High-Definition Multimedia Interface

Infobox connector
name=High-Definition Multimedia Interface
type=Digital audio/video connector


logo=
caption=HDMI cable and HDMI official logo
designer=HDMI Founders
design_date=December 2002
manufacturer=HDMI Adopters
production_date=2003-Present
superseded=
superseded_by=
superseded_by_date=
external=Yes
hotplug=Yes
length=
width=Type A (13.9 mm), Type C (10.42 mm)
height=Type A (4.45 mm), Type C (2.42 mm)
electrical=
ground=
maximum_voltage=
maximum_current=
audio_signal=LPCM, Dolby Digital, DTS, DVD-Audio, Super Audio CD, Dolby TrueHD, DTS-HD Master Audio, MPCM
video_signal=480i, 480p, 576i, 576p, 720p, 1080i, 1080p, 1440p, 1600p, etc.
data_signal=Yes
data_bit_width=
data_bandwidth=10.2 Gbit/s (340 MHz)
data_devices=
data_style=TMDS
physical_connector=
num_pins=19
pinout_

pinout_caption=Type A (Female) HDMI
pin1=
pin1_name=TMDS Data2+
pin2=
pin2_name=TMDS Data2 Shield
pin3=
pin3_name=TMDS Data2–
pin4=
pin4_name=TMDS Data1+
pin5=
pin5_name=TMDS Data1 Shield
pin6=
pin6_name=TMDS Data1–
pin7=
pin7_name=TMDS Data0+
pin8=
pin8_name=TMDS Data0 Shield
pin9=
pin9_name=TMDS Data0–
pin10=
pin10_name=TMDS Clock+
pin11=
pin11_name=TMDS Clock Shield
pin12=
pin12_name=TMDS Clock–
pin13=
pin13_name=CEC
pin14=
pin14_name=Reserved (N.C. on device)
pin15=
pin15_name=SCL
pin16=
pin16_name=SDA
pin17=
pin17_name=DDC/CEC Ground
pin18=
pin18_name=+5 V Power (max 50 mA)
pin19=
pin19_name=Hot Plug Detect
pin20=
pin20_name=
pin21=
pin21_name=
pin22=
pin22_name=
pin23=
pin23_name=
pin24=
pin24_name=
pin25=
pin25_name=
pin26=
pin26_name=
pin27=
pin27_name=
pin28=
pin28_name=
pin29=
pin29_name=
pin30=
pin30_name=
pin31=
pin31_name=
pin_custom1_name=
pin_name_custom1=
pin_custom1=
pin_custom2_name=
pin_name_custom2=
pin_custom2=
pin_custom3_name=
pin_name_custom3=
pin_custom3=
pin_custom4_name=
pin_name_custom4=
pin_custom4=
pin_custom5_name=
pin_name_custom5=
pin_custom5=
pin_custom6_name=
pin_name_custom6=
pin_custom6=
pin_custom7_name=
pin_name_custom7=
pin_custom7=
pin_custom8_name=
pin_name_custom8=
pin_custom8=
pinout_notes=

The High-Definition Multimedia Interface (HDMI) is a compact audio/video connector interface for transmitting uncompressed digital streams. It represents a digital alternative to consumer analog standards such as Radio Frequency (RF) coaxial cable, composite video, S-Video, SCART, component video, D-Terminal, and VGA. HDMI connects digital audio/video sources such as set-top boxes, Blu-ray Disc players, personal computers, video game consoles, and AV receivers to compatible digital audio devices, computer monitors, and digital televisions.

HDMI supports, on a single cable, any TV or PC video format including standard, enhanced, and high-definition video along with up to 8 channels of digital audio.cite news |title=HDMI Specification 1.3a Section 6.3 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] It is independent of the various digital television standards such as ATSC and DVB as these are encapsulations of compressed MPEG video streams (which can be decoded and output as uncompressed video stream on HDMI).

