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Stephan VinkeProduct Manager

Gefen Europe GmbH

Definition of HDMI

The Interface, its mechanics and its properties

The Evolution of HDMI

HDMI 2.0 – a new step in Technology

What are the challenges with Extension, Switching and Splitting?

Training Agenda

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Definition of HDMI• Standardized Interface for digital, uncompressed transmission of audio-, video- and control data

• Introduced 2003 from the consumer electronics industry

• Goal was to replace and unify the different analogue Audio/Video formats with a future-proof All-in-one Interface.

• Video Resolutions from SD, ED, HD up to UHD-1 (4k UltraHD, 3860x2160 Pixel)

• Component (YCbCr) and RGB color Models and color spaces

• Audio/Video is transported uncompressed, serially and pixel orientated

• Audio is embedded into the Video data-stream (no separate wires!), all common digital consumer Audio Formats are supported

• HDMI Includes a bi-directional auxiliary data channel (DDC) for communication between source and Display (Plug & Play, EDID, HDCP), additional Metadata from Source to sink.

• Separate control channel for the control of multimedia devices (CEC)

• During the evolution of HDMI additional features where added

The HDMI Interface

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The Mechanics of HDMI

• The TMDS Interface is the „work-horse“ in the HDMI connection. It carries the AV data

• CEC stands for „consumer electronics control“. It‘s a control bus based on the earlierdeveloped (SCART) AV-Link standard. Allows exchange of function controldatabetween HDMi connected AV products

• DDC stands for „Display Data Channel“ – a standard created by VESA and adoptedby CEA(HDMI) for enablig „Plug & Play“ between Source and Display, as well forexchanging status data for „HDCP“.

• „Hot-Plug-Detect“ and „+5V“ are basic electrical signals for allowing a source todetect if a display has been connected

HDMI Interface explained - TMDS• TMDS stands for „Transition Minimized – Differential Signalling“• TMDS is the standard used first by DVI (1999) and later on by HDMI (2003) to carry

the load of Video (and Audio) data.• TMDS is a standard developed by „Silicon Image“ as a short range (<10m) high

Bandwidth Transmission Interface.• One TMDS Link has 4 twisted pair conductors• 3 data channels carrying the Pixel data, a 4th channels carries the clock signal.• Transport is pixel for pixel – Clock-channel = Pixel clock = 1 cycle per Pixel• Basic specification was max. 165 Mio. Pixel per second (=165MHz), actual Pixel

clock is up to 340MHz, HDMI2.0 will go up to 4x150MHz (600MSc)• The 3 data channels carry either R G B (DVI+HDMI) or Y Cb Cr (HDMI only) values• TMDS is no transport protocol, but a physical transport mechanism• TMDS has no adressing of the data packets, no error correction mechanism.

Transport is fully transparent and uncompressed.

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The digital picture representation with DVI and HDMI

„Quantification“i. e. 256 stages per elementary color.-> „color depth“

256 = 28 = 8 Bit/Subpixel24 Bit/Pixel

(DVI/HDMI1.2)

„Subpixel“

(Red-Green-Blue)DigitalProcessing

0

255 Black = 0, 0, 0

White = 255, 255,255

Grey= 128, 128, 128

Yellow = 255, 255, 0

Magenta = 255, 0, 255

Cyan = 0, 255, 255

ExamplesRGB color value

(RGB – Color scheme)

R=171

G=187

B=115

R=84

G=112

B=115

R=226

G=103

B=171

For HDMI „Deep color“ (10-12-16bit) additional bytes are created and transported(-> higher TMDS clock needed)

Transition Minimizing („TM“) – 8b/10b encoding(reduces switching noise for less RFI/EMI)

DC Balancing(reduces capacitance effects, improves steepnes of Signal flanges)

© Silicon Image

encoding bits are left out to simplify the example !

Byte inverted to reduce charging,signaling bit added

Data stream charges upcable capacitance

DC-balanced data stream

GPU output TM Encoder output

TMEncoder

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Differential Signaling („DS“)

Wanted Signals add up (+6dB), noise (Common mode) is subtracted

© Wikipedia.com

Audio via HDMI

DVI Frame Structure HDMI Frame Structure

Vertical blanking intervalVertical blanking interval

Vertical blanking interval Vertical blanking interval

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Total Horizontal

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Total Horizontal

HDMI has no extra Audio wires, but carries Audio and Metadata in the Videoframe!

