workprinters at 18fps?

[S8 Booster]

since you guys havent got a clue....;) ill fire up my old AP40 and make you some sample clips from my 1:1 25 fps prog film - any which way u like it.....

pick a choice... all? well.. ok....

[MovieStuff]

Ummm, yeah. I don´t know anyone who has spent $8000 on a livingroom TV.

But you don't have to spend $8000 to see proper display of interlaced footage on a livingroom TV.

I guess we have different perspectives about it.

Not at all. We both agree that the more you spend, the more likely it is that you will get proper display of interlaced video. However, your previous position was that it was inherently impossible to have proper display of interlaced video, regardless of price, because you felt that all flatscreens are progessive only and will deinterlace any interlaced footage and make it look progressive. That is incorrect.

They are not only different frpm the perspective of budget, the difference is also where you can find them (at least I cannot fins any broadcast monitprs in the local electronic chains. I can find lots of regular LCD TVs though, but no broadcast quality TVs).

I am talking about "normal TVs", not top-dollar-TVs or broadcast-grade stuff.
Just regular TVs. And those still somehow need to de-interlace the signal because they cannot show the fields one-by-one. How can you not understand this? :?

I understand fine. But what you consider a "living room TV" and what others might consider such aren't necessarily limited to the lowest common denominator. Still, you don't have to spend a lot of money to have good interlaced display. And the whole point of this discussion was your previous statement that using an interlaced pulldown pattern would be pointless in the future since all flatscreens will be deinterlacing the image and making it progressive. Your use of the term "deinterlacing" was incorrect because even the cheapest flatscreens do not do this and, as you yourself noted, more and more are going to true interlaced display. So the obvious trend is that interlaced displays will be around for quite a while.

Roger

[Uppsala BildTeknik]

But what you consider a "living room TV" and what others might consider such aren't necessarily limited to the lowest common denominator.

No, but that doesen´t normally include professional broadcast monitors either. ;)

I was surprised to hear that the broadcast LCDs are showing true interlaced images. Perhaps in the future all monitors are capable of this? Or perhaps they just think the image on the interlaces modes is good enough, the selling points are probably high progressive modes (like 1080p)? Only time will tell.

Still, you don't have to spend a lot of money to have good interlaced display.

Sure, but I never talked about good interlaced playback, I talked about true interlaced playback (as in one field, then the next, then the next, and so on.), I never heard of true interlaced playback on flatscreens beforre the mentioning of broadcast monitors here.

Come to hink of it, I wonder how the monitors react to a interlaced SD videofeed? The monitor has 1920x1080 pixels, so when it stretches the image to fill the screen it needs to calculate it to a higher pixelcount. Upscaling the resolution. What happends to the interlace fields, do they just get thicker? I´m guessing that would look pretty bad. Upscaling it like progressive images... wouldn´t that give a better possibility to get a good image in the higher pixelcount?

I currently feed my TV from a computer, 1080p at all times. The software in my computer de-interlaces, upscales, filters and stuff whenever needed. I can actively choose to de-interlace or not depending on the source material (film or video). It does this automatically too, but I can override it if it doesen´t choose the correct settings for some reason.

Just for fun I shut off the de-interlacing on a videorecording, and I get lines. On with the de-interlacing and it looks all good. (how it de-interlaces I don´t know exactly, nor do I know if it should be called de-interlacing or something else. But it does take away the ugly fields). I´m saying it looks all good with playback with interlaced footage, but it still isn´t true interlaced playback (heck, I am feeding the TV with 1080p).

[christoph]

No this has nothing to do with removing pulldown. If you use the DVX100a in the 30p mode, which does not require pulldown removal, it has the same lower resolution, though the documentation says that it has true progressive scan capability without interpolation. I have worked with it and several other DVX units on other projects and they all act the same.

well, as i never had a 24P DVX model in my own hands, it's hard to argue your hard facts.. all i can say is that the 25P model *has* full resolution in progressive mode (and doesnt do any fake deinterlacing)..
i can also say that i've read about very several people testing the DVX 24pA that came to the conclusion that it did indeed true progressive.

