View Full Version : Question regarding AVCHD's kind of 24p
Eugenia Loli-Queru September 24th, 2007, 03:55 PM I was reading at the AVCHD site their specs:
http://www.avchd-info.org/format/index.html
and I saw that they have a 24p standard among their formats.
However, my question is this: is their 24p standard a REAL 24p (all frames being progressive), or it's like Canon's 24f format (3 progressive, 2 interlaced)? You see, while Canon implemented AVCHD on some of their camcorders, they still use that bastardized 24f-inside-a-60i-stream format instead of real 24p.
Note from Admin: The above is incorrect -- this is NOT how
Canon works! See the clarification by Barry Green (http://www.dvinfo.net/conf/showpost.php?p=749884&postcount=6) below
So this begs the question: what does the AVCHD standard actually say about 24p?
Mike Oveson September 25th, 2007, 08:27 AM I can't speak of an expert on AVCHD as I'm not one, but 24p that is recorded on DV is also recorded inside a 60i stream, even when it is TRUE 24p (such as with the DVX100 or XL-2). It has to go through the pulldown process to get the actual true frames, but that doesn't mean it isn't true 24p. I'd suspect that the AVCHD standard does have true 24p, even if there is pulldown involved. The frames are still individual frames, it's just a matter of how they are packaged within the stream.
Eugenia Loli-Queru September 25th, 2007, 11:40 AM But that's my point. I want to know if it is the kind of 24p that does not require pulldown. I don't see WHY it should require pulldown and not save it as true 24p. I mean, AVCHD usually writes its files on an HDD, so it has not the limitations of DV tapes and surrounded standards. I just don't see why that should not be true 24p without extra frames.
Douglas Spotted Eagle September 25th, 2007, 01:01 PM Because native 24p is not a consumer-friendly shooting nor editing format.
Consumers that _do_ choose to shoot 24p most likely won't have a clue what to do with it, and even if they do, they likely won't have an NLE that supports it.
It's a consumer cam, ergo; consumer features.
Eugenia Loli-Queru September 25th, 2007, 02:19 PM Douglas, thanks for the reply (I bought your Vegas 6 book btw, thanks for writing it).
However, what you say for the specific thing is not really what's going on. I mean, it's the standards that will have to push NLEs to support 24p. For example, once upon a time NLEs didn't support HD. Now they do. It is in fact more work to add pulldown support on an NLE rather than add IVTC timeline support. I mean, from the engineering point of view, that would be just bad...
Barry Green September 25th, 2007, 04:40 PM or it's like Canon's 24f format (3 progressive, 2 interlaced)?
Canon's 24F is not like that. Canon's 24F is true 24 frame recording with no pulldown and no interlacing. It's only available on the XHA1, XLH1, and XHG1.
Canon's 24P mode records the way you described: using 3:2 pulldown.
So this begs the question: what does the AVCHD standard actually say about 24p?
It is my understanding that it is genuine 24 fps, and only 24fps, with no pulldown.
Eugenia Loli-Queru September 25th, 2007, 05:36 PM >Canon's 24F is true 24 frame recording with no pulldown and no interlacing.
That's 24p. Why don't they just call it 24p? :P
Barry Green September 26th, 2007, 10:39 AM It's confusing, but it's the way it is.
Canon 24F = footage sourced from interlaced chips, but recorded on an HDV tape in pure progressive format.
Canon 24P = footage sourced from progressive chips, but recorded on an HDV tape or AVC-HD disc as 1080i using 2:3 pulldown.
Lawrence Bansbach September 26th, 2007, 11:40 AM So this begs the question: what does the AVCHD standard actually say about 24p?It is my understanding that it is genuine 24 fps, and only 24fps, with no pulldown.If the HG10, like the HV20, records 24p within a 60i stream, why the divergence from the AVCHD spec, which, from what I'm hearing, says 24 fps should be recorded as such, not as 2:3? I guess, from a practical point of view, Canon's decision makes sense because no consumer would be able to do anything with it otherwise.
Chris Hurd September 27th, 2007, 09:40 AM That's right, Lawrence... 24p in the Canon HG10 AVCHD camcorder is identical to 24p in the Canon HV20 HDV camcorder. If it was any different, the vast majority of consumers wouldn't be able to use it.
Barry Green September 27th, 2007, 09:58 AM If it was any different, the vast majority of consumers wouldn't be able to use it.
Why?
I mean, for HDV there was some reasoning there -- tape decks. But with AVC-HD being tapeless, compatibility is not an issue. So why would anyone not be able to use it?
David Saraceno September 27th, 2007, 10:02 AM I am also a little mystified by Chris's comments that 24p from the HG-10 would not be able to be used by a vast majority of consumers?
Is that NLE related, or some other basis?
Chris Hurd September 27th, 2007, 10:30 AM I was merely echoing Lawrence's observation:
I guess, from a practical point of view, Canon's decision makes sense because no consumer would be able to do anything with it otherwise.
And yes, it's a matter of consumer NLE compatibilty. Unless I'm missing something blatantly obvious, I didn't see any mention of *native* 24p compatibility within Ulead VideoStudio, Nero Digital or any other consumer-level PC-based editing app in the $100 price range.
