVER-2?

What do we work on? How?

www.4ever-2.com 3 4EVER-2 : go for UHD-TV phase 2!

4EVER: All about visual quality of TV content

www.4ever-2.com 4

spatial definition (4K)

Quality of Experience?

UHD-TV phase 2

UHD-TV phase 1

Extended colors (Wide Color Gamut, WCG)

Temporal definition (High Frame Rate, HFR)

Contrast definition (High Dynamic Range, HDR)

4EVER-2 : go for UHD-TV phase 2!

4EVER-2 structural keypoints • Consortium and its 9 partners known (4EVER): active contribution to standardization

bodies, TV professional services, …

• Complementary skills over the whole end-to-end audiovisual chain

• Lab research experimented in real premium events (sports, culture)

• Integration of the audio dimension for a real audiovisual quality content evaluation

• Collaboration with worldwide major actors

– Groups and forums : EBU, BBC, IRT, HD Forum

– Consumer and professional equipment manufacturers


Nine French partners

4EVER-2 : go for UHD-TV phase 2! 6 www.4ever-2.com

Shooting Production Encoding Contribution Distribution

Decoding Playing

Perceived quality

on end-to-end audiovisual chain

4EVER-2: the end-to-end AV chain


• Orange Labs: coordination, audiovisual assessment tests

• francetélévisions: content production, joined audio visual subjective tests

• AMPVisualTV: live production workflows , UHD-TV equipment evaluation,

• ATEME: HEVC encoding of UHD-TV phase 2 (HDR and/or HFR and/or WCG)

• INSA-IETR: HEVC decoding of UHD-TV phase 2 (OpenHEVC open source)

• HTS: colorimetry science

• Télécom ParisTech: HEVC player (GPAC open source), HDR quality assessement, rendering HDR depending on viewing room conditions

• TeamCast: terrestrial and satellite TV transmission (DVB-T2, DVB-S2X)

• GlobeCast: technical infrastructure for end-to-end content distribution (satellite, IPTV)

1/Experimental shooting sessions • Evaluate production equipments and complete workflow

• Generate ultra high quality sequences with controled parameters


1/Sequences shared worldwide


2/Evaluation of video perceived quality

• Display parameters: brightness, contrast

• In the room: light control around the display

• Distance to the screen

• SAMVIQ method (ITU-R BT 1788): adapted to evaluation of video quality on short sequences

• 25 to 20 non expert observers

• SEOVQ software

Subjective tests in standardized environment (REC ITU-R BT.500)

4EVER-2 : go for UHD-TV phase 2! 10 www.4ever-2.com

3/Research and software development

• Colorimetry: science of color

• Research and development

– HEVC encoding • Professional prototypes for encoder: ATEME

– HEVC decoder • Academic research and open source for decoder : INSA-IETR (open HEVC)

– Video player: Télécom ParisTech (GPAC) • Academic research and open source to integrate HEVC decoding and

UHD-TV specificities


4/Experiment on visible events


Go on actual premium events to experiment prototype audiovisual end-to-end chain

Stressful, but extremely useful!

5/Disseminate results and conclusions

4EVER-2 : go for UHD-TV phase 2! 13

September 2015

On EBU booth, demonstrating HDR in collaboration with BBC

HFR in collaboration with EBU, BBC, IRT, RAI

www.4ever-2.com



April 2014

UHD-TV in OTT internet HEVC + 4K + DASH + HTML5

for a smooth adaptation of bitrate

(hence quality) to bandwidth variations

UHD-TV for DTT

HEVC + 4K + DVB-T2


4EVER-2 : go for UHD-TV phase 2! 15

September 2014

back then, the first and only booth to demonstrate all 4 technologies of

UHD-TV

www.4ever-2.com


• Major communication events in 2016

– MIPTV 2016, Cannes France, April

– NAB 2016, selected for Future Labs Park

• Demonstrations : HFR, HDR, ATSC, 4K, HEVC, live, …

• Please visit

– IBC 2016?

