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4:4:4 DVX-100 or P2?


Jason Mann

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I currently own a DVX-100A and am very happy with it, but I can't help being excited by the new Panasonic HVX-200 (or P2 or whatever it's called.) A $6,000 HD camera is hard to pass up.

 

That said, I've seen the website for the Reel Stream Andromeda (http://www.reel-stream.com) which promises uncompressed 4:4:4 output from a DVX. I know this is a subjective decision, but can anyone influence me one way or the other? Isn't 4:4:4: uncompressed video actually better in some ways than DVCPro HD (which I believe is 4:2:2)?

 

What would you do if you could choose between the two?

 

And I aplogize if this is posted in the wrong forum, but it straddles the line a bit...

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Well, remember you can get 16x9 720P instead of 4x3 480P from the new Panasonic HVX200, so in most cases, that would probably trump 4:4:4 out of the DVX100, especially considering you'd have to be tied to a laptop to record that (as opposed to tied to a couple of P2 cards AND a laptop... hmmm...)

 

And odds are high that this same guy who managed to get raw data right off of the chips in the DVX100 will do the same thing for the HVX200!

 

I currently own a DVX-100A and am very happy with it, but I can't help being excited by the new Panasonic HVX-200 (or P2 or whatever it's called.) A $6,000 HD camera is hard to pass up.

 

That said, I've seen the website for the Reel Stream Andromeda (http://www.reel-stream.com) which promises uncompressed 4:4:4 output from a DVX. I know this is a subjective decision, but can anyone influence me one way or the other?  Isn't 4:4:4: uncompressed video actually better in some ways than DVCPro HD (which I believe is 4:2:2)?

 

What would you do if you could choose between the two? 

 

And I aplogize if this is posted in the wrong forum, but it straddles the line a bit...

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Isn't 4:4:4: uncompressed video actually better in some ways than DVCPro HD (which I believe is 4:2:2)?

 

No.

 

HD has more resolution than MiniDV

And that beats uncompressed SD footage anyday

 

The Sony F900 is a 3:1:1 but it's used over the Varicam which is 4:2:2

Because the F900 got more resolution than the Varicam...

 

When in doubt always go for higher resolution.

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Okay, both of you make a lot of sense, thanks.

 

So how would you rate chip size as an important factor to consider relative to resolution and color/compression? Are my DVX's chips 1/3 inch?

 

And David, good point about the possibility that Reel Stream will do this for the new camera too. They even hint on their website that one of the smaller HD cameras will be their next victim.

 

Thanks, as always for the help.

 

 

 

No.

 

HD has more resolution than MiniDV

And that beats uncompressed SD footage anyday

 

The Sony F900 is a 3:1:1 but it's used over the Varicam which is 4:2:2

Because the F900 got more resolution than the Varicam...

 

When in doubt always go for higher resolution.

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Well, remember you can get 16x9 720P instead of 4x3 480P from the new Panasonic HVX200, so in most cases, that would probably trump 4:4:4 out of the DVX100, especially considering you'd have to be tied to a laptop to record that (as opposed to tied to a couple of P2 cards AND a laptop... hmmm...)

 

And odds are high that this same guy who managed to get raw data right off of the chips in the DVX100 will do the same thing for the HVX200!

 

Hi everyone,

 

From information posted on the company website www.reel-stream.com, there is information illuding the possibility of a 720p image from a DVX100. Essentially how they are doing this is by pixel shift in both the vertical and horizontal planes for a final frame size of 1124x720, of course this is different from the actual 720p frame size.. they recommend using the Panasonic anamorphic adapter to obtain the actual frame size of 1280x720 that is considered actual 720p.

 

What is interesting to me is this is a similiar process (as I understand it, appreciate being corrected, but please don't chastise me for a misunderstanding) as the Canon XL1. The idea with the XL1's 270K 1/3" ccd's was an increase in sensitivity by about 4db. The image was pixel shifted to full resolution, but they were able to use ccd's with a reduced pixel density for better sensitivity. The converse of this method would be that color sampling is reduced to I believe 422. Of course, this is moot considering the available room on DV tape in both PAL and NTSC... well it didn't make any difference since that information would not have been used anyways.

