1080P: TIME FOR A REALITY CHECK!

[erdega79]

http://www.hdtvexpert.com/pages/reality.htm

This is the type of article that really explains the reality of hdtv. Basically it will cost a lot to implement true hdtv and the main problems are circuits and bandwidth and outdated formats.


I see bandwidt as the easiest hurdle here although it's not as easy as it seems. It will be long time before it can be brodcast but I believe the discs or any future local sources for hdtv will handle it easier. The other two hurdles are political and economical. Formats will take a whole lot of wrangling to update whereas updating display circuitry like the long time coming. I am no expert on this at all but it seems if it was doable at all it would be done by now and it probably requires a whole new design and new sets of costs.

Thinking about buying a new 1080p rear-projection TV, front projector, or LCD TV? You might want to put your credit card back in your wallet after you read this.

It’s obvious that the buzzword in consumer TV technology this year is “1080p”. Several manufacturers are showing and shipping 1080p DLP and LCoS rear-projection TVs. We’ve seen RPTVs and front projectors with 1920x1080 polysilicon LCD panels at CESA, NAB, and InfoComm. And the trickle of large LCD TVs and monitors with 1920x1080 resolution is turning into a flood.

To get your attention, marketers are referring to 1080p as “full spec” HD or “true” HD, a phrase also used by more than one HD veteran in the broadcast industry. We’re hearing about “1080p content” coming out of Hollywood, from broadcasters, from cable systems, and from direct broadcast satellite services.

The budding format war between Blu-ray and HD DVD for the next generation of high definition DVD players promises the same thing – 1080p content at high bit rates, finally realizing the full potential of HDTV.

STOP!

Enough of this nonsense. It’s time to set the record straight, to clear up the air about what 1080p is and isn’t.

First off, there is no 1080p HDTV transmission format. There is a 1080p/24 production format in wide use for prime time TV shows and some feature films. But these programs must be converted to 1080i/30 (that’s interlaced, not progressive scan) before airing on any terrestrial, satellite, or cable TV network.

What’s that, you say? Those 1080p/24 could be broadcast as a digital signal? That’s true, except that none of the consumer HDTV sets out there would support the non-standard horizontal scan rate required. And you sure wouldn’t want to watch 24Hz video for any length of time; the flicker would drive you crazy after a few seconds.

No, you’d need to have your TV refresh images at either a 2x (48Hz) or 3x (72Hz) frame rate, neither of which is supported by most HDTVs. If the HDTV has a computer (PC) input, that might work. But if you are receiving the signals off-air or using a DVI HDCP or HDMI connection, you’ll be outta luck.

What about live HDTV? That is captured, edited, and broadcast as 1080i/30. No exceptions. At present, there are no off-the-shelf broadcast cameras that can handle 1080p/60, a true progressive format with fast picture refresh rates. It’s just too much digital data to handle and requires way too much bandwidth or severe MPEG compression. (Consider that uncompressed 1920x1080i requires about 1.3 gigabits per second to move around. 1080p/60 would double that data rate.)

How about Blu-ray and HD-DVD? If either format is used to store and play back live HD content, it will have to be 1920x1080i (interlaced again) to be compatible with the bulk of consumer TVs. And any progressive-scan content will also have to be interlaced for viewing on the majority of HDTV sets.

Here’s why. To cut manufacturing costs, most HDTV sets run their horizontal scan at a constant 33.8 kHz, which is what’s needed for 1080i (or 540p). 1080p scans pictures twice as fast at 67.6 kHz. But most of today’s HDTVs don’t even support external 720p signal sources, which requires a 44.9 kHz higher scan rate.

In the consumer TV business today, it’s all about cutting prices and moving as many sets as possible through big distribution channels. So, I ask you: Why would HDTV manufacturers want to add to the price of their sets by supporting 1080p/60, a format that no HDTV network uses?

Here’s something else to think about. The leading manufacturer of LCD TVs does not support the playback of 1080p content on its own 1920x1080 products, whether the signal is in the YPbPr component or RGB format. Only the industrial monitor version of this same LCD HDTV can accept a 1920x1080p RGB signal.

Now, don’t blame HDTV manufacturers for this oversight. They are only supporting the 1080 format in actual use, 1920x1080i, a legacy digital format that has its roots in the older Japanese MUSE analog HDTV format of the 1980s. That’s one big reason that 1080i has remained as a production and transmission format.

It gets worse. All kinds of compromises are made in the acquisition, production, and transmission of 1080i content, from cameras with less than full resolution in their sensors and reduced sampling of luminance and chrominance to excessive MPEG compression of the signal as it travels from antenna, dish, or cable to your TV.

