DTV HDTV Satellite Cable
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Resolution: |
The number tri-colored pixels or dots. |
<left to right> x <top to bottom> |
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Aspect Ratio: |
The ratio of width vs. height. |
<units across>:<units down> |
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Refresh Rate: |
FPS or Frames Per Second (Hz). |
p=Progressive Scan or i=Interlaced |
ATSC digital and high definition standards for broadcast television have 18 formats. The 12 formats of DTV make use of a lower resolution comparable to NTSC analog television. A resolution of 640 pixels (dots) wide by 480 pixels (lines) high is available in progressive scan formats with refresh rates of 60, 30, and 24 FPS (frames per second). The 640 by 480 resolution is also available in a 60 frames per second interlaced, meaning half the horizontal scan lines (every other line) is pained on and then the other half are painted on. All four of the 640 by 480 standards are available only in the 4:3 aspect ratio same as that used by the NTSC analog television standard.
A slightly higher resolution of 704 by 480 pixels provides aspect ratios of both 4 by 3 and 16 by 9. These formats are available in 60, 30, and 24 FPS refresh rates with progressive scanning and 60 FPS with interlaced scanning. All eight of the possible 704 by 480 formats are standard definition.
Lines vs. dots. A true digital monitor with a DVI interface has just dots. A VGA style monitor has data sent to it serially in lines. The interlaced digital signal sends every other line at a time per frame, first the odd numbered lines then the even numbered lines. Progressive scan sends sends every line. But, interlaced is 60 FPS and Progressive is 30 FPS. These FPS values are an approximation. FPS is really something like 31.02...or 29 something.
True high definition signals are available in two resolutions and in six formats. All HDTV formats use the wide 16:9 aspect ratio. The first three HDTV formats provide resolutions of 1,280 pixels across by 720 pixels high all in progressive scan formats with refresh rates of 60, 30, and 24 FPS. The highest resolution HDTV format creates an image using 1,920 pixels across by 1,080 pixels high. This ultra-high resolution format is available in 30 and 24 FPS refresh rates using progressive scanning and 60 FPS using interlaced scanning. There are also plans to introduce a 60 FPS progressive scanning format of the 1,920 by 1,080 HDTV format 1080p when the technology is developed to sufficiently compress and deliver such a signal.
The two HDTV formats used by most US TV networks are 720p and 1080i. 1080p requires a wider bandwidth than is currently available.
All 18 current digital broadcast television formats have a number of elements in common. They all transmit signals in a digital format using a 24 bit binary code. Additionally, all the formats make use of a modification of the MPEG-2 compression algorithm for video and AC-3 digital sound for audio compression. The primary differences between standard definition digital televisions and high definition TVs are the resolution and aspect ratio.
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Resolution Pixels |
Aspect Ratio |
Refresh Rates FPS |
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1920 x 1080 (HDTV) |
16:9 |
*60p, 60i, 30p, 24p |
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1280 x 720 (EDTV)* |
16:9 |
60p, 30p, 24p |
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704 x 480 (DTV) |
16:9 |
60i, 60p, 30p, 24p |
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704 x 480 (DTV) |
4:3 |
60i, 60p, 30p, 24p |
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640 x 480 (DTV) |
4:3 |
60i, 60p, 30p, 24p |
720p = 1280 x 720, 16:9, 60p - EDTV
1080i = 1920 x 1080, 16:9, 60i - HDTV
* 1080p is not available through current broadcast standards.
* It must be noted that there is standard called enhanced definition (EDTV) format that incorporate the wide 16:9 ratio. The consumer may see this as high definition even though it truly is not.
HDTV signals at 60 FPS interlaced require approximately 19 megabits per second to carry all the necessary information to reproduce the video picture. This 19 MBits is achieved by compressing the pure signal through a special high definition subset of the MPEG-2 video compression algorithm and Dolby's AC-3 audio compression algorithm. In fact, the uncompressed HDTV streaming data is about sixty times larger than the compressed 19 MBits signal.