 

So, I think they are using a similar process with the DVX to get a 720p frame, but in doing so, it is no longer 444, but 422. They haven't exactly spelled this out in any literature, and even so, a 720p 422 DVX wouldn't necessarily be any different/better than a 720p 422 HVX, except for a possible difference in the sensitivity between cameras. I realise there are many things that can be fixed in dsp and imagine Panasonic will be on the ball to have similiar sensitivity on HVX as DVX, as that is (to me) one of the cameras nicest features compared to other MiniDV handheld cameras I have used.

 

I agree with David that they could likely port the same ccd probes they're using on the DVX to other cameras and have indicated their position to explore that option. In that case, they could theoretically do the same with a 720p HVX, and probably do it at 444, based on what I have read/understood about the camera and rampent speculation about the possible ccd's it will have.

 

However, the data rate for uncompressed HD, as I understand it, is 1.5Gbps, which is totally unrealistic for any sort of field capture I would consider practical for the type of work I do. Unless you're already shooting projects in the "vipercam" class, in which case the HVX/444 mod may seem a pretty good deal.

 

So, I guess what I'm trying to say is: I've looked into this pretty deep and weighed the options. For me, I think the HVX would be a better choice... even IF they can do 720p with a DVX, it appears a mathematical impossibility to derive both 444 and 720p from this camera at the same time, it's kind of a one or the other option. That is my observation of the thing for right now.

 

brian wells

amarillo texas

student / video cameraman

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The Sony F900 is a 3:1:1 but it's used over the Varicam which is 4:2:2

Because the F900 got more resolution than the Varicam...

 

 

Hi Rik,

 

I have some information here that might be helpful as a reference tool. I am certain this has been discussed in greater detail than I could possibly comprehend elsewhere on a forum and probably years ago. So, I apologise to reprint for those who have seen this before. Not interested in stirring a ruccus, though I recognise any reasonable discussion about the technical aspects of video formats can turn that direction in a hurry. I am a student and honestly trying to sort all of this out. Thanks.

 

Original Sample Rate Before Tape

1080i & 720p Sample @ 74.25 Mhz

 

On Tape Sampling Rate

DV25 (480i)

4:1:1 13.5, 3.375, 3.375

 

DVCPRO-HD (720p & 1080i)

4:2:2 (15:7:7) 74.25, 37.125, 37.125

 

HDCAM (1080p & 1080i)

3:1:1 (17:6:6) 148.5, 37.125, 37.125

 

What I don't understand is how someone could derive from that information that the HDCAM format has less luma (Y) information than the DVCPRO-HD. It appears to me they are identical in chroma (U,V), but the HDCAM has double the information in Luma (Y).

 

Could it have something to do with the way each format records a different number of lines in 1080 (DVCPRO-HD is 1280x720 in 1080i and I think HDCAM is 1440x960, but I'm not certain) Maybe that's it. These are all just numbers and it doesn't necessarily matter which is higher, of course... Only what looks good to our eyes.. and that is subjective so I won't touch it. Any insight on this? Ive tried to study as much as I can and am in a rut.. kind of confused.

 

brian wells

amarillo texas

student / video cameraman

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Hi,

 

Actually you wouldn't have to be tied to a laptop to record 4:4:4 out of the DVX; the reel-stream device mounts underneath on the tripod boss.

 

What would be more interesting would be a similar modification to an HDV camcorder, but that's quite a big deal as it would produce significantly more data than a hard disk could handle. Almost unavoidably a tethered recorder there.

 

Phil

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Actually you wouldn't have to be tied to a laptop to record 4:4:4 out of the DVX; the reel-stream device mounts underneath on the tripod boss.

 

I'm not so sure that is correct. The Reel Stream Andromeda isn't a recorder. It's basically a USB2 output installed on the underneath side of the camera that goes into the Mac-Only proprietary software program, "Sculpter HD" and you record into a laptop or desktop over USB2.

 

They do plan a future direct-to-disc HDD version at some point and have stated it would require different hardware than what they are currently using and that the only way to record for the time being (relative since they haven't even started beta testing, that commences April 30th) is directly to a computer, over USB2, into Sculpter HD software.

 

brian wells

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From their site:

 

Do you plan to support other cameras?