• If interesting demonstrations to propose

• If selected for Future Zone…


Ultra HD-TV phase 2

What for?


Why a need for WCG, HDR and HFR? 4K not « better enough » in normal TV viewing conditions

www.4ever-2.com 18

but only when sitting at

1,5*height of the display

SD HD UHD

Very good

Good

Fair

Bad

Very Bad

JVC Pro Vérité 84" - Toshiba 55" (1.5H)

55"

84"

SD HD UHD

Very good

Good

Fair

Bad

Very Bad

JVC Pro Vérité 84" - Toshiba 55" (3H)

55"

84"

1,5m

1m

UHD

1m

3m HD

10 points better on a scale of 100


HFR: always better even at same bitrate

www.4ever-2.com 19

100Hz native contents provide better quality than 50Hz native contents (about 15 points)


work done in collaboration with

• 100Hz native: much better perceived video

quality than 50Hz native ones

• The performance of Interpolation (MCFI)

depends on the content’s motion features but

in average, 50Hz interpolated at 100Hz

cannot reach the perceived video quality of

native 100Hz

At the same bitrate, the perceived

quality of a 100Hz source remains

better than a 50Hz source

(interpolated or not)

HDR: a real benefit expected Actual improvement potential if conditions are respected

4ever subjective tests results - 2014

www.4ever-2.com 20

Maximum of comfort obtained between 750 and

1500 cd/m²

Perceived video quality increases with peak

luminance level (20 points between

300 and 1500 cd/m2)


HDR: a good improvement… soon? High Dynamic Range: sequences look more natural, sensation of immersion

– Better contrasts: better dark areas, better bright areas


Focus on HDR


23 www.4ever-2.com

High Dynamic Range (HDR)

• Increased contrast • Bright areas (e.g. > 1000 nits) , Dark areas (e.g. < 0.001 nits)

• Luminance range rendering closer to the real world luminance range

• HDR vs SDR higher gain than UHD vs HD • Perceived video quality increases with peak luminance level

High Dynamic Range Standard Dynamic Range

Simulation

1 nit = 1 candela/m2


24 www.4ever-2.com

Today’s Standard Dynamic Range (SDR)

24

~ 0,2 – 1

Lux

> 30 000

OETF: Opto-Electrical Transfer Function

EOTF: Electro-Optical Transfer Function

Lum in cd/m2 or nits

8 bits signal


25 www.4ever-2.com

OETF, EOTF & OOTF

Scene Luminance (min. 10-6 nits / max. 108 nits)

Display Luminance (min. 10-3 nits / max. > 103

nits)

Electro-Optical Transfer Function

(EOTF)

Opto-Electronical Transfer Function

(OETF)

Opto-Optical Transfer Function (OOTF)


26 www.4ever-2.com

HDR: “New” Opto Electronic Transfer Function (OETF)

• “Old” gamma correction => Not well-adapted to wider dynamic range

• PQ (Perceptual Quantizer - SMPTE ST 2084) => Luminance vs Code Value (display referred)


27 www.4ever-2.com

HDR: Grading and Settings

• Color grading (tuning RGB levels, Hue, Brightness, Saturation, and Contrast) => Artistic intent

• HDR content color grading relies on a set of parameters • Which OETF? ST-2084, HLG or proprietary Transfer Function

• Color gamut or primaries? BT 709, P3, BT 2020, XYZ,…

• White primaries? C, D65,…

• Min brightness value?

• Max brightness value?

• Grading monitor characteristics?

To make the viewing experience match the original “Artistic intent”, HDR color grading information must be known at the display side: metadata

Sources: BlackMagic Davinci Resolve


28 www.4ever-2.com

HDR: what about backward compatibility?

• HDR backward compatibility with SDR is an hot topic!