Each HDTV broadcaster has been allotted a 6 MHz frequency bandwidth for their HDTV broadcasts. A compressed 19 MBits HDTV signal fits into this allotted frequency band, the same bandwidth used for analog NTSC television signals. However, using a digital compression algorithm, the same bandwidth can carry a single 720p HDTV signal and multiple standard resolution DTV signals. Since a 640 by 480 resolution digital television signal is not as large as a 1,920 by 1,080 resolution signal, several of the smaller signals can supplant a single high definition signal. Thus, digital television allows broadcasters to provide multiple channels of standard quality programming (similar to the quality of a DVD) or a single channel of ultra-pure, ultra-high quality 1080i high definition programming.
The above describes the current technology of Digital TV. But regardless of the technology, most of us will continue with the old traditions of TV because we cannot see past our comfort zone. Example:
Do all TV monitors have to have tuners?
Today as was in the days of the BIG screen CRT/projection home (I an gulled by this term HOME) theater style systems, there seems to be a narrow requirement for superfluous options.
This next section is in response to a particular aspect of many articles about high-def monitor only devices, such as the NEC4000 40" 16:9 1280 x 720 LCD industrial monitor. This is more about the philosophy of TVs and monitors than it is about these particular monitors themselves. Yes, these are astonishing monitors, but they are very expensive, about $5000 for a 40".
What I am talking about is, in the videophile world of hi-def, the idea of an embedded tuner is…well repugnant. Why spend the extra money on amplifiers, tuners and speakers that never get used when all of this is already sitting along side the monitor. By this, I mean, why am I restricted to a 20 watt built-in cheesy amplifier, some lousy expensive speakers and a tuner that cannot tune in cable or satellite channels. The satellite/cable company provides the required tuner with a DVI output, and most people’s sound systems are already next to the TV.
Though many articles praise these monitor only TVs and their outstanding quality, they head off on a tangent when they venture to suggest that they are less for not having a tuner, amp and speakers. Yes, I know, some of these monitors do come with a useless amp, probably for portable uses at trade shows and such. But, how many times have I seen these monitors with powered PC speaker sitting on either side of them.
I wanted these manufacturers to produce JUST A MONITOR ALONE. Leave the all-in-one TVs to the cheap Wal-Mart stuff. I’ll bet if they made the tuner-amp an optional attachable box, I wonder how many of these options would ever get sold.
Well, I was in for an eye opener. In the "old days" when new technology was released, the hardware was produced in component form, meaning each piece was sold separately. it was later when manufacturers would combine them into single units.
The issue here is different. We are dealing with the Copy protection and owned digital data. Referring back to computer monitors not display HD video, the industry is dealing with not one but two issues. First is the HD disks and the second being the cable/satellite providers. So, it often becomes necessary to have a tuner built into the monitor that will accept the Cable Card. Note. these current industrial monitors are not HDCP compliant.
As I said before, in the late 70s and early 80s, people started to invest in home VCRs. There were other open reel and cartridge machines out there but they were rather clunky, hard to use, or expensive. It was when the manufactures started to produce VCRs or Video Cassette Recorders that people began to take an interest in them. By the late 80s more than half the TV watching households had a VCR.
In the early 90s VHS won-out with the introduction of Super VHS. This is not to say everyone went and bought an S-VHS VCR, it was just that they felt they could buy a regular VHS format machine and later upgrade to the Super VHS format without loosing their movies, and priceless memories. So in the mind 90s, the proprietary Sony Beta format lost out and Sony stopped making a home Beta VCR.
Today, even though the ubiquitous Digital Video Disk or DVD ROM (Read Only Memory/Media) has become very popular, people still use the standard VHS VCR to record their TV shows. The cost of a digital recorder is still too expensive. However, people are starting to rent from their television feed providers (cable or satellite) a DVR or digital video recorder built in the proprietary tuner box. One problem thogh. There is no way of saving these programs on permanent media. An example of this type of media is a DVD WORM or write once read many times, AKA DVD-R (record once) or a DVD-RW write & rewrite several times.
