I have the feeling that the manufacturers don't think this is an important question at all. They use 1080p as a marketing point, but no mention is being given of how that 1080p is being handled and displayed.

However, video guru Joe Kane is very concerned about that, as we can see from an interview (http://blogs.technet.com/hddvd/archive/2006/09/26/459312.aspx) he did with Microsof's Ben Waggoner. Some sections follow:

The most important thing to me is I can tell you that the most efficient way to encode film-based information is to encode it as 24 pictures per second. But that offers opportunities to me in playback, in trying to do the presentation. First of all, I think the idea of a player playing back 24p -playing it back or not playing it back- I'm actually in favor of talking to all manufacturers of players. I don't care if it's Internet download. Actually, in the computer domain right now, playing back 24p is fairly straightforward.

So as an example, you claim that the other camp- you discuss that the other camp is discussing how they're delivering 24p and of course we know they're not. At least in the first generation of players, the 1080p24 that's on the disc is being converted to 1080i60 and then being converted back to 1080p24. There is a potential of harm happening in this double conversion. Actually, the same double conversion could happen in a player that only put out 1080i because you would also do the same transformation back.

I am actually pushing really hard to have player manufacturers provide a true 24p output. I do not want the 24p that's on the disc to be processed. I want it to be handed out in the native format.

[...]

The most important point that I wanted to bring up with 24 is that in the US world, we normally convert that to 60 and add the 2-3 motion where there is judder. I'm actually going to all manufacturers that I'm working with and telling them they have to be able to accept this 24p as an input and then they have to be able to play it back as 24, 48 or 72, so there is no 2-3.

[...]

As much as I have been working with Microsoft, I'm also working outside of Microsoft so that what you produce in source video can look even better to the consumer than they have ever seen it before, and playing back in 24, 48 or 72 is a critical part of what I'm trying to make happen.

[...]

I honestly believe I'm in this for the consumer. I honestly believe that I'm trying to advocate for the consumer what the consumer should have. I don't think the consumers actually do know for themselves what they should have, and I'm actually trying to be an advocate for what they should have.

First-hand testimony (http://www.avsforum.com/avs-vb/showthread.php?t=731434) of native 24 in action during the CEATEC fair in Japan:

It also was the first time I saw a player which can do 24-frame output and also had a TV which could input that 24 frames. so for the very first time no pulldown stuff to 60i etc., just the real video on disc and output. And oh boy does it look good!!!!

...you discuss that the other camp is discussing how they're delivering 24p and of course we know they're not. At least in the first generation of players, the 1080p24 that's on the disc is being converted to 1080i60 and then being converted back to 1080p24.Is it confirmed that all first generation players will do this? Or is Kane talking out his....?

Isn't judder-free p24 an oxymoron? :p (Yes, I agree p24 support on LCD's would be a good thing, but not the end all fix to addressing poor frame rate.)

At least in the first generation of players, the 1080p24 that's on the disc is being converted to 1080i60 and then being converted back to 1080p24.I get the feeling that Joe might be confused and that what he is referring to is really:
At least in the first generation of players, the 1080p24 that's on the disc is being converted to 1080i60 and then being converted to 1080p60.I haven't heard of any players supporting 1080p24 output that are going to 1080i60 first, but I do understand that the Samsung goes to 1080i60 before 1080p60.

Maybe Joe just mixed 2 concepts together. Or maybe one of the 1080p24 output players (like the Pioneer) is converting to 1080i60. I doubt it though.

--Darin

My freind at Cedia talked to Joe Kane personally at the Samsung area, and he used the second phrasing during his conversation.

I just think he mispoke or was misquoted in the interview, he knew very well that the Sammy only outputed 1080p/60.

Can anyone describe what judder-free 1080p24 video looks like? Is it more detailed or just a smoother picture during pans/ fast motion? (Yes... I used wikipedia, but what I found there didn't make too much sense).

When converting 24p for presentation at 60 Hz, this will introduce a 6 Hz difference component (30 fps - 24 fps). This effect can be noticeable as a judder during pans.

By having genuine 24 Hz support in the display, this 6 Hz difference component can be avoided. It is essentially one step closer to seeing it as it was shown in a real projection theater.

This does not mean that all forms of judder during pans are solved, however. There will still be a jerky component to film as long as it remains as a 24p format.

When converting 24p for presentation at 60 Hz, this will introduce a 6 Hz difference component (30 fps - 24 fps). This effect can be noticeable as a judder during pans.

By having genuine 24 Hz support in the display, this 6 Hz difference component can be avoided. It is essentially one step closer to seeing it as it was shown in a real projection theater.

This does not mean that all forms of judder during pans are solved, however. There will still be a jerky component to film as long as it remains as a 24p format.

Ok... makes sense. And then supposedly if you take this signal and display it at 48, 72, or some other multiple of 24 Hz, it will be less jerky?

Is it confirmed that all first generation players will do this? Or is Kane talking out his....?
Yes, it is confirmed, none of the first generation players that are out now will output 24p. Goes for both camps. And before anyone points this out, I am talking about stand alones devices, not laptops.

-Mark

When converting 24p for presentation at 60 Hz, this will introduce a 6 Hz difference component (30 fps - 24 fps). This effect can be noticeable as a judder during pans.

By having genuine 24 Hz support in the display, this 6 Hz difference component can be avoided. It is essentially one step closer to seeing it as it was shown in a real projection theater.

This does not mean that all forms of judder during pans are solved, however. There will still be a jerky component to film as long as it remains as a 24p format.

Actually, it should be a 12 Hz judder (60 - 48). No-one displays at 30 fps (or shouldn't), they do 60 instead. If they did 30, you would have 6 Hz judder, but it wouldn't be 3:2 timing pattern. It would be nasty -- 6 frames per second would have to display double the time (a 2:1:1:1 pattern)! Now that would be terrible judder!

Ok... makes sense. And then supposedly if you take this signal and display it at 48, 72, or some other multiple of 24 Hz, it will be less jerky?

At multiples, it will be exactly the same wrt motion smoothness. The multiples are more relevant for crt-based displays which need a certain refresh rate to prevent flicker issues. 24 Hz would be too low, but 48+ is usually sufficient for smooth lighting output. Some low latency CRT's may even need 72 Hz to become flicker-free.

Ok... makes sense. And then supposedly if you take this signal and display it at 48, 72, or some other multiple of 24 Hz, it will be less jerky?
The key is making sure that source frames of equal duration turn into display times of equal duration.

Displaying 24p content at 60i/pi means that half the film frames are displayed for 2/60th of a second, and the other half are displayed for 3/60th of a second. So, a smooth pan comes out with a jerky "judder." 60i/p doesn't matter at all for judder. What we want is to have each film frame to be displayed for the same amount of time. 24, 48, 72, etecetera doesn't matter for most display types (obviously refresh rate is a big factor for CRT).

If anyone gets a chance to check out our HD DVD truck tour, you'll see HD DVD being played out as 48 Hz through a great Marantz projector. No judder, and without the flicker of a 2-blade projection system. Very, very nice stuff.

Note that the distinction between "native" 24p and inverse telecined 24p is inconsequential as far as the final image goes, since 3:2 removal is an entirely reversible process (basically you insert 12 repeat fields on playback, and then take them out with image processing). Additionally, a properly made HD disc today should be fully compatible with 24p playback in 24p native players (like the aformentioned laptop players).

There's been speculation about whether or not "24p" is going to matter in the format war, but there isn't any practical barrier to doing good 24p with either format.

Actually, it should be a 12 Hz judder (60 - 48). No-one displays at 30 fps (or shouldn't), they do 60 instead. If they did 30, you would have 6 Hz judder, but it wouldn't be 3:2 timing pattern. It would be nasty -- 6 frames per second would have to display double the time (a 2:1:1:1 pattern)! Now that would be terrible judder!

I don't know if 60 vs. 48 applies technically, since 48 contains no more motion information than the original 24. "60" implies interlaced output, which complicates things further wrt how often a full frame occurs. So that is why I maintain that there are 24 fps of material and there are 30 full frames per second under a 60 Hz refresh configuration. Hence, the difference component should correlate to 30-24=6. If you want to go with 12 Hz for the juddered frame, it is still just the same frame repeated twice at 6 Hz.

If anyone gets a chance to check out our HD DVD truck tour, you'll see HD DVD being played out as 48 Hz through a great Marantz projector. No judder, and without the flicker of a 2-blade projection system. Very, very nice stuff.

You guys aren't setting up at any Fry's stores, are you?

but there isn't any practical barrier to doing good 24p with either format.Ron (dr1394) states otherwise for HD-DVD, native 24p output is not in the specs. Has this not been covered in detail?

Ron (dr1394) states otherwise for HD-DVD, native 24p output is not in the specs. Has this not been covered in detail?

24p will be an additional feature for HD DVD players. It has nothing to do with HD DVD spec. Keith agrees with this. I hope this could end the no 24p for HD DVD FUD.

Also, Ron said the decoder couldn't ignore the flag per spec. He didn't say HD DVD player couldn't IVTC 1080i60 to 1080p24.

So what exactly is on the disc on an hdvd?

So what exactly is on the disc on an hdvd?


1080p24 stream with 3:2 sequence header or so called flag for movie source.

Note that the distinction between "native" 24p and inverse telecined 24p is inconsequential as far as the final image goes, since 3:2 removal is an entirely reversible process (basically you insert 12 repeat fields on playback, and then take them out with image processing).

Ben, and yet Joe Kane says: "At least in the first generation of players, the 1080p24 that's on the disc is being converted to 1080i60 and then being converted back to 1080p60. There is a potential of harm happening in this double conversion. Actually, the same double conversion could happen in a player that only put out 1080i because you would also do the same transformation back.

I am actually pushing really hard to have player manufacturers provide a true 24p output. I do not want the 24p that's on the disc to be processed. I want it to be handed out in the native format."


Who is right then? And why are people (including me) seeing different levels of PQ for different IVTC implementations (eg. HQV/Gennum/VP50 Scaler versus Sony Ruby's internal IVTC processing (with no other filter enabled ) ) in combination with 1080i/60 output from HD-DVD if the process "is entirely reversible"? How can we be a 100% sure that nowhere during this "double conversion" (decoding into a 1080i/60 stream, IVTC back to 1080p/24) ANY form of filtering, smoothing, averaging,... "happens". Thats the potential harm that Joe is talking about - and you better believe Joe Kane ;)

Ron (dr1394) states otherwise for HD-DVD, native 24p output is not in the specs. Has this not been covered in detail?
The exact details for how to decode HD DVD @ 24p aren't specified, but it's not hard to do. It's easier than with DVD, and 24p playback has been working well with DVD for years and years.

