# 1080P 24hz vs 60hz ??



## Tybee Bill (Oct 21, 2008)

Saw a thread that said the 0x290 will work with 24hz TVs only.
Called Sharp CS about my 65" model LC65D64U and they said it is a 60hz receiver and that it will work with the new D* 1080P output.
I called D* HD tech support and they confirmed the new version and my HR22 and HR20 would work with this TV.
The TV arrives on Tuesday.

What should I expect?


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## jdspencer (Nov 8, 2003)

Well, it will work just fine!

Or not!!

Sorry, couldn't resist.


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## davring (Jan 13, 2007)

Most newer sets I have checked out on line have the specs published. Not many yet do support 1080P24.


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## Tybee Bill (Oct 21, 2008)

jdspencer said:


> Well, it will work just fine!
> 
> Or not!!
> 
> Sorry, couldn't resist.


See on your profile that you have waivers for HD locals. I had them also for years and they cancelled them a few weeks ago. They also told me that the HR10-250 wouldn't get any HD soon. They offered me a free HR22-100. I took it.


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## Tybee Bill (Oct 21, 2008)

davring said:


> Most newer sets I have checked out on line have the specs published. Not many yet do support 1080P24.


The D* guy promised and the Sharp guy gave me a case number to back up his promise.

We shall see.


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## evan_s (Mar 4, 2008)

Unless the TV support 24p as an input it won't work with directvs 1080p output. If it doesn't support a display refresh rate that is a multiple of 24 then it won't matter, eg 48 or 72 HRz etc. The only real benefit of 24p is the ability eliminate irregular repeating pattern that gets used to convert 24p to 60i.


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## LameLefty (Sep 29, 2006)

Tybee Bill said:


> The D* guy promised and the Sharp guy gave me a case number to back up his promise.
> 
> We shall see.


Okay here's the deal: unless the set ACCEPTS a 1080p/24 signal, you will not be able to use it for 1080p/24 VOD material from Directv. That's the fact.

However, the _additional_ fact is that there are only a bare handful (two, last I saw) 1080p VOD programs even available. Most current 1080p sets (mine included) accept only 1080p/60 signals. All broadcast HD material is either 1080i or 720p so if your set accepts either or both of those it will work just fine for all real-world purposes.


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## eahmjh (Dec 2, 2006)

Why oh why did DTV do update to the HR2x line of HD DVR and a very few of the TV's only support 1080p24. Why didn't they work on the 1080p60 first then 1090p24. That seems bass ackwards.


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## LameLefty (Sep 29, 2006)

eahmjh said:


> Why oh why did DTV do update to the HR2x line of HD DVR and a very few of the TV's only support 1080p24. Why didn't they work on the 1080p60 first then 1090p24. That seems bass ackwards.


The chipsets of the HR2x series cannot decode and display 1080p/60 source material, that's why.

For that matter, most 1080p/60 sets are things like LCD and DLP sets that internally convert all signals (even from 480i material) to 1080p for display anyway.


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## davring (Jan 13, 2007)

eahmjh said:


> Why oh why did DTV do update to the HR2x line of HD DVR and a very few of the TV's only support 1080p24. Why didn't they work on the 1080p60 first then 1090p24. That seems bass ackwards.


They chose 1080P24 because it requires no more bandwidth than the 1080i60 they now use. 1080P60 could not be broadcast with the equipment used today.


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## yyygac2 (Jul 12, 2008)

Tybee Bill said:


> Saw a thread that said the 0x290 will work with 24hz TVs only.
> Called Sharp CS about my 65" model LC65D64U and they said it is a 60hz receiver and that it will work with the new D* 1080P output.
> I called D* HD tech support and they confirmed the new version and my HR22 and HR20 would work with this TV.
> The TV arrives on Tuesday.
> ...


I would expect it to play ... at 1080i


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## Anaisa (Sep 6, 2008)

eahmjh said:


> Why oh why did DTV do update to the HR2x line of HD DVR and a very few of the TV's only support 1080p24. Why didn't they work on the 1080p60 first then 1090p24. That seems bass ackwards.