As I have said before, most people have had digital high definition video capabilities on their computers since 1993. Today, a lot of people do watch movies on their computers. Many home theater systems use a computer as the backbone of the video-audio system.
But, the television industry is very leery of letting the public save in a transferable form what they watch. In fact, many past TV shows are now being re-released and sold on DVDs.
In the past, the poor quality VHS format was the standard. Today with digital computer technology, the digital TV card mounted into a computer is seen as a major threat to the broadcast industry. The average person can archive and send TV shows over the internet free of charge...with no degradation of picture quality.
In an agreement with the entertainment industry, the cable and satellite television providers are now encoding or encrypting their feeds such that it takes a special decoder for the customer to view the digital information. These companies also offer DVRs. With these boxes, there is no way for the subscriber to capture the pure digital feed or accessing and copying the saved video data files, which themselves are encrypted.
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High Definition Digital Tuners and High Definition
Digital Video Recorder boxes provided by the cable and satellite
companies are not equipped with any raw digital outputs.
The only high definition output available is the rectangular
DVI port that plugs into the back of a DVI capable television.
Even this port is an HDCP or Digital Visual Interface with
High Density Copy Protection. Though many of these LINUX
based boxes are equated with Ethernet, Firewire, and USB
ports, these connections do not allow the user to access
the pure digital video data. |
The following is a response to my inquire as to...what I have been talking about here.
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From:
Customer Service[customerservice@cable.com] Thank you for writing Cable Company Customer Service, We understand that accessibility to HDTV content is already a point of interest to our subscribers, and will only grow as digital broadcasts become more popular. To this end, we are constantly working with our hardware vendors for further upgrades in functionality and equipment, including the possibility of allowing external storage solutions for our DVR, so that we may provide a better entertainment experience. A few points that you may be interested in would be that any TV set, or computer tuner card, with a QAM tuner built in is able to access the majority of our unencrypted digital broadcast feeds. While researching the subject for a specific solution to having a HDTV Home Theater PC setup, we found that CableCard compatible solutions from PC manufacturers should be forthcoming within the next year. As far as not being able to connect a Digital Converter to a specific display, the Digital Converters require that any display connected through DVI or HDMI be HDCP (high definition copy protection) compliant. Component video connections would have no such HDCP check, but would also only be an analogue signal. If the display is HDCP compliant, but you still cannot receive a picture, you may want to turn on the display first, then turn on the Digital Converter. Our DVR service automatically erases a program based on how much recording space is left, and how long ago the program was recorded, not through any signals sent from our offices. Using options through the DVR list, you can choose to keep a program longer by moving it up the list, or until manually deleted.
If we can
ever be of further assistance, please do not hesitate to
contact us either by e-mail at
customerservice@cable.com
or by telephone -- 24 hours a day, 7 days a week -- at the
phone numbers listed below. Please be sure to visit our Web site at www.cable.com for information updates, channel lineups, program listings, and more!
Thank you
again for writing, |
NOTE. Only the local broadcast channels are unencrypted.
But, you say, there is still “Free” local digital TV broadcasts. Well, I feel that this may be short lived. Currently, there are only about 10 OTA digital channels in most major metropolitan areas. And even these are broadcasting poor quality programs. Also, when only about 5% of viewers in a metro area used the analog OTA, then it becomes a significant loss for a television station to power a 100,000 watt transmitter at an average of 150 to $300,000 for energy, maintenance, tower, insurance, and personnel costs per year. I think that it is a matter of time before the government relieves these local stations of the requirement of having to power these expensive transmitters to produce the difficult to receive OTA digital broadcasts, just for a tiny portion of the viewing audience? It takes very little money to send a local television station's feed to a cable/satellite provider though a T1 via the Internet.
