HDMI (High-Definition Multimedia Interface) is a compact audio/video interface or a connector for transmitting uncompressed digital data. By delivering crystal-clear, all-digital audio and video via a single cable, HDMI dramatically simplifies cabling and helps provide consumers with the highest-quality home theater experience.
HDMI is the de facto standard digital connection for consumer electronics products.
· De facto standard is a custom, convention, product, or system that has achieved a dominant position by public acceptance or market forces (such as early entrance to the market).
It is a digital alternative to consumer analog standards, such as radio frequency (RF) coaxial cable, composite video, S-Video, component video, VGA or D-Terminal, SCART.
1.1.1. Composite Video
o An analog television (picture only) signal modulated onto an RF carrier.
o Contains all required video information, It is a composite of three source signals called Y, U and V with sync pulses. Y represents the brightness or luminance of the picture and includes synchronizing pulses, so that by itself it could be displayed as a monochrome picture. U and V represent hue and saturation or chrominance; between them they carry the color information
1.1.1. Separate video/S-Video
o An analog video transmission scheme.
o Video information is encoded on two channels: luma (luminance, intensity) and chroma (color).
o The luminance (Y; gray-scale) signal and chrominance (C; color) information are carried on separate, synchronized signal and ground pairs
1.1.2. . Component Video
o A video signal that has been split into two or more components
o A type of analog video information that is transmitted or stored as three separate signals.
o Generally refers to analog YPbPr component video with sync on luma.
1.1.4. Video Graphics Array (VGA)
o Carry analog component RGBHV (red, green, blue, horizontal sync, vertical sync) video signals, and VESA Display Data Channel (VESA DDC) data.
o VGA connector is a three-row 15-pin DE-15 connector which is conventionally called RGB connector or D-sub 15.
o The same VGA cable can be used with a variety of supported VGA resolutions.
BACKGROUND
2.1. OVERVIEW OF HDMI
An Interface acts as medium of interaction or communication between any two devices. It's a single cable and user-friendly connector that replaces the maze of cabling behind the home entertainment center.
It’s the one cable that transmits digital video, digital audio, and control data through a single high-speed link, making it the best and easiest way to turn your TV into a home entertainment powerhouse. HDMI provides an interface between any A/V source, such as a set-top box, Blu-ray Disc players, DVD player, personal computers (PCs), video game consoles (such as the PlayStation 3 and Xbox 360), and AV receivers such as compatible digital audio devices, computer monitors, video projectors, and digital television(DTV) over a single cable.
It is designed and founded by a group of 7 companies – Hitachi, Panasonic, National, Quasar, Philips, Silicon Image, Sony, Thomson, and Toshiba in the year 2002. Over 1,000 licensed HDMI Adaptors worldwide, an increase of 11% compared to the year 2009.
2.2. ABOUT MULTIMEDIA AND HIGH DEFINITION(HD)
Multimedia includes a combination of text, audio, still images, animation and video content forms. HDMI delivers highest-quality standard, enhanced, or high-definition video, plus multi-channel digital audio on a single cable. It is simply a connector between high definition devices.
High-definition refers to an increase in display or visual resolution in context of HD Video and increase in audio sound effects in context of HD audio.
· High-definition video or HD video refers to any video system of higher resolution than standard-definition (SD) video, and most commonly involves display resolutions of 1,280×720 pixels (720p) or 1,920×1,080 pixels (1080i/1080p).
2.3. WHAT ARE HDTVS?
High- definition television (or HDTV, or just HD) refers to video having resolution substantially higher than traditional television systems (standard-definition TV, or SDTV, or SD). HD has one or two million per frame, roughly five times that of SD. Early HDTV broadcasting used analog techniques, but today HDTV is digitally broadcast using video compression.
Most popular application of HDMI is HDTVs. Before the development of high-definition televisions, most TVs displayed pictures in what is now known as standard definition. The picture was roughly square - its aspect ratio was 4:3. Its resolution, or the number of dots that make up the picture on the screen, was about 704 x 480 pixels. Finally, Older TVs relied on analog signals, which travel as a constantly varying electrical current.
HDTVs, on the other hand, are digital. They use information in the form of ones and zeros. This information travels through cables as distinct electrical pulses. HDTVs have an aspect ratio of 16:9, so the picture is rectangular. They also have a higher resolution - current HDTV standards allow for resolutions of up to 1920 x 1080 pixels. HDTV signals can also be progressive, meaning that the each frame of the moving image is a whole picture rather than half of one.
HOW HDMI WORKS? (COMMUNICATION CHANNEL PROTOCOLS)
HDMI has three physically separate communication channels, which are the DDC, TMDS, and the optional CEC.
3.1. THE DISPLAY DATA CHANNEL (DDC)
The Display Data Channel or DDC is a collection of digital communication protocols between a computer display and a graphics adapter that enables the display to communicate its supported display modes to the adapter and to enable the computer host to adjust monitor parameters, such as brightness and contrast.
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. 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).
The DDC suite of standards aims to provide a "plug and play" experience for computer displays.