The movies are produced in 1080p24, even if the chipset could support both formats DIRECTV should have prioritized the one they did. No one here believes the chipset in our boxes supports 1080p60 (neither ATSC does by the way...).

It is likely that the TV manufacturers picked 1080p60 because it was cheaper to produce (they already had the 60Hz oscillator for 1080i60, 720p60, etc).

My goal is to get the best possible picture quality, I applaud the 1080p24 introduction. All users should, even the ones without 1080p24 TVs. A movie transmitted in progressive format and converted to interlaced in the box will have better video quality than a movie transmitted in 1080i. I know some of you will dispute this statement,  , but I know what I am talking about  .


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## BattleZone (Nov 13, 2007)

Movies are shot at 24 frames per second on film, so when they are encoded for HD, film sources are encoded at 1080/24p.

If your TV doesn't accept 1080/24p input signals, the receiver will convert the video to 1080/60i.

If your TV supports 1080/24p input signals, but has a fixed 60Hz display panel (or otherwise can't display 24p content at an even multiple of 24), then your TV itself will convert the 1080/24p signal to 1080/60i internally.

If your TV both supports 1080/24p input signals, and has a refresh mode that is a multiple of 24 (48, 72, 96, or 120Hz), then you get all of the benefit of the format: you will get to see each frame on screen for 1/24th of a second, in progressive scan format.

Only a handful of 2007 models, and a larger number of high-end 2008 models support proper 24 fps refresh, but I expect that it will be a standard feature on all TVs in the next couple of years.


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## smokey99 (Oct 22, 2007)

The Sony KDL-46W4100 that I purchased last month accepted it fine. My three year old plasma wouldn't though.


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## skylox (Aug 10, 2008)

I have a Vizio 1080p and my HR22 has no problems with the 1080p output....so, since I had a 1080p recording on my dvr I tried it and my tv switched right to 1080p and played the video fine.....except it wasnt in 24p I know that...
But I do feel bad for some people since I have a budget hd tv and others who have spent way more on a tv can't get 1080p


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## houskamp (Sep 14, 2006)

My 5mo old sharp LC52D92U won't play the 24 from directv..


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## Bosox07 (Feb 2, 2008)

Tybee Bill said:


> What should I expect?


I would expect it to not work. I have a 42D64U in the bedroom that says the signal in not compatible when I try to view the 1080p/24 content.


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## schneid (Aug 14, 2007)

evan_s said:


> Unless the TV support 24p as an input it won't work with directvs 1080p output. If it doesn't support a display refresh rate that is a multiple of 24 then it won't matter, eg 48 or 72 HRz etc. The only real benefit of 24p is the ability eliminate irregular repeating pattern that gets used to convert 24p to 60i.


60hz displays use a 2/3 pull down to handle 24fps. Read here:

http://en.wikipedia.org/wiki/24p


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## schneid (Aug 14, 2007)

IIP said:


> Movies are shot at 24 frames per second on film, so when they are encoded for HD, film sources are encoded at 1080/24p.
> 
> If your TV doesn't accept 1080/24p input signals, the receiver will convert the video to 1080/60i.
> 
> ...


I agree that it will be the standard and that is why 120hz displays are hitting the market as they can handle even multiples of 24. My discontinued Samsung BD player pushes 1080p/24 as does the mid-level video card in my HTPC. I doubt these manufacturers wouldn't be including it unless it was going to be necessary.

That said, my eyes are not fine tuned enough to see the difference between a Blu-ray DVD at 24fps or 60.


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## Starchy77 (Jul 18, 2008)

Tybee Bill said:


> Saw a thread that said the 0x290 will work with 24hz TVs only.
> Called Sharp CS about my 65" model LC65D64U and they said it is a 60hz receiver and that it will work with the new D* 1080P output.
> I called D* HD tech support and they confirmed the new version and my HR22 and HR20 would work with this TV.
> The TV arrives on Tuesday.
> ...


I have the 52" model of this TV - it will work with the D* 1080p movies - you should not have any problems.


