4k Theoretical Discussion What content is 4k? Mastered in 4k - - PowerPoint PPT Presentation

4k Theoretical Discussion

What content is 4k? “Mastered in 4k” Blu-ray Digital Cinema Cameras Differentiating 4k from HD

Defining 4k

Sony F65 – shoot in 4k Sony F35 – shoot in HD Shoot on film Film Scanner

2k Files

Scan in 2k

4k Files

Scan in 4k

Film in Archive

Finish in 4k Finish in 2k Downscal e to 2k 4k Digital Cinema 2k Digital Cinema Master in HD Blu-ray Master in HD Blu-ray Finish in 2k 2k Digital Cinema “Mastered in 4k”

Digital Cinema Cameras

HD and 2k Cameras

4k Cameras

Pixel count: G=4096, B=2048, R=2048 Pixel count: G=2560, B=1280, R=1280

4k or not?

Sony F55

23.6mm x 13.3mm Pixel count: G=2240, B=1120, R=1120 Unconfirmed pixel count: G=2048, B=1024, R=1024

Making 4k better than HD

Differentiating 4k from HD

Higher resolution alone is not enough, 4k has to be differentiated from HD in four ways:

• Higher resolution
• Greater bit depth
• 10-12 bits vs. 8 bits
• Higher dynamic range
• Better shadows and highlights
• Wider color gamut
• Display more colors

TV Best viewing distance Sofa 8’ from screen 24” Standard Def 8’ Ideal 65” High Def 8’ Ideal 85” 4k 5’ Could sit closer 130” 4k 8’ Ideal

xvYCC color for 4k and HD

xvYCC Color

• Background:

– xvYCC is a color space that supports a gamut larger than the color space of HDTV which is called Rec 709 – xvYCC was proposed by Sony and published in January 2006 as an IEC standard – xvYCC makes use of code values that are not defined in Rec 709 – The Bravia XBR8 supported xvYCC but the feature was removed in later models

• Blu-ray discs mastered in xvYCC will be watched by many consumers on TVs that do not support xvYCC

– Blu-ray players will not convert from xvYCC to Rec 709 – The way that a Rec 709 TV displays xvYCC code values undefined in Rec 709 is also not defined – No way of knowing what other manufacturer’s sets will do

• Care has to be taken when mastering xvYCC content to ensure it looks good when displayed on a Rec 709

TV

Mastering xvYCC

P3 Transform & Color Correction xvYCC Master BD Master Transform Rec 709 Master QC on xvYCC display QC on Rec 709 display iTunes Master QC on Rec 709 display

Notes:

• P3 is the color space for digital

cinema and all theatrical content is mastered in P3

• Rec 709 is the standard color

space for HDTV

• The xvYCC color space is larger

than Rec 709 but smaller than P3

Tactical Discussion: Creating more 4k content

New movies and TV Restorations

Creating New 4k Content

Shoot in 4k

• Obstacles:

– Arri Alexa 2k camera is very popular with film makers and TV producers – Significantly more data to unload from card, store and transfer – High cost of memory cards for Sony F65 4k camera – F65 is not a finished product – Red Epic does not look as good as Alexa or F65

Finish in 4k

• Obstacles:

– Most post houses cannot display 4k – Not all finishing systems can handle 4k – HD TV workflows are established and time critical – finishing in 4k will be incremental

• Effects in 4k

– Rendering in 4k will take 4x as long as rendering in 2k – Some effects can take 100 hours per frame to render just in 2k – Can render in 2k, and up scale to 4k – Can render in more than 2k but less than 4k and up scale to 4k

4k Restorations

• Can restore anything shot on 35mm or 65/70mm film in 4k

– Decreasing number of titles shot on film in last 10 years

• All SPE restorations* were scanned in 4k but many were finished in 2k

– Dirt and scratch fixes done in 2k have to be repeated in 4k

• Some studios have restored a number of titles in 4k

– Many 4k restorations done at Colorworks or Warner Bros’ MPI facility – Not a large number of titles

• Further review needed in order to determine which library titles are suitable

for 4k restoration

*Not all re-mastering is a restoration

Content protection for 4k

Studios’ Viewpoint HDMI Link DRM

Starting Point

• 4k in the home is being driven by CE.
• Studios show little interest in releasing 4k to the home.
• Studios can and will likely wait for an enhanced content protection

system before releasing 4k premium content.

• Enhanced content protection debate has already started in Ultraviolet

– Studios want enhanced content protection for HD – Implementers have proposed it for 4k, early window and 3D

• Blu-ray was different. Both CE and studios wanted HD discs therefore

compromises were made.

4/7/15 Sony Pictures Confidential 17

Content Protection Overview

DRM

• Protecting the content from the service provider all

the way to the video buffers

• Ultraviolet has 5 DRMs for improved interoperability
• Today’s DRMs rely on renewable components to

respond to security breaches

– E.g. Adobe Flash player updates

• Most DRMs today are “hack one, hack all”

– When the DRM is compromised, all titles published to date are exposed

Link Protection – Last six feet

• HDCP over HDMI interface

– HDCP 1.x is compromised – HDCP 2.1 is much more secure – Sony 4k products only have HDCP 1.x

• DTCP-IP

– Link protection for DNLA – Not all Sony products with DNLA have DTCP-IP (that means there is no premium content over DNLA) – Some studios do not believe DTCP robustness requirements are good enough.

