workprinters at 18fps?

[MovieStuff]

Hmmm, I still have my doubts... I believe all flatscreens are progressive, in that case a non-interlaced pulldown and viewing the film without any de-interlacing should give a better image quality.

Is it really possible that the interlaced pulldown looks smoother after de-interlacing than a non-interlaced pulldown does without de-interlacing (on the same high quality TV)? I hope that made sense...

All flat panel TVs, whether plasma or LCD, are inherently progressive.
1080 line transmissions are interlaced to save bandwidth, a technique used since the very earliest days of electronic television.
The TV (or the receiving box) has to de-interlace the picture at some point.
Whether this causes a degradation or not is a bit of a moot point, as the de-interlacing process cannot be avoided.

The video processors built into most HDTVs lack the processing power to deinterlace high-definition video well, which is why some AV enthusiasts are willing to spend £1000 or more on a high quality external video processor.

With a 1080i source the difference between screens will be down to the electronics in the screen. Converting a 1080i picture to 1080p is a non trivial task and external boxes capable of doing this well start over £1,000.

But if you are comparing a standard screen that is 1080i and one that can take 1080p there is unlikely to be much difference as both efectively have to traslate the image to a progresive format for display (from the 1080i source).

I did a quick googling just to get some references for my flatscreen de-interlacing ideas. All above quotes are from: http://www.digitalspy.co.uk/forums/show ... p?t=575615

I believe that this supports what I previously stated, which is if you have a good flat screen, it will emulate interlaced display correctly (like on my $ony Grand Vega) while a cheaper flat screen will not. As the above info states, how well it does is is dependent the electronics.

Roger

[Uppsala BildTeknik]

I believe that this supports what I previously stated, which is if you have a good flat screen, it will emulate interlaced display correctly (like on my $ony Grand Vega) while a cheaper flat screen will not. As the above info states, how well it does is is dependent the electronics.

Roger

Surely you must mean it "de-interlaces" the image? Cheap and expensive flatscreens do this with different result (cheap does not look as good, obviously).

If the screen in fact is showing progressive images at all times (and not interlace fields), shouldn´t the image look better if it didn´t need de-interlacing?

Or, if it indeed can show interlace fields (60 per second or 50 per second, NTSC or PAL), there would be no need for de-interlacing at all, and I have yet heard of any flatscreen panel than can show interlaced images, really.

The only way a screen can emulate a interlaced videofeed on a progressive screen is by de-interlacing (the whole de-interlacing can be done in quite a few different qualities, but they are all effectively still de-interlacing the images that we feed them with).

[MovieStuff]

I believe that this supports what I previously stated, which is if you have a good flat screen, it will emulate interlaced display correctly (like on my $ony Grand Vega) while a cheaper flat screen will not. As the above info states, how well it does is is dependent the electronics.

Roger

Surely you must mean it "de-interlaces" the image? Cheap and expensive flatscreens do this with different result (cheap does not look as good, obviously)....

I think it depends on what you mean by "de-interlace" as there are two definitions, just like the term "pulldown" means something different on a projector than it does in telecine. To make it more clear, let's not talk about film transfers and just look at live interlaced video footage. If you have an interlaced image and you de-interlace it on your NLE, then one field is dropped and replaced by artificial information that is interpolated from the surrounding fields or through mere field duplication. So that would be definition "A". That is how most progressive scan consumer camcorders like the DVX100a produce 24p footage. It isn't really true progressive scan at full resolution because half the information is lost.

So the act of "deinterlacing" in that context produces different results than one would expect for display because, if a monitor did that as a matter of operation, then any sort of live interlaced video footage would suddenly look progressive (or fake progressive ala the DVX100a). There would be no need for progressive scan cameras at all since one could just shoot interlaced and know that it will always look progressive on display. But, of course, that isn't the case. Progressive scan footage, whether true progressive or fake progressive, always looks different on a flat screen than standard interlaced video footage.

