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|HDTV Terms - What do they mean?|
An HD presentation format consisting of 1,080 vertical lines of display resolution in an interlaced scan. Most HD programming in the U.S. (terrestrial & satellite) is transmitted in the 1080i format.
An HD presentation format consisting of 1,080 vertical lines of display resolution in a progressive scan. While a growing number of HDTV monitors are capable of displaying 1080p content, 1080p sources are relatively limited.
An HD presentation format consisting of 1,440 vertical lines of display resolution in a progressive scan. Currently, this level of resolution is limited to PC applications (i.e. QXGA displays), but future generations of HDTVs may feature 1440p capability.
A non-HD presentation format consisting of 480 vertical lines of display resolution in an interlaced scan. Terrestrial and satellite TV providers – analog and digital – still transmit the majority of their programming in 480i format.
A non-HD presentation format consisting of 480 vertical lines of display resolution in a progressive scan. Progressive-scan DVD players typically output a 480p signal.
An HD presentation format consisting of 720 vertical lines of display resolution in a progressive scan. A limited amount of HD programming in the U.S. (terrestrial & satellite) is transmitted in 720p format.
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The digital audio format used for DTV broadcasts in the United States.
Analog systems represent data as a series of variations in some measurable, physical quantity, such as voltage or waveform. (See also Digital)
The ratio of screen width to screen height. For television monitors it is either 4:3 (“standard”) or 16:9 (“widescreen”). NTSC analog TV systems use a 4:3 aspect ratio, while ATSC uses the wider 16:9 aspect ratio. Movie theaters use a number of different aspect ratios, some even wider than 16:9.
Authorized Testing Center. In order to verify compliance with the HDMI technical specification, components are tested in ATCs operated by HDMI Licensing, LLC. Products are tested according to a Compliance Test Specification (CTS). ATCs are located in Europe, Asia, and North America.
Advanced Television System Committee technical standard. The digital replacement for the legacy NTSC broadcast standard.
The carrying capacity of a data interconnect. High-bandwidth connections are also called high-speed connections, because they can transmit large quantities of data very quickly. HDMI has extremely high bandwidth capacity: up to 10.2 gigabits per second.
See Color Depth.
One of two potential successor technologies to the DVD, using multi-layer disc technology and a blue laser to deliver feature-length movies in HD resolution HDMI is the interconnect standard for Blu-ray Disc players. (See also HD-DVD).
A technology used in many HDMI receiver chips to boost the incoming signal, allowing the sink device (TV, projector, monitor, etc.) to compensate for weaker signals. Components employing cable equalization technology can be connected with longer cable runs than might otherwise be practical.
Category 5 and Category 6 cabling is used in Ethernet and Fast Ethernet networks, and has also been adapted to transmit an HDMI signal. Both cables feature four twisted-pair copper wires and an RJ-45 connector, with the main difference being that CAT-6 has tighter tolerances for line noise and crosstalk. CAT-5/CAT-6 has been successfully used to transmit HDMI over extremely long cable runs, i.e. 40-50 meters.
Category 1 HDMI Cable
See Standard HDMI Cable
Category 2 HDMI Cable
See High Speed HDMI Cable
See Consumer Electronics Control.
A program used for encoding and decoding a digital signal, usually employing compression/decompression algorithms to streamline the data and conserve bandwidth.
A symptom of insufficient color depth, color banding occurs when a monitor is unable to render smooth color gradients, and instead presents stripes or bands of color, especially in very light or very dark areas of an image. This occurs because the human eye is extraordinarily sensitive to color gradations, and can detect the change from one shade to another when color depth is limited.
A measurement of the number of bits used to represent the color of a single pixel. Greater color depth gives a larger number of distinct colors, i.e. millions or billions of colors, allowing for smoother color gradients. (See also: Deep Color)
See Color Banding.
Compliance Testing Specification (CTS)
Manufacturers who license HDMI technology are required to put their products through a formal testing process defined in the HDMI CTS. Compliance testing under the CTS includes both manufacturer self-testing and submission of products to an Authorized Testing Center, or ATC.
A legacy video connection for home theater equipment, using three separate cables to send a picture in three discrete color channels, e.g. red, green, and blue.
Technologies designed to increase the carrying capacity of a data connection by compacting the data stream at one end and re-expanding it at the other end. With the exception of lossless audio codecs, compression and decompression algorithms for audio and video are inherently “lossy,” meaning that data are lost in the process. One of the advantages of HDMI over other connection technologies is its enormous carrying capacity, which makes compression unnecessary.