Who is right then? And why are people (including me) seeing different levels of PQ for different IVTC implementations (eg. HQV/Gennum/VP50 Scaler versus Sony Ruby's internal IVTC processing (with no other filter enabled ) ) in combination with 1080i/60 output from HD-DVD if the process "is entirely reversible"? How can we be a 100% sure that nowhere during this "double conversion" (decoding into a 1080i/60 stream, IVTC back to 1080p/24) ANY form of filtering, smoothing, averaging,... "happens". Thats the potential harm that Joe is talking about - and you better believe Joe Kane ;)

To add, it's one more opportunity for chroma error (ICE and ICP) to creep into the process. If that whole scene can be circumvented with certainty, that is a bonus, imo. :D

I guess the principle in effect here is a variation on the "keep your laws off my uterus" abortion chant. Ours would be "keep your damn, dirty hands off my bitstream!" ;)

Ben, and yet Joe Kane says: "At least in the first generation of players, the 1080p24 that's on the disc is being converted to 1080i60 and then being converted back to 1080p60. There is a potential of harm happening in this double conversion. Actually, the same double conversion could happen in a player that only put out 1080i because you would also do the same transformation back.

I am actually pushing really hard to have player manufacturers provide a true 24p output. I do not want the 24p that's on the disc to be processed. I want it to be handed out in the native format."

Who is right then? And why are people (including me) seeing different levels of PQ for different IVTC implementations (eg. HQV/Gennum/VP50 Scaler versus Sony Ruby's internal IVTC processing (with no other filter enabled ) ) in combination with 1080i/60 output from HD-DVD if the process "is entirely reversible"? How can we be a 100% sure that nowhere during this "double conversion" (decoding into a 1080i/60 stream, IVTC back to 1080p/24) ANY form of filtering, smoothing, averaging,... "happens". Thats the potential harm that Joe is talking about - and you better believe Joe Kane ;)
As he said, there's a potential for harm, not a certainty. A native 24p output would be simpler once displays support it, and native 120 Hz remains my dream goal. But for those who want a great 24p experience today, we know we can deliver it. It'll be cheaper and easier as time goes on, of course.

There's two different angles here - the player perspective, and the format perspective. And a content guy, I'm mainly concerned with what the format can do, not particular CE devices. We're making discs today that'll work fine in future 24p playback systems, and also work fine with IVTC solutions today.

Am I getting this right?

Mutiples of 24 are ideal but 24 itself is too slow. Using a 3:2 pulldown is what's causing the "judder" during scenes that pan.

I'm now more sensitive to this and other IQ features. This is ofcourse good from a quality stand point but bad from a wallet standpoint :)

A native 24p output would be simpler once displays support it, and native 120 Hz remains my dream goal.

There are displays that support it now, like Pioneer plasmas.

Let's not let the player makers off the hook by saying it's OK for them to wait until there are many more displays available that accept 24p. Because the display makers may take the attitude that they won't bother with the cost of adding 24p inputs if the source devices aren't available.

Gary

Am I getting this right?

Mutiples of 24 are ideal but 24 itself is too slow. Using a 3:2 pulldown is what's causing the "judder" during scenes that pan.

Yep, that's it!

We want each frame's displayed duration to be identical. 3:2 pulldown (60i or 60p) doesn't do this, hence judder. Ironically for all the "BD is progressive" hype, it's actually better to use 60i playback than 60p for more systems these days, since they can do inverse telecine with 60i but not with 60p...

Yes, judder matters, and I can see it myself.

However, I have to note that a lot of people do not seem to be able to notice it very well, at least consciously.

I once had my wife at a demonstration where judder elimination was the point (converting to 72P with pull-down removal etc.) We must have watched a scene from Titanic 20 times (the digital pan of the ship flying overhead), and she simply could not see it. She generally can see artifacts when they are pointed out to her (but doesn't care).

Almost no one I know mentions judder as an issue.

What I do think is true is that higher production frame rates would make an incredible difference to almost everyone. Film at 60FPS is incredible! I would like to see 4320p96 as a production standard for Hollywood films. But 24FPS is so poor that the judder is a minor artifact at worst IMHO.

What I do think is true is that higher production frame rates would make an incredible difference to almost everyone. Film at 60FPS is incredible! I would like to see 4320p96 as a production standard for Hollywood films. But 24FPS is so poor that the judder is a minor artifact at worst IMHO.

I would love to see 60fps used too. But, from what I recall from another thread, it will never happen. :(

I'd love to see them pull a measily 30 fps for film or digital capture. It would also sidestep this whole judder issue, as well, w/o breaking the bank for filmstock or digital storage.

I would love to see 60fps used too. But, from what I recall from another thread, it will never happen. :(

I am not so sure.

The studios clearly need to do something to bring theatrical exhibition back into play. Theatres still make a lot of money and also provide the launch pad and validation for other forms of release. 3D, more resolution, and higher frame rates are obvious choices for the direction of technology.

When you see the effect of higher frame rates, you really know you are looking at something.

I cannot imagine there is a technical problem. Moreover, the cost of digital storage is already a joke with 250GB drives selling for $50, and holographic storage just around the corner.

I would love to see 60fps used too. But, from what I recall from another thread, it will never happen. :(
The DCI spec has a mode for 48 Hz (although mainly meant for 2x24 Hz 3D projection). If DCI digital projeciton catches on, I could see someone trying to do a sports or action movie at 48 Hz, and it'd be pretty cool.

And it's semi-easy to make a 24p 35mm print for a 48 Hz DI if needed. 60 to 24 gives us judder the other direction :). Although the 48 fps master probably would use 96 Hz shutter... Maybe shoot a digital 72 Hz shutter to split the difference?

I think eliminating film media altogether is the key to these higher specs. It's no problem with a digital-based design, but achieving these high frame rates with mechanical shutters and dragging film in short tugs at such rates is where it gets impractical. It's not impossible- just impractical as far as expecting every town theater to pick up such equipment. I don't know how much longer film has left as a viable medium (it certainly has tradition and widespread acceptance on its side), but clearly there is a connection with the lack of progress there has been with movie technology wrt framerates.

A native 24p output would be simpler once displays support it

Ben, a lot of the projectors presented at CEDIA support a native 24p output. The Mitsubishi HC5000 displays it in 48 Hz (each image twice). The Sony VW50 displays it in 96Hz (each image 4 times); interestingly enough, when fed 1080i, it 'only' displays it as 1080p60.

Even the lowly Panasonic AX100U (a 720p LCD with $2,999 MSRP) supports 1080p24 (though downscaled to 1280x720, of course). From the Projector Central review (http://www.projectorcentral.com/panasonic_ax100.htm):

Another capability that is new to many of the latest home theater projectors is the ability to accept and display a 1080p/24 signal. The AX100U will accept 1080p/24 as well as the more conventional 1080p/60. The 1080p/24 format is important because it will become a standard feature on many of the new high definition DVD players, HD-DVD and Blu-ray. Indeed, a couple of the Blu-ray players scheduled for release next month already have it.

The benefit of 1080p/24 transmission between the HD player and the projector is that it eliminates the need for 24 frame/sec film material to go through 2:3 pulldown conversion. This conversion has always been necessary to get film to synch with the 60 cycle displays that are part of the NTSC world. But with digital projectors being able to run at 24 Hz (or multiples thereof, 48 or 72 Hz), the conversion to 60 Hz is no longer needed. This will eliminate occasional artifacts such as judder in slow panning sequences and allow a smoother display of the film source. Once we acquire one of the new Blu-ray players with 1080p/24 output, we will do more testing to assess the degree to which this feature actually contributes to any incremental improvement in the viewing experience.


It seems Joe Kane has been talking to Matsushita... and quite convincingly. :)

for me the major difference in watching it on 24 frames was the natural flow. my eys are very sensitive for that. that is why i liked the pioneer so much. everything felt natural. like no signal was specially made stronger. like what is on disc is what you get. no tricks. nothing. just pure blizz.

I think this is an especially important issue for those of us over here in Euro-land. We are used to buttery smooth 25fps movies (yes sometimes with pitch increase, but we are used to that)

So I think many may be in for a nasty surprise when HDDVD /bluray launch to the mainstream over here.

I really don't see the problem in 24p output. I understand the desire to mix in 60i video but most of the time I'm just watching the movie, and I want it as close to the original as possible

As an ordinary viewer and film-goer, I hate the jerkiness of 24 fps film pans. Destroys my sense of being there. I can see judder, but it is less of an issue to me - a second order effect.

Yep, that's it!

We want each frame's displayed duration to be identical. 3:2 pulldown (60i or 60p) doesn't do this, hence judder. Ironically for all the "BD is progressive" hype, it's actually better to use 60i playback than 60p for more systems these days, since they can do inverse telecine with 60i but not with 60p...

However, 24fps is only considered "too slow" for CRTs or other devices that have "decay" between frame refreshes. Digital projectors do not suffer from this. Thus, as long as they refresh at at even multiple of the input rate (24, 48, 72, 96, etc...) then to our eye it looks identical.

Also note that this is separate from the fact than many people think that film running at 24fps is "too slow" to accurately capture some motion, and is an artifact from long ago (I agree).

I'd love to see them pull a measily 30 fps for film or digital capture. It would also sidestep this whole judder issue, as well, w/o breaking the bank for filmstock or digital storage.

So you're ready to sacrifice the "film look" then just because most display manufacturers don't offer proper refresh rates yet?
Going to 30 fps would heavily reduce motion blur - motion in films would start looking TVish.

...

Also note that this is separate from the fact than many people think that film running at 24fps is "too slow" to accurately capture some motion, and is an artifact from long ago (I agree).

I agree, I think the monster that needs to be killed here is the relic of shooting films at 24fps!

I don't think this has anything to do with sacrificing the "film look/feel" since what we know as film today is simply a relic of the past...

I agree.

Also, motion blur, if needed, is still something that can be had via exposure setting or digital effect. The impact to better motion capture would trumpt all, just the same. The "new" film look/feel would simply supercede the "old" film/look feel in favor.