• Several meanings! • Same workflows? cameras, encoders, post-production, etc… • Same spatial resolution? Same bitdepth?

• What is the real need? • One HDR signal directly watchable on any SDR display • One signal from which we can extract both HDR and SDR signal • One HDR signal and one SDR signal simulcasted

• 2 answers: • Compatibility with UHD phase 1 • Compatibility with “today” HDTV (HD,709)


29 www.4ever-2.com

HDR in a nutshell

• New Transfer Function • To better match human visual perception at high luminance

• HDR video signal grading • Color Gamut/primaries and grading based on OETF/EOTF

• Backward compatibility

• Metadata? • Artistic intent: to properly render the HDR signal whatever the technical characteristics

of your HDR display

• Backward compatibility: to reconstruct HDR and/or SDR signal from the encoded content


30 www.4ever-2.com

Alternative HDR Solutions • In addition to HDR10/PQ: Philips, Technicolor, Dolby and, NHK/BBC alternative solutions

• OETF: New transfer functions

• Single or Dual layer

• Metadata (static, dynamic)

• SDR (Standard Dynamic Range) backward compatibility

Provider OETF Method Metadata Backward

Compatible Layers

1 BDA/HDR 10 PQ HDR (SL) Static No Single

2 BBC/NHK HLG OETF (SL) No Yes Single

3 Philips/Technicolor -1 PQ HDR (BL) Static + Dynamic Yes (with IP) Single

4 Philips/Technicolor-2 PQ SDR (BL) Static + Dynamic Yes Single

5 Dolby Vision-1 PQ HDR (BL) +EL Static + Dynamic Yes (with IP) Dual

6 Dolby Vision-2 PQ SDR (BL) + EL Dynamic Yes (with IP) Dual


31 www.4ever-2.com

On HLG - Hybrid Log-gamma

• Transfer function proposed by BBC/NHK (Scene referred)

EOTF: PQ vs BT 1886 (SDR) vs HLG


32 www.4ever-2.com

HDR Eco-System Standardization Status (1/2)

• OETF • PQ - SMPTE ST 2084

• HLG- ARIB STD-B67

• Metadata • SMPTE ST 2086: define standard color grading display metadata

• SMPTE ST 2094: dynamic metadata describing transformation HDR <->SDR (On-going)

• HDMI • 2.0a: Support standard ST 2084 + metadata ST 2086

• 2.1: Hybrid Log Gamma (HLG), ST 2094 ?

• IMF • metadata ST 2086 support soon


33 www.4ever-2.com

HDR Eco-System Standardization Status (2/2)

• Blu-Ray Disc Association (BDA) • HDR 10: HEVC main 10-bits + ST-2084 + ST-2086 Metadata

• Optional: Proprietary metadata: Dolby, Philips, Technicolor

• Compression and application standardization • MPEG/ITU HEVC:

• VUI values for PQ and HLG • SEI messages:

• ARIB: standardized the usage of HLG: STD B67

• DVB: PQ, HLG, Dolby under consideration

Mastering Display Colour Volume (ST 2086),

Chroma resampling filter hint,

Knee function information,

Colour Remapping Information

Content Light Level Information

HDR Compatibility Information


Recent 4EVER-2 HDR live trials

set up real live TV production and distribution


Backward compatibility in TV production

• Main drawback of PQ is that it is not SDR backward compatible – SDR and HDR shall be simulcasted

• The goal is to produce HD 709 + Ultra HD Phase 1 709 or 2020 and add HDR in the same workflow

• With few extra costs !

– no additional cameras

– using current technology (SDI 10 bits …)

– with few extra charge for production teams

• Because TV distribution will remain mostly HD 709 at least for a number of years!