HDMI products started shipping in autumn 2003. Over 800 CE and PC companies have adopted the HDMI specification (HDMI Adopters). [cite news |url=http://www.hdmi.org/press/pr/pr_20030905.aspx |title=The First HDMI Consumer Electronics Products Debut at Cedia 2003 |publisher=HDMI.org |date=September 5, 2003 |accessdate=2008-05-01] [cite news |url=http://www.hdmi.org/press/press_release.aspx?prid=89 |title=HDMI Licensing appoints Steve Venuti as new LLC President; HDMI Adoption continues to grow |publisher=HDMI.org |date=April 8, 2008 |accessdate=2008-04-30] cite news |url=http://www.hdmi.org/learningcenter/adopters_founders.aspx |title=HDMI Adopters |publisher=HDMI.org |accessdate=2008-05-09] HDMI began to appear on consumer HDTV camcorders and digital still cameras in 2006. [cite news |url=http://www.dpreview.com/news/0602/06022402samsungl85.asp |title=Samsung Camera Releases New High-Performance Digimax L85 Featuring World’s First High Definition Multimedia Interface |publisher=dpreview.com |author=Samsung |date=2006-02-24 |accessdate=2008-07-01] [cite news |url=http://www.samsungcamerausa.com/product/product_detail.asp?pid=208&category=18 |title=Digimax L85 |publisher=Samsung |author=Samsung |accessdate=2008-07-01] [cite news |url=http://reviews.cnet.com/digital-cameras/samsung-digimax-l85/4505-6501_7-31754649.html |title=Samsung Digimax L85 |publisher=cnet.com |author=Will Greenwald |date=2006-06-12 |accessdate=2008-07-01] [cite news |url=http://www.usa.canon.com/templatedata/pressrelease/20070131_hv20.html |title=Canon's new feature-packed HV20 HD camcorder expands high definition camcorder capabilities and choices for consumers |publisher=Canon |date=2007-01-31 |accessdate=2008-07-01] [cite news |url=http://reviews.cnet.com/digital-camcorders/canon-hv20-mini-dv/4505-6500_7-32172625.html |title=Canon HV20 Mini DV/HDV Camcorder |publisher=cnet.com |author=Philip Ryan |date=2007-04-04 |accessdate=2008-07-01] Shipments of HDMI are expected to exceed that of Digital Visual Interface (DVI) in 2008, driven primarily by the Consumer Electronics (CE) Market.cite news |title=In-Stat Reports DVI on the Decline as HDMI and DisplayPort Grow |publisher=reuters |url=http://www.reuters.com/article/pressRelease/idUS142983+28-Jan-2008+BW20080128|author=Brian O'Rourke |date=2008-01-28 |accessdate=2008-07-02] [cite news |title=Analyst: The DVI Interface is Dying |publisher=ExtremeTech |url=http://www.extremetech.com/article2/0,1558,2254162,00.asp?kc=ETRSS02129TX1K0000532 |author=ExtremeTech Staff |date=January 29, 2008 |accessdate=2008-01-30]

Overview

HDMI supports, on a single cable, any TV or PC video format including standard, enhanced, and high-definition video along with up to 8 channels of digital audio. HDMI encodes the video data into TMDS for uncompressed digital transmission over HDMI.

HDMI devices are manufactured to adhere to various versions of the specification, where each version is given a number such as 1.0, 1.2, or 1.3a.cite news |title=HDMI Specification 1.3a Document Revision History |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] Each subsequent version of the specification uses the same kind of cable but increases the bandwidth and/or capabilities of what can be transmitted over the cable. For example the previous maximum pixel clock rate of HDMI interface was 165 MHz which was sufficient for supporting 1080p at 60 Hz and WUXGA (1920x1200) at 60 Hz. HDMI 1.3 increased that to 340 MHz which allows for higher resolution, such as WQXGA (2560x1600), across a single digital link.cite web|url=http://www.hdmi.org/press/pr/pr_20060622.asp|title=HDMI 1.3 doubles bandwidth, delivers billions of colors for HDTVs |publisher=HDMI.org |date=June 22, 2006 |accessdate=2008-06-19]

HDMI supports 8 channel uncompressed digital audio at 192 kHz sample rate with 24 bits/sample as well as compressed audio streams such as Dolby Digital and DTS.cite news |title=HDMI Specification 1.3a Section 7 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] HDMI supports up to 8 channels of one-bit DSD audio, which is used on Super Audio CDs, at rates up to 4x that of Super Audio CD. With version 1.3, HDMI also supports lossless compressed audio streams such as Dolby TrueHD and DTS-HD Master Audio.

In the U.S., HDCP (High-bandwidth Digital Content Protection) support is a standard feature on digital TVs while in the PC industry it is becoming more common but still depends on the specific model. The first computer monitors with HDCP support started being released in 2005 and by February 2006 a dozen had been released. [cite news |title=Gateway's FPD2185W convert|21|in|mm|sing=on widescreen LCD |publisher=engadget |url=http://www.engadget.com/2005/10/04/gateways-fpd2185w-21-inch-widescreen-lcd/ |author=Peter Rojas |date=2005-10-04 |accessdate=2008-05-09] [cite news |title=Windows Vista Ready LCD Monitor Round-Up - Part 1 |publisher=FiringSquad |url=http://firingsquad.com/hardware/windows_vista-ready_hdcp_lcd_roundup/page2.asp |author=Alan Dang |date=2006-02-19 |accessdate=2008-05-09]

PCs with HDMI output using Windows Vista and Windows XP may be capable of HDMI audio output depending on specific hardware.cite news |title=HDMI Audio: Intel's Biggest Little Secret In Home Theater PCs | publisher=Intel Software Blogs | url=http://softwareblogs.intel.com/2008/04/28/hdmi-audio-intels-biggest-little-secret-in-home-theater-pcs/ |author= Aaron Brezenski |date=2008-04-28 | accessdate=2008-06-21] For example Intel's motherboard chipsets since the 945G have been capable of 7.1 channel LPCM output over HDMI. Linux supports HDMI video output through backward compatibility with DVI.