Yes. It is possible that the XL2(or one of the latest HD Camcorders) will be our next supported unit.

 

(For those who don't feel like looking at the website know that it is a $3000 upgrade to your camera that will void the warranty.)

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"get raw data right off of the chips in the DVX100"

 

You can do that ? and get a 4:4:4 compression ? :lol:

NO WAY... too cool to be true...

How?

 

And about the p2 cards, I read promotioanl stuff about it, what's the catch, how much data can you store... 20 minutes of HDV? more... less ?

 

Cheerios

Thanks

 

Ben

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And about the p2 cards, I read promotioanl stuff about it, what's the catch, how much data can you store... 20 minutes of HDV? more... less ?

 

Ben

 

A 4gb P2 card will net you about 10 minutes of 720. You'll get about 3 or 4 minutes of 1080. Those are at 24 - if you're overcranking you'll obviously get less time. :-)

 

The 8gb cards are coming out at about the same time as the camera (August, I think), I believe.

 

If I end up going for it, I'll be going for three 8gb P2 cards and a laptop with a Lacie Big disk (1.6tb or so). Just too expensive to buy enough P2 cards for a real shoot, but damn - no more digitizing. :D

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A 4gb P2 card will net you about 10 minutes of 720. You'll get about 3 or 4 minutes of 1080. Those are at 24 - if you're overcranking you'll obviously get less time. :-)

 

The 8gb cards are coming out at about the same time as the camera (August, I think), I believe.

 

If I end up going for it, I'll be going for three 8gb P2 cards and a laptop with a Lacie Big disk (1.6tb or so). Just too expensive to buy enough P2 cards for a real shoot, but damn - no more digitizing.  :D

 

OMG... 4 minutes ! thats a joke !!!

How much for the 8gb? $$$

even if you get 3 X 8gb, that means you have to empty the cards every 24 minutes ? What a drag... :(

 

But we'll be able to set up a direct transfer from cam to computer right ? Like the DVX

 

thanks

Ben

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What happens with the reel stream thingy.... dyu have the computer trailing behind the cameraman ?? lol

 

I guess my real question is: Which one would be better for Greenscreen... including being able to move the camera around. alot.... DVCPRO HD with 4:2:2... or uncompressed DV resolution???.... hmmm... which one would be more cost effective too?

 

;) Im a confused adolescent...

 

Cheerios

 

Ben

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I hope you aren't asking the classic "what's the best and cheapest way of...?" question. Because you can't have both.

Ha ha

lol

I know... and you get the same answer everytime.... Cost effective doesnt mean cheap/fast/good result... its a ratio... Which is a realistic question... I think

 

Cheerios

 

Ben

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"get raw data right off of the chips in the DVX100"

 

You can do that ? and get a 4:4:4 compression ?  :lol:

NO WAY... too cool to be true...

How?

 

They install probes on the CCD's that bypass all camera-original processing. So, no white balance, no characteristic curves, nothing. What is output the USB2 port is a pre-DSP signal which can be sent to an Apple computer and recorded (@ 235Mbps, mind you) using the proprietary SculpterHD software they've designed.

 

That is how they're doing it. Because of bypassing all DSP, you have to white balance and perform all color correction in post.. But, to answer your question, that is how they're doing it.

 

I would suggest visiting the forums on their website to inquire more specifically about their product.

http://forum.reel-stream.com/

 

Hope this helps,

Brian Wells

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And about the p2 cards, I read promotioanl stuff about it, what's the catch, how much data can you store... 20 minutes of HDV? more... less ?

 

Remember Panasonic uses the DVCPro-HD 100Mbps format not the 19Mbps HDV format.. Very important distinction there. There is a simple (well kind of) method of determining how much data will fit on a card. First, understand the various implementations of DVCPro-HD.

 

In 720p60 DVCPro-HD the datarate is 100Mbps at 60 progressive frames a second. To figure out the data rate when shooting less than 60Fps, use the fraction XX/60.. So for example, 24Fps would be 24/60=0.4 or 40Mbps. Or, 40Fps would be 40/60=.67 or 67Mbps.

