HDTV - The Best Buy on High Definition Televisions Ever!
(by 2 people)
Your rating:
What is High Definition Television or HDTV
Presented by TelecommunicationShop.com and Free-Wireless-Cellphones.com
Free Bluetooth Cell Phones and Cell Phone Accessories
Free Blackberry Cell Phones and Cell Phone Accessories
Free TV Cell Phones - Watch Television on Your Cell Phone
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.
Don't forget to share this website with a few of your friends ...
High Definition Television (HDTV) Videos
All about HDTVs ...
Watch these very interesting and informative videos of HDTV on YouTube.com!
History of High-Definition Television!
All about HDTV ...
The term high definition described the television systems of the 1930s and 1940s beginning with the British 405-line black-and-white system, introduced in 1936; however, it and the American 525-line NTSC system established in 1941, were high definition in comparison with previous mechanical and electronic television systems. Today, the American 525-line NTSC system and the European 625-line PAL and SECAM systems are standard definition television, whereas the post-WWII French 819-line black-and-white system, was high definition in the contemporary sense, it required more bandwidth and was discontinued in 1986, a year after the final British 405-line broadcast.In 1958, the U.S.S.R. created %u0422%u0440%u0430%u043D%u0441%u0444%u043E%u0440%u043C%u0430%u0442%u043E%u0440 (Transformer), the first high-resolution (definition) television system capable of producing an image composed of 1,125 lines of resolution for the purpose of television conferences among military commands; as it was a military product, it was not commercialised.
In 1969, NHK of Japan first developed commercial, high-definition television. However, the system was not commercialized until late in the 1990s.
In 1981, the first HDTV demonstration in the United States was held. It had 5:3 aspect ratio like the Japanese system.
In 1983, the International Telecommunication Union's radiotelecommunications sector (ITU-R) set up a working party (IWP11/6) with the aim of setting a single international HDTV standard. This WP considered many views and through the 1980s served to encourage development in a number of video digital processing areas such as conversion between 30/60 and 25/50 picture rates using motion vectors that led to other outcomes. While a single standard was never finalized, a common aspect ratio of 16:9 was agreed to at the first meeting at the BBC's R & D establishment at Kingswood Warren. Initially the Japanese 5:3 ratio was considered but a proposal to widen it to 16:9 was accepted. 16:9 aspect ration was seen as a good compromise between the European 1.66 cinema aspect ratio and the 1.85 aspect ratio used in motion pictures in the United States.
The resulting ITU-R Recommendation ITU-R BT.709-2 ("Rec. 709") includes the 16:9 aspect ratio, specified colorimetry, and 1080i (1,080 actively-interlaced lines of resolution) and 1080p (1,080 progressively-scanned lines) scanning modes. It also includes the 1440 x 1152 HDMAC scanning format. According to some reports, 720p format was viewed by some at the ITU, unofficially, as an "enhanced" television format rather than an HDTV format, and was not standardized there. Both 1920x1080 and 1280x720p (720 progressively-scanned lines) systems for a range of frame and field rates are also defined by several SMPTE standards.
However, the standardization of HDTV did not lead to its adoption. Early HDTV commercial experiments such as NHK's MUSE required over four times the bandwidth of a standard definition broadcast, and despite the effort made to shrink the required bandwidth into about 2 times of that of the SDTV's, it still was distributable only by satellite. In addition, recording and reproducing an HDTV signal was also a technical challenge in the early years of HDTV.
HDTV technology was introduced in the United States in the 1990s by the Digital HDTV Grand Alliance, a group of television companies and MIT.
On, April 6, 1997 CBS went on the air with WCBS-HD from the top of the Empire State Building, New York, doing demos and evaluations. The first HDTV sets went on sale in the United States in 1998.
Japan is the only country with successful commercial analog HDTV, known as "Hi-vision", featuring a 5:3 aspect ratio screen with 1,125 interlaced lines (1,035 active lines) at the rate of 60 fields per second. Elsewhere, in Europe, analog 1,125-line HD-MAC television failed in its test broadcasts in the early 1990s.
However, it was not until the early 2000s that storage means of enough capacity and computer processing power for dense compression algorithms made commercial applications of HDTV affordable for consumers and profitable for TV channels or the video rental industry.
HDTV became viable due to the transition from analog to digital TV broadcasting. Digital compression methods such as MPEG-2 and MPEG-4 allow the bandwidth of a single TV channel (in the US, 6 MHz) to carry up to 5 TV programs of standard definition or up to 2 channels of high definition.
