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Another 1080p/1080i/720p discussion, pulled from D11 thread


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110 replies to this topic

#21 OFFLINE   dewey

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Posted 17 June 2008 - 07:57 AM

Just as a curious side point... last night I was thinking about the moon and its effect on the earth (tides, etc.) and wondered just how much does it affect the orbit of a satellite such as D11. Getting online this morning, I did a quick search of this thread and saw a few comments that refer to this, but I didn't find anything that says how much of an effect it is.
Is this something that needs to be routinely corrected every 28 or 14 days, or are DBS allowed to drift because of lunar and other gravitational forces, drag, solar wind(?), and other cumulative errors until such time that a correction has to be made? Perhaps these effects are so small that there are no routine adjustments and they're just done as needed.
Are there actually rules that define how far a satellite may drift before the FCC step in with a warning, or does it never even come close to that - presumably because there would simply be a customer outcry due to poor reception before that would occur?
Hey guys - once again, as with D10, this thread is a fascinating read - many thanks to the people that really take the time explaining this (we all know who they are!).



What does this question have to do with 780p vs. 1080i resolution? Stay on topic! ;)
Seriously, I was hoping for an informed response to this question. thx
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#22 OFFLINE   man_rob

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Posted 17 June 2008 - 08:03 AM

"1080i has more lines and pixels, but 720p is a progressive-scan format that should deliver a smoother image that stays sharper during motion..."

Too bad should doesn't always work out. I've seen ATSC documentation showing 1080i offers a sharper picture during motion than 720p can.

http://www.atsc.org/...ts/tsreport.pdf

________________________________
Anyway, how would Directv integrate this BSS technology into their current plans and hardware?



From the report to which you linked:

The 720P mode showed no artifacts in tests for motion-compensated overload with horizontal, vertical, or diagonal motion up to 0.8 picture heights per second. The 1080I mode showed no artifacts for horizontal motion, but did show increasing quantization noise and blockiness for vertical and diagonal motion.



I believe that the BSS technology would be used for broadband services, perhaps replacing land lines for on demand services?

#23 OFFLINE   gregjones

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Posted 17 June 2008 - 08:24 AM

Start yet another thread for the 720p/1080i diatribe. There are at least 10 lingering out there. Please do not dillute this thread further with a discussion that has been ongoing for years.


Back on topic, I still wonder if the actual (re-)release date for EncoreHD will be a signal for the first use of D11. I don't recall seeing a date more specific than July for this launch. It would be a bit odd for DirecTV not to be the first to carry it, since it is a Malone channel.

#24 OFFLINE   cartrivision

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Posted 17 June 2008 - 12:22 PM

Lots of DTV channels are broadcast in 720P and 720P is considered to be better by many then 1080i especially with motion. A 720P set will display satellite signal as good as a 1080p in my opinion.


Actually, when you display a 1080i signal on a 720p set you only have half the pixels of resolution compared to what you would see on a 1080p set. That might be good enough for you in your opinion, but it's not as good as displaying it on a 1080p set since displaying a 1080i signal on a 720p set yields a significantly lower resolution picture.


I think thats a misleading statement that you "need a 1080p tv or your only seeing half the pixels of resolution" It makes it look like you need a 1080p set but that is wrong.


There is nothing misleading whatsoever about that statement. It is an absolute fact. A 720p set displays half the pixels of resolution that you would see on a 1080i set when watching a 1080i signal.

#25 ONLINE   LameLefty

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Posted 17 June 2008 - 12:39 PM

STOP THE 1080i v. 720p DEBATE. PLEASE TAKE IT TO PMs!!!

Geez, you've already been asked obliquely and then again DIRECTLY by a Moderator! What more do you need? :rolleyes:

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#26 OFFLINE   cartrivision

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Posted 17 June 2008 - 12:40 PM

I wouldn't be too sure about that (remember the original "leaked" photos of the HR21 Pro that clearly showed a 1080P indicating light), the bandwidth required to broadcast 1080/24P is pretty much the same as 1080/60i so I would not be too surprised to see PPV movies broadcast in 1080/24P...just me speculating of course...


A 24fps movie that is broadcast in 1080i/60 format already contains all the information in the 1080i video that would be present in 1080p/24 video, so it's just a matter of deinterlacing it into a 1080p24 signal.... there is no need to broadcast it as 1080p/24, although there might be some bandwidth savings from doing so.

