1080p

1080p is the shorthand name for a category of video modes. The number 1080 stands for 1080 lines of vertical resolutionBrian L. Clark. What’s this 1080p Stuff? March 13, 2006., while the letter p stands for progressive scan or non-interlaced. 1080p is considered to be an HDTV video mode. The term usually assumes a widescreen aspect ratio of 16:9, implying a horizontal (display) resolution of 1920 dots across and a frame resolution of 1920 × 1080 or over two million pixels. The frame rate in hertz can be either implied by the context or specified after the letter p (such as 1080p30, meaning 30 frames per second).

While 1080p is sometimes referred to in marketing materials as "True High-Definition" or "Full High-Definition", what constitutes high-definition is continually evolving over time. 1080p is currently the digital standard for filming digital motion pictures. Directors such as George Lucas (in Revenge of the Sith) shoot their digital films in this high definition mode to be shown in theaters equipped with 1080p digital projectors.

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). 1080p30 is currently the most bandwidth-intensive video mode supported. If the standard MPEG-2 compression is used, versions with higher frame rate such as 1080p50 and 1080p60 could only be sent over higher-bandwidth channels; to send these over normal-bandwidth channels, a more modern codec such as the H.264/MPEG-4 AVC codec must be used. Higher frame rates such as 1080p50 and 1080p60 are currently for private or internal use only, and are not part of the broadcasting standard.

The ATSC is considering amending its standard to allow the incorporation of the newer codecs for optional usage like the DVB Consortium already has done with DVB-S2. However, this 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 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 (i.e. both a 1080i or 720p MPEG-2 stream alongside a 1080p MPEG-4 stream) on the same broadcast channel.

Production standards

A new high-definition progressive scan format for picture creation is currently being developed to operate at 1080p at 50 or 60 frames per second. This will require a whole new range of studio equipment including cameras, storage, edit and contribution links as it has doubled the data rate of current 50 or 60 field interlace 1920 × 1080 from 1.485 Gb/s to nominally 3 Gb/s. It is unable to be broadcast in a compressed transmission to current MPEG-2 based HD receivers. This format will improve final pictures because of the benefits of "oversampling" and removal of interlace artifacts.

Availability

1080i film-based content can become true 1080p

The following examples refer to content that is encoded in progressive-scan form during recording or transmission—what would be considered "native" progressive signals. However, where 24 fps film-based material is concerned, a 1080i encoded/transmitted stream can become a true "1080p" signal during playback by deinterlacing to re-combine the split field pairs into their original progressive film-scanned frames. Regarding 24 fps film-source material presented in conventional 1080i60 form, the deinterlacing process that achieves this goal is usually referred to as "3-2 pulldown reversal". The importance of this is that, where film-based content is concerned, all 1080-interlaced signals are potentially 1080p signals given the proper deinterlacing. As long as no additional image-degradation steps were applied during signal mastering (such as excessive vertical-pass filtering), the image from a properly deinterlaced film-source 1080i signal and a native-encoded 1080p signal will look exactly the same. As more and more processors and displays come to market able to apply 3-2 pulldown reversal to film-based 1080i60 signals, the amount of available "1080p" content for viewing expands (encompassing film-based 1080i60 feeds from broadcast HD, cable, and satellite).

Broadcasts

Even though various television networks in the world broadcast HDTV programming in 1080i and 720p, no 1080p broadcasting actually exists at this time. Material that has been digitized from a 35-mm film source is basically 1080p24 though, fit into 1080i50 or 1080i60 (progressive with segmented frames) and with proper 3-2 reversal deinterlacing, can be converted back into a true 1080p signal (see above explanation).

Internet Content

There has been some content released in the 1080p format on the internet. Some notable examples include Microsoft's WMV HD Content Showcase, and the Apple trailers in HD format. 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.

Consumer televisions

There is a growing selection of consumer televisions with native 1080p at this time. Among the television sets with a 1080p resolution, however, some are not capable of both accepting and reproducing a 1080p input signal, especially via a digital input such as Digital Visual Interface (DVI) or High-Definition Multimedia Interface (HDMI).David Katzmaier. Can 1080p HDTVs handle 1080p sources? November 18, 2005. In 2003, Sony released Qualia 004, a 1080p-resolution front-projector (it could not accept 1080p signals), while Mitsubishi released a 1080p rear-projection TV; both were based on LCoS technology and had limited availability. Several televisions in 2005 offered 1080p, including sets from Hewlett-Packard, Mitsubishi, Westinghouse Digital, Samsung and Sony. The 2006 Consumer Electronics Show (CES) introduced 1080p displays from most manufacturers, available in various display technologies. Also, 3-2 pulldown reversal 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, albeit as a non-standard resolution since most CRT monitors have an aspect ratio of 4:3. Most 17-inch computer monitors which support 1280 × 1024 at 60 Hz will accept an input signal at 1920 × 1080 at 60 Hz, although the projected resolution will not exceed the physical limitations of the display screen itself, which for CRT devices is commonly documented as phosphor dot pitch. Some modern widescreen liquid crystal display (LCD) monitors can also natively display 1080p content. Widescreen WUXGA monitors for example support 1920x1200 resolution, which can display a pixel for pixel reproduction of the 1080p (1920x1080) format. These resolutions are supported by several laptops with 15.4 and 17 inch displays.

Storage format

1080p-encoded titles have been released on HD DVDGerry Block. HD-DVD Officially Launched, April 18, 2006. and also on Blu-ray Disc. However, the first generation of HD-DVD players can only output the content at 1080i resolution (see above for an explanation of why this may not lead to any difference in some cases). After a hardware generation or two, it is expected that HD DVD players will allow output of full 1080p via copy-protected HDMI connections, thereby catching up with Blu-ray disc players, which are able to output 1080p video from the first hardware generation, at least for some models (for example, the Samsung BD-P1000). Output of film-based material in conventional 1080i60 form will also be available, and 1080p displays that are able to apply 3-2 pulldown reversal could 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. These titles cannot be played in normal DVD players and can only be viewed on a Windows-based computer with a 3.0 GHz Intel Pentium 4 equivalent or better CPU, among other hardware requirements.Microsoft. High Definition Quality with Windows Media Video 9. Accessed May 1, 2006.

References

External links

Full HDTV
More HDTV Displays Offering Native 1080p. January 8, 2005.
1080i vs. 1080p HDTV: should you care?
The Facts and Fiction of 1080p. April 17, 2006.

Video formats

1080p | 1080p | 1080p | 1080p

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