This all gets down to the profitability of television and movie producers. The object of any profit center is to produce a product at a maximum price at a minimum of cost. But with competition and an ever demanding public wanting even more expensive and glitzy entertainment, this profit margin grows smaller. Also with the network monopolies fading into hundreds of TV channels, the industry is seeking to find new ways of generating revenue, hence a profit for its shareholders. This means the tightening of the availability of broadcast material. This means more control over television viewing. One of these controls is the commercials that finance most of television broadcasting.
For example, if the technology is available to easily and instantly bleep commercials, then the advertiser will not be able to get the exposure for their produces they need and will turn elsewhere for their advertisement, hence they will not fund television and...there would be no TV, at least commercial TV. There would just be a very high cost for limited television.
The products now being advertised on TV would still be advertised in a different media such as magazines and the internet. The product producer’s advertisement costs would still be the same, so products would still cost the same.
Television, however, would have to fine a different revenue source, and that would be the subscriber. The billions now being spent by the advertisers to bring the programming to the public would become the viewer’s responsibility. This cost would be staggering, about $499.00 per month for what we now have for $49.95 per month. This is for what is considered commercial broadcasting and does not include premium channels such as commercial free special sporting events and movies.
Note. This is an obscurity and I doubt that this would really happen.
The media system I envisioned and tried to built was one that would allow me to tune to any channel the TV feed provider legally provided me, the subscriber. I wanted to build it on a PC computer based platform around an HDTV tuner card along with a hi-definition monitor and a large hard drive.
This system would also allow me to program a small timer that, at a press of the remote, would shoot the program forward in increments of 15, 30, 60, and 90 seconds. At the touch of a button, the system could also go to the next dead spot. Finally it would learn on its own how to bleep commercials.
Next, this system would be connected to my in-house computer network where I could view on any computer a library of TV shows that I saved either by scheduled time, or as I watched then and I decided to keep what I watched.
Finally, I could archive anything on the system on an inexpensive storage media for viewing at a later date, possibly years later. How often have I missed or only caught part of a TV show that I never saw again.
TV would work for me. I could watch what I wanted when I wanted and I could save stuff that is never seen again. And yes, I could cut out all of those debasing demeaning commercials.
So, I did venture forward into the computer realm of operating systems drivers and TV software to build this machine.
As it is now for digital cable and satellite, I sincerely hope that it will not become illegal to have such a system on OTA broadcasts. Like the phone company of the 1950s and 60s, and television in Great Brittan, US TV producers would like television to become more regulated and protected...always for the sake of the viewer.
If all OTA does stop, then so does what little TV viewing I do, do.
To quote an old friend, "I hate TV." I have always detested what American television has stood for. I have felt and I am willing to pose the corollary, "If TV is a reflection of American society and its values, then,...please, God help us." I mean, where did the term Boob-Tube come from. My dad called the thing, "The Lobotomy Box."
Sooooo, I choose not to watch it...most of the time. Never-the-less, the commentary under "I hate TV" kind of describes my feelings as well.
Why is television so bad. I have a theory on that. I believe it has to do with the limitation on bandwidth and control over TV.
There are many lies propagated in the guise of betterment of all, when in reality these deceptions are for the benefit of a few. Case in point is the belief that protectionism will allow for greater technological development. The reality is, history constantly and repeatedly says otherwise.
Example: Unregulated, the Internet was allowed to develop to the point that it has become one of the greatest inventions of human kind. If it were controlled as was the telephone system, like the monopoly called The Bell System, the Internet would have taken 100 years to get where Ma Bell is...well where it was before it got broken up.
Like the phone company, the same could be easily said for television.
Heavily regulated, by modern standards television is still antiquated. Also, within the last 15 years and under the watchful eyes of these regulators, TV has become immoral as well as degrading. Most educators and scalars agree that TV has continued to be an arcane lie that cripples us with its mindless programming, similar to a narcotic. Where did the term "couch potato" come from? TV has also ordained itself a god and tells most how to live while debilitating their minds as well as their bodies.
