who said anything about film? LOL! This discussion has nothing to do with film "look". It has to do with delivery of progressively shot and interlaced video to be displayed on progressive televisions. Also, I would not try to feed my interlaced CRT a 30P stream because it's an interlaced set, so 60i works best. The bottom line is whether one chooses 60i or 30P, you're only getting 30 real frames/sec when the stream is pushed out to a progressive display.

I am with Ken. I don't want the "film" look I want nice smooth video to give me the impression "I am there looking through a window". Low frame rates cannot give this because they are unable to take enough frames to capture the motion. Its why 24p and 30p judder something I detest. I do not know how my Panasonic plasma deinterlaces but I can tell you that played from my camera it looks acceptable ( still not as smooth as a CRT) however transfered to a disc and played from the PS3 ( which upscales to 1080p30) it is not as good. I am beginning to think that I will not like Bluray if everything is 30p !!!! In my mind there is ample information in a high definition interlace stream to create a 60p stream rather than 30p since most of the image is not moving unless there is panning or zooming something the higher capture rate of interlace provides as an advantage over lower rate progressives. There are now lots of DVD players that will convert SD DVD's for display at 1080p. To me that's a much bigger task than interpolating the odd or even lines with motion detection. It would be nice to know if there are any progressives displays that do deinterlace to 60p not 30 with repeat frames.

Ron Evans

Actually, Ron, since most of BD releases are from Hollywood, the majority of BD discs are 24P, LOL!

And those BR discs originate on FILM and not video. There is a big difference in how video and film translate on BR. Some BR players do better than others in this respect, but yes, you will get buttery smooth motion with 24p film-based BR discs on fixed pixel displays. Getting that same smooth motion from videocameraas recording 24p is another matter.

Just found this which may be of interest to this thread.
http://digitalcontentproducer.com/hd...cing_2_011907/
I am well aware that Hollywood is likely film based at 24p my particular interest is in concerts/theatre which are more likely to have been recorded by video cameras and the concern I have is how these have been recorded. I would prefer higher frame rates because of the motion, especially on the near stage cameras or for dance. 24p or 30p just doesn't cut it for these situations. I have little interest in Hollywood films I actually do not own any, in any format, even tape.
Ron Evans

Yeah, that does shed some more light on this subject, but it also shows its age since everyone has moved on to native 24P support at the display. The article is also missing the topic of de-interlacing 30P in 60i. Steve is a member here, so I'm surprised he hasn't jumped into this discussion.

Ken, perhaps you can explain to me how 24 fps shot with a film camera is different than 24 fps shot with say a Panny HVX200 (after removing pulldown frames if shooting 1080P) assuming identical shutter speeds. I can dump both streams on a 24P timeline in Vegas Pro, edit, and render out to a 24P BD. How is it possible for the BD player to realize one part is derived from video while the other part is derived from film?

> QUOTE: Seriously, how can anyone argue that capturing half of a frame and then capturing the second half of the same image 1/60 sec later is better than simply capturing the entire frame all at the same time?

If its footage with motion, I'd rather have some visual info every 1/60th of a second, rather than every 30th, thanks. I decided that after owning a 30p JVC HD1 for 6 months a while back .. replaced it with a 60i Sony.

Obviously I'd prefer 60p (and in fact I often use software to deinterlace 1080i60 to 720p60) but 60i will do for now.

Maybe he doesn't frequent all of the threads in the forum, I know I don't - there are so many of them. But judging from the article, I agree he might be a good voice to have chime in here.

I think film looks smoother partially because of the art and experience behind it. 24 fps juddering is most noticeable during pans and zooms at certain speeds, so professional filmmakers try to avoid pans and zooms in certain speed ranges that tend to look bad. Every once in a while it can't be avoided and you do occasionally see a juddery pan in a film, but it seems pretty rare. Since a certain amount of motion blur helps, I imagine they also try to keep the shutter speeds down within a certain range by using slower film or neutral density filters when shooting outdoors (just guessing here).

Aaron, therein lies the problem with video-based HD on BR. Some players are quicker to recognize the flags (assuming they're properly implemented on the DVD...many are not) and thus more properly reproduce the source as intended. Other players pick up on the sequences late or not at all, creating motion or resolution issues. I don't profess to be an expert in this, but I've seen the end results in some of the players I've had.