The HDMI Founders are Hitachi, Matsushita Electric Industrial (Panasonic/National/Quasar), Philips, Silicon Image, Sony, Thomson (RCA), and Toshiba. Digital Content Protection, LLC (a subsidiary of Intel) provides HDCP for HDMI. HDMI also has the support of motion picture producers Fox, Universal, Warner Bros., and Disney, system operators DirecTV and EchoStar (Dish Network), CableLabs, and Samsung.cite web|url=http://www.hdmi.org/learningcenter/faq.aspx|title=HDMI FAQ|publisher=HDMI.org|accessdate=2007-07-09]

History

HDMI 1.0 development began on April 16, 2002, with the goal of creating an AV connector backward compatible with DVI. [cite news |title=Understanding Digital Interconnects |publisher=Audioholics |url=http://www.audioholics.com/education/cables/understanding-digital-interconnects |author=Joseph D. Cornwall |date=2004-12-31 |accessdate=2008-06-23] cite news |title=HDMI - A Digital Interface Solution |publisher=HDTV Magazine |url=http://www.hdtvmagazine.com/articles/2006/07/hdmi_part_1_-_a.php |author=Rodolfo La Maestra |date=2006-06-25 |accessdate=2008-06-23] cite news |title=HDMI - High Definition Multimedia Interface |publisher=HDMI.org |url=http://www.hdmi.org/pdf/HDMI_CPTWG_4-17-02.PDF |date=2002-04-17 |accessdate=2008-06-23] At that time DVI-HDCP (DVI with HDCP) and DVI-HDTV (DVI-HDCP using the CEA-861-B video standard) were being used on HDTVs.cite news |title=White Paper - HDMI: The Digital Display Link |publisher=Silicon Image |url=http://www.hdmi.org/pdf/whitepaper/SilicaonImageHDMIWhitePaperv73(2).pdf |author=Bob O'Donnell |date=December, 2006 |accessdate=2008-06-23] [cite journal |author=Alen Koebel |year=2003 |month=February |title=DVI and HDMI: Digital A/V Interfaces for A New Age |journal=Widescreen Review |issue=69 |pages=64 |url=http://www.widescreenreview.com/ |accessdate=2008-06-24 |quote=When HDCP is added to DVI, the result is often called "DVI+HDCP." When this is used on an HDTV, HD monitor or set-top box, a further standard is usually applied: IEA/CEA-861 (currently 861-B)...the interface is commonly known as DVI-HDTV.)] HDMI 1.0 was designed to improve on DVI-HDTV by using a smaller connector and adding support for audio, enhanced support for YCbCr, and CE control functions. [cite journal |author=Alen Koebel |year=2003 |month=February |title=DVI and HDMI: Digital A/V Interfaces for A New Age |journal=Widescreen Review |issue=69 |pages=65 |url=http://www.widescreenreview.com/ |accessdate=2008-06-24 |quote=To make it even more attractive as a consumer interface, it uses a smaller connector and adds enhanced support for high-definition digital component (YCbCr) formats, going beyond those defined in IEA/CEA-861-B.)] [cite journal |author=Alen Koebel |year=2003 |month=February |title=DVI and HDMI: Digital A/V Interfaces for A New Age |journal=Widescreen Review |issue=69 |pages=65 |url=http://www.widescreenreview.com/ |accessdate=2008-06-24 |quote=Of particular note is that while IEA/CEA-861-B supports only 8bits per RGB or YCbCr component...HDMI also allows up to 12 bits per component for 4:2:2 YCbCr signals, even for 1080p/60. In comparison, professional HD mastering and D-Cinema use "only" 10-bits per 4:2:2 component,]

According to In-Stat the number of HDMI devices sold was 5 million in 2004, 17.4 million in 2005, 63 million in 2006, and 143 million in 2007. [cite news |title=HDMI Gaining as DVI Heads for a Slide |publisher=instat.com |url=http://www.instat.com/newmk.asp?ID=1558 |date=2006-01-30 |accessdate=2008-07-02] [cite news |title=Silicon Image Inc - SIMG Annual Report |publisher=Edgar Online |url=http://sec.edgar-online.com/2007/03/01/0000891618-07-000130/Section3.asp |date=2007-03-01 |accessdate=2008-07-02] HDMI is becoming the de facto standard for HDTVs and according to In-Stat around 90% of digital televisions in 2007 included HDMI. [cite news |title=HDCP— the FTA broadcasters’ perspective |publisher=EBU Technical Review |url=http://www.ebu.ch/en/technical/trev/trev_312-evain_hdcp.pdf |author=Jean-Pierre Evain |date=October 2007 |accessdate=2008-07-01] [cite news |title=DVI and HDMI Connections and HDCP Explained |publisher=Secrets of Home Theater and High Fidelity |url=http://www.hometheaterhifi.com/volume_11_4/feature-dvi-hdmi-hdcp-connections-11-2004.html |author=Brian Weatherhead |date=November 2004 |accessdate=2008-07-01] [cite news |title=The HDMI future |publisher=Secrets of Home Theater and High Fidelity |url=http://broadcastengineering.com/infrastructure/broadcasting_hdmi_future/ |author=Paul Mcgoldgrick |date=2006-08-01 |accessdate=2008-07-01] [cite news |title=HDMI: Guide To HDTV Connection Of The Future |url=http://hdtvinfozone.com/HDMI-Guide-To-HDTV-Connection.html |author=Jeff Su |accessdate=2008-07-01] [cite news |title=Testing your High Definition embedded devices using the HDMI Version 1.3 specification|publisher=Audio Design Line |url=http://www.audiodesignline.com/howto/202803907 |author=Evan Sun |date=2007-11-08 |accessdate=2008-07-01] In-Stat has estimated that 229 million HDMI devices will sell in 2008. [cite news |title=Adopted by 750+ manafacturers, HDMI is a must-have for consumer electronics |publisher=HDMI.org |url=http://www.hdmi.org/press/press_release.aspx?prid=87 |date=2008-01-05 |accessdate=2008-07-02]

pecifications

The HDMI specification defines the protocols, signals, electrical interfaces, and mechanical requirements of the standard. [cite news |title=HDMI Specification 1.3a Intellectual Property Statement |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21]

Connectors

There are three HDMI connector types with Type A and Type B defined since the HDMI 1.0 specification and Type C defined since the HDMI 1.3 specification.