3.2. TRANSITION MINIMIZED DIFFERENTIAL SIGNALING (TMDS)
HDMI uses transition minimized differential signaling (TMDS) to move information from one place to another. TMDS is a way of encoding the signal to protect it from degrading as it travels down the length of the cable. Here's what happens:
· HDMI encodes the video data into TMDS for transmission digitally over HDMI. Transition Minimized Differential Signaling (TMDS) is a technology for transmitting high-speed serial data and is used by the DVI and HDMI video interfaces, as well as other digital communication interfaces developed by Silicon Image.
· TMDS Clock channel constantly runs at the pixel rate of the transmitted video. So it enables to transfer huge amounts of data through a shielded cable that each channel capable of transfer rates up to 3.4Gbps, a total 10.2Gbps up to 48-bit resolution. The video pixels can be encoded in either RGB, YCBCR 4:4:4 or YCBCR 4:2:2 formats.
· TMDS is a channel which carries video, and/or audio through one of three modes:
i. Video Data Period:
The pixel of an active video are transmitted.
ii. Data Instant Period:
Audio and auxiliary data are transmitted with a series of packets. This auxiliary data includes Info Frames and other data describing the active audio or video stream or describing the transmitter.
iii. Control Period:
Occurs between video and data is land periods. It is used when no video, audio, or auxiliary data needs to be transmitted.
In TDMS the transmitter incorporates an advanced coding algorithm which reduces electromagnetic interference over copper cables and enables robust clock recovery at the receiver to achieve high skew tolerance for driving longer cables as well as shorter low cost cables. The method is a form of 8b/10b encoding.
The sending device, such as an HD-DVD player, encodes the signal to reduce the number of transitions between one (on) and zero (off). Think of each transition as a sharp drop-off. As the signal travels, this drop-off can begin to wear away, degrading the signal. The encoding step helps protect signal quality by reducing the number of chances for the signal to degrade.
A two-stage process converts an input of 8 bits into a 10 bit code with particular desirable properties. In the first stage each bit is either XOR or XNOR transformed against the previous bit, whilst the first bit is not transformed at all. The encoder chooses between XOR and XNOR by determining which will result in the fewest transitions; the ninth bit is added to show which was used. In the second stage, the first eight bits are optionally inverted to even out the balance of ones and zeros and therefore the sustained average DC level. The tenth bit is added to indicate whether this inversion took place.
Also one of the cables in the twisted pair carries the signal itself. The other carries an inverse copy of the signal. The receiving device, such as an HDTV, decodes the signal. It measures the differential, or the difference between the signal and its inverse. It uses this information to compensate for any loss of signal along the way.
3.3.CONSUMER ELECTRONICS CONTROL (CEC)
Consumer Electronics Control (CEC) is a feature designed to allow the user to command and control two or more CEC-enabled boxes, that are connected through HDMI, by using only one of their remote controls. (E.g. controlling a Television set, Set-top box and DVD player using only the remote control of the TV). CEC also allow for individual CEC-enabled devices to command and control each other without user intervention.
If your devices support CEC, it allows them to send instructions to one another. For example, an HD-DVD player could automatically turn on a home-theater receiver and an HDTV when it started playing a disk.
CEC protocol provides high-level control functions such as:
· One Touch Play
· System Standby
· One Touch Record
· Deck Control
· Tuner Control
HDMI CABLE AND SIGNAL CONFIGURATIONS
4.1 .HDMI CABLE CONFIGURATION
From the HDMI connector's pins, signals travel through twisted pairs of copper cable. Three audio and video channels travel through two pins each, for a total of six pins. The TMDS clock, which allows devices to synchronize the incoming data, travels through one pair of pins. Each of these four total pairs has a shield - another wire that protects it from interference from its neighbors. The TMDS channels, the clock and the shields make up the bulk of the cable pairs inside the HDMI cable.
The other signals that travel through the HDMI cable need only one pin. One such channel is the consumer electronics channel (CEC). The hot plug detect channel, which uses one pin, senses when you plug in or unplug a device, re-initializing the HDMI link if necessary. The one-pin display data channel (DDC) carries device information. DDC is used for configuration and status exchange between a single Source and a single Sink. Other channels carry encryption data and electricity to power communication between devices.
With 19 wires wrapped in a single cable that resembles a USB wire, HDMI is able to carry a bandwidth of up to 10.2 GB/S (gigabytes per second).
4.2 HDMI SIGNAL CONFIGURATION
HDMI transmits all ATSC HDTV standards and supports 8-channel, 192 kHz, uncompressed digital audio, all currently-available compressed formats & lossless digital audio formats with bandwidth to spare to accommodate future enhancements and requirements.
· ATSC is a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks.