Candidates for TV production in HDR

1. Each camera outputs two (independent) signals – one HD/UHD phase1

– one PQ 10

– vision engineering can optimize SDR and HDR separately

2. Hybrid Log Gamma – HDR and SDR are controled using one video signal

– vision engineering shall optimize SDR and HDR jointly

3. HDR or SDR + Metadata ? – in a static or dynamic way?


1/ Live sport in HDR and HFR Figure ice skating:

HDR for brightness on ice and costumes,

HFR for figure motion


• But, 13/11/2015 in France … experimentation shortened, only HDR tested

• 2 different cameras, one at a time - GrassValley LDX - Sony HDC4300

• 4K zooms: Fujinon 80x (UA80X9BE)

13-14 November 2015

Bordeaux, France

1/ Live sport in HDR


• 1st test (LDX) => a single camera to generate two streams: one HDR and one SDR

• 2nd test => an HDR-PQ camera (Sony 4300) and a SDR camera on a rig (Sony 2400)

• Remote control from production truck

• HDR and SDR comparisons



Production truck:

simulation of what will be next, when…

…here!

An extremely valuable experimentation, very own production space for HDR camera remote control



Many lessons learned on where difficulties are: how to control SDR and

HDR independently, yet in a single production?

2/ Bastille Opera live HDR production A single production to serve both HDR and non HDR: use of HLG technology


15 December 2015

Bastille Opera,

Paris France

2/ Bastille Opera live HDR production

www.4ever-2.com 42

HDR monitoring

709 monitoring

709 color gamut

Quad 3G SDI 4K HLG

Quad 3G SDI 4K HLG

downsizing

HD 709

vision engineer focus in SDR, then control HDR result

potential 709 graphics mapped to HLG with LUT

for instance towards HEVC encoder with

HLG signaling

for instance towards H264 encoder


709 monitoring OBvan HD signal

Sony 4300 (HLG prototype version) zoom Canon 90x (J90x9B)

Our HLG workflow, generating both

4K-HDR and HD-SDR

for comparison to broadcasted commercial

HDTV signal



Comparison between HD and UHD + HDR


A big success for invited producers and directors of photography:

loved both the SDR quality and the HDR potential



Despite tough content parameters…


Ultra HD phase 2

focus on HFR


HFR vs. TV set « sport mode »


High Frame Rate

50 frames / s transmission

100 frames / s transmission

Display interpolation

("sport mode")

Why doesn’t interpolation work well? • Frame interpolation (refreshment) does not always work

• Refreshment invents content => artefacts will happen: object is doubled, blurry, disappears, …


Refreshment as displayed on good consumer TV sets

(HD 1080p50, HEVC 7Mbps)

- Collaborative work with EBU, BBC and IRT (BTF HFR)

- Evaluate the added value of 100Hz in comparison with 50Hz in terms of perceived

video quality

- Uncompressed contents

- Compressed contents

- Using HEVC at 3 Mbps (BBC contribution)

- MCFI professional solution

- Using Alchemist OD (IRT contribution)

CONTEXT AND TEST OBJECTIVE

- SAMVIQ (ITU-R BT. 1788)

- Global notation for short duration clips

- Continuous quality scale (0-100) using quality items

- Bad, Poor, Fair, Good and Excellent

- Use of explicit and/or hidden references

- Observers

- Non-expert viewers

- Normal screening

- Rejection criteria used for results analysis

SUBJECTIVE TEST METHOD

VIEWING ENVIRONMENT

- Based on Recommendation ITU-R BT. 500

- Background luminance vs display peak luminance

- Viewing distance

- Room colors

TEST ORGANIZATION

- Viewing environment

- Viewing distance: 3H (2m)

- Background: 10% of the display peak luminance

- Test setup

- Subjective quality assessment software (Orange Labs tool)

- PC-based player: HP Z820, Matrox DSX LE4

- 55-inch HFR display (Mikrom): 4 x 3G-SDI (HD, 200/240p)

- 31 observers

- Non-experts

- Normal screening

TEST MATERIAL (1)

- 5 contents (sources)

- HD format (1920x1080p200, 16 seconds)

- Different motion features (camera motion, etc.)

