DP and HDMI Protocol Fundamentals...The difference between YCbCr and RGB is that YCbCr represents color as brightness (Y) and two color difference signals (Cb and Cr), while RGB represents

DP and HDMI Protocol Fundamentals

Granite River Labs

Allen Chen([email protected])

Shanghai, July 11, 2017

Taipei July 13, 2017

Agenda

✓ Overview of HDMI

✓ Overview of DP

✓ Introduction to HDMI Protocol

✓ Introduction to DP Protocol

2

How do HDMI and DisplayPort Compare?Feature HDMI DisplayPort

Latest specification 1.4 and 2.0 (2.1 under development) 1.4

Latest CTS 1.4b and 2.0s 1.2b, V1.0 for Alt mode

Deep Color Yes, up to 48bits per pixel Yes, up to 48bits per pixel

Pixel Encoding RGB

YCbCr : 4/4/4, 4/2/2, 4/2/0

RGB

YCbCr : 4/4/4, 4/2/2, 4/2/0

Target applications

(both technologies appear in many applications)

Home theater PCs and mobile

Video Data Architecture Frame-based, RGB+clock Packetized, 8b/10b

encoded, embedded clock

Spread Spectrum Clocking Supported? No Yes

USB Type-C Alt Mode? Yes, for 1.4b Yes for all data rates

Dynamic Link Negotiation? No Yes(Aux Channel)

All data Link? No(one Clock Lane) Yes

Capability Identification Between Sink/Source Using EDID Using EDID

What’s NEW in HDMI 2.0

✓ Scrambling

✓ 4K@50/60Hz and HDR

✓ BT.2020

✓ Dual view

✓ Multi-Stream audio

✓ Up to 32 audio channels

✓ Audio sampling rate up to 1560kbps

✓ 21:9 aspect ratio

✓ Auto Lipsync correlation

What’s NEW in HDMI 2.1*(*spec announced in January 2017 but still under development)

✓ Supports a range of Higher Video Resolutions and faster refresh rates

including 8K60 and 4K120

✓ Dynamic HDR

✓ Increased bandwidth with a new 48G cable for uncompressed HDMI 2.1

feature support including 8K video with HDR

✓ eARC supports the most advanced audio format

✓ Game Mode VRR (variable refresh rate)

What’s NEW in DisplayPort 1.4

✓ High Bit Rate 3 (HBR3) – 8 Gbps

✓ Enables support of 4K at a 60Hz frame rate using only two lanes

✓ First DP standard to incorporate Display Stream Compression (DSC) technology

✓ Enables up to 3:1 compression ratio

✓ Facilitates High Dynamic Range (HDR) and 8K video across the USB-C connector

✓ Increased display resolutions including 8K@60Hz HDR deep color and 4K@120Hz

HDR deep color

✓ Forward Error Correction (FEC) - overlays the DSC 1.2 transport, addresses the

transport error resiliency needed for compressed video transport to external displays.

✓ Expanded audio transport – covers capabilities such as 32 audio channels, 1536kHz

sample rate, and inclusion of all known audio formats.

Introduction to HDMI Protocol

HDMI Link

8

HDMI Link Architecture

9

10 bits

encoded

pattern on

TMDS

Channel

1.4b

2.0b

Video Data Period

Data Island Period

Control Period

Operation Mode of TMDS Link between 1.4 and 2.01.4b 2.0b

Compared to 1.4b, 2.0 includes Scramble Bit and

Scrambler Synchronization Control Period

Operation Mode of TMDS Link

1.4b

2.0b

A control period is located between each data Island and video

data period.

-- preamble and Guard band

Video Data Period1.4b with TMDS Coding

Channel 0, 1 and 2 8b/10b

2.0 with TMDS Coding

Channel 0, 1 and 2 8b/10b

TMDS coding

8b/10b

Video data use TMDS coding 8b/10b

2.0 video data will be scrambled before coding.

