High-Def FAQ: What's the Big Deal About 1080p24?

[jed]

You've heard about it, but do you really know what's behind the latest buzzword in high-definition? In his latest column for HDD, Josh Zyber offers up a primer on 1080p24:

http://www.highdefdigest.com/news/show/1015

[guyver2077]

thanks for the info.

Now are there tv's that currently support 1080p24?

[ddwyer]

Good article - thanks, Josh. I've heard that in some cases, players that offer so-called 1080/24p output introduce the 3:2 pull-down and then 'undo' it, so to speak to send it out at 24hz - is there any truth to that?

[ddwyer]

Originally Posted by guyver2077

thanks for the info.

Now are there tv's that currently support 1080p24?

I think some of the higher-end Pioneer plasmas do. I have one that does 768p24 but it's an older model.

[atdm71]

Very informative. Articles like this one and the HDMI specs, in my opinion, are where we find the author at his finest.

[mrkiller]

some new TV's have 24p but i heard most of them actually make the judder worst (the 120hz ones)

[rick240]

I'd be curious to know if TVs that display 1080p24 directly duplicate the frames (displaying them at 48 fps, effectively 2:2 pulldown).

If not, the likelihood of jitter artifacts is high as 24 fps is not adequate for our eyes to blend images.

Movies are in fact displayed on projectors that have two openings to cause each frame to be displayed in front of our eyes twice during its 1/24th of a second (giving us 48fps displayed from a 24 fps source) so that our eyes will blend the images and not detect a 24 fps flicker rate.

Any TV manufacturer that builds a 1080p24 capable display that doesn't actually display at 1080p48 has made a HUGE mistake.

[Nismo]

Originally Posted by guyver2077

thanks for the info.

Now are there tv's that currently support 1080p24?

Sony has several new 1080p24 (120Hz) HDTV's coming soon. These new models will eliminate the need for 3:2 pulldown conversion when viewing 24fps content (film—DVD, HD DVD & Blu-ray). With content, player & now displays all native 1080p24, with no conversion or additional "processing" required... that's a good thing! I have one on pre-order.

Note: Since the display has a 120Hz refresh rate, they also have a new feature which "doubles" the amount of viewable frames when detecting/viewing 60fps content. This will benefit "Behind the Scenes" (and other non-24fps content) with improved/enhanced video quality. And naturally, they will still offer reverse 3:2 pulldown option, if player is not capable of 1080p24 output.

New Model #'s: KDS-Z70XBR5; KDS-Z60XBR5

[Helo]

Thanks for the informative article Josh It was quite helpful. I see better how I misunderstood a few things about 1080p24 in my thread from a week or so ago.. Cheers! Have a good weekend!

[HD Guru]

Originally Posted by rick240

I'd be curious to know if TVs that display 1080p24 directly duplicate the frames (displaying them at 48 fps, effectively 2:2 pulldown).

If not, the likelihood of jitter artifacts is high as 24 fps is not adequate for our eyes to blend images.

Movies are in fact displayed on projectors that have two openings to cause each frame to be displayed in front of our eyes twice during its 1/24th of a second (giving us 48fps displayed from a 24 fps source) so that our eyes will blend the images and not detect a 24 fps flicker rate.

Any TV manufacturer that builds a 1080p24 capable display that doesn't actually display at 1080p48 has made a HUGE mistake.

No tv displays at 48Hz and you're wrong, they haven't made a huge mistake as some sets do have excellent 3:2 pulldown with 1080p/24 sources being accepted and displayed at 60Hz with hardly any noticeable judder at all.

All HDTV's display 60Hz, some have higher settings as well, like the number of new LCD's with 120Hz display. The 120Hz displays still have to RECOGNIZE the 1080p/24 signal though (unless you're playing a video game running at 1080p/60 of course) in order to display it properly and that's why it's so important to research the television you're buying if you want to display 1080p/24 at a refresh rate capable of displaying with no uneven cadence.

The new 1080p KURO series from Pioneer, the PDP-5010FD (50" - $3495 from Plasma Concepts), PDP-6010FD (60" $4495 from Plasma Concepts), Elite PRO-110FD (50") and Elite PRO-150FD (60") all accept a 1080p/24 signal and display it at 72Hz using Pioneer's "Advanced PureCinema" with 3:3 pulldown. Of course they will also display a 60Hz signal at 60Hz too.

As far as I know they're the only plasma's right now on the market to do it, but look for pretty much all new plasma's from Samsung, Panasonic and Hitachi announced at CES 2008 to have 3:3 pulldown too as well as accepting a 1080p/24 source.