Current HDTV broadcast standards include ATSC (US) and DVB (Europe, and most of the rest of the world). HDTV can also provide 5.1-channel surround sound audio using e.g. the Dolby Digital (AC-3) format.
On February 17, 2009, the US will terminate all full power station (some smaller local stations have later deadlines) terrestrial analog broadcasting in favor of digital broadcasting, which can be standard-definition (SDTV) or HDTV.
Great Samsung HDTV (High Definition Televisions) on Amazon!
All about HDTVs ...
Find fantastic bargains on Samsung HDTVs right here at Amazon.com!
Samsung LN46A650 46-Inch 1080p 120Hz LCD HDTV with RED Touch of Color
Amazon Price: Too low to display (as of 09/07/2008)
Samsung LN52A650 52-Inch 1080p 120Hz LCD HDTV with Red Touch of Color
Amazon Price: Too low to display (as of 09/07/2008)
Samsung LN40A550 40-Inch 1080p LCD HDTV
Amazon Price: Too low to display (as of 09/07/2008)
Samsung LN32A450 32-Inch 720p LCD HDTV
Amazon Price: Too low to display (as of 09/07/2008)
Samsung LN40A650 40-Inch 1080p 120Hz LCD HDTV with RED Touch of Color
Amazon Price: Too low to display (as of 09/07/2008)
Broadcast Station Format Considerations!
All about HDTV ...
At the least, HDTV has twice the linear resolution of standard-definition television (SDTV), thus showing greater detail than either analog television or regular DVD. The technical standards for broadcasting HDTV also handle the 16:9 aspect ratio images without using letterboxing or anamorphic stretching, thus increasing the effective image resolution.The optimum format for a broadcast depends upon the type of videographic recording medium used and the image's characteristics. The field and frame rate should match the source and the resolution. A very high resolution source may require more bandwidth than available in order to be transmitted without loss of fidelity. The lossy compression that is used in all digital HDTV storage and transmission systems will distort the received picture, when compared to the uncompressed source.
Types of medium
The high resolution photographic film used for cinema projection is exposed at the rate of 24 frames per second. Depending upon available bandwidth and the amount of detail and movement in the image, the optimum format for video transfer is either 720p24 or 1080p24. When shown on television in PAL system countries, film must be projected at the rate of 25 frames per second by accelerating it by 4.1 per cent. In NT SC standard countries, the projection rate is 30 frames per second, and using a technique called 3:2 pull-down. One film frame is held for three video fields (1/20 of a second), and the next is held for two video fields (1/30 of a second) and then the process is repeated, thus achieving the correct film projection rate with two film frames shown in 1/12 of a second. Template:Cf.
Older (pre-HDTV) recordings on video tape such as Betacam SP are often either in the form 480i60 or 576i50. These may be upconverted to a higher resolution format (720i), but removing the interlace to match the common 720p format may distort the picture or require filtering which actually reduces the resolution of the final output.
See also: Deinterlacing
Non-cinematic HDTV video recordings are recorded in either the 720p or the 1080i format. The format used is set by the broadcaster (if for television broadcast). In general, 720p is more accurate with fast action, because it progressively scans frames, instead of the 1080i, which uses interlaced fields and thus might degrade the resolution of fast images.
720p is used more for Internet distribution of high-definition video, because computer monitors progressively scan; 720p video has lower storage-decoding requirements than either the 1080i or the 1080p. This is also the medium for High Definition Broadcasts around the world and 1080p is used for Blu-Ray movies and HD-DVD.
List of stations
* In Australia, the 576p50 format is also considered an HDTV format, as it has higher vertical resolution through the use of progressive scanning. When Australia started DVB-T in 2001 several networks broadcast high-definition in a 576p format as this could give better quality on 50 Hz scanning CRT TVs and was not as demanding on MPEG-2 bit-rate. Now that flat-screens are predominating and these have an interlace to progressive scan conversion there is little difference in picture quality. Also MPEG-2 encoders have improved so the more conventional 720p and 1080i formats are now used. Technically, the 576p format is internationally defined as Enhanced-definition television and many DVD players can provide a 576p signal usually on HDMI outputs.