Guard Band of Data Island Period1.4b with TERC4 Coding

Channel 0 depending upon HSYNC and VSYNC

2.0 with TERC4/TMDS Coding

Channel 0 depending upon HSYNC and VSYNC

Channel 1 and 2

TERC4 Coding

4b/10b

Channel 1 and 2

TMDS coding

8b/10bIsland data use TERC4/TMDS coding 4b/10b

2.0 Package data will be scrambled before coding.

Control Period

1.4b and Unscrambled portion of SSCP 2.0 Scrambled Control Period

ControlVector and IToggle

Control Period Coding

2b/10b

Control Period

Coding

TMDS Channel LN1 LN2

0 0b00 0b00

1 0b01 0b01

2 0b02 0b02

Closer Look at Operating Mode✓ A closer look at active video start

Data Island Pixels

(TERC4 Encoding)

Active Video

Pixels

(TMDS Encoding)

Video

Preamble

(8 Pixels)

Video Guard Band

Fixed 10 bit values

Control Period(> 4 Pixels)

Trailing Data Island Guard Band

Fixed 10 bit values

✓ A closer look at Data Island period

16

Closer Look at Operating Mode

Control Period

Data Island Pixels(TERC4 Encoding)

DI Preamble (8 Pixels)

Control Period(> 4 Pixels)

Leading Data Island Guard Band

Fixed 10 bit values

Trailing Data Island Guard Band

Fixed 10 bit values

Data Packet Construction

✓ All data within a Data Island is contained within 32 clock Packets

✓ Packets consist of a Packet Header, a Packet Body (consisting of four Subpackets), and associated error correction bits.

✓ Each 10 bit of Data 0, Data 1 and Data 2 are converted to 4 bits each

✓ Data 0 contains HSync, VSync and BCH4 Block data(Header Block)

✓ Data 1 and Data 2 provides BCH0 to BCH3 blocks

✓ Each Subpacket includes 56 bits of data and is protected by an additional 8 bits of BCH ECC parity bits

17

✓ Convert each Data0, Data1 and Data2 10 bit Data Guard Band to TERC4 encoding

18

0 1 2 .. … … … …2

9

3

0

3

1Data 0

0 1 2 .. … … … …2

9

3

0

3

1Data 1

0 1 2 .. … … … …2

9

3

0

3

1Data 2

Data Guard Band Data Guard BandData Island Pixels

10 Bit TERC4 Encoded Signals

0 1 2 .. … … … …2

9

3

0

3

1Data 0

0 1 2 .. … … … …2

9

3

0

3

1Data 1

0 1 2 .. … … … …2

9

3

0

3

1Data 2

Data Guard Band Data Guard Band

4 Bit TERC4 Decoded Signals

abcdefghig

ABCD

abcdefghig

ABCDEFGH

Data Island Explained

4 Bit TERC4 Descrambled Signals




2.0 : Data 1 and Data21.4b : Data 0, Data 1, Data22.0 : Data 0

✓ Convert each Data0, Data1 and Data2 10 bit packet date to TERC4 encoding

19

0 1 2 .. … … … …2

9

3

0

3

1Data 0

0 1 2 .. … … … …2

9

3

0

3

1Data 1

0 1 2 .. … … … …2

9

3

0

3

1Data 2

Data Guard Band Data Guard BandData Island Pixels


0 1 2 .. … … … …2

9

3

0

3

1Data 0

0 1 2 .. … … … …2

9

3

0

3

1Data 1

0 1 2 .. … … … …2

9

3

0

3

1Data 2

Data Guard Band Data Guard Band


abcdefghig

ABCD

abcdefghig

ABCD



✓ Assemble the data Packet Header (BCH4/ SB4)

20

Data 0

0

C

1

C

2

C

30

C

31

C

A

B

C

D

A

B

C

D

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B

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D

0 1 2 3 4 …………….. 27 28 29 30 31

A

B

C

D

- H Sync

- V Sync- Data

- X

Byte 1 Byte 2 Byte 3 Parity

LSB MSB


21

0

A

1

A

2

A

62

A

63

A

0 1 2 3 4 …………….. 27 28 29 30 31

LSB

MSB

Byte

1

Byte

3

Byte

4

Byte

2

Byte

5

Byte

7Parity

Byte

6

A

B

C

D

A

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D

1 2 3 4 5 …………….. 27 28 29 30 31

A

B

C

D

SB0

SB1SB2

SB3

Data 1

Data 2


✓ Assemble SB0 (BCH0)

22

0

B

1

B

2

B

62

B

63

B

MSB

Byte

1

Byte

3

Byte

4

LSB

Byte

2

Byte

5

Byte

7Parity

Byte

6

A

B

C

D

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0 1 2 3 4 …………….. 27 28 29 30 31

A

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0 1 2 3 4 …………….. 27 28 29 30 31

A

B

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D

SB0

SB1-SB2

SB3

Data 1

Data 2



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0

C

1

C

2

C

62

C

63

C

MSB

Byte

1

Byte

3

Byte

4

LSB

Byte

2

Byte

5

Byte

7Parity

Byte

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A

B

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0 1 2 3 4 …………….. 27 28 29 30 31