· Audio signals –DVD audio, Super Audio CD, Dolby Digital , Dolby DigitalPlus
· Video signals – 480i, 480p, 576i, 576p, 720p, 1080i, 1080p, 1440p, 1600p, 2160p
· Bandwidth – up to 10.2 GB/S (340 MHz)
· Protocol – TDMS (Transition Minimized Differential Signaling)
HDMI OVER EXISTING ANALOG INTERFACES
HDMI is independent of the various digital television standards used by individual devices, such as ATSC and DVB, as these are encapsulations of compressed MPEG video streams (which can be decoded and output as an uncompressed video stream on HDMI).Because HDMI is a digital interface, it provides the best quality of the video since there are no loss analog to digital conversions as are required for all analog connections (such as component or S-Video).
Also digital video will be sharper than component, and eliminates the softness and ghosting found with component. Small, high contrast details such as text bring this difference out the most. HDMI devices supporting HDCP have the comfort of knowing they will have access to premium HD content now and in the future. Single cable for both video and audio is the most effective format!
5.1. HDMI OVER DVI
5.1.1. What is DVI?
The Digital Visual Interface (DVI) is a video interface standard designed to provide very high visual quality on digital display devices such as LCD computer displays and digital projectors.
The DVI interface uses a digital protocol in which the desired illumination of pixels is transmitted as binary data. When the display is driven at its native resolution, it will read each number and apply that brightness to the appropriate pixel. In this way, each pixel in the output buffer of the source device corresponds directly to one pixel in the display device, whereas with an analog signal the appearance of each pixel may be affected by its adjacent pixels as well as by electrical noise and other forms of analog distortion.
The HDMI standard is actually based on DVI. A DVI signal is electrically compatible with an HDMI video signal; no signal conversion is required when an adapter is used, and consequently no loss in video quality occurs.
i. Backwards Compatible:
One of the most important features included with the HDMI standard is the ability for it to be used with DVI connectors. Through the use of an adapter cable, an HDMI plug can be attached to a DVI monitor port for the video signal. This is a very useful feature for those that do purchase a system with an HDMI compliant video output but their television or computer monitor only has a DVI input. It should be noted that this only uses the video portion of the HDMI cable so no audio can be used with it. In addition, while a monitor with a DVI connector can connect to a HDMI graphics port on the computer, a HDMI monitor cannot connect to a DVI graphics port on the computer unless DVI device supports HDCP.
DVI typically carries no audio data in its TMDS channel. With most home computers using at least one and possible up to three mini-jack cables to run audio from it to the speakers, the HDMI cable simplifies the number of cables require to carry the audio signal to the speakers.
ii. Smaller Standardized Connectors :
One of the big advantages of the HDMI interface over the DVI interface is the size of the connector. From an aesthetic viewpoint, HDMI connectors are less bulky than DVI ones. Also HDMI cables can be made longer than DVI-HDMI can go up to 15m in length.
iii. Increased Color Depth:
Analog and digital color for PC computers has long been restricted to 24-bit color producing roughly 16.7 million colors. DVI is limited to this 24-bit color depth. Early HDMI versions are also limited to this 24-bit color, but the newer 1.3 version allows colors depths of 30, 36 and even 48-bit color depths. This greatly increases the overall quality of the color that can be displayed, but both the graphics adapter and monitor must support the newer HDMI version 1.3.
iv. High-bandwidth Digital Content Protection (HDCP), Consumer Electronics Control (CEC).
v. Support for YUV Color Space andCEA-861B Info Frames.
HDMI CONNECTORS AND CABLES
6.1. HDMI CONNECTORS
Type A
Nineteen pins, with bandwidth to support all SDTV (Standard-definition television), EDTV (Enhanced-definition television) and HDTV modes. The plug (male) connector outside dimensions are 13.9 mm × 4.45 mm and the receptacle (female) connector inside dimensions are 14 mm × 4.55 mm. Type A is electrically compatible with single-link DVI-D.
Type B
This connector (21.2 mm × 4.45 mm) has 29 pins and can carry double the video bandwidth of type A, for use with very high-resolution future displays such as WQUXGA (3840×2400). Type B is electrically compatible with dual-link DVI-D, but has not yet been used in any products.
Type C
A Mini connector defined in the HDMI 1.3 specification, it is intended for portable devices. It is smaller than the type A plug connector (10.42 mm × 2.42 mm) but has the same 19-pin configuration. The differences are that all positive signals of the differential pairs are swapped with their corresponding shield. The type C Mini connector can be connected to a type A connector using a type A-to-type C cable.
Type D
A Micro connector defined in the HDMI 1.4 specification keeps the standard 19 pins of types A and C but shrinks the connector size to something resembling a micro-USB connector. The type D connector is 2.8 mm × 6.4 mm, whereas the type C connector is 2.42 mm × 10.42 mm; for comparison, a micro-USB connector is 2.94 mm × 7.8 mm and USB a is 11.5 mm × 4.5 mm.
Type E
Automotive Connection System defined in HDMI 1.4 specification.