The Type A connector has 19 pins with bandwidth to support all SDTV, EDTV, and HDTV modes. The plug's outside dimensions are 13.9 mm wide by 4.45 mm high. [cite news |title=HDMI Specification 1.3a Section 4.1.9.2 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] Type A is electrically compatible with single link DVI-D.cite news |title=HDMI Specification 1.3a Section 4.1.3 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21]

The Type B connector has 29 pins (21.2 mm by 4.45 mm) and can carry double the video bandwidth of Type A for use with very high-resolution future displays such as WQUXGA (3840x2400). [cite news |title=HDMI Specification 1.3a Section 4.1.9.4 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] Type B is electrically compatible with dual link DVI-D and is not used in any CE products. [cite news |title=HDMI - A Digital Interface Solution |publisher=HDTV Magazine |url=http://www.hdmi.org/pdf/whitepaper/SilicaonImageHDMIWhitePaperv73(2).pdf |author=Rodolfo La Maestra |date=2006-08-22 |accessdate=2008-06-23]

The Type C mini-connector is intended for portable devices.cite news |title=HDMI Specification 1.3a Section 4.1.1 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] It is smaller than the Type A connector (10.42 mm by 2.42 mm) but has the same 19 pin configuration. [cite news |title=HDMI Specification 1.3a Section 4.1.9.6 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] It can be connected to a Type A connector using a Type A-to-Type C connector cable.

Cable

The HDMI cable can be used to carry video, audio, and device-controlling signals (CEC). HDMI cables are often more expensive than other video cables at retail stores.cite news |url=http://gizmodo.com/gadgets/hdmi-cable-battlemodo/the-truth-about-monster-cable-+-grand-finale-part-iii-282725.php |title=The Truth About Monster Cable - Grand Finale (Part III) |publisher=Gizmodo |date=2007-07-26|accessdate=2008-06-18] However, many on-line retailers and auction sites offer un-certified HDMI cables at prices similar to coaxial and RCA cabling.

Cable length

The HDMI specification does not define a maximum cable length, but because of signal attenuation there is an upper limit to how long HDMI cables can be made.cite news |url=http://www.soundandvisionmag.com/advice/2156/ask-an-installer-hdmi-13-cable-length-limit.html |title=Ask An Installer: HDMI 1.3 Cable Length Limit |publisher=Sound & Vision |date=February/March, 2007|accessdate=2008-06-19] The length of the HDMI cable made depends on the construction quality and materials that were used. The signal attenuation and intersymbol interference which is caused by long cables can be compensated by using adaptive equalization.

HDMI 1.3 has defined two categories of cables: Category 1 certified cables which have been tested at 74.5 MHz (1080i/720p) and Category 2 certified cables which has been tested at 340 MHz (1600p) to reduce the confusion about which cables support which video formats.cite news |title=HDMI Specification 1.3a Section 4.2.6 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] Category 1 and 2 cables can either meet the required parameter specifications for inter-pair skew, far-end crosstalk, attenuation, and differential impedance or they can meet the required non-equalized/equalized eye diagram requirements. A cheaply made cable of about 5 meters (~16 ft) can be manufactured to Category 1 specifications using 28 AWG conductors. With better quality construction and materials (24 AWG conductors) an HDMI cable can reach lengths of 12 to 15 meters (~39 to 49 ft). The HDMI website has stated that many HDMI cables under 5 meters of length that were made before the HDMI 1.3 specification can work as a Category 2 cable but cautions that only Category 2 tested cables are guaranteed to work. [cite news |title=HDMI Knowledge Base | publisher=HDMI.org | url=http://www.hdmi.org/learningcenter/kb.aspx | accessdate = 2008-06-19] Long cable lengths can cause instability of HDCP and blinking on the screen due to the weakened DDC signal which HDCP requires. HDCP DDC signals must be multiplexed with TMDS video signals to be compliant with HDCP requirements for HDMI extenders based on a single Category 5/Category 6 cable. [cite news |title=HDCP License Agreement | date=2008-01-16 | publisher=Digital Content Protection, LLC. | url =http://www.digital-cp.com/files/static_page_files/D6724AFD-9B02-A253-D8D2FE5B1A10F7F7/HDCP_License_Agreement_082207.pdf | accessdate = 2008-01-24] [cite news |title=Digital Millennium Copyright Act |publisher=U.S. Copyright Office |url=http://en.wikisource.org/wiki/Digital_Millennium_Copyright_Act |date=1998-10-28 |accessdate = 2008-06-23] Several companies offer amplifiers, equalizers, and repeaters that can string several standard HDMI cables together. HDMI extenders that are based on dual Category 5/Category 6 cable can extend HDMI to 50 meters while HDMI extenders based on optical fiber can extend HDMI to 100+ meters. [cite news |url=http://www.hdmi.org/installers/longcablelengths.aspx |title=Running Long Cable Lengths |publisher=HDMI.org |accessdate=2008-06-19]

