or "Things They May Not Tell You in the Store"
by Steve Puffenberger, Advent Media, Inc.

After all these years it's finally here. The fuzzy old idiot box will give way to the new supersharp high definition idiot box - or in most cases idiot panel - as the old NTSC broadcasting has been permentally switched over to the new Digital ATSC standard.

I subtitle this "things they may not tell you in the store" not because the sales geeks are idiots or deceptive, but it's such a complex topic it's impossible to explain in a 10 minute store conversation when you're trying to analyze the relative merits of the different TVs.

You've probably heard the warnings on all the TV stations. If you watch TV over the air, you will need a converter box to keep an old fashioned TV running, as their tuners won't work at all, except for a few low power stations that are exempt from the transition (of which there is one in Columbus.) But chances are you're looking for recession-driven bargains on a new flat panel TV, and when you get it home it doesn't look quite right. Just like the new car you bought that has 73 more buttons on the radio than you're used to, HDTV has a learning curve. It's not a simple "plug and go" situation.

Before we get into hookup and operation details, we'll start with the terms we use in the HDTV world.

DEFINITIONS

ANALOG = The "old" method of broadcasting which uses varying voltages to create a signal analogous to the original image - really not that much different from the way an old vinyl record captures sound in a wiggling groove.

HDTV = High Definition Television - widescreen TV that's higher in resolution than SD

SDTV or just SD = Standard Definition Television - narrow-screen (standard) TV that we've always had

DTV = Digital Television - SD or HD television that is transmitted with 1s and 0s instead of analog signals

NTSC = the old "standard" by which television signals were broadcast, developed by the National Television Standards Committee (aka "Never Twice the Same Color") There is only one NTSC standard, used in North America, Japan, and a few other US-aligned nations; in Europe the standard they used is called PAL.

ATSC = the NEW "standard(s)" by which television signals are broadcast, from the Advanced Television Systems Committee. (www.atsc.org)

Pixel = "Picture Element" Unlike analog TV which uses continuously varying voltages on "raster lines" that are scanned on a tube, (see my long article on this here) digital TV uses a fixed number of pixels that work just like the pixels in digital photography. You can see the individual squares of color if you look at your display really closely. For the sharpest display you need to MATCH the pixels of the display to the pixels of the signal. Otherwise the system has to interpolate - or map pixels, and that always results in artifacts (subtle odd things that you shouldn't be seeing). Read more on artifacts below.

Frame Rate = You know that film and television work by flashing sequential images so fast that your eye perceives them as motion. NTSC and now ATSC video in the US use a frame rate of 30 frames per second. (In Europe they still use 25 FPS.) A bit of history: 30 was used because it was easy to sync to the 60 Hz (cycle per second) power grid before the days of crystal control. And in Europe they used 25 because of their 50Hz power. Movie theaters still use 24 frames per second. Converting that to video is always a trick.

HDTV 720p or 1080i, or 1080p. Unlike SDTV, HD comes in three different flavors (and DTV comes in four). The numbers have to do with pixel counts of the display.

• 720p has a raster size of 1280x720 pixels
• 1080i and
• 1080p have a raster size of 1920x1080 pixels<
• And digital SD signals have a raster size of 720x480 pixels.

You can see why HDTV gives such a superior picture

The "P" means "progressive" where the frame is drawn from top to bottom of the screen all at once, as a computer screen does

The "I" means "interlaced" where half the frame is drawn first, then the other half in alternating rows of pixels, just the way old fashioned NTSC video has always done it.

(FWIW the HDTV standard include digital cinema resolutions of 2000 and 4000 pixels! See them at your local digital movie house!)

CODEC = COmpressor/DECompressor. ;All broadcast video has to be compressed in one way or another. If you do the math, which I won't get into here, there's just too much data for the transmission systems to handle. But when you compress video you actually "throw away" data and the receiver has to guess as to what the thrown away data was and reconstruct it for you. So on your new HDTV, even in HD, don't be surprised if some things look odd.