6.2 HDMI CABLES
Although no maximum length for a HDMI cable is specified, signal attenuation (dependent on the cable's construction quality and conducting materials) limits usable lengths in practice. HDMI 1.3 defines two cable categories: Category 1-certified cables, which have been tested at 74.5 MHz (which would include resolutions such as 720p60 and 1080i60), and Category 2-certified cables, which have been tested at 340 MHz (which would include resolutions such as 1080p60 and 2160p30). Category 1 HDMI cables are to be marketed as "Standard" and Category 2 HDMI cables as "High Speed". A cable of about 5 meters (16 ft.) can be manufactured to Category 1 specifications easily and inexpensively by using 28 AWG (0.081 mm²) conductors. With better quality construction and materials, including 24 AWG (0.205 mm²) conductors, a HDMI cable can reach lengths of up to 15 meters (49 ft.). Many HDMI cables under 5 meters of length that were made before the HDMI 1.3 specification can work as Category 2 cables, but only Category 2-tested cables are guaranteed to work.
As of the HDMI 1.4 specification, there are the following cable types defined for HDMI in general:
· Standard HDMI Cable - up to 1080i and 720p
· Standard HDMI Cable with Ethernet
· Automotive HDMI Cable
· High Speed HDMI Cable - 1080p, 4K, 3D and Deep Color
· High Speed HDMI Cable with Ethernet
6.3 EXTENDERS
An HDMI extender is a single device (or pair of devices) powered with an external power source or with the 5V DC from the HDMI source. Long cables can cause instability of HDCP and blinking on the screen, due to the weakened DDC signal that 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. Several companies offer amplifiers, equalizers, and repeaters that can string several standard HDMI cables together. Active HDMI cables use electronics within the cable to boost the signal and allow for HDMI cables of up to 30 meters (98 ft.). HDMI extenders that are based on dual Category 5/Category 6 cable can extend HDMI to 250 meters (820 ft.), while HDMI extenders based on optical fiber can extend HDMI to 300 meters (980 ft.).
FEATURES OF HDMI
7.1. HDCP - HIGH-BANDWIDTH DIGITAL CONTENT PROTECTION
One of the big requirements for the high definition DVD and TV signals is a digital rights management signal. This allows the rights holder to ensure that a digital copy of the material cannot be capture before it reaches the video display.
HDCP is a form of digital copy protection developed by Intel Corporation to prevent copying of digital audio and video content as it travels across Display Port, Digital Visual Interface (DVI), High-Definition Multimedia Interface (HDMI), Gigabit Video Interface (GVIF), or Unified Display Interface (UDI) connections by encrypting the digital content being sent from the source to the receivers.
· The source and receivers initiate a "handshake" and validate that each device is an authorized one.
· Handshaking is making sure that all of your HDMI devices can recognize each other.
· Exchanges a special key called a Key Selection Vector or KSV.
· XOR operation is applied to encrypt each decoded pixel with a 24-bit number.
HDCP uses three systems:
i. Authentication prevents non-licensed devices from receiving content.
ii. Encryption of the data sent over Display Port, DVI, HDMI, GVIF, or UDI interfaces prevents eavesdropping of information and man-in-the-middle attacks.
iii. Key revocation prevents devices that have been compromised and cloned from receiving data.
The DVI video standard did not require that the HDCP or high definition copy protection signal be supported by the devices. As a result, many PC computers and monitors that feature the DVI connector may be locked out from the high definition content. Some video card and display manufacturers do support the HDCP signal with the DVI devices, but it can be hard to ensure that your hardware is compliant.
HDMI has this HDCP built into the standard. As a result, any HDMI capable graphics card and monitor must have this feature. This prevents the potential problem in the future of restricted or non-functional digital video from the PC.
HDCP devices are generally divided into three categories:
Source: The source sends the content to be displayed. Examples include set-top boxes, DVD and Blu-Ray players, and computer video cards. A source has only an HDCP/HDMI transmitter.
Sink: The sink renders the content for display so it can be viewed. Examples include TVs and digital projectors. A sink has one or more HDCP/HDMI receiver.
Repeater: A repeater accepts content, decrypts it, then re-encrypts and retransmits the data. It may perform some signal processing, such as up-converting video into a higher-resolution format, or splitting out the audio portion of the signal. Repeaters have both HDMI inputs and outputs an example would be an AV receiver. Examples include home theater audio-visual receivers that separate and amplify the audio signal, while re-transmitting the video for display on a TV. A repeater could also simply send the input data stream to multiple outputs for simultaneous display on several screens.
7.2. HIGHER SPEED
HDMI 1.3 increases its single-link bandwidth from 165 MHz (4.95 Gbps) to 340 MHz (10.2 Gbps) to support the demands of future high definition display devices:
· Deep Color - increasing the color depth from millions to billions of colors
· Higher resolutions - over 400% greater resolution than 720p HDTV
· High frame rates - higher refresh rates (up to 120 Hz) for smoother motion
7.3 DEEP COLOR
HDMI 1.3 supports 30-bit, 36-bit and 48-bit (RGB or YCbCr) color depths, up from the 24-bit depths in previous versions of the HDMI specification.
· Let HDTVs and other displays go from millions of colors to billions of colors.
· So, for example, a TV that accepts the 24 or 12-bit form can mix together any one of 4,096 shades (levels of brightness) of each primary color for 68.7 billion possible colors.
