guess being able to pick out individual fans in the crowd during a wide - screen baseball - plot broadcast , or to see the intricate crosshatching of Martin Sheen ’s railroad tie as he addresses the nation during an episode ofThe West Wing . High Definition ( HD ) video assure such things — a broad field of view and much more image contingent . Whether you ’re concerned in watching , create , or just learning more about HD , now is a honest time to protrude paying attending — prices for the equipment necessary to watch and make HD content are fall . Here , we ’ll look at some of the technology behind HD ; in our December issue , we ’ll explore HD world on the Mac .
Formats Face Off
Standard NTSC ( National Television System Committee ) video has 720 horizontal pixels and 486 perpendicular pixels ( 480 upright pixels for pack together data format such as DV and MPEG-2 ) and has a frame charge per unit of 30 ( or , technically , 29.97 ) skeletal system per secondly . NTSC video is also interlaced — each TV frame is made up of two distinct TV landing field . The first field comprise the odd lines of an effigy ; the second , the even lines . The aspect proportion of NTSC , or Standard Definition ( SD ) , TVs is 4:3 .
At the gist of HD video is increased resolution . HD pushes the pixel count right smart up , most commonly to 1,280 by 720 pixels or 1,920 by 1,080 pixel . These HD character are usually referred to by vertical pixel count and whether frames are progressive or interlaced — for model , 720P data formatting or 1080i format . There are roughly 350,000 pixels usable in SD video recording ; HD expose more than 2 million — this is why the bite of HD video is startling . HD can have a kind of skeleton rate , but HD broadcast medium is usually 1080i at 30 fps or 720P at 60 fps . HD is also a wide - screen format , with a native view ratio of 16:9 . Watching HD feels like a movie - dramatics experience . HD signaling can also pass around using Dolby 5.1 - channel surroundings phone , the audio format used in most commercial-grade DVDs .
Keeping Watch
HD content currently shit up a very small pct of television broadcasts . But with HD connection picture such asAliasandLaw & Order , cable series such asSix Feet Under , and sports broadcasts such as ESPN baseball game and the Olympics from Athens , HDTVs are becoming more than expensive heart candy . you could receive HD signals , encoded as MPEG-2 streams , via satellite , digital cable , or ATSC digital broadcasts ( see “ What It Means : HD ” for a glossary of HD - related terms).Elgato’sEyeTV 500 ( $ 349 ) lets you watch , record book , and save ATSC HD broadcasts , and the EyeTV software program let you blue-pencil out commercials and undesirable fabric . you’re able to also downloadJohn Dalgliesh ’s free MMInputFamily number one wood , which allow Macs to work withDVICO’s$199 Fusion HDTV3 Gold PCI card to exhibit HD broadcasts . ( At this prison term , there ’s no agency to view HD satellite or digital - cable signals on your Mac . )
There are no HD DVDs yet , but the DVD Forum , which brought you today ’s DVD , has take in an HD DVD banner , which can employ H.264 / AVC ( Advanced Video Coding ) , Windows Media Video 9 ’s VC-9 technology , and MPEG 2 .
What It Means: HD
The world of modern telecasting is fill with confusing terms and unwieldy acronym . Our glossary will help oneself you sort it all out .
view Ratio : The balance ( width : stature ) of the look at area on a monitor or a goggle box screen . HD has a wide - screenland , 16:9 proportion . SD has a narrower ratio—4:3 .
ATSC : A digital - broadcasting standard developed by the Advanced Television System Committee ( also refers to DTV and high-definition television standards ) .
Digital TV ( DTV ): A television signal transmitted as digital entropy . HD television is digital , but not all digital broadcasts are HD .
Dolby Digital : Six - channel digital - audio standard , also called AC-3 or Digi - tal 5.1 .
heighten Definition TV ( EDTV ): A progressive Mount Rushmore State television that accepts the progressive yield of some DVD players . Usually , these TVs also have a First State - interlacer built - in . They are not HDTVs .
HDMI : High Definition Multimedia Interface — a digital connector .
HDTV - Ready : A TV that can display HD video recording if a freestanding HD decipherer box seat is impound .
MPEG-2 : Moving Picture Experts Group 2 . A video - compression format used to condense HD and SD video , for belittled data rates in videodisk and broadcast medium .
tellurian Broadcast : Traditional over - the - tune programme .