Chris Hurd September 27th, 2007, 10:49 AM I am also a little mystified by Chris's comments that 24p from the HG-10 would not be able to be used by a vast majority of consumers?I did not say that. In fact I've gone out of my way to say that despite some unfortunate misinformation communicated by another source elsewhere on the web, it is indeed *identical* to the HV20.
What I said that if it was any different than what it is, it couldn't be used by a vast majority of consumers.
By the way... can someone name a currently shipping consumer-level AVCHD camcorder that records native 24p (that is, without 2:3 pulldown in a 60i stream)? Because I'm not aware of one. How about the same thing in a currently shipping consumer-level HDV camcorder? I'm not aware of that either.
If there is no such thing, then it's not a Canon-specific issue but an industry-wide issue, as to why no manufacturer yet offers it.
Eugenia Loli-Queru September 27th, 2007, 02:00 PM Chris, both Sony Vegas Movie Studio and Premiere LE support 24p (even if, unofficially). The rest consumer NLEs don't, but I would think that whoever switches his AVCHD camcorder to 24p, he knows what he's doing, and he has already bought the right $100 NLE. For the rest who use iMovie or Ulead, well, leave them in their fate. They won't care about 24p anyway.
I think it's a mistake for Canon (and whoever else) to advertise 24p and yet not giving us the real 24p. And while I do understand the HDV tape excuse, they have no excuse to do that for AVCHD camcorders. Heck, at least they could make it a option to let the user decide if he wants real 24p or 24p-in-60i (which could still be left as the default).
EDIT: I will call Canon on the phone and ask just that.
Chris Hurd September 27th, 2007, 02:09 PM That's fine; my point was that it's not just Canon's evil conspiracy but an industry wide one.
It's annoying to see fingers pointed at a particular manufacturer when *all* of them are equally guilty.
Where's the justified outrage against Sony, JVC and Panasonic? That's what I want to know.
Eugenia Loli-Queru September 27th, 2007, 03:10 PM I personally don't only point my finger just to Canon, but every company that does such things. Being a geek, and a reviewer writing for a popular tech magazine, I have a problem with all companies that cripple their products. However, I did mention Canon specifically because they particularly push 24p on their consumer cameras (more so than the other manufacturers), and also because I don't see me buying anything else than Canon as I am happy with their customer service (they fixed my broken, out of warranty, old camcorder for free just 3 months ago).
Douglas Spotted Eagle September 27th, 2007, 04:34 PM I have a problem with all companies that cripple their products..
I see having native 24p as being the crippling factor in a consumer product. If you're a tech geek who writes for magazines, then perhaps you should touch base with those who read the magazines. Consumers don't understand, and don't *want* to understand 24p. Period.
Spend time at a Best Buy, Comp USA, Circuit City (we do this on a reasonably regular basis) and interview a few folks in the camera section of the store. They don't get it, they get frustrated when you ask deep questions, and they don't give a damn about the "movie look" or anything else.
They want to shoot video that looks good. End of story for them. 24p requires special care and handling, and it irritates soccer mom/dad to even have to HEAR about anything other than "turn it on and shoot." Seriously.
IMO, Canon made a mistake putting 24p on a low-end, consumer-oriented camera. it would have been a bigger mistake putting native 24p in there, IMO.
Eugenia Loli-Queru September 27th, 2007, 05:16 PM Doug, I don't think it was a mistake. I am a consumer (ok, I am more than that, videography is my serious hobby), and I DO want 24p. But I don't want to pay $3000+ to get it though. Don't forget that the HV20 is one of the best-selling camcorders ever. It sells like hot cakes, and part of it is BECAUSE of its 24p/cinemode support. In fact, my 24p pulldown removal tutorial on my site is my most linked/read blog post ever.
Maybe I am looking for a product that is truly prosumer, rather than in a weird balance between consumer, prosumer and semi-pro. I think there is a market for it in the $1000 to $1500 range.
BTW, I did call Canon earlier, and they put a note on their "customer voice care" programme about it, that takes care of consumer feedback.
Douglas Spotted Eagle September 27th, 2007, 05:25 PM This may be so, but at the end of the day, you're the odd duck out.
I'll argue my point til hell freezes over, simply because roughly once every 6-8 weeks, or whenever I'm asked to do an article on small cams ie; CX7 et al, I'll spend time talking to consumers in stores. Fortunately for me, there is a corner in SLC where I can hit a Circuit City, Best Buy, Comp USA, Sears, RC Willey, and Ritz Camera all within a very short distance. All different markets, but one thing that is resoundingly clear when talking with folks buying these cams; they don't want it if it makes any aspect of their life different, or if they have to think.
99.99% of the AVCHD camcorders that will be sold in the sub 2K range are going to Ma & Pa Kettle. You're the odd man out. If Canon marketed to you, they'd go bankrupt. I like 24p too, whether it's native or embedded in a stream, as it's useful for some things. 24p on a palmcorder (IMO) is a waste anyway IMO, but that's another discussion.
Either way...Canon offers it and it's very kind of them. I'll wager a dozen doughnuts it comes back to bite them in the butt from a tech support/call center perspective. It'll likely be their #1 asked question "Why does my video look so jittery?" from consumers. Consider that every one of those phone calls costs them around $14.00 per call, ouch.
