Enhanced-definition television, extended-definition television, or EDTV is a CEA marketing shorthand term for certain digital television (DTV) formats and devices. EDTV generally refers to video with picture quality beyond what is broadcastable in NTSC or PAL, but not sharp enough to be considered high-definition television (HDTV). A DVD player with progressive output is considered the lower end of this class, when playing a progressively encoded disc. (The maximum EDTV frame rate of 60 per second is not possible from a DVD.) The common implementations of EDTV are 480 or 576-line signals in progressive scan (as opposed to 50-60 interlaced fields per second, see NTSC, or PAL and SECAM). These are commonly referred to as "480p" and "576p" respectively. In comparison, a standard-definition television (SDTV) signal is broadcast with interlaced frames and is commonly referred to as "480i" or "576i". EDTV can also refer to a display device that has a maximum resolution of 480p or 576p. Because EDTV signals use a progressive scan, they have about 50% more perceived vertical resolution than interlaced SDTV pictures with the same number of lines, and do not show the spatial/temporal aliasing artifacts associated with interlaced video. As a result, EDTV material gives much better results when upconverted for display on HDTV television sets, especially sets that natively use a progressive scan. However, because of the higher level of spatial coherence within single progressive frames as compared to single interlaced fields, EDTV does not increase the amount of data bandwidth proportionately to the greater number of pixels displayed per second. EDTV signals require more bandwidth than is feasibly possible with SDTV connection standards, such as composite video or S-Video. As such, higher bandwidth mediums must be used to accommodate the additional data transfer needed for EDTV content to stream properly. In the case of consumer electronic devices such as a video game console or progressive scan DVD player, such devices must be connected to a display through at least a component video cable (typically using 3 RCA cables for video), though other, higher quality connections exist which are also EDTV compatible. For over-the-air television broadcasts, EDTV content is broadcast digitally to meet the bandwidth limitation, as digital broadcasting uses less bandwidth than the analog broadcast standard. Nevertheless, EDTV signals still use less bandwidth than HDTV signals. A DTV station may broadcast multiple programs at once while still improving quality over standard broadcasts, giving more streams per channel than HDTV. EDTV signals are often broadcast in a 16:9aspect ratio, with non-square pixels. The horizontal resolution is 704 or 720 pixels regardless of intended aspect ratio. However, some consumer devices such as a video game console typically use a horizontal resolution of 640 square pixels when outputting an EDTV signal. The image is then stretched for displaying to an aspect ratio of 4:3 or 16:9 as necessary. As theatrical widescreen resolutions do not exist in the EDTV standard, they are instead achieved through the use of anamorphic widescreen. In the United States, the ATSC official DTV formats include SDTV and HDTV. EDTV is not technically considered part of the HDTV standard. Video game consoles also make use of the EDTV resolution, starting with the 6th generation of consoles around the year 2000. Initially there were some production blocks on implementing EDTV support for games among developers, as the presence of progressive scan televisions in homes was relatively small at that time. As a consequence, 480p support was deemed superfluous and was not developed for all games. As time went on, ED/HD support for console games became more widespread along with ED/HD televisions. Nintendo's current, 7th generation video game console, Wii, has a maximum output resolution of 480p for nearly all its games, which is EDTV. Games for the Xbox 360 and Playstation 3 can also output in 480p in addition to HD resolutions such as 720p and 1080i and 1080p.
This table illustrates total horizontal and vertical pixel resolution via box size. It does not accurately reflect the screen shape (aspect ratio) of these formats, which is either 4:3, or 16:9.