* In North America, FOX, MyNetworkTV (both owned by the News Corporation), ABC, and ESPN (ABC and ESPN are both owned by Disney) currently broadcast 720p content. NBC, Universal HD (both owned by the NBC Universal subsidiary of General Electric and Vivendi), CBS, The CW (co-owned by CBS and Time Warner), HBO (owned by Time Warner), Showtime (owned by CBS), Starz!, MOJO HD, HDNet ,TNT (owned by Time Warner), CNN (also owned by Time Warner), and Discovery HD Theater currently broadcast 1080i content. In Canada, virtually all over-the-air HD stations broadcast 1080i, as do most cable specialty channels. For list of local over the air HD channels visit http://www.antennaweb.org/.
* In Singapore, MediaCorp TV HD5 is Singapore's first over-the-air HDTV channel, simulcasting HD version of Channel 5 programming in 1080i. It is the first terrestrial broadcast HD channel in South-East Asia and also first in the world to use MPEG-4 AVC compression. Starhub, a Singapore cable provider also airs 3 HDTV channels: Discovery HD, National Geographic Channel HD and HD Showcase which features Barclays Premier League soccer matches.
* In the United Kingdom on Sky Digital, there are BBC HD, Channel 4 HD, Sky One HD, Sky Arts HD, Sky Movies HD1 & 2, Sky Sports HD1,2 & X, Discovery HD, National Geographic Channel HD, The History Channel HD & Sky Box Office HD1 & 2. With MTV HD, FX HD, Living HD Rush HD, Ultra HD & Eurosport HD to come in the near future. BBC HD is also available on Virgin Media. The BBC Trust has given provisional approval for a BBC HD channel, which would be broadcast satellite, cable and DTT.
o Public consultation on the Trust's provisional conclusions on the proposed BBC HD service is open until 23 October 2007.
* In Brazil all 5 major TV networks (Band, Rede Globo, Rede Record, RedeTV! and SBT) and the public television started to broadcast HDTV (1080i) in December 2007. Brazil uses a mixture of the Japanese HDTV system with Brazilian technology called SBTVD.
* In Switzerland HD Suisse channel and Arte HD broadcasts started late 2007 on the cablecom network. Cablecom provides the HD mediabox receiver (UPC) manufactured by Philips. The HD Suisse and Arte HD channels are free of charge with the basic subscription to cablecom TV. Cablecom announced more HD channels to come during 2008.
Great Panasonic HDTV (High Definition Televisions) on Amazon!
All about HDTVs ...
Find fantastic bargains on Panasonic HDTVs right here at Amazon.com!
Panasonic TC-32LX85 32-Inch 720p LCD HDTV
Amazon Price: Too low to display (as of 09/07/2008)
Panasonic Viera TH-50PZ800U 50-Inch 1080p Plasma HDTV
Amazon Price: Too low to display (as of 09/07/2008)
Panasonic Viera TH-42PX80U 42-Inch 720p Plasma HDTV
Amazon Price: Too low to display (as of 09/07/2008)
Panasonic TC-26LX85 26-Inch 720p LCD HDTV
Amazon Price: Too low to display (as of 09/07/2008)
Panasonic Viera TH-42PZ85U 42-Inch 1080p Plasma HDTV
Amazon Price: Too low to display (as of 09/07/2008)
HDTV Sources!
All about HDTV ...
The rise in popularity of large screens and projectors has made the limitations of conventional Standard Definition TV (SDTV) increasingly evident. A HDTV compatible television set will not improve the quality of SDTV channels. To display a superior picture, high definition televisions require a High Definition (HD) signal. Typical sources of HD signals are as follows:* Over the air with an antenna. Most cities in the US with major network affiliates broadcast over the air in HD. To receive this signal an HD tuner is required. Most newer high definition televisions have an HD tuner built in. For HDTV televisions without a built in HD tuner, a separate set-top HD tuner box can be rented from a cable or satellite company or purchased.
* Cable television companies often offer HDTV broadcasts as part of their digital broadcast service. This is usually done with a set-top box or CableCARD issued by the cable company. Alternatively one can usually get the network HDTV channels for free with basic cable by using a QAM tuner built into their HDTV or set-top box. Some cable carriers also offer HDTV on-demand playback of movies and commonly viewed shows.
* Satellite-based TV companies, such as DirecTV and Dish Network (both in North America), Sky Digital (in the UK and Ireland), Bell ExpressVu and StarChoice (both in Canada) and NTV Plus (in Russia), offer HDTV to customers as an upgrade. New satellite receiver boxes and a new satellite dish are often required to receive HD content.
