High definition isn’t just a format to watch movies in, it also comes with its own language to learn. We decipher the terms you’re most likely to come across… Refers to audio systems that have two, five, or seven main speakers surrounding the viewer/listener with an additional subwoofer. So a 5.1 surround-sound system would have three front (left, right and middle) and two rear (left and right), as well as a subwoofer, making it 5.1. An encoding technique that scans the fi lm many times in many ways to reduce the bitrate requirements. Rather than simply scanning once, then using the same bitrate for the entire fi lm, multipass will assess the fi lm in segments. Some scenes will require a lower rate, allowing more space for the more lively scenes. Popular examples of multipass are SuperVCD and DivX. HD displays capable of producing three-dimensional images recently started going on sale in Japan and, while special glasses are currently required, research is being done to get the same effect without additional eyeware. Expect to see 3D-enabled content emerge over the next couple of years. While it may not be a progressive way of thinking, some believe that using the cheaper DVD technology and packing it with 720p resolution and the most advanced compression technology means there’s little need for Blu-ray and HD DVD. Simply meaning 4 units wide by 3 high and 16 units wide by 9 units high respectively, 4:3 and 16:9 are a measurement of picture size. 4:3 is the academy standard, but is soon to be replaced by 16:9. These are the resolutions of both TVs and broadcasting standards available. In Britain, the broadcasting standard has been 480i for some time now, so a large part of going HD is the ability to receive picture quality of the higher resolutions. The ‘i’ stands for ‘interlaced’, meaning that each frame comes in two halves, closely laced together, therefore tricking the eyes into thinking the image is one. The ‘p’ stands for ‘progressive scan’, which is one single image for each picture. 1080p (1,920 x 1,080 pixels) is currently the highest resolution available for your home. This means that the image you view will have been compressed in order to fit into a narrow medium (ie film or video). For the material to be viewed in its full glory it must be expanded back to its original wide format. The removal of noise created when high-resolution images are presented in a lower resolution. It’s essentially a blurring or softening filter that removes the ‘noise’ or artefacts in an outline. An imperfection in the image due to low compression quality or insuffi cient bitrate. Home-cinema decks that receive audio and video data from your source player. The receiver can then decode digital audio and even upscale video before outputting the improved content to your display and surround-speaker system. An encoding method of MPEG-4 that is increasing in popularity. The amount of information that can be transmitted in a given period of time. One HDTV signal takes up the same bandwidth as four standard-definition channels. Blu-ray players with hardware Profile 2.0 will be able to access additional interactive disc content, such as playing networked interactive games or accessing bonus material online. The tool used to produce the menus and interactivity of Blu-ray discs. It offers a huge improvement over the DVD menus, which can include quizzes, extra downloads, games and far more depth and value than DVD. The HD DVD version is called iHD. How much physical space one second of audio/visual information takes up. Denoted in bits, not bytes. Given the nature of plasma and LCD screens, true blacks are difficult to create. Trying to separate the light and avoid it saturating into the darker pixels is a problem. When looking for a TV with good blacks, check out the contrast ratio. The next-generation in disc-based media that stores up to 25GB in a single layer. Currently the most layers available are four, but this is sure to increase. The type of laser used to read Blu-ray Discs. It’s a much shorter wavelength (405nm versus DVD’s 650nm), which allows for huge amounts of data to be stored. The higher numerical aperture (0.85 versus 0.6 for DVD) has raised issues of reliability of Blurays, but we haven’t seen any issues yet. A feature on Blu-ray Discs with hardware Profile 1.1, Blu-Wizard enables you to create movie playlists that combine chapters, featurettes, deleted scenes and other extras. Blu-ray players with hardware Profile 1.1 are able to access disc feaetures such as Picture-in-Picture commentaries and user playlists. A method of producing images. Common for old-style standard-definition TVs. A post-production process that adjusts the colour of an image to create the desired effect. Often used in professional photography. A piece of software that enables you to access fi les in that format, eg MPEG-2. If you need a specifi c codec, these are easy to fi nd by running a search on the internet. Lossy compression removes data from the source to enable lower memory requirements. Successive compressions in this fashion will see the material degrade as each compression sacrifi ces more and more data. Lossless compression takes away less data, which often allows for better quality audio/ visuals. The popular MPEG-4 compression codec is lossy but still manages to maintain high quality with an amazing reduction