|
Graeme,
thanks for all the information - really valuable - I have a question that perhaps needs a new thread - about going from progressive to interelaced... but while you're here... what about going from 720p to 1080i? The HD100 camera and deck are able to output 1080i. What are the image issues with this process? Have you converted HDV 720P to 1080i using your own products, and is there a need for a third-party product, or will the JVC conversion options be as good as it gets? thanks in advance, Nigel Anyone who has any thoughts or experience - I'd be very grateful to hear from you.... Cheers. [QUOTE=Graeme Nattress] 1080i might be flavour of the month, but progressive video will be the future king, and we won't ever go back to interlace. Interlace is just compression, and pretty poor compression compared to what can be done digitally these days. |
I must admit I've not done any 720p to 1080i conversions.
If you're doing 720p30, you'd just map frame for frame, so you'd end up with 1080p, but in a 1080i video. Because you've scaled up, you'd think that it would look soft, but 1080i has to be soft to stop interlace twitter, so in real 1080i you might have a higher horizontal rez, but in practical terms, I don't think you'll see much difference if the scaling up is of high quality. For 720p60, you'd again scale up frame for frame to get 1080p60, then compress two frames into two fields to go to 1080i60. This should look very good indeed as again, the interlace and it's necessary filtering will give the 720p room to be blown up a bit without looking bad. The only thing that's really going to improve things is scaling algorithms, and that's something I've been working on for quite a while now, as it seems that it's possible to do quite a bit better than standard and even exceptional video hardware manages. Graeme |
Actually the Multibridge wouldn't be that bad with Final Cut pro. What I plan to do for most things is actually run component in and capture directly to DVCpro HD or photo jpeg. This gets rid of the need to have massive hard drives but gives higher quality than using HDV. With photo jpeg you can get full HD resolution at 4:2:2 for around 30 MB/s which should work even on a single drive system. The Multibridge on a PC cannot capture to a compressed HD codec yet.
The other option is a Cineform Aspect system that captures directly to their cineform HD codec which would also only be around the datarate of DVCPro HD. This option costs a lot more than the decklink route but may give higher quality. For the problem of 720p 30p only We could always try to interpolate the in between frames to make a 60p for broadcast. This would only have to be done after the final edit. If a really nice tool is used that actually creates new frames nobody may even notice. It would be really hard to see an interpolated frame every other frame 60 times within a second. Even if the in between frames were blended it might be enough to fool a lot of people. Does anybody know if there are actually any broadcasts in 720p 24p? How does the pulldown work for 24p material on a 60p display device? What do 24p DVD's do on a 60p display device? |
Quote:
Quote:
|
Interlaced will be gone one day but what will replace it will be 1080p60.
After European HDTV organization decided make 720p50 standard for Europe, Sony pulled it's muscle, three things happened: The commission retracted decision. Sony started push for future 1080p50-60 HDTV, MPEG4, Part 10 based. Sony introduced superb low cost 1080i HDTV cameras. FX/Z1 supposedly sold about 150,000 units by now worldwide. If that is correect/not I don't know, but new Sony HDV cameras sell at many times rate than PD150 was when was introduced. Sony basically developed 1080i60 analog HDTV in Japan, later 1080i60 digital. They did with NHK. They very powerful in broadcast world, are able to push their technologies. They also very capable. Throughout their history they were able make better, smaller products than competition, in the past did not even care what competition is doing. Competition just gave up competing with Sony on new formats etc. When Panasonic developed M2 for broadcast, Sony just developed better format, M2 became history. I think we will see same thing in JVC HDV vs. Sony HDV. Can also see