* Video game systems, such as the Xbox (NTSC only), Playstation 2, Playstation 3, and Xbox 360 can output an HD signal. The Xbox Live Marketplace and Playstation Network services offers HD movies, TV shows, movie trailers, and clips for download to their respective consoles.
* Most newer computer graphics cards have either HDMI or DVI interfaces, which can be used to output images or video to an HDTV.
* Two optical disc standards, Blu-ray Disc (25GB-50GB) and HD DVD (15GB-30GB), can provide enough digital storage to store hours of HD video content.
Great Sharp HDTV (High Definition Televisions) on Amazon!
All about HDTVs ...
Find fantastic bargains on Sharp HDTVs right here at Amazon.com!
Sharp Aquos LC37D64U 37-Inch 1080p LCD HDTV
Amazon Price: Too low to display (as of 09/07/2008)
Sharp Aquos LC32D64U 32-Inch 1080p LCD HDTV
Amazon Price: Too low to display (as of 09/07/2008)
DigiTV Plasma and LCD TV Tilting Wall Mount. Universal Design for 40" to 70" Displays ~
Amazon Price: $46.00 (as of 09/07/2008)
Sharp Aquos LC52D64U 52-Inch 1080p LCD HDTV
Amazon Price: $1,803.99 (as of 09/07/2008)
Sharp Aquos LC46D64U 46-Inch 1080p LCD HDTV
Amazon Price: Too low to display (as of 09/07/2008)
HDTV Notation!
All about HDTV ...
HDTV broadcast systems are defined threefold, by:* The number of lines in the vertical display resolution.
* The scanning system: progressive scanning (p) or interlaced scanning (i). Progressive scanning redraws an image frame (all of its lines) when refreshing each image. Interlaced scanning redraws the image field (every second line) per each image refresh operation, and then redraws the remaining lines during a second refreshing. Interlaced scanning yields greater image resolution if subject is not moving, but loses up to half of the resolution and suffers "combing" artifacts on progressive displays when subject is moving - in case no appropriate deinterlacing applied. (There is an advantage, though: the alternating fields can hold different movement phases, effectively doubling them (1 [logical] frame = 2 field), compared to a given frame/sec progressive mode.)
* The number of frames per second or fields per second.
The 720p60 format is 1280 × 720 pixels, progressive encoding with 60 frames per second (60 Hz). The 1080i50 format is 1920 × 1080 pixels (ie 2 MP), interlaced encoding with 50 fields per second. Sometimes interlaced fields are called half-frames, but they are not, because two fields of one frame are temporally shifted. Frame pulldown and segmented frames are special techniques that allow transmitting full frames by means of interlaced video stream.
For commercial naming of the product, either the frame rate or the field rate is dropped, e.g. a "1080i television set" label indicates only the image resolution. Often, the rate is inferred from the context, usually assumed to be either 50 or 60, except for 1080p, which denotes 1080p24, 1080p25, and 1080p30, but also 1080p50 and 1080p60 in the future.
A frame or field rate can also be specified without a resolution. For example 24p means 24 progressive scan frames per second and 50i means 25 interlaced frames per second, consisting of 50 interlaced fields per second. Most HDTV systems support some standard resolutions and frame or field rates. The most common are noted below.
Standard Display Resolutions
Standard Definition usually refers to 480 vertical lines of resolution or more.
Resolution (W×H) Active Frame (W×H) Canonical Name(s) Pixels (Advertised Megapixels) Display Aspect Ratio (X:Y) Pixel Aspect Ratio - Standard "4:3" (X:Y) Pixel Aspect Ratio - Widescreen "16:9" (X:Y) Description
ITU-R BT.601 MPEG-4 ITU-R BT.601 MPEG-4
720×480 710.85×486 480i/p 345,600 (0.3) 3:2 4320:4739 10:11 5760:4739 40:33 Used for 525-line/(60 * 1000/1001) Hz video, e.g. NTSC-M
720×576 702×576 576i/p 414,720 (0.4) 5:4 128:117 12:11 512:351 16:11 Used for 625-line/50 Hz video, e.g. PAL-I
When resolution is considered, both the resolution of the transmitted signal and the (native) displayed resolution of a TV set are taken into account. Most HDTVs contain video scalers and will "upscale" or "upconvert" the transmitted signal to that of the TV's native format.