Some of the compression methods work better than others for different content, so the ATSC committee decided to be "inclusive", and gave us a smorgasbord of options for broadcasters to choose - making it much more complicated for the rest of us.

ANALOG CABLE = This is the Cable TV (CATV) we're all used to. The cable provider "multiplexes" (combines) all the channels you can receive and sends them down the cable in a way that resembles the signal your antenna would pick up - only with a lot more channels. Your TV's tuner chooses which channel to display internally, and no feedback is sent back to the cable provider. With older premium CATV which required a cable box, the cable provider scrambled certain channels, and the cable box descrambled them for display, but all channels are present on the wire all the time. These cable boxes could send feedback to the CATV provider for pay-per-view billing purposes.

DIGITAL CABLE = The new way of providing digital television over the same CATV system is quite different. Instead of supplying all the signals at once and letting your TV choose, the digital cable box establishes a computer connection with the CATV company's server. Your box sends a request to the CATV provider's digital server for the channel you want to watch. The server then sends a single stream of digital video (which could be HD or SD) to your cable box. The box transcodes it to either analog video for an older TV, or digital signal for a new display. This one-at-a-time scheme makes HD possible because multiplexing HD channels would use more bandwidth than possible with existing cable infrastructure. It allows the cable provider to maintain analog cable service, offer "DVR" (digital video recording) on their server, and "on demand" services. It also provides Digital Rights Management (DRM) for content producers, as HD digital signals cannot be recorded locally. Finally, the cable company can log what you're watching. This is also how satellite and telephone company TV works.

Enough of the terms. Now on to hooking up that new HDTV

CONNECTING YOUR SET FOR HD RECEPTION

OVER THE AIR DTV BROADCAST

For a long time local stations have been broadcasting in DTV, both HD and SD. You will need a UHF antenna to pick up the signals, because DTV is all on the old UHF band. The old VHF band (channels 2-13) is being handed back to the FCC for cell phones and fire/police emergency radios. (Some of the UHF band is also being handed back, meaning wireless microphones and walkie-talkies operating in the 700Mhz band will now be illegal. Verizon has leased this band for expanded cell phone coverage.)

The "Digital Transition" as it's been called is also a political football. For years it was scheduled to occur on Feb 19, 2009, but Democrat politicians did not think their consitituents were ready for their old TVs to go silent. So they extended the deadline to June, 2009, much to the consternation of broadcasters who have to maintain parallel transmission systems (at the cost of multiple tons of C02). Finally in June of 2009 the transition took place but not without going into overtime in a game of political football.

If you are using an anntena to receive TV and you lose your signal, your TV will either report "no signal available" or you may see the picture freeze or show up in blocks instead of snow. Move your antenna around or get it near a window and you should see a picture.

The other thing to note for on-air DTV broadcast, is that broadcasters can now add extra channels to their DTV signals. In Columbus, Channel 4 has a retro channel on 4-2; Channel 6 runs a movie channel on 6-2, and PBS Channel 34 has 4 extra streams they broadcast. When you scan channels during TV setup, be sure you enable these extra channels if you want to see them. (Digital cable does NOT carry most of them.)

CONNECTING TO BASIC CABLE (WITHOUT A DIGITAL CABLE BOX)

You'll still receive TV on your old set if you have basic cable. At least for now, that is. At some time in the future cable companies will want to move over to DTV to increase bandwidth on their wires, but for now you're OK. You can keep old sets on the cables throughout your house and continue to use them. The difference is that the cable companies will be transcoding the HD signals from the broadcasters to SD so your regular TVs can accept them. (Before, the cable companies just passed them through.) Appreciate your cable company or satellite provider: they've had to spend millions to provide this service!

