Aspect Ratio - the ratio of image width to image height. The term may apply to the display device configuration, or the shape of the content being displayed. (See Letterboxing) HDTV uses an aspect ratio of 16 units wide by 9 units high. Conventional television programming and displays are at an aspect ratio of 4 - 3. Digital SDTV programs may aspect ratios from 4 - 3 to 16 - 9, dependant on content and its source (e.g. upconverted NTSC is likely to be 4 - 3).
CEMA - Consumer Electronics Manufacturers Association. A U.S. industry group representing manufacturers of consumer electronics products
DTS - Digital Theatre Sound System. A Dolby proprietary discrete 5.1 channel surround system similar to, but not the same as Dolby Digital AC-3, the DTV standard. DTS is used in cinema presentations and in DVD's.
Fire Wire - A digital interface originated by Apple Computer that can transport data at 100, 200, or 400 Mbps. It is widely used to interconnect digital video devices, such as cameras and displays. Also referred to as IEEE- 1394.
PSIP - Acronym for "Program and system information protocol", an ATSC DTV specification that enables a DTV receiver to identify the program information and to create on-screen electronic program guides and content advisories.
Progressive Scanning - Some HD televisions use the "progressive" method of scanning, in which the whole picture is transmitted and presented on the screen in one pass. The resulting image is thus remarkably free of flicker and motion artefacts, appearing more "life-like". Some display types, such as LCD, plasma and DLP are inherently of the progressive scan type, while CRT's may be scanned progressively (as in computer monitors) or interlaced.
Reverse 3 - 2 Pull-Down - DTV material originating on film at 24 fps is converted to the 30 fps of DTV by repeating field or frames, resulting in some motion artefacts. Some film presentations remove these repeated images before transmission and send a signal to the television causing it to process (termed Reverse 3 - 2 Pull-Down) this material appropriately to make it suitable for display. In this way, the displayed material closely matches the original film quality, avoiding the motion artefacts.
4 - 3 - Aspect ratio of traditional NTSC TV screens, with 4 unit width by 3 unit height.
Computer Input - Some HDTV sets have an input like SVGA or VGA that allows the TV sets to be connected to computers.
Digital Tuner - A digital tuner serves as the decoder required to receive and display digital broadcasts. It can be included inside TV sets or via a set-top box.