Sometimes the progressive versions of these video formats are referred to as EDTV, or "Enhanced Definition Television." This is slightly misleading, for although a progressive frame contains double the image information as that of an interlaced frame, Standard Definition is already capable of displaying progressive frames, for example in MPEG video with the appropriate "Progressive" flag set. Despite this, 480p/576p signals are not currently broadcasted.
High-Definition Display Resolutions
High Definition usually refers to 720 vertical lines of video format resolution or more.
Pixel Resolution (W×H) Video Format Pixels (Advertised Megapixels) Aspect Ratio (X:Y) Description
Image Pixel
1024×768 HD Ready, XGA 786,432 (0.8) 16:9 4:3 Typically a computer resolution; also exists as a non-standardized "HD-Ready" TV size and on PDP HDTV displays with non-square pixels
1248×702 720p Clean Aperture 876,096 (0.9) 16:9 1:1 Used for 750-line video with raster artifact/overscan compensation, as defined in SMPTE 296M
1280×720 720p, WXGA 921,600 (0.9) 16:9 1:1 Used for 750-line video, as defined in SMPTE 296M, ATSC A/53, ITU-R BT.1543, Digital television, DLP, LCD and LCOS projection HDTV displays
1366×768 720p/1080i, WXGA, HD Ready 1,049,088 (1.0) 683:384
(Approx 16:9) 1:1
Approx Typically a TV resolution; also exists as a standardized "HD-Ready" TV size. HDTV common pixel resolution, that used on LCD/PDP HDTV displays.
1024×1080 HD Ready 1080p 1,105,920 (1.1) 128:135
(Approx 4:3) 15:8 Non-standardized "HD-Ready" TV size. Used on PDP HDTV displays.
1280×1080 HD Ready 1080p 1,382,400 (1.4) 32:27
(Approx 16:9) 3:2 Non-standardized "HD-Ready" TV size. Used on PDP HDTV displays.
1440×1080 HDCAM/HDV 1080i 1,555,200 (1.6) 4:3 4:3:1 Used for anamorphic 1152-line video in the HDCAM and HDV formats introduced by Sony and defined (also as a luminance subsampling matrix) in SMPTE D11
1888×1062 1080p Clean Aperture 2,001,280 (2.0) 16:9 1:1 Used for 1152-line video with raster artifact/overscan compensation, as defined in SMPTE 274M
1920×1080 1080p, Full HD, HD Ready 1080i/p 2,073,600 (2.1) 16:9 1:1 Used for 1152-line video, as defined in SMPTE 274M, ATSC A/53, ITU-R BT.709. HDTV common pixel resolution that used on all types of HDTV technologies.
3840×2160 2160p 8,294,400 (8.3) 16:9 1:1 Quad HDTV, (there is no HD Ready 2160p Quad HDTV format)
It should be noted that the numbers used for "HD-Ready" image resolutions do not constitute acceptable 750- or 1152-line video signals in most standards-compliant hardware; in this respect terms such as "720p" and "1080p" are mostly used for advertising, though that does not necessarily mean that HD-Ready TVs labeled in this manner are incapable of accepting those formats as input.
Additionally, the "Clean Aperture" numbers are almost always contained within the frames of their respective "Production Aperture" numbers (e.g., a 1888×1062 rectangle would be contained within a 1920×1080 frame). This is to maintain compatibility with analogue signals, which can often become distorted close to the edge of the frame. It also increases the chance that a digital signal being played on overscan-enabled equipment will display the entire picture visibly.
A common pixel resolution used in HD Ready LCD TV panels is 1366 x 768 pixels instead of the ATSC Standard 1280 x 720 pixels. This is due to maximization of manufacturing yield and resolution of VGA, VRAM that comes with a 768 pixel format. Hence, LCD manufacturers adopt the 16:9 ratio compatible for the HD Ready 1080p video standard. Nevertheless, every HDTV has an overscan processing chipset to fix resolution scaling and color rendering, eg LG XD Engine, SONY BRAVIA Engine. Only when viewing 1080i/1080p HD contents under HD Ready 1080p where there is true pixel-for-pixel reproduction, and for HD ready LCD TV, do some signals undergo a scaling process which results in a 3-5% loss of picture.
