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Enhanced-definition television, orextended-definition television (EDTV) is aConsumer Electronics Association (CEA) marketing shorthand term for certaindigital television (DTV) formats and devices. Specifically, this term defines an extension of thestandard-definition television (SDTV) format that enables a clearer picture during high-motion scenes compared to previous iterations of SDTV, but not producing images as detailed ashigh-definition television (HDTV).
The term refers to devices capable of displaying 480-line or 576-line signals inprogressive scan, commonly referred to as480p (NTSC-HQ) and576p (PAL/SECAM) respectively, as opposed tointerlaced scanning, commonly referred to as480i (NTSC) or576i (PAL, SECAM).High-motion is optional for EDTV.[1]
InAustralia, the 576p resolution standard was used by theSpecial Broadcasting Service (SBS TV) andSeven Network, being technically considered high-definition.[2][3]
In Japan, the term is associated with improvements to analog NTSC calledEDTV-I (or "Clear-vision") and EDTV-II (or "Wide-aspect Clear-vision") including ghost cancellation, digital sound or widescreen broadcasts, using a methods vaguely similar to PALPlus.[4][5][6]
In Europe, it can be applied to analogPALPlus orMAC broadcasts.[7] In other countries definitions may vary.
As EDTV signals require morebandwidth (due to frame doubling) than is feasible with SDTV connection standards (such ascomposite video,SCART orS-Video), higher bandwidth media must be used to accommodate the additional data transfer. To achieve EDTV, consumer electronic devices such as aprogressive scan DVD player or modernvideo game consoles must be connected through at least acomponent video cable (typically using 3 RCA cables for video), aVGA connector, or aDVI orHDMI connector. For over-the-air television broadcasts, EDTV content uses the same connectors as HDTV.
EDTV broadcasts use less digital bandwidth than HDTV, so TV stations can broadcast several EDTV stations at once. Like SDTV, EDTV signals are broadcast with non-square pixels. Since the same number of horizontal pixels are used in 4:3 and 16:9 broadcasts, the 16:9 mode is sometimes referred to asanamorphic widescreen. Most EDTV displays use square pixels, yielding a resolution of 852 × 480. However, since no broadcasts use this pixel count, such displays always scale anything they show. The only sources of 852 × 480 video are Internet downloads, such as some video games. Unlike 1080i and SDTV formats, progressive displays (such asplasma displays and LCDs) can show EDTV signals without the need to de-interlace them first. This can result in a reduction of motion artifacts. However to achieve this most progressive displays require the broadcast to be frame doubled (i.e., 25 to 50 and 30 to 60) to avoid the same motion flicker issues that interlacing fixes.
The progressive output of aDVD player can be considered the baseline for EDTV. Movies shot at 24 frames-per-second (fps) are often encoded onto a DVD at 24 fps progressive. Fortelecine sources, most DVD players can do the2:2 or 3:2 pulldown conversion dealing with deinterlacing internally, before feeding the output to a progressive 576p or 480p display.[8][9]
Blu-ray Discs can encode all EDTV forms, but because HDTV is a primary selling point of Blu-ray, this is only used for certain bonus content such as featurettes, deleted scenes, interviews and behind the scenes documentaries on the making of the film.
The video resolution of video game consoles reached EDTV specifications starting with theSegaDreamcast, becoming the first mainstream console with a VGA output, supporting EDTV. ThePlayStation 2,GameCube,original Xbox andWii are also EDTV compatible with a component connection. TheXbox 360 can output 480p viaYPBPRcomponent,VGA andHDMI (newer models only) cables. ThePlayStation 3 outputs EDTV via its HDMI and component video (YPBPR) connections; 480p is only available on NTSC consoles while 576p is only available on PAL consoles.
Despite 576p being a valid output from the PS2's component out, it is never used by any games released in PAL territories; instead the few games retaining progressive scan mode in their PAL localizations output in 480p. There are homebrew solutions available to force the output to progressive scan mode (which also in turn allows 60 Hz modes for 720p and 1080p: neither of which were otherwise used in any capacity officially).
