What I find interesting is that my own HDV, DV or AVCHD seem to play much smoother and with apparent higher resolution for the AVCHD and HDV on the Panasonic than even the few BluRay discs that I have, they are concert videos so likely not from 24p film?

Funny you mention this because most concert videos are being shot at 1080/30P. So you're experiencing firsthand exactly what we're discussing here.

Actually much of the problem with 24p video on DVD rests with the DVD player and not the HDTV.

Aaron the interesting part is that within the BluRay of Shakira concert in Miami the long shots are really nice and actually look higher resolution than the close shots from the cameras in front of the stage which also have judder in the backround. IT seems that some cameras have judder and some don't as if the cameras were shooting at different frame rates!!! Interestingly the BluRay of Queen in Montreal, which was shot on film, in some respects has less judder than the Shakira disc. I don't know if this is due to the camera persons for Queen being used to film technique and thus manage the judder better than the modern camera persons using 30P for the Shakira concert!!!! Suffice it to say the Nora Jones SD video is better than either of these BluRay discs as far as motion judder is concerned. All discs played from my PS3 with latest firmware viewed on my Panasonic 42" 1080p Plasma.
THe first Nora Jones DVD is much better than the second by the way.

Ron Evans

There is some conflicting info in this thread about how fixed pixel displays handle interlaced video. A few users said that 60i is deinterlaced to 30p. Others say that video recorded in 60i gives smoother motion than 30p. Both of these assertions can not both be true.

I have not been able to find any definitive references on the subject, but let's look at it logically. Assume that we have a native 60i video source and a modern fixed pixel display. If the 60i input stream was simply deinterlaced to 30p, then half of the motion resolution of the original 60i source would be lost! A better approach would be to use intelligent processing (deinterlacing, interpolation, etc.) to generate 60p, thereby retaining the full motion resolution. This would explain why some people perceive 60i to give smoother motion than 30p, and also why the camera manufacturers continue to use 1080/60i as their primary recording mode. If 60i was reduced to 30p on playback, there would be no reason to record in 60i.

Therefore it seems logical to conclude that modern fixed pixel displays process 60i input to produce 60p display, and 60i video does in fact give better motion handling than 30p. If anyone can prove me wrong, please do. :)

I think that you may be correct Bob. I can playback from two players onto my Panasonic 1080p plasma. From an older combined DVD/VHS Sony player and from a PS3. The PS3 is connected by HDMI and will upscale to 1080p playing back DVD's. There is noticeably poorer motion from the PS3 over HDMI than from the older Sony DVD over component. OF interest is that playback over HDMI from my SR11 is smooth!!! So the PS3 conversion is not doing as good a job as the Panasonic.

Ron Evans

Therefore it seems logical to conclude that modern fixed pixel displays process 60i input to produce 60p display, and 60i video does in fact give better motion handling than 30p. If anyone can prove me wrong, please do. :)

Bob, you nailed it! Can you imagine the return rate for camcorder manufacturers if their cams only offered 24p or 30p? People would be screaming about "why is my little Johnny stuttering when he runs...that's not the way he runs!"

The entire attraction of 24p and 30p in video totally eludes me. The video should not call the viewer's attention to the flaws, but rather the subject material.

There is some conflicting info in this thread about how fixed pixel displays handle interlaced video. A few users said that 60i is deinterlaced to 30p. Others say that video recorded in 60i gives smoother motion than 30p. Both of these assertions can not both be true.

I have not been able to find any definitive references on the subject, but let's look at it logically. Assume that we have a native 60i video source and a modern fixed pixel display. If the 60i input stream was simply deinterlaced to 30p, then half of the motion resolution of the original 60i source would be lost! A better approach would be to use intelligent processing (deinterlacing, interpolation, etc.) to generate 60p, thereby retaining the full motion resolution. This would explain why some people perceive 60i to give smoother motion than 30p, and also why the camera manufacturers continue to use 1080/60i as their primary recording mode. If 60i was reduced to 30p on playback, there would be no reason to record in 60i.