Michael Jouravlev September 27th, 2007, 05:29 PM I see having native 24p as being the crippling factor in a consumer product. If you're a tech geek who writes for magazines, then perhaps you should touch base with those who read the magazines. Consumers don't understand, and don't *want* to understand 24p. Period.
Spend time at a Best Buy, Comp USA, Circuit City (we do this on a reasonably regular basis) and interview a few folks in the camera section of the store. They don't get it, they get frustrated when you ask deep questions, and they don't give a damn about the "movie look" or anything else.
They want to shoot video that looks good. End of story for them. 24p requires special care and handling, and it irritates soccer mom/dad to even have to HEAR about anything other than "turn it on and shoot." Seriously.
IMO, Canon made a mistake putting 24p on a low-end, consumer-oriented camera. it would have been a bigger mistake putting native 24p in there, IMO.
Hello from a former lurker,
I myself am a computer professional and cannot fully agree with your arguments. The fact that camcorders are sold in big stores does not mean that their usage should be as easy as peeling a banana. Best Buy, Circuit City and such sell computers as well, why a camcorder should be easier to use than computer?
If all consumer wants is recording family gatherings and first "mama" and "papa" of their newborn child, then DVD camcorders (plain old DVD, not AVCHD-over-DVD) is the best fit for them. Put the disk, record, pop out, stick to DVD player, enjoy. And so they should be directed by salespeople.
An HDD-based camcorder inevitably requires computer interaction for saving, processing and storing video. Hence, HDD-based and solid-state-based camcorders are intended for slightly brighter audience. This audience watch video from YouTube and Stage6. They may even edit clips in VirtualDub (like downloading one-minute porn episodes once a day and knitting them together; whoa, a movie for free and some editing experience to boot). They will understand the idea of 24fps easier than the idea of pulldown process. A file is a file, it can have any frame rate one desires, this rate is not constrained by head rotation speed or tape speed or other mechanical issues. This is just computer data and should be treated as such. Geez.
I agree that 24fps is not consumer format, regular people do not shoot movies. But since HDD-based camcorders are just computers with a lens -- why not? 24, 30, 50, 60, as long as bandwidth, processing power and storage allows -- bring it on. And since AVCHD gathering is just like writing data to a computer drive, they should use computer-friendly formats as well, in particular all video should be progressive. Interlace must die.
Ian G. Thompson September 27th, 2007, 05:29 PM I don't think it's a mistake putting 24P on a consumer cam. I think that had a lot to do with marketing. Think about it...this kind of marketing whetted the appetite for some folks (like myself) who would eventually go up to a higher cam with more bells and whistles. But in the mean time the HV20 is much much more affordable option than a prosumer cam. Call it a consumer cam with prosumer aspirations (sort of like how the Panasonic GS400 was when it first came out).
What I do think is a mistake is when people refer to the 24p on the HV20 as not real. I often wonder if the HV20 included flags would people still make the same claim. Think about it...no one complained about the DVX, JVC etc.
Michael Jouravlev September 27th, 2007, 06:42 PM What I do think is a mistake is when people refer to the 24p on the HV20 as not real. I often wonder if the HV20 included flags would people still make the same claim. Think about it...no one complained about the DVX, JVC etc.
They did on DVX board. Although right now I am trying to recall what the reason was and I am not getting it. It was claimed that color information is being lost because two fields are coded in one logical frame during pulldown, once for every 4 frames. But DVX is DV, and DV is 4:1:1, so there IS color information for each line, so I don't get where the loss is.
On the other hand, HDV and DVD are 4:2:0, so you have color for two adjacent lines in a frame, and if you have two totally different fields, you lose color. But since DVX is not HDV I don't see why it was blamed to lose color.
In any case, for a consumer format losing color just in one frame out of four is not that bad.
Ron Evans September 27th, 2007, 08:28 PM Why anyone would want to make a nice new technology emulate something from the last century is beyond me. 24P was a limitation of the technology in the last century we don't need to do that anymore. It forces film technique to hide the flaws in the format( stuttering) shallow depth of field/contrast is use to also hide the fact that the frame rate isn't enough to hid this stuttering. A bit like buying a new car and asking that it ride like a model T Ford!!!!!
I am a 65 year old and started in film with the goal that I would one day like to film so that the result was just like being there and looking through a window. High frame rate, large depth of filed ( like our eyes) the exact opposite I know of the desire for 24P. Control of depth of field and colour for dramatic effect is possible without resorting to the low frame rate of 24P and consequent stuttering. With electronic distribution there is no need to pander to transfer to film.
Most consumers want to shoot a record of an event and view it as if they were there again. Ideally this would be in HD at high frame rate progressive. Nice sharp images with no stuttering. 720 or 1080 P60.
I am disappointed by this almost religious drive to 24P with lots of very poor quality TV images following this approach, panning and zooming do not work very well in 24P!!!!. I just hope this changes in the future.
Ron Evans
Eugenia Loli-Queru September 27th, 2007, 09:42 PM Rob, I agree with you. I am the last person who would cheer about 24p (in fact, a few months ago I got head to head against some old fashioned directors about this).
However, when I am promised something on a product, I like it to be just that and nothing that looks like that, but it's not quite. Besides, market "pressure" does not allow me to shoot anything else other than 24p for my music video clip projects (I help indie rock bands, for free).
Graham Hickling September 27th, 2007, 10:06 PM They will understand the idea of 24fps easier than the idea of pulldown process.