Does the new Sony V1 use CCDs or CMOS chip sets?

the V1 is CMOS as is the EX1, both of which do true progressive. but just for the record, the HVX is CCD and i have done green screen work with some HVX 30P material that was clearly progressive.

++ c.

[christoph]

I know plenty of people that spend $3000-$8000 on LCD displays for the living room that emulate interlaced display just fine. As I have repeatedly said, whether you get proper display of interlaced imagery is dependent on the budget but there is nothing that is inherent in flatscreens that prevents you from being able to view interlaced footage; only budget limitations.

well, it depends a bit on what we consider proper interlaced playback..
sure it plays smoother then a software deinterlacing on a computer monitor.
but do you get real interlacing lines?
most likely no.. (otherwise most people in the post industry would stop buying the expensive professional monitors)

let's look at a typical sony monitor, like the bravia KDL-32U2530:
it has a pixel resolution of 1366 x 768.
now we feed it a DV signal, which is 480pixels high.
how exactly should it display this interlaced, as one line of the original footage is 1.6lines high on the TV?

but all theory aside here's an easy way to test:
make a white horizontal line on black background, 2 pixels high.
encode it to an interlaced codec (ie DVD, miniDV or whatever), then play it back on the TV.
does the line look like it is only one pixel high and jumps up and down 60 times a second?

another way is to make a still from a frame that had movement. freeze the frame without changing it's pixel dimensions, encode it back to a video codec, play it back on the TV. if it's a true interlaced TV it will give you headaches because it will have interline flicker like mad.

anyway, this has gone far too way off topic and i'm actually not terribly interested in discussing consumer TVs and their image smoothing algorithms. i just thought i could shed some light on the murky grounds (which apparently i haven't ;).
++ christoph

[MovieStuff]

I know plenty of people that spend $3000-$8000 on LCD displays for the living room that emulate interlaced display just fine. As I have repeatedly said, whether you get proper display of interlaced imagery is dependent on the budget but there is nothing that is inherent in flatscreens that prevents you from being able to view interlaced footage; only budget limitations.

well, it depends a bit on what we consider proper interlaced playback.....

What I consider proper interlaced playback is anything that has the familiar, smooth motion characteristics of interlaced playback, regardless of how it is achieved. But what they don't do is make anything shot interlaced look like it was shot on a progressive scan camera. To me, that's the main thing in contention here.

Roger

[S8 Booster]

cristoph... just a curiosity question... the early versions of compressors for the mac (AP NLEs) obviously tried to take advantage of the "no moving" areas in the images . it tried to freeze or "recycle" the no motion pixels to keep the bitrate as low as possible.

is this totally eliminated with the new compressors?
or else not a lot of artifacts will appear i guess.

you should really see the "ghosting" artifacts on my 1 066,8cm plazma ;)

shoot....

[christoph]

cristoph... just a curiosity question... the early versions of compressors for the mac (AP NLEs) obviously tried to take advantage of the "no moving" areas in the images . it tried to freeze or "recycle" the no motion pixels to keep the bitrate as low as possible.

is this totally eliminated with the new compressors?
or else not a lot of artifacts will appear i guess.

i've done *a lot* of tests with different deinterlacing algorithms, from very basic field doubling, over field interpolation, field blurring to very advanced adaptive or time mapped deinterlacers (i even built one myself in shake :).. all of them have their disadvantages :/

problem is that the more sophisticated the algorithm, the bigger the danger of weird artifacts in small details. so atm, i usually use a very basic deinterlacer like field blurring for most footage and accept the softer image (HDV is too sharp anyway). i only use the high-end deinterlacers if i really need the extra resolution for post production and can manually fine tune each shot, like complicated tracking shots or green screen. but then again, if i have the choice i'll always shoot progressive for those purposes in the first place.
++ christoph

ps: i just realized that you might have been talking about video compression rather then deinterlacing algorithms..
if so, today this is a very common approach, mpeg2, mpeg4 and flash etc all do this, but all of them pretty well if you give them a decent bitrate. i hardly know any codecs in AP4 that did this though, but then again, i haven't used AP for a long time (had horrible experiences with it, although CS3 is now kinda decent)