Reviews are your friend and Gary Merson (The HD Guru from www.hdguru.com) is contantly testing all these areas of displays for you to benefit from so for cripes sakes take the time to research before buying!!

Is HD still going to look great on your 720p/1080i set with no native 1080p/24 handshaking and no even cadence? Of course it will, but you want the best right? That's why you're reading threads at High Def Digest.

[HD Guru]

Originally Posted by Nismo

Sony has several new 1080p24 (120Hz) HDTV's coming soon. These new models will eliminate the need for 3:2 pulldown conversion when viewing 24fps content (film—DVD, HD DVD & Blu-ray). With content, player & now displays all native 1080p24, with no conversion or additional "processing" required... that's a good thing! I have one on pre-order.

Note: Since the display has a 120Hz refresh rate, they also have a new feature which "doubles" the amount of viewable frames when detecting/viewing 60fps content. This will benefit "Behind the Scenes" (and other non-24fps content) with improved/enhanced video quality. And naturally, they will still offer reverse 3:2 pulldown option, if player is not capable of 1080p24 output.

New Model #'s: KDS-Z70XBR5; KDS-Z60XBR5

Sony already have 1080p/24 sets on the market with 120Hz refresh rate.

Here's a recent review and it's the bits that I'm quoting that are pertinent and a big reason why you need to check reviews, because just saying that it accepts a 1080p/24 signal and has 120Hz capability with 5:5 pulldown doesn't mean everything is going to be lovely jubbly.

http://hdguru.com/?p=131

Exclusive: First Review of the Sony KDL-46XBR4

All 1080i HD broadcasts (CBS, NBC, CW, HBO, Showtime, Discovery HD, HD Net and most of the other HD Networks) must be properly “deinterlaced” (with motion compensation) to 1080p on a frame-by-frame basis in order to properly retain all 1080 lines of resolution on a display. Some 1080p HDTVs “deinterlace” by discarding every other frame, meaning you will see just 50% of the resolution.

I quickly discovered that this Sony does not properly deinterlace 1080i in the factory default “Vivid” picture setting. In fact, it also drops 50% resolution in the “Standard” picture mode as well. However, the set does properly deinterlace the 1080i signal and does deliver all frames, and thus does display the full vertical resolution, in either “Custom” or “Cinema” picture mode!

Why did Sony choose to make the default mode one that fails to properly deinterlace incoming 1080i signals? I haven’t the faintest idea, especially since, according to a number of set makers, the majority of HDTV buyers leave the user settings in the factory default!

If you pick up just one tip from this website, it should be to change your HDTV out of its “showroom default” setting (which may be called “Dynamic” or some other variation) as soon as it is unpacked and connected. The preferred picture setting on most brands will be called “Cinema,” or “Custom,” or “Pro,” or some variation of those. Check your owner’s manual for the choices.

When you select whatever the “advanced” setting is called, it will always deliver a better image under home lighting conditions than the factory default setting, which is intended only for brightly (over)lit dealer showrooms.

The 3:2 cadence test determines if the set’s video processor properly identifies film-based 24fps content and converts it to 60fps (in this and in most 120Hz sets the processor then interpolates and creates an intermediary frame to produce double the frame rate).

This Sony, like most of the 75 2007 models the HD Guru™ tested this year, failed the 3:2 cadence test. Failure results in degraded resolution and/or visible artifacts. Unlike the de-interlace test, where switching picture modes affected the result, the KDL-46XBR4 failed to identify and convert 24fps film-based signal in all picture modes. Silicon Optix’s HQV HD test disc (Blu-ray edition) provided both 3:2 cadence and 1080i de-interlace tests).

This stuff is VERY important folks for all of us who want to know what we're buying. Do you want to get home with a $3999 television just to find out it's going to screw up your 1080i broadcast HD signals in two of the four picture modes? Thankfully the cinema mode works, which hopefully is where you'll have it most of the time.

The 3:2 failure though is NOT GOOD!

However to end:

Bottom line, this Sony, properly adjusted, produced the best LCD flat panel HD image the HD Guru™ has seen to date. A number of factors are responsible. This panel creates some of the deepest blacks and the best contrast ratio seen on an LCD display. The Samsung/Sony SPVA LCD panel it uses, is, in the HD Guru™’s opinion, is the best LCD panel in the industry. Within the LCD category, the HD Guru™ awards the KDL-46XBR4 ♥♥♥♥.