Thank you for making this very sensible point, Michael. The thing that makes 24fps complicated/confusing for Ma and Pa is the (currently) poor NLE support for it, not the format per se.
Douglas Spotted Eagle September 27th, 2007, 10:45 PM Thank you for making this very sensible point, Michael. The thing that makes 24fps complicated/confusing for Ma and Pa is the (currently) poor NLE support for it, not the format per se.
I strongly disagree.
Find a neighbor who knows nothing about video. Don't cloud his mind with anything, just hand him/her a camera in 24p mode and tell them to go shoot Johnny playing soccer.
I guarantee they'll come back wondering why it looks so jittery, and why it gives them a headache.
Sports, particularly youth sports, plus theme park activity, family gatherings, travel/vacation, holiday events are the prime reason people purchase camcorders. Sports, high speed rides, and vacation videos don't lend themselves very well to small format, hand-held cameras shooting 24p.
*many* tests were done by broadcasters, and it's no secret that 24p and 30p are not useful for sports outside the cinematic production world. 60p, 60i are. 24p and 30p with high action and high camera movement (unless used by knowledgeable people) simply doesn't work.
Try it for yourself. Grab a small format 24p cam, go shoot a high school football or basketball game while trying to follow the ball or one particular player while handholding the cam. It'll look terrible. If it doesn't, I'd respectfully suggest you get your eyes examined.
Ma and Pa Kettle don't want to know why it's juddered. They just know it is, and will return the camcorder PDQ.
Eugenia Loli-Queru September 27th, 2007, 11:28 PM Doug, you don't seem to get it. These people who know nothing about 24p, they will simply never switch their camera to that mode. The feature is there for those who do know about it and want the feature for cheap -- people like me. But we would prefer the feature without the extra pulldown removal work. Why is that too much to ask?
Douglas Spotted Eagle September 27th, 2007, 11:34 PM Eug,
Again I disagree. You don't seem to get it. If you write for consumer magazines, I'd think you'd be in better touch with what consumers do. I'm asking you to do exactly that. Spend a weekend, preferably in November before Thksgiving (store managers aren't too keen on people being interviewed during the holidays).
Ask consumers if they play with their cameras. Better yet, google and look at CONSUMER forums, not DVInfo.net. Look at all the hate posts about the Cineframe 24 in the FX1. From consumers. Not prosumers or pros.
Of *course* they play with the menus, and more often than not, don't know what they did to get into a menu. The feature is there. Doesn't matter if you know about it or not...Canon's phone lines will be burning up over this one due to the price.
Personally, I couldn't care less, because it doesn't affect me one way or the other. From a business perspective, we get calls each and every day about 24p confusion in two particular NLE systems. Even the pros don't understand how to manage it. How in the world do you expect consumers to manage it, particularly when low-cost NLE support for it is almost non-existent?
Yes, I do "get it." Part of my job is being in contact with consumers. Spend more time thinking "CES" and less time thinking "NAB" and maybe *you'll* get it too.
Eugenia Loli-Queru September 28th, 2007, 12:38 AM Look at it this way: hardware always preceded software in features. AVCHD camcorders are out, and yet most NLEs have very spotty support for it. The RED camera is out, and yet only few NLEs can deal with it directly (I think only FCP?).
Now, we get to the point where manufacturers sell 24p-capable camcorders. Eventually, NLEs *will have* to follow. It will take some time, but usually, it's how it is. Software adds full widespread support for specific new features (even if the 24p thing is just software), about 2 years after the hardware release. So, yes, I do expect all major NLEs to have 24p support eventually.
Just like widescreen NTSC DV support was spotty a few years back on NLEs too. They couldn't get the "anamorphic" bit right. But they managed.
I know what you are saying. No one wants support calls. But if they didn't want support calls, they shouldn't have put the feature there in the first place. But now that they have, all I am asking is to do it right. As I said, if they don't want consumers to play with these features, they should create a clear prosumer line for $1500. The HV20 hot sales have shown that there is market for this.
And btw. If AVCHD's standard asks for "clean" 24p on their certification program instead of 24p-in-60i, how the heck did Canon get the AVCHD logo on their cameras? Isn't there any certification going on?
Ron Evans September 28th, 2007, 06:20 AM I understand that you are being critical of manufacturers that say something is present but don't actually achieve the goal. Douglas and I are saying it's not a feature that the normal consumer wants or understands. That's why Sony puts the "EASY" button on lots of their camcorders ( that's exactly where my daughters camcorder is set all the time!!!). The consumer wants smooth motion, in focus, stabilized video that is well exposed---period. Yes consumers play with the camera when they get it. My daughter played with digital zoom and immediately switched it off!! even she recognised it as a marketing ploy that just doesn't work in a useful fashion.
As a reviewer you may spend more useful time explaining the deficiencies of 24P to the consumer and how modern technology can produce good records of the events for consumers. When to use the EASY button, when to go to manual exposure because the stupid camera makes the picture too bright in low light causing grain and encoder difficulties, when a tripod is essential for good results etc etc.
I agree with Douglas that the normal consumer does not need 24P , EVER . If you are looking for a cheap source for 24P you take what you get and deal with it. If you want the genuine article shoot film.
