John,

The chips in the DVX are NTSC so the image will look wide unless you apply the correct NTSC 0.9 pixel aspect ratio.

Also, I know for a fact that there are some columns and maybe horizontal lines which are cropped off by the camera for the DV footage, and what's left is resized.

However, now that i think about it, even if the only difference in the green channel is some optical FOV, we should still be able to match the pixels by doing a transformation...afaik it should be close to linear. We can take samples at extreme points in the image and then adjust, shouldn't be that much more different than a resize if it is linear.

Juan, you can also buy some green paint at Lowes, I used that to paint our cyc wall and it works very well..make sure it's the most pure green they have..

Juan,

I don't think you understand what I mean. The DV clip is 720 x 480 right?... which will appear a bit wider unless you apply the 0.9 pixel aspect ratio to it. That will reshape it to something proportionate to 640 x 480 square pixel... and thus it will look normal on a monitor... But what I'm seeing is a difference between the the DV frame you uploaded (720 x 480... which has not had the 0.9 applied and is therefore a bit wider than normal, agreed) and the RAW frame (773 x 495... which has not had the 0.9 applied either AND YET is even more "stretched" wide than the DV frame.) Why wider than the DV frame?... the DV frame is stretched wide enough... applying the 0.9 pixel aspect to DV 720x480 will correct it to the normal propotion, but if the RAW frame is even more "stretched" then it needs an even lower pixel aspect than 0.9 to correct itself. Am I crazy... does anyone else understand what I'm seeing?

John

Does anybody know about this new Final Cut Pro HD? It claims 10 bit 4:2:2 uncompressed 1080p at 90-160 MBps via PCI transport . . . and from SOFTWARE alone (No additional hardware)?

I'm not sure I buy this. I will say that if it does what it claims, it would limit the 4:4:4 idea, but sure gives us enough for Hollywood level acquisition.

Somebody tell me what I'm missing here:

http://www.apple.com/finalcutpro

Don't spend a lot of time trying to light the blue/green screen setup. Just point one light at it and the subject. I know it will give harsh shadows on one side but that isn't important right now. We just need to test the side the has no shadows. Besides it would be nice to test how well the mod performs with a very bad keying setup. I assume even with bad lighting a 4:4:4 signal would be much easier to key than a DV signal would. If it was a perfect screen with perfect lighting we might not be able to tell as easily how much better the mod is. Clearly it would be better but we would get the full effect by having a badly lit setup.

If you can't get to the store you could always print out a piece of paper full of a solid 255 green image. This of course would be a huge waste of ink.

John,

Ok, here's what i see. I do understand what you are saying but I am not experiencing the same problem.

The RAW frame DOES cover a wider field than what is on the DV footage. The camera crops that off but we can see that area in the RAW footage, so right away the image is dimensionally wider. However, as for 'stretching', as long as I apply the 0.9 pixel aspect ratio on the RAW footage, it looks fine. I can especially see it on some shots of resolution charts, you can judge by the circles. The circles are ellipses without the pixel aspect ratio correction, and become circles with it applied.

What has everyone else noticed?

John,

I think i found what you are talking about..in the DVComp2, the DV version covers a slightly wider field of view, and i just noticed this...however i'm pretty sure that the camera must've been moved when i pressed the record button, it's a pretty shaky setup.

I'm going to try and take another set without movement.

Juan, is part of the 773 x 495 image being cropped or masked by the camera in order to fit the 720 x 480 DV dimensions? or is the whole thing being resized? If it's being cropped as I had assumed from previous postings, then while yes it does seem that there's a different field of view in the DV (like you accidentally moved the camera), I wouldn't say the FOV is SLIGHTLY wider. In the DV you see almost an entire plank of wood more than in the raw version. If there was even more area of the DV image that was cropped than that extra plank then that setup must have been shaky indeed... you would have had to really knock the camera in order to change the FOV that much. Anyway, those two clips are too different to compare and analyze correctly. If you could capture another two that would be great. This time hit the record button first and then start the capture. And if you can, it would be great if you could take it off letterbox mode... that would help the comparison process... I want to figure out what's going on in that Green Channel and why the DV footage doesn't seem to have it.

Thanks,
John

Will do...you're right, the only way is if i hit the zoom by mistake a bit...but we all know how touchy the zoom is when it is set to manual.

I will take another outdoor set tomorrow, and hookup the joystick so I can set the letterbox off.

I went back and took a look at that test chart you posted a couple weeks ago... very interesting.

First I scaled the image horizonally to match a 0.90 pixel aspect. And yes the circles appeared more like circles... but then I compared them to a perfect circle I created using the elipse tool while holding down shift. The circles are not perfectly round, they're a bit wider than the perfect circle I made. Of course if you've been looking at the wider version for a while then the 0.9 version certainly looks more natural, but it's still not totally propotionate.