But if you have a new HDTV and you connect it to your standard cable (becauase you're too cheap to pony up for digital cable or HD satellite TV), be prepared for a big surprise. Sure you can do that but the SD signal will look awful! I mean really bad. Not only is the HD signal downsampled to SD, inducing artifacts, but your TV will then try to fill the screen with the SD signal, making all the imperfections of analog TV look worse than on an old fashioned CRT! And that's regardless of whether you have a DLP, LCD or Plasma display. (The only way around this is to use a high definition CRT set, but the last I looked there were none in the stores.)

But it IS possible to watch SD cable and also connect an antenna and watch local broadcast in HD, though this is getting tricky.

Older HDTVs had two tuners with two separate antenna connections. One is for ATSC (the HD antenna - see above) and the other for NTSC (the SD antenna or cable). If you're lucky enough to have one of those sets, you can watch HD over the air and get the SD cable stations by cable. Your TV's tuner will interleave the stations in the channel scan so it's easy to switch. You'll know you're on HD when the picture looks good! (SD on an HDTV looks really bad!)

But (and it seems there always is a "but" in HDTV land), newer HDTVs only have ONE antenna connection. Logically so, since soon NTSC video will be a thing of the past. But it creates a problem when trying to be cheap. So you have these options if you don't want to switch to digital cable or HD satellite:

1. Throw in the towel and watch fuzzy SDTV on your new HD set
2. Dump cable altogether and watch local broadcast
3. Connect the cable to your old VCR, and use it as the tuner to watch the cable stations. You'll connect the VCR with the LINE inputs (video/audio, generally yellow, red & black plugs). Then you'll have to switch input each time you want to change to HD or cable.
4. The expensive solution is to use a Media Center PC (Windows XP Media Center Edition, Windows Vista Home Premium - Ultimate and Windows 7 Home Premium - Professional - Ultimate) as a signal source. You would need a really fast computer that has a tuner card with both NTSC and ATSC antenna, and a high quality video card with DVI or HDMI connections. Then you would use Windows Media Center as your entertainment source. This way the PC will work as a Digital Video Recorder (DVR) for time shifting.

Or give up and subscribe to digital cable or satellite. Resistance is futile.

CONNECTING TO DIGITAL CABLE OR HD SATELLITE TV

If you use a cable or satellite TV box, you're used to using a cable box instead of the TV's tuner. But if you're still connecting your cable box to your TV with an antenna wire, tuning the TV to channel 3, all that's going to change. You can't get HDTV that way.

First realize that not all cable boxes are HD ready! You need to subscribe to an HD cable or satellite service, and they'll need to provide you with an HD cable box. If the box (or your bill) does not say HD - it will not work. Contact your service provider for a new box. You'll also need some very expensive cables to go from the box to the TV.

There are two types of hookup cables your box may support, and you'll have to look at your cable box to determine which one to use.

The older type is called a "component" cable. It is actually a bundle of cables that have a separate wire with Red, Green, Blue, Black and White plugs - 5 in all. You'll have an output on the box that says "Component" and a similar input on the HDTV. Just connect the colors to the appropriate plugs, then switch to the "Component" input on your HDTV.

The newer cable is called HDMI. It's a single cable with a flat blade sort of plug, which carries digital signals to your TV, including audio, so there's just one connection from the cable box to the TV. (More importantly, HDMI allows Digital Rights Management - DRM - to confirm that you're not copying the program, as some programming will not display without DRM certification.) Once connected, switch the input of your TV to "HDMI" and you should see TV.

Both the cables are quite expensive, and you'll need one that's long enough to go from the cable box to the TV, and if the TV is hanging on the wall, fishing it through the wall could be complicated. (If you're installing a home theater, insist that the cables be placed in conduit so when the "next big thing" comes along, they're easy to replace!)

THE CABLE/SATELLITE BOX DILEMMA

The problem with digital cable (which includes telephone-line TV or satellite TV as well as digital cable) is that you must have a box connected to every HDTV in your house. Because digital cable makes a 1:1 connection with the server, you can no longer just add a splitter and branch off to TVs in the bedroom or basement. Each HD set must have its own box.