I can't believe nobody has yet tried to defend the 24 fps cinema in this thread! I, just like lots of other people, think that the low bitrate of cinema is part of its "magic", the thing that gives you the feeling that you are looking at something not exactly real. Most people go to the cinema to get away from reality, not to be immersed in it.
I've watched and shown to my friends scenes from The Matrix converted with interpolation from 24 to 60 fps using one of the Intervideo plug-ins, and all of them concluded that it was awful, ruined the film and made it look more like a documentary. Maybe it's just something people are used to, but I clearly would hate to watch movies shot in 60 fps, it's only news, sports and soap I would accept with this framerate. Also, I bet Hollywood is aware that most people feel the same way too and will intentionally keep the 24 frame format.

I can't believe nobody has yet tried to defend the 24 fps cinema in this thread! I, just like lots of other people, think that the low bitrate of cinema is part of its "magic", the thing that gives you the feeling that you are looking at something not exactly real. Most people go to the cinema to get away from reality, not to be immersed in it.
I've watched and shown to my friends scenes from The Matrix converted with interpolation from 24 to 60 fps using one of the Intervideo plug-ins, and all of them concluded that it was awful, ruined the film and made it look more like a documentary. Maybe it's just something people are used to, but I clearly would hate to watch movies shot in 60 fps, it's only news, sports and soap I would accept with this framerate. Also, I bet Hollywood is aware that most people feel the same way too and will intentionally keep the 24 frame format.

I couldn't agree more. This infamous Intervideo filter ("upsampling" 24p to 60p) made any movie look like your regular afternoon soap :rolleyes:

Cinemas 24p is not the enemy here - viewing 24p content at NTSC refresh rates is. Have you guys here ever seen a PAL DVD @ 50HZ? Now compare the same thing to a NTSC DVD played @ 60Hz and you see 3:2 pulldowns horrible face...

Any kind of change from the "norm" is a bit jarring, at first. Showing a letterbox profile on an sd screen can be jarring the first few times you see it. After you see it a few times, you don't notice it at all, once you get into the movie. Whether it looks "odd" at first is no measure of if it is "correct" or not. Then when you go back to the "norm", it's like somebody took away your candy. You wonder how you could have been happy with the "normal" look.

Any kind of change from the "norm" is a bit jarring, at first. Showing a letterbox profile on an sd screen can be jarring the first few times you see it. After you see it a few times, you don't notice it at all, once you get into the movie. Whether it looks "odd" at first is no measure of if it is "correct" or not. Then when you go back to the "norm", it's like somebody took away your candy. You wonder how you could have been happy with the "normal" look.

I'm guessing many people were totally appalled when movies first added voice, or color. But as new technology enabled these things directors started finding ways to use them to very good effect. It takes time but faster movie frame rates are almost certain for the future.

I can hardly wait. ;)

- Tom

I couldn't agree more. This infamous Intervideo filter ("upsampling" 24p to 60p) made any movie look like your regular afternoon soap :rolleyes:


Or the Philips PixelPlus tech (which, to add insult to injury, received an EISA award...).

Anybody know how this technology works? Something that does what this does is intriguing from a data standpoint.

maybe i'm missing something but using some infamous intervideo filter to create 60fps IS NOT shooting at 60fps (of course, noone has said it must be 60fps, i was thinking more along the lines of 48fps...double).

to say that seeing what an intervideo filter has done with 24p source is the same as what you would get by shooting the source at the intervideo filter's output rate would be the same as saying upconverted 480 to 1080 is the same as native 1080 :confused:

Well said!

I had hoped the interview might offer a definitive answer to what happens when material encoded at 1080p24 is converted to 1080i60 in terms of vertical resolution.

It has been reported by various insiders that there is no vertical filtering of the 1080p masters prior to encoding. The question then is what happens when 1080p is converted to 1080i by the video processor in the player? Does the VP vertically filter the 1080i output in order to minimise interline flicker on 1080i displays (CRTs, ALiS plasmas etc)? If so then so called 1080p players which output 1080p via deinterlacing will have compromised vertical resolution. Hence the need for a true 1080p24 output without deinterlacing.

maybe i'm missing something but using some infamous intervideo filter to create 60fps IS NOT shooting at 60fps (of course, noone has said it must be 60fps, i was thinking more along the lines of 48fps...double).

to say that seeing what an intervideo filter has done with 24p source is the same as what you would get by shooting the source at the intervideo filter's output rate would be the same as saying upconverted 480 to 1080 is the same as native 1080 :confused:
Yeah, unless is has the mythical Nyquist Compensator, train wheels are still going to go backwards at > 12 Hz, although they'll go backwards more smoothly :).

60p for movies would definitely be a different aesthetic, and one which a temporal upsampling filter won't give us a full vision of.

I'm personally agnostic on whether it'd be a good thing for "movie" movies. I 'm happy to state that VC-1 will be ready to encode 60p whenever it'll be needed :).

I'm personally agnostic on whether it'd be a good thing for "movie" movies. I 'm happy to state that VC-1 will be ready to encode 60p whenever it'll be needed .

Optimized motion compensation becomes more effective when frame rates speed up (or motion slows down). Thus I'm wondering if, by the time we change at all, we might find it nice to go all the way to 120 FPS and be done with it for awhile. (until we no longer bother with discrete frames)

- Tom

On 48-fps film, recall some discussion here at AVS in the '90s, and references to film critic Roger Ebert praising some MaxiVision 48 (http://www.geocities.com/hollywood/makeup/4303/maxivision.html) productions he'd seen.

Keep seeing small notices that some Hollywood TV studios are capturing some productions at 1080p60, likely using Sony 1500-series cameras (or others) and HDCAM-SR SRW1 decks at 2X for capture or hard drives. All the standard 1080i/p formats use 74.25 MHz image sampling, while 1080p60 uses 148 MHz sampling as a scanning parameter. Doubt if most will distinguish between 1080/60p and 1080p60 nomenclature, though, as well as differentiating between displaying deinterlaced 1080/60i (30i), the broadcast standard, twice, at 60 fps.

My 1080i CRT RPTV displays all HD at 1080/60i, and I've been speculating (http://www.avsforum.com/avs-vb/showthread.php?p=8541039&&#post8541039) lately that some 1080/24PsF tapes, such as Discovery's "Sunrise Earth" series, might have judder, even with mostly static scenes, because of the extra TV fields from 2-3 pulldown. Sunrise images at 1080/60i on my screen, while great visually, definitely lack the fine detail and smooth motion of 'wow-effect' images captured, transmitted, and viewed at 1080/60i, 60 fields per second with no 2-3 pulldown involved. That, of course, includes live 1080/60i (30i) broadcasts. -- John

As an ordinary viewer and film-goer, I hate the jerkiness of 24 fps film pans. Destroys my sense of being there. I can see judder, but it is less of an issue to me - a second order effect.

I completely agree.

One of the first owners of a Sony BDP-S1 player reports (http://www.avsforum.com/avs-vb/showthread.php?p=9017711&&#post9017711):

Just changed it to direct and BOOM 24fps via HDMI to my "pearl" projector. YEAH BABY!

1080p/24fps is pretty damn impressive. Action scenes are much smoother. Pans across the screen are a lot better.

As an ordinary viewer and film-goer, I hate the jerkiness of 24 fps film pans. Destroys my sense of being there. I can see judder, but it is less of an issue to me - a second order effect.

We went to watch a movie after a long gap. The new bond movie in a newer digital theatre. The jerkiness of end credits was telling ....

Can anyone describe what judder-free 1080p24 video looks like? Is it more detailed or just a smoother picture during pans/ fast motion? (Yes... I used wikipedia, but what I found there didn't make too much sense).
I guess many people here have never been to a movie theater :)

1080p24 is certainly nice, but the movie business seems being stuck in stone age, they should move to 30 fps or higher, 24 fps is way too low for any motion. 1080p24 can cure judder, but it's not going to do anything about motion blur.

I guess many people here have never been to a movie theater :)

1080p24 is certainly nice, but the movie business seems being stuck in stone age, they should move to 30 fps or higher, 24 fps is way too low for any motion. 1080p24 can cure judder, but it's not going to do anything about motion blur.

Sad to say that decision (24fps) was made over 70 years ago when they went from silent to talkies. And like most bad decisions it was based on the $$ cost of having to pay for the extra film required to do 30fps in the camera and making 30fps prints.

Back in the early days there wasn't even a set fps as a standard. :eek:

http://www.cinemaweb.com/silentfilm/bookshelf/18_kb_2.htm#3

b2b

Sad to say that decision (24fps) was made over 70 years ago when they went from silent to talkies. And like most bad decisions it was based on the $$ cost of having to pay for the extra film required to do 30fps in the camera and making 30fps prints.

Back in the early days there wasn't even a set fps as a standard. :eek:

http://www.cinemaweb.com/silentfilm/bookshelf/18_kb_2.htm#3

b2b

And we have been suffering with 24fps artifacts ever since! :mad:

I think eliminating film media altogether is the key to these higher specs. It's no problem with a digital-based design, but achieving these high frame rates with mechanical shutters and dragging film in short tugs at such rates is where it gets impractical. It's not impossible- just impractical as far as expecting every town theater to pick up such equipment. I don't know how much longer film has left as a viable medium (it certainly has tradition and widespread acceptance on its side), but clearly there is a connection with the lack of progress there has been with movie technology wrt framerates.

You are raising an excellent issue but I would take a slightly different tack.

We don't have to get rid of film as an EXHIBITION MEDIUM to get to higher frame rates. Digital production could allow higher frame rates, with digital exhibition preserving that rate, but film exhibition being down-sampled to 24fps. If 72fps were the production rate, this would be particularly simple.

We don't have to get rid of film as an EXHIBITION MEDIUM to get to higher frame rates. Digital production could allow higher frame rates, with digital exhibition preserving that rate, but film exhibition being down-sampled to 24fps. If 72fps were the production rate, this would be particularly simple.

Love this idea. But by the time we are often doing 72 Hz production it may no longer be needed anyway.

- Tom

An interesting opinion: during a chat on Home Theater Forum (http://www.hometheaterforum.com/chat/hdvd07.txt), Microsoft's Kevin Collins downplayed the importance of 1080p:

Q.: What is your take on the different resolutions?

<kevincol> All HD DVD movies titles are encoded at 1080P/24FPS. Obviously 1080 has twice the pixels of 720, so the picture on a 1080P display will look better. In regards to 080i vs 1080p output, since all HD DVD movie titles are encode at 1080P/24FPS. There is no discernable difference on a player that outputs 1080i vs 1080p to a 1080P display. This is best illustrated on the HD DVD Mobile Experience were we have the Marantz 1080P PJ using the first Gen TSB HD DVD player at 1080i. I also added in a DVDO VP50 to output 48FPS to the Marantz. Ron, I beleive, saw this on the HD DVD mobile experience when it was in Seattle. I am a very picky HT enthusiast and the picture in the HD DVD mobile experience is the best I have seen anywhere.