Therefore it seems logical to conclude that modern fixed pixel displays process 60i input to produce 60p display, and 60i video does in fact give better motion handling than 30p. If anyone can prove me wrong, please do. :)

I also wasn't able to find any truly definitive source of information, but I did find these two pages (among some others as well), that have some info that relates to this:

http://en.wikipedia.org/wiki/1080i

http://hometheater.about.com/od/televisionbasics/qt/1080ivs1080p.htm

These pages, and others, imply that 1080i is always deinterlaced when displayed on a progressive display. If it wasn't, jaggies would be visible since on a progressive display all 1080 lines are refreshed progressively.

It's hard to tell for sure, but what I read from these and other pages is that after deinterlacing, many TVs then just display the same deinterlaced frame twice in a row, resulting in a screen refresh of 60Hz, but effectively still just 30 fps in terms of the video motion. Ostensibly, this is called 2:2 pulldown.

I assume it is possible, however, that some TVs do more complex processing, such as interpolating frames to try to get closer to true 60Hz (or even 120Hz) motion. Such interpolation would be fairly complex, however, as it would have to involve motion detection in order to get a good quality interpolated frame (just doing static interpolation would not look very good). Some expensive TV's may do this, but I doubt all TVs do, especially cheaper ones probably just use 2:2 pulldown.

If somebody knows of a definitive source of information on which TVs, if any, do motion interpolation, that would be really nice.

Therefore it seems logical to conclude that modern fixed pixel displays process 60i input to produce 60p display, and 60i video does in fact give better motion handling than 30p. If anyone can prove me wrong, please do. :)

You're right in the first part, but wrong on the second. Fixed pixel displays operate at 60Hz in this country. When they are fed an interlaced stream, they must de-interlace it and refresh the display at 60Hz. The problem with 30P is what is the output result of that de-interlacing. From all of the research that I've conducted on this topic, there are only a few video processing chipsets available that ignore any interlace flags with 30P video and instead properly process the stream. And by properly process, I mean detect lack of interframe motion, employ weave de-interlace process to perfectly reconstruct the original progressive frame, and then frame double to hit 60Hz refresh rate. When 30P is properly processed, it will recreate the original 30fps of video. When 60i is properly processed, it will yield the original 30 fps of video as best as is possible while minimizing any interlaced artifacts present because the two fields comprising that frame were captured 1/60 sec apart (1/50 sec in PAL). The progressive display (or output device) then frame doubles both streams to hit 60Hz refresh rate.

I have not come across ANY progressive television that is capable of doing this. I have not come across ANY AVR that will do this either. And there have only been one or two BD players EVER MADE that can do this. So everyone who complains about 30P has never seen it processed on the same level playing field (i.e., correctly processed) as 60i.

The only way you can say that 60i yields better motion handling than 30P is if your display chain properly de-interlaces 60i while it does not properly de-interlace 30P.


I'm going to edit this because the marketplace has changed since I last reviewed this issue.

http://www.hqv.com/products.cfm

This is a decent link that shows some of the products that are using the Reon chipset that has been credited with properly de-interlacing 30P video in the past. I suppose the implementation of that technology could still be questioned however. Also, ABT is set to release an HD version of their venerable SD de-interlacing chipset (the one used in that stellar Oppo SD DVD player) that is slated to be even better than the Reon. We shall see in a few months I suppose.

I also fired off an email to HQV asking for some clarification. If I get a response, I'll add it here...

I have not come across ANY progressive television that is capable of doing this. I have not come across ANY AVR that will do this either. And there have only been one or two BD players EVER MADE that can do this. So everyone who complains about 30P has never seen it processed on the same level playing field (i.e., correctly processed) as 60i.

The way you describe things, I assume that 30P is normally sent to the TV as 30PsF, not true 30P. If that's the case, it's amazing to me that almost all TV's are too dumb to detect the lack of inter-field motion and just use weave. This actually sounds like a bad time to buy a TV and there might be a lot more good choices in a year or so.