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## Vinny (Sep 2, 2006)

My Panasonic TH-50PZ85U plays the 1080p movies from DirecTV with no problem. I looked at the TV specs online and I see; *24p Playback(2:3)*...what does that mean?


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## schneid (Aug 14, 2007)

Vinny said:


> My Panasonic TH-50PZ85U plays the 1080p movies from DirecTV with no problem. I looked at the TV specs online and I see; *24p Playback(2:3)*...what does that mean?


2:3 means that to get 24fps to display at 60hz (cycles per second) it shows the first frame twice, the second thrice, the third twice, the fourth thrice, and so on up to sixty frames.

For a more academic explanation, read here:

http://en.wikipedia.org/wiki/24p


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## evan_s (Mar 4, 2008)

schneid said:


> 60hz displays use a 2/3 pull down to handle 24fps. Read here:
> 
> http://en.wikipedia.org/wiki/24p


And as I said the only real benefit of 24p is to avoid the need to do a 2/3 pull down.


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## evan_s (Mar 4, 2008)

Vinny said:


> My Panasonic TH-50PZ85U plays the 1080p movies from DirecTV with no problem. I looked at the TV specs online and I see; *24p Playback(2:3)*...what does that mean?


I assume it means it can take a 24p input but will just do it's own internal conversion to 60i or 60p and you don't see it as a multiple of 24hz so don't get any real benefit from it.


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## Vinny (Sep 2, 2006)

schneid said:


> 2:3 means that to get 24fps to display at 60hz (cycles per second) it shows the first frame twice, the second thrice, the third twice, the fourth thrice, and so on up to sixty frames.
> 
> For a more academic explanation, read here:
> 
> http://en.wikipedia.org/wiki/24p





evan_s said:


> And as I said the only real benefit of 24p is to avoid the need to do a 2/3 pull down.


Thanks guys. Very informative reading.


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## TomCat (Aug 31, 2002)

IIP said:


> Movies are shot at 24 frames per second on film, so when they are encoded for HD, film sources are encoded at 1080/24p.
> 
> If your TV doesn't accept 1080/24p input signals, the receiver will convert the video to 1080/60i.
> 
> ...


Here's the post that wins the "most clear and informative" award for this thread.

But what does that mean regarding how one might be better than another?

The potential benefits of 1080p24 over 1080i30 are twofold:

1) 1080p24 has no interlace error, just like 720p has no interlace error, while most 1080i30 does.

2) Pulldown for 1080i30 means that odd frames of the film will be displayed twice (progressively) followed by even frames of the film being displayed 3 times (also progressively). So essentially, the first image shot at 1/24th of a second will be displayed for 2/60ths (or 1/30th) of a second followed by the second image shot at 1/24th of a second being displayed at 3/60ths (or 1/20th) of a second. This means that for TV sets without the ability to refresh at a multiple of 24 and instead using pulldown, there will be a very minute and very-likely invisible amount of judder, as opposed to those that can refresh at such multiples which will not induce the judder.

The really interesting part of this is that 1080i30, which is what is typically delivered OTA or by DVB sat, can be reconstructed into true 1080p also without interlace error, and is exactly what happens every time a movie or other 24 fps content is broadcast in 1080i. This is a function of the "film mode" aspect of ATSC, and has been the way every 1080i movie has been delivered since 1998 and is part of every ATSC encoder or decoder ever manufactured. DVB has a similar capability.

That means that for those who have sets that do not refresh at multiples of 24, the quality of any garden-variety movie ever broadcast at 1080i is precisely the same as that delivered by DOD or Blu as 1080p24, assuming all else is held equal. Put another way, 1080p24 is not really any better than 1080i when movies are broadcast other than the judder issue (which is a non-issue and still there in both 1080i30 and 1080p24 in all non-multisync sets) which is mostly undectectable anyway. This also applies to all content from the NFL channel, all of which is based at 24 fps. (Note, "film mode" does not improve 1080i30 from non-24 fps content, and it is indeed minutely inferior to 1080p24).