The bottom line in my mind is that the vast majority of the displays today are fixed pixel. So issues or not, that's the display technology of our day. If for whatever reason 24p or 30p look worse relative to motion handling, why would I not want to go to 60i if I find this motion handling disturbing? Why should I have to jump through hoops to obtain the buttery smooth motion of 60i by simply rolling the footage? To top it off, I've yet to see any 24p or 30p video that remotely resembles the 'film look'. But again, that's just me.

What's the point if the de-interlacer is simply going to merge those two fields into a complete frame for display on a progressive television? What's more, the motion that you just spoke of that occurred between those two 60i fields must be blurred by the video processor in order to prevent our eyes from detecting those hard edges when those two fields are weaved together. 60i is only yielding 30 real fps, as captured by the camcorder, any way you cut it on a progressive display.

The reason you did not like your 30P JVC is because 30P was being delivered via 60i and your display chain did not properly de-interlace 30P in 60i.

Ken, yeah, you're right. 60i is and will continue to be universally supported. It's unfortunate that the consumer electronics industry is having these growing pains because it limits our choices with video work. Hopefully, things will improve in the next year or two.

Motion adaptive deinterlacing software is more effective than you give it credit for. I invite you to try it sometime and view the results frame by frame in something like Virtualdub. Please note that I said reducing 1080i to 720p ... that has implications for the edges you are concerned about.

Deinterlacing 30P? Interesting concept....

^^^30P is always delivered via 60i with these camcorders and BD media.

Regarding 1080 vs. 720P, as I've said earlier in this thread, if you're happy with 540 lines of real rez, then you may as well go ahead and stick with 720/60P and get real HD video.

Aaron, you are totally incorrect regarding 720p vs 1080i resolution. There is unquestionably greater resolution in a 1080i broadcast. It's measured and it's observable. I'm surprised at this late date that people still think you're only getting 540 PIXELS of resolution. You also forget that resolution is measured in two directions, horizontal and vertical. Both those numbers are higher with 1080i and thus the significantly higher resolution for 1080i.

Now if you want to make a case for the resolution dropping during periods of rapid movement in a 1080i broadcast, you're now on firmer ground. However, what is not widely known, is that well over 90% of scenes on broadcast TV have little to no movement...yes, even during sports telecasts. So this is why people with 1080p TVs (like myself) can easily see the added resolution provided by 1080i.

Yes, 1080p would be the best, but it sure isn't happening anytime soon when broadcasters barely have the bandwith for 1080i.

I found another interesting web page about deinterlacing, including some information about how deinterlacing material that was originally progressive can degrade it (i.e., deinterlacing 30P material that has been converted to 30P in 60i):

http://www.100fps.com/

This is the first site I've seen that shows that there are both deinterlacing methods that result in 30 fps video (as Aaron and I have been saying), *and* deinterlacing methods that result in 60fps video. Bobbing+rescaling and bob+weave both can result in 60fps video, with bob+weave being better because it's motion adaptive and does a better job of preserving vertical resolution in static areas.

So, maybe I've been wrong - if a TV uses a motion adaptive method that includes bobbing, such as bob+weave, then it is possible that these TVs actually generate a "synthetic" 60 fps from the two fields, and thus 60i video would look more fluid on a 60p display than 30p 2:2.

There have to be some test video patterns one can generate to help figure out what a given TV is doing.

I think there is one other area in which 1080i would have reduced resolution even in static scenes. Broadcasters often blur interlaced video vertically so that sharp horizontal lines don't twitter on interlaced displays.

So when comparing 1080i to 720p, the improvement in horizontal resolution may be greater than the improvement in vertical resolution.

You could be right Dave, but the disparity in resolution between 720p & 1080i is actually much greater in the horizontal, so that again provides the argument for 1080i's picture quality advantage.

Ken, re-read what Graham is doing. He is taking each 1920x540 field and instructing his video processor to scale that field to a 1280x720 frame to obtain 60 frames/sec from 60 FIELDS/sec. I suppose that's ok from a consumer cam POV; but I still stand by my original statement that you may as well use a 720/60P cam to start with then (understand they don't really exist in the consumer space and that's too bad).

Aaron, yes, from that perspective I agree with you. I was arguing the case for 1920X1080 vs 1366X720.