Consumer Electronics Control (CEC)
One of the channels in an HDMI connection is dedicated to a set of advanced control functions, collectively known as CEC. When enabled by the manufacturer, CEC functionality allows connected devices to control each other in useful ways. For instance, a single command on a remote control can be used to play a DVD, or to launch other complex activities across multiple devices in a home theater system.
See Compliance Testing Specification.
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The Display Data Channel, one of the channels in an HDMI connection. DDC allows devices to assess each others’ capabilities and adjust themselves accordingly. For example, a DVD player can discover the maximum resolution of the monitor it’s connected to by reading the monitor’s EDID ROM chip, and optimize its signal output to match that monitor’s display capabilities.
The expanded bandwidth of HDMI 1.3 is allowing manufacturers to design displays with much greater Color Depth. These new “Deep Color” monitors will be capable of rendering many more distinct hues than current displays – up to trillions of colors rather than thousands or millions. (See also: Color Depth; Color Banding)
Digital systems represent data in binary form, encoding it as a series of zeroes and ones. (See also: Analog)
A family of multi-channel audio codecs from Dolby Laboratories, based on AC-3 technology, that includes Dolby Digital, Dolby Digital EX, Dolby Digital Live, Dolby Digital Surround EX, and Dolby Digital Plus.
An advanced audio codec developed by Dolby Laboratories. Dolby TrueHD is a lossless audio format, meaning that no audio information is lost when the signal is compressed and uncompressed.
Direct-Stream Digital, the trademark name used by Sony and Philips for the audio encoding technology used in the Super Audio CD (SACD). Also known as One-bit audio.
A family of multi-channel audio codecs from Digital Theater Systems, Inc., including DTS, DTS-ES, DTS Neo:6, and DTS 96/24. DTS audio codecs are used in both commercial and home theater applications.
DTS-HD Master Audio
An advanced audio codec developed by Digital Theater Systems. DTS-HD Master Audio is a lossless audio format, meaning that no audio information is lost when the signal is compressed and uncompressed.
Digital televisions, the successor technology to analog TV, are televisions capable of receiveing a ditigal terrestrial or cable broadcast signal, like ATSC (North America) or
Digital Visual Interface, a predecessor technology to HDMI. There are different versions of DVI for PC and CE applications – DVI-D is the version used in CE devices. DVI is based on the same technology as HDMI, so the two connections are completely compatible – however a separate set of connections is required to transmit the audio signal, since DVI transmits video only.
A memory chip (ROM), included in most HD devices, containing essential information about that device. When connected via HDMI, EDID data is shared so that other components can read its make, model, and capabilities through the DSD channel. EDID stands for Extended Display Identification Data, and is defined by VESA, a video standards organization.
A widescreen television capable of displaying a 480p signal.
Extended Color Gamut
See Refresh Rate.
High definition. Usually used to describe any device capable of generating or displaying a signal with a resolution of at least 720 vertical lines (i.e. 720p). Another accepted definition is any signal containing at least one million pixels of video data in a single frame (vertical resolution x horizontal resolution).
High-bandwidth Digital Content Protection. Developed by Intel, HDCP is an authentication system designed to protect copyrighted audiovisual content. Most HDMI-enabled and DVI-enabled devices also employ HDCP.
High-definition DVD, one of two potential successor technologies to the DVD. A high-density optical disc format designed for the storage of high-definition video. HDMI is the interconnect standard for HD-DVD players (see also: Blu-ray Disc)
High Definition Multimedia Interface. A 19-pin digital connection that transmits both high-definition uncompressed video and multi-channel audio through a single cable. HDMI is the preferred connection for HD devices.
The HDMI technical specification is updated from time to time, and HDMI 1.3 is the most recent release. While all versions of the spec are backward-compatible, devices built to the 1.3 standard may feature extended capabilities not found in earlier devices. For instance, a newer AV receiver might take advantage of HDMI 1.3’s native support for the new lossless audio codecs, but it would still be fully compatible with older devices built under earlier versions of HDMI.
A device that both receives and sends HDMI signals, such as an AV receiver. A/V receivers are considered HDMI repeaters.
A device that receives an HDMI signal, such as an HDTV.
A device that sends an HDMI signal, such as a DVD player or Set-top box.
High Definition Television. A widescreen television capable of displaying a 720p signal or better.
High Speed HDMI Cable
High Speed HDMI cables are tested to a more rigorous performance standard, aimed at meeting the needs of high-end home theater systems. It is performance tested to 340 MHz, and can reliably transmit a 1080p signal (and more) up to 7.5 meters. High Speed HDMI Cables are referred to as Category 2 cables in the HDMI specification. (See also: Standard HDMI Cable).