#27 OFFLINE   Dolly

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Posted 17 June 2008 - 02:41 PM

Well while I can't say I understand all this stuff about resolution on a TV. It doesn't sound like I will have to worry about having a worthless TV in the near future. That was my main concern.

#28 OFFLINE   JeffBowser

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Posted 17 June 2008 - 02:56 PM

Hey, I haven't mentioned my cousin's work at Panavision on quad-hi definition cameras in ages. Who cares about 1080 or 720 in any format, when one can have 7680x4320p ? :lol:
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#29 OFFLINE   cekowalski

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Posted 18 June 2008 - 12:53 AM

I don't totally get why this is such a huge debate, other than the fact that it is poorly explained, in general, and poorly understood.

Drop the "i" vs. "p" as it doesn't matter with most modern displays. An interlaced picture is de-interlaced on most modern televisions, before it gets displayed. The difference is that in 1080i, you get a 540 line image 60 times per second (which get combined to become a 1080 line image that displays every 1/30th of a second, on modern displays). At 1080p, you get a 1080 line image the displays every 1/60th of a second. Effectively, you're looking at a 1080 line image on 1080i displays, but at a lower frame rate (30 fps) than 1080p (60 fps). That's the only difference.

So do you want 30 frames per second, or 60 frames per second? If bandwidth is no consideration, everyone would say 60. But if every 2nd frame is a repeat of the previous one, do you really care? Films are 24fps. That can't be upconverted unless you speed the film up. So the vast majoriy of Hollywood films don't look any better in 1080p than they do in 1080i.

Movies are 24fps, so the 1080i format has that covered when upconverted to 1080p. In fact, I think Blu-Ray being 1080p(60) is a marketing thing. How can a 1080 line, 24 fps image, look better when reproduced on a 1080 line 60 fps display, vs. a 1080 line 30 fps display?

Now, do you want more HD channels, or more frames per second on the ones you have?

What about this? (and the debate of 720p vs 1080i repeats)... do you want 1080 lines at 60 fps, or 2160 lines at 30 fps?

I think TVs will get bigger yet again, and the next era will bring higher resolutions, not higher frame rates, for most material.

My main thought here -- don't think of this in terms of your circa 1990 CRT computer monitor. Interlacing looks bad on CRT monitors, not LCD or Plasma panels, or even projection LCD/DLP/LCOS. These displays don't "fade" out and cause flicker. The debate is not "flicker" vs. "not flicker." It's frame rate.

1080i vs 1080p is a 30 fps vs. 60 fps debate. So which is more bang for the buck -- more pixels per frame, or more frames per second?

I think the requirements of 1080p, bandwidth-wise, would give birth to a new, lower frame rate, higher resolution format, and the debate will continue.

#30 OFFLINE   richlife

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Posted 18 June 2008 - 05:44 AM

This opinion is purely subjective, but I completely agree with the statement that 1080 is better than 720 just because it can display twice as much detail.

I have two Sony's using the same LCOS technology with rear projection (I deliberately sought out the last of the rear projection runs for cost effectiveness and picture quality -- good decision). Both TVs look great, but the 50" 1080p is significantly better than the 37" 720p despite the screen size increase (which will display flaws more easily). Sitting at 12 feet, the difference is minimal and shows mainly as slightly less crispness in the 720p. At 2 feet (obviously not a viewing distance) you can see why -- the 1080p is drop dead gorgeous with magnificent 3-D effect. At 2 feet, the 720p has lost it's smooth image and is broken up into pixels, dots, screen door effect, whatever. Even with DirecTV broadcasts, I can usually tell when the image is 1080i vs. 720p. (A crappy broadcast will always be crappy and 1080i doesn't make it better.) My decision? I would buy 1080p for a primary system -- especially if the viewing distance will be relatively short (8-10 feet). Any other set becomes more of a price/performance question with the 1080p as the reference point.

I don't buy the 720p for sporting events (high speed action) at all. I think it's more dependent on the quality and speed of the set. 720p just takes advantage of the fact that many sets just aren't good enough to display the difference.
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A) HR20-700: NR 4aa; HDMI Audio: HDMI, TOSLINK. Res-1080i; Native- On; eSata-No; Remote-RF (2).
B) HR23-700: NR 4aa; Video&Audio HDMI. Res.-720p; Native-On; Network-No; eSata-No; Remote-IR.
C) H23-600: NR 0440; HDMI. Res.-1080p; Native-On; eSata-No; Remote-IR.
TVs: A) Sony 50" Rear Proj KDS50A2000 & VIZIO 22" LCD M220VA; B) Sony 37" Rear Proj KDF37H1000; C) Toshiba 40" LCD 40FT1U

#31 OFFLINE   morgantown

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Posted 18 June 2008 - 11:32 AM

Mods - thank you so much for pulling this discussion from the D11 thread! I hesitated to ask about 1080p and BSS, but could not resist. Sorry it ended up in a thread-jack.