All of that seems to make any fuss over 1080p movies much ado about absolutely nothing for those who don't have 24 fps multisync sets, and would provide very little increase in likely-undetectable quality at all even for those who do have such sets. If you could even detect it, that tiny amount of judder might appear as a mild pulsation during very slow pans and zooms, and would be completely undetectable otherwise.

Actually, there is very little difference between 720p and 1080i30 which have virtually identical perceived resolution (after all, who among us can really tell the difference other than those who have fooled themselves into believing they can) and there is even less difference between either of those and 1080p24. The real increase in quality (and its highly debatable whether that would even be a significant increase) would be in the 1080p60 format, a format that will likely never be broadcast or delivered by sat in the foreseeable future, and will be impractical to download until download speeds at least double or triple from the fastest speeds available today.

So 1080p as a consumer issue seems to be the functional equivalent of the green magic markers that were sold for $20 a pop in the 90's that were supposed to make your CDs sound better if you ran the marker around the outside and inside edges (the theory being that it absorbed the red laser light and kept it from being reflected back through the disc). IOW, mostly useless hype. It's nearly as sad, as well, seeing folks jump through all these hoops for microsopic or no benefit in quality.

I blame DISH, and I also blame DTV for thinking they had to respond to DISH.


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## JonW (Dec 21, 2006)

In reality the 1080p24 option allows DirecTv to distribute video in a very high quality format (near Blu-Ray) that can if necessary be converted by the DVR to other formats (1080i, 720p, 480, etc). 

Like all new things, it's success will depend on how wide spread its use and whether they maintain high quality or start over-compressing.

If all HD movies were eventually broadcast as-is in 1080p24, it'd be a miracle - but technically it's now possible.


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## Tybee Bill (Oct 21, 2008)

Just tried my HR20 with a Sanyo DP4284. HDTVsolutions says it is 1080p_60.
Sanyo.com says it is 1080p (all signals converted to 1080p).
I turned Native off and selected 1080p only and it worked.


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## DarinC (Aug 31, 2004)

IIP said:


> If your TV both supports 1080/24p input signals, and has a refresh mode that is a multiple of 24 (48, 72, 96, or 120Hz), then you get all of the benefit of the format: you will get to see each frame on screen for 1/24th of a second, in progressive scan format.


Although this _should_ be the case, unfortunately there are a surprising number of sets that don't display 24hz material properly despite being capable of refresh rates that are a multiple of 24. This is particularly true of many 120hz sets. Even though the logical thing to do is a 5:5 pulldown, many do a 3:2 pulldown, then multiply that by 2 to get to 60hz (so essentially, a 6:4 pulldown). The marketing of many 120hz sets has focused on speed (being able to handle fast motion), and apparently many haven't bothered updating the pulldown circuits to take advantage of the higher refresh. I guess sports sells better than movies. Or at least video lag/blurring is easier to explain to the layman than judder. There are pages at AVS and other sources dedicated to tracking those that do and don't handle 24fps content correctly, but sometimes getting confirmation of a particular sets is difficult.


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## reber1b (Jun 14, 2007)

Anyone know the refresh rate on a Sharp Aquos LC-60C46U, or where I can find that info? The printed manual does not show the refresh rate on the Specs page.


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## Tybee Bill (Oct 21, 2008)

reber1b said:


> Anyone know the refresh rate on a Sharp Aquos LC-60C46U, or where I can find that info? The printed manual does not show the refresh rate on the Specs page.


Suppose to be 1080p60 like mine (according to Sharp CS) but HDTVsoulutions might tell you it is both 24 and 60. D* swears that mine will work with the new 1080p output. If you own it, try it. My new TV won't arrive until Tuesday.


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## reber1b (Jun 14, 2007)

Tybee Bill said:


> Suppose to be 1080p60 like mine (according to Sharp CS) but HDTVsoulutions might tell you it is both 24 and 60. D* swears that mine will work with the new 1080p output. If you own it, try it. My new TV won't arrive until Tuesday.


Thanks Tybee, I'll VOD one of the titles on Ch 1002 and see how it looks. I found some info while Googling, that my Aquos (LC-60C46U) is Costco's version of the LC46D62U.


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