However, compared to other flat panel HDTVs, regardless of technology, the rating drops down to ♥♥♥, simply because the best plasma TVs produce better images, with better reds, wider viewing angles, and significantly better motion detail and usually for less money!

So why are consumers passing on better performing plasma TVs and spending more money (per inch screen size) for poorer performing large screen LCDs? Because they produce brighter pictures and consumers mistakenly believe “brighter is better.” However, unless one lives in a retail showroom or has set up an ultra-bright, high ambient light viewing environment that mimics a showroom, the HD Guru™ cannot understand why anyone would pay more to buy a top-rated LCD set when a less expensive top-rated plasma set will outperform it while still providing up to three times more light output than necessary in any typical home environment.

The end result? GO PLASMA! You won't regret it especially with the prices you can get now.

[Nismo]

Originally Posted by HD Guru

This stuff is VERY important folks for all of us who want to know what we're buying. Do you want to get home with a $3999 television just to find out it's going to screw up your 1080i broadcast HD signals in two of the four picture modes? Thankfully the cinema mode works, which hopefully is where you'll have it most of the time.

I have the current 60" SXRD XBR model. I only use one picture setting for each of the 7 video labels....the "custom" label. Each one, independenty calibrated for the assigned source device. I would never use the "vivid" or any other artificial picture setting (they offer only half the options when cailbrating, and look terrible by comparison). Besides, who uses the default settings anyway??

The 2 new SXRD models I mentioned....are not out yet (70" KDS-Z70XBR5; 60" KDS-Z60XBR5). They will both offer 2 options when they detect content that is not recorded @ 24fps. One, it will still offer reverse 3:2 pulldown for 60fps content. And two, they are introducing a new "Motionflow 120Hz" feature which "doubles" the viewable frames when watching non 24fps content.

Even the HD Guru™ said the Sony (KDL-46XBR4/ Bravia LCD line) had the best picture quality he has seen to date. The new XBR5's I mentioned, are Sony's Flagship SXRD models....so my pre-order is still good. Should be even better than the Bravia LCD. Can't wait, no regrets. Your "price" factor argument doesn't make sense. Try buying a 70" Plasma for the same price as the 70" SXRD from Sony, good luck.

[Dirtfiend]

I just wanted to say - great article. It was very informative. Thanks!!

[aredo]

There is quite a lot of confusion regarding the so called "1080p24".. the 24Hz marketing hyped support found on many new plasma and TFT Tv sets nowadays, as well as there is a lot of confusion regarding 3:2 pulldown.

The article author here pointed out the fact that the difference between 1080p at 60Hz and 1080p at 24Hz would be subtle for the majority of people.. can anyone as well as the author wonder why ? Did anyone question that ?

Does anyone remember the old VCRs that were sold worldwide capable of converting between SD video standards and sold in the prosumer market ? They were capable of converting between NTSC-J<->NTSC-US<->PAL<->SECAM and they were pretty expensive for the average guy. Now, those VCRs were using 3:2 pulldown like techniques to achieve the conversion and the result was nice but far from perfect. Due to the simple fact that DSPs at the time were just too expensive and too slow to do the job properly in the consumer/prosumer market segments, the majority of work had to be done in the analogue domain initially. Only later models started including some more advanced digital algorithms to achieve better conversion results.

Since then DSPs raw power kept increasing,even more than doubling, year after year while their cost in end-user products kept falling. So way more advanced motion compensation techniques and respective algorithms were developed and implemented. Motion compensation practically eliminates the need for 3:2 pulldown. Modern systems do not really use bare 3:2 pulldown, practically no one would use any basic pulldown technique when programming video algorithms for coding and filters nowadays. DVD/BD/HD-DVD players as well as plasma and TFT Tv sets just use some implementation of motion compensation algorithms at different levels of precision and with various added filters to improve the final result. This result quality can vary a lot between manufacturers, there is not just a kind of motion compensation algorithms that can be studied in developers books, and many manufacturers do develop and/or heavy modify known ones directly in-house to make their products better than the competition.
This is the main reason why nowadays you generally can't see any real improvement at watching bare 24Hz video frames. High-end projectors in theatres use motion compensation/motion estimation techniques to create true 48Hz/72Hz video which makes the film a lot smoother.
Why the result of motion compensation algorithms on your Tv sets is inferior to what you watch in a theatre then ? Well, it's up to the implementation and hardware costs. Professional and high-end projectors can even have more than one DSP number crunching vectors estimations calculations at very high precision in order to deliver the best possible results while even the most expensive Tv sets are still less expensive than many projectors that usually even come with an external rack of video-processors doing all the number crunching tasks at insane speeds that even an high-end server couldn't match. It's as simple as that. Better the quality you want to achieve, more calculations are needed indeed to lower estimation errors and increase actual SNR in both spatial and temporal domains.