Assuming you have software that lets you force the deinterlace method to weave (or has smarter deinterlacing), perhaps one workaround would be to use a PC for displaying 30F video to the TV, essentially just using the TV as a 60Hz monitor and letting the PC do the deinterlacing.

Therefore it seems logical to conclude that modern fixed pixel displays process 60i input to produce 60p display, and 60i video does in fact give better motion handling than 30p. If anyone can prove me wrong, please do. :)But 2 interlaced fields equal 1 frame. Both HD and HDV 1080-60i NTSC run at 29.97 fps, same as standard definition. You can dienterlace 60i to 60p but with a hit in resolution because they are not full frames (Not true 60p). So 60i is really 59.94i or 29.97 fps....which is saying to me it's closer to 30p.....not 60p (a sort of psuedo 60p maybe....but not true).

In terms of frame rate for smooth motion 60i is closer to 60p. The camera is taking 60 pictures a second but only sending out odd or even scan lines for each of these pictures. In an interlaced world the CRT phosphors and our brains filled in the detail to emulate 60 frames a second. For me the frame rate is more important. I want smooth motion. Modern electronics should be able to emulate this interlace effect through interpolation and display a true progressive, smooth image. 24p and 30p cannot generate this smoothness there just aren't enough frames.

Ron Evans

The way you describe things, I assume that 30P is normally sent to the TV as 30PsF, not true 30P.

Thanks Dave for clearing up some of my absent-minded rantings. Yes, when I am talking about 30P, I am referring to 30P delivered via 60i stream. Due to the extreme shortsightedness of the BDA and the obvious irrelevance of HD-DVD (now), we are left with 1080/30P being flagged and delivered as 1080/60i. Also, I don't know of any consumer encoder that will allow us to encode 30P as truly 1080/30P (even though it must be flagged as 1080/60i per BDA spec). It can be done, however, as many HD music DVD's are now being encoded as 1080/30P even if they have to be flagged as 60i.

As I mentioned earlier in this thread, I find it interesting that ATSC includes 1080/30P as a valid broadcast format. Now that I think about it again, though, I don't think any of the progressive displays in use today would have any problems at all correctly displaying 1080/30P as 1080/60P (by frame doubling) because it would be a progressive broadcast signal not requiring any de-interlacing. The set would simply receive a full frame and then flash it twice to hit its 60Hz refresh rate.

Ron, that's not how interlaced fields are de-interlaced by progressive sets. The set buffers field A while waiting for field B comprising frame 1. The video processor then combines fields A+B and processes the resultant frame 1 and tries to mitigate the damage through various de-interlacing algorithms. This yields 30fps, NOT 60fps. The video processor then flashes frame 1 twice to hit 60Hz refresh rate of today's progressive sets. No where does the video processing chipset attempt to interpolate the even scan lines missing from field A, nor the odd scan lines missing from field B. It combines these two fields and may interpolate or apply motion adaptive technology in order to eradicate the inherent interlaced artifacts present from interlaced capture during acquisition.

Assuming correct video processing of 1080/30P, the only difference between 30P and 60i is the fact that the entire frame was captured at the same moment in time, thus eliminating the interlaced problems associated with 60i. Both formats yield exactly 30 frames per second on a progressive display.

As I mentioned earlier in this thread, I find it interesting that ATSC includes 1080/30P as a valid broadcast format. Now that I think about it again, though, I don't think any of the progressive displays in use today would have any problems at all correctly displaying 1080/30P as 1080/60P (by frame doubling) because it would be a progressive broadcast signal not requiring any de-interlacing. The set would simply receive a full frame and then flash it twice to hit its 60Hz refresh rate.

I think I'm still a little confused. So, if the ATSC standard includes true 1080/30P, does that mean that most TV's can understand and display true 30P (as opposed to 30P in 60i)? If so, then one would just need to re-encode one's camcorders 30PsF output as true 30P - is it not true that some encoders, like x264, can do that? But then I guess the only way to deliver it to the TV would be via a PC since blue-ray players will apparently re-convert it back to 30PsF..??..