So "de-interlacing" in a television really refers to separating the incoming field information on the fly and, as noted in the info you provided, all televisions must deal with it somehow. That would be definition "B". But how those resulting fields are then displayed is what makes a difference, visually. If they are displayed sequentially, then interlaced video will retain the motion characteristics typical of motion that is spread across 60 increments (for NTSC). But if the fields are displayed at the same time on cheaper flat screen monitors, (without proper deinterlacing as in definition "B") then it will have a kind of smeary, quasi-progressive look that is somewhere between interlaced and progressive - like when interlaced footage is transfered to motion picture film and a single film frame contains both fields at once. That is why el-cheap table top flat screens don't show interlaced motion worth spit but my $6000 Sony Grand Vega displays live interlaced motion just like a giant CRT. It's all about how much you spend on the flatscreen.

Roger

[Uppsala BildTeknik]

If you have an interlaced image and you de-interlace it on your NLE, then one field is dropped and replaced by artificial information that is interpolated from the surrounding fields or through mere field duplication. So that would be definition "A".

Agreed. How this "progressive" image is built up is what differs between different de-interlacing softwares/scalers.

So the act of "deinterlacing" in that context produces different results than one would expect for display because, if a monitor did that as a matter of operation, then any sort of live interlaced video footage would suddenly look progressive (or fake progressive ala the DVX100a).

Well yes... isn´t that exactly what the software in the flatscreen TV does? (in different ways, depending on cheap/good TV and so on).

There would be no need for progressive scan cameras at all since one could just shoot interlaced and know that it will always look progressive on display.

There would, since the de-interlaced footage only looks "fake-progressive" and doesen´t look as sharp as "real-progressive" footage would.

Progressive scan footage, whether true progressive or fake progressive, always looks different on a flat screen than standard interlaced video footage.

I think this is because the TV doesen´t see any need to de-interlace the footage, so it isn´t put through the de-interlacing system in the TV.

So "de-interlacing" in a television really refers to separating the incoming field information on the fly and, as noted in the info you provided, all televisions must deal with it somehow. That would be definition "B".

Yes, to produce "fake-progressive" images that it can display without any interlacing artefacts visible to the viewer.

What is the difference between a image de-interlaced in, lets say Final Cut, and a image de-interlaced in a TV? (other than the natural difference due to different softwares using different calculations in the de-interlacing somehow, depending on the good-bad TV and so on)

But how those resulting fields are then displayed is what makes a difference, visually. If they are displayed sequentially, then interlaced video will retain the motion characteristics typical of motion that is spread across 60 increments (for NTSC).

Sounds to me like a true interlaced monitor?
If it indeed shows the interlace fields one-by-one sequentially, 60 times per second... wouldn´t that mean that the monitor is capable of displaying interlaced footage without any de-interlacing at all?

I thought flatscreens wasn´t able to do that.

But if the fields are displayed at the same time on cheaper flat screen monitors, (without proper deinterlacing as in definition "B")

Hold on here, I thought that flatscreens needed to show full images, progressive images, hence the need for de-interlacing.

What the proper de-interlacing (and all de-interlacing actually) does is that it somehow "melts together" the interlace fields to one "fake progressive" image it can display.

The difference between good and bad ways to de-interlace is that a good de-interlacing looks better than a bad de-interlacing. But they are both still de-interlaced (since that is necessary in order to show the interlaced footage, without people being able to see interlacing artefacts (those ugly lines fully visible).

[MovieStuff]

.......The difference between good and bad ways to de-interlace is that a good de-interlacing looks better than a bad de-interlacing. But they are both still de-interlaced (since that is necessary in order to show the interlaced footage, without people being able to see interlacing artefacts (those ugly lines fully visible).

You are still confusing the term "deinterlace" as it applies to NLEs or televisions. It does not mean exactly the same thing on both though both deal with separation of the fields. Deinterlacing on a NLE system eliminates a field. You will never see that field again. It is forever gone and the resulting footage will look deinterlaced or fake-progressive on both flatscreen or interlaced CRTs. But deinterlacing is a process in a television prior to display that does not eliminate any field information. Deinterlacing in a television merely separates the field information prior to display. If the monitor is a good flat screen monitor then -after deinterlacing to separate the fields- it will sequentially display both fields one after the other for true interlaced display, like a CRT normally does. If it is a crappy table top flat screen, then it will not and you will get a crappy, smeary image.

