High-definition television

High-definition television (HDTV) is a digital television broadcasting system with greater resolution than traditional television systems (NTSC, SECAM, PAL). HDTV is digitally broadcast because digital television (DTV) requires less bandwidth if sufficient video compression is used. HDTV technology was introduced in the United States in the 1990s by the Digital HDTV Grand Alliance, a group of television companies.

Availability

Broadcasts

Various television networks in the world broadcast HDTV programming in 1080i and 720p; no 1080p broadcasting exists at this time. However, material that has been digitized from a 35 mm film source is basically 1080p/24, fit into 1080i/50 or 1080i/60 (progressive with segmented frames). With proper 3:2 deinterlacing reversal, it can be converted back into a true 1080p/24 signal.

Internet content

There has been some content released in the 1080p format on the Internet. Some notable examples include the Apple QuickTime Trailers in the QuickTime HD 720p/1080p format, and the Microsoft WMV HD Content Showcase which offers clips in both 720p and 1080p formats. Another example of 1080p content is the MacBreak 1080p podcast created by Leo Laporte and Alex Lindsay. This podcast is distributed via the BitTorrent method of distribution because of the large file sizes resulting from the high bit-rates. All 1080p content currently (as of March 2007) distributed on the Internet has frame rate of 24, 25, or 30 frames per second.

Consumer televisions and projectors

There is a growing selection of consumer televisions with support for both 1080p inputs and outputs. Several televisions in 2005 offered 1080p, including sets from JVC (using a technology called D-ILA which is a variation of LCoS), Hewlett-Packard, Mitsubishi, Sony, Panasonic, etc. The 2006 Consumer Electronics Show (CES) introduced 1080p displays from most manufacturers, available in various display technologies. The manufacturers of 1080p TFT LCD screens include Sharp and a few others in Asia. Also, 3:2 pulldown reversal (reverse telecine) for film-based 1080i60 signals is beginning to appear in some newer 1080p displays, which can produce a true 1080p quality image from film-based 1080i60 programs.

Computer monitors

Cathode ray tube (CRT) computer monitors have long been capable of displaying (and exceeding) 1080p. However, since most CRT monitors have an aspect ratio of 4:3 (and those that are widescreen have a ratio of 16:10, not 16:9), one would need a monitor with enough range in the vertical sizing control in order to squeeze the raster to a 16:9 aspect ratio so as to properly display a 1080p source. Most 17-inch computer monitors which support 1280×1024 at 60 Hz will accept an input signal at 1920×1080 at 60 Hz. This is because CRT circuitry only places hard limits on the scanline rate (i.e., vertical resolution) and not on the actual bandwidth of the video signal itself (i.e., horizontal resolution). In practice, the ability of the viewer to resolve adjacent pixels (which affects perceived image sharpness) on a CRT will highly depend on the dot pitch (basically, how much adjacent pixels overlap) as well as the high-bandwidth roll-off of the monitor circuitry. Relatively inexpensive CRT monitors (such as a consumer grade 17" monitors) will likely not have the dot pitch necessary to fully resolve adjacent pixels of a 1080p image. Nevertheless, due to the inherent design of the CRT display itself, all pixels will always occupy the correct locations onscreen even if adjacent pixels show significant overlap.

Some modern widescreen liquid crystal display (LCD) monitors can also natively display 1080p content. Widescreen WUXGA monitors for example support 1920×1200 resolution, which can display a pixel for pixel reproduction of the 1080p (1920×1080) format. These resolutions are supported by several laptops with 15.4 and 17 inch displays. Additionally, many 23, 24 and 27 inch widescreen LCD displays use 1920×1200 as their native resolution. Other 1080p-compatible LCDs, on the other hand, have lower than 1920×1080 native resolution and cannot display 1080p pixel for pixel. The output is resized; though it may not be noticeable to the viewer, what is seen is a slightly degraded version of the original image.

Storage format

1080p-encoded titles have been released on HD DVD and also Blu-ray Disc. The first generation of U.S./Japanese HD DVD players could only output the 1080p content via 1080i signal and required 3:2 pulldown deinterlacing in a display to reconstruct the original 1080p signal (see above for an explanation of why this does not lead to any difference between 1080i and 1080p in many cases). However, the second generation U.S./Japanese HD DVD players and the first generation of European HD DVD players (both launched in Q4-2006) support direct output of 1080p signal. Since the introduction of their first hardware generation, Blu-ray Disc players have been able to output 1080p video. As well as 1080p output, current HD DVD and Blu-ray Disc players both allow output of film-based material in conventional interlaced 1080i60 form, and 1080p displays that are able to apply 3:2 pulldown reversal can deinterlace film-based content and achieve full 1080p image quality.

1080p and near-1080p content has also been released on regular DVD-ROM disks using WMV HD compression. Although these titles could not be viewed for a while in normal DVD players, they can be played back by some current generation DVD players (such as the Kiss DP-600), or on modern computers, given sufficient processing power and the right software.

Video game consoles

Video games can also be rendered at 1080p, and some consoles can also be used to display non-game 1080p content. Sony's PlayStation 3 and Microsoft's Xbox 360 are capable of 1080p output. All versions of the PlayStation 3 have an HDMI (1.3 compliant) connection. All versions of the Xbox 360 after August 2007 support HDMI with them supporting 1080p through VGA and component..

Many modern computer games can run at 1080p or higher, limited only by the size and viewing dimensions of the monitor, the speed and computing abilities of the computer and video card, and the bandwidth of the connection between them.

Broadcasting standards

Due to bandwidth limitations of broadcast frequencies, the ATSC and DVB have standardized only the frame rates of 24, 25, and 30 frames per second (1080p24, 1080p25, 1080p30). Higher frame rates, such as 1080p50 and 1080p60, could only be sent over normal-bandwidth channels if a more advanced codec (such as H.264/MPEG-4 AVC) were used. Higher frame rates such as 1080p50 and 1080p60 are foreseen as the future broadcasting standard for production.

In the United States, the ATSC is considering amending its standard to allow the incorporation of the newer codecs for optional usage like the DVB Project consortium already has done with DVB-S2. However, doing so is not expected to result in widespread consumer availability of broadcast 1080p programming, since most of the existing digital television sets or external digital receivers in use in the United States would still only be capable of decoding the older, less-efficient MPEG-2 codec, while the bandwidth limitations do not allow for broadcasting two simultaneous streams on the same broadcast channel (e.g. both a 1080i MPEG-2 stream alongside a 1080p MPEG-4 stream).

1080p

1080p is the shorthand name for a category of display resolutions. The number "1080" represents 1,080 lines of vertical resolution, while the letter p stands for progressive scan (meaning the image is not interlaced). 1080p is considered an HDTV video mode. The term usually assumes a widescreen aspect ratio of 16:9, implying a horizontal resolution of 1920 pixels. This creates a frame resolution of 1920×1080, or 2,073,600 pixels in total. The frame rate in Hertz can be either implied by the context or specified after the letter p, such as 1080p30, meaning 30 Hz.

1080p is sometimes referred to in marketing materials as "Full High-Definition". Although 2K/4K digital cinema technology is commercially available, and ultra-high definition video is in the research phase, 1080p and 1080i are currently the highest-resolution formats widely used for broadcasting and consumer distribution of video content.