different marketing strategy compared lets say Panasonic, when their people get on these boards. Sony people are prohibited to do. They just make superb product, like XDCAM, HDCAM, Z1, let owners discuss advantages on these boards. Lately Sony were mismanaged though, their movie division prevented electronics division produce avantguard products that would harm movie business, due concern about copy protection, etc. Another advantage Sony has, make the best sensors. Have 75% of worldwide CCD market, are only company capable produce in quantity high quality CMOS with high frame rate at high pixel count, high S/N ratio. JVC normally use Matsushita CCDs, their top broadcast products use Sony CCDs. Nikon use Sony CMOS, top photography manufacturers use Sony CCDs. HDTV and FILMOUT: For broadcast 1080i has advantage because except some US 720p broadcast, is only 1080i HDTV broadcast anywhere in world, including two satellite programs in Europe. When do film transfer, optical printers are 2K. 1080p is 2K, wheras 720p is 1K. So question is, if equal quality sensors and high quality lewnses used, would 720p24 HDV or DVCPRO HD look better when transferd to 2K than 1080i HDV transferd to 2K? Digital projection in theaters - 2K. Future will be likely 4K, as new Sony projectors are 4K = about 8MP. 24p on a home screen: 1080p24 is part of HDTV spec, as far I know all 1080 broadcast is 50-60i and 24p is broadcast with pulldown. 24p does not look good on CRT, maybe not even LCD. 30p on screen has more of theater 24p feel than 24p does. In theters each frame projected twice, otherwise motion is jerky at 24, at stimulated 48 fps is better. 24 fps is rate that dates when sound film started in 1929, while video people always wanted 24p, top film directors wanted highest frame rate they could. Top 70 mm film productions were 30 fps, with 24 fps 35 mm cameras running side by side for to create 35 mm prints. IMAX HD is 48 fps. Some manufacturers catering to 24p hysteria, taking advantage of it, calling it "film look". Best film look something totally different. 24 fps and grain are negatives, not positives about film look. DVCPROHD: DVCPRO HD compressed about 7:1. It's just too compressed. PROSPECT HD: This superb 10 bit compression software now available saparately and bargain OEM price negotiateed could be with CineForm. Radek |
Radek - very interesting...
So if the standard lens on the HD100 is not much better than the Z1 lens (unknown, but likely given it's price) - and the optional wide is $12k ($16k AUD) - why would anyone shooting a run and gun doco for broadcast buy the HD100 ahead of the Z1? In other words, I can shoot 720p 25 with the JVC, but if I want the product to be broadcast today, or in the next couple of years, I'll have to convert it to some form of interlaced or other - correct? The advantage of having 24 or 25p is... archive... transfer to DVD... what? Especially in the context of sacrificing steadyshot, autofocus, known quality product in the Z1. After all, it seems the 1080i can be converted effectively to progressive in post - correct? The more I read, the more I learn, the more confused I become (in the sub 10k playground that is...) Cheers |
1080i HDV frame consists of 2 fields. Each is 1440x540 pixels. Makes total of 778,000 pixels, progressive, 25-30p. When you deinterlace properly, on still image or image with little movement, resolution will double, will be 1,555 pixels, progressive, 25p or 30p, so frame effective pixel count will vary between 778,000 and 1,555,000 pixels. Sony camera with true 1080i capability costs 1,800 USD. Sony people will not get on boards like this to defend products. Are satisfied with market share they control.
DVCPROHD consists of 960x720 pixels = 691,000 pixels. 720p HDV consists of 1280x720 = 922,000 pixels Radek |
Radek/JG/Don Quixote/Etc, I think we liked you better when you posted under your Joseph George alias -- at least then you didn't drop words out of your sentences to make it sound like you were a foreigner. Your tirades have always been a little difficult to follow, but at least they were usually proper English; now it's even more difficult to follow what you're saying. Except for the one constant: "sony good, matsushita bad" -- that part's coming in loud and clear in your posts.