[S8 Booster]

i guess you are right about both factors but does one eliminate the other in terms of artifacts?

pretty complex those compression regimes/alogaritms i guess.

havent looked so much into this but the AP interlace/progressive (full frame) stuff is very easy to distinguish on a computer - the full frame is very jerky compared to those interlace playback option and i guess it will "burn in" severely on a cheap TV/monitor - a lot more than interlaced framing.

possibly not completely relevant but it appears that the prog/inter frame preset in AP4 has less influence on image quality than the choice of compressors but this is really old stuff so it may be obsolete n not relevant.

shoot.....

[christoph]

What I consider proper interlaced playback is anything that has the familiar, smooth motion characteristics of interlaced playback, regardless of how it is achieved.

well, by this definition, most of todays decent consumer LCDs TV will indeed do "proper interlaced playback".

it's just that they don't really do it by actually displaying interlaced lines ;)
++ christoph

ps: just not to give the impression that this is all nitpicking..
i recently had to redo a DVD twice because i made some field order mistake which you couldnt notice on my LCD at home.. it only became apparent when i tested the finished DVD on a CRT at the university.

[MovieStuff]

What I consider proper interlaced playback is anything that has the familiar, smooth motion characteristics of interlaced playback, regardless of how it is achieved.

well, by this definition, most of todays decent consumer LCDs TV will indeed do "proper interlaced playback".

Exactly. See Angus' post previously.

it's just that they don't really do it by actually displaying interlaced lines ;)

I never said they did nor do I really care how they do it. I said that you can see proper interlaced display and that interlaced footage looks smooth like it should compared to progressive scan footage. However they do it, what they do NOT do is deinterlace like a NLE and change interlaced footage to fake progressive scan like a Z1U.

Roger

[christoph]

I never said they did nor do I really care how they do it. I said that you can see proper interlaced display and that interlaced footage looks smooth like it should compared to progressive scan footage. However they do it, what they do NOT do is deinterlace like a NLE and change interlaced footage to fake progressive scan like a Z1U.

actually that's exactly what they do, only at twice the the frame rate, ie 59.94 instead of 29.97fps...

so in that respect, kent is right saying that a consumer LCD monitor can't do true interlaced playback, and you are right in saying that it looks as smooth as an interlaced CRT TV.

and so everybody is happy (including me ;)
++ c.

[MovieStuff]

I never said they did nor do I really care how they do it. I said that you can see proper interlaced display and that interlaced footage looks smooth like it should compared to progressive scan footage. However they do it, what they do NOT do is deinterlace like a NLE and change interlaced footage to fake progressive scan like a Z1U.

actually that's exactly what they do, only at twice the the frame rate, ie 59.94 instead of 29.97fps...

Ah! Now that makes sense. I remember watching an experimental 16mm film about 20 years ago that a guy shot at 60fps and the projected on a special projector at 60fps. Looked just like interlaced video with all the same motion characteristics.

so in that respect, kent is right saying that a consumer LCD monitor can't do true interlaced playback, and you are right in saying that it looks as smooth as an interlaced CRT TV.

and so everybody is happy (including me ;)
++ c.

Well that's all that matters..... ;)

Roger

[Uppsala BildTeknik]

so in that respect, kent is right saying that a consumer LCD monitor can't do true interlaced playback, and you are right in saying that it looks as smooth as an interlaced CRT TV.

and so everybody is happy (including me ;)
++ c.

Haha, isn´t that the perfect end of an arguement/discussion!
So cool, really.

[David M. Leugers]

Christ, now I know I hate video... 8)


David M. Leugers