For the record - I still have not completely decided which to get for my newly finished rec. room / bar area. Given that people can sit at the bar and be very close richlife's post has me thinking more about 1089p.

However I'm only looking at a 32" set for the bar part and most people wil be 6' to 30' away which makes me think 720 should be just fine. The "main" TV on the otherhand - I think I'll just wait untill the Fall and get a whopper of a 1080p as it will eventually become the most used TV in the house.

Great discussion and good information. It is always good to get input from folks that are looking at the same DirecTV source as me when comparing TVs.

Thank you to all.
DTV & NFLST since 97 at least, not looked back yet...

#32 OFFLINE   P Smith

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Posted 18 June 2008 - 12:43 PM

A few threads where the aspects discussed intensively:

http://dbstalk.com/s...ad.php?t=126130
http://dbstalk.com/s...ad.php?t=122146
http://dbstalk.com/s...ad.php?t=117146
http://dbstalk.com/s...ad.php?t=110101
http://dbstalk.com/s...ad.php?t=103373
and many more.

[Just used Search for "1080p bandwidth"]

#33 OFFLINE   Steve Robertson

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Posted 18 June 2008 - 12:46 PM

Well I just go by my eyes and after viewing ESPN, ABC, and Fox for a few years now I think 720p sucks.

#34 OFFLINE   BattleZone

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Posted 18 June 2008 - 01:10 PM

A 720P set will display satellite signal as good as a 1080p in my opinion. I install HD tv's and hi-def Dish and HD Direct all the time and many 1080p sets look horrible in my opinion. Cant beat a Panasonic plasma for the price and even the 720 Panasonics look as good as the 1080ps.


I must *strongly* disagree with you here.

There is a large and very noticable difference between the picture quality of TVs with native resolutions of 1366x768 (the most common native resolution below "full-HD", and commonly referred to as a "720p" TV) and those at 1920x1080.

I agree that not all content can show the difference, but there is plenty of programming on DirecTV that does, and even more with Blu-Ray and computer content.

IMO, it is much more important to have a TV with a true 1920x1080 native resolution than to worry so much about progressive vs. interlaced (1080p vs. 1080i). Yes, progressive does look slightly better in higher-motion frames IF there is enough bandwidth to prevent compression artifacts. And, yes, because sat broadcasts have limited bandwidth, they often use 720p instead of 1080i for high-motion content. But 720p content looks as good on a 1080 TV as it does on a 720p TV, but the reverse is not true.

And while 1080p satellite or cable broadcasts are at the very, very least a decade or more away, 1080i has been here for years and is the standard for MOST HD content.

#35 OFFLINE   man_rob

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Posted 18 June 2008 - 01:11 PM

Here's some interesting info.

While 1080i has more scan lines than 720p, they do not translate directly into greater vertical resolution. Interlaced video is usually blurred vertically (filtered) to prevent twitter. Twitter is a flickering of fine horizontal lines in a scene, lines that are so fine that they only occur on a single scan line. Because only half the scan lines are drawn per field, fine horizontal lines may be missing entirely from one of the fields, causing them to flicker. Images are blurred vertically to ensure that no detail is only one scan line in height. Therefore, 1080i material does not deliver 1080 scan lines of vertical resolution. However 1080i provides a 1920-pixel horizontal resolution, greater than 720p's 1280 resolution.

http://en.wikipedia.org/wiki/720p



#36 OFFLINE   P Smith

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Posted 18 June 2008 - 02:06 PM

The future of 1080p broadcast is here - XstreamHD !
And reading old threads will give more facts - http://dbstalk.com/s...ad.php?t=115434

#37 OFFLINE   rudeney

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Posted 18 June 2008 - 03:11 PM

I don't totally get why this is such a huge debate, other than the fact that it is poorly explained, in general, and poorly understood.