What a mess. At first I was happy that Blu-ray won the format war because of the larger disk capacity, but now I think it might have been better the other way.

Aaron I understand what you are saying which is why I still prefer the interlace display. 60i is a lot smoother than 30p it effectively has twice the frame rate on an interlace display. I was just hoping that one day the electronics will be able to emulate what one actually sees from an interlace display on a progressive display. Yes interpolate the missing lines. I still prefer the image from my JVC iART CRT to the image on my Panasonic Plasma. There is more detail in the Panasonic but the motion is nowhere near as smooth as on the CRT and the upscaling of SD from cable is awful. This is not just the Panasonic its true of every set I have looked at so far. In choosing the Panasonic it was the best of the 16x9 sets I was prepared to pay for and it is not as good as the Sony HiScan CRT!!!! I would like the smoothness of interlace and high definition. Just hope that sometime soon the technology will give me what I want. Clearly I am more disturbed by motion artifacts than I am about interlace artifacts!!!!

Ron Evans

yeah Dave, you've got it right. Yes, those of us without a broadcast station at our fingertips, LOL!, must distribute HD video via BD. And that means 30P in 60i.

And Ron, I agree 100%. Interlaced video displayed on an interlaced set is great because you're talking the native language of the display. When you try to de-interlace for progressive displays, you're manipulating the original interlace stream in a manner in which it was not originally intended to be manipulated. So now you have to create a bunch of voodoo magic to try to make it all work with modern displays. My whole point in this thread is simply to say drop interlacing because we're not using interlaced displays any longer. They're dead. Let's move on to the native language of the displays we're using today, and of course that's progressive.

As the MIT expert pointed out in his little blurb I linked to in the HV20/30 forum, there is not one single advantage to using 1080/60i over 1080/30P when the target display is progressive. And actually, there is LESS of an advantage because motion between the two fields makes it more difficult for the compression algorithm vis-a-vis a progressively acquired frame.

I agree to move to progressive but in that case it should be 60p to match the display completely and get nice smooth motion. Maybe JVC / Panasonic were correct in going with 1280x720P60. Do the displays correctly up scale this to 1920x1080P60 its a 1.5 multiple?
Ron Evans

Again, agree 100% Ron. That's the best we've got for progressive displays and motion fluidity. But, anyone who's happy with 1080/60i on progressive displays and motion potrayal would also be happy with 1080/30P as long as the display chain properly processed 30P - either properly de-interlacing and frame doubling if delivered via 60i, or simply frame doubling if delivered via ATSC broadcast. And yes, your 1080P sets will scale 720P to 1080P. Of course, you're not getting a true 1920x1080 source frame. But the scaling technology today is pretty good. And there is plenty of competition among chipset manufacturers to insure technology continues to improve in both de-interlacing and scaling.

I understand you're not happy with 60i on a progressive set, so the above 60i vs. 30P doesn't apply to you.

Last week I shot some footage with my HF10 in 60i, 30p and 24p mode. here is a comparison that should give you an idea how the frame rates compare:

60i:
http://www.vimeo.com/960647

30p:
http://www.vimeo.com/960652

24p:
http://www.vimeo.com/960659

The clips are very short, so better loop them.

yeah Dave, you've got it right. Yes, those of us without a broadcast station at our fingertips, LOL!, must distribute HD video via BD. And that means 30P in 60i.

Due to the large number of existing TV's that don't handle 30P in 60i properly, it sounds like maybe there's a market for a small box that can detect 30P in 60i, deinterlace it correctly (basically just weave), frame double and output the resulting 60P to the TV. Does any such device exist?

Last week I shot some footage with my HF10 in 60i, 30p and 24p mode. here is a comparison that should give you an idea how the frame rates compare:

60i:
http://www.vimeo.com/960647

30p:
http://www.vimeo.com/960652

24p:
http://www.vimeo.com/960659

The clips are very short, so better loop them.

60i thank you. :)

Does any such device exist?