Ron Evans
Douglas Spotted Eagle September 28th, 2007, 08:09 AM And btw. If AVCHD's standard asks for "clean" 24p on their certification program instead of 24p-in-60i, how the heck did Canon get the AVCHD logo on their cameras? Isn't there any certification going on?
It's rare I use this kind of language, but that statement alone is absurd.
Please show me the use of the word "clean" or any other derivation of the word in this spec. (http://www.avchd-info.org/format/index.html)
Sony, Panasonic, Canon, Grass Valley, and JVC all use similar means of packaging the stream. No, there is no "certification" going on, because as far as the professional world is concerned, it's 24p. As far as the standard is concerned, it's 24p. As far as the eye is concerned, it's 24p. As far as the NLE is concerned, it becomes 24p once it's extracted from the stream.
Viewed another way; a nice shiny bicycle looks like a big flat box on Christmas morning until it's unwrapped.
Could they have made 24p without pulldown? Yup.
And dealt with NLE's that can't support it.
And dealt with displays that can't display it.
And dealt with any number of other issues.
You suggest widescreen is a similar issue, anamorphic or not. Of course it's not the same discussion. Widescreen means "gee whiz, I can shoot more of the field when Johnny kicks the soccer ball into the goal. Plus it looks more 'professional.'" More importantly, to the consumer, there is no downside to widescreen. They've been seeing widescreen for decades.
It's terrific that you've written so many articles for magazines, but it seems somewhat obvious that you're not currently in touch with the technology nor the people for whom this camera is manufactured and marketed.
Barry Green September 28th, 2007, 09:33 AM And btw. If AVCHD's standard asks for "clean" 24p on their certification program instead of 24p-in-60i, how the heck did Canon get the AVCHD logo on their cameras? Isn't there any certification going on?
You're confusing the issue here. There's nothing wrong or "uncertified" about what Canon did. They just chose one method of doing it instead of another way.
Canon implemented 24p-over-60i. No big deal, not "bad" by any stretch of the imagination, it's the same way film's been transferred to video for decades. And by choosing this method they ensured compatibility with existing NLEs. And certainly not "illegal" or "uncertifiable" under the AVC-HD standard!
But they didn't take advantage of what the format's capable of, and that's I think where your gripe is. Why waste bandwidth on duplicated fields, and having to strip out frames, and such? You do have a point.
However, what's getting lost here is in Douglas' point -- fitness for purpose. I disagree that native 24p would have added any complexity whatsoever for the consumer, because this is not a tape-based system and isn't held back in any way by needing to conform to existing decks (like HDV is; Sony kind of had to choose 24p-within-60i for their V1U because their existing decks would not support any other method). But frankly, who really cares about that measure of control and degree that native 24p would have provided? Certainly not the generic consumer, but the discriminating filmmaker. And the simple fact is: this HR10 is not produced for that customer. That's not who it's for, that's not who it's aimed at. You're trying to shoehorn a consumer product into doing the job you want done, and expressing frustration at its shortcomings. Well, sorry, but that's the way it goes when you try to press something into service for a purpose other than what it was designed.
I think you'd probably be much happier if you just waited for a proper prosumer AVC-HD camcorder to appear. Someday, sooner or later, someone will make one -- whether it's Canon updating their XHA1 line for AVC-HD, or Sony making an AVC-HD version of the V1U, or Panasonic introducing an AVC-HD follow-up to the DVX. When that happens, you'd be on very solid ground with all your complaints *if* the native 24p support of AVC-HD isn't implemented.
Until then, you're frustrated because today's offerings don't meet with what you want. Like it or not, prefer it or not, understand it or not, they simply don't. They probably meet with what the manufacturers wanted, but not what you wanted. So just recognize that these are not the products for you, make the manufacturers aware of what you want, and wait for the products you want to appear.
Lawrence Bansbach September 28th, 2007, 09:34 AM It's rare I use this kind of language, but that statement alone is absurd.
Please show me the use of the word "clean" or any other derivation of the word in this spec. (http://www.avchd-info.org/format/index.html)
Sony, Panasonic, Canon, Grass Valley, and JVC all use similar means of packaging the stream. No, there is no "certification" going on, because as far as the professional world is concerned, it's 24p. As far as the standard is concerned, it's 24p.Actually, from the AVCHD spec overview page, as far as 1080 goes, it seems that 24p must be embedded via pulldown in a 60i signal because according to the format description, "The 'AVCHD' is a brand new high definition (HD) digital video camera recorder format recording 1080i [emphasis mine] and 720p signals onto certain media by using highly efficient codec technologies." Therefore, no 1080/24pN (although the spec doesn't appear to overtly rule out 720/24pN). Sadly, as Chris pointed out, there has been a fair amount of misinformation about the spec, and I have been guilty as anyone of misunderstanding it.
As far as the NLE is concerned, it becomes 24p once it's extracted from the stream.I understand (although somewhat disagree with) your point concerning 24p on consumer cameras. But it's a shame that the spec didn't mandate that if it is included, it must be accompanied by pulldown flags. After all, why bother with true 24p if the people who could really make use of it have to jump through hoops to extract it? Fortunately, at least with the HV20, there are tools to do this. But would flags have added that much to the complexity or cost of implementation?
Could they have made 24p without pulldown? Yup.
And dealt with NLE's that can't support it.
