High-definition television (HDTV) means broadcast of television signals with a higher resolution than traditional formats allow.

HDTV is defined as 1080 active lines, with an aspect ratio of 16 x 9. Non-cinematic HDTV video recordings are recorded in either 720p or 1080i format. The format depends on the broadcast company if destined for television broadcast, however in other scenarios the format choice will vary depending on a variety of factors. In general, 720p is more appropriate for fast action as it uses progressive fields, as opposed to 1080i which uses interlaced fields and thus can have a degradation of image quality with fast motion. In addition, 720p is used more often with internet distribution of HD video, as all computer monitors are progressive, and most graphics cards do a sub-optimal job of de-interlacing video in real time. 720p Video also has lower storage and decoding requirements than 1080i or 1080p, and few people possess displays capable of displaying the 1920x1080 resolution without scaling. 720p appears at full resolution on a common 1280x1024 LCD, which can be found for under $250. An LCD capable of native 1080i resolution costs close to a thousand dollars, however models by Dell, HP and Gateway capable of displaying full 1080i and 1080p resolution have had price points lower than $1,000.

Advantages of HDTV

  1. All commercial HD is digital, so the signal will either deliver an excellent picture, a picture with noticeable pixelation, a series of still pictures, or no picture at all. You would never get a snowy or washed out image from a weak signal, effects from signal interference, such as herringbone patterns, or vertical rolling.
  2. Most HD programming and films will be presented in the 16x9 proportioned, semi-widescreen format (though some films created in even wider ratios will still display "letterbox" bars on the top and bottom of even 16:9 sets.) Older films and programming that retain their 4:3 ratio display will be presented in a version of letterbox commonly called "pillar box", displaying bars on the right and left of 16:9 sets (rendering the term "fullscreen" a misnomer). Or, one can usually choose to enlarge the image to fill the screen, however this option will display a distorted, stretched-out picture.
  3. The colors will generally look more realistic, due to the cleaner signal.
  4. The visual information is about 2-5 times more detailed overall. The gaps between scanning lines are smaller or invisible. Legacy TV content that was shot and preserved on 35mm film can now be viewed at nearly the same resolution as that at which it was originally photographed.
  5. Two new pre-recorded disc formats will be available in spring 2006. One is called HD DVD, the other is Blu-ray. Both systems will usually play current DVDs, and attempt to extract a near-HDTV-quality image from them, but they are not compatible with each other.
  6. The increased clarity and detail make larger screen sizes more comfortable and pleasing to watch.
  7. Dolby Digital 5.1 sound is broadcast along with standard HDTV video signals allowing full surround sound capabilities. (standard television signals broadcast basic stereo audio signals)

HDTV can be recorded to D-VHS (Data-VHS), W-VHS, to an HDTV-capable digital video recorder such as DirecTV's high-definition TiVo or Dish Network's DVR 921, 942 or VIP622, or to a computer equipped with an HDTV capture card. In the U.S., the only current archival option is D-VHS. D-VHS digitally records a 28.2-Mbit stream onto a classic VHS tape, using a FireWire (IEEE 1394) digital transport to carry a compressed MPEG-2 Transport Stream from the tuning device to the recorder.

However, the massive amount of data storage required to archive uncompressed streams make it unlikely that an uncompressed storage option will appear in the consumer market soon. Realtime MPEG-2 compression of an uncompressed digital HDTV signal is also prohibitively expensive for the consumer market at this time, but should become inexpensive within several years (although this is more relevant for consumer HD camcorders than recording HDTV). Analog tape recorders with bandwidth capable of recording analog HD signals such as W-VHS recorders are no longer produced for the consumer market and are both expensive and scarce in the secondary market.

As part of the FCC's "plug and play" agreement, cable companies are required to provide customers that rent HD set-top boxes with a set-top box with "functional" Firewire (IEEE 1394) upon request. None of the DBS providers have offered this feature on any of their supported boxes. As of July 2004, boxes are not included in the FCC mandate. This content is protected by encryption known as 5C. This encryption can prevent someone from recording content at all or simply limit the number of copies.

HD programming may be recorded on optical disc using Blu-ray Disc or HD DVD. Blu-ray technology is currently available only in Japan with a Japanese satellite/terrestrial tuner, but is expected to be released in other world markets on May 23, 2006. Blu-ray uses a blue-laser optical disc with an MPEG-2 or MPEG-4 codec. Sony will include a Blu-ray player in its forthcoming gaming console, the PlayStation 3, which was announced to be released during early November 2006. It is expected to have a big impact on the HDTV market. Similarly, Microsoft's Xbox 360 doesn't ship with an HD DVD-compatible player as standard at present (as opposed to Blu-Ray), but the company plans on releasing an external HD-DVD drive in the near future.

Many are regarding this difference in support for the two HD formats (provided Microsoft ship their HD-DVD drive in time) as the precursor to the next full-blown format war, and the indicator as to which format will win out in the end. Discussion is mainly centering around which of the consoles will reach sufficient numbers in terms of the at-home installation base to guarantee one HD format's success over the other (combined with the race to see which manufacturer can produce standalone players at reasonable price points, these two things - that, and movie studio support for the two formats - will be the main contributors to bringing the ownership of compatible devices to critical mass, and resolving the inevitable format war).