BBC4

EBU

BBC9

BBC3

4EVER

TEST MATERIAL (2)

- 6 test conditions: 3 frame rates, 2 shutter values

- Test 1: uncompressed contents

- Test 2: compressed contents at 3 Mbps (HEVC)

200Hz 100%

Averaging 100Hz 100%

Averaging 50Hz 100%

Down sampling

50Hz 50%

MCFI 50 to 100Hz From 50Hz(50%)

MCFI 50 to 100Hz From 50Hz(100%)

Frame rate Shutter

RESULTS: UNCOMPRESSED CONTENTS


Frame rate : Shutter :

RESULTS: UNCOMPRESSED CONTENTS






RESULTS: COMPRESSED CONTENTS (3 MBPS)



MAIN CONCLUSIONS

- 100Hz native contents provide much better perceived video quality than 50Hz native ones

- The performance of Interpolation (MCFI) depends on the content’s motion features

- In the worst cases, the perceived video quality is lower than 50Hz native ones (visual

artefacts)

- In the best cases, the perceived video quality can reach the 100Hz native ones

- Best performances at 50% shutter vs 100%

- In average, 50Hz interpolated at 100Hz cannot reach the perceived video quality of native

100Hz

- At the same bitrate, the perceived quality of a 100Hz source remains better than a 50Hz

source (interpolated or not).

live HFR + HDR workflow

www.4ever-2.com 61

HDR monitoring

709 monitoring

709 color gamut

8x 3G SDI 4K HLG HFR

8x 3G SDI 4K HLG HFR

downsizing

HD 709 HFR

709 graphics upsampled to 4K HFR

HEVC encoder with HLG signaling

HEVC encoder

HD 709

frame averaging

H264 encoder

4K 709

frame averaging

HEVC encoder

WCG can also be introduced with extra complexity

? how to sync successive frames


Compressor challenges


63 4EVER-2 : go for UHD-TV phase 2! www.4ever-2.com

Compressor challenges

• Metadata feeding • Static/dynamic metadata • No standard methods: IMF, Side XML, VANC, others… • Metadata generation in the encoder?

• Content preparation • Chroma Subsampling/downscaling • Pre-processing • Color space conversion

• Compression • HDR Signal properties => new video defects may appear • Chroma and luma errors • 10-bit banding and contouring


HDR adapted content processing

OETF is highly non-linear => Non-Linear algorithms have to be implemented

• Chroma sub-sampling • HEVC Main 10 encodes 4:2:0 chroma samples

• Source is usually RGB 4:4:4 =>Sub-sampling has to be performed prior to encoding

• Conventional approaches can not be used => need to take transfer function characteristics into account

Y components

U,V components

R,G,B components


Color Processing Pipeline


Halos and chroma shifts

• Problem caused by the steep EOTF curve at high luminance

• For instance: • An error of 16 in code value

(1.5% of the full scale)

• => a luminance error of 123 nits (10% of the full scale)


Small errors cause large defects • Strong mosquito noise and chroma errors around bright edges

• Caused by quantization error spreading in blocks

Small area of a HDR source picture Compressed result


Avoid error spreading

• Take advantage of HEVC coding tree

• Small TU on bright edges for visual improvement

PU

TU

64x64 8x8

CU


Banding artifacts

• Most annoying and frequent visual defect when compressing HDR content

• Appears in unexpected areas even at high bit-rate

Area exhibiting banding

Luminance map


Barten ramp vs 10/11-bit PQ

• Barten ramp gives an indication of minimum visible contrast step

• One code value change in 10-bit may be visible, not in 11-bit

0.1%

1%

10%

0.001 0.01 0.1 1 10 100 1000 10000

Min

imu

m C

on

tras

t St

ep

(%

)

Luminance (cd/m2)