A

B

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0 1 2 3 4 …………….. 27 28 29 30 31

A

B

C

D

SB0

SB1-SB2

SB3

Data 1

Data 2



24

0

D

1

D

2

D

62

D

63

D

Byte

1

Byte

3

Byte

4

LSB

Byte

2

Byte

5

Byte

7Parity

Byte

6

0 1 2 3 4 …………….. 27 28 29 30 31

A

B

C

D

SB0

SB1-SB2

SB3

MSB

A

B

C

D

A

B

C

D

A

B

C

D

A

B

C

D

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0 1 2 3 4 …………….. 27 28 29 30 31

Data 1

Data 2



Data Island Packet Header25

26

HB/ SB4 HB0 HB1 HB2 ECC Parity

CEA 861 Packet Packet ID Packet Specific data Packet Specific data XX

Interpreting Raw Data Packet View

27

SB0 PB0 PB1 PB2 PB3 PB4 PB5 PB6 Parity

CEA 861 Packet XX DB1 DB2 DB3 DB4 DB5 DB6 XXX


CEA 861 Packet DB7 DB8 DB9 DB10 DB11 DB12 DB13 XXX


CEA 861 Packet DB14 DB15 DB16 DB17 DB18 DB19 DB20 XXX


CEA 861 Packet PB21 DB22 DB23 DB24 DB25 DB26 DB27 XXX

AVI Infoframe and Raw Packet Information Mapping

Interpreting Raw Data Packet View

Video Encoding

✓ Video Pixel Encoding

✓ RGB

✓ YCbCr 4:4:4

✓ YCbCr 4:2:2

✓ YCbCr 4:2:0

✓ Color Depth

✓ 24 bits per pixel




28

24 bits per pixel (RGB)29

½ horizontal resolution,½ vertical resolution

NO chroma subsamplingfull horizontal resolution,

full vertical resolution

What is YCbCr Pixel Encoding?“Y” is luminance (or simply “brightness”). “Cb” and “Cr” are blue-difference and red-difference chromacomponents. The difference between YCbCr and RGB is that YCbCr represents color as brightness (Y) and two color difference signals (Cb and Cr), while RGB represents color as just red, green and blue.

Chroma subsampling is a process where color information (Cb and Cr) is sacrificed in order to reduce bandwidth. Why? The human eye has good sensitivity for brightness, but poor acuity for detecting color details -- especially on a moving object.

What does “x:x:x” mean??

Subsampling scheme is expressed as “J:a:b”

J: Pixel width (usually 4).

a: Number of chrominance samples (Cr, Cb)

in the first row of J pixels.

b: Number of changes of chroma samples

(Cr, Cb) between 1st and 2nd row of pixels.

vs

4:4:4 contains a lot of color information that

your eyes can’t see well

4:2:0 contains lesscolor information but

requires ½ the bandwidth!

Introduction to DisplayPort Protocol

DisplayPort -Architecture32

✓ The Stream and Link Policy Maker manages the transport of the stream and establishing the data path and keeping the link synchronized.

✓ The Transport Layer is the Source-to-Sink data interface including A/V data packetization and inclusion of other data

✓ The Physical Layer involves the electrical interface

✓ The layered architecture of DisplayPort allows it to be extensible to other transport types

✓ The Isochronous AV Stream can be sent within a dedicated or shared transport

DisplayPort Transport Options

✓ DisplayPort 1.1a defined Single Stream Transport (SST) for use between a single Source and Sink Device.

✓ DisplayPort 1.2 added the Multi-Stream Transport (MST) option, allowing transport of up to 63 separate A/V streams across a single DisplayPort Connection.

✓ MST mode allows multiple Source and/or Sink devices to share a single connection

33

SST (single) – MST (multi) Comparison34

SST MST

Difference in isochronous and transport layers for multi

stream purpose.

SST (single stream) -Isochronous transport services

✓ Isochronous transport services over the main link

✓ Mapping of stream data to and from Main Link lanes

✓ Insertion of main stream attributes data

✓ Insertion of optional Audio stream and InfoFrame packet

35

✓ BS – Blanking Start

✓ SR- Scrambler Reset

✓ BE – Blanking End

✓ CPBS – Content Protection BS

✓ CPSR – Content Protection SR

✓ For uPacket RX with a DPCD Rev.of 1.2 or higher, the Enhanced

Framing Mode must be used when running in SST Mode.