These are some of the basic reasons why using bare 24Hz is not as good as the marketing guys want you to believe and the reason why watching movies at 50/60Hz or 100/120Hz (if they support those) on your plasma/TFT displays is actually far better and to the majority of people could look as good as high-end projectors, although technically it's not (unless comparing to quite old projectors/video processors combo). But anyway everything is still up to the algorithms implementation, even a small coding bug could cause some pretty bad results. Now, if only Tv sets manufacturers would put updated bug-fixed firmwares for their displays on their web sites and allow end users to do the updates by themselves.. then things could improve for many, as long as the manufacturers would actually fix coding issues--and there always are some just like on any other firmware on any hardware device.

Here is a US Patent filed by Lucent in 1998 that was already using motion-compesation techniques to deliver smoother and higher quality frame rate conversions:

----

no_spam_vvv.google.com/patents?id=r5wGAAAAEBAJ

Motion compensation image interpolation--frame rate conversion for HDTV
Kobad Bugwadia et al

Abstract
A process for up-converting an existing video source signal having a low frequency (frames/second) to a high frequency signal for use with High Definition Television (HDTV). The process samples the existing frames in the existing video signal and calculates integer displacements of pels within the existing frames. A polynomial curve fit is then performed on the displacements to obtain estimates of horizontal and vertical displacements of each block in each existing frame. Based on the alignment of the blocks within a sampling grid on each frame, the blocks are segregated into groups. The block groups are then used to interpolate missing or required frames of the high frequency signal in a piecemeal manner by utilizing blocks of a particular block group to estimate a corresponding block in a frame of the high frequency signal.

Patent number: 6229570
Filing date: Sep 25, 1998
Issue date: May 8, 2001
Inventors: Kobad Bugwadia, Eric D. Petajan, Narindra N. Puri
Assignee: Lucent Technologies Inc.
Primary Examiner: Jean W. Desir

-----

[HD Guru]

Originally Posted by Nismo

The 2 new SXRD models I mentioned....are not out yet (70" KDS-Z70XBR5; 60" KDS-Z60XBR5). They will both offer 2 options when they detect content that is not recorded @ 24fps. One, it will still offer reverse 3:2 pulldown for 60fps content. And two, they are introducing a new "Motionflow 120Hz" feature which "doubles" the viewable frames when watching non 24fps content.

Even the HD Guru™ said the Sony (KDL-46XBR4/ Bravia LCD line) had the best picture quality he has seen to date. The new XBR5's I mentioned, are Sony's Flagship SXRD models....so my pre-order is still good. Should be even better than the Bravia LCD. Can't wait, no regrets. Your "price" factor argument doesn't make sense. Try buying a 70" Plasma for the same price as the 70" SXRD form Sony, good luck.

The models you've mentioned are not out yet, that is correct, but the 120Hz Motion Flow technology is on several of Sony's sets already (and Samsungs and Sharps and Toshibas)

HD Guru did NOT say the 46XBR4 is the best picture quality he's ever seen, he said it's the BEST LCD picture quality he's ever seen. MASSIVE DIFFERENCE!

Perhaps the HD Guru was not clear enough regarding his reasoning. This Sony raises the bar for LCD flat panels, but in terms of overall performance, especially motion resolution, the best LCDs still don’t measure up to the best plasmas (or microdisplays in terms of motion). If the Sony was given four hearts instead of three it may have misled readers to believe it is just as good as the best plasma in terms of overall performance. I felt I needed to make the comparison against all HDTVs Thanks for the input.

The HD Guru

So why are consumers passing on better performing plasma TVs and spending more money (per inch screen size) for poorer performing large screen LCDs? Because they produce brighter pictures and consumers mistakenly believe “brighter is better.” However, unless one lives in a retail showroom or has set up an ultra-bright, high ambient light viewing environment that mimics a showroom, the HD Guru™ cannot understand why anyone would pay more to buy a top-rated LCD set when a less expensive top-rated plasma set will outperform it while still providing up to three times more light output than necessary in any typical home environment.

Great 1080p plasma sets from the most reliable plasma maker according to consumer reports - 50" 1080p only $2149

http://amazon.com/gp/product/B000QDB...pf_rd_i=507846

Plasma is the best picture technology available - hands down.

And again, just because a manufacturer SAYS what a set is going to do, doesn't mean it actually does it when you get it on the test bench.