According to that link I provided to HQV's website, the Reon chipset is being used in AVR's and displays, not just BD players. I have not yet received a response to my email inquiry, so I'll send it off again. Basically, I asked them if merely including that chipset in one of the video playback components (BD player, AVR, and display) guarantees proper 30P de-interlacing regardless of the implementation. I'll also send off the same question to Anchor Bay since they will soon be releasing a new HD de-interlacing chipset.

It will be interesting reading the responses from these manufacturers.

Last week I shot some footage with my HF10 in 60i, 30p and 24p mode. here is a comparison that should give you an idea how the frame rates compare:

There are too many unknowns in this comparison. First, did you IVTC the 24PF in order to remove pulldown and edit on a 24P timeline and author a true 24P file? Second, what was your de-interlacer set at in your NLE for the 30P? (anything other than weave is wrong) Third, exactly how did you encode a 30P file out of your NLE? (I know of no other way than to deliver it via 1080/60I, in which case either Vimeo's de-interlacer in the software player or your progressive display must weave and frame double - highly doubt either is capable of doing that). For that matter, exactly what is the frame rate used in Vimeo. I thought it was 15 fps?

Aaron, I mean no disrespect but you haven't provided any sources to back up your assertion that fixed pixel displays produce 30fps output from 60i input streams. I can't prove you incorrect either, but intuitively what you said doesn't seem to add up. How can the following points be explained?

- If displays process 60i as you describe, then half of the motion resolution would just be thrown away for video content that was actually recorded in 60i. I don't know about anyone else, but when I replaced my CRT display with a fixed pixel display, I did not notice any loss of motion smoothness. I would think that a reduction by half would be noticeable.

- The latest camcorders continue to record in 60i as their default mode, even if capable of 30p recording. Canon does not market 30p as being equivalent or better than 60i when played back on a "good" display. We know that recording in 30p eliminates deinterlacing artifacts, so why would anyone want to record in 60i unless it provided some benefit in terms of motion resolution? You could argue that this is because there are so many displays that don't handle 30p 2:2 properly, but still I would think that if ANY displays existed on which 30p was flat out better than 60i, then Canon would market that fact.

- Our buddy Ken Ross is an experienced video enthusiast who has tested both raw 30p and 60i video footage on a Kuro, which is one of the best displays available. He has clearly said that 60i video looks smoother to him.

- The article below notes that some crummy displays simply interpolate each individual field to form a full frame. This results in poor spatial resolution, but the full motion resolution of the 60i input stream is preserved. If crummy displays can retain full motion resolution, I find it hard to believe that good displays would not do likewise. I have not seen any articles that say motion resolution has to be sacrificed to get full spatial resolution.
http://www.hometheatermag.com/hookmeup/1107hook2/

- This is pure speculation on my part, but if a good display can properly deinterlace field pairs within a frame, wouldn't it be possible to likewise deinterlace fields from adjacent frames?
For example:
Input frame 1 field A + input frame 1 field B = Output frame 1
Input frame 1 field B + input frame 2 field A = Output frame 2
Input frame 2 field A + input frame 2 field B = Output frame 3
Input frame 2 field B + input frame 3 field A = Output frame 4
...
This approach would in theory yield 60 unique output frames per sec on the display. It doesn't seem fundamentally different or more difficult than only deinterlacing intra-frame field pairs, other than requiring more processing power because more deinterlacing is being done.

- The article below notes that some crummy displays simply interpolate each individual field to form a full frame. This results in poor spatial resolution, but the full motion resolution of the 60i input stream is preserved. If crummy displays can retain full motion resolution, I find it hard to believe that good displays would not do likewise. I have not seen any articles that say motion resolution has to be sacrificed to get full spatial resolution.
http://www.hometheatermag.com/hookmeup/1107hook2/


Bob, It's really a shame that it's so hard to find definitive information about this, I also find it frustrating, but from the article you reference:

"The TV then has to combine these two fields into one frame to display on the screen. Done correctly, you'll see white and black alternating lines. Done incorrectly, you'll see a flashing box that flashes between solid black and solid white."