Drop the "i" vs. "p" as it doesn't matter with most modern displays. An interlaced picture is de-interlaced on most modern televisions, before it gets displayed. The difference is that in 1080i, you get a 540 line image 60 times per second (which get combined to become a 1080 line image that displays every 1/30th of a second, on modern displays). At 1080p, you get a 1080 line image the displays every 1/60th of a second. Effectively, you're looking at a 1080 line image on 1080i displays, but at a lower frame rate (30 fps) than 1080p (60 fps). That's the only difference.

So do you want 30 frames per second, or 60 frames per second? If bandwidth is no consideration, everyone would say 60. But if every 2nd frame is a repeat of the previous one, do you really care? Films are 24fps. That can't be upconverted unless you speed the film up. So the vast majoriy of Hollywood films don't look any better in 1080p than they do in 1080i.

Movies are 24fps, so the 1080i format has that covered when upconverted to 1080p. In fact, I think Blu-Ray being 1080p(60) is a marketing thing. How can a 1080 line, 24 fps image, look better when reproduced on a 1080 line 60 fps display, vs. a 1080 line 30 fps display?

Now, do you want more HD channels, or more frames per second on the ones you have?

What about this? (and the debate of 720p vs 1080i repeats)... do you want 1080 lines at 60 fps, or 2160 lines at 30 fps?

I think TVs will get bigger yet again, and the next era will bring higher resolutions, not higher frame rates, for most material.

My main thought here -- don't think of this in terms of your circa 1990 CRT computer monitor. Interlacing looks bad on CRT monitors, not LCD or Plasma panels, or even projection LCD/DLP/LCOS. These displays don't "fade" out and cause flicker. The debate is not "flicker" vs. "not flicker." It's frame rate.

1080i vs 1080p is a 30 fps vs. 60 fps debate. So which is more bang for the buck -- more pixels per frame, or more frames per second?

I think the requirements of 1080p, bandwidth-wise, would give birth to a new, lower frame rate, higher resolution format, and the debate will continue.



Actually, even in the digital world, there is an issue with interlacing. De-interlacing doesn’t just “lien double” the picture. It actually has to interpolate between lines that have different timing. It’s that difference in timing between odd and even numbered scan lines that introduces some potential loss of crispness to the picture. Having said that, it’s very doubtful that the average consumer watching average HD programming on an average HDTV would even notice. The biggest advantages of 1080i over 720p are two things: One, the increase in horizontal pixel resolution from 1366 to 1920, and two, one less step in converting the resolution since a 1080p HDTV is going to be able to display pixel-for-pixel the incoming 1080i signal, where the 720p signal is going to have to go through a conversion to the native resolution of the screen (likely either 1920x1080 or 1366x768).

#38 OFFLINE   Sirshagg

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Posted 18 June 2008 - 03:12 PM

The future of 1080p broadcast is here - XstreamHD !
And reading old threads will give more facts - http://dbstalk.com/s...ad.php?t=115434


Really? still looks like vaporware to me. Albeit very sexy vaporware.
Who is this "Vod Kanockers" that you speak of?

#39 OFFLINE   John in Georgia

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Posted 18 June 2008 - 04:10 PM

Anyone think that this BSS could ultimately end up in me having to actually look at purchasing a 1080p TV for my DirecTV services? I understand 1080p is not even broadcast in the US as of a few days ago...

Currently I just stick with 720p for DirecTV as I did not think the chance for 1080 would happen on DBS, or the "latest" revelation of BSS (that Tom pointed out over a year ago).


I currently have DirecTV HD and Blu-Ray as video sources. I enjoy motion sports and have a 720p CRT and a 1080p DLP. If I were buying today, it would definitely be 1080p.

John

#40 OFFLINE   cartrivision

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Posted 18 June 2008 - 09:06 PM

So do you want 30 frames per second, or 60 frames per second? If bandwidth is no consideration, everyone would say 60. But if every 2nd frame is a repeat of the previous one, do you really care? Films are 24fps. That can't be upconverted unless you speed the film up. So the vast majoriy of Hollywood films don't look any better in 1080p than they do in 1080i.

Movies are 24fps, so the 1080i format has that covered when upconverted to 1080p. In fact, I think Blu-Ray being 1080p(60) is a marketing thing. How can a 1080 line, 24 fps image, look better when reproduced on a 1080 line 60 fps display, vs. a 1080 line 30 fps display?


It can't and that's the dirty little secret of 1080p. For the way 1080p is used by most people more than 90% of the time... to watch 24fps film source material on Blu-Ray discs... delivering the video as 1080p provides ABSOLUTELY ZERO benefit over delivering it in 1080i, as long as the 1080i video is properly deinterlaced.




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