Of course, Collins's findings are skewed by the fact that he was using top-notch 1080i deinterlacing during his tests (Marantz VP11S1 with Gennum VXP Video processing onboard and DVDO Iscan VP50).

There are other displays that, when fed 1080i60, display it as 1080p60, which has judder.

An interesting opinion: during a chat on Home Theater Forum (http://www.hometheaterforum.com/chat/hdvd07.txt), Microsoft's Kevin Collins downplayed the importance of 1080p:



Of course, Collins's findings are skewed by the fact that he was using top-notch 1080i deinterlacing during his tests (Marantz VP11S1 with Gennum VXP Video processing onboard and DVDO Iscan VP50).

There are other displays that, when fed 1080i60, display it as 1080p60, which has judder.

Is he downplaying 1080p? I don't read it like that...

Keep film at 24fps. Faster just doesn't look at film anymore.

PS This is just as bad as asking for no black bars, be ashamed, be very ashamed.

Is the cinema experience really 24fps? Or is it 72fps?

How many frames per second can the human eye see? (http://www.100fps.com/how_many_frames_can_humans_see.htm)

You have a fluid film with 24 fps. The film roll has to roll thru the projector. To not see it rolling you have to make the picture black while the film rolls on. You would have to blacken the screen 24 times per second. But 24 black moments are too visible. Thus you have smooth motions but flicker. The solution is: Show each frame 3 times and make the screen black 3 times per frame. This makes the black moments shorter and more frequent: "Triple the refresh rate". So you see about 72fps in the cinema, where 3 consecutive frames are the same. Strange solution? Solution of an analog world. And an example how "Brightness eats darkness".

Is he downplaying 1080p? I don't read it like that...

Come again? He's saying, "There is no discernable difference on a player that outputs 1080i vs 1080p to a 1080P display." That is, on a 1080p display you can't tell 1080i from 1080p. And if you can't tell the two apart, 1080p doesn't matter.

If you read that otherwise, please explain.

Come again? He's saying, "There is no discernable difference on a player that outputs 1080i vs 1080p to a 1080P display." That is, on a 1080p display you can't tell 1080i from 1080p. And if you can't tell the two apart, 1080p doesn't matter.

If you read that otherwise, please explain.


from your post he said:

Q.: What is your take on the different resolutions?

<kevincol> All HD DVD movies titles are encoded at 1080P/24FPS. Obviously 1080 has twice the pixels of 720, so the picture on a 1080P display will look better. In regards to 080i vs 1080p output, since all HD DVD movie titles are encode at 1080P/24FPS. There is no discernable difference on a player that outputs 1080i vs 1080p to a 1080P display. This is best illustrated on the HD DVD Mobile Experience were we have the Marantz 1080P PJ using the first Gen TSB HD DVD player at 1080i. I also added in a DVDO VP50 to output 48FPS to the Marantz. Ron, I beleive, saw this on the HD DVD mobile experience when it was in Seattle. I am a very picky HT enthusiast and the picture in the HD DVD mobile experience is the best I have seen anywhere.

1. all hd dvd movies are encoded as 1080p/24fps;
2. b/c of 1, there is no discernable difference on a player that outputs 1080i TO a 1080p display;
3. the 1080p display is recreating the 1080p from the 1080i output of the player.

so he didn't say 1080p doesn't matter but instead said that the source is encoded as 1080p and when the player outputs AS 1080i TO a 1080p display, the 1080p display recreates the 1080p source such that there is no discernible difference...

granted, this assumes a display that properly takes the 1080i out, uses the metadata, and recreates the 1080p source faithfully.

<snip>...so he didn't say 1080p doesn't matter but instead said that the source is encoded as 1080p and when the player outputs AS 1080i TO a 1080p display, the 1080p display recreates the 1080p source such that there is no discernible difference...

granted, this assumes a display that properly takes the 1080i out, uses the metadata, and recreates the 1080p source faithfully.As far as I understand, there is no metadata available to the Display. The Display will have to analyze the frames to properly de-interlace. If frames sequence is not correctly detected, your final progressive frame construction will be screwed up (Cadence detection?). IOW, you may end up combining fields of different frames (which I am referring to as motion artifacts; pardon the wrong terminology).

The only help the progressive encoding provides in this case is that if de-interlacing is done perfectly, there will be no (motion) artifacts. But to do perfect de-interlacing is not easy. Not everyone uses standalone video processors. Of course, the more expensive standalone video processors may (have to) do even pixel level analysis for proper detection and de-interlacing (bad edits, for example).

IMO, detection is the key. Decoder inside the player has that info. Once the decoder produces the output, that information is gone, as far as I understand -- after that, you are in the same bought as DVD. As far as I remember, DVD allows progressive encoding similar to HD-DVD (progressive encode with flags to aid 60i generation) -- someone correct me if my memory is failing me.

Bottomline: If encoding is 24p, best chance of getting perfect 24p is not to go through interlacing stage at all.

Bottomline: If encoding is 24p, best chance of getting perfect 24p is not to go through interlacing stage at all.I agree that this seems to be the safest. Both to avoid the Chroma Upsampling Error that the HD-A1 and some other players have, and to reduce deinterlacing issues, like some of the moire on MI:3 that was reportedly because of certain deinterlacers not adjusting fast enough. In a perfect world it shouldn't matter, but I would prefer straight 1080p24 without ever going interlaced.

--Darin

As far as I understand, there is no metadata available to the Display. The Display will have to analyze the frames to properly de-interlace. If frames sequence is not correctly detected, your final progressive frame construction will be screwed up (Cadence detection?). IOW, you may end up combining fields of different frames (which I am referring to as motion artifacts; pardon the wrong terminology).

The only help the progressive encoding provides in this case is that if de-interlacing is done perfectly, there will be no (motion) artifacts. But to do perfect de-interlacing is not easy. Not everyone uses standalone video processors. Of course, the more expensive standalone video processors may (have to) do even pixel level analysis for proper detection and de-interlacing (bad edits, for example).

IMO, detection is the key. Decoder inside the player has that info. Once the decoder produces the output, that information is gone, as far as I understand -- after that, you are in the same bought as DVD. As far as I remember, DVD allows progressive encoding similar to HD-DVD (progressive encode with flags to aid 60i generation) -- someone correct me if my memory is failing me.

Bottomline: If encoding is 24p, best chance of getting perfect 24p is not to go through interlacing stage at all.

If you read some of the stuff on DVD players (progressive) they actually do have access the the MPEG flags after decoding, the problem is with DVD material the flagging is well known to be defective on many titles and relying on it can produce defective progressive output even on 24p progressive film source.

The whole sordid DVD mess is covered in detail here...

http://www.hometheaterhifi.com/volume_7_4/dvd-benchmark-part-5-progressive-10-2000.html

b2b

Is the cinema experience really 24fps? Or is it 72fps?
Actually, it's 48fps using a "bow-tie" gate which rotates once for each frame pulldown by the projector. Each frame is shown twice, or 48fps.

If you read some of the stuff on DVD players (progressive) they actually do have access the the MPEG flags after decoding, the problem is with DVD material the flagging is well known to be defective on many titles and relying on it can produce defective progressive output even on 24p progressive film source.

The whole sordid DVD mess is covered in detail here...

http://www.hometheaterhifi.com/volume_7_4/dvd-benchmark-part-5-progressive-10-2000.html

b2bI agree about the DVD flags being broken; especially the flag indicating progressive frame.

Thanks for the link! I remember reading that. Memory is fading! That's an excellent site.


About availability of the flags: I think, for that the decoder's 60i output -> 60p output generation (or one step 60p generation) are very closely tied (same chip) for the flags to be used. My first progressive player was Denon 2800, and it used Silicon Image's deinterlacing chip which I believe worked on frame analysis since flags wouldn't be available. I am reading that site again. I will report if this is not true (flags availability).


By the way, I now found the term for what I was calling motion artifact -- it is called "combing"! Thanks to that site!

don't know if this has been mentioned already but i went to a theater recently and noticed in the film-----stutter/judder during pan scenes.

so if film being run at 24fps contains stuttering how does having 1080p24 eliminate it?

don't know if this has been mentioned already but i went to a theater recently and noticed in the film-----stutter/judder during pan scenes.

so if film being run at 24fps contains stuttering how does having 1080p24 eliminate it?

It does not eliminate the stutter inherent in film. But it does eliminate the added stuttering of 1080p60.

But displaying a 24fps source material at 60fps requires 'projecting' frame A three times, then frame B twice, then frame C three times, then frame D twice... That is particularly obvious during pans, that look choppy.

I'm amazed nobody has mentioned this already, but relatively cheap Pioneer plasmas already do a grand job of deinterlacing when fed a 1080i signal sourced from fim material by adjusting to 72Hz for a 'perfect' reconstruction in Adv mode of the 1080p24 signal, by checking the film flags. This is without any expensive intermediate processing box...

http://www.ultimateavmag.com/flatpaneldisplays/306pioneer/

Of course, Collins's findings are skewed by the fact that he was using top-notch 1080i deinterlacing during his tests (Marantz VP11S1 with Gennum VXP Video processing onboard and DVDO Iscan VP50).

There are other displays that, when fed 1080i60, display it as 1080p60, which has judder.

And those that do bob-deinterlacing on the 1080i and display upconverted (1080-delta)p/60.

And apparently from another thread actual amplify the judder somehow (more visible compared to 1080p/60 output from a player, which has locked in the judder).

These displays are a mess. How is the consumer to know what to buy?!

Gary

Little bit off topic, but at CES, Meridian booth was demoing their new "judder free" technology which interpolates 2 frames from 24p content and shows it as "true" 72p (every 72 frame are different, instead of displaying same picture 3 times). Although the technology was not perfect and sometimes showed stuttering or mis-interpolated picture, the movement was so "smooth", unlike 24p native one. Since it was very smooth, I felt it looked like live video feed, not like watching movie :)

Wow VERY cool. That is going to cost ... well ... Meridian prices. :)

If my memory is correct, they said it would be $27K or something like that :)

And those that do bob-deinterlacing on the 1080i and display upconverted (1080-delta)p/60.

And apparently from another thread actual amplify the judder somehow (more visible compared to 1080p/60 output from a player, which has locked in the judder).