Barten Ramp

10-bit ST-2084 PQ

11-bit ST-2084 PQ


Contrast visibility

• All common 10-bit EOTF perform about the same

• One code value change in 10-bit may be visible with all EOTF

0.1%

1%

10%

0.01 0.1 1 10 100 1000 10000

Min

imu

mC

on

tras

t St

ep

(%

)

Luminance (cd/m2)

Barten Ramp

10-bit ST-2084 PQ

10-bit ARIB-B27 1200nits

10-bit BT.709 200nits


On noise encoding

• Avoiding banding artifacts is performed by adding dithering noise on the source

• But HEVC, H.264 and MPEG-2 are not efficient on noise

• The video codec tends to remove dithering noise leading to banding


How the encoder can help?

• Detect areas prone to banding an improve PSNR as much as possible

• Add strong in-loop dithering noise prior to encode in relevant areas

• Use Film Grain technology (generate noise on the receiver side) when available

• Or increase contrast and add a stronger dithering noise un post-production…but…

ST-2084 BT.709


Bitrate impacts

• PQ + metadata solution • HDR only

• HDR10 + metadata : very few bytes on GOP or scene basis

• Backward compatible • SDR + metadata => SDR base layer is encoded with increased bitrate of around 5%

• HLG solution • No bitrate overhead => further experiments

Dolby Vision Solution • Backward compatible

• Base Layer (either SDR or HDR) + Enhancement Layer => EL bitrate is ¼ of the base layer bitrate

Realisation of the first UHD-TV phase 2 TV clip

Using all UHD-TV phase 2 technologies

(4K, HFR, HDR, WCG) plus NextGen Audio


First fiction in UHD-TV phase 2 + 3D audio


4-7 November 2015

Paris, France

« 4EVER short »,

« Une danse pour la vie »

Quote from the author

« All the technical tools to define tomorrow’s TV have

a common goal: researching viewer immersion. This

short story narrative goes the same way, immerging

the audience into emotion »

Fiction in 4K, HDR, HFR, WCG and 3D audio


Bright lights in motion at night…

Motion inside a structure


Ultra High Technology to serve artistic intention, taking into account the power of the story


All about lights and contrast


Director of photography

and HDR experts team

Watch the making-of http://www.dailymotion.com/video/x3iw04w_4evershort_tv

http://www.dailymotion.com/video/x3iw04w_4evershort_tv






Conclusions and perspectives


HDR: high expectations… still some issues • No bitrate defined yet

– New nature of the video signal impacts encoder performance

• Current HDR TV sets are first generation

– Between 500 and 1000 cd/m² in 2015 (target = 1500 cd/m²)


• No standards yet, too many options

– Transfer functions (EOTF) => Dolby PQ, BBC/NHK HLG

– Format: 1 or 2 layers? Metadata or not? => Technicolor, Dolby, Philips

– Encoding: HEVC Main 10 or future MPEG technology

But live production can be operational pretty soon!

HFR: nearly ready, yet some issues • is 8xSDI manageable?

• monitoring in 50p and mix in 100p?

• sync issues – how to sync 2x 50 Hz SDI feeds?

• 100Hz clock?

• 50 Hz clock? If two feeds have a 50hz clock, which one is first? Can synch be based on odd/even frames?

– how to apply DVE to SDI feeds with same timestamps

• ie: how to fade two pictures at the same time but with different fading parameters?

• is it possible to add a delay of 10 ms for one picture effect?

• instant replay / slow motion in 4K 100 ?

– capture in 4K 300fps???

– interpolation?

• HD HFR production is probably a better alternative….


Technology impact on perceived quality

• Video subjective tests target in 2016 – HDR

• Comparison of solutions in terms of perceived video quality

• Impact of compression on HDR perceived video quality

– HFR • Impact of HFR on 4K resolution in terms of perceived video quality

• but displays?