As I said previously, it all depends on how much you spend on the flatscreen but good ones will display interlaced footage correctly and there will be a noticable difference between interlaced video and progressive scan video. I

Think of it like this: If the monitor always deinterlaced the interlaced video just like a NLE system does, then the image will always look just like footage from a camera that uses deinterlacing to produce fake progressive scan footage. That simply is not the case. If it was, then there would be no need for progressive scan cameras that use deinterlacing because the monitor could be counted on to drop one field on display instead of having the camera do it during shooting. Also, if all flatscreens deinterlaced like an NLE, then there would no noticable difference in motion characteristics of interlaced footage and progressive scan footage.

All monitors have to separate the fields before display. How well they do it is based on the cost of the monitor but deinterlacing inside a television does not mean the same thing as deinterlacing on a NLE system.

Does that make sense now?

Roger

[Uppsala BildTeknik]

If the monitor is a good flat screen monitor then -after deinterlacing to separate the fields- it will sequentially display both fields one after the other for true interlaced display, like a CRT normally does.

....................

Does that make sense now?

I understand your explanations, but it doesen´t make sense to me...
It goes 180 degrees against everything I thought I knew about flatscreens (all digital screens, LCD or plasma), I thought they did not have the ability to show one field after the other, like a true interlaced monitor (like a CRT).

I tried to find some content on the internet that would confirm that there are flatscreens capable of displaying interlaced images, but I couldn´t find any. I did find this though:

It is not possible to view any 480i images at 480i on any digital display. Digital displays are inherently progressive scan, and the issue with the Z4 is NOT poor scaling, but is poor deinterlacing. This means, that for regular DVDs you should at least get one that is halfway decent at DEINTERLACING. This is relatively easy, and not very expensive to get. If you aren't interested in this, you can always switch to the Panny AE900 which has better deinterlacing and similar scaling.

I personally only watch HD material and progressive DVDs on my projector... It works very well when you feed the projector the best image possible.

Hmmm, then I found this, from NAB 2007:

Sony revealed a new line of master monitors with innovative LCD technology. The introductory 22.5” BVM-L230 LCD video reference monitor rivals Sony’s BVM CRT monitors by implementing flat screen technology, which has a lower weight, power consumption, and heat load.

The BVM-L230 LCD includes Sony’s Trimaster technology, which produces higher levels of color accuracy and reproduction and a wide color gamut panel. Trimaster technology also supports full HD resolution at 1920 x 1080 and high gray-scale gradation.

Sony’s new flat screen LCD is equipped with a new color space selection function, advanced picture-and-picture display, and a true interlace display mode, which helps to accurately reproduce interlaced signals.

I guess it is a new feature or somehing... Never heard about it before, I have always found myself reading about upscaling and de-interlacing. Never about a digital ftlatscreen that displayed interlaced images perfectly without any need for de-interlacing.

Interesting though that they wrote "helps to accuretly reproduce interlaced signals", instead of "reproduces interlaced signals in a true interlaced mode", or something like that. It surely is such a big news that they should be more detailed about it.

Ah, well... all these new thingies on the TVs...

8)

[christoph]

maybe i can shed some light on this..

there are 3 different types of LCD:

- computer LCDs
- TV LCDs
- broadcast LCDs

computer LCDs have some serious limitations:
they only run at progressive 60Hz, they have the wrong color gamut and they can't display interlaced. as such, you'll always have artifacts even if they have a real video in like HMDI or S-Video

TV LCDs can usually run at 50 or 59.94Hz, which means they can display one field of video at the time. it's not true interlaced though because they will show 50/59.94 deinterlaced images (ie the fields will be spread over the full display high without any gaps in between). some more expensive units do twice the refresh rate to reduce flicker (or try to calculate in-between frames stutter on progressive material).

broadcast LCDs can display true interlaced (ie only one field at the time) and can display 23.98p/24p/25p/29.97p/30p/50i/60i.
the cheapest one i know is the panasonic 17", which runs about 3000. the sony bvm series is much more expensive.

btw, the difference to deinterlacing footage in a NLE is that the NLE will calculate a 25/29.97p progressive signal while the TV will calculate a 50/59.94p. the later is obviously smoother, but not neither is the same as shooting true 24/25p. also, the DVX *does* have a true progressive ccd and applies a pulldown that can be removed lossless (well, as lossless as you can get with DV) on the american model (in europe you get 25p directly without all the hassles).