These displays are a mess. How is the consumer to know what to buy?!

Gary

That's because 1080i60-1080p24 is more challenging than 1080p60-1080p24.

From cine4home's excellent special (http://www.cine4home.de/knowhow/HD24p/HD24p.htm) on the topic:

*************

A. Deinterlacing of 1080i/60Hz signals

When fed 60Hz, the video processor must fulfill two tasks: not only must it combine two matching half-images into a full image, but it also must discard the superfluous half-image.

http://www.cine4home.de/knowhow/HD24p/Pic10.jpg
Correct 1080i/60Hz deinterlacing: in each case two matching half-images are combined into a frame, and surplus half-images “are deleted”.

This task is not so simple as it seems: the scaler must accomplish an image analysis in real time (60 times per second), find the correct cadence and decide which pictures to combine or discard. It has only about 16ms per frame to do that. Therefore, it is particularly difficult to keep exact timings. Even minimum deviations cause picture stutter. Additionally when the wrong picture is cut out, the picture flow is perceivably affected. The transformation of 1080/60i into 1080/24p is one of the most challenging tasks that a scaler has to fulfill at present (it is a little simpler with fed 1080p/60Hz signals).

Test of 1080i60 processing with the VP50

They started with the 24Hz output. The processor recognizes film material in fractions of a second and accomplishes an adequate deinterlacing. At the same time it converts the signal into 24Hz, reliably eliminating the stutter. It is a great satisfaction to admire HDTV in full quality on the projection screen without artifacts. Anyone who gets used to the smoothness of the 24Hz display will find the 60Hz stutter increasingly objectionable. But every rose has its thorn: during our tests we found from time to time that the scaler lost track of the cadence and the result was a distracting stutter. This can be solved by pausing the picture: the scaler resynchronizes and the picture runs smoothly once again. However, it is annoying to have to pause the film. Other weaknesses appeared with fast picture changes, particularly with flashes, e.g. with thunderstorm scenes, occasionally a frame was skipped, which results in a short stutter. They switched over to 48Hz. Here the picture keeps cadence more stably, but there were also instances of stutters which could only be corrected by pausing the image.




B. Reverse Pulldown for 1080/60p

If one already feeds the scaler with progressive picture material, then the task is made easier for it. It is no longer necessary to decide which half-images are redundant and which half-images result in a cinema picture. The task is limited to discarding surplus frames. Since with 1080p material after 3:2 pulldown every other picture is presented twice, and every other picture three times, the task is easier. The scaler must recognize “only” each image recreated and discard all double pictures.

http://www.cine4home.de/knowhow/HD24p/Pic11.jpg
Reverse Pulldown for progressive Filmmaterial: all recreated pictures are deleted

The 24 original pictures, without disturbing stutters, maintain the native cinema frame rate. The pictures are passed on after 1080/24p at 24Hz to the projector/plasma.

Test of 1080p60 processing with the VP50

In order to examine the performance with 1080p material, cine4home switched to the Samsung BD-P1000, which has its own Faroudja processor for the 1080p output. (The European version of the Toshiba XE1 is not yet available.) The VP50 shows an impressive performance with 1080p: there aren't any isolated stutters, not even with very fast camera cuts or flashes – the picture runs as smooth as in the cinema. Additionally syncs losses are now a rarity - on average it occurred only once per film, sometimes never throughout a film.

Note: they couldn't test native 1080p24 because neither the Sony nor the Pioneer BD players are out in Europe yet.

***********

So, even using a top-notch, $3,000 video processing to extract a 24p signal, 1080i60 showed more problems than 1080p60.

Anybody can show demos where things are 60i for awhile and it still looks good. But a pure 24p chain all the way through is still better, and can deal better with scaling, PIP, overlays, etc. It doesn't rely on best case processing by everybody at each step.

- Tom

Also, I don't know about HDMI but on component outputs you are always scaling the chroma as you go from 4:2:0 as encoded to 4:4:4 full resolution chroma. It seems fairly certain to me that can't be done with full chroma resolution if you are still processing an interlaced picture. I can see no easy way a video processor could get back that vertical chroma resolution without possible artifacts.

But maybe I have not had enough coffee yet this morning and someone can point out what I'm missing.

- Tom

If he's worried about 1080p/24 then he should be more interested in Blu-Ray and shake off his Microsoft masters! Blu-Ray allows true progressive encoding for 24 fps sources, HD-DVD does not. This according to the specs. and also the recent announcement by the company that did the CHRONOS discs.

That's because 1080i60-1080p24 is more challenging than 1080p60-1080p24.
They're about the same difficulty in theory- it's a matter of correlating the images to find when they match, and comparing that to the predicted 3:2 pattern. The hard part of doing inverse telecine well is how it deals with cadence breaks, which is a non-issue here since the way VC-1 is encoded on HD DVD doesn't allow for the possibility of cadence breaks.

However, in practice, lots of displays look for inverse telecine with 60i, but don't with 60p, since there haven't been sources with 1080p24-in-1080p60 until recently. E.g., the Sony Pearl.

Test of 1080i60 processing with the VP50

But every rose has its thorn: during our tests we found from time to time that the scaler lost track of the cadence and the result was a distracting stutter. This can be solved by pausing the picture: the scaler resynchronizes and the picture runs smoothly once again. However, it is annoying to have to pause the film. Other weaknesses appeared with fast picture changes, particularly with flashes, e.g. with thunderstorm scenes, occasionally a frame was skipped, which results in a short stutter. They switched over to 48Hz. Here the picture keeps cadence more stably, but there were also instances of stutters which could only be corrected by pausing the image.

.

It sounds to me like the 48hz implementation on the VP50 isn't very good. I've been doing 48Hz for over 5 years and haven't had any such problems. What you need is something that maintains the correct 2:2 sequence, DScaler and The Rock had Judder Terminator and the Lumagen has a genlock option that works equally well. I agree it's hard to do but there are solutions out there that work.

So, even using a top-notch, $3,000 video processing to extract a 24p signal, 1080i60 showed more problems than 1080p60.

Thanks. Excellent post.

But, how many sets do 1080p/60 -> 1080p/24 conversion?

From reading other threads, there seem to be people seeing more judder with 1080i than 1080p, despite perhaps both going to 1080p/60 in the set (?). Is that possible?

Or could this be 1080p/60 v. a bad 1080i/60 -> 1080p/24?

Gary

He should ask for his money back and buy a Lumagen that works and is cheaper.

If he's worried about 1080p/24 then he should be more interested in Blu-Ray and shake off his Microsoft masters! Blu-Ray allows true progressive encoding for 24 fps sources, HD-DVD does not. This according to the specs. and also the recent announcement by the company that did the CHRONOS discs.


*sigh*

Little bit off topic, but at CES, Meridian booth was demoing their new "judder free" technology which interpolates 2 frames from 24p content and shows it as "true" 72p (every 72 frame are different, instead of displaying same picture 3 times). Although the technology was not perfect and sometimes showed stuttering or mis-interpolated picture, the movement was so "smooth", unlike 24p native one. Since it was very smooth, I felt it looked like live video feed, not like watching movie :)

Motion estimation really sucks for 24fps content in my opinion.

It absolutely ruins the look-n-feel of a movie, I want film to look like film, not to look like video.

24p judder has never worried me, yet lots of companies are working in this area.

Dennis.

I want them to just start shooting movies at 60p and be done with it.

- Tom

I want them to just start shooting movies at 60p and be done with it.

- Tom


i agree...i want 20th century movies to look like real life, not like 24fps film...jmo

Ok, since nobody will stick up for 24 fps cinema, I will. :p There are some displays today that can emulate the effect of 60 fps film by doing motion detection and generating additional frames via interpolation. Some examples include higher-end Philips TV sets with "Pixel Plus" feature and Panasonics with "Acuity". It may just be a matter of viewing habits, but subjectively I find it looks absolutely horrible with film content. It makes "Gone with the Wind" look like a soap opera shot on video. :eek: ;)

I am also not convinced that 24p output from the player is really the best option, since a good display should be able to regenerate the 24p picture from 60i or 60p without loss anyway. On the other hand, 24p output at the player would make it difficult to deal with real interlaced video material, such as bonus features, documentaries, or concert recordings shot on video. So, I believe the best way to go is to do inverse telecine in the display.

Ok, since nobody will stick up for 24 fps cinema, I will. :p There are some displays today that can emulate the effect of 60 fps film by doing motion detection and generating additional frames via interpolation. Some examples include higher-end Philips TV sets with "Pixel Plus" feature and Panasonics with "Acuity". It may just be a matter of viewing habits, but subjectively I find it looks absolutely horrible with film content. It makes "Gone with the Wind" look like a soap opera shot on video. :eek: ;)

I agree. Pixel Plus was an abomination.

I am also not convinced that 24p output from the player is really the best option, since a good display should be able to regenerate the 24p picture from 60i or 60p without loss anyway.

Should? Sure. Does? Not by a long shot. Consider what is now the hottest item on the hidef projector forum: the JVC HD1, a 1080p D-ILA projector with Gennum VXP processing (and, incidentally, amirm's next personal main display unit ;) ).

This is the situation of the HD1 and 1080i/1080p60/1080p24:



- 1080p24 is accepted, frame doubled to 1080p48 and displayed using 96Hz processing at the D-ILA panel.

- 1080i60 and 1080p60 are accepted and displayed using 120Hz processing at the panel.

- 1080p48 is not in the EDID table.

- Currently, 60i --> 24p processing for the removal of 3:2 cadence judder has not been implemented. I got the impression we wouldn't get this for the HD1. More of an HD2 feature.


So 1080p24 is obviously the way to go.

On the other hand, 24p output at the player would make it difficult to deal with real interlaced video material, such as bonus features, documentaries, or concert recordings shot on video. So, I believe the best way to go is to do inverse telecine in the display.

Well the Sony and Pioneer players support direct 24p and I haven't read of any problems with interlaced video materials.

And at any rate, I don't believe in the bonus materials compromising the main feature.

Should? Sure. Does? Not by a long shot. Consider what is now the hottest item on the hidef projector forum: the JVC HD1, a 1080p D-ILA projector with Gennum VXP processing (and, incidentally, amirm's next personal main display unit ;) ).

