The free lunch: progressive-scan at the same bit rate? (or how I learned to love 1080p/60)

EBU TECHNICAL

The free lunch:

progressive-scan at the same bit rate?

(or how I learned to love 1080p/60)(or how I learned to love 1080p/60)

David Wood and Hans HoffmannEuropean Broadcasting Union

EBU TECHNICAL - your reference in media technology and innovation

Where’s the deep magic?

The compressed bit needed for 1080p/60 is the same or less than for 1080i/60.

Original scenes always exist in ‘whole pictures’

Interlacing is a form of compression (drop alternate lines with field offset).

Interlacing is a ‘systematic’ compression system (same whatever the contents of the scene).

Hybrid MC DCT is a ‘content adaptive’ compression.

Interlacing is the New England Patriots.

Hybrid MC DCT/Wavelet is the New York Giants.

You know who should win.


Where’s the deep magic?

An interlaced system combines TWO stages of compression: first interlacing, then hybrid MC DCT.

A progressive system just uses hybrid MC DCT for the total process.

The hybrid MC DCT (redundancy extraction) ‘replaces’ the interlacing.

We replace a ‘systematic system’ with a ‘content adaptive’ system.

The content adaptive system is ‘bound to win’.

The progressive system will always be equal to or better than an interlaced system on average.

Interlace needs half the bit rate of a progressive system only because it already half compressed.


That was yesterday....

Interlacing was a brilliant idea in the 1930s.

We used interlaced scanning because it was a simple way to reduce bit rate by 50% when we had no other ways.

We used interlaced scanning because it was a good match to the way a CRT works.

Which of the above apply now?


Idealised spectrum bounderies...for rapid look.

540

c/pw

100

200

300

400

500

360

c/sec25

1920x1080i with Kv=0.7, I=0.7

1280x720pwith Kv=0.7

540

c/ph

100

200

300

400

500

360

c/sec25


WHERE DOES 1080P/60 FIT TODAY?

Production, Contribution, distribution.


Playing the new ‘Chutes and Ladders’

1 2 3

4 5 6

7 8 9

LINEAR(audio-visual mat)

NON LINEAR(audio-visual mat)

MULTIMEDIA/SOCIAL(data, text, pictures, interact)

MEDIA - SERVICES

ME

DIA

- C

ON

TE

XT

SHARED(lean backward)

PERSONAL(lean forward)

MOBILE(on the move)

Media companiesneed to be active on all platforms:•Different services•Different networks•Different devices


Growth in quality of experience

1 2 3

4 5 6

7 8 9

LINEAR(audio-visual mat)

NON LINEAR(audio-visual mat)

MULTIMEDIA/SOCIAL(data, text, pictures, interact)

MEDIA - SERVICES

ME

DIA

- C

ON

TE

XT

SHARED(lean backward)

PERSONAL(lean forward)

MOBILE(on the move)

NEED FOR INCREASEDQUALITY

“Beyond HD”


The staircase to production quality heaven...

1990s 2004 ….2016….2011 …202x

DIGITALStandard TV625 –lines

DIGITALStandard TV625 –lines

Legacy HDTV1080i/25 & 720p50

S3Dtwo ½ HD images

Legacy HDTV1080i/25 & 720p50

S3Dtwo ½ HD images

Transitionanalogue to digital

TransitionSDTV to HDTV

HDMaster Format

1080p/50Progressive

S3DTwo normal

HDTV images

HDMaster Format

1080p/50Progressive

S3DTwo normal

HDTV images

Transitionto 1080p/50

(full HD) 4k UHDTVProgressive

Larger colour range.

3DTVTwo normal

HDTV images

4k UHDTVProgressive


3DTVTwo normal

HDTV images

4k(4x1080p)

8k Ultra HDTVProgressive

Higher Frame rates


3DTVMultiview

8k Ultra HDTVProgressive

Higher Frame rates


3DTVMultiview

8k (16 x 1080p)

Imm

ersi

ve Q

ualit

y


What happens to quality?


1080i/30 (interlaced)1920

1080

1.5 Gbit/s

Nominal staticresolution

1920x1080

60 frameprogressive

1080p/60 (progressive)1920

1080

3 Gbit/s


720

1.5 Gbit/s

1080p/60...


• Master format: easy to derive 720p/60 and 1080i/30• Higher image quality headroom• Multi-genre production• 3G-SDI enables 1080p/50 in production and 3D applications (two normal HD

signals)• Studio compression systems for 1080p/50 on the market

Why 1080p/60 production ?