Dave the 100fps site has some things wrong. IT implies that all digital video is recorded at 30fps by combining the fields in the camera before recording to tape. This is not true. The DV codec has the ability to compare fields and if there is no perceived difference/movement will combine into a frame to save data recorded to tape and allow more bandwidth for other areas. But normally the recording is field based not frame. Sort of makes me suspect the other information on the site. For more detailed info on DV etc see http://www.adamwilt.com/DV.html
I am still trying to find info on displays that say how wthey de interlace, specifically not marketing stuff. It is clear there are big differences as playback from my FX1 or SR11 to Panasonic or my iARt CRT are very different than an SD DVD from the same sources played back from a Sony DVD player or from the PS3!!! The PS3 upscales to 1080P30 and although the image has more detail it has a lot of Judder!! Haven't had the time yet to play around with different encoders etc.

Ron Evans

Ron, yes, I do agree that the site may not be entirely accurate, but I think the main thing I pulled from that site is that it is possible to do deinterlacing in such a way that you obtain a synthetic 1080/60P video stream (60 fps). I had always been assuming that all deinterlacing results in a 30P video stream which is then always displayed in 2:2 pulldown on 60Hz TV's.

I think what this brings to the argument is that although nobody here is 100% sure at the moment, it is at least possible that *some* TV's *may* be doing interlacing in such a way that they generate 60 fps frames from some combination of bobbing, scaling and weaving the fields.

If some TV's do this, it could certainly explain why 60i seems more fluid to many people, because possibly it is on their particular TV. It could also explain why you get such different results from the same source material depending on where the deinterlace is done and how it was done.

I'm also going to play around a bit with encoding. I like the idea of using 720/60P as a temporary stop-gap until most TV's have good motion compensated de-interlacing, as most TV's have good scaling even if they have poor deinterlacing. I just think you might get a better result by starting from *properly* deinterlaced 60i, which can be done on a PC (deinterlace to 1080/60P using motion adaptive bob+weave) and then down sampling to 720P rather than starting with 540 line fields and up-sampling to 720P. If I get it all working, I'll post here.

For those familiar with AviSynth, here's a simple 1080i60 to 720p60 avs script to play with:

AVIsource("02.avi")
assumetff
tdeint(mode=1)
#use mode=0 for 30P or mode=1 for 60P
lanczos4resize(1280, 720)

There are better deinterlacers, like McBob, but I find TDeint to be a good tradeoff between quality and speed. It's downloadable here: http://bengal.missouri.edu/~kes25c/TDeintv11.zip

Wow! What good timing. I just tried the same thing, but using Avidemux2. The deinterlacer I found to work the best was DGBob, which is motion compensated and can double the frame rate. Here was the filter stack for Avidemux2 that I used:

1. Deinterlace - DGBob with threshold 12 and frame rate doubling
2. mPlayer resize to 1280x720 with lanczos interpolation
3. mSharpen with strength of 70 and threshold of 15

The small amount of USM (step 3) was to add a small amount of EE as pre-compensation so that edges are preserved a little better on upsampling to 1920x1080. After upsampling, the EE is no longer visible but the edges are sharper.

I was surprised how well it worked. the DGBob deinterlacer worked well, the resulting 60 fps frame rate gives smooth playback even on a PC, and the little bit of EE caused the edges to stay fairly sharp even after upsampling.

This type of video can be distributed on BD, and might look better than 1080/60i or 1080/30PsF on lower end TV's that don't interlace well.

Dave, you can include playback devices in that category too, as well as AVR's. This is all a very complicated mess that unfortunately the consumer now has to deal with because poor decisions were made in the past. It's really too bad that you either have to become an expert on practically every CE subject today, or find an authoritative review before buying just about any piece of gear now.

The variations that you speak of are likely the result of proprietary video processing algorithms employed by the various chipset manufacturers in an attempt to differentiate their products from one another. And that's a good thing; but the flipside is it creates this vast "unknown" regarding your distributed project if you try to chart virgin territory.

I will continue to bug these manufacturers and try to get answers to these de-interlacing questions WRT their video processors and the implementation of those processors in certain key A/V components. Any info I get from them will be added to this thread...

Yes, this is why I haven't bought a TV yet. Obviously I'd like to get one that does a good job of deinterlacing both 24P 2:3 and 60i (perhaps even generating a good quality 60P stream from the 60i), but even though I'm a technical person and have some idea of what is technically possible, it's so hard to actually find out what products actually do what, and I don't have 8 hrs. a day do devote to research.