And dealt with displays that can't display it.
And dealt with any number of other issues.That's exactly the point Chris and I were trying to make.
Barry Green September 28th, 2007, 09:42 AM Actually, from the AVCHD spec overview page, as far as 1080 goes, it seems that 24p must be embedded via pulldown in a 60i signal because according to the format description, "The 'AVCHD' is a brand new high definition (HD) digital video camera recorder format recording 1080i [emphasis mine] and 720p signals onto certain media by using highly efficient codec technologies." Therefore, no 1080/24pN (although the spec doesn't appear to overtly rule out 720/24pN). Sadly, as Chris pointed out, there has been a fair amount of misinformation about the spec, and I have been guilty as anyone of misunderstanding it.
Disagree though. It clearly says in the "video signal" section: "1080/60i, 1080/50i, 1080/24p". 24p with pulldown is not a 1080/24p video signal, that would be a 1080/60i signal. 1080/24p is a different signal. It's also a certified broadcast/transmission standard within the ATSC specification (as is 720/24p). I am quite sure that true native 1080/24p and 720/24p are part of the AVC-HD specification, without any manner of pulldown.
I understand (although somewhat disagree with) your point concerning 24p on consumer cameras. But it's a shame that the spec didn't mandate that if it is included, it must be accompanied by pulldown flags. After all, why bother with true 24p if the people who could really make use of it have to jump through hoops to extract it?
They probably didn't include mandation of flags because the format itself is designed to work without pulldown at all. That's not the way this first 24p camcorder has chosen to implement the frame rate, but you can't lay blame for that at the format's feet -- it has provision for a straight 24p recording with no pulldown.
That's exactly the point Chris and I were trying to make.
But it's not an issue though. Any ATSC-compatible television has the capability to display a 1080/24p or 720/24p signal -- it's in the ATSC spec. NTSC can't deal with it, that's true, but any monitor that meets the ATSC specifications must have the ability to work with those signals.
And NLEs already handle pulldown-less files and any necessary conversion to 60i/60p. We HVX users and DVX users and XL2 users and XHA1 users have been working with native 24p files for years -- when the Mac or Avid systems import footage from these cameras, they strip out the pulldown and leave only the 24 frames intact. The XHA1/XLH1 don't even record pulldown at all. Yet they still work with monitors and editing systems. Granted the editing systems needed to be updated, but that work's all pretty much done at this point (for handling a native 24p stream; obviously the work's not done for handling AVC-HD yet).
Michael Jouravlev September 28th, 2007, 10:11 AM You suggest widescreen is a similar issue, anamorphic or not. Of course it's not the same discussion. Widescreen means "gee whiz, I can shoot more of the field when Johnny kicks the soccer ball into the goal. Plus it looks more 'professional.'" More importantly, to the consumer, there is no downside to widescreen. They've been seeing widescreen for decades.
For many 4:3 TV owners widescreen is still a gimmick or a nuisance. They hate seeing black bars on top and bottom. They they buy an HDTV thinking they are in a happy land now, put their favorite movie in 2.35 AR and start wondering and cursing again. Because of this public HBO is castrating scope movies to fit 16:9 screen, just because consumers DON'T UNDERSTAND why they still see black bars on their widescreen TV.
There is nothing simple about widescreen in this country. The TV production has been done in 4:3 and is still largely being done in 4:3. And no one dares broadcasting widescreen sports letterboxed. The recent positive steps of airing French Open, Wimbledon and Formula One GP in WS upconverted to HD is a positive sign, these shows were shot with 4:3 center cut in mind. The center cut was aired on analog channels fullscreen, no black bars.
Where was I? The point is that only owners of widescreen TVs can appreciate widescreen. Regular public just don't care about "professional" looks of Johnny kicking the ball. Just like they don't care about 24p. 24p is out of place on a consumer cam. Sony wisely did not implement it on HC1. Even their implementation of 24p on A1U seems to be just a movie-like effect, not real 24p because it cannot be extracted into native 24p timeline (am I right?) And Sony dares calling A1U professional camera.
Douglas Spotted Eagle September 28th, 2007, 10:20 AM Regular public just don't care about "professional" looks of Johnny kicking the ball. Just like they don't care about 24p. 24p is out of place on a consumer cam. Sony wisely did not implement it on HC1. Even their implementation of 24p on A1U seems to be just a movie-like effect, not real 24p because it cannot be extracted into native 24p timeline (am I right?) And Sony dares calling A1U professional camera.
Sony doesn't market the A1u as being 24p, never have. Nor did they market the Z1 as having 24p, nor the FX1. All of these have Cineframe 24, which "feels like" 24p, but of course, is unfortunate in its implementation. In other camcorders, they've called it "cinema-mode."
The A1 is a pro camcorder by nature of its audio inputs and a few other features, but the A1 can also be a consumer camcorder when the audio module is removed. I use an A1 on a near-daily basis, and very much appreciate it for what it is.
Michael Jouravlev September 28th, 2007, 11:14 AM The A1 is a pro camcorder by nature of its audio inputs and a few other features, but the A1 can also be a consumer camcorder when the audio module is removed. I use an A1 on a near-daily basis, and very much appreciate it for what it is.
A1 has a regular 3.5 mm mic input, so it is no better in this regard than say HV20, am I right? A1 has XLR module that comes with it. If one bundles HV20 + Beachtek, will HV20 become a pro cam?