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HDMI Interface explained - CEC

The Consumer Electronics Control (CEC) channel is u sed for sending command and control data between connected HDMI devices .

• Allows a user to control multiple CEC-enabled devices with one remote.• An example of CEC is ‘one touch play’.• CEC is a one-wire bus and has first been implemented in SCART as “AV-Link”• Many manufacturers have proprietary trade names for the CEC. Cross brand compatibility didn’t historically

exist but this is now improving.

Anynet+ - Samsung

Aquos Link - Sharp

BRAVIA Synch - Sony

HDMI-CEC - Hitachi

Regza Link - Toshiba

Simplink - LG

VIERA Link - Panasonic

EasyLink - Philips

HDMI Interface explained - DDCThe “Information Pipeline”

Display Data Channel

DDC is a VESA standard for a bi-directional communication interface for the transmission of information between a monitor and a graphic card/source . The data transmission is carried out by an I2C-connection via independent conductors and pins within the DVI and HDMI cable.

By using the DDC the display is able to inform the source about its properties such as resolution, display size, color d epth , color space, audio formats etc. (EDID). The source automatically provides the monitor a suitable signal (Plug & Play). The transmission of the EDID is a one-time, one- way communication process once the source and display is connected (Hot-Plug).

The Content-Protection procedure “HDCP” is using the DDC for authentication and the continuous communication between source and display and, if applicable, a “Repeater”.

This is a two way communication process.

Basically, DDC already exist since the introduction of the VESA standard SVGA (800x600) via VGA.

DisplayPort extends the DDC standard in order to transmit also larger data volume (i.e. audio backchannel, USB, webcam, etc.).

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HDMI Interface explained - Hot Plug Detect

• Hot Plug Detect – A pin on the DVI and HDMI connector that allows the source device to sense when a display device has been connected to it and its EDID is readable.

• A HPD is carried out by the Display feeding the +5VDC, provided by the source, back to it via the HPD wire.

• HPD is the first step in source device recognizing a sink has been connected. The sink can toggle the hot plug detect signal to reset the HDMI connection.

• HPD is also used by repeaters to request HDCP authentication process from a source device

Hot Plug Detect

Plug & Play, EDID & HDCP

Small words, BIG meaning!

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Plug & Play

„Plug & Play“ is a slogan that has been introduced in the Computer relatedtechnology world during the 1990ies.

It stands also for a Technology that has been standardized by the „Video Electronics Standards Association“ (VESA) for the automatic recognition ofDisplays from a Computer graphics adapter to adjust automaticallyResolution, Framerate, Color and other parameters for optimum Video representation.

The Technology has been adopted as well for HDMI

E D I DThe “Passport” of a Display

Extended Display Information Data

• A Data structure provided by a display (Monitor, TV, AV-Receiver or similar device) to describe its capabilities to a source.

• EDID has been developed by the VESA to enable Plug & Play.

• It contains information such as the Manufacturer name, production date, display size, display resolution, display refresh rate, color model, etc.

• The transmission of this data is carried out by the Display Data Channel (DDC).

• The EDID-Data structure is stored in the display integrated serial EEPROM and can be read via I²C (Even though the device isn‘t turned on, since the

EEPROM is powered by the computer and not by the power supply of the monitor).

• EDID is implemented in analog SVGA as well as in digital standards DVI, HDMI and DisplayPort.

• The EDID-Data structure is depending on the device 128 or 256 byte (CEA extension structure for HDMI) and consists of defined arrays and check sum in

order to transmit as much information as possible.

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DVI/HDMI Plug & PlayFeeding voltage 5V

Hotplug detect (HPD, high)

Display Data Channel (I2C-Bus)

01010011 11001100 10101100 00110011 01110001 00001111

Transmission of the EDID from monitor to the source

TMDS Lanes

Digital Picture/Audio transmission

„Source“ „Display“

EDID – What can go wrong?

� HDMI source never reads EDID, does not finish reading EDID, or does not read it properly.

� HDMI Extender/Repater alters the downstream EDID and/or changes formats.

� HDMI source cannot read EDID and doesn’t output (at least) 640x480 when EDID is unreadable.

� HDMI repeater is unable to merge a large number of EDID video timing descriptors (SVDs) from multiple downstream EDIDs.

� HDMI repeater forwards the downstream sink’s EDID capabilities properly to the source.

