High-Definition Multimedia Interface

From Wikipedia, the free encyclopedia

You have new messages (last change).
High-Definition Multimedia Interface


HDMI official logo
Type Digital audio/video connector
Production history
Designer The HDMI group
Designed December 2002
Produced 2003
Specifications
Hot plugable yes
External yes
Audio signal PCM,DVD-Audio,Super Audio CD,Dolby TrueHD,DTS-HD Master Audio
Video signal 480i, 480p, 576i, 576p, 720p, 1080i, 1080p, 1440p, etc.
Bandwidth 10.2 Gbps at 340 Mpixels/sec
Pins 19
Pin out

Type A (Receptacle) HDMI
Pin 1 TMDS Data2+
Pin 2 TMDS Data2 Shield
Pin 3 TMDS Data2–
Pin 4 TMDS Data1+
Pin 5 TMDS Data1 Shield
Pin 6 TMDS Data1–
Pin 7 TMDS Data0+
Pin 8 TMDS Data0 Shield
Pin 9 TMDS Data0–
Pin 10 TMDS Clock+
Pin 11 TMDS Clock Shield
Pin 12 TMDS Clock–
Pin 13 CEC
Pin 14 Reserved (N.C. on device)
Pin 15 SCL
Pin 16 SDA
Pin 17 DDC/CEC Ground
Pin 18 +5 V Power
Pin 19 Hot Plug Detect

The High-Definition Multimedia Interface (HDMI) is a DRM-enabled all-digital audio/video interface capable of transmitting uncompressed streams. HDMI provides an interface between any compatible digital audio/video source, such as a set-top box, a DVD player, a PC, a video game system, or an AV receiver and a compatible digital audio and/or video monitor, such as a digital television (DTV).

It is a modern replacement for older analogue standards such as SCART or the RCA connector.

Contents

[edit] General notes

HDMI supports any TV or PC video format, including standard, enhanced, or high-definition video, plus multi-channel digital audio on a single cable. It is independent of the various DTV standards such as ATSC, and DVB (-T,-S,-C), as these are encapsulations of the MPEG movie data streams, which are passed off to a decoder, and output as uncompressed video data on HDMI. HDMI encodes the video data into TMDS for transmission digitally over HDMI.

Devices are manufactured to adhere to various versions of the specification, where each version is given a number, such as 1.0 or 1.3. Each concurrent version of the specification uses the same cables, but increases the throughput and capabilities of what can be transmitted over the cable. For example, previously, the maximum pixel rate of the interface was 165Mpixels/second, sufficient for supporting 1080p at 60Hz or UXGA (1600x1200), but HDMI 1.3 increased that to 340Mpixels/second, providing support beyond the highest resolution computer monitors available today. See the Versions section for details.

HDMI also includes support for 8-channel uncompressed digital audio at 192kHz sample rate with 24 bits/sample as well as any compressed stream such as Dolby Digital, or DTS. HDMI supports up to 8 channels of one-bit audio, such as that used on Super Audio CDs at rates up to 4x that used by SuperAudio CD. With version 1.3, HDMI now also supports very high bitrate lossless compressed streams such as Dolby TrueHD and DTS-HD Master Audio.

The standard Type A HDMI connector has 19 pins, and a higher resolution version called Type B, has been defined, although it is not yet in use. Type B has 29 pins, allowing it to carry an expanded video channel for use with very high-resolution future displays. Type B is designed to support resolutions higher than WQSXGA (3200x2048).

Type A HDMI is backward-compatible with the single-link 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 display, the signal source may prevent the end user from viewing or especially copying certain restricted content. (While all HDMI displays currently support HDCP, most DVI PC-style displays do not.) Type B HDMI is similarly backward-compatible with dual-link DVI.

The HDMI Founders include consumer electronics manufacturers Hitachi, Matsushita Electric Industrial (Panasonic/National/Quasar), Philips, Sony, Thomson (RCA), Toshiba, and Silicon Image. Digital Content Protection, LLC (a subsidiary of Intel) is providing HDCP for HDMI. In addition, HDMI has the support of major motion picture producers Fox, Universal, Warner Bros., and Disney, and system operators DirecTV and EchoStar (Dish Network) as well as CableLabs and Samsung.

[edit] Specifications

Each channel in HDMI can be purposed to carry audio, video, multimedia, or device-controlling signals, or a combination of these signals.

[edit] TMDS channel

The Transition Minimized Differential Signaling (TMDS) channel:

  • Carries video, audio, and auxiliary data via one of three modes called the Video Data Period, the Data Island Period, and the Control Period. 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.
  • Signaling method: Formerly according to DVI 1.0 spec. Single-link (Type A HDMI) or dual-link (Type B HDMI).
  • Video pixel rate: 25 MHz to 340 MHz (Type A, as of 1.3) or to 680 MHz (Type B). Video formats with rates below 25 MHz (e.g. 13.5 MHz for 480i/NTSC) transmitted using a pixel-repetition scheme. From 24 to 48 bits per pixel can be transferred, regardless of rate. Supports 1080p at rates up to 120Hz and WQSXGA [1].
  • Pixel encodings: RGB 4:4:4, YCbCr 4:4:4 (8-16 bits per component); YCbCr 4:2:2 (12 bits per component)
  • Audio sample rates: 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz.
  • Audio channels: up to 8.
  • Audio streams: any IEC61937-compliant stream, including high bitrate (lossless) streams (Dolby TrueHD, DTS-HD Master Audio).