With cable or satellite, you can add as many boxes as you like, but if you use the new service from the phone company that brings in TV over the phone lines, you can only see 2 HD streams at once. That means you need to carefully consider how you will use HDTV in the future before you respond to the low-price switchover offer.

(Remember that with digital cable, the cable companies are continuing to supply their analog signal, so you can use your existing analog TVs with the splitters and other wiring you already have. Nothing will change for analog cable.)

CONNECTING DVD / VCR / BLU-RAY

The other components you may have can connect to the TV through the standard line inputs. Because VHS and DVD are both SD signals, you may just want to keep your old TV around to watch, because they will look better. But if you use the best quality connection (which may mean buying more cables), you can get good results from DVD, and especially Blu-Ray.

In order of quality (least to best) here are the types of connections to look for:

• RF: Some people are still connecting their VCRs to the TV using the antenna connection and tuning to channel 3. You can't do that with HDTV, so don't even try. For a standard VHS VCR you'll need to use Composite.
• COMPOSITE: This means all 3 of the components of the analog TV signal are put on one wire - the yellow one, and it yields the 2nd worst analog signal (2nd only to RF). The 3 plugs that make up a composite cable are Video and Left Right audio, usually with yellow, red and black (sometimes white) plugs. The yellow is for video, red is right audio and black is left audio. Some really old VCRs will only have one audio plug, for mono audio.
• S-VIDEO: When they invented S-video they took the color components away from the black & white component and sent them down two wires in one cable. Thus the S-video signal gives you a better look than a composite signal. You will need an S-video cable (has a round plug with four little pins), and a separate audio cable with left and right audio plugs.
• COMPONENT: There are actually three components to an analog video signal, and this kind of connection keeps them on 3 distinct wires so there's no interference. This is the best analog signal there is. You will have 3 wires for video and two for audio. You can connect cable boxes, DVD players and Blu-Ray HD disk players with component. (Note that some Blu-Ray titles may not play with a component hookup because of a missing DRM connection.)
• COMPUTER - VGA or DVI:These are two interfaces used to connect to a computer. Nothing else has those plugs. VGA uses a 15 pin connector, rectangular with angled sides so the plug only fits one way. DVI has more pins (some may be missing), and a blade on one end so it only fits one way. VGA provides analog component video much like the component connections (above), and DVI provides digital video, similar to HDMI (below). Neither include audio so if you use audio from a computer it has to be connected separately. (DVI does not do DRM, so some titles may not play without HDMI.)
• HDMI: The HDMI delivers a digital signal to your TV, and the only peripherals you'll find with one of those are BluRay HD disk players and computers. All it takes is one cable to hook up video, sound and Digital Rights Management.

THE HD EXPERIENCE

Once you get properly hooked up and those pristine HD signals show up on that huge flat panel, you'll be saying "wow." You won't believe the detail in the landscapes, the wrinkles in the actors, or the dust on the set. It's all there. But before long you might start to notice that some things don't look quite right. Those are digital artifacts, and you're just going to have to get used to them. Here are what to look for: the problems aren't in your set - they're in the system.

MOTION ARTIFACTS

I first noticed this at the Olympics a few years ago. A diver about to dive. The crowd behind is crystal clear. Everything is spotless. Then the diver leaps in the air and the camera tilts to follow. As the diver spins he turns into blocks of color, and as the camera tracks him, the crowd in the stands behind turn to more tiny blocks of color. All detail is lost and all you see is colors that look sort of like what the image should be.

These are called motion artifacts, and are the first kind of compression artifact we'll discuss. You know that the broadcaster is sending 30 pictures every second. In the old days, that's what really happened. You would see 30 frames (actually 60 "fields") each second, and a full field of information was drawn on the screen with each scan. Not anymore. Broadcast HDTV uses a codec called MPEG-2. It actually sends a full frame only TWO times a second! That's right the full picture is only sent twice a second, known as an "I" frame (to impress your friends.) In between are "P" frames and "B" frames that are derived from different calculations to predict what the image should be from one frame to the next. In essence, they contain data for what has changed between the two I frames.