Because of the regulated monopolistic practices of a few and the deliberate limitation of access for smaller interests being able to broadcasting programming, TV producers being wealthy beyond belief, control what we see and, as a consequence, TV is still like the phone company of yesteryear, bloated and archaic.
The day television is deregulated, is the day TV starts to evolve into something similar to the Internet.
By the way, my TV PC is connected to the Internet. This is where I can download the armature's art and have been able to watch some of the most interesting television.
But now there are pending lawsuits against websites such as the Internet Archive. Being initiated by distant relatives of dead and long forgotten producers who let their stuff go to public domain, unrelated big producers are financing these suites, as they continue to protect their empires.
Yes, there are alternatives to television such as the Internet and free view unencrypted monthly rentals of movies...tens of thousands of them...for only $9.95 a month...far cheaper than 1000 channels of mostly advertisements. One could never see all of the "good" movies in a life time. After all, there are many other things to do besides watch TV...for 4 to 7 hours a day, says government statistics.
I am hoping that the multi-faceted digital age will win out and TV will forced to become free as it has never been before. Then we will see a significant improvement in television technology as well as its content, as we did during the brief time when satellite and cable television was in its infancy and less hindered by regulation and a few corporations. There is a lot of highly moral, intellectual, and fantastic TV that we will never see because it is silenced by the few mega corporations with the help of the FCC.
Simply put, regulation does not improve, rather it stifles.
We are the freest richest nation on earth. Yet our television technology and content is among the poorest. Even third world nations have better TV than we do. WHY? The answer is so stupidly simple. TV is like the phone company was. Only a hand full of owners control all of television. The idea of an amateur or fledging TV producer producing a TV show and getting it aired is just as difficult as it was in the 70s when the average town had only 4 channels. Mind you, we had room for 83 channels, but for some strange reason TV stations were not popping up all over the place. Why?
The answer: the day Ma Bell died, was the day we realized an unprecedented growth in communication technologies, now at pennies on the dollar. It costs far less to make a long distance call in 2005 ($0.02/min) than it did in 1975 ($0.06/min). It's practically free now. But it wouldn't have been possible if we did not deregulate...or rather kill the giant.
Now for the sake of our TV watching children, we must do the same for television...
The more the monopolies want to control, the more we will be stifled and the more we will have to pay. Two examples:
Today we are not use to having anyone much less
Microsoft control and regulate our personal computers. With Windows Vista,
they will restrict what we can do by imposing various internal copy protection
schemes. Any tampering with the software can be construed as a
breach of the license agreement, hence is illegal.
With the new copy protection provisions of the
law, software that we install or equipment we buy can include
all of the functionality built in, yet some of these functions can be
turned off or disabled because we did not purchase this feature or it requires us
to pay each time we use said features.
Examples include Verizon mobile camera phones.
These phones may be able to take pictures and play music, but the only
way one can get the pictures off the phone or music on the phone is
to use the pay per picture/song transfer of images or tunes through
the Verizon network via the Internet to and from the user's PC.
The functionality of transferring images and sounds directly from the
phone to the PC and vise versa has been disabled.
Any tampering or hacking with the phone to enable these features can
be construed as a breach of contract, hence is illegal.
Now that digital TV is here, a greater measure of government control will unfortunately become a reality.
Currently, everything we have including DVDs is copy protection free, meaning, we can see everything, play it at any time, copy it to our portable devices, or lend it to our friends. Nothing stops us from watching and rewatching a recorded TV show, a movie, or listen to music. After we purchase it, It’s all free and clear. We can even record a TV show and watch it many years later. But all that is changing.
The high definition content will be copy protected and highly regulated.
Like current satellite systems found in many homes, every TV will require its own directly connected playback equipment. For equipment manufacturers to comply with these new laws, the sophistication and complication of equipment will grow exponentially.
For the videophile, it will no longer be easy to built a central distribution media based systems in the home. The enthusiast is barred from building equipment to enhance their viewing and listening experience or to make it convenient to distribute around their home this digital information. The idea of a central home video system will be left to very high end homes that can afford the sophisticated data transfer and computerized communication decryption equipment. What ever that will be...