Having said that, there seems to be more standardization in how the camcorders behave, e.g., they all generate 1080/60i in more or less the same way (ignoring details like rolling vs. global shutter), and some can generate 24P in 60i and 30P in 60i. So I'm thinking the correct order is to first get a camcorder, then take the camcorder with you and view the video on the different TVs. You can't determine everything this way, such as how the TV handles true 24P or true 30P, but you can at least compare how well they deal with interlacing.

I suppose the good news is that even though interlacing is not going away any time soon, the processor chipsets are getting better and in a year or two most TV's will be able to deal with it (and 30PsF) much better.

Hopefully you'll hear something back from the chipset makers ;-)

I was told that in a choice between 60i and 24p, use 24p for more professional looking work. It's less clear whether one should use 30p or 24p, but as for the effects, 30p will produce a nice, clear, progressive image that produces less motion blur than the 24p recording would, without interlacing.

So, I'd say use 30p if you have it, and if you don't, 24p if you're shooting on a tripod and know to make slow, fluid movements, 60i if the subject's more unpredictable or you're operating handheld.

Actually picking the best TV is one of the easier jobs today. Every review has called the latest generation of Pioneer Kuro displays the 'best ever'. Seldom have I ever seen such universal praise for any AV product.

Owning two, I can attest to their unbelievable picture quality. And yes, they perfectly deinterlace, but you do get some motion jitter with 30p in a 60i stream. I don't believe any display will show buttery smooth motion from this 'wrapper'. However, you do get buttery smooth motion from every other source I've ever fed it. The Pioneers have something called "smooth" processing which even helps smooth out motion judder inherent in some 24p BR discs. It's almost weird to see such smooth playback of scenes you know contains this judder. That processing can be engaged or disengaged, your choice.

Highly recommended!

Thanks, Ken. Yes, the Kuros come highly recommended from a number of sources, so in that sense I guess it's an easy choice. But they are also near the top of the heap price-wise. I know you get what you pay for, but I was hoping to find something more mid-priced that still had decent signal processing performance. The new crop of Panasonics due out soon are rumored to have improved signal processing and might be more mid-priced, so I may wait a bit and check them out.

I might end up wanting a Kuro, but I will have to build up some courage before trying to get a $5,000 TV past the finance committee ;-)

Yeah Dave, generally that 'finance committee' demands something in return. That can be a very expensive proposition! ;)

Aaron, why do you state that as if it were an established fact? It hasn't been proven by the discussion and links in this thread. In fact, at least 2 of the linked articles have mentioned deinterlacing methods for 1080i that yield 60fps output.

Consider, for example, the digitalcontentproducer article. The descriptions given for the "Bob" and "2D FIR" methods specifically say that frames are output each field time, i.e. 60fps. Those methods by themselves don't seem very desirable, but how about this one:

"A Vector Adaptive interpolator uses memory to hold four fields. Logic measures motion between fields. For static video, weave is employed. For dynamic video, samples come from the current plus a previous and/or a future field."

The article unfortunately doesn't specifically say if this method would output frames at 30 or 60fps, but it 60fps seems feasible.

In any case this is all theoretical, because different displays and video processors certainly use different methods. I don't think anyone can make a blanket statement that all fixed pixel displays render 1080i as 30fps or 60fps. It seems that we're left to test our own particular equipment and judge the results for ourselves. It's unfortunate that this is not more standardized.

Traditionally, de-interlacing for playback on a progressive display has always meant recombining the two fields that contain the original frame. The fact that several video processing manufacturers have moved well beyond that idea with proprietary algorithms designed to create 60 frames per second from 60 fields per second is really immaterial at least IMO. They are trying to create something that did not exist as these images were laid to tape, flash, HDD, or whatever in cam. I'm not saying it doesn't work, just that it is not the same thing as capturing 60 full rez frames per second.