But that’s not all. To show a 1080i signal, many consumer HDTVs do the conversion from interlaced to progressive scan using an economical, “quickie” approach that throws away half the vertical resolution in the 1080i image. The resulting 540p image is fine for CRT HDTV sets, which can’t show all that much detail to begin with. And 540p is not too difficult to scale up to 720p.

But a 540p signal played back on a 1080p display doesn’t cut the mustard. You will quickly see the loss in resolution, not to mention motion and interline picture artifacts. Add to that other garbage such as mosquito noise and macroblocking, and you’ve got a pretty sorry-looking signal on your new big screen 1080p TV.

Oops! Almost forgot, that same 1080p TV may not have full horizontal pixel resolution if it uses 1080p DLP technology. The digital micromirror devices used in these TVs have 960x1080 native resolution, using a technique known as “wobbulation” to refresh two sets of 960 horizontal pixels at high speed, providing the 1920x1080 image. It’s a “cost thing” again. (Let’s hope these sets don’t employ the 540p conversion trick as well!

To summarize: There are no fast refresh (30Hz or 60Hz) 1080p production or transmission formats in use, nor are there any looming in the near future – even on the new HD-DVD and Blu-ray formats. The bandwidth is barely there for 1080i channels, and it’s probably just as well, because most TVs wouldn’t support 1080p/60 anyway – they’d just convert those signals to 1080i or 540p before you saw them.

The 1280x720 progressive-scan HDTV format, which can be captured at full resolution using existing broadcast cameras and survives MPEG-2 compression better than 1080i, doesn’t make it to most HDTV screens without first being altered to 1080i or 540p in a set-top box or in the HDTV set itself. So what chance would a 1080p signal have?

Still think you’ve just gotta have that new 1080p RPTV? Wait until you see what standard definition analog TV and digital cable look like on it…

[phloyd]

Nice article.

It is however written by someone who is not much of a fact checker.

ATSC does include 1080p at 24 fps and 30 fps.

Also, flags can be used to turn 24p into 29.97i just like with DVD's.

So, backwards compatibility can be maintained with a 24p authored disc.

As to whether the screens will support 24 fps 1080p - that is up to the maker of the screen. Buyer beware...

Cheers!
DAve.

[erdega79]

Originally Posted by phloyd

Nice article.

It is however written by someone who is not much of a fact checker.

ATSC does include 1080p at 24 fps and 30 fps.

Also, flags can be used to turn 24p into 29.97i just like with DVD's.

So, backwards compatibility can be maintained with a 24p authored disc.

As to whether the screens will support 24 fps 1080p - that is up to the maker of the screen. Buyer beware...

Cheers!
DAve.

I think he is saying that although 1080p/24 exists it has to be converted to 1080i before it can be broadcast. 1080p/24 could be broadcast but none of the tv sets accept it and apparently 24 frames is too slow and introduces flicker. I think he is gunning for 1080P/60 which sounds good to me but it's not a standard yet.

He also mentions circuitry and cost of that which is too big now especially since there are no sources like that which would require for true hdtv.

[phloyd]

Since 24p and 30p are part of the ATSC spec, any device claiming to be compatible should handle this as input.

In that sense, there should not be a chicken and egg kind of thing with Blu disc not wanting to do 24p since 'there are no displays'... all ATSC capable displays should do something with 24p or 30p.

Sadly most will not do what you might hope - most will convert/scale to 1080i or 720p

1080p 60 is a different ball game - PS3 might do it for games and PC's can do it - I can't imagine seeing filmed content that way unless we get extra bandwidth on Sat or Cable.

Of course, Blu discs could have 1080p 60fps content on them - but the player might have to be capable of downconverting. I doubt that there are any plans for that...

Cheers!

[erdega79]

Originally Posted by phloyd

Since 24p and 30p are part of the ATSC spec, any device claiming to be compatible should handle this as input.

Yes, but when you read the article , it says that for 1080p inputs on tv sets , it must have higher and more expensive circuitry and since there are no current 1080p sources manufacturers choose to skip it and skim the costs. That's why we must have 1080p sources as soon as possible!

Originally Posted by phloyd

In that sense, there should not be a chicken and egg kind of thing with Blu disc not wanting to do 24p since 'there are no displays'... all ATSC capable displays should do something with 24p or 30p.

Fortunatelly BD can and should offer 1080p sources 24/30.

Originally Posted by phloyd

Sadly most will not do what you might hope - most will convert/scale to 1080i or 720p

That's what they are doing today. What I hope and think will happen is that once BD arrive next year, we will see 1080p inputs too for true 1080p

Originally Posted by phloyd

1080p 60 is a different ball game - PS3 might do it for games and PC's can do it - I can't imagine seeing filmed content that way unless we get extra bandwidth on Sat or Cable.