4,096 red x 4,096 green x 4,096 blue = 68,719,476,736 colors!!
· Eliminates on-screen color banding, for smooth tonal transitions and subtle gradations between colors.
· Enables increased contrast ratio for sharper images & greater detail.
· Deep Color increases the number of bits available for transmission for each channel.
· Can represent many times more shades of gray between black and white. At 30-bit.
· Pixel depth, four times more shades of gray would be the minimum, and the typical improvement would be eight times or more.
· Eliminates artifacts that appear as bands or contours.
· Most noticeable in subtle gradations and tonal Transitions.
· More accurately represents original material.
· Deeper color palette produces video more like original film.
· Live events look more natural.
7.4 BROADER COLOR SPACE
HDMI 1.3 removes virtually all limits on color selection. The human eye can see a broad range of color. Standard RGB color space allows the display of a portion of the colors that are viewable to the human eye (see triangle in Figure 2). The next generation “xvYCC” color space can display virtually the entire gamut of colors viewable by the human eye (Figure 3).
· Next-generation “xvYCC” color space supports 1.8 times as many colors as existing HDTV signals.
· Les HDTVs display colors more accurately.
· Enables displays with more natural and vivid colors.
xvYCC was motivated by the fact that modern display and capture technologies often have underlying RGB primaries with significantly higher saturation than the traditional CRT displays, allowing them to handle a wider color gamut. But these devices have been unable to do this without upsetting basic calibration, as all existing video storage and transmission systems are based on CRT primaries, and are hence limited to the CRT gamut.
7.5 NEW MINI CONNECTOR
With small portable devices such as HD camcorders and still cameras demanding seamless connectivity to HDTVs, HDMI 1.3 offers a new, smaller form factor connector option.
7.6 LIP SYNC
Because consumer electronics devices are using increasingly complex digital signal processing to enhance the clarity and detail of the content, synchronization of video and audio in user devices has become a greater challenge and could potentially require complex end-user adjustments. HDMI 1.3 incorporates automatic audio synching capabilities that allow devices to perform this synchronization automatically with total accuracy.
7.7 NEW HD LOSSLESS AUDIO FORMATS
In addition to HDMI’s current ability to support high-bandwidth uncompressed digital audio and all currently-available compressed formats (such as Dolby® Digital and DTS®), HDMI 1.3 adds additional support for new lossless compressed digital audio formats Dolby True HD and DTS-HD Master Audio™.
7.8 HOT PLUG DETECT
The sink device (display unit) can indicate its presence to a source with a hot plug detect signal to identify when a cable has been connected and to start authentication.
HDMI VERSIONS
There are five main versions that most equipment will correspond to — 1.0, 1.1, 1.2, 1.3 and 1.4.
Notice that the versions signify changes to the types of audio they can transmit, as all versions should be able to transmit HD video up to 1080p.
8.1 HDMI 1.0
HDMI 1.0 combines a digital video signal (standard or high-definition) with a two-channel audio signal over a single cable, such as between an HDMI-equipped DVD player and Television. HDMI 1.0 was released December 9, 2002 and is a single-cable digital audio/video connector interface with a maximum TMDS bandwidth of 4.9 Gbit/s. It supports up to 3.96 Gbit/s of video bandwidth (1080p/60 Hz or UXGA) and 8 channel LPCM/192 kHz/24-bit audio.
8.2 HDMI 1.1
This version adds the ability to transfer not only video and two-channel audio over a single cable, but also added the ability to transfer Dolby Digital, DTS, and DVD-Audio surround signals, as well up to 7.1 channels of PCM audio. HDMI 1.1 was released on May 20, 2004.
8.3 HDMI 1.2
This version of HDMI adds the ability to transfer SACD signals in digital form from a player to a receiver. HDMI 1.2 was released August 8, 2005 and added support for One Bit Audio, used on Super Audio CDs, at up to 8 channels. It also added the availability of HDMI type A connectors for PC sources, the ability for PC sources to only support the sRGB color space while retaining the option to support the YCbCr color space, and required HDMI 1.2 and later displays to support low-voltage sources.
8.4 HDMI 1.3
This version includes improvements in both audio and video capability. With the advent of Blu-ray Disc and HD-DVD, version 1.3 adds the ability to transfer the digital bit streams for the new high resolution audio formats: Dolby Digital Plus, Dolby True HD, and DTS-HD.HDMI 1.3 was released June 22, 2006 and increased the single-link bandwidth to 340 MHz (10.2 Gbit/s).It 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. It also optionally supports output of Dolby True HD and DTS-HD Master Audio streams for external decoding by AV receivers. It incorporates automatic audio syncing (audio video sync) capability. It defined cable Categories 1 and 2, with Category 1 cable being tested up to 74.25 MHz and Category 2 being tested up to 340MHz. It also added the new type C Mini connector for portable devices.