Why do you suppose there are yet to be HD digital video cables at your local Radio Shack, or HDTV modulators to allow you to send HDTV digital video contempt to other HD ready TVs your the house? The answer is, this new digital technology is on hold as the congress hammers out the new laws. Compliance to the law will be very expensive.
As for the average person, if you purchase a TV and you defeat the HDCP functionality, you can be fined and or imprisoned for copy protection infringement.
Basically, like the phone company did the 70s when they first started to sell phones to customers, in essence you own the box, and the ubiquitous ‘they’ own the insides. Under the provision of the Intellectual Property Rights Act law, you have no legal rights to access and modify the insides of the equipment you own. Also, ALL REPAIRS MUST BE PERFORMED BY AN AUTHORIZED REPAIR CENTER.
The liabilities associated with having copy protected equipment, media, and software in your home grows.
Up to and including Windows XP, one could safely install and use bootleg software, which many people do. With the introduction of Windows Vista (Longhorn) all of this will become a thing of the past. Every piece of software that one installs on their computer must be registered with a special unique copy protection key, as is the case now. The only difference is, with the help of Windows Vista, the software will detect any infringements and will either disable the PC or possibly report the violation via the Internet connection.
For a PC, it would be replacing Microsoft's costly software with a freeware OS such as the many flavors of LINUX, Darwin (similar to Apple’s Mac OS 10), another Intel version of Open BSD Unix, SUN Microsystems Solaris, or risk staying with a current version of Windows. One could also purchase a new PC such as Apple’s Mac G4 & G5, Sun’s Sparc system, or other non-Windows based hardware. Note, the boundaries between Windows and these other systems are growing.
As for high definition digital TV, there are currently no definitive answers for this. The law is still being negotiated. There are very strong pressures on law makers to institute more of these restrictive limitations.
Mind you, I am not an advocate of piracy. Contrarily, I strongly believe in paying for the honest hard work that others do. I do not believe in illegally copying or steeling music, video, text, images, or software. But at the same time, I disdain Big Brother looking over my shoulder verifying everything I do or having stuff in my home I'm liable for if I tough it. I want the technology to work for me and serve me on my terms, not the whim of a monopolistic profit center protected by the severity of the law.
I understand there are a few who do break the law, but I believe most people are honest. The problem I have is that society seems eager to punish all of us in a dysfunctional and futile effort to stop the pirates. In the end like the gun control laws, the criminals will still have their guns and the pirates will still figure out how to defeat copy protection.
As for me. You-know, this is all a moot point. I remember many times when various government agencies, the recording industry, and manufacturers tried to implement copy protection. In the end, it never worked out. The public rejected these notions and everyone in the industry could not get their act together.
Remember when cable TV subscriber had to have a cable box? There was the quirky VHS VCR situation with white bars when one would record a movie from a premium cable channel. Then there was talk about copy protection of CDs. They were going to leave a bit out at certain points in the music or...whatever. Then there was DVD copy protection that is supposed to be in current DVD technology. I'll bet over a third the players no longer support these protections. These players are called Code Free Players and Region Free Players.
I hope the same happens with the HD industry. I hope people reading this will understand and reject these overly protective notions. I hope the industry once again come to their senses and does away with these ideas.
But in the mean time, I guess I have decided not to buy, borrow or rent any copy protected high-definition equipment. So, if I do this, then I can't buy, borrow or rent any copy protected media. Also, I doubt that I would buy or illegally install on my personal PC WV (Windows Vista) or, for that matter, any other restrictive software.
If I cannot legally buy it or rent it at a reasonable cost, get it for free, or borrow it, and use it without control, restrictions and fear of reprisals, then I will not have it, see it, hear it, or use it.
I mean after all, It's the principle of the thing.
I look forward to the free digital revolution...
SteveS July 16, 2005 (rev 01/20/06)