++ christoph

[MovieStuff]

maybe i can shed some light on this..

there are 3 different types of LCD:

- computer LCDs
- TV LCDs
- broadcast LCDs

computer LCDs have some serious limitations:
they only run at progressive 60Hz, they have the wrong color gamut and they can't display interlaced. as such, you'll always have artifacts even if they have a real video in like HMDI or S-Video

TV LCDs can usually run at 50 or 59.94Hz, which means they can display one field of video at the time. it's not true interlaced though because they will show 50/59.94 deinterlaced images (ie the fields will be spread over the full display high without any gaps in between). some more expensive units do twice the refresh rate to reduce flicker (or try to calculate in-between frames stutter on progressive material).

broadcast LCDs can display true interlaced (ie only one field at the time) and can display 23.98p/24p/25p/29.97p/30p/50i/60i.
the cheapest one i know is the panasonic 17", which runs about 3000. the sony bvm series is much more expensive.

btw, the difference to deinterlacing footage in a NLE is that the NLE will calculate a 25/29.97p progressive signal while the TV will calculate a 50/59.94p. the later is obviously smoother, but not neither is the same as shooting true 24/25p.

Thanks for the info.

also, the DVX *does* have a true progressive ccd and applies a pulldown that can be removed lossless (well, as lossless as you can get with DV) on the american model (in europe you get 25p directly without all the hassles).

I know that the DVX will produce progressive scan frames but the DVX100a that I have clearly seems to do it via deinterlacing. The image when you use progressive is about half resolution than when using interlaced. In fact, if you take interlaced footage from the DVX100a and then deinterlace on your NLE using interpolation, the footage looks identical to the progressive scan frames produced by the DVX100a. It has been my understanding that's how most budget prosumer camcorders produced "progressive" frames, including the Sony's HD HVRZ1U, which I also have. When you go to the progressive mode on the Sony, even if the camera is locked off on a tripod and there is no movement of any kind, you can see the resolution drop dramatically. The same with the DVX100a. If they were both producing native, true progressive scan frames, then the resolution would be the same whether the camera was in the interlaced mode or the progressive scan mode, wouldn't it? So why does the progressive scan mode show a drop in resolution?

Roger

[christoph]

I know that the DVX will produce progressive scan frames but the DVX100a that I have clearly seems to do it via deinterlacing.

thatt's odd, either your model is severly screwed up, or your method of removing pulldown is not correct. you should record in 24Pa mode and use a video app that supports this mode (i know final cut does).

It has been my understanding that's how most budget prosumer camcorders produced "progressive" frames, including the Sony's HD HVRZ1U, which I also have.

that's true, the Z1U (and Z1E) has an interlaced CCD, so any progressive mode is a real-time deinterlacing method. worst of all is the 24F mode on the Z1U model, as it appplies a fake pulldown to the deinterlaced, dropped frame 24fps stream, which means there's no way to get true 24P (or 60i) back from it again.
the JVC HDV and the sony V1 and do true 24P though, as do the DVX and the HVX and some others.

So why does the progressive scan mode show a drop in resolution?

as said, i can only assume you either have some wrong setttings while shooting (the DVX *can* do interlaced too) or while removing pulldown.
i only used the europe version myself, but i've shot one feature and 3 shorts on that, but i've read enough of the american model to know that it is truely progressive too.
++ christoph

[MovieStuff]

thatt's odd, either your model is severly screwed up, or your method of removing pulldown is not correct. you should record in 24Pa mode and use a video app that supports this mode (i know final cut does).

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. In fact, I haven't seen any SD prosumer camcorder that produces the same resolution picture in progressive as it does in interlaced mode. They all seem just to deinterlace to produce a fake progressive scan.