------------ Nigel, the question was: why the JVC instead of the Sony? There are many differences between those two products, and for some people's circumstances one will be obviously a far superior choice than the other. For someone doing TV commercials, the JVC. For someone shooting live events, the Sony. For someone shooting for a 720p network (Fox, ESPN, ABC) the 720p JVC. For someone shooting for a 1080i network (NBC, CBS, PBS, Discovery), the 1080i Sony. If someone values the shoulder-mount form factor or the broadcast-style lens or the ability to interchange lenses, the JVC is obviously prefereable for those circumstances. But, the JVC costs more. And it doesn't shoot "live" footage. And that's a major, major drawback. For someone shooting live events or reality TV, someone who wants and needs the 60i/60p look, the JVC can't do it. There are three basic frame rates that people are discussing here, which are 24p, 30p, and 60i/p. They break down like this: 24P: JVC should be superb, Sony is an atrocious simulation 30P: JVC should be superb, Sony is half-resolution simulation. 60i/P: Sony does superbly, JVC doesn't do *at all*. So for those wanting a specific frame rate, the question should be really quite easy. Just pick which frame rate suits your shooting style (film-like, go JVC; reality-like, go Sony). Regarding overall quality of the footage, you really can't compare them directly because they don't do the same frame rates at the same sizes. 720p HDV and 1080i HDV are utterly different, but at the core they will provide about the same perceived resolution, when all is said and done. But not at the same frame rates. The JVC's 24p/25p/30p should (should) be substantially, significantly sharper than the Sony's CF24/CF25/CF30. But the JVC has no way to compare against the Sony's 50i/60i. It doesn't even try. The best it offers is "motion smoothing" on 30p, which we have yet to see, but should be about comparable to shooting 30p with a 1/30 shutter (in other words, it'll probably be blurry and nowhere near a direct simulation of 60i). But, we'll see... With the JVC, you could always change out the lens. I wouldn't be surprised if the stock lens of the JVC was not a great performer, probably comparable to the Z1's lens (not bad, but a lot of C.A.). But the JVC has the option to put on other glass, something the Sony can't do (well, at least, without a hacksaw and the help of Eidomedia, that is). BUT: the alternative lenses for the JVC are pricey pricey pricey, so I doubt fewer than 5% of HD100 users will ever get the optional lens. For super-telephoto work, the JVC wins hands-down. For shoulder-mount "looking-like-a-broadcast-shooter" concerns, the JVC wins hands-down. For actual manual control of the lens, the JVC wins. For OIS and autofocus and the programmable zoom/focus feature and all that stuff, the Sony is the clear and obvious winner. And the FX1 is much, much cheaper... the Z1 is a little cheaper ($300 retail, we'll see what street price is). Plus the Z1 is true international (does both 50i and 60i, NTSC and PAL) whereas the JVC is only partially international (does 24p/25p/30p, but only NTSC OR PAL, not both). Graeme's seen footage from the JVC on tape, and I believe he said it was the best-looking HDV footage he'd ever seen. JVC's implementation of HDV has a lot less compression than Sony's implementation, which should make it cleaner with less susceptibility to motion artifacting/macroblocking/etc. You just have to make sure that the type of shooting you intend to do with it is appropriate for the framerates it offers. For TV display, probably (and this is a wild guess) 90% of the HDTVs out there are 720p-native. JVC's making a big point of that in their marketing. There are a few 1080i TVs (mostly CRTs) and a couple of 1080p televisions, but the vast, vast majority of LCDs and plasmas and DLPs and everything else are 720p native. Plus Europe looks poised to go 720p. The US allows both standards, and so far the major sports networks have gone 720p (ABC/Fox/ESPN) and the others have chosen 1080i. In Europe it'll pretty much be 720p-only, pending the EBU's release of a final recommendation. So, in other words, there are very good reasons why someone would choose one of these cameras over the other. They both do things that the other one doesn't. You just have to determine which unique capabilities are more important to your shooting style -- after that, the choice should be easy. |
It kind of depends on what your shooting now. If you are hand holding at a wedding no matter how sturdy you are that camera will have movement in every single frame which means pretty the whole image will get deinterlaced. Unless you are shooting something like a movie where you can keep the camera perfectly still a good deinterlacer will not help you very much.