DDC channel

The Display Data Channel is a communication channel based on the I²C bus specification.cite news |title=HDMI Specification 1.3a Section 1.2 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-24] cite news |title=HDMI Specification 1.3a Section 3 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-24] HDMI specifically requires support for the Enhanced Display Data Channel (E-DDC) which is used by the HDMI source device to read the E-EDID data from the HDMI sink device to learn what audio/video formats it supports.cite news |title=HDMI Specification 1.3a Section 8.1 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-24] HDMI requires that the E-DDC support I²C standard mode speed (100 kbit/s) and allows optional support for fast mode speed (400 kbit/s). [cite news |title=HDMI Specification 1.3a Section 4.2.8 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-24] HDMI has 3 separate communication channels which are the DDC, TMDS, and the optional CEC.

TMDS channel

HDMI carries video, audio, and auxiliary data via one of three modes called the Video Data Period, the Data Island Period, and the Control Period.cite news |title=HDMI Specification 1.3a Section 5.1.2 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] During the Video Data Period, the pixels of an active video line are transmitted. During the Data Island period (which occurs during the horizontal and vertical blanking intervals), audio and auxiliary data are transmitted within a series of packets. The Control Period occurs between Video and Data Island periods.

The HDMI connection can either be single link (Type A/C) or dual link (Type B) and can have a video pixel rate of 25 MHz to 340 MHz for a single link connection or 680 MHz for a dual link connection. Video formats with rates below 25 MHz (e.g. 13.5 MHz for 480i/NTSC) are transmitted using a pixel-repetition scheme. From 24 to 48 bits per pixel can be transferred, regardless of rate. Over single link connection supports 1080p at rates up to 120 Hz and resolutions up to WQXGA.

HDMI 1.0 to HDMI 1.2a uses the CEA-861-B video standard. HDMI 1.3+ uses the CEA-861-D video standard. The CEA-861-D document defines the video timing requirements, discovery structures, and a data transfer structure. [cite news |title=Standard Details - CEA-861-D |publisher=Consumer Electronics Association |url=http://www.ce.org/standards/StandardDetails.aspx?Id=1423&number=CEA-861-D |date=2006-07-18 |accessdate=2008-06-24] The color systems that can be used by HDMI are ITU-R BT.601, ITU-R BT.709-5, and IEC 61966-2-4.cite news |title=HDMI Specification 1.3a Section 6.7.2 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] HDMI can encode the video in xvYCC (8–16 bits per component), sRGB (8–16 bits per component), YCbCr (8–16 bits per component), or YCbCr (8-12 bits per component). [cite news |title=HDMI Specification 1.3a Section 6.5 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21]

HDMI supports up to 8 channels of audio at sample sizes of 16-bit, 20-bit, and 24-bit with sample rates of 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, and 192 kHz. HDMI also supports any IEC61937-compliant audio stream, including high bitrate (lossless) streams (Dolby TrueHD, DTS-HD Master Audio).

Both HDMI and DVI use TMDS to send 10-bit characters that are encoded using 8b/10b encoding for the Video Data Period and 2b/10b encoding for the Control Period. HDMI adds the ability to send audio/auxiliary data using 4b/10b encoding for the Data Island Period. Each Data Island Period is 32 pixels in size and contains a Packet Header which describes the contents of the packet and is 32-bits in size including 8-bits of BCH ECC parity data for error correction.cite news |title=HDMI Specification 1.3a Section 5.3.1 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] Each Packet contains four subpackets each of which are 64-bits in size including 8-bits of BCH ECC parity data allowing for each Packet to carry up to 224-bits of audio data. [cite news |title=HDMI Specification 1.3a Section 5.2.3.1 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] Each Data Island Period can contain up to 18 Packets. [cite news |title=HDMI Specification 1.3a Section 5.2.3.2 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] 7 of the 15 Packet types described in the HDMI 1.3a specifications deal with audio data while 8 of the 15 Packet deal with auxiliary data. Two of Packet Types that deal with auxiliary data are the General Control Packet and the Gamut Metadata Packet. The General Control Packet carries information on AVMUTE (which mutes the audio during changes that may cause audio noise) and Color Depth (which sends the bit depth of the current video stream and is required for Deep Color). [cite news |title=HDMI Specification 1.3a Section 5.3.6 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] [cite news |title=HDMI Specification 1.3a Section 6.5.3 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] The Gamut Metadata Packet carries information on the color space being used for the current video stream and is required for xvYCC. [cite news |title=HDMI Specification 1.3a Section 5.3.12 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] [cite news |title=HDMI Specification 1.3a Section 6.7.2 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] [cite news |title=HDMI Specification 1.3a Section 6.7.3 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21]