This is the situation of the HD1 and 1080i/1080p60/1080p24:I'm not sure what the capabilities of a single projector are supposed to prove. The main problem with current deinterlacers is that they might fall out of sync when there are breaks in the 3-2 cadence. However, with HD-DVD/BD, the 3-2 cadence is player-generated and never breaks during playback. In other words, a deinterlacer has an easy job with HD-DVD/BD players. And once you have proper deinterlacing, reversing the pulldown is quite easy.

So 1080p24 is obviously the way to go.That is only obvious as long as you limit yourself to 24 fps film material. It is not possible to display e.g. 60i video material over a 24p output, so every time 60i content appears, you'd have to switch and resync the whole display chain.

Well the Sony and Pioneer players support direct 24p and I haven't read of any problems with interlaced video materials.Has this even been tested by anyone? As far as I know, there is very little (or no?) interlaced material available on BD, and, as we all know, due to the lack of BD-J support there is also no BD yet that offers mixed 24p/60i using PiP.

It sounds to me like the 48hz implementation on the VP50 isn't very good.

The VP50 had a firmware update that improved its 48hz frame rate conversion. I watch all of my HD DVDs and Blu-rays at 48hz through the VP50 and haven't seen any judder with the current firmware.

If he's worried about 1080p/24 then he should be more interested in Blu-Ray and shake off his Microsoft masters! Blu-Ray allows true progressive encoding for 24 fps sources, HD-DVD does not. This according to the specs. and also the recent announcement by the company that did the CHRONOS discs.

Dan, you are intepreting that post incorrectly.

I am also not convinced that 24p output from the player is really the best option, since a good display should be able to regenerate the 24p picture from 60i or 60p without loss anyway. On the other hand, 24p output at the player would make it difficult to deal with real interlaced video material, such as bonus features, documentaries, or concert recordings shot on video. So, I believe the best way to go is to do inverse telecine in the display.
Sorry, but disagree with this. The player should output native resolution of the source. That is, 24p material should be output at 24p; 60i material at 60i/p, etc. Only inconvenience would be the display to resync to different rates when such switch happens.

<snip>As far as I know, there is very little (or no?) interlaced material available on BD, and, as we all know, due to the lack of BD-J support there is also no BD yet that offers mixed 24p/60i using PiP.Blu-ray spec mandates secondary video to have same frame rate as primary video. For 24p film, PiP material will have to be 24p. This is not a problem for BD.

Update:

The Toshiba XA2 won't get an upgrade enabling 24p output until next summer at the earliest.

See here (http://www.avsforum.com/avs-vb/showthread.php?p=9787972&&#post9787972).

Does anyone know for sure whether any Blu-Ray or HD-DVD player that outputs 1080p/24has no menus, PIP, overlays and titles, and therefore might be actually passing through the 1080p/24 source material from the DVD directly to the output without going through the intermediate step of processing to 1080i/60, adding the menu's, PIP, overlays and titles and then converting back to 1080p/24 for output?

Of course many would question why the player would go through that step and the reason is that it has to in order to add the menus, etc. A native stream coming out of the player at 1080p/24 with no menus, etc is likely not double-processed, but do any do that? Will the HD-XA2 (which has more rumours flying around it than Britney Spears these days) if it comes out with 1080p/24 have two 1080p/24 output modes - one sending out a raw 1080p/24 data stream with no menus, etc (you just watch 'the film') and therefore no double processing and another 1080p/24 mode that includes the menus, etc and hence involves double processing? Or is there only the first 1080p/24 output mode and you have to forgo the menus, etc?

Everyone assumes (or is hoping) that any player that now outputs 1080p/24 with menus, etc. or will in the future won't do this double conversion, but there is no proof that they don't or won't. And just because a player outputs 1080p/24 that is not proof that there is no double conversion before the stream is output..

Does anyone know what is really going on behind the scenes? no pun intended ;)

Updates:

Toshiba XA2/XE1
A Microsoft representative confirmed (http://www.worldinhd.com/movabletype/archives/2007/05/planning_des_ma_1.html#more) that the firmware enabling 24p output for the Toshiba XA2/XE1 will come by the end of September.

PlayStation 3
Firmware 1.80, just released, enables 24p output:

http://www.bellapix.com/user/global/ACCOUNTS/USER4193ebf97eafd/images/dsc00333.jpg

Forum member Li On (a veteran on the projector forums) has tested it and says:

24p output works correctly for all 3 video codecs MPEG2, VC1 and AVC! Millions of blu-ray players have perfect 24p Output overnight! :D

For me, the PS3 getting 1080p24 means that it has hit the mainstream as a feature for HD players.

More displays will start to have this feature and it will become a standard.

Living in the UK, I've watched PAL material all my life. I was dreading a HD future where 3:2 pulldown judder was unavoidable. To my PAL trained eyes I can pick up the judder instantly.

Of course the PAL speed-up was less than ideal.

Now we can have films displayed with very few compromises.

I'm just saving my pennies to buy one of those new Pioneer panels with 1080p24 capability.

I think we in PAL land is very happy for 1080/24P.

So, has anybody actually had an opportunity to try the 24p output yet? Unfortunately I can't, because I currently don't have access to a 24p display. How does it handle menu overlays etc.? Is the judder completely gone?

There was a short piece on the german Heise news site about the PS3 update:

http://www.heise.de/newsticker/meldung/90182

Regarding the judder, it says (crude translation by me):

"Using the 3-2 pulldown, the enjoyment of the film is sometimes disturbed by irregular judders on slow horizontal camera pans. However, in our test the judder does not go away with 24p output, it just looks different, more even. But it also depends strongly on the film material and the video processing chips in the display how large the difference will be."

I really hope this was just their display. Can anybody confirm?

I was aware that the first BD player did 1080p/24 to 1080i/60 to 1080p/60 2 step conversion. But how about the Toshiba HD-A20 that outputs 1080p/60? Does it just perform 3:2 pulldown on the 1080p/24 source?

Regarding the judder, it says (crude translation by me):

"Using the 3-2 pulldown, the enjoyment of the film is sometimes disturbed by irregular judders on slow horizontal camera pans. However, in our test the judder does not go away with 24p output, it just looks different, more even. But it also depends strongly on the film material and the video processing chips in the display how large the difference will be."

I really hope this was just their display. Can anybody confirm?

24fps film has inherent judder due to the slow frame rate. It will be reduced compared to the same material with 3:2 pulldown, but it's never going away.

24P is just too slow for moving video though we are used to it. But it will appear jerky on slow pans. However if the display frame rate is not a multiple of 24 then there will also be judder, the 3-2 irregular motion timing that appears when the display frame rate doesn't match a multiple of the source rate.

- Tom

ohh good... Now I have to spend a few thousand on a 1080p/24 HDTV

I'll stick with my 720p/1080i set for a little while longer.

I tried the new PS3 firmware, with 24fps output, on my RS-1 last night. As someone else mentioned, because 24fps is a little slow, there is still the smallest amount of judder. However, it is MUCH, MUCH better than 3:2. I was switching back and forth on the scrolling credits at the end, and 24 was nearly perfect. Switching back to 60 and doing a direct comparison was painful. Switching back and forth made the old judder unbearable. FYI, the RS-1 doubles the Hz and displays 24fps at 48Hz. I'm very happy, and my HD-DVD player is going to collect even more dust now.

24fps film has inherent judder due to the slow frame rate.No it doesn't.

While film may exibit a strobing effect on fast pans or objects like rotating wagon wheel spokes, this is not considered judder!

Judder is a unique byproduct of converting film's 24 FPS frame rate to be displayed at video's 30 FPS (or multiple therof) frame rate. It has a very different look from the normal strobing displayed on 24 FPS sources displayed at 24 FPS or multiples of the 24 FPS frame rate.

Vern

"Strobing", "judder"...this is all a semantics game at this point. The fact remains is the end result at 24 fps is not smooth motion, when motion is depicted. I think the point of the statement you quoted was that you can remove all other sources of judder from this medium, but ultimately, you still have to deal with the inherent judder of 24 fps. There is no way around this (aside from some tricky digital processing, that is decidedly undesireable from the purist standpoint), other than framerate "reform" on the infrastructure of film as a medium.

"Strobing", "judder"...this is all a semantics game at this point. The fact remains is the end result at 24 fps is not smooth motion, when motion is depicted. I think the point of the statement you quoted was that you can remove all other sources of judder from this medium, but ultimately, you still have to deal with the inherent judder of 24 fps. There is no way around this (aside from some tricky digital processing, that is decidedly undesireable from the purist standpoint), other than framerate "reform" on the infrastructure of film as a medium.



They are indeed 2 different issues, but both produce noticable obstacles to perceiving fluid motion.

I think it's usesful to qualify them as"framerate judder" or "3:2 cadence judder".

Yes, I am aware of their difference. The point I was making is that as far as the end result is concerned, smooth motion will remain elusive regardless of if you classify or not as "judder" or even call it a different kind of judder.

The point I was making is that as far as the end result is concerned, smooth motion will remain elusive regardless of if you classify or not as "judder" or even call it a different kind of judder.

While that may be technically accurate, the inherent limitations of the motion picture film frame rate should not be used to diminish the desirability of removing yet another of video's limitations from the presentation of film on video.

Yes, I am aware of their difference. The point I was making is that as far as the end result is concerned, smooth motion will remain elusive regardless of if you classify or not as "judder" or even call it a different kind of judder.

Indeed. But 24p (judder and all) is what the film is.

The addition of 3:2 cadence is an unfortunate side effect of displaying on devices clocked with 60Hz framerates. It also happens to be an "uneven" judder, as the time-interval varies between 2 and 3 frames. This makes it even more objectionable to the eye.

So while I agree that 24p will never be "smooth", 24p along with 3:2 judder is even "unsmoother", to use my own made-up word.

We are in agreement then.

group hug :)

But I also agree.

- Tom

Here's to 48 fps for film!!!!

(not holding breath... :( )

Here's to 48 fps for film!!!!

(not holding breath... :( )

Wouldn't that be nice!

(also not holding breath.....)

Here's to 48 fps for film!!!!

(not holding breath... :( )

Not before 10 years. I long it took from the first spec on HD to finally get it for real in out living room. :eek:

Why the Xbox 360 HD DVD cannot update the firmware too? I'd love to see 24hz HD DVDs using the 1080p24 feature of my Mitsubishi HC5000... :confused:

Ron (dr1394) has just posted (http://www.avsforum.com/avs-vb/showthread.php?p=10852728&&#post10852728) some very useful information, which I'll try to summarize here. For the details, go to that post.