Standard frame or field rates
* 23.976p (allow easy conversion to NTSC)
* 24p (cinematic film)
* 25p (PAL, SECAM DTV progressive material)
* 30p (29.97p in drop frame) (NTSC DTV progressive material)
* 50p (PAL, SECAM DTV progressive material)
* 60p (59.94p in drop frame) (NTSC DTV progressive material)
* 50i (PAL & SECAM)
* 60i (59.94i in drop frame) (NTSC, PAL-M)
Great Sony HDTV (High Definition Televisions) on Amazon!
All about HDTVs ...
Find fantastic bargains on Sony HDTVs right here at Amazon.com!
Playstation 3 Component AV Cable
Amazon Price: $19.99 (as of 09/07/2008)
Playstation 3 HDMI Cable
Amazon Price: $20.99 (as of 09/07/2008)
Sony HTCT100 Sound Bar with Sub-Woofer - Black
Amazon Price: Too low to display (as of 09/07/2008)
Sony Bravia W-Series KDL-52W4100 52-Inch 1080p 120Hz LCD HDTV
Amazon Price: Too low to display (as of 09/07/2008)
Sony Bravia XBR-Series KDL-37XBR6 37-Inch 1080p LCD HDTV
Amazon Price: Too low to display (as of 09/07/2008)
Technical Details!
All about HDTV ...
HDTV signals and colorimetry are defined by Rec. 709. MPEG-2 is most commonly used as the compression codec for digital HDTV broadcasts. Although MPEG-2 supports up to 4:2:2 YCbCr chroma subsampling and 10-bit quantization, HD broadcasts use 4:2:0 and 8-bit quantization to save bandwidth. Some broadcasters also plan to use MPEG-4 AVC, such as the BBC which is trialing such a system via satellite broadcast, which will save considerable bandwidth compared to MPEG-2 systems. Some German broadcasters already use MPEG-4 AVC together with DVB-S2 (Pro 7, Sat.1 and Premiere). Although MPEG-2 is more widely used at present, it seems likely that in the future all European HDTV may be MPEG-4 AVC, and Norway, which is currently in the progress of implementing digital television broadcasts, is using MPEG-4 AVC for present SD Digital as well as for future HDTV on terrestrial broadcasts. In parts of Sweden the standard is already in use for HDTV terrestrial broadcasting, reaching about 25-30% of the population.HDTV is capable of "theater-quality" audio because it uses the Dolby Digital (AC-3) format to support "5.1" surround sound. The pixel aspect ratio of native HD signals is a "square" 1.0, in which each pixel's height equals its width. New HD compression and recording formats such as HDV use rectangular pixels to save bandwidth and to open HDTV acquisition for the consumer market. For more technical details see the articles on HDV, ATSC, DVB, and ISDB.
Television studios as well as production and distribution facilities, use the HD-SDI SMPTE 292M interconnect standard (a nominally 1.485 Gbit/s, 75-ohm serial digital interface) to route uncompressed HDTV signals. The native bitrate of HDTV formats cannot be supported by 6-8 MHz standard-definition television channels for over-the-air broadcast and consumer distribution media, hence the widespread use of compression in consumer applications. SMPTE 292M interconnects are generally unavailable in consumer equipment, partially due to the expense involved in supporting this format, and partially because consumer electronics manufacturers are required (typically by licensing agreements) to provide encrypted digital outputs on consumer video equipment, for fear that this would aggravate the issue of video piracy.
Newer dual-link HD-SDI signals are needed for the latest 4:4:4 camera systems (Sony Cinealta F23 & Thomson Viper), where one link/coax cable contains the 4:2:2 YCbCr info and the other link/coax cable contains the additional 0:2:2 CbCr information.
An important benefit of the US switch to all-digital broadcasting is that it will free up parts of the valuable broadcast spectrum for public safety communications (such as police, fire departments, and rescue squads). Also, some of the spectrum will be auctioned to companies that will be able to provide consumers with more advanced wireless services (such as wireless broadband). (See DTV government 2009 changes)
Plus, high-definition television (HDTV) yields a better-quality image than does standard television, because it has a greater number of lines of resolution. Because the signal is a digital signal, it produces neither a snowy nor pale image from a weak signal or signal interference effects, such as herringbone patterns, or vertical rolling. Image colours are more realistic, because of the greater bandwidth. The visual information is some 2-5 times sharper because the gaps between the scan lines are narrower or invisible to the naked eye. Television content photographed and preserved on 35 mm film can be viewed at nearly its original resolution.