If not for Sony pushing HDV2 as the only "True HD" format and leading the HD consumer market, I would rather have HDV1. Less artifacts, same effective vertical resolution, no problems with frame grabs, deinterlacing and scaling. Both temporal resolution for Jimmy kicking the ball and spatial resolution for indies. Too bad Sony is much bigger name in a consumer world than JVC. Canon should have went with JVC, not with Sony.
Douglas Spotted Eagle September 28th, 2007, 12:19 PM <sigh> There are many responses to your post; the subject of the thread is 24p in AVCHD, can we stay with the topic if 24p?
That said, it's a 1080 world. Get used to it. Leaders of a market (or anything else in this world) usually determine what is brought to market. This is why they're referred to as "Leaders" and not "followers."
Lawrence Bansbach September 28th, 2007, 01:21 PM Disagree though. It clearly says in the "video signal" section: "1080/60i, 1080/50i, 1080/24p". 24p with pulldown is not a 1080/24p video signal, that would be a 1080/60i signal. 1080/24p is a different signal.You're right, it does say "video signal." But other than avchd-info.org's spec overview table (and press releases reproducing it) I haven't seen this distinction. However, a Sony brochure (http://www.cyberscholar.com/Sony/resources/Camcorders/AVCHD_Technology_Handbook.pdf) uses the term "picture format," which is vaguer but still applicable. Lest one might think the terms synonymous, the brochure also lists 1080/24p as an optional HDV format, which is embedded via pulldown. Sure, Sony might have used the vaguer term to compare the two standards without going into technical distinctions. But as displayed, it makes 24p under the two specs seem the same. (Admittedly in another gloss-over, the brochure also claims "While the AVCHD format can support a variety of video standards, Sony has chosen Full HD 1080, with 1440 pixels horizontal x 1080 pixels vertical." An even fuller HD format, supported by AVCHD, would have included 1,920 pixels horizontally.)
I have to return to the AVCHD consortium's own description of the spec. Why would it refer only to "recording 1080i and 720p signals" when a 1080/24p signal is clearly 1080p? It's not that I don't believe you. I just wish there were more material available about the various AVCHD formats (and how they're implemented) -- it would certainly clear the matter up and help consumers make better-informed decisions.
Eugenia Loli-Queru September 28th, 2007, 05:36 PM Chris, I *just* saw that you edited my first comment, and I must say that I am not very happy about this. While I have mixed the wordings of "24f" and "24p" in my first comment, I was talking about HV20's 3:2 pulldown, not the one found on the semi-pro cameras. My ORIGINAL question was about AVCHD and its relation to the HV20 24p (which is why I mentioned the pulldown), and why didn't Canon use true 24p for their AVCHD cameras, as the HDV format was seen as the reason before, but it's not a necessity on AVCHD anymore as it records on HDDs instead of tapes. If you must do an edit, please change the "f" to "p", not invalidate my whole post with the way it was edited. You see, I started the whole thread because I am coming from the HV20 camp. I own one, and so I am interested in going over HV20's own 24p limitations with a future AVCHD camcorder.
Thank you for the understanding.
Chris Hurd September 28th, 2007, 07:14 PM Eugenia, you will note that I most certainly did not edit your post. I didn't change one letter of what you said. I simply added to it and pointed out for the benefit of our readers that what you described there is *not* accurate, and I left a pointer to Barry Green's post which correctly summarizes the situation.
Canon's Frame mode seems to be widely misunderstood, and I could not in good conscience allow you to further obfuscate what Frame mode is... thus my link to Barry's post.
24F = 24P.
Also, the single most successful 24P camcorder in the world, the Panasonic AG-DVX100, records 24P within a 60i stream just like the Canon HV20. Nobody complains about it being "fake" either.
Mountain. Molehill.
And, invariably, you get what you pay for in this business.
Eugenia Loli-Queru September 28th, 2007, 07:28 PM For the last time: I was not talking about Canon's frame mode as found on the semi-pro cameras, but the HV20's mode (3 progressive, 2 interlaced frames in succession). I didn't try to "obfuscate" the Canon semi-pro 24f cameras, in fact, it was not my intention to include them in this discussion at all. I am interested in the $1000-$1500 market, not the $3,000-$8000 one. I maintain that my mistake was to call the HV20's 24p as 24f. But instead of fixing that, you took it the other way, that I was supposedly out to get Canon's semi-pro cameras. I wasn't. It was an honest mistake/typo.
And yes, anything that's a hassle and requires additional work to get the true 24p out of it, it's not "true" for me. I need to spend 2 hours to convert HV20's bastardized system to true 24p by exporting to a huge lossless codec before I even load it to my NLE. This is not fun. Sorry, but it's not. I hate it with all my guts. That's why I started this thread. Because I am trying to find out if AVCHD camcorders, which don't have the tape limitation, are able to, or should be able to, to record a clean 24p stream right from the beginning. I am interested in clean, out of the box solutions that don't require conversion. I want to know that when someone sells me a 24p-capable camera, if it's just that and nothing else. Why is this too much to ask?