in space required. The CEC channel is an optional feature of HDMI connectivity that enables users to control various CEC-enabled equipment with one remote, or allow equipment to control other pieces of equipment, such as a DVD player switching a TV on when a disc is inserted. Many manufacturers have alternative names for CEC. One of the largest and most important hardware events. Taking place in January, it’s where most manufacturers choose to announce their wares. Notable past announcements include Xbox 360, Commodore 64 and Laserdisc. The difference between the blackest black and the whitest white the display can produce. High contrast ratios of say, 30,000:1 are becoming far more common nowadays. Regulator and home-cinema installer trade body. Featuring a motion-control box hooked up to a specifically designed chair, the D-BOX Motion Code system moves your seat in sync with on-screen action. Motion Control data is appearing on a growing number fo Blu-ray Discs. The Digital Entertainment Group is a not-for-profit consortium of hardware and software manufacturers, and is widely credited with helping DVD become successful. The DEG plans to massively promote Blu-ray in 2008. Some Blu-ray titles have started including access to a digital copy of the film - once copied to your PC you can watch the video file on your computer or copy it to a mobile device. A form of DRM (see below) is integrated, so you won't be able to redistribute the video. A digital master, advantageous to the industry because it allows for better and easier manipulation of the media. After the post-production processes, editing and correction applied to HD film, the DI is created as a master for disc-based media, cinema and download. Used to control access to media files to ensure that copyright holder's content isn't unlawfully redistributed. An audio compression for Blu-ray and HD DVD. Audio output up to 14 channels, although it’s currently restricted to eight due to Blu-ray and HD DVD technology. Its main rival is DTS-HD Master Audio. Where a time code ‘drops’ a frame to keep synchronised with standard time. Because NTSC runs at 29.97 frames per second, a frame needs to be lost every 1,001 frames. Supporting an unlimited number of channels for surround sound, this and Dolby TrueHD both support lossless sound compression. A digital video storage media format, akin to VHS, which allows up to 50GB of HD storage. Despite its massive storage capabilities, it hasn’t come into usage as a popular video media in the home. It does get a good deal of industrial usage though, with broadcasters backing up footage on the format. A process that brings the highest and lowest volumes closer together for viewing at home. A basic form of ratio adjustment that chops the sides off a widescreen image to enable it to fit onto a smaller ratio display. A national trade organisation in the US that supports the promotion and progression of high technology through consumer shows and lobbying. The process of compressing a fi le so it takes up less space, though quality can be affected in the process. DivX, MPEG-2 and MPEG-4 are common examples of this. One half of an interlaced image; the odd or even lines of an image. Progressive scan shows full frames in their entirety. The operating system of a piece of technology. This can often be updated to offer new functions and features of resolve issues with the unit. Essential in many pieces of kit if you’re looking to future-proof your entertainment centre. A type of disc that has information on both sides. In the case of HD DVD, there will be HD content on one side and DVD-playable data on the other. Denotes the number of static images that are displayed per second, hence fps (frames per second). The human eye can’t register more than around 24fps. I frames and B frames are types of video data. I frames are complete frames. When a fi lm is encoded in full frame it will obviously take up more room than the partial frames of B frame data. B frames use less full images and are created by the previous and following frames, which predict a number of images. Currently only a measure of resolution, Full HD simply means that a display can create a 1080p image. Hopefully the industry will standardise the term to encompass different types of technology to make sure consumers get the best tech for their money. When digitally encoded, some colours (or frequencies) require more bits to show clearly. Gamma correction allocates more bits to these parts of the spectrum to maximise the detail. One billion bytes. A measure of storage space. Not to be confused with high defi nition, HDD stands for hard disk drive – digital storage drives found in PCs, settop boxes and consoles, as well as some Blu-ray drives. The rival to Blu-ray in the media storage format wars. A disc capable of storing approximately 15GB. A term used by the Consumer Electronics Association to denote a display unit with at least 720 lines of pixels, therefore allowing it to accept most HD sources. This does not dictate the quality or futureproofi ng of the unit. The HD ready logo is often seen as something of a con by the CE industry. Denotes the number of static images that are displayed per second, hence fps (frames per second). The human eye can’t register more than around 24fps. Rival to Sony’s BD-J. Developed by Microsoft and The Walt