1080p/60 is not a standard now but I certainly hope it's in the works for future especially for games. Most displays will have no problem with it, lcd tv's for example.

[phloyd]

1080p/60 is a standard in the sense that there is a standard way to clock it out...

It is just not part of the transmission standard.

Don't get me wrong, I am all for 1080p and look forward to that at 24, 30 or 60 as it becomes available.

Cheers!

[thunderhawk]

And you sure wouldn’t want to watch 24Hz video for any length of time; the flicker would drive you crazy after a few seconds.

You can have an input of an 24 Hz signal, edit it in the memory and have an 100 Hz output like some of the Panasonic display.
Solved

Don't get me wrong, I am all for 1080p and look forward to that at 24, 30 or 60 as it becomes available

I don't know how it is with the bandwith in North-America, but here in Europe, we will have (they claim they will) when HDTV launches, ... ? How much do you need for HDTV broadcasting? ops: :? :|

[john_1958]

i scan DVDO is a User defined output video resolution from 480p up to 1080p
your DVD player at 480p, or your Set-top-box at 720p or 1080i, the iScan™ HD+ will scale the output to perfectly match the optimum resolution of your display - 720p, 1080i, or any user-defined resolution up to 1080p i can see this product to help boost 1080p tvs to be able to take regular broadcast to extreme HD because right now 1080p tvs just don't cut it
But would perfer 1080p broadcast

[Rob]

I have yet to come accross a tv that accepts 1080p 50/60hz. Most 1920 by 1080 sets only accept 1080i 60/60.

[Gorkab]

Originally Posted by thunderhawk

I don't know how it is with the bandwith in North-America, but here in Europe, we will have (they claim they will) when HDTV launches, ... ? How much do you need for HDTV broadcasting? ops: :? :|

We have a channel ! ONLY ONE !!!! Euro 1080...

[thunderhawk]

Originally Posted by Gorkab

We have a channel ! ONLY ONE !!!! Euro 1080...

Yeah... And I don't like sports! :lol:

[Gorkab]

Originally Posted by thunderhawk

Yeah... And I don't like sports! :lol:

And it's too expensive for only one channel !!! I'm now waiting for the MPEG-4 TNT HDTV

[thunderhawk]

You're waiting for the what?

I never heard of it... :? Could you supply me with some information? :roll:
:mrgreen: Thanks on Advance dude!!

[Gorkab]

So, the TNT (Terrestrial Numerical Television) will broadcast MPEG-4 soon and so it will use less bitrate than the MPEG-2 currently used for free channels. So, we will have HDTV AND AC3 !!!

[mk_kenshin]

I still want 1080p I dont care what my SD content looks like on a 1080p tv I want full quality not some half job.

[Knight-Errant]

Correct me if I'm wrong but wouldn't 1080p/30
result in similar playback problems for films as PAL (play speed and thus pitch change)?

Surely if films are made at 24 fps they ought to be displayed at 24 fps? Anyone?

If I'm totally wrong, please correct me :?

[thunderhawk]

I think the players will be technically the same when reading the discs with the laser.
Its the processing unit and the software used that will be different and result in another output.
And maybe your TV set will raise the fps to 100. Which will result in 1080p24 played at 1080p100, perfectly possible and better for your eyes
Please correct me if I'm wrong too ops: :lol:

[Knight-Errant]

Originally Posted by thunderhawk

I think the players will be technically the same when reading the discs with the laser.
Its the processing unit and the software used that will be different and result in another output.
And maybe your TV set will raise the fps to 100. Which will result in 1080p24 played at 1080p100, perfectly possible and better for your eyes
Please correct me if I'm wrong too ops: :lol:

:lol:

Inquiring minds want to know heh

I'll be happy as long as my films play at the right speed tbh

[HT Fan]

This article is proof positive that a little bit of knowledge can be a dangerous thing.

So many false assumptions and inaccurate conclusions based on a person knowing a couple of things and trying to figure the rest out for himself/herself.

Plain and simple. All BD pre-packaged movie software should be 1080p. The then current player should be able to convert it to resolutions and frame rates then currently supported by television manufacturers. When more TVs support 1080p, then more players should be able to output 1080p. But if I buy a disc now, I better be able to watch that same disc several years later at full 1080p resolution when more TVs and BD players can accept and display this resolution.

[Rob]

I would assume that movies would be 1080p24 as they are currently 24fps encoded on dvd. In the Uk this would equate to 1080p50 with each frame being shown twice, and an extra 2fps. In the USA/Japan you'd have the normal 2:3 pulldown where 24 frames are converted into 60fps.