This is inconclusive because the first sentence seems to be saying what Aaron and I have been saying - that the two fields are combined into one single frame, but the second sentence seems to indicate that some TV's line-double each field and display them as individual frames. He is saying both things at the same time.

Here is another article that I referenced earlier in the thread that seems to indicate that many if not most TV's de-interlace the two fields into a single frame and then just display the same frame twice (2:2):

http://hometheater.about.com/od/tele...80ivs1080p.htm

To deinterlace a 60i frame into two true 60P frames would require a deinterlacer that could do motion interpolation. This is complex and requires buffering many frames, it is essentially what an MPEG encoder does. This would be the only high quality way to generate 60 *full resolution* progressive frames where there were only 30 originally, I just don't know if any TV's actually do this, but maybe some do.

Third, exactly how did you encode a 30P file out of your NLE?

Aaron, I think there are many encoders that can generate 30P files. For example x264 can generate progressive 30P AVC files. I believe there are MPEG2 encoders that can do it as well.

The real problem is the delivery, which you do mention. It will be interesting to see what you hear from the chip set vendors, but it seems for now the only way of delivering 30P to a TV without first going through 30PsF is to use a PC (i.e., have the PC use the TV as a 60Hz monitor).

Aaron, I mean no disrespect but you haven't provided any sources to back up your assertion that fixed pixel displays produce 30fps output from 60i input streams. I can't prove you incorrect either, but intuitively what you said doesn't seem to add up. How can the following points be explained?

http://www.hqv.com/technology/index1/deinterlacing.cfm?CFID=&CFTOKEN=16476801

This is a good read on the subject of de-interlacing by HQV, one of the leading vendors of video processing technology. As you say, you don't believe half of the vert rez is missing from interlaced video while displayed on your progressive set, which means perhaps this blurb is a bit dated, since no one seems to be using non-motion adaptive de-interlacing any longer in these displays or BD players.

- If displays process 60i as you describe, then half of the motion resolution would just be thrown away for video content that was actually recorded in 60i. I don't know about anyone else, but when I replaced my CRT display with a fixed pixel display, I did not notice any loss of motion smoothness. I would think that a reduction by half would be noticeable.

On the contrary. Motion resolution compared to what? Interlaced CRTs? I don't like the term applied to fixed pixel displays because you have ONE resolution - the native rez of the screen. And that's all you've got. Proper de-interlacing attempts to minimize motion artifacts that are created when the two fields are recombined to display as a full frame on a progressive display, yielding back the original 30 fps. Again, read the HQV blurb...

- The latest camcorders continue to record in 60i as their default mode, even if capable of 30p recording. Canon does not market 30p as being equivalent or better than 60i when played back on a "good" display. We know that recording in 30p eliminates deinterlacing artifacts, so why would anyone want to record in 60i unless it provided some benefit in terms of motion resolution? You could argue that this is because there are so many displays that don't handle 30p 2:2 properly, but still I would think that if ANY displays existed on which 30p was flat out better than 60i, then Canon would market that fact.

30P is flat out better in all things except compatibility when compared to 60i and viewing on progressive displays. This is factual and not even debatable. Due to the compatibility issues that I and many other professional reviewers have raised, manufacturers are clearly sticking with outdated technology rooted in NTSC. 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 you capture progressively, you don't have to deal with this de-interlacing mess and trying to minimize the problems you get when recombining the fields. It all just goes away, LOL.

- Our buddy Ken Ross is an experienced video enthusiast who has tested both raw 30p and 60i video footage on a Kuro, which is one of the best displays available. He has clearly said that 60i video looks smoother to him.
I would bet money that his Kuro cannot properly de-interlace 30P in 60i video. And by properly, I mean (1) detect lack of interframe movement within the two fields comprising that frame and necessarily employ a weave de-interlace process, and (2) frame double the original 30 fps to match 60 cycles per sec of the display.