Consumer Electronics Control channel

The Consumer Electronics Control (CEC) channel wiring is mandatory although implementation of CEC in a product is optional. [cite news |title=HDMI Specification 1.3a Section 8.1 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] The CEC channel uses the industry standard AV Link protocol, is used for remote control functions, is a one-wire bidirectional serial bus, and was defined in HDMI Specification 1.0 and updated in HDMI 1.2, HDMI 1.2a, and HDMI 1.3a (added timer and audio commands). [cite news |title=HDMI Specification 1.3a CEC Section 1.2 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] [cite news |title=HDMI Specification 1.3a CEC Section 3.1 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] [cite news |title=HDMI Specification 1.3a CEC Section 5 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] [cite news |title=HDMI Specification 1.3a CEC Section 1.3 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21]

The CEC feature is used to allow the user to command and control multiple CEC-enabled boxes with one remote control and for individual CEC-enabled boxes to command and control each other without user intervention. An example of the latter is to allow the DVD player, when the drawer closes with a disk, to command the TV and the intervening A/V receiver (all with CEC) to power-up, select the appropriate HDMI ports, and auto-negotiate the proper video mode and audio mode. No remote control command is needed. Similarly, this type of equipment can be programmed to return to sleep mode when the movie ends, perhaps by checking the real-time clock. If it is later than 11:00 p.m., for example, and the user does not specifically command the systems with the remote control, the systems turn off on command from the DVD player.

Alternative names for CEC are Anynet (Samsung), Aquos Link (Sharp), BRAVIA Theatre Sync (Sony), Kuro Link (Pioneer), Regza Link (Toshiba), RIHD (Onkyo), Simplink (LG), Viera Link/EZ-Sync (Panasonic/JVC), Easylink (Philips) and NetCommand for HDMI (Mitsubishi).

Compatibility with DVI

The DVI signal is electrically compatible with HDMI video signal; no signal conversion needs to take place when an adapter is used and consequently no loss in video quality occurs.cite news |title=HDMI Specification 1.3a Appendix C |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] As such HDMI is backward compatible with Digital Visual Interface carrying digital video (DVI-D or DVI-I, but not DVI-A) used on modern computer monitors and graphics cards. This means that a DVI-D source can drive an HDMI monitor, or vice versa, by means of a suitable adapter or cable, but the audio and remote control features of HDMI will not be available. Additionally, without support for High-bandwidth Digital Content Protection (HDCP) on the DVI input, the signal source will prevent the end user from viewing or recording HDCP protected content. [cite news |title=Digital Content Protection FAQs | publisher=Digital Content Protection, LLC. | url=http://www.digital-cp.com/faqs | accessdate=2008-06-21] (Note that HDCP is available on some DVI connections)

Content protection

HDMI can use HDCP to encrypt the signal if required by the source device. CSS, CPPM, and AACS requires the use of HDCP on HDMI when playing back encrypted DVD-Video, DVD-Audio, and Blu-ray Disc. The HDCP Repeater bit controls the authentication and switching/distribution of an HDMI signal. According to HDCP Specification 1.2 beginning with HDMI CTS 1.3a, any system which implements HDCP must do so in a fully-compliant manner. HDCP testing which was previously only a requirement for optional tests such as the “Simplay HD” testing program is now part of the requirements for HDMI compliance. [cite news |title=Retailer Requires ‘Simplay’ HDMI Testing |publisher=TWICE |url=http://www.twice.com/article/CA6398917.html |date=2006-12-11 |accessdate=2008-06-21] [cite news |title=HDMI Specification 1.3a Section 9.2 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] cite news |url=http://www.hdmi.org/pdf/2007_11HDMI_ComplianceTestingPolicies.pdf |title=HDMI Compliance Testing Policies and Procedures |publisher=HDMI.org |accessdate=2008-05-04]

Versions

HDMI devices are manufactured to adhere to various versions of the specification, where each version is given a number such as 1.0, 1.2, or 1.3a. Each subsequent version of the specification uses the same kind of cable but increases the bandwidth and/or capabilities of what can be transmitted over the cable. A product listed as having an HDMI version does not necessarily mean that it will have all of the features that are listed for that version since some HDMI features are optional such as Deep Color and xvYCC (which is branded by Sony as "x.v.Color").cite news |title=Home Toys Interview December 2007|publisher=hometoys|url=http://www.hometoys.com/htinews/dec07/interviews/hdmi/hdmi.htm |author=Steve Venuti |date=December, 2007 |accessdate=2008-06-21] [cite news |title=Transformation is Sony's CES theme |publisher=Sony |url=http://news.sel.sony.com/en/press_room/consumer/television/release/27367.html/ |date=2007-01-07 |accessdate=2008-06-19]

HDMI 1.0

Released December 9, 2002.
* A single cable digital audio/video connector interface with a maximum TMDS bandwidth of 4.9 Gbit/s. Supports up to 3.96 Gbit/s of video bandwidth (1080p60 Hz or UXGA) and 8 channel LPCM/192 kHz/24-bit audio.

HDMI 1.1

Released May 20, 2004.
* Added support for DVD Audio.

HDMI 1.2

Released August 8, 2005.
* Added support for One Bit Audio, used on Super Audio CDs, up to 8 channels.
* Availability of HDMI Type A connector for PC sources.
* Ability for PC sources to use native sRGB color-space while retaining the option to support the YCbCr color space.
* Requirement for HDMI 1.2 and later displays to support low-voltage sources.

HDMI 1.2a

Released December 14, 2005.
* Fully specifies Consumer Electronic Control (CEC) features, command sets, and CEC compliance tests.