Bottom line, when there is a lot of movement from one frame to the next (like the camera quickly moving with a spinning diver), the system doesn't have enough information to guess what the next frame will be, so you'll see these blocks of color (called macroblocks - impress your friends again).

Here's an interesting anamoly. I was watching a football play. The quarterback threw a pass and the camera tracked the ball. When the receiver caught the ball, the camera seemed to keep panning for a split second, then snapped back to center on the player who caught the ball. That was because the motion intelligence of the stream thought the shot was going to continue to pan, but on the next I-frame the action was stopped, so it appeared to snap backwards. It just looks a little odd.

This is where the broadcasters have made choices between the two common broadcast standards of 720p and 1080i. Both have to squeeze the signal into the same "bandwidth" CBS and NBC have chosen the 1080i standard. The 1080i transmits a lot more pixels than 720, so the amount of data in the P and B frames is less, meaning 1080 has more motion artifact than 720. ABC and FOX broadcast use 720p. 720p seems to work better on sporting events or other live action shows with lots of motion. 1080i works well on film-based movies or dramatic shows because of the frame rate conversion. 24 to 30 fps is accomplished by the "3-2 Pulldown" method which uses fields to even out the change in frame rate. (Impress your friends with that piece of trivia!)

Blu-Ray Disk uses 1080p. By being progressive, and having more bandwidth on the BD media, the motion artifacts are minimized.)

COMPRESSION ARTIFACTS

There may be times when you're looking at a high contrast image (like white type on a black background) and you'll see sparkly effects around the edges. This is a compression artifact just the same as you'll see with a highly compressed JPEG image from your digital camera - only they sparkle because they change every frame. (Sometimes you'll see them change twice a second - see above to know why). HD video combines both motion compression with still image compression to squeeze everything into the bandwidth. Still image compression works by throwing away pixels and storing a mathematical formula to recombine them. The higher the compression the more it throws away and the less accurate the reconstruction is. This is most apparent when there is high contrast. Combined with the motion artifacts this can sometimes make for a very messy picture.

SCALING ARTIFACTS

Because there are two HDTV standards, and the flat panel has one fixed resolution (unlike CRTs which can adjust scan frequency), you can't get away from scaling. If you have a 1080p display and you watch a 720p station, your TV has to scale the image up to fill the screen. If you have a 720p display and watch a 1080 station, your TV has to scale the image down. And if you watch SD (480i) from cable, DVD or VCR, it will have to scale up too.

And even if you have a 1080 display and are watching a 1080 station, most TVs are set by default to overscan, meaning that even those stations get their display scaled. (You can correct that by using the Aspect control to choose 1:1 pixel mapping. See below.)

Scaling remaps pixels so the picture fills the screen. But in so doing, the scaling circuit has to make compromises since nothing matches. The borders of the source pixels will fall in between some of the display pixels, and you'll see scaling artifacts, which are generally a fuzzy appearance.

Unless you're looking really carefully, you should not see much scaling artifact between 1080 or 720 broadcast on your HDTV, regardless of which one you have.

But if you're displaying SD television on your flat screen, you're in for a shock. As I said earlier, the picture will look REALLY bad because it's scaling the 720x480 pixels up to at least 1280x720. Pixels get big and they don't match, so the circuitry guesses on how to display them, creating jaggy edges for anything that's not horizontal or vertical. Then the display applies a circuit called "anti-aliasing" to smooth out the rough edges. The result is a softening of the picture so it looks really fuzzy up close. From far away it won't look too bad, but up close it's a problem. There's really nothing you can do about fuzzy SD on an HDTV, other than going back to your old TV.