The lower-case "i" appended to the numbers denotes interlaced; the lower-case "p" denotes progressive. The interlaced scanning method, the 1,080 lines of resolution are divided into two, the first 540 lines are painted on a frame, the second 540 lines are painted on a second frame, reducing the bandwidth and increasing frame rate to 50-60 frames per second. The progressive scanning method simultaneously displays all 1,080 lines of resolution at 60 frames per second, on a greater bandwidth. (See: An explanation of HDTV numbers and laymen's glossary)
Often, the broadcast HDTV video signal soundtrack is Dolby Digital 5.1 surround sound, enabling full, surround sound capabilities, while STBC television signals include either monophonic or stereophonic audio, or both. Stereophonic broadcasts can be encoded with Dolby Surround audio signal.
In practice, the best possible HD quality is not usually achieved. The main problem is that many operators do not follow HDTV specifications fully. They may use slower bitrates or lower resolution to pack more channels within the limited bandwidth. The operators may use format that is different from the original programming, introducing generation loss artifacts in the process of re-encoding. Also, image quality may be lost if the television is not properly connected to the input device or not properly configured for the input's optimal performance, which may be difficult because of customer confusion regarding connections.
As high-definition video broadcasts are digital, the disadvantages of digital video broadcasting also apply here. For example, digital video responds differently to analogue video when subject to interference. As opposed to a lower-quality signal one gets from interference in an analogue television broadcast, interference in a digital television broadcast will freeze, skip, or display "garbage" information. Broadcasters may aggressively compress video to save bandwidth and therefore broadcast more channels - this compression manifests itself as reduced video quality.
In order to view HDTV broadcasts, viewers may have to upgrade their TVs, incurring household expense in the process. Adding a new aspect ratio makes for consumer confusion if their display is capable of one or more ratios but must be switched to the correct one by the user. Traditional standard definition TV shows and feature films (mostly movies from before 1953) originally filmed in the standard 4:3 ratio, when displayed correctly on an HDTV monitor, will have empty display areas to the left and right of the image. Many consumers aren't satisfied with this unused display area and choose instead to distort their standard definition shows by stretching them horizontally to fill the screen, giving everything a too-wide or not-tall-enough appearance. Alternately, they'll choose to zoom the image which removes content that was on the top and bottom of the original TV show.
As of 2007, broadcasters may demand, or cable-television operators may elect, to place HD signals in a premium band that requires higher cable fees. That some satellite companies offer the local HD channels as a service at additional cost (transmission comes from satellite) suggests to some broadcasters that on-air broadcasts of local HD signals must be a premium service to subscribers. Viewers may be denied some television channels that they expected, be allowed only access to the non-digital, and obviously sub-standard non-digital signal, or have to install an antenna to receive the digital broadcasts. Such issues more entail economic and legal disputes than they entail technology.
Another disadvantage of HDTV compared to traditional television has been consumer confusion stemming from the different standards and resolutions, such as 1080i, 1080p, and 720p. Complicating the matter have been the changes in television connections from component video, to DVI, then to HDMI. Finally, the HD-DVD vs. Blu-ray Disc high definition storage format war engenders even more animosity for consumers. The confusion has led to slower uptake of the technology as many people wait to see what becomes the "ultimate" de-facto standard.
Great Toshiba HDTV (High Definition Televisions) on Amazon!
All about HDTVs ...
Find fantastic bargains on Toshiba HDTVs right here at Amazon.com!
Toshiba REGZA 32LV67U 32-Inch LCD HDTV with DVD Player
Amazon Price: (as of 09/07/2008)
Toshiba REGZA 37HL67 37-Inch 720p LCD HDTV
Amazon Price: $1,069.64 (as of 09/07/2008)
Toshiba REGZA 47HL167 47-Inch 1080p LCD HDTV
Amazon Price: (as of 09/07/2008)
Toshiba REGZA 42HL167 42-Inch 1080p LCD HDTV
Amazon Price: $3,639.99 (as of 09/07/2008)
Toshiba 23HLV87 23-Inch LCD HDTV with DVD Player
Amazon Price: (as of 09/07/2008)
Contemporary Systems!
All about HDTV ...
Besides an HD-ready television set, other equipment is needed to view HD television. Cable-ready TV sets can display HD content without using an external box. They have a card slot for inserting a CableCARD.High-definition image sources include terrestrial broadcast, direct broadcast satellite, digital cable, high definition discs (BD and HD DVD), internet downloads and the latest generation of video game consoles.
Other Brand Name, Quality HDTV (High Definition Televisions) on Amazon!