EBU Tests on studio compression systems for 1080p/50 Conducted in a project between EBU and industry

Multigeneration testing


1080

3 G

bit

/s in

terf

ace

365 Mbit/sec 160.4 GByte/hour

AVID DNxHD4:2:2 10 bit

PanasonicAVC-Intra 2004:2:2 10 bit

454.6 Mbit/sec 199.77 GByte/hour

SONYHDCAM-SR

HDCAM-SR lite4:2:2 10 bit

734 Mbit/sec 322,5 GByte/hour

367 Mbit/sec 161.2 GByte/hour

Graphic Massimo Visca, RAI


Zeiss Master Prime Lens

Sony F35 Camera

Skilled team (NRK+ others)

Uncompressed storage YUV10 2 DVS systems with dual link

Sony reference display 23” LCD

Shooting test sequences in 1080p/50

State of the art equipment


Expert Viewing at IRT (1°- 3° March 2011)

Dolby 42” PRM-4200 Professional Reference Monitor (1920 x 1080 LCD monitor with LED backlighting).

Viewers from more than 10 EBU members


Snell Alchemist converter 1080p/50 to 1080i/251080p/50 to 720p/50

Full Quality HDTV Library


Different encoders provide different performance but, on average, the encoders demonstrated a performance which is nearly transparent to the original even up to the 7th generation.

The tested codecs (1080p/50, 1080i/25, 720p/50) meet the EBU requirements for image quality.

Different encoders provide different quality headroom.

Target applications today: high budget productions.

Conclusion:

High quality 1080p/50 production tools are available

Expert viewing - Results in a nutshell


The BPN reports

The Results


Step 2: 1080p50 in an End to End Chain

Demonstration at IBC 2011

Live chain including 1080p/50 camera, 2 hops--contribution codecs and distribution encoder, prototype set-top box

Simulations a 1080i/25 chain was set up using the same bit-rates

Image quality comparison on two Dolby reference Monitors


IBC 2011 experiment with live 1080p/50 chain

Live 1080p/50 from Frankfurt to Geneva to Amsterdam


Towards a single HD production master format:1080p/50

Live 1080p/50 from Frankfurt to Geneva to Amsterdam




Results of the experiment

A end to end 1080p/50 chain is feasible with today’s equipment

Same distribution bit rate as 1080i/25 with better image quality (main benefit is sharpness stays in motion)

Is mainstream production possible?– If manufacturers would reduce prices, yes

– But not all editing systems support 1080p/50 yet

In distribution?– Systems such as DVB support 1080p/50

– Many home display with HDMI 1.3 can show 1080p/50

– New set-top boxes/receivers with support of H.264 Level 4.1 would be required


HDTV today

1080i/25 (interlaced)1920

1080


720

Quality in the home– Larger size display make artefacts more visible

– Displays are all progressive – low cost up-converters for interlaced HD

– UHDTV displays set to appear in the home

– Alternative content (download, Games) better than broadcasts?

Consequently: need for better image delivery format ?


Is the difference big enough between 1080i/25 and 1080p/50?

Is the difference visible in the home?

On a small display (up to 42”) – likely not

With larger displays, or displays up converting to 4K UHDTV displays – very likely YES

In production to have a future proof master: YES


What about an intermediate chain….?

8k@p60Or4k@p60

4k@p50

4k@p50 with HEVC

X Mbps

4k Display

production chain

We would be curious in such an subjective comparission experiment:

1080@p50With H.26414 Mbps


Overall conclusion

• 1080p/60 may be the best production option for 720p/60 and 1080i/30 delivery

• Uses ‘3G’ production infrastructures

• Many broadcasters are wisely “1080p/50 ready”

• There is no 4K infrastructure available yet

• Still high prices, not yet ‘mainstream’

• Production bit-rates 200…400 Mbit/s

• Best master format for the next few years until 4K UHDTV is feasible

• In the home, 1080p60 may be an option for some services - many consumer displays and some receivers can handle 1080p60

• 1080p/50 in distribution could also help a 4k production and home environment.


Thank you for listening!

Further questions contact: [email protected] and [email protected]

Acknowledgements

EBU Codec group of SP HIPS many members and industry

Massimo Visca, RAI (also for some slides)

Jens Fischer (Master Student), IBC demo

Many others……..

Documents

The free lunch: progressive-scan at the same bit rate? (or how I learned to love 1080p/60)