HD DVD VC-1 bitstream: In the sequence header, INTERLACE=1 and the frame rate is 30 * 1000/1001 or 29.97; in frame headers, TFF (top field first) and RFF (repeat first field) vary in each frame.

Blu-ray VC-1 bitstream: In the sequence header, INTERLACE=0 and the frame rate is 24 * 1000/1001 or 23.976; in frame headers, RPTFRM is always 0.

His summation:


The bottom line here (and why it's taking so long) is that the HD-DVD specification has to be changed to support 24p output. There needs to be another flag that says the decoder can safely ignore the RFF and TFF flags. This new flag indicates that the 29.97 fps bitstream has perfect repeat field cadence, and is really a 23.976 fps progressive sequence of frames.

Without the flag, the player doesn't know what's really in the bitstream. It could be a straight 29.97 interlaced stream (which will look terrible if played with 24p output), or it could be a stream with imperfect repeat field cadence (which will be herky jerky at the cadence breaks).

Ron

Obviously, they will be unable to change the header coding on the discs, so will they be simply ignoring the header data in order to get to the 1080p24 encode? Or did I miss something and these discs aren't encoded at 1080p24 at all?

Any thoughts on the long term from the film side here? As things move digital, from recording to theater display to delivery, it seems that a move to 30fps is natural. It will slightly improve motion quality in pictures, and natively transition to consumer and broadcast formats, which are naturally on a 30 fps interval (1080i 30fps, 1080p 30fpsx2). Rather than try and modify equipment that naturally wants to run at 60Hz, why not just get filmmaking out of the last century? Any film guys here with inside thoughts on how the digitalization process is influencing any of this?

Great info from Ron! That means HD-DVD encoding is the same as DVD. The image frame is stored in 2 fields with repeat flag to tell the decoder for a 60i output. In a perfect encoding of a 24p source with a perfect repeat flag sequence, the decoder can simply read the flag and know exactly which 2 fields to combin for the original 24p image. But the repeat flag is usually NOT 100% correct throughout the whole movie (blame the encoder or whatever) so there may be some motion judder or combing with the simple flag reading process. And in quite a few cases (as seen in DVD transfer), the repeat flag is mostly or completely wrong and a flag reading decoding will give awful deinterlacing artifacts.

And the player can't simply "ignore" the flag, otherwise it can't tell between a 24p encoded or a real 60i content. It can add a user manual switch output mode but that will be a far cry from the blu-ray sure work processing.

The other solution is to use a REAL HD deinterlacing chip in the player to actually analysis the video content and resturct a 24p output, like those new generation video processing with HQV or VXP chip. But then the cost will be much higher and there maybe other processing bug to workaround on those deinterlacers.

regards,

Li On

Great info from Ron! That means HD-DVD encoding is the same as DVD. The image frame is stored in 2 fields with repeat flag to tell the decoder for a 60i output. In a perfect encoding of a 24p source with a perfect repeat flag sequence, the decoder can simply read the flag and know exactly which 2 fields to combin for the original 24p image. But the repeat flag is usually NOT 100% correct throughout the whole movie (blame the encoder or whatever) so there may be some motion judder or combing with the simple flag reading process. And in quite a few cases (as seen in DVD transfer), the repeat flag is mostly or completely wrong and a flag reading decoding will give awful deinterlacing artifacts.

Here was Amir's explanation:

http://www.avsforum.com/avs-vb/showthread.php?p=10801182&&#post10801182

The source for DVD is usually a 480i tape. As such, what is being fed to the MEPG-2 encoder is 60i interlaced "video." The MPEG-2 encoder in real-time analyzes the source field by field, to determine if is progressive or not. Now, this test has to be "conservative" in that you don't want to throw out interlace fields by mistake as otherwise, the artifacts will be nasty. So the encoder errs on the side of flagging things that are in doubt as interlace. Result is that what is output, even for “movie” content, has mixed set of flags, indicating both progressive and interlace frames/fields. This makes the job of the processor in the player much more difficult as it can’t trust the flags to be correct (hence the reason good video processors such as HQV, DVDO, etc. ignore these flags and do their own image analysis to determine if the source is progressive or not).

Before anyone says the above is a corner case and doesn’t happen in reality, let me give you some examples. Since it was Paid who claimed DVD is progressive, why don’t we pick one of the movies out of his shop, encoded with their Sony MPEG-2 encoder. I happen to have files with complete flag list of the frames in movies The Fifth Element, Spiderman, an MIB 2. If you look in there, you see a ton of fields flagged as interlaced. TFE for example, starts completely in interlace mode! It then switches to progressive but at chapter points, jumps back to interlace. It also does this at other points in the movie. So if a reference quality title like this has mixed flag, not much hope is left for others which are not.

Now, HD DVD is a completely different animal. Here, we are being fed 24p material, not 60i. The encoder gets told the frame rate is 24p and it encodes at precisely that rate. As such, it will not perform any image analysis to determine interlace or progressive. As the movie is being encoded, the stream is flagged as being progressive with this additional metadata. These flags are guaranteed to be correct by definition since the encoder is locked into progressive 24p mode and never changes randomly as it does with DVD. So a decoder can easily trust them to produce proper 24p output.

Now you see why I was surprised when Paid made that statement. There is flagged encoding, and then there is proper flagged encoding. In some sense, HD DVD encoding is BD encoding with additional metadata for conversion to interlace. The two are much closer to each other than DVD is to either one of them.

I don't have time to see if this has already been answered but if the topic assertion is true: does it depend on the display and seating distance?

For example, I can clearly see from my own detailed personal tests that there is absolutley no discernable difference between 1080p and 720p from where I sit given the size of my display.

Would such a scenario also apply here? If I can't tell the difference between 1080p and 720p from where I sit then I shouldn't be concerned about "native, judder-free 1080p24" then, right? Or wrong?

Isn't judder-free p24 an oxymoron? :p (Yes, I agree p24 support on LCD's would be a good thing, but not the end all fix to addressing poor frame rate.)
No, it's redundant. :p

Why not ask Amir in the Insiders thread? I posted a link to Ron's post in response to someone else's post over there but it didn't get much activity. It does seem there are opposing facts about this.

The problem here is one of semantics. It all depends on what you mean by the word "encoded".

If by "encoded", you mean the bitstream syntax, then DVD and HD-DVD are encoded in the same way. Both encode 24 fps film content into a 29.97 fps bitstream with telecine flags (repeat_first_field and top_field_first).

If by "encoded", you mean the physical process of taking a master, plugging it in to an encoder and creating a bitstream, then DVD and HD-DVD are different. This is because there is no 24p tape or interface standard for SD content. All content is telecined to 60i and fed to an encoder at 60i. The encoder must do it's own inverse telecine to create the flags (repeat_first_field and top_field_first) present in the bitstream.

HD has the luxury of having both a 24p tape format and 24p interface standard. You can feed the encoder 24p and create a 24p bitstream (with can be used directly on Blu-ray). For HD-DVD, you must take that 24p bitstream and modify it to be a 29.97 fps bitstream with telecine flags. Since the modification is done after the fact, it's simple to have perfect flag cadence. You just start the cadence on frame 1 and continue until the end of the movie.

So there's no "opposing facts" here. Both Amir and I are correct, but you have to consider our comments in the correct context.

Ron

Ron, thanks for the clarify. So the HD-DVD disc encoding encodes in the same way as DVD in 60i with repeat flag, though the master maybe in 24p and the encoder *should* generate a PERFECT pulldown sequence for a 60i disc encoding. Hence the decoder can (may) savely ignore the repeat flag and simply combin the correct fields for a 24p output.

I see 2 questions:
- how can we be SURE the HD-DVD master is indeed a real 24p source, AND the encoder does indeed encodes with PERFECT repeat flag? As we couldn't tell from the encodes on a HD-DVD. Should we simply believe them?
- if the situation is that simple, why there is still no 24p output option on a HD-DVD player?

On the other hand, the quote some the insider also emphasis blu-ray does NOT encodes in 24p which is completely false according to your analysis. Could you please clarify on the subject too? Thanks in advance.

regards,

Li On

The problem here is one of semantics. It all depends on what you mean by the word "encoded".

If by "encoded", you mean the bitstream syntax, then DVD and HD-DVD are encoded in the same way. Both encode 24 fps film content into a 29.97 fps bitstream with telecine flags (repeat_first_field and top_field_first).

If by "encoded", you mean the physical process of taking a master, plugging it in to an encoder and creating a bitstream, then DVD and HD-DVD are different. This is because there is no 24p tape or interface standard for SD content. All content is telecined to 60i and fed to an encoder at 60i. The encoder must do it's own inverse telecine to create the flags (repeat_first_field and top_field_first) present in the bitstream.

HD has the luxury of having both a 24p tape format and 24p interface standard. You can feed the encoder 24p and create a 24p bitstream (with can be used directly on Blu-ray). For HD-DVD, you must take that 24p bitstream and modify it to be a 29.97 fps bitstream with telecine flags. Since the modification is done after the fact, it's simple to have perfect flag cadence. You just start the cadence on frame 1 and continue until the end of the movie.

So there's no "opposing facts" here. Both Amir and I are correct, but you have to consider our comments in the correct context.

Ron

Therefore both BLu Ray and HD DVD store progressive frames (not interlaced fields).

It's a matter of correctly interpreting the additional metadata should one need to obtain a 60i stream (i.e. apply pullup in the player).

Not so fast! If Ron really mean HD-DVD encodes the same way as DVD, then image is stored in (pair of) field instead of a full progressive frame. The difference is in the master and the encoder (if we'd like to believe from some insider).

DVD
- master is in 60i
- encoder must analysis the 60i source and reconstruct a 24p stream, then add repeat flag for 60i output
* problem is the encoder may give incorrect repeat flag hence simply ignore the repeat flag may give mixed result on a 24p output

HD-DVD
- master is in 24p
- even though the disc encoding is still in 60i, encoder generate PERFECT repeat flag, hence simply ignore the repeat flag should give perfect 24p output

In the above 2 cases, we have no access to the master or the encoding process so we can only believe the setup. The real data on both DVD and HD-DVD are in the same format as we can verify.

For blu-ray, we could careless about the master or encoding process, as the real data on the blu-ray disc is stored in native 24p format without usage of repeat flag. The decoder should have it's own logic to output to a interlaced display.

regards,

Li On

Are the Pioneers the only plasmas that support 1080p @ 24 as of now ?

