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Wed, 05 May 2004

Hype Definition
Thinking about "Hi Def"? Think again... but at least the "monitors" sold today are not the issue.

Resolutions and Aspect Ratios

Since NTSC is analog, various TVs will display different screen resolutions. NTSC overscan is actually 736x482, but your TV will likely crop the outer edges of this, depending on model year, technology, and quality. The aspect ratio is 4x3 or 1.33:1. This makes almost a square box, slightly rectangle. In broadcast NTSC, audio is typically FM stereo, with the option of lower quality, secondary audio carriers.

Film is usually sported in two major formats, 1.85:1 or 2.35:1. Film does not have a particular resolution in pixels, but film grain generally limits this from being infinite.

Current digital televisions (DTV's) use the aspect ratio of 16x9 or 1.78:1. The digital transmission actually has tons of different video modes, and is called ATSC. ATSC can contain mutiple video "streams", data payload, TV schedule information, and several different audio modes encoded in AC3. These audio modes can provide either surround sound (5.1-like experience), stereo, or mono.

ATSC uses VSB for transmission. Originally, OFDM was to be used, but this was changed for some reason. OFDM would have given HDTV resistance to multipath, and actually make reception in most areas possible. The Europeans will be using OFDM. Instead, VSB cuts our broadcast tower range (compared to analog services) in half or perhaps by 2/3's, depending on the antenna technology employed.

VSB comes in two flavors, "terrestrial rate" and "high rate". "terrestrial rate" is 19.36Mbps and uses 8 level VSB (8VSB). "high rate" transmits at 38.57Mbps using 16 levels (16VSB). Currently, no broadcast transmissions use the higher 16VSB rate.

ATSC Resolutions
Resolution in Pixels Frame Rate Aspect
VerticalHorizontal 23.97624 29.973059.94 60 4:3 16:9
480i 640 X X X
480p 640 X X X X X X X
480i 704 X X X X
480p 704 X X X X X X X X
720p 1280 X X X X X X X
1080i 1920 X X X
1080p 1920 X X X X X

While these resolutions and aspect ratios are quite impressive, our cool new digital televisions will still letterbox some movies shot in 2.35:1. But a lot of movies are shot in 1.85:1 -- thats close enough to 1.78:1 to where it is expanded to fill the entire screen (!)

Digital Television vs. High Definition

While Digital Television brings us a lot of different modes, some are considered "high definition" and others are just considered "digital television". 720p and 1080i are considered true, high definition. 480p and 480i are considered "digital television".

720p vs 1080i and your television

While the mode 1920x1080i is my favorite mode, some claim (the inferior) mode 1280x720p is better. Either way, before you decide what side you are on, keep in mind that a vast majority of broadcasters have adopted 1080i. Make sure your TV supports at least 1080i. Your TV will still be able to view "720p", even if it has to scale it up to fit your television's 1080i native resolution. Some will do 720p and 1080i. Some televisions just display 720p. I would stay away from the 720p-only televisions, even at their discounted price. You are only robbing yourself of higher modes.

Also be careful of some displays, including some plasmas and LCD's. Keep on eye on their native resolutions -- some will not display anywhere near the 720p and 1080i sizes and downscale.

HDTV Content Delivery

Content delivery is still a sticky issue, as service providers scramble for bandwidth. Even with better compression systems available (mpeg4) HDTV channels require the bandwidth of 5-10 regular television channels.

Over the Air

A lot of stations have brought digital 8VSB stations on the air already. Some operate at high power, others do not. Most of it is a digital version of the 640x480 interlaced content we see on TV today...with the exception of some prime time TV shows and movies. Sick of those black bars on your analog TV -- wait until you see most of your content with black pilars on the side! Some channels are providing "HDTV" content in 703x480, in "widescreen" or 16x9 ratio. To receive over the air broadcasts, you must purchase a special HD decoder box. Most HDTVs are monitors -- meaning they have no HDTV tuners and require a video input.

Satellite

Satellite providers provide 4-5 network-like programming. HDNet, DiscoveryHD, ESPNHD, HDNetMovies, HBOHD, and ShowtimeHD are only available. Some satellite providers offer 1-2 pay per view channels in HD, and some provide CBS HD for rural areas without CBS (most markets have a black out on this feed). No local channels provided. The rest of the channels are 480p or 480i. You must also have a special HD receiver and HD subscription in order to receive content.

One thing to note is the satellite provider "Voom". They have several (obscure, completely no name) networks that are unique to their system. If these channels interest you, it is worth taking a look. Currently, they provide the most channelage available on any TV distribution system. Keep in mind that most of it is no-name content on no-name channels (aka, filler content). So if you really want 24 hours of clay animation in 1080i on the claymation channel, or are interested in their 24 hour tennis HD channel, go right ahead.

Cable

Cable offerings are similar to satellite, but usually offer something called InHD, which is similar to HDNet. Some cable companies are either offering a couple local HD channels (not all). The rest of the channels are 480p or 480i. You must have an HD receiver and HD subscription in order to receive content.