8.5 HDMI 1.3a
In addition to the above audio improvements, HDMI 1.3 and 1.3a increase the amount of video bandwidth that can be transferred from a source to a display. This means, that in addition to the standard 24-bit color depth we are used to, HDMI 1.3 and 1.3a have the ability to transfer color depths up to 48-bits, and can accommodate resolutions much higher than the 1080p resolution standard that is in use today.HDMI 1.3a was released on November 10, 2006 and had Cable and Sink modifications for type C, source termination recommendations, and removed undershoot and maximum rise/fall time limits. It also changed CEC capacitance limits, clarified sRGB video quantization range, and CEC commands for timer control were brought back in an altered form, with audio control commands added. It also added support for optionally streaming SACD in its bit stream DST format rather than uncompressed raw DSD like from HDMI 1.2 onwards.
HDMI 1.3b, 1.3b1 and 1.3c were released on March 26, 2007, November 9, 2007, and August 25, 2008 respectively. They do not introduce differences on HDMI features, functions, or performance, but only describe testing for products based on the HDMI 1.3a specification regarding HDMI compliance (1.3b), the HDMI type C Mini connector (1.3b1), and active HDMI cables (1.3c).
8.6 HDMI 1.4
HDMI 1.4 was released on May 28, 2009, and the first HDMI 1.4 products were available in the second half of 2009. HDMI 1.4 increases the maximum resolution to 4K × 2K (3840×2160p at 24 Hz/25 Hz/30 Hz and 4096×2160p at 24 Hz, which is a resolution used with digital theaters, expanded support for color spaces, with the addition of sYCC601, Adobe RGB and Adobe YCC601; and an Automotive Connection System. HDMI 1.4 supports several stereoscopic 3D formats including field alternative (interlaced), frame packing (a full resolution top-bottom format), line alternative full, side-by-side half, side-by-side full, 2D + depth, and 2D + depth + graphics + graphics depth (WOWvx), with additional top/bottom formats added in version 1.4a .
HDMI 1.4 requires that 3D displays support the frame packing 3D format at either 720p50 and 1080p24 or 720p60 and 1080p24. High Speed HDMI 1.3 cables can support all HDMI 1.4 features except for the HDMI Ethernet Channel.
HDMI 1.4a was released on March 4, 2010 and adds two additional mandatory 3D formats for broadcast content, which was deferred with HDMI 1.4 in order to see the direction of the 3D broadcast market. HDMI 1.4a has defined mandatory 3D formats for broadcast, game, and movie content. HDMI 1.4a requires that 3D displays support the frame packing 3D format at either 720p50 and 1080p24 or 720p60 and 1080p24, side-by-side horizontal at either 1080i50 or 1080i60, and top-and-bottom at either 720p50 and 1080p24 or 720p60 and 1080p24.
HDMI version 1.4 adds practical enhancements for HDMI connectivity. If home theater components, such as HDTVs, Blu-ray Disc players, and Home Theater Receivers, are HDMI 1.4 enabled, one or more of the following features can be implemented:
HDMI Ethernet Channel: This adds internet and home network connectivity to HDMI. In other words, both Ethernet and HDMI functions are available within a single cable connection.
· Audio Return Channel: This may be the most practical application of HDMI 1.4. What this feature provides is a single HDMI connection between a TV and a home theater receiver that can not only pass audio/video signals from the receiver to the TV, but also pass audio originating from the TV's tuner to the receiver. In other words, when listening to audio accessed by the TV's tuner, you don't need a separate audio connection going from the TV to the home theater receiver.
· 3D Over HDMI: HDMI 1.4 is designed to accommodate 3D Blu-ray Disc standards, with the capacity of passing two simultaneous 1080p signals using one connection. NOTE: An update (HDMI 1.4a) also incorporates additional 3D TV Broadcast, Cable, and Satellite formats.
· 4Kx2K Resolution Support: Although the current high definition standard for consumer equipment tops out at 1920x1080 (1080p), HDMI 1.4 can accommodate future 3840x2160 and 4096x2160 high definition pixel resolutions now in the planning stages.
· Expanded Support for Color Spaces: This allows better color reproduction when displaying digital still photos from HDMI-connected Digital Still Cameras.
· Micro HDMI Connector: Just as mini-USB is employed with portable digital devices, a new "Micro HDMI" Connector is much smaller connector that can still supports up to 1080p resolutions for portable devices. This is very practical for video camcorders, digital still cameras, and portable digital video playback devices.
· Automotive Connection System: With the increase of in-car digital audio/video devices, HDMI 1.4 can handle the more demanding vibration, heat, and noise that may affect the quality of audio and video reproduction.