It has been my understanding that's how most budget prosumer camcorders produced "progressive" frames, including the Sony's HD HVRZ1U, which I also have.

that's true, the Z1U (and Z1E) has an interlaced CCD, so any progressive mode is a real-time deinterlacing method.

Right and the DVX100A supposedly uses true progressive scanning but I swear it does not have the same resolution in the progressive mode that it does in the interlaced mode. I looks good, don't me wrong, but it looks no different than shooting interlaced and then deinterlacing on the NLE using interpolation.

worst of all is the 24F mode on the Z1U model, as it appplies a fake pulldown to the deinterlaced, dropped frame 24fps stream, which means there's no way to get true 24P (or 60i) back from it again.

Oh it sucks, for sure. I only use the Z1U in the PAL mode for 25p. Never use the 24p mode because of the joke pulldown. Why did they even bother?

the JVC HDV and the sony V1 and do true 24P though, as do the DVX and the HVX and some others.

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

So why does the progressive scan mode show a drop in resolution?

as said, i can only assume you either have some wrong setttings while shooting (the DVX *can* do interlaced too) or while removing pulldown.
i only used the europe version myself, but i've shot one feature and 3 shorts on that, but i've read enough of the american model to know that it is truely progressive too.
++ christoph

It may be but the image is definately softer in the progressive mode than in the interlaced mode and I've use several of them on different projects. Again, they look good but there is a difference in clarity, for sure.

Roger

[Uppsala BildTeknik]

maybe i can shed some light on this..

there are 3 different types of LCD:

- computer LCDs
- TV LCDs
- broadcast LCDs

....................

Thanks for the info.

Yeah, computer LCDs I never even accounted for. The TV LCDs are the ones we were talking about (at leaast I did), and just as I thought they indeed do de-interlace the image. Apparently in a different way than a NLE, but still, they do not show the fields one-by-one.

The broadcast LCDs are interesting, I never thought about those, and never thought that they would show interlaced footage in a different way (I just thought they were better at showing correct colors, and a sharp image).

Have you guys heard about those ultra-thin LCDs by the way?

How thin? 20mm thin, increasing slightly to 29mm at their thickest part. Crazy isn’t it?

The bezel is just as slim, with the top coming in at 20mm at the top and 25mm on sides.

That was a 50" TV by the way, a crazy world... from the fat-TVs to flatscreen is a great leap in saving space, and looking good. But from normal flatscreen to 20mm... just sounds expensive to me. 8O

[MovieStuff]

Yeah, computer LCDs I never even accounted for. The TV LCDs are the ones we were talking about (at leaast I did), and just as I thought they indeed do de-interlace the image. Apparently in a different way than a NLE, but still, they do not show the fields one-by-one.

You still do not understand. Broadcast LCDs and TV LCDs are really only different from the perspective of budget. 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.

Roger

[Angus]

Hmmm, I still have my doubts... I believe all flatscreens are progressive,

Just to back up what Roger says, if I feed my LCD 1080i television with an interlaced PAL or NTSC signal it doesn't deinterlace in order to display them. It displays a smooth but interlaced video like one would expect.

If I use my USB TV stick on my PC it is picking up a PAL signal, and it is clearly deinterlaced for playback on the computer monitor. You get the telltale signs of deinterlacing every time anything moves. Its interestig to use a live TV signal and watch the two side by side.

Now...here's where it gets more interesting. If I convert my interlaced PAL signal to 576p and feed THAT into the television, it is now the TV doing any processing to get fluid motion. And it does a pretty good job...good enough that I usually watch PAL as 576p. But it looks subtly different to feeding an interlaced PAL signal to the same TV.

Thus far the only 1080i signal I've fed my TV came from an HD camcorder, and that's not ideal but it is impressive. I'll find out about broadcast 1080i on Saturday morning....

[johnnhud]

I like film.

[Uppsala BildTeknik]

You still do not understand. Broadcast LCDs and TV LCDs are really only different from the perspective of budget. I know plenty of people that spend $3000-$8000 on LCD displays for the living room...

Ummm, yeah. I don´t know anyone who has spent $8000 on a livingroom TV. I guess we have different perspectives about it.

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? :?