HDTV formats

[jack19]

I have come to know that there are two formats on HDTV — 720p and 1080i. Is there any difference in these formats and can my television receive both these formats....?

Any suggestions will be Appreciated..

[litzdog911]

Tough to answer without knowing what TV you have.

Here's a nice overview of HDTV that should answer your question ....
http://tv.about.com/od/hdtv/a/whatisHDTV.htm

[TyroneShoes]

Modern HDTV sets (2003+) can typically receive and display all ATSC formats. Actually, there are 36 ATSC DT formats if you count all combinations of resolution, frame rate, and aspect ratio. The two most typical are 1080i/29.97 and 720p/59.94 which is what most stations broadcast HD in, and formats with resolutions below 720 are not technically considered "HD". There are even more permutations of HD beyond OTA ATSC, one being the 1280x1080 format used by DTV.

[JimSpence]

Rant Mode On

Why the heck did the FCC allow so many HD formats? They should have selected one of them and mandated that. Then we wouldn't have so many discussions about what is HD. I think HDTV manufacturing costs might be a little lower if there was only one format.

Rant Mode Off

BTW, My Mitsubishi WS48311 can only handle the 1080i HD resolution.

[bdlucas]

Why the heck did the FCC allow so many HD formats?
Political compromise. Consensus couldn't be reached on a single format.

[dalecripps]

There would be no HDTV had one format been demanded from the start. In the end the multiple formats did not cost the industry or end users anything but the price of confusion. Early interest in multicasting and concerns for native display technology led to the many formats. The cost of the chip was amortized across a larger market than had there been only one HDTV standard (which would have had to be 1080 based). As a result the total cost of the decoding chip for all formats is made insignificant AND the many formats allowed for cheaper displays, such as the native 720p. Now, of course, we enter into the era of 1080p displays (1080p 24 fps is part of the ATSC standard) which is providing stunning results AND with no new costly decoding chip needed to inhibit public acceptance. From my view the multiple format decision was not an evil, as often portrayed, since it gave many seperate interests an incentive to act in the marketplace where had there been one format (the computer groups wanted 480p as the end all and lobbied around the world for that. Imagine getting stuck at 480p!) the market would have been less stimulated by all of the trial, diversity, and price points.

[TyroneShoes]

dupe deleted

[TyroneShoes]

Rant Mode On

Why the heck did the FCC allow so many HD formats? They should have selected one of them and mandated that. Then we wouldn't have so many discussions about what is HD. I think HDTV manufacturing costs might be a little lower if there was only one format...
The ATSC did an excelent job, IMHO. I vigorously disagree on all points...that they should have selected one format, that "so many discussions" about HD have any kind of downside at all, and that costs would be lower.

The goals were flexibility, global interoperability, low cost, and a smooth transition from NTSC, while providing a framework where they could coexist during the overlap period. All of those goals were met, and while we still have a couple more phases to go (analog shutoff for OTA, CATV conversion to all digital) the transition has been a resounding success, with few if any glitches.

Having many formats available is key to all of these goals including low cost. The cost of meeting the other goals is added complexity and an insignificant increase in cost, particularly for the consumer, but costs would not be lower if the format were restricted as you suggest.

Multi-scan monitor technology is cheap and ubiquitous, and the end-user transparency has not been impacted adversely by the complexity. 99% of the complexity and the extra cost, which is minimal, falls on the broadcasters and vendors, and they are certainly up to the task.

It can be argued that if we were given a system with lower complexity and lower hardware cost, that the end cost would actually be much higher due to the problems that would cause for broadcasters and HD set makers alike, and that we would either be restricted in what global sources might be compatible or that the quality of many of them would be compromised due to poor interoperability.

Certainly there would be no computer interoperability without multiple formats, and DTV would not be able to provide the few HD channels they do if they were restricted to 1920x1080 with the same level of quality that they do. The transition would take much longer, and be significantly more painful for all. Multiple formats allows different approaches for different tasks, which is a blessing. Practically speaking, one size can't fit all.

The founding fathers of DT took a difficult task and hit a grand slam, IMHO. If they had chosen one format, it would have been 1080p/24, because it is compatible with every other HD format available worldwide, and all of them can be extracted from it without degradation. But in 1997 there were no 1080p monitors, so displays would not have been compatible and PQ would have been impacted.

Also, the data rate for a 6 MHz channel tops out at 20 mb/s, so there would have been no practical way to deliver it in that format since it implies a higher data rate within the limits of practical image compression technology.

Bottom line, with a single format we would not be even close to where we are today in terms of the transition, PQ, cost, and content availability. Thank your lucky stars the ATSC committee knew what they were doing, or we'd be watching NTSC for at least another 10 years, and there would be no video on phones, ipods or computers. YouTube and the iTunes video store would not exist. Without encouragement from the ATSC decisions and the environment it created, MP3s would probably not even be available to the masses.

[JimSpence]

And why did you post almost the same reply twice?:)

Anyway, I'm glad that the FCC decided on one color broadcasting method way back when. :)

So why couldn't they have dictated 1080 as the standard and let the "i" and "p" part get worked out later?

[TyroneShoes]

Don't pretend to not understand that duplicate posts can be posted when internet connections become momentarily interrupted. It happens to everyone, including you, and it was immediately corrected, in my case. It's a fact of life, and you know it, so trying to use that to undermine my disagreement with your reasoning comes off as desperate and childish, which is somewhat beneath you.

I'm happy you considered NTSC to be a great choice for color broadcasting. But you are certainly in the minority. It had its very vocal critics in 1953, and has hamstrung the industry ever since, compromising PQ and greatly complicating all aspects of television broadcasting. No one in the industry is a fan, and all of us are glad to say "good riddance" to such a poor design.

Technology moved at a snail's pace in 1953, implying that NTSC decisions would be OK even if not far-seeing. That turned out to completely wrong. Neither the NTSC committee nor the ATSC committee had a crystal ball, but ATSC was exceptionally visionary in an enviroment where tech change happens every second, while it is historically accepted that the NTSC couldn't see beyond the end of ther noses. The results prove that.

Your posts imply that you probably think and reason much more like the members of the NTSC committee than the members of the ATSC committee, but that's OK. We all still love you.

[Ein]

Anyway, I'm glad that the FCC decided on one color broadcasting method way back when. :)



They did not have any choice. RCA had the only system that can broadcast color TV signal that a B/W TV can also receive (not in color).