Disney Company, it’s reported to be the less expensive option of the two. Proprietary technology that disallows any unencrypted transmission of a high-def source to a display. HDMI and DVI will either downgrade or stop images completely if HDCP isn’t featured. Cable enabling the transfer of resolutions of up to 1080p to be transferred. An important aspect of any setup, HDMI cabling loses much over long distances and is often troublesome. A PC that serves as your entertainment hub. Often allowing media streaming around the house, including video and audio. Specialist hardware is required. IPTV services such as BT Vision and XBox Live allow you to download standard and HD movies and TV on demand via an internet connection. A stripped-down version of the Java that’s used on PCs. Often used in mobile phones, Blu-ray players and many electronics that use Java in a secondary capacity. Adding black borders above and below an image, to make up for the difference in aspect ratios between cinema and home viewing. Display technology using liquid crystals to produce an image on the screen. Common in the current range of HDTVs. The speed at which data is transferred. 1 Mbps = 1 million bits per second. This stands for Moving Piucture Expert Group, after the group that developed video and audio encoding standards. While watching HD material you're likely to encounter two codecs: MPEG-2, used for digital television broadcasts, standard DVD and some HD discs, and MPEG-4, which is an upgrade on MPEG-2 and can deliver the same quality picture but at a lower bitrate. Superfluous digital information added to a stream of necessary information, which often results in unwanted image imperfections. This is usually more noticeable in darker areas of the picture. 525- line, 30fps broadcasting system used in the US and Japan. When a resolution isn’t exactly matched directly to pixels, some displays will scale the image to match the display’s resolution. This has negligible real effect, being in the order of a few per cent of stretching, but isn’t ideal. More up-to-date panels and displays do away with this by simply matching the pixels to a standard HD image. The UK standard for TV broadcast, it involves 625 lines at 25 frames per second. Simply the shortened term for flat-panel television - an ultra-thin, relatively lightweight HDTV, especially those that can be wall mounted. Current flat-panel TVs come in plasma and LCD variations. A picture within a picture that usually shows commentary from cast and crew. With the new breed of Blu-ray players supporting Profile 1.1, real PiP will be available to everyone soon. The term used to describe a three-dimensional image that's so sharp it's almost tangible. Rather than using liquid crystals, a plasma unit sandwiches tiny pockets of gas and excites them to produce an image.. As Blu-ray hardware has evolved, three sets of specifications, or pofiles have emerged. Profile 1.0 (aka BD-Video) specifies a bog-standard Blu-ray player - for later profiles see BonusView and BD-Live. While interlaced images use two fields per image, progressive scan has one image. There is no interlacing possible, which makes progressive scan better for action scenes. Every colour in the visible human spectrum can be made up of these three colours. Television inputs are often separated into these three colour bands. Images are created entirely of a combination of red, green and blue. Similar to PAL (625 lines, 25 fps) broadcasting system used in France and the Middle East. The defining body responsible for setting guidelines for numerous industry standards. Format with a resolution of 480i or 480p. It has a picture ratio of 4:3 or 16:9 and needs less bandwidth to broadcast. Streaming media allows you to view content across a network (such as the internet) in real time, rather than accessing a file after it has finished downloading. Future-definition technology currently being developed by NHK, the Japanese Broadcasting Corporation, and the BBC. Also known as Ultra High Definition, the format produces pictures at a stunning 7,680 x 4,320 pixel resolution, 16 times that of HDTV. Broadcast trials are around seven years away, while full-time broadcasts will take more than 15 years to emerge. An audio standard mark that ensures a film / game sounds exactly as you were intended to hear it. A hybrid of HD DVD and Blu-ray announced by Warner. Blu-ray on one side, HD DVD on the other. So far yet to hit anywhere near stores, though. A method of improving a standard-def image by increasing the pixel. It cannot produce anything like the quality of TrueHD, but does improve images. Possibly the next wave of resolutions. Sharp has produced a prototype 64-inch HDTV with a resolution of almost 9 megapixels. The 40,000 x 20,000 pixel resolution is over quadruple the current 2-megapixel standard of current technology. There’s speculation that this technology might hit the commercial cycle sometime in the next five to ten years. A video codex alternative to AVC, VC-1 is based on Windows Media Video version 9. Blu-ray Discs support VC-1 encoding, meaning a number of Blu-rays feature the codec. Content that becomes available when the user requests it. Cable and satellite subscription services offer programmes and fi lms on demand, while the BBC and Channel 4 offer online applications to catch up with their programming.