HDMI 1.3

Released June 22, 2006. [cite news|url=http://www.twice.com/article/CA6345214.html?text=hdmi|title=HDMI 1.3 Connections Due By Year End|author=Joseph Palenchar |publisher=TWICE |date=June 19, 2006 |accessdate=2007-08-02]
* Increases single-link bandwidth to 340 MHz (10.2 Gbit/s)
* "Optionally" supports Deep Color with 30-bit, 36-bit, and 48-bit xvYCC, sRGB, or YCbCr compared to 24-bit sRGB or YCbCr in previous HDMI versions.
* Incorporates automatic audio syncing (Audio video sync) capability.
* "Optionally" supports output of Dolby TrueHD and DTS-HD Master Audio streams for external decoding by AV receivers. [cite web|url=http://www.hdtvmagazine.com/articles/2006/08/hdmi_part_5_-_audio_in_hdmi_versions.php|title=HDMI Part 5 - Audio in HDMI Versions |publisher=HDTVMagazine.com |date=August 8, 2006 |accessdate=2007-08-02] TrueHD and DTS-HD are lossless audio codec formats used on Blu-ray Discs and HD DVDs. If the disc player can decode these streams into uncompressed audio, then HDMI 1.3 is not necessary, as all versions of HDMI can transport uncompressed audio.
* Cable Categories 1 and 2 defined. Category 1 cable is tested up to 74.25 MHz while Category 2 cable is tested up to 340 MHz.
* Availability of a new Type C mini-connector for portable devices. [cite news|url=http://www.hdbeat.com/2006/06/28/pics-of-the-hdmi-mini-connector |title=Pics of the HDMI-mini connector |author=Matt Burns |publisher=engadgetHD |date=2006-06-28 |accessdate=2008-06-23]

HDMI 1.3a

Released November 10, 2006.
* Cable and Sink modifications for Type C
* Source termination recommendation
* Removed undershoot and maximum rise/fall time limits.
* CEC capacitance limits changed
* sRGB video quantization range clarification
* CEC commands for timer control brought back in an altered form, audio control commands added.
* Concurrently released compliance test specification included.

HDMI 1.3b

Released March 26, 2007.cite news |url=http://www.hdmi.org/learningcenter/kb.aspx |title=Knowledge Base: HDMI Versions |publisher=HDMI.org |accessdate=2008-05-04] cite news |url=http://www.hdmi.com.au |title=HDMI: Home & News |publisher=HDMI.com.au |accessdate=2008-05-04]
* HDMI compliance testing revisions. Has no effect on HDMI features or functions since the testing is for products based on the HDMI 1.3a specification.

HDMI 1.3b1

Released November 9, 2007.
* HDMI compliance testing revisions which added testing requirements for HDMI Type C mini-connector. Has no effect on HDMI features or functions since the testing is for products based on the HDMI 1.3a specification.

HDMI and Blu-ray Disc players

Blu-ray Disc, introduced in 2006, offers new high-fidelity audio features that require HDMI for best results. Dolby Digital Plus (DD+), Dolby TrueHD, and DTS-HD Master Audio use bitrates exceeding S/PDIF's capacity. [cite news |url=http://www.epanorama.net/documents/audio/spdif.html |title=SPDIF |publisher=ePanorama.net|accessdate=2008-06-21] HDMI 1.3 can transport DD+, TrueHD, and DTS-HD bitstreams in compressed form. This capability allows for an AV receiver with the necessary decoder to decode the compressed audio stream.

Blu-ray permits secondary audio decoding whereby the disc content can tell the player to mix multiple audio sources together before final output. [cite web| url=http://www.highdefdigest.com/news/show/Joshua_Zyber/High-Def_FAQ:_Blu-ray_Profiles_Explained/1186| title=High-Def FAQ: Blu-ray Profiles Explained| first=Joshua| last=Zyber| publisher=highdefdigest.com| date=2007-11-23| accessdate=2008-06-21] Some Blu-ray players will consequently handle audio-decoding internally and can output LPCM audio all the time. Multi-channel LPCM can be transported over an HDMI connection and as long as the AV receiver supports multi-channel LPCM audio over HDMI, and supports HDCP, the audio reproduction is equal in resolution to HDMI 1.3 bitstream output. Some low cost AV receivers, such as the Onkyo TX-SR506, do not support audio processing over HDMI and are labeled as "HDMI pass through" devices. [cite news |url=http://www.post-gazette.com/pg/06357/748450-96.stm |title=Sound Advice: Best receiver flying under his radar |author=Don Lindich |publisher=post-gazette now |date=2006-12-23 |accessdate=2008-06-30] [cite news |url=http://www.us.onkyo.com/model.cfm?m=TX-SR506&class=Receiver&p=i |title=TX-SR506 |publisher=Onkyo |accessdate=2008-06-21]

Note that a given product may choose to implement a subset of the given HDMI version. Certain features such as Deep Color and xvYCC support are optional.