✓ FS – Fill Start

✓ FE- Fill End

✓ SS – Secondary Data Start

✓ SE – Secondary Data End

Framing and Control Symbols

Symbol Stuffing and TU(Transfer Unit)

✓ When the packed data rate is lower than the link symbol rate, the link layer

must perform symbol stuffing

✓ The dummy data symbols must be all 00h

✓ TU size must be 32 to 64 link symbols per lane.

✓ Stuffing symbols must be framed with control symbols

37

Display Port Transfer Types

✓ Main Content - Stream Transport format for sending a single/multi stream of

video or audio

✓ Secondary Data Packet (SDP) - Used for Audio, InfoFrames, main stream

attribute data (MSA), and other data.

✓ Framing symbols/Control Symbols - Used to Identify beginning and end of

video frame

✓ Vertical Blank ID (VB-ID) – Blanking interval identification and status of audio

and video channel

✓ Copy Protection symbols –Used for copy protection protocol.

✓ Video Stream Configuration (VSC) – Additional 3D format information not

declarable in the MSA field

38

Main Link Stream Data39

✓ Inter-lane skewing increases the immunity of the link against external noise.

Dummy Data Symbols

With Inter-Lane SkewingWithout Inter-Lane Skewing

Secondary Data Packets

✓ Secondary Data Packets (SDP) are sent during the vertical and

horizontal intervals in video blanking periods

✓ Secondary Data Packet Types

✓ Main Stream Attribute Data

✓ Audio Stream

✓ Maud, Naud – Audio clock regeneration

✓ Audio Time Stamp

✓ Info frames (IEC 861 E)

✓ Compressed Video (only for eDP)

40

Video Blanking

Period

Main Stream Attribute Data

✓ MSA Data Packets are sent once per video frame during the

vertical interval

✓ ƒ The MSA describes the format of the video with a given stream

✓ Mvid & Nvid

✓ H Total & V Total

✓ HSP/HSW

✓ VSP/VSW

✓ Hstart & Vstart

41

MST (multi stream) - Isochronous Transport Service

✓ Transport of multiple streams from multiple stream sources in one or more DP Source devices to multiple Stream Sinks in one or more DP Sink devices connected via DP Branch device

✓ Connection Oriented Transport

✓ Virtual channel (VC) is established between source stream to steam sink

✓ VC needs to be established through multiple devices, it is called path

42

MST – Virtual Channel (VC), VC Payload, Link & Path43

Virtual Channel is an end-to-end, direct virtual connection between

a Stream Source and a Stream Sink

MST- Single Source to 2 Sinks

✓ Dual Display

44

MST- 2 Steam to 2 Sinks

✓ Extended Display

45

MST Device Identification 2.5.2

✓ Unique ID (GUID)

✓ RAD

46

GRL WW HQ & Lab

Santa Clara, CA

Partner Lab

Boeblingen, Germany

GRL Taiwan Labs

Taipei & Hsinchu

GRL India Lab

Bangalore

GRL Asia Pacific HQ

Singapore

GRL US R&D

Beaverton, OR

GRL Malaysia Lab

Penang

GRL Japan Lab

Yokohama

GRL China Lab

Shanghai

47

GRL-Philips HDMI 2.0 ATCs in

Taipei and Shanghai (coming soon!)

GRL DisplayPort ATCs in China, Taiwan, US, Japan

48

GRL WW HQ & Lab

Santa Clara, CA

Partner Lab

Boeblingen, Germany

GRL Taiwan Labs

TaipeiGRL India Lab

BangaloreGRL Asia Pacific HQ

Singapore

GRL US R&D

Beaverton, OR

GRL Malaysia Lab

Penang

GRL Japan Lab

YokohamaGRL China Lab

Shanghai

ATC

ATC

ATCATC

Contact Info

Taiwan

✓ How Wu, Business Development, Granite River Labs

✓ Email: [email protected]

✓ Mobile: +886-920-515-634

China and Asia Pacific

✓ Evan Sun, VP & GM, Granite River Labs

✓ Email: [email protected]

✓ Mobile: +86-185-2150-2197 or +65-9137-5672

Website Link

✓ http://graniteriverlabs.com

49

mailto:[email protected]:[email protected]://graniteriverlabs.com

Q&A

50

Documents

DP and HDMI Protocol Fundamentals...The difference between YCbCr and RGB is that YCbCr represents color as brightness (Y) and two color difference signals (Cb and Cr), while RGB represents