Douglas Spotted Eagle September 28th, 2007, 09:16 PM For
And yes, anything that's a hassle and requires additional work to get the true 24p out of it, it's not "true" for me. I need to spend 2 hours to convert HV20's bastardized system to true 24p by exporting to a huge lossless codec before I even load it to my NLE. This is not fun. Sorry, but it's not. I hate it with all my guts. That's why I started this thread. Because I am trying to find out if AVCHD camcorders, which don't have the tape limitation, are able to, or should be able to, to record a clean 24p stream right from the beginning. I am interested in clean, out of the box solutions that don't require conversion. I want to know that when someone sells me a 24p-capable camera, if it's just that and nothing else. Why is this too much to ask?
Clearly you don't understand the workflow. There is no "additional work" if you have 24p in a 60i stream. None. Oops, you *may* have to set a switch in your NLE, depending on which one you use. Most of them don't require anything, they intelligently recognize the flags and present the 24p as it should be presented when imported to a 24p timeline.
In other words, it is clean, it is 24p, and it is simple to work with in post. In every professional NLE there is (as far as 24p, not every NLE supports AVCHD yet).
The problems of 24p aren't in post.
Try it rather than writing about it, and you'll immediately see how it works in practice, not theory.
Eugenia Loli-Queru September 28th, 2007, 10:00 PM I am sorry Doug, but you really don't have all the facts laid out on the table. The Canon's version of 24-in-60i in their consumer cameras is FLAGLESS. NLEs don't know that this is 24p, and if I force my project to be 24p on my NLE, then random frames are removed, not the right ones.
Only After Effects and FCP can recognize that kind of Canon HDV 24p and extract the right frames out of it *after* capture (so you still have to spend these 2 hours exporting in a lossless format when doing the pulldown removal after you capture from the 60min tape).
I am using Vegas Pro 8, just like you are (I assume). And Vegas doesn't support HV20's kind of pulldown removal. When you import that file on Vegas, it's a 60i file as far as it's concerned. If you force the project settings to IVTC, then the wrong frames are removed.
The only utility that exists that will capture *and* remove pulldown for the HV20 in one go is Cineform's NeoHDV which costs $250 (and unfortunately it's just 8-bit, for 10-bit you gotta pay $500). And all that, for no good reason, because the hardware CAN record "true" 24p, it's just that Canon decides to not save it down as such. It reminds me of Nokia not including Bluetooth A2DP profile support for all their phones, even if all their phones have Bluetooth (they just make a change during compilation to not have the feature in order to segmentize their market artificially).
Sorry, but speaking as a prosumer, this is not good enough. I have to spend either an extra $250, or an extra 2 hours each time to get the pulldown removed so my NLE can recognize it *properly* as 24p. Please do some research about what I am talking about here, especially about the HV20 because it's a big deal for HV20 prosumer owners (and even a whole forum was dedicated to this particularly, elsewhere).
Barry Green September 28th, 2007, 10:11 PM Because I am trying to find out if AVCHD camcorders, which don't have the tape limitation, are able to, or should be able to, to record a clean 24p stream right from the beginning. I am interested in clean, out of the box solutions that don't require conversion. I want to know that when someone sells me a 24p-capable camera, if it's just that and nothing else. Why is this too much to ask?
It's not too much to ask. But it's also not currently on the market. Yes the format is able to support the recording exactly the way you're asking for. But nobody has implemented that capability yet. Someday someone will, but until they do it remains an unrealized potential.
I first got into DV way back when the Sony VX1000 first came on the market. It was murder waiting and waiting and waiting for a native firewire editing card to come out (DPS Spark, anyone?) But that's what we had to do -- even though we had the camera, and the footage recorded in digital component format, we couldn't edit it until the rest of the world caught up.
Similar situation here: we have a format that's been announced, and even implemented in low-cost camcorders, which is capable of recording 1280x720x24fps or 1920x1080x24fps. But nobody has enabled that feature yet. And nobody has even announced plans as to when they might.
There is no inexpensive solution on the market that does what you're asking. The only camcorders that record only 24 frames, anywhere near your price range, are the HVX200 (in 24pN mode) and the XHA1 (in 24F mode). Outside of those, it just plain doesn't exist yet.
Douglas Spotted Eagle September 28th, 2007, 10:32 PM Eug,
I'm fairly aware of how Vegas manages 24p, and yes, I spoke to 24p in general, not the HV20. Yes, the HV20 is flagless.
That said, with this camcorder, you are not a prosumer. You are a consumer.
You might as well buy a small car with a Vortec engine in it and cry "foul" because NASCAR or ARC won't allow you to drive it in a race.
Eugenia Loli-Queru September 28th, 2007, 10:41 PM I don't think that I am going to pay $3000 for a feature that it's just a compilation option when they are compiling the firmware of their camcorders. I rather wait 3-4 years and get the feature when the manufacturers get in their right mind rather than pay money for an artificial feature that was segentized out.
Which is why I started this thread. To learn what AVCHD's standard says about the 24p implementation, to hopefully give me some hope that future consumer cameras will have the right 24p version.
Barry Green September 29th, 2007, 10:01 AM Then we've reached agreement. You will have to wait until the manufacturers offer you what you want, because today's offerings do not.
Chris Hurd September 29th, 2007, 11:35 AM I couldn't have said it better than Barry -- and when the manufacturers *do* offer you what you want, then let me know and I'll be happy to re-open this thread.
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