I was about to pull the trigger and get the new Samsung FP-T6374 63inch 1080p but now I"m having second thoughts after talking to Samsung level 2 tech support today and confirming no 24hz support and no firmware upgrade expected and he felt I'd have to wait till next years production models to see it :eek:

Li On

Is there any benefit/more detail to true 1080p 24 verses something encoded to disc 60i and output reconstructed as 1080p 24. Do both show the same results if done properly ?


Im with you wondering why its taking so long to give us 24 output.


Thanks!

There is currently a way to see HD DVD in 1080/24p. That is the LG combo player. The LG BH100 does 1080/24p with both Blu-ray and HD DVD.

I had the LG in my system for a weekend to play with. I ran many BD and HD DVD discs through it and found no difference between the formats other than the obvious differences between transfers. The one thing that 24p gets you, smoother motion, was evident on both HD DVD and Blu-ray. That alone tells me the data on both formats is 24p natively.

As for why Toshiba is taking so long, my guess is that they are trying to figure out the best way to make the players do something they didn't really plan for.

Robert

From day one the marketing hype from HD DVD has been 1080p 24.

When you say no difference between formats with 24 output other then picture differences are you suggesting one format is superior to the other?

24 output even if re constructed will still result in smooth pans so that does not tell us how it is being done internally. One of the BD players is reconstructing from 1080i but you would never know it. But we want true 1080p 48 right off the disc to avoid additional processing stages. Hopefully that will be what we get. Its kinda scary its taken this long so I hope it is not a sign as you mentioned it cannot be done with the current crop of players

Li On

Is there any benefit/more detail to true 1080p 24 verses something encoded to disc 60i and output reconstructed as 1080p 24. Do both show the same results if done properly ?


Im with you wondering why its taking so long to give us 24 output.


Thanks!

I'm not Li On but I'll speculate a bit. When encoding a video in interlaced format for these discs (and most purposes) the video has to be converted to a 4:2:0 format with only 1/4 the chroma resolution compared to the luma. The interpretation and means of calculating the value of those chroma pixels differs depending upon whether you specify an interlaced or progressive format. Hopefully VC-1 on HD DVD is using a progressive encoding (color conversion) here, but I don't know.

Meanwhile, you have to consider what the player is doing and who it is delivering it to. On output it has to convert the chroma format back to 4:4:4. Previous players have treated the encoded format as interlaced and may be doing this conversion in an interlaced fashion which gives lower vertical chroma resolution.

Standard deinterlacing chips may also assume interlaced 4:2:0 chroma encoding, not sure. But there are thus a lot of issues about which assumptions may be made here. If mixed material with some interlace (PIP?) is allowed here it further complicates the issue. So while it is possible to encode material progressively and just ignore the flags for 24p output the players may not be safe in aways assuming that is the correct path. And if they don't make that assumption there is the possibility of some loss of detail.

- Tom

From day one the marketing hype from HD DVD has been 1080p 24.

Actually, whatever marketing of 1080p or 1080p/24 for HD DVD was related to the software, which is all true. I don't recall any player hype from Toshiba about 1080p until the HD-XA2 was ready. While Toshiba has indicated 1080/24p was possible with the XA2, they haven't really made a big deal about it. I think they knew it was not something they had prepared for and it has only become an issue as a response to the preceived marketing advantage Blu-ray is getting from 1080/24p with their players.

When you say no difference between formats with 24 output other then picture differences are you suggesting one format is superior to the other?

No, what I'm saying is it appears the data on both HD DVD and Blu-ray are the same 1080/24p.

24 output even if re constructed will still result in smooth pans so that does not tell us how it is being done internally. One of the BD players is reconstructing from 1080i but you would never know it. But we want true 1080p 48 right off the disc to avoid additional processing stages. Hopefully that will be what we get. Its kinda scary its taken this long so I hope it is not a sign as you mentioned it cannot be done with the current crop of players.

If we cannot see any difference between a player that is outputting 24p natively and one that is reconstrucing 24 frames though processing, then does it really matter how it's being done? If it looks the same, then it is, for all practical purposes, the same.

BTW, the unofficial word is that Toshiba's solution for 1080/24p with the XA2 is for native 24p output without processing. That is what has been indicated as taking so long. Getting it "right".

BTW, the unofficial word is that Toshiba's solution for 1080/24p with the XA2 is for native 24p output without processing.

Bring it on, worth the wait :)




If we cannot see any difference between a player that is outputting 24p natively and one that is reconstrucing 24 frames though processing, then does it really matter how it's being done? If it looks the same, then it is, for all practical purposes, the same..

I was using that to point out there is no way for us laymen to really know how it is being done. Just because it is labeled to output 24 that is no guaranty its done properly. While you and I may not see a difference the technical people behind the scene such as Joe Kane do not want to see any processing and promote that stance so there must be reasons to avoid the extra steps from processing.

If I were to find out it was being processed to get to 24 then myself personally would lose all interest in owning it as a product as I think many others would feel the same.

Ether way if indeed they are talking direct then this conversation is moot other then "Bring it on" we are ready!!!

Over in the LCD Flat Panel Displays forum on AVS they have this interesting thread on 120 Hz refresh displays: http://www.avsforum.com/avs-vb/showthread.php?t=847961&page=1&pp=30

Included in the first post listing of models is the 5:5 pulldown (that lets a 24 Hz input feed work its reduced judder magic) question. Negative for the new Sharps -- unknown for all the others.

Why won't the TV vendors just tell us a yes/no answer. :(

If mixed material with some interlace (PIP?) is allowed here it further complicates the issue. So while it is possible to encode material progressively and just ignore the flags for 24p output the players may not be safe in aways assuming that is the correct path. And if they don't make that assumption there is the possibility of some loss of detail.


Thanks for the head up. I forgot the PiP (or any popup video) factor! Such feature sure won't work if one day HD-DVD do provide a 24p output. So much for the superior of "interactive" feature...

regards,

Li On

So much for the superior of "interactive" feature...

It's really easy to discount a feature when the format you have chosen to support doesn't have it. I'm certain you and the other "supporters" will be the first ones to start crowing about how much better BD-J interactivity is on Blu-ray, when someone can finally make it work.

I forgot the PiP (or any popup video) factor! Such feature sure won't work if one day HD-DVD do provide a 24p output.Huh? There are all types of engineering choices. The best to me would be to just decimate the 60i or 30p PiP video down to 24p and to heck with the PiP quality -- let it stutter. Granted that this issue is likely what is making Toshiba take so long to provide 1080p24 output on the XA2, IMHO.

I don't discount HD-DVD interactive feature. It's fine for those who like it and use it. I just hope the feature is not a negative factor for the 24p output option.

As far as let PiP "stutter" in 24p output, I don't think J6P will be happy with the "feature"! More and more display supports 24p Input and the player may work in 24p output automatically (like the PS3) but if the user bring up PiP, then all hell break lose...

And I hope when BD-J finished interactive spec will take concern of a 24p output.

regards,

Li On

I understood that for BD that PiP will be (must be?) in 24p for a 24p main feature. That would work for HD DVD also -- except so much existing source content (extras) for the PiP is in 60i format right now. I'm sure that Ben, Andy, or bkilian from MSFT can explain this better.

As far as let PiP "stutter" in 24p output, I don't think J6P will be happy with the "feature"! More and more display supports 24p Input and the player may work in 24p output automatically (like the PS3) but if the user bring up PiP, then all hell break lose...

What do you think happens now when you pull up a pop-up menu on a Blu-ray? Those menus are rendered and encoded at 60hz.

Right now, most (all?) Blu-ray players that offer 1080p24 output will switch back to 1080p60 if you pull up a menu, which forces most displays to blank out for a minute while they resynch. Clearly not an ideal design implementation.

That's one of the factors slowing Toshiba down. They'd rather convert the HDi and PiP elements to 24hz, which is complicated to implement.

What do you mean "pop-up" menu? For scene/language selection pop-up it's a static menu and works fine in 24p movie running model, at least on my PS3. If you mean the full disc menu with motion video background (or some intro video) then it won't matter.

regards,

Li On

Just tried the Sony S1 player with Underworld Evolution, pop-up menu for scene/language of course works fine in 24p output movie playing, even the main menu with the spinning video runs perfectly (smooth and correct) in 24p output!

Josh, could you mind tell us which blu-ray player you tried does not work in 24p output with pop-up menu? Thanks in advance.

regards,

Li On

Josh, could you mind tell us which blu-ray player you tried does not work in 24p output with pop-up menu? Thanks in advance.

Honestly, I can't get the 1080p24 output of my Sony S300 to sync at all with my VP50 processor, so I'll have to get back to you on that. :) I was basing my post on information in a previous thread. If it was wrong, I'll stand corrected.

Just tried the Sony S1 player with Underworld Evolution, pop-up menu for scene/language of course works fine in 24p output movie playing, even the main menu with the spinning video runs perfectly (smooth and correct) in 24p output!

Josh, could you mind tell us which blu-ray player you tried does not work in 24p output with pop-up menu? Thanks in advance.

regards,

Li On

I can confirm that the PS3 works fine outputting 24p to my projector with the in-movie pop up menu active. So I am not sure what Josh means by "most players" either since the PS3 constitutes the majority of Blu-ray players out there...

The 24 output option works great on my PS3 and S1 as well using the pop up menus.

I do think Josh could be having some trouble but I do not think it is the player. I say this because I had a projector that when I pulled up any menus it would flip out yet two other projectors were fine. I reported this to the projector manufacture who sent a new firmware update which fixed everything. I think 24 output is still new to the industry and many manufactures do not know how to handle it properly yet.

Toshiba has just announced (http://www.twice.com/article/CA6456373.html) that it will add 24p frame-rate output to its HD-XA2 and HD-A20 through an update planned in September.

Whenever we watch our PAL discs with the oppo we watch native 25fps at 50 hz. on our PJ, basically judder free (sped up by 4% though...) on some discs where I have both PAL and NTSC copies, the PAL always looks smoother that the NTSC at 60hz...

Toshiba has just announced (http://www.twice.com/article/CA6456373.html) that it will add 24p frame-rate output to its HD-XA2 and HD-A20 through an update planned in September.

It keeps getting further away, now its Sept. I wonder why it is taking so long.

It keeps getting further away, now its Sept. I wonder why it is taking so long.

Actually, this is the only official date that Toshiba has announced in the US. Toshiba in Europe annonced the September date some weeks ago, so this isn't really a delay per se.

Thanks Robert. I remember hearing June somewhere along the line. I thought that was from Robert at VC.
A few more months is not to far away. I guess it will make for some news at Cedia.