HDMI version | 1.0–1.2a | 1.3 | 1.4 |
Date initially released | December 29, 2002 | June 22, 2006 | May 28, 2009 |
Maximum clock rate (MHz) | 165 | 340 | 340 |
Maximum TMDS throughput per channel (Gbit/s) including 8b/10b overhead | 1.65 | 3.40 | 3.40 |
Maximum total TMDS throughput (Gbit/s) including 8b/10b overhead | 4.95 | 10.2 | 10.2 |
Maximum throughput (Gbit/s) with 8b/10b overhead removed | 3.96 | 8.16 | 8.16 |
Maximum audio throughput (Mbit/s) | 36.86 | 36.86 | 36.86 |
Maximum color depth (bit/px.) | 24 | 48 | 48 |
Maximum resolution over single link at 24-bit/px | 1920×1200p60 | 2560×1600p75 | 4096×2160p24 |
Maximum resolution over single link at 30-bit/px | N/A | 2560×1600p60 | 4096×2160p24 |
Maximum resolution over single link at 36-bit/px | N/A | 1920×1200p75 | 4096×2160p24 |
N/A | 1920×1200p60 | 1920×1200p60 |
Table 8.1: HDMI version comparison - 1
HDMI version | 1.0 | 1.1 | 1.2 1.2a | 1.3 | 1.3a 1.3b 1.3b1 1.3c | 1.4 | 1.4a |
sRGB | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
YCbCr | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
8 channel LPCM, 192 kHz, 24 bit audio capability | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Blu-ray Disc and HD DVD video and audio at full resolution | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Consumer Electronic Control (CEC) | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
DVD-Audio support | No | Yes | Yes | Yes | Yes | Yes | Yes |
Super Audio CD (DSD) support | No | No | Yes | Yes | Yes | Yes | Yes |
Deep Color | No | No | No | Yes | Yes | Yes | Yes |
xvYCC | No | No | No | Yes | Yes | Yes | Yes |
Auto lip-sync | No | No | No | Yes | Yes | Yes | Yes |
Dolby True HD bit stream capable | No | No | No | Yes | Yes | Yes | Yes |
DTS-HD Master Audio bit stream capable | No | No | No | Yes | Yes | Yes | Yes |
Updated list of CEC commands | No | No | No | Yes | Yes | Yes | Yes |
Ethernet channel | No | No | No | No | No | Yes | Yes |
Audio return channel | No | No | No | No | No | Yes | Yes |
4k × 2k Resolution Support | No | No | No | No | No | Yes | Yes |
3D over HDMI | No | No | No | No | No | Yes | Yes |
3D over HDMI 1080p60 | No | No | No | No | No | No | Yes |
Table 8.2: HDMI version comparison - 2
ADVANTAGES AND DRAWBACKS OF HDMI
9.1. ADVANTAGES
9.1.1. Convergence
HDMI is the interface for convergence of PC and consumer electronics devices: HDMI enables PCs to deliver premium media content including high definition movies and multi-channel audio formats. HDMI is the only interface enabling connections to both HDTVs and digital PC monitors implementing the DVI and HDMI standards.
9.1.2 Simplicity
· Transmits all formats of digital audio and video through a single cable, replacing as many as thirteen older cables and eliminating clutter.
· Makes it simple to hook up other devices to your home theater system. PCs, gaming consoles, and video cameras can all be connected with the same one-plug convenience.
· Makes it easy to install or upgrade an all-digital home entertainment system. All HDMI versions are backward-compatible with previous versions.
· HDMI combines video and multi-channel audio into a single cable, eliminating the cost, complexity, and confusion of multiple cables currently used in A/V systems. This is particularly beneficial when equipment is being upgraded or added.
9.1.3 Performance
· Enormous bandwidth capacity – up to 10.2 gigabits per second, more than twice the bandwidth needed to transmit an uncompressed 1080p signal.
· Better looking movies
· Faster gaming
· Richer audio
· Future-ready for emerging technologies.
· 3D movies and gaming
· Higher resolutions, like 1440p or Quad HD
· Faster refresh rates, like 120Hz.
· Deep Color, taking the HDTV palette from millions to trillions of colors.
9.1.4 Intelligence
· HDMI is a "smart" two-way connection that allows devices to communicate and interact with each other to dramatically improve your home theater experience.
· Devices connected with HDMI have the ability to scan each other’s capabilities and automatically configure certain settings. An HDTV and a DVD player, for example, can auto-negotiate settings like resolution and aspect ratio to correctly match the format of the incoming content to the highest capabilities of the TV.
· Enabling new functionality such as automatic configuration and one-touch play. By using HDMI, devices automatically deliver the most effective format (e.g. 480p vs. 720p, 16:9 vs. 4:3) for the display that it is connected to - eliminating the need for the consumer to scroll through all the format options to guess what looks best.
9.1.5 Quality
Because HDMI is a digital interface, it provides the best quality of the video since there are no lossy analog to digital conversions as are required for all analog connections (such as component or S-video). The difference is especially noticeable at higher resolutions such as 1080p. Digital video will be sharper than component, and eliminates the softness and ghosting found with component. Small, high contrast details such as text bring this difference out the most.
9.1.6 HD Content-Ready
HDMI devices supporting HDCP have the comfort of knowing they will have access to premium HD content now and in the future. HD-DVD and Blu-ray have delayed the activation of the image constraint token (a.k.a. content protection flag) with today’s HD movies to help minimize potential issues caused by the transition, but are expected to activate this in a few years, meaning future HD movies will then not be viewable at HD resolutions over unprotected interfaces such as analog component.