So based on that hand help or shoulder shooting might be slightly better with 720p. Another thing you have to think about also is how much rendering do you really want to do. It is nice to say we can convert and use a high quality deinterlacer but the fact is that most of us who have deadlines may not have that option. If you are talking about a few hours of raw footage for each project have fun converting. Now if you are doing small film shorts or commercials well that might be a little bit different. Another thing to think about is how many bits do you get per frame in each format. 1440x1080i gets about around the same bits as compared to a DVD encoded at 5.5555 Mb/s 1280x720 gets around a DVD encoded at 7.25 Mb/s. Depending how JVC will write 24p to HDV tape it may be even better. If they only write the 24p then you could get close to a 9Mb/s DVD which actually isn't all that bad. That is a lot better than 5.555 Mb/s considering even if you have a camera to shoot 24p 1080i that it would still be put in the same size 1080i stream like how the Z1 does it. Even if the lens on the JVC is of the same quality( I highly doubt it would be less) you may be only able to read X amount of detail anyways. If that area is at or under the 1280x720 the Z1 1080i wouldn't really have any more detail since it would get cut off at about the same level. Even with pixel shift only so much detail can come through the lens. If you shift the green chip one half of a pixel that is like having a chip with the density of 1440 sensors. If that much detail can't come through the lens the pixel shift just doesn't have the same result. I actually think the new HC1 has a tiny bit more detail than the Z1 does. If that thing had a little bit better lens we might really see the difference. I'm not really on one side or the other right now. In the next few months I will be buying 3 HD cameras along with an uncompressed HD system. I'm in no hurry so I am waiting until the other cameras come out. If the JVC had real 60p to tape this would be a lot easier. I may even get one of each since all three with have their advantages and disadvantages. Either way you look at it we kind of got screwed into a small format war again. If you are in the 720p camp it will be very hard to deal with footage from somebody in the 1080i camp. To say 24p will go away and never be seen again is kind of silly. As long as there are people out there that want to watch any movies made from the 1930's up to today there will be some kind of support to view 24p. |
Good post Barry. Really, it doesn't matter whether you shoot 720p or 1080i today, as long as it's:
a) good quality b) good quality and most importantly c) good quality because you can pretty much losslessly convert from 720p to 1080i or 1080i to 720p, and although they'll maintain their respective "look" in terms of progressive or interlaced, they'll have sufficient quality. I do think that the 720p24 HDV footage I've seen from the JVC HD100 is the best HDV footage I've seen. It looks very, very much better than the early JVC HDV cameras, and much better than the Sony cameras which although offer higher resolution, don't seem to offer any higher detail, and do tend to look rather videoy. Putting lots of pixels into a 1/3" chip is not an easy task. It puts stress on the major aspects of camera design: a) the lens, b) low noise performance, c) dynamic range, and hence all 1/3" HD cameras are going to be somewhat limited in their max picture quality, and given that, the 720p models with their larger pixels are just going to look better, and also given that they have less compression, if quality picture is what you want, they're going to be the clear winner. I think Sony are rather blinkered in their approach to video in that they don't give you proper 1080p24 or 1080p30 on their FX1 or Z1, and don't give 720p either. Similarly, I think JVC should allow 1080i recording on their cameras, but I don't think it's such a necessity as the real progressive modes that Sony are missing. Panasonic have the right idea in giving us both 720p and 1080i, and even 1080p in one camera. They are telling us to make the choice, not for it to be fixed for us. But to get into debates about the number of pixels an HD format has is ludicrous. I find that DVD's 720x480 pixels is good enough to stand up to being projected on an 80" screen. Sure, the picture could be better, but it's more than acceptable. HD looks better still through the projector, but if the screen was any smaller, I'd not be seeing the HD benefit unless I was to sit up really close. Shooting 4k HD matters for a cinema screen, but it's ludicrous to think that it matters in a typical home setting. 720p has more than enough resolution to make great looking big pictures in the home. But even worse than just looking at the number of pixels, is to ignore the quality of those pixels. I want high definition, not resolution. Resolution is easy, just stick VHS into a Terranex upscaler and you've got high resolution, but you don't have high detail or high definition. HD is high definition, so lets see some real definition!!! Graeme |
And yet once again I have to agree with Barry and Graeme.