[edit] Display Data Channel

The Display Data Channel (DDC):

  • Allows source to interrogate capabilities of destination device.
  • I²C signaling with 100 kHz clock.
  • E-EDID data structure according to CEA-861D and VESA Enhanced EDID (V1.3).

[edit] Consumer Electronics Control channel

The Consumer Electronics Control (CEC) channel is optional to implement, but wiring is mandatory. The channel:

  • Uses the industry standard AV Link protocol
  • Used for remote control functions.
  • One-wire bidirectional serial bus.
  • Defined in HDMI Specification 1.0, updated in HDMI 1.2A.

[edit] Content protection

[edit] Versions

Devices are manufactured to adhere to various versions of the specification, where each version is given a revision number. Each concurrent version of the specification uses the same cables, but increases the throughput and capabilities of what can be transmitted over that cable.

[edit] HDMI 1.0

Released December 2002.

  • Single-cable digital audio/video connection with a maximum bitrate of 4.9Gbps. Supports up to 165Mpixels/sec video (1080p60Hz or UXGA) and 8-channel/192kHz/24-bit audio.

[edit] HDMI 1.1

Released May 2004.

  • Added support for content protection metadata required for DVD Audio.

[edit] HDMI 1.2

Released August 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 RGB color-space while retaining the option to support the YCbCr CE color space.
  • Requirement for HDMI 1.2 and later displays to support low-voltage sources.

[edit] HDMI 1.2a

Released December 2005.

  • Fully specifies Consumer Electronic Control (CEC) features, command sets, and CEC compliance tests.

[edit] HDMI 1.3

Released 22 June 2006.[1] [2]

  • Increases single-link bandwidth to 340 Mhz (10.2 Gbps)
  • Supports 30-bit, 36-bit, and 48-bit (RGB or YCbCr) color depths or over one billion colors, up from 24-bit in previous versions.
  • Supports xvYCC color standards.
  • Incorporates automatic audio syncing (lip sync) capability.
  • Supports output of Dolby TrueHD and DTS-HD Master Audio streams for external decoding by AV receivers.[3] TrueHD and DTS-HD are lossless audio codec formats used on HD DVDs and Blu-ray Discs. If the disk player can decode these streams into uncompressed audio, then HDMI 1.3 is not necessary, as all versions of HDMI can transport uncompressed audio.
  • Availability of a new mini connector for devices such as camcorders.[4]
  • PlayStation 3 is the first product available on consumer market with HDMI 1.3.

[edit] Cable length

The HDMI specification does not define a maximum cable length. As with all cables, signal attenuation becomes too high at a certain length. Instead, HDMI specifies a minimum performance standard. Any cable meeting that specification is compliant. Different construction quality and materials will enable cables of different lengths. In addition, higher performance requirements must be met to support video formats with higher resolutions and/or frame rates than the standard HDTV formats.

The signal attenuation and intersymbol interference caused by the cables can be compensated by using Adaptive Equalization.

HDMI 1.3 defined two categories of cables: Category 1 (standard or HDTV) and Category 2 (high-speed or greater than HDTV) to reduce the confusion about which cables support which video formats. Using 28 AWG, a cable of about 5 meters (~16 feet) can be manufactured easily and inexpensively to Category 1 specifications. Higher-quality construction (24 AWG, tighter construction tolerances, etc.) can reach lengths of 12 to 15 meters. In addition, active cables (fiber optic or dual Cat-5 cables instead of standard copper) can be used to extend HDMI to 100 meters or more. Some companies also offer amplifiers, equalizers and repeaters that can string several standard (non-active) HDMI cables together.

[edit] See also

[edit] References

  1. ^ HDMI 1.3 Press Release.
  2. ^ Joseph Palenchar (2006-06-19). HDMI 1.3 Connections Due By Year End.
  3. ^ HDMI Part 5 - Audio in HDMI Versions (2006-08-09).
  4. ^ Pics of the HDMI-mini connector.

[edit] External links


v • d • e
Audio and video connectors
Single conductor: Binding post | Banana plug | Fahnestock clip
Audio: RCA | Jack plug | XLR | DIN / Mini-DIN | BNC | DB25 | Speakon | TosLink
Video: DVI / Mini-DVI / UDI | RCA | VGA / Mini-VGA | DFP | P&D | BNC | DIN / Mini-DIN | 13W3 | D4 | DisplayPort
Multi: ADC | HDMI | TRS | SCART | F | Belling-Lee | DisplayPort
Retrieved from "http://en.wikipedia.org../../../h/i/g/High-Definition_Multimedia_Interface_5135.html"