 

In 1080i60 DVCPro-HD the datarate is 100Mbps at 60 interlaces fields per second. You can record various common framerates (e.g. 30Fps or 24Fps) in 1080p using a pulldown similar to how 30P and 24P are integrated into the DVX100's interlaced recording format. With 1080i/p the datarate will always be 100Mbps, regardless of framerate as there is not a provision for recording anything besides 60 interlaced fields in 1080i.

 

In other words, regardless of shooting framerate, it would always lay down 60fields per second and you would remove the duplicate frames in post. Contrasted to 720p60, you CAN record only the needed frames and there is no pulldown process in post.

 

So, it would be possible to record around 20 minutes of 720p24 to an 8GB P2 card or around 8 minutes of 1080p24 to an 8GB card. The HVX200 camera will hold two P2 cards at a time.

Hope this explanation has helped.

 

There is a very passionate group of small format 24p camera operators at www.dvxuser.com and plenty of in-depth information about the HVX200 and P2.

 

Brian Wells

Edited by Brian Wells
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"In 720p60 DVCPro-HD the datarate is 100Mbps at 60 progressive frames a second. To figure out the data rate when shooting less than 60Fps, use the fraction XX/60.. "

 

 

60P ?? 60P at 100 mps.... I dont get it.. u mean 60i ?

Im just more confused

 

:huh:

 

Ben

Edited by Benny_the_kid
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60P ?? 60P at 100 mps.... I dont get it.. u mean 60i ?

Im just more confused

 

There are different kinds of HD.

720p60 is 60Fps. (Progressive Fps)

1080i60 is 60fps (Interlaced fps)

vs.

480i60 is 60fps (Interlaced fps, like a dvx100)

 

You'll probably need to research this first.. Understanding the difference between formats is the first step. There are years of discussion on the topic all over the internet, so try a Google search.

 

Trying to offer a kick start. Hope this helps.

Edited by Brian Wells
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  • 7 months later...

Webiste says supports Mini mac? How will you even really know if you've caputred the footage unless you plug it into a monitor, and forget about remote aquisition with that too - unless you're going to strap a Honda Generator to your back too. :-) What a mess....

 

So, all you need is a $3,000 laptop and $3,000 andromeda system to get pro shots. Oh, and don't forget the $2,000 35mm lens adapter. Crap, by the time you drop in $11,000 into your AG you might as well step up to PRO-HD. At least then you'd have one of those fancy Gold and Black Anton Batteries.

 

And le'ts not forget that your purchase and installation voids the warranty.

 

Andromeda says it weights 4oz and has a software application to do the recording. Sure, dev costs money, but $3,000????

 

There's no such thing as getting high-res out of standard def CCD's. Its true. Anybody who's spent any time in graphics knows you can't add pixels that aren't there in JPEGS, and you cant to it to video either. Upsampling is all it is, however they're trying to present it, and upsampling produces a lowsy image that just draws more attention to the fact that it was shot on garbage in the first place.

 

Not to say I wouldn't buy Andromeda, but it would have to be proven and at a more attractive price.

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There's no such thing as getting high-res out of standard def CCD's

Look at the picture! It looks fantastic.

http://www.reel-stream.com/magik_test.php/....tif?type(tiff)

 

upsampling produces a lowsy image that just draws more attention to the fact that it was shot on garbage in the first place.

They employ a similar type of demosaicing algorithm as the kind used by Nikon and Canon in Digital SLR's and the kind used by Arri in the D-20... The main difference is video cameras (like the DVX100) have 3 CCD's instead of a single sensor with Bayer pattern. The underlying principal is the same.

 

Oh, and before anyone gets jumpy, let me say, "happy holidays!"

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Hi,

 

Well, it depends what results you want. If you want SD, you should be able to get very good results out of a 4:4:4 camera system, notwithstanding the consumer-grade CCDs and lens. But that's not HD, and while I understand what they're trying to do with all this pixel shifting and suchlike, and it may help things look even better, I would need extraordinary evidence to support the equally extraordinary claim that they've got HD out of a DVX.

 

If you need HD, then, I'd go for the HVX. In fact, you'd probably get better looking SD results out of the HVX anyway. Downscaled HD looks extremely good. At some point, there's no substitute for pixels.

 

Phil

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