I sometimes think SONY loves 1080i just because it sounds more impressive in a brochure. I don't think very many people could really tell the difference between the two if it was shown on a HDTV. Yes it would be nice to have 1080p but 1080i is far from 1080p. Like I said above have fun spending countless hours converting your 1080i footage into 1080p. I even question at this point if the 1080i/p on the Panasonic is going to be good enough. This is a camera with the same size chips and type of lens as all these other cheap HD cameras so how well could it even look? Now Panasonic could have taken a page from Reel stream to get some half way decent results. Look what the guys at Reel Stream did with the 720x480 chips from the DVX100A. I know I haven't seen any footage from any of the new 720p cameras but I know Graeme knows what he is talking about when it comes to image quality. I think I might be leaning towards getting a HVX200 and a HD100. They do cost a lot more together so I might have to make due with just 2 HD cameras for now. |
Quote:
|
Quote:
|
Barry, Thomas, Graeme,
Thanks for your responses - very valuable. [QUOTE=Barry Green]Radek/JG/Don Quixote/Etc, I think we liked you better when you posted under your Joseph George alias -- at least then you didn't drop words out of your sentences to make it sound like you were a foreigner. Hmmm, I've pondered over these 'Radek' posts... Cheers, Nigel |
Guys, just a friendly reminder from the management... we really can't allow this to turn into a discussion about personal feelings regarding each other. Please try to concentrate on technical issues. Thanks!
|
Quote:
If understand correctly, if CCDs and lenses are excellent, 1080i HDV may have edge over 720p HDV for film out, and for conversion to 1080p, which where is industry heading. Radek |
"ANSWER: The JVC recorded to tape will NOT be significantly sharper than CF24, CF25, for certain not when converted by DVfilm. CF24? Yes, the JVC will be significantly better, just shoot 1080i50-60, deinterlace by DVfilm or use CF25."
But as one of the few people who've actually seen HD100 720p24 footage, I can tell you it's a lot sharper than anything of a FX1 or Z1, and looks less compressed. As for "everyone is broadcasting 1080i", just think about that for a second. What are they broadcasting exactly?? For the most part it will be film sourced material, ie movies, and that's 24p embedded in 1080i with 3:2 pulldown. Sony loves 1080i because interlace is the look of drama in Japan. In the USA, 24p is the look of drama, and interlace is the look of crappy soap operas, news and current events. The point is, that 720p produces video with equal quality to 1080i (at the same frame rate) so to get any real improvement we're looking at moving to 1080p60 / 1080p50 which I don't see coming very soon. I mean, the USA can't even manage a "simple" move to digital broadcasting without mucking it up so completely that the implementers have become a laughing stock. They're fouling up a move to HD by having upmteen different standards, and they've not had the common sense to address the major failings of NTSC in the process, the utterly ludicrous 29.97fps non-integer frame rate. I wouldn't trust the FCC, ATSC, whoever, to organise a piss-up in a brewery.... Ok rant off. Sorry... Graeme |
Is clear that present 1080i is dominating HDTV broadcast and HDV, with Sony being main proponent. Future will be 1080p60. For most of us 1080p24 is enough, if 1080i60 can be pushed through 25 Mbps pipe, you be able push 1080p24 through 20 Mbps pipe, even better quality 1080p24 at 25 Mbps.
Maybe new Panasonic HVX200 will be catalyser, will make 1080p24 mainstream mode on future HDV cameras by Sony, others. If new Panasonic camera provides true 1080p24 at 80 Mbps, and 1080p30 at 100 Mbps, will be true breakthough. My opinion is we will have to wait for true 1080p for while. Sony, Matsushita need make money first by saturating market with 1080i and 720p. 1080p24 will be next step, then 1080p60, will become new HDTV standard and everyone in industry need to upgrade again. Radek |
But who has enough room in their house to do justice to a 1080p picture?? Most people don't have a TV good enough for standard def. The broadcast pipe to people's homes is so compressed (and will always be if they can broadcast two channels instead of one in the same bandwidth) that there's little point in high def anyway, if it's going to look like macroblock city....