I think it is more appropriate to call interlace cameras 60 fields per second cameras because they never capture frames at all, or record frames to tape or whatever, its always fields. They take a field every 1/60 of a second. The field just happens to be half the vertical resolution in discrete horizontal strips( one odd the next field even). That is very different from a picture with complete cover at half resolution. Thus the scene capture rate is 60 fps not 30 fps its just that only half the horizontal strips are being recorded at a time. This of course is very different from a camera capturing 30 frames per second and then processing field information to record. With a CRT phosphor decay our eyes still see the last field when the next is displayed and that is why we perceive a full image at what appears to be 60 fps, not 30 fps. The screen refresh rate is 60hz and the image actually changes every 1/60 sec( just not all of it,but that is true of most images anyway and why it works so well) Our eyes/brain interpolate the missing/decaying horizontal lines and that is what I would hope modern electronics should do on a progressive display. It would be nice to know what manufacturers are creating 60fps though.

Ron Evans

Ron, good explanation. People do get confused with frames and fields and that appears to be why many feel that half the resolution is lost when its not. I do believe that Pioneer at least is creating 60fps in their propietary 'smooth' mode.

Ron, yes, the traditional summary way of saying what you said is that interlaced video transmits static or slower motion in full resolution at the frame rate, and fast motion in half the vertical resolution at the field rate.

That's the compromise of interlace. You can't have fast motion at full resolution unless you go to full progressive 60 frames per second.

And, yes, it sure would be nice to have a table or list showing which deinterlace methods are used by the various TV's. Someone linked to a page earlier in this thread that lists TVs known or believed to display 24P properly (by shifting the refresh rate, and the Kuros are on that list). Perhaps TVs that have higher quality 24P display also have higher quality deinterlacing in general.

Also of interest may the latest Amberella info.
http://www.ambarella.com/news/press_...r_01072008.htm
Would be interesting to know which cameras use this latest chip too.
Ron Evans

This is definitely a move in the right direction. It may be a long time before broadcasting moves to 1080/60P because of bandwidth limitations, but there is no reason at all that camcorders can't move in that direction. I don't know if the BD spec supports 1080/60P (anyone know?), but if it doesn't, it should be added. Right now, the 60 fps progressive capability of most newer TVs is being partially wasted (unless you've got it hooked to your computer and are playing video games).

The BD disc capacity is so large that there's no reason that movies can't also finally move up to 60 fps, except that the film industry is so attached to the ancient 24 fps look. It sounds stupid, but I'm afraid our great grandkids will still be watching movies at 24 fps 100 years from now.

Knowing how long product design cycles tend to be, I'd be surprised to see this chip even in 2009 model camcorders, but maybe...

Dave, pretty sure the answer to BD spec and 1080p60 is "no" as of today. I guess that means all of the players today will be obsolete as soon as that format is ratified by the BDA because I highly doubt a simple firmware update is going to work. Guess we shall see in the next "X" number of years (before they get their act together).

Ron, GREAT find! A lot of that press release sounds pretty familiar, hmmm? Comparing it to the information presented in this thread, someone might get the idea that I actually wrote it, LOL! It's kinda comical to read between the lines and catch their pitch for their product.

Yes, I would think decoding 1080/60P might require additional processing power, so it probably won't be just a firmware update, unless some manufacturers are already anticipating it. On the good side, in a year or two, that second BD player with new capabilities will cost a *lot* less than your first one did ;-)

This concurrent shift to both hi-def and progressive displays is the biggest shift in consumer video technology since TV was introduced, so unfortunately it's taking a few years for things to settle out.

There's an interesting white paper posted at the Amberella site:

http://www.ambarella.com/docs/1080p60.pdf

This talks about using 1080/60P for broadcasting. Initially, one would think that this would take nearly twice the bandwidth of 1080/60i, but it turns out that due to the higher level of vertical correlation within a frame, that it actually takes only around 20% more bandwidth for the same quality.

Another nice find, Dave. Even though there are some typo's in that paper, I think it nicely summarizes a lot of the content of this thread and corroborates what the MIT expert wrote and argued in front of the ATSC adoption panel.

Yes, to me one of the more interesting points of the paper is how broadcast infrastructure is now lagging consumer electronics technology where it has always been ahead in the past. The same thing is soon going to happen with color space as in a year or so most all TV's sold will be xvYCC capable. It will be rather ironic in a year or two when a consumer can go from production to display in 1080/60P xvYCC before broadcasting has even adopted one of those new technologies.

Of course the problem is that the broadcasting infrastructure is large and expensive to change, so it will happen more slowly. Nonetheless it's amusing to see that in some respects the envelope is now being pushed by the consumer end.