All about HDTVs ...
Find fantastic bargains on Brand Name HDTVs right here at Amazon.com!
Philips 19PFL5422D 19-Inch LCD HDTV
Amazon Price: $599.99 (as of 09/07/2008)
Mitsubishi WD-73733 73-Inch 1080p DLP HDTV
Amazon Price: (as of 09/07/2008)
Sylvania LD-155SL8 15-Inch LCD HDTV with Built-In DVD Player
Amazon Price: (as of 09/07/2008)
Pioneer PDP-5080HD 50-Inch 720p Plasma HDTV
Amazon Price: (as of 09/07/2008)
LG 37LB5DF 37-inch 1080p LCD HDTV
Amazon Price: (as of 09/07/2008)
HDTV Recording and Compression!
All about HDTVs ...
HDTV can be recorded to D-VHS (Data-VHS), W-VHS (analog only), to an HDTV-capable digital video recorder (for example DirecTV's high-definition Digital video recorder, Sky HD's set-top box, Dish Network's VIP 622 or VIP 722 high-definition Digital video recorder receivers, or TiVo's Series 3 or HD recorders), or an HDTV-ready HTPC. Some cable boxes are capable of receiving or recording two broadcasts at a time in HDTV format, and HDTV programming, some free, some for a fee, can be played back with the cable company's on-demand feature. 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.In the United States, as part of the FCC's "plug and play" agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with "functional" Firewire (IEEE 1394) upon request. None of the direct broadcast satellite providers have offered this feature on any of their supported boxes, but some cable TV companies have. 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 duplication of content or simply limit the number of copies permitted, thus effectively denying most if not all fair use of the content.
Great "HDTV Accessories" stuff on Amazon!
All about HDTV accessory ...
Find the best prices on HDTV Accessories right here from Amazon.com!
Geforce 8400GS Pcie 256MB DDR2 3PORTS Dvi Tv Out VGA DX10 HDtv
The MSI NX8400GS Series includes various state-of- more...0 points
VisionTek Radeon X1300 256MB PCI (VGA, DVI-I, TV-Out, HDTV)
Step-up to serious 3D performance and high-definit more...0 points
Multi Directional HDtv Antenna
Although the DB2 was originally designed for outdo more...0 points
Multi Directional HDtv Antenna
The DB4 has become our most popular model because more...0 points
Amplified HDtv Antenna with J-mo
As high-definition television (HDTV) becomes more more...0 points
Uni-directional Antenna
This high performance UHF antenna has a higher gai more...0 points
Cables To Go - 29641 - 6ft Ultima HD15M to 3 RCA HDTV Component Video Breakout Cable
Ultima HDTV Video Cables from Cables To Go are spe more...0 points
Avermedia HDTV MCE A180 whitebox MTVHDA18
AVerMedia AVerTVHD MCE A180 is a full height PCI A more...0 points
106IN Diagonal Accuscreens HDtv Manual Wall Ceiling 52X92IN
The AccuScreen Manual Screen is a sleek and attrac more...0 points
PNY Geforce 6200 256MB Agp VGA Dvi Svid HDtv Breakout Pod
With the NVIDIA GeForce 6200 you can leave the dar more...0 points
VisionTek Radeon X1650PRO 512MB Agp Dual Dvi-i Tv/hdtv Out
The VisionTek X1650 PRO is designed to deliver out more...0 points
106IN Model B Manual Pull Down Screen Matte White 16X9
The Model B wall screen is perfect for classroom a more...0 points
ADS Tech HDTV PCI card ( PTV-380-EF )
The PYRO 1394 Drive Kit includes PYRO 1394 Drive E more...0 points
106IN Diagonal Accuscreens HDtv Fixed Soundscreen Gray
The AccuScreen Fixed Screen is an attractive addit more...0 points
82IN Diagonal Accuscreens HDtv Fixed Soundscreen Matt White
The AccuScreen Fixed Screen is an attractive addit more...0 points
Ez-electric/motorized Projector Screen 92 Diag. 169/HDTV format Viewing Size 45X
Elite Screens is a company specializing in project more...0 points
106IN Diagonal Accuscreens HDtv Fixed Soundscreen Matt White
The AccuScreen Fixed Screen is an attractive addit more...0 points
66.5IN Diagonal Piper Portable Projection Screen HDtv Matt White
Draper Piper is a lightweight portable screen with more...0 points