The other issue with SDTV is that it's not widescreen! Most TVs will try to stretch the picture so it fills the screen, but that makes everyone look fat. Either on your TVs remote or in its menu you'll find an "aspect" control that allows you to control the way the TV handles 4x3 "narrow" screen signals. The options usually are:

• Stretch - which stretches the picture across the whole screen
• Smart Stretch - a feature on some TVs that keeps the center 1/3 of the picture normally scaled, but stretches the sides to fill the screen.It works well for static stuff, but when the camera pans it can make you dizzy
• Pillarbox - which frames the 4x3 image at the proper ratio, leaving black "pillars" to the left and right, and...
• "Zoom" - which keeps the image properly scaled, but blows it up to fill the screen side-to-side, cropping the top and bottom. (This is the best way to watch "letterboxed" content that has black top and bottom of the 4x3 narrow frame.)

You'll need to find the aspect control and learn to use it, since program content can vary (and now this gets really complicated).

DVD SCALING

If you're watching SD cable or broadcast, VCR or "full screen" DVD you'll want to choose "smart stretch" or "pillarbox" for normal 4x3 programming. If the SD program is letterboxed, you can use "zoom" to see it full screen, though it's about half the normal resolution.

If you're watching a widescreen DVD it's another ballgame called "anamorphic" video. The anamorphic process was created for Cinemascope long ago, but they decided to make widescreen movies stretch across the whole 4x3 720x480 raster of the SD frame to get more quality. In your DVD player you will find a setting that tells it what kind of TV you have. If you had an old 4x3 set, you'll need to change it to widescreen or 16x9. That will allow the player to send a squeezed picture to your TV. Everyone will look tall and skinny if you watch it on a regular TV. Then in your HDTV you need to choose the "Stretch" mode from the aspect menu to stretch the screen back out to where it belongs. Because it uses the full raster of the SD frame, widescreen DVDs will look better than SD broadcast on the HDTV, even though they're not truly HD.

Of course when you are done watching the DVD and switch back to SD broadcast, everyone will look fat and squatty, until you switch the aspect back to where it was. Get to know your Aspect control. You'll be using it a lot!

COMPUTER DISPLAY

Computer displays are another story altogether. If you hook a computer up to your HDTV, either to browse the Internet, make a presentation or use your Media Center PC as an entertainment or gaming source, resolution is critical. You need to know what the true "Native Resolution" of your panel is, then set your computer accordingly. Choices usually are 1280x720, 1344x768, 1440x800, or 1920x1080. (In rare cases you'll find other odd resolutions. Refer to your display's documentation.)

Additionally, the display hardware in your computer will need to support the chosen resolution. Older computers need not apply! If the video card is more than 2 years old, chances are it will not handle any of the HD widescreen resolutions, so you will need to at minimum replace the video card, or at worst buy a whole new computer. (Laptops cannot be upgraded.)

With a computer feed you will want to find one more setting on the display, the "Aspect" control. It's called "dot-by-dot" or "1:1." What it does is to map the computer pixel-per-pixel so you can see the whole screen, and that the pixels are sharp.

By default most HDTVs put computer displays in an "overscan" mode, and the edges of the computer display, including some controls, will extend off the screen. Text and other images will also look fuzzy because of the scaling artifact. Choosing 1:1 will snap the full screen into view while letting text and images look sharp and clear. (Choosing 1:1 for broadcast will also give you the sharpest picture.)

ENJOY THE FUTURE

This is all probably more than you ever wanted to know about HDTVs, but it just shows that the technological creep has come to your living room. Unless you're an expert, you'll not get the full benefit of the HDTV you've invested in. This is where our PainFree HD Video Services™ or PainFree Tech Services™ can help. If you have questions, need a video made that will work on HDTV sets, or just need someone to come and make sure your HD set is configured properly, give us a call, and we'll be happy to help.

Hopefully this article will answer most of the questions you have. If not there are ample resources on the Internet. But we're always ready to help. Give us a call, 614-538-1622, or click here to contact us!

The information provided in these articles is for informational purposes only
Make system changes at your own risk
The author assumes no responsibility for data loss or other damages
Articles may NOT be duplicated without permission
Trade names used are the property of their respective owners.