HDCP Link Protection

HDCP 1.4

• HDCP 1.0 published in 2003
• 56-bit proprietary encryption algorithm
• Key generation algorithm secrets were

reverse engineered so device keys can be generated by anyone

• HDCP has no response for that scenario

HDCP 2.1

• HDCP 2.0 published in 2008, HDCP 2.1 published

in 2011

• HDCP 2.1 has higher robustness requirements

that HDCP 1.4

• 128-bit AES standard encryption
• New security model, not vulnerable to same attack

as HDCP 1.4

Studios will require HDCP 2.1 for 4k content. Sony 4k TVs only support HDCP 1.4.

AACS – Blu-ray’s Content Protection

• Design started in 2002

– Sony, Panasonic, Toshiba, Intel, Microsoft, IBM, Disney, Warner Bros

• Different security models for CE and IT

– Unique device certificates for hardware BD players because CE did not want to have to download new firmware – Shared device certificates for software BD players because cannot securely incorporate unique device certificates in software players

• Response to a security breach is to revoke compromised device certificates
• High definition analog outputs were permitted

– Studios did not want analog outputs because analog outputs cannot be protected – CE needed to accommodate a legacy of several million HD TVs without digital inputs – Compromise was HD analog sunset in December 2010

• Fox disliked AACS so much they introduced BD+

AACS – Breach Management

• Breach response is to revoke compromised certificates so that they cannot be used to play AACS content
• When a device certificate compromised all Blu-ray discs mastered until that certificate is revoked can be ripped.

– This is “hack one, hack all”

• Revocation takes 3-6 months including due process for licensee

– Revocation only protects discs mastered after the certificate was revoked – If a software player certificate is revoked consumers will have to update software players in order to play new discs. – If a hardware player certificate is revoked the player is bricked (since CE did not want to support renewability)

• Makers of commercial ripping software obfuscate the certificates they are using making it very difficult to know which

certificate to revoke

– Some commercial ripping software is SaaS

• Revocation only works at all until someone figures out how to hack a hardware player

– When that happens AACS revokes the player certificate, pirate buys a new player, repeat

What do we learn from AACS?

AACS

• 1. Legacy HDTVs with only analog outputs

were accommodated only because all parties wanted HD discs.

• 2. “Hack one, hack all” has to be avoided.
• 3. Compromised certificates came from weak

software implementations

• 4. Revocation does not work: too slow, cannot

always tell which certificates to revoke, has an epic fail scenario.

What it means for 4k

1. Since studios aren’t in a hurry for 4k they are unlikely to accept lower security standards in “legacy” 4k products 2. Content protection needs to be per-title (or even per account) – no more hack one, hack all 3. Third party certification of security implementations 4. Continuous breach monitoring, rapid breach response, proactive breach response.

Enhanced Content Protection

• Select a security solution provider with a proven track record
• Software diversity per title and even per account
• Decode in Trusted Execution Environment
• Protected right up to the video buffer
• HDCP 2.1 required for output
• Device keys protected by a Hardware Root of Trust
• Require 3rd party verification of trusted DRM software

Breach Management

• Security provider monitors Internet (websites, chat rooms, IRC, etc) for indications
• f security breaches
• Security provider works with manufacturers to identify circumventions used by

attackers

• Countermeasures developed and deployed immediately a breach is detected
• Some new content may prevent playback on certain devices until player is up-to-

date

• “Tracing Traitors” mechanisms to track compromised implementations

Content Protection Recommendations

• SPE recommends engaging with an established security solutions

provider

– For example NDS, a Cisco company, has a long history in content

• security. While NDS does not have a current product that meets the

requirements, they have the component technologies.

• We can socialize the idea with the other studios
• Avoid the 2-3 years to create a new content protection system

– Longer if too many companies are involved

Content Delivery

SPE Point of View Proposal

Premium Content Broadcast Content Studios Broadcasters Consumers User Content Users Broadcast

(Over the air, cable, satellite, IPTV)

Download Physical media Streaming

Content Business/Delivery Models

• Business models

– Electronic Sell Through (EST). Examples are iTunes, Amazon, Ultraviolet – Video on Demand (VOD). Examples are iTunes, Amazon – Subscription. An example is Netflix – Ad Supported. An example is Crackle

• Delivery Models

– Download – Stream

• Physical media with EST (Ultraviolet or digital copy)

– Consumer purchases title on physical media – Physical media coupon (“Redemption Code”) allows to consumer to add to their online account – Consumer can play content

– Directly from physical media, or – From online retailer cloud service by streaming or download – Examples are Ultraviolet coupons with Blu-ray and DVDs

Recommended Content Delivery

• Physical media, download and streaming are just different ways to get the

content to the consumer

• Use the same file format for download and physical media

– Standardized file format such as the Ultraviolet Common File Format (CFF)

• Streaming with industry standard MPEG-DASH

– It uses a file format that is similar to CFF

• Content format not tied to physical media format

– In Blu-ray content format was driven by the disc format and capabilities of hardware devices of the time

Spencer Stephens

spencer_stephens@spe.sony.com