{| class="wikitable"
-! HDMI version! 1.0! 1.1! 1.2
1.2a! 1.3! 1.3a
1.3b
1.3b1
-
sRGB
y
y
y
y
y
-
YCbCr
y
y
y
y
y
-
8 channel LPCM/192 kHz/24-bit audio capability
y
y
y
y
y
-
Blu-ray Disc video and audio at full resolutionref label|bd|F|F
y
y
y
y
y
-
Consumer Electronic Control (CEC)ref label|cec|G|G
y
y
y
y
y
-
DVD-Audio support
n
y
y
y
y
-
Super Audio CD (DSD) supportref label|dsd|H|H
n
n
y
y
y
-
Deep Color
n
n
n
y
y
-
xvYCC
n
n
n
y
y
-
Auto lip-sync
n
n
n
y
y
-
Dolby TrueHD bitstream capable
n
n
n
y
y
-
DTS-HD Master Audio bitstream capable
n
n
n
y
y
-
Updated list of CEC commandsref label|cecc|I|I
n
n
n
n
y:note label|bppx|A|A 36-bit support is mandatory for Deep Color compatible CE devices with 48-bit support being optional. [cite news |title=HDMI Specification 1.3a Section 6.2.4 |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] :note label|mres1|B|B Maximum resolution is based on CVT-RB blanking which is a VESA standard for non-CRT based displays. [cite news |url=http://www.nvidia.com/object/advanced_timings.html |title=Advanced Timing and CEA/EIA-861B Timings |publisher=NVIDIA |accessdate=2008-06-18] Using CVT-RB blanking 1920x1200 would have a video bandwidth of 3.69 Gbit/s and 2560x1600 would have a video bandwidth of 8.12 Gbit/s.:note label|mres2|C|C Using CVT-RB blanking would have a video bandwidth of 8.12 Gbit/s.:note label|mres3|D|D Using CVT-RB blanking would have a video bandwidth of 7.91 Gbit/s.:note label|mres4|E|E Using CVT-RB blanking would have a video bandwidth of 7.39 Gbit/s.:note label|bd|F|F Even for audio bitstream formats that a given HDMI version cannot transport it may still be possible to decode the bitstream in the player and transmit the audio as PCM with no loss of quality.:note label|cec|G|G CEC has been in the HDMI specification since version 1.0 but has only begun to be used in CE products with HDMI version 1.3a.:note label|dsd|H|H Playback of SACD may be possible for older HDMI versions if the signal source (such as the Oppo 970) converts to LPCM. For those receivers that have only PCM DAC converters and not DSD this means that no additional resolution loss occurs.:note label|cecc|I|I Large number of additions and clarifications for CEC commands. One addition is CEC command allowing for volume control of an AV receiver.

HDMI and computers

Several PC graphics cards and motherboards include HDMI output. There has been some attention to the problem of playing back Bluray and HD-DVD content on a computer with access to optimum audio and video quality. The issue of getting full-resolution audio from a computer using HDMI is discussed in [http://www.anandtech.com/video/showdoc.aspx?i=3411 this] article.

Relationship with DisplayPort

Another audio/video connector interface is DisplayPort, which had version 1.0 approved in May 2006 and is supported in a few computer monitors. Dell has begun selling CE Displays that feature Displayport functionality. The DisplayPort website states that DisplayPort is expected to complement HDMI. [cite news |title=DisplayPort FAQ |publisher=DisplayPort website |url=http://www.displayport.org/FAQ/default.htm |accessdate=2008-06-19]

There are a few advantages that HDMI has over DisplayPort such as support for the xvYCC color space, Dolby TrueHD and DTS-HD MA bitstream support, CE control signals, and compatibility with DVI. [cite news |title=HDMI Specification 1.3a |publisher=HDMI Licensing, LLC. |url=http://www.hdmi.org |date=2006-11-10 |accessdate=2008-06-21] [cite news |title=DisplayPort 1.1a Standard |publisher=VESA.org |url=http://www.displayport.org |date=2008-01-11 |accessdate=2008-06-23] DisplayPort has an advantage that it is currently royalty free which might allow it to be cheaper to implement while the HDMI royalty is 4 cents per device. [cite news |title=HDMI Adopter Terms |publisher=HDMI.org |url=http://www.hdmi.org/manufacturer/terms.aspx |accessdate=2008-06-23] Most of the DisplayPort supporters are computer companies with its largest supporter being Dell which has released two computer monitors that support both DisplayPort and HDMI. [cite news |title=Dell's 3008WFP convert|30|in|mm|sing=on-inch LCD with DisplayPort sneaks available -- in US too |publisher=engadget |url=http://www.engadget.com/2007/12/18/dells-3008wfp-30-inch-lcd-with-displayport-sneaks-available/ |author=Paul Miller |date=2007-12-18 |accessdate=2008-06-18] [cite news |title=Dell's convert|24|in|mm|sing=on-inch 2408WFP monitor with DisplayPort (and everything else) now available |publisher=engadget |url=http://www.engadget.com/2008/01/17/dells-24-inch-2408wfp-monitor-with-displayport-and-everything/ |author=Thomas Ricker |date=2008-01-17 |accessdate=2008-06-18]

ee also

* Deep Color
* Digital Visual Interface
* DisplayPort
* HD ready
* HDMI Extender
* List of display interfaces
* xvYCC

References

External links

* [http://www.hdmi.org HDMI Licensing, LLC.]
* [http://www.pacificcable.com/HDMI_Tutorial.htm HDMI Tutorial]
* [http://octavainc.com/HDMI%20switch%20Insiders%20Guide.htm HDMI switching]