DVD

This is a content delivery system too, even though it is not broadcast. Although some widescreen DVDs will look nice on your new TV, keep in mind it is all 703x480 content. Make sure you purchase discs with 1.85:1 ratios so it fills your screen, 2.35:1 will still be letterboxed slightly. You may also want to invest in a progressive scan player (they output 480p to 530p progressive signals). While a lot of movies are captured in progressive these days, some are not and will be interlaced on a progressive screen! High definition DVD does not yet exist.

Video Game Consoles

The only video game system that provides high definition output is the XBox. The rest are either 480p or 480i. Most XBox titles do not support 720p or 1080i unless specifically stated. The HDTV box checked usually means the title is available in widescreen, 480p.

DVR's

There are a couple of DVR products out there that support HD recording. Dish network offers the PVR921.

HDTV Content

Delivery systems aside, there is simply a lack of actual content. A lot is upconverted garbage and is the television equivlent of going into photoshop, taking 640x480 image from a 1/2 megapixel camera, scaling it to 1920x1080, and calling it a "2.0 megapixel image".

The major networks (ABC, NBC, etc) and the HDTV cable/sat channels mentioned above are the only content providers of HDTV programming. While the specialized cable/sat channels broadcast HDTV (1080i) all day, Networks typically only kick in on HD during the evenings. As demand grows, more and more shows will be shot in HD -- or film transfered to HD.

While HD shows sometimes display in letterbox (black bars) on an analog TV, we get something worse: most of our content has two black pillars on each side! A lot of advertisements and shows that are in "wide screen" actually are letterboxed and black barred. Perhaps pretend HDTV/widescreen content helps brand image?

Broadcast TV Networks and Modes
NetworkModeNotes
ABC720pPrimetime Only, Primetime Movies
NBC1080iPrimetime Only
CBS1080iPrimetime Only
FOX480p480p widescreen, 720p "someday"
WB1080iVery little content
UPN1080iVery little content
PBS1080i, 480iHealthy amount of content, multiple streams
TBN480Unknown Status
PAX480Unknown Status

Hype Definition Offenders

Not to pick on anyone in particular, but here are some upscaling offenders:

ESPNHD

This is typically 703x480i 4:3 interlaced video upscaled to 1920x1080i and squashed to 16:9. It ends up being a bunch of blury fat people running around -- not even in the right aspect ratio. This channel is outright embarrassing...but ESPN is gearing up for HD and may provide some better content in the next year.

FOX

FOX claims to be in high definition. Its actually 480p in widescreen.

CBS

CBS has done a pretty good job at keeping us entertained with 1080i TV shows. During prime time, CBS plays special sequences during advertisements on their HD channel. "You are watching CBS in HDTV" is repeated over and over. The one in particular that is funny is the "CBS HD Sports", where all the sequences featured are actually 4:3 video upscaled (and squashed) to 16:9. I am sure CBS plans to offer sporting content soon, but this is pathetic.

Video shot in HD but shown on channels that do not have any HD distribution

A lot of channels (typically cable or satellite) that do not have any means to distribute high definition are airing wide-screen, letterboxed content. What is the point of this? The HD viewer has two choices at this point: Zoom in to the 640x480i video to fill the screen with blury video or enjoy the show/advertisement in black picture frame mode (or black horizontal and vertical bars).

Local News Casts in HD

We have one station in particular (KING 5, Seattle) that brags about its HDTV news broadcast. They forget to inform their viewers that they couldn't actually afford more than one HDTV camera in the newsroom (out of 3-4), so be prepared to switch resolutions a million times during the news broadcast.

Local TV Shows in HD

While Evening Magazine (King 5 local "HD" content) does occasionally air some sequences in 1080i, a majority of their episodes are upscaled 480i. What is worse is that conventional, analog TV users are forced to watch this show in black bar widescreen format.

HDTV sounds awful, should I even bother?

Consumers should realize that there is only little content available in HDTV. Buying that $5000 plasma screen will not improve the clarity and resolution of all your cable and satellite channels. Some people may choose to wait, but if you are in the market for a new TV, I would definately give the lower end models (<$2000 or <$1500) a very close look. It will still be a very long time before one can purchase an HDTV set for the price range of traditional televisions, so it may not be for everyone.

HDTV is a double edged sword.....while a good 1920x1080 television program will take your breath away, you will puke once you are forced to watch something in 640x480 afterwards.

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XBox in HD
In the mix of hype, the XBox is the only game console that actually has "High Definition" output. Amazingly, the adapter (which features component output and optical 5.1 out), is a mere $19.95. I am used to being ripped off because I happened to buy recent technology.

Available Games

The labeling on XBox games are becoming a little more standardized, but they are little help. Some say "HDTV", but you have to be careful with this one. Most that don't display a specific mode like 720p or 1080i are just merely a 480p (480 lines, progressive scan) in "wide screen".

I bought Enter The Matrix, since it did advertise a mode of 1080i. It turns out, yes, it is in 1080i, but the textures were drawn for standard resolution.

GTA 3 and Vice City are in "HDTV", but in reality, its just 640x480p in 16:9 (widescreen) mode. This keeps my TV from burning in, but does not really provide me with any display enhancement.

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