- The article below notes that some crummy displays simply interpolate each individual field to form a full frame. This results in poor spatial resolution, but the full motion resolution of the 60i input stream is preserved. If crummy displays can retain full motion resolution, I find it hard to believe that good displays would not do likewise. I have not seen any articles that say motion resolution has to be sacrificed to get full spatial resolution.
http://www.hometheatermag.com/hookmeup/1107hook2/


IMO, this occurs when the video processor "gives up" on properly de-interlacing interlaced fields and is certainly NOT desireable. If that is "success" in your book, then you may as well stick with 720/60P and get real HD video.

- This is pure speculation on my part, but if a good display can properly deinterlace field pairs within a frame, wouldn't it be possible to likewise deinterlace fields from adjacent frames?
For example:
Input frame 1 field A + input frame 1 field B = Output frame 1
Input frame 1 field B + input frame 2 field A = Output frame 2
Input frame 2 field A + input frame 2 field B = Output frame 3
Input frame 2 field B + input frame 3 field A = Output frame 4
...
This approach would in theory yield 60 unique output frames per sec on the display. It doesn't seem fundamentally different or more difficult than only deinterlacing intra-frame field pairs, other than requiring more processing power because more deinterlacing is being done.

Again, then you're technically not trying to combine fields comprising the original frame as captured by the video camera. You're trying to fabricate a frame that did not exist ala 3:2 pulldown (the problems of which have been identified for years and thus the whole reason for removing pulldown while editing 24P video, rendering out to true 24P BD, and then buying electronics that will pass ONLY 24 fps to the display at which point the display then frame doubles, triples, quadruples, or quintuples that original video or film frame in order to provide a better viewing experience.

Aaron, I think there are many encoders that can generate 30P files. For example x264 can generate progressive 30P AVC files. I believe there are MPEG2 encoders that can do it as well.

I'm using Vegas Pro and have not been able to figure out how to do it without rendering to a 1080/60i template. But I'm sure you're right, although I'm not sure of their relevance for HD distribution since all we have at this point is BD.

This is a good read on the subject of de-interlacing by HQV, one of the leading vendors of video processing technology. As you say, you don't believe half of the vert rez is missing from interlaced video while displayed on your progressive set, which means perhaps this blurb is a bit dated, since no one seems to be using non-motion adaptive de-interlacing any longer in these displays or BD players.

Please, let's put this to rest, half of the resolution is NOT thrown out. Gary Merson's testing on many fixed pixel displays proved that beyond a shadow of a doubt. My eyes prove that beyond a shadow of a doubt. His testing on Pioneer plasmas showed them to deinterlace perfectly (as well as other brands) with none of the resolution thrown out. Let's understand this is 2008 and the processing is a whole lot different than it was just a few years ago. An article written almost a year ago is just about hopelessly out of date by now.

As to your preference for 30p, so be it, that's why we have choices. For me, 60i provides significantly more of the 'you are there' look. I could care less about trying to imitate the look of film...no consumer video camera can do it even near-convincingly. If I want the look of film, I'll buy a film camera. Videocameras do best what they were designed to do, shoot video that looks like video.

Now, if you believe that 30p looks better than anything else on a CRT, so be it. But to me watching a 32" display is not exactly cinematic. It strikes me as very very ironic that the same people who are obviously striving for a cinematic 'look' can only achieve that 'look' on a relatively tiny screen. Not exactly cinematic now is it? But hey, that's just MO. :)

To be more accurate in my last post, I should have used the term "termporal resolution" rather than "motion resolution".

I'll let this rest for now, but in my mind there is still a lot of uncertainty.

For those with camcorders which only record in 1080i, this whole discussion is academic. Shoot in 1080i and just be happy. :)

For those with camcorders that also record in 30p, it seems prudent to follow Ken's example and do A/B comparisons of 60i and 30p with your camcorder and your display and see what looks better to you. That's what I plan to do.

Thanks guys.

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/hdhdv/depth/hd_de_interlacing_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.

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.

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.

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?

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).

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?

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.

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.

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.

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.

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.

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.

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.

^^^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.

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.

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.

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.

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

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.