HD is wonderful for replacing film for drama production, for movies and stuff, but to madly rush onwards when very much most people cannot even fully appreciate standard def is really ignoring the major issues facing television production today. Graeme |
Quote:
The macroblocks you refer are caused by operaters who are trying squeeze more than one channel through one channel pipe/bandwidth. Radek |
First, I've never been lucky enough to see a decent HDTV broadcast. They're all over compressed. Second, what size 1080p screen do you think would be suitable for viewing distances appropriate for a normal home? Personally, that resolution is not practical in the vast majority of homes.
Graeme |
Native resolution would be 68.8 inches (based on 32 pix per inch)
Optimally, a 60" television is what you'll want. Is that too big? I'd dispute it is. And this is only if you want to view at native. Most folks won't care/know the diff RIGHT NOW, but we're moving towards the original proposal of 60p, and getting there a heckuva lot faster than people thought we would. Just a month ago, someone commented that we'd not see 60p displays for at least another 6 years. They were only off by 5 years, 11 months. |
Wow I didn't realize the Czech Republic was the capital of the HD movement. Heck I think I should move there so I can finally watch decent HD.
Radek why are you talking about 720p like it is some nasty disease? I thought the whole point here is not what the broadcast format will be in 5 years but what kind of video can we get out of the cameras we can buy today. I personally don't really give a rats but what moronic format some dumb suit wants to throw at us in the future. I care about what the video looks like that I shoot today. Currently Graeme is the only one of us to have seen and compared footage from both of the formats. I think we can all agree that when it comes to image quality Graeme knows his stuff. If he says the 720p from the JVC looks just as good if not better than the 1080i from SONY well maybe it does. While it does kind of suck to only have 30p 720p right now, 1080p is also limited to 30p. This means in terms of motion they will look the same. It's kind of funny how people will say 720p 30p looks like garbage but then say 1080p 30p will look perfect. |
For your 60" wide TV, showing full 1080p, you have to be about 9 ft back to not see any pixels. I dare say you can actually sit a lot closer and not be bothered by pixels though.
I have to wonder, however, how many people are able to set up a screen and projector (I don't think a 60" TV set is at all practical) to get the benefit of 720p, never mind 1080p, especially given that the projector is going to be a lot futher back still. Graeme |
Quote:
Now do some of those TVs have a built in deinterlacer? I'm pretty sure I remember Samsung having one built in. I'm not too sure. If you watch 1080p footage frame by frame on your computer, you do not see any pixels. Why would you see it on a TV that is made to display that resolution? |
20/20 vision wields approximately 1/60th of a degree resolution for the human eye.
So, my 50" TV is 1280x720. The height of the TV is 24.5". Each pixel, then, is .034" tall. The viewing distance (x) ideally would be the distance at which .034" (y) is less than or equal to 1/60th of a degree of vision for me. So the calculation is: tan ( 1/60 degrees ) = .034 / x x = 117" So you want to be approximately 10 feet away from a 50" 720p screen in order to no longer be able to perceive scan lines with 20/20 vision. As it so happens, the rule of thumb for TV watching is double the screen diagonal size, which happens to yield, in this case, 100", whereas my 20/20 formula yields 117". Not bad. And 10 feet is not very far in a decent size living room. For a 10" projection screen, you want to be 20 feet away. Well, that's not so bad either, because the throw length for projectors is going to be more than that anyway, so if you can't sit 20 feet back then your room's too small anyway. Now, I'm gonna wait for 1080p projectors because I don't want o have to be 20 feet away - I wasnt to be able to sit as close as I would in a movie theater, i.e., have the screen take up more than 50% of my field of view. If we had 1080p screens, we'd be able to sit closer to the same TV, or have bigger picture sizes, without sacrificing picture quality. |
| All times are GMT -6. The time now is 11:42 PM. |
DV Info Net -- Real Names, Real People, Real Info!
1998-2025 The Digital Video Information Network