– HFR + HDR • Impact of HFR + HDR combination in terms of perceived video quality

• NextGen Audio with UHD-Phase 2: tests end 2016/2017 www.4ever-2.com 84 4EVER-2 : go for UHD-TV phase 2!

Towards live HDR - WCG - HFR - 4K • Continue independent evaluations of

– Technology (visual assessments)

– Equipment : characterization of displays or cameras

– End-to-end workflow

• Promote HFR: a major added value for the first to jump in, a great way to differentiate

• Shoot sequences ourselves: complete parameter control and rights – Feb/Mar16: tbd – second HDR test – distribution trial

• Visible events – Apr16: HD/4K/HDR live production and distribution

– Jun/Jul16: Sports - HD/4K HDR/HD HFR live production and distribution test


Towards live HDR - HFR - 4K • Disseminate results in standardization committees

and conferences – DVB, ITU, MPEG, SMPTE

– For information to be where and when people make decisions, worldwide

– Selected for NAB2016 Futures Parks;

– IBC2016 FutureZone?

• Collaborations – display/camera manufacturers and everyone welcome!


Merci ! Thank you!

www.4ever-2.com

maryline.clare @orange.com

[email protected]

http://www.4ever-2.com/



Appendices


HDR and WCG workflows

for TV production and distribution


Prepare for a live UHD-HDR production

• Which camera and attached processors?

• Which HDR-SDR workflow?

• Which methodology for vision engineers?

• Which additional cost compared to HD, compared to UHD phase 1?

• How convince producers, and their photographers?


Backward compatibility in TV production

• The goal is to produce HD 709 + Ultra HD Phase 1 709 or 2020 and add HDR in the same workflow

– Adding HFR is also a must have, especially for sports!

• With few extra costs !

– no additional cameras

– using current technology (SDI 10 bits …)

– with few extra charge for production teams

• because TV distribution will remain mostly HD 709 at least for a number of years!


?

PQ/709 OETF + WCG/709 workflow

www.4ever-2.com 92

2020/P3 gamut 4K

HDR OETF

709 gamut HD or 4K 709 OETF

3DLut WCG 2020/P3 to 709

Quad 3G SDI 4K PQ WCG

Quad 3G SDI 4K 709 WCG

Quad 3G SDI 4K PQ WCG

Quad 3G SDI 4K 709 WCG

3DLut downsizing

HD 709

common settings ? 709 specific ? PQ specific ?

709 graphics mapped in WCG with LUT, 4K or

upsampled

Quad 3G SDI 4K 709 3DLut

HDR 10 encoder

HEVC encoder

H264 encoder

HEVC encoder

+ « fast track » Backward Compatible encoder?

mastering information


?

HLG OETF + 709 workflow

www.4ever-2.com 93

HDR monitoring

709 monitoring

709 color gamut

Quad 3G SDI 4K HLG

Quad 3G SDI 4K HLG

downsizing

HD 709

common settings ? SDR vs HDR tradeoff? 709 graphics

mapped to HLG with LUT


H264 encoder


?

HLG OETF + WCG workflow

www.4ever-2.com 94

HDR monitoring

709 monitoring

WCG color gamut

Quad 3G SDI 4K HLG WCG

Quad 3G SDI 4K HLG

downsizing

HD 709

common settings ? SDR vs HDR tradeoff? 709 graphics

mapped to HLG WCG using LUT


H264 encoder 3DLut

WCG to 709

3DLut WCG to 709

static color remapping metadata


live HDR workflow issues Camera Paint menu operations

• PQ vs 709

– common parameters: iris, color temp, details, noise, ..?

– separate parameters: gamma/knee, max lum, blacks ? others?

• HLG

– how to make a tradeoff between SDR efficiency and HDR efficiency? using knee point, max luminance? others?

• in both cases, some colorimetry mismatch should also be addressed, mainly for skin tones

• and of course camera sensor dynamic is essential! www.4ever-2.com 95 4EVER-2 : go for UHD-TV phase 2!