� Sink declares a color mode of YCbCr (“color difference”) in its EDID, but doesn’t support both types of sampling modes (4:4:4

and 4:2:2).

� Capacitance of the HDMI cable (DDC bus) too high (>700pF) – Data transfer is corrupted due to signal distortion

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HDCP defined

High-Bandwidth-Digital-Content-Protection (HDCP):

• It is a Content protection system , also used as a type of DRM (Digital Right Management)• It is not a copy protection !• Has been developed in 2003 by Intel in order to protect digital Audio- and Video signals transmitted via DVI and HDMI . DisplayPort is HDCP compatible.

• Has been requested and forwarded by the Entertainment Indust ry . The „Digital Content Protection LLC“ is responsible for the administration and certification process.

• A digital HDTV source (BlueRay Player, Computer, digital Set-top box) is not allowed to send any Audio- or Video signal to a Receiver (Display, Projector, AV-receiver) which isn‘t HDCP conform.

• I.e.: If a HDCP source is connected to a non HDCP compliant HDTV display, a white picture noise appears or even no signal at all. • Analog (HDTV) outputs are also affected and can be shut off (ICT, Image constraint token).

• HDCP reglements the max. number of displays per sour ce (PayTV).

The HDCP Technology is still causing „handshake problems“, especially in combination with older HD displays or in complex setups.

- HDCP requires a two-way communication between sender und receiver via the DDC.- A authentificaton process avoids, that a unlicensed device receives a signal.- The „Key Revocation“ process avoids, that cloned or compromised devices still receiving any data.- Every HDCP capable device has its own unique key set (>670.000.000.000 different unique KSV)

HDCP Devices

HDCP sender(TX)

„Device A“

HDCP receiver (RX)„Device B“

TMDS

DDC

SecretKeys

40x56bit

KSV40bit

Revoc.Liste

HDCPEngine

HDCPEngine

Audio/Videoencrypted

Authentication & control

DVI/HDMIconnection

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HDCP Hardware

HDCP sender (TX)

„Device A“

HDCP receiver(RX)

„Device B“

TMDS

DDC

Audio

Video

Audio

Video

Control

Data

Secret Keys40x56bit

KSV40bit

Revoc.List

HDCPEngine

Secret Keys40x56bit

KSV40bit

Revoc.List

HDCPEngine

Audio/Videoencrypted

Authentication & control

DVI/HDMIconnection

HDCP Handshake

TMDS Lanes

HPD, EDID

Display Data Channel

A/Vencrypted

HDCP sender (TX)„Device A“

HDCP receiver (RX)„Device B“

Calculating Pseudo-randomnumber AN, sending AN and AKSV

AN & AKSVControls AKSV, saves AN

BKSV

Ready!

Controls BKSV, calculates sessionKey KS

AKSV ok! -> sends BKSV, & Calculates session Key KS

Calculates check sum R0‘, sends R0‘ („Ready“)

Calculates check sum R0 compares R0 = R0‘ ?

Encryped AV datawith calculated key

Decrypted AV datawith calculated key

Calculate und send Ri‘Calculates Ri,

Ri‘ = Ri? & t<1ms ->ok!(link verification)

100m

s

„Link verification“ all

2s

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HDMI1.0

HDMI1.1

HDMI1.2

HDMI1.3

HDMI1.4

The Evolution of HDMI

HDMI2.0

• HDMI Versions are not a quality attribute!

• HDMI Versions stand only for a list of Options , test procedures and protocols

• A product listed as having a HDMI version does not necessarrily mean that it will have all of the featuresthat are listed for that version!

• HDMI Version numbers therefore are often misleading

• It is mandatory to inform about the Options supported by an HDMI compliant product

• HDMI products of different Versions are compatible – when installed in the right way!

• with the release of the version 1.4, the HDMI Licensing LLC group requires that any reference to version numbers be removed from all advertising for cable products.

• Starting on January 1, 2012 Non-cable HDMI products will no longer be allowed to reference the HDMI number and will be required to state which features of the HDMI specification the product supports

The HDMI version mess

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HDMI 1.3 overview• Higher data rate/speed: HDMI increases its single-link bandwidth up to 340MHz (10,2GBit/s) to support the demands

of future HD display device, such as higher resolutions, deep color and high frame rates.

• Deep Color: HDMI 1.3 supports 10-bit, 12-bit and 16-bit (RGB or YCbCr) color depths per pixel, up from the 8-bit depths in previous versions of the HDMI specification.