In an interlaced scan, only half the screen is refreshed at a time. The video signal beam skips every other line, and fills in the missing lines on the next pass. (See also: Progressive Scan)
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One of the new features enabled in HDMI 1.3, Lip Sync functionality enables the automatic synchronization of video and audio signals, correcting for processor lags that can force audio and video timing out of proper alignment.
The latest multi-channel audio codecs are based on lossless compression algorithms with extremely high fidelity, such as Dolby TrueHD and DTS-HD Master Audio.
Mini HDMI Connector
A miniature HDMI connector, introduced in HDMI 1.3, designed for use in mobile and handheld products where space is at a premium. The Mini HDMI Connector is pin-for-pin compatible with the larger Standard HDMI Connector and completely compatible as well. The Mini HDMI Connector is referred to as the Type C Connector in the HDMI specification. See also Standard HDMI Connector.
A family of audio/video codecs developed by the Motion Picture Experts Group. The majority of TV content – cable, broadcast, and satellite – is currently transmitted in the MPEG-2 format. HD-DVD and Blu-ray Disc players, along with some recently launched satellites, rely on the newer and more powerful MPEG-4 format.
The legacy analog television broadcast system used in the US, being replaced by the ATSC digital system.
A digital audio signal created by sampling an analog signal and expressing it in binary form. All versions of HDMI include the capacity to transmit eight channels of uncompressed, 192 kHz PCM audio.
See Color Depth.
In a progressive scan, the entire screen is refreshed on every pass. The video signal beam does not skip alternate lines, but fills in each line every time, which tends to render smoother motion sequences. (See also: Interlaced Scan)
The frequency with which a video image is refreshed, expressed as either frames per second (i.e. 60 fps) or as an equivalent frequency (i.e. 60 Hz). Faster refresh rates tend to render smoother motion sequences. Refresh rates for broadcast TV vary by region – for example, European HD systems run at 50 Hz.
See HDMI Repeater
A color model in which red, green, and blue values are used to reproduce a set of standard colors. Many HD monitors use the RGB color model.
Super Audio CD. An optical disc format for high-fidelity audio, using one-bit (DSD) audio encoding, developed by Sony and Philips Electronics as a replacement for the audio CD. Compared to the conventional CD, SACD boosts frequency response from 20kHz to 100kHz, and dynamic range from 96 to 120 db. Classical and jazz titles tend to dominate the SACD catalog.
An analog connection standard, also known as Euroconnector or Peritel. SCART is a 21-pin connector used in Europe to interconnect satellite receivers, television sets, and other audiovisual equipment. SCART transmits both video and audio data in a single cable. The name comes from « Syndicat des Constructeurs d’Appareils Radiorécepteurs et Téléviseurs. »
Set-top Box (STB)
A device for decoding incoming AV signals, such as programs from a cable or satellite TV network. Many models also include DVR (digital video recorder) technology. Virtually all STBs now rely on HDMI output.
See HDMI Sink.
See HDMI Source.
Standard HDMI Cable
A Standard HDMI cable is one that is tested to performance standards that satisfy the requirements of most consumers. It is performance tested to 74.5 MHz, and can reliably transmit a 1080i or 720p signal up to 15 meters. Standard HDMI Cables are referred to as Category 1 cables in the HDMI specification. (See also: High Speed HDMI Cable) .
Standard HDMI Connector
The 19-pin plug that is currently used in most HDMI-enabled products. The Standard HDMI Connector is referred to as the Type A HDMI Connector in the HDMI specification. See also Mini HDMI Connector.
See Set-top box.
Transition Modulated Differential Signaling, a technology for transmitting serial data at very high speeds. TMDS is a core technology used in both DVI and HDMI.
Type A HDMI Connector
See Standard HDMI Connector.
Type C HDMI Connector
See Mini HDMI Connector.
The Video Electronics Standards Association. The industry group responsible for the EDID standard and other technical specifications.
A new standard for an expanded, “wider” color space or gamut, enabled by HDMI 1.3 and being developed by Sony and Mitsubishi, among others. The xv color space (also known as xvYCC color) incorporates a much larger portion of the visible color spectrum than the older RGB color model.
The original acronym the color model now known as x.v.Color.
A family of color spaces, used in some HD applications, where color is expressed using a luma component plus red and blue chroma components, rather than by describing absolute color values, as in the RGB color model. Also known as YPbPr color.