9.1.7 Consumer Electronics Control
CEC provides for integrated, "one-touch" commands across multiple linked components. When enabled by the manufacturer, CEC allows system-wide behaviors like one-touch play or one-touch record, where pressing a single button on your remote launches a series of coordinated commands.
9.2 PROBLEMS WITH HDMI
9.2.1 Distance Limitations
Maximum distance for HDMI Cat1 cables is up to 35 meters (approx.) for full capacity and maximum distance for HDMI Cat2 cables is up to 10 meters (approx.) for full capacity. Beyond this limit, they need extenders. There are extenders like UTP cable extenders for HDMI, HDMI cable extenders, Fiber extenders for HDMI and Coaxial extenders for HDMI. Even Switches, Distribution amplifiers, audio/video processors act as repeaters. But extending HDMI cables this way has its limitations.
9.2.2 Switching Delays
Sometimes, blank screens can be caused due to authentication delays. There can also be screen flashing errors.
9.2.3 Field Termination
There are limitations to field terminations of HDMI cables. They cannot be easily terminated in the field like their analog counterparts.
9.2.4 Costly
HDMI cables are more expensive (per meter) than their analog counterparts.
9.2.5 Multiple locations
They are difficult to run in multiple applications spanning various locations. There are more complexities in such situations than just the distance limitations.
9.2.6 EDID
One such complexity is with EDID (Extended Display Identification Data) which is used in automatic identification of resolutions and audio formats. Both HDMI and EDID specifications offer limited guidance in multiple location deployment scenarios.
9.2.7 CEC
The Consumer Electronic Format which enables the different devices to talk to each other becomes a problem when there is a central control system to control all the connected audio/video devices. It causes confusion when the devices themselves change their configuration as they might get undetected by the control systems.
9.2.8 Multi-Channel Audio
While HDMI sources can transmit multi-channel audio sources, they cannot transmit multi-channel and standard two channel stereo signals at the same time (simultaneously). This becomes a problem with multi-room installations that has various devices supporting different audio formats.
9.2.9 DVI Compatibility
HDMI devices are compatible with DVI interfaces but require a separate audio cable as DVI carries only video signals. It also needs a HDMI-DVI connector in such scenarios.
9.2.10 Damage prone connectors
HDMI connects like a USB device for PCs, while DVI still has screw pins on its connector. However, this means that HDMI connections are more prone to damage from accidental knocks so more care needs to be taken with them. Tripping over a cable plugged into an HDMI port can easily damage the port.
9.2.11 HDCP
HDCP can cause problems for users who want to connect multiple screens to a device; for example, a bar with several televisions connected to one satellite receiver. HDCP devices can create multiple keys, allowing each screen to operate, but the number varies from device to device; e.g., a Dish or Sky satellite receiver can generate 16 keys. The technology sometimes causes handshaking problems where devices cannot establish a connection, especially with older high-definition displays.
FURTHER DEVELOPMENTS
HDMI technology is the global standard for connecting high-definition products: the uncompressed, all-digital interface that delivers both dazzling quality and unmatched ease of use. Over 1,000 manufacturers now incorporate HDMI connectivity into a growing list of consumer products:
- HDTVs
- Blu-ray Disc players
- multimedia PCs
- gaming systems
- digital cameras and camcorders
- mobile devices and more.
- The HDMI Founders are Hitachi, Matsushita Electric Industrial (Panasonic/National/Quasar), Philips, Silicon Image, Sony, Thomson (RCA), and Toshiba. Digital Content Protection, LLC provides HDCP (which was developed by Intel) for HDMI.
- Get appreciation and support from various industries like Hollywood Studios (Fox, Universal, Warner Bros, and Disney), Cable operators (DirecTV, EchoStar (Dish Network) and Cable Labs) and Satellite operators.
- Being used in the HDTV, Camcorders and Digital Still Cameras since 2006.
- Shipments of HDMI exceeded that of DVI in 2008.
- In 2008, PC Magazine awarded a Technical Excellence Award in the Home Theater category for an "innovation that has changed the world" to the CEC portion of the HDMI specification.
10.1 OPPORTUNITIES
- HDMI for 3D.
- Growing with the advancements in high definition programming and DVDs.
- Video games and personal computers also integrating HDMI.
- Commercial businesses also opting for HDMI.
- Demand for HDMI to increase at the rate of 23% by the year 2012.
CONCLUSION
HDMI technology is the global standard for connecting high-definition products: the uncompressed, all-digital interface that delivers both dazzling quality and unmatched ease of use. HDMI (High-Definition Multimedia Interface) is a compact audio/video interface for transmitting uncompressed digital data. It's a single cable and user-friendly connector that replaces the maze of cabling behind the home entertainment center.
HDMI connects digital audio/video sources—such as set-top boxes, Blu-ray Disc players, personal computers (PCs). HDMI (High-Definition Multimedia Interface) is today the best kind of digital audio and video connector available that promises to replace all connectors currently used by players, cable/satellite decoders, TV sets, video projectors and video monitors
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