• Broader color space: HDMI 1.3 adds support for “x.v.Color™” (IEC 61966-2-4 xvYCC Color standard), which

removes current color space limitations and enables the display of any color viewable by the human eye.

• New Mini connector: The HDMI standard will be extended by a new and smaller connector in order to integrate also

the smallest device to the HDTV chain (HDMI Type C)

• Lip Sync: HDMI 1.3 incorporates automatic audio synching capabilities that allow devices to perform synchronization automatically with total accuracy.

• New high resolution audio formats: HDMI 1.3 adds additional support for new lossless compressed multichannel

audio formats: Dolby TrueHD and DTS-HD Master Audio™.

• HDMI Ethernet Channel (HEC) – Adds high-speed networking (100Mbit/s) to an HDMI link, allowing IP-connectivity without a separate Ethernet cable. Needs a specific HDMI cable.

• Audio Return Channel (ARC) – Allows an HDMI-connected TV with a built-in tuner to send audio data "upstream" to a surround audio system, eliminating the need for a separate audio cable

• 3D – Defines input/output protocols for major 3D video formats

• 4K Support – Enables video resolutions up to 4096x2160p24 or 3840x2160p30

• Additional Color Spaces – Adds support for additional color spaces used in digital photography and computer graphics (sYCC601, AdobeRGB, AdobeYCC601)

• Automatic Content Enhancement (ACE) - Real-time signaling of content types between display and source devices, enabling a TV to optimize picture settings based on content type

• HDMI Micro Connector – A new, smaller connector for phones and other portable devices, supporting video resolutions up to 1080p

• Automotive Connection System – New cables and connectors for automotive video systems, designed to meet the demands of the motoring environment while delivering true HD quality

• High Speed HDMI 1.3 cables can support all HDMI 1.4 & HDMI2.0 features except for the HDMI Ethernet Channel (HEC)

HDMI 1.4 overview

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• Bandwidth up to 18Gbit/s

• TMDS clock rates between 300MHz and 4x150MHz (600MSc) with scrambling (for EMI/RFI reduction ) and TMDS Error

correction (no new cables needed for HDMI2.0!)

• 4K@50/60, (2160p, UltraHD 4k (3840x2160)

• YCbCr 4:2:0 Pixel Encoding for 2160p formats (saves 50% Bandwidth compared to 8bit, 4:4:4)

• Up to 32 audio channels for a multi-dimensional immersive audio experience

• Up to 1536kHz audio sample frequency for the highest audio fidelity

• Simultaneous delivery of dual video streams to multiple users on the same screen

• Simultaneous delivery of multi-stream audio to multiple users (up to 4)

• Support for the wide angle theatrical 21:9 video aspect ratio

• Dynamic Auto Lipsync

• CEC extensions (CEC2.0)

• HDCP 2.2

HDMI 2.0 overview

New Features

• 4K 50/60Hz 4:2:0 Color coding ( 300MHz bandwidth ). First products out Q1 2014� Firmware upgrades needed for Gefen 4k 30Hz products.

• 4k 50/60Hz 4:4:4 Color coding ( 4x150MHz (600MSc) bandwidth ). First products out Q1 2014 ( Panasonic only ), others to follow Q4 2014 or 2015. � New Hardware needed

• HDMI 2.0 adds support for HDCP 2.2 copy protection standard, it is a replacement not upgrade of HDCP 1.x. � New Hardware needed for reproducing HDCP 2.2 protected content

• Dual display capability, dual view using glasses and laptop external display cascading. � Unclear deployment schedule

• Large amount of audio channels supported up to 32ch� Implementations 2015+

HDMI 2.0 Highlights & Challenges

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• New copy protection standard by DCP to replace HDCP 1.x.

• Hollywood pushes all 4k consumer content to require HDCP 2.2

• Not firmware upgradeable, requires new chipsets.

• Some Gefen products support already this, list will be released asap( pending testing )

• Backwards compatible, if source content doesn’t require HDCP2.2.

HDCP 2.2 Information

New Features (Gefen new Products ~Q4 2014)

• Native support for USB, at start mouse, keyboard and storage, later also audio devices and cameras.

• Additional audio forward and return channel.

• Support for multi stream link( several video streams on one cable ).

• Same bandwidth as current HDBaseT products.

• Slightly better performance at high resolutions and substantially better EMI resistance.

HDBaseT 2.0 Highlights

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