Then I just tried resizing the 773 x 495 image to 640 x 480 (which is the size that a 720 x 480 w/pixel aspect 9.0 applied scales to.) and the circles were perrrrrrrrrfect. There's no doubt that you knocked the camera on the last comparison shots, but there's also no doubt in my mind that the raw image is more stretched out than the DV images. It actually appears that what's happening is that the camera is simply reshaping the 773 x 495 image to 720 x 480 before or durring the DV compression. So there is actually no extra part of the image we're seeing... we're just getting a higher resolution image... which is still fantastic.

Thoughts? Am I missing something? Getting somehting wrong?... I'm no expert, but this is what I'm seeing.

John

Very interesting...so it's sort of an inverse anamorphic adapter? Fits a 4:3 image into a very wide CCD? Interesting trick, probably why the DVX footage looks so sharp.

If this is correct, then it would greatly help to first up-rez the raw data and then resize to the correct aspect ratio...or even better, leave it in the original aspect ratio and interpret the correct aspect ratio at play/render time?

Juan, you definitely don't want to up-rez and then downsize to the correct AR. You always want to do all your transformations in one step. So if you're going to DV, it's best to just do one transformation to DV size. If you're going to HD, you do one transform to that size. As soon as you do two in a row, you've done two interpolations, and you'll start to see generational problems

- ben

It would actually be better I think if you not do the DV RAW capture comparisons outside like you did last time. Something there in your room is better. Something totally still and with enough detail to do indepth comparison of the channels in both DV and RAW. That outside shot was good for latitude, but if there's even the slightest bit of wind then you'll have to search tirelessly for the exact same two frames on the RAW and DV cause the tree leaves will be different... If you just shoot another Test Chart for example, you can pick any two frames of either and they should be exactly the same... that is if you don't hit the camera again ;)

John

Juan,

Can your test grab include some sort of detail very close to the right and left edges of the frame so that I can compare the FOV issue I'm seeing with the green channel. I want to compare the green channel in the RAW with the green channel of the DV.

John

juan - do you have access to the anamorphic adapter for the dvx? in these discussions about the stretched image, you said something interesting, about it being "like a reverse anamorphic adapter" - i wonder if this was done intentionally, so that when you use the panasonic anamorphic adapter, it actually matches somehow with the pixel count of the CCD? it seems like the camera was designed from the start to be used with that adapter...

perhaps if you put the anamorphic adapter on, you could have a much higher resolution anamorphic image than the dvx would give you otherwise. it might be worth borrowing (or renting) one? perhaps there's someone in your area that could loan you theirs for a test.

-benjamin

i realized i didn't finish my thought... the pixels on the CCD are square, yes? so the camera, as it processes, is squishing the image horizontally, but perhaps when you have the anamorphic adapter on, the math will work out so you take those square pixels and expand them slightly to make them rectangular ntsc pixels, and we could have a perfect 16:9 camera on top of everything else!

i don't know how to test this, mathematically, without footage shot through an anamorphic adapter though. any thoughts?

-benjamin

I agree that anamophic was build especially for the DVX, but that's more because of the 72mm diameter thread I'd think.

I'll try to figure it out... my gut says no though.

John

Juan,

I hope you can resolve the rgb registration problems.

Adding the anamorphic adapter would be a good idea if that is the ideal way to use this system (and I think it is). As I recall from the literature the Anamorphic adapter is intended to let us use "all the pixels" in the sensor rather than crop to get 16:9.
Unfortunately these adapters cost $700-$900.

HD-SDI transmitter:
Xilinx has some interesting application notes of possible interest.
an HD-SDI transmitter using the virtex II FPGA:

http://direct.xilinx.com/bvdocs/appnotes/xapp680.pdf

I think this might have some data on the HD-SDI spec.

There are a no. of relevant app notes on this site if you plan to use this part. There is also a ref. design for a SD-sdi transmitter.

I would still like to know what you are using to clip on to the altera chip? I would like to experiment with my DVX100. I would also like to try hooking up to the chip in my Sony DXC750 and DXC950 (these camera's make 700 lines resolution interlaced).

I have just finished shooting a feature with the DVX-100 with the anamorphic adapter on it. Will it help you guys at all for me to upload a clip?

Juan,

You'll find additional info on the SDI spec at:

http://www.xilinx.com/xlnx/xweb/xil_publications_index.jsp?category=Application+Notes under SDI.

Laurence,

do you have a raw frame grab as DV 720x480? That's all we'd need to see.

John

Well, you're going to have to pardon that I'm not as technically proficient as you guys are. After reading around this site for a bit, I've come to the conclusion that my version of a frame grab may or may not be what you need. When you say you need a RAW capture, I truthfully don't know if I am capable of doing that or not. I recorded the movie footage with the DVX-100 & the anamorphic adapter attached, and the camera mode in 24p advanced. The footage I have was recorded via the DVX onboard recording system (so that's what we're starting with. My method of accessing that footage is a typical dv camera (sony vx-1000) that I can either output a signal via s-vhs or of course standard 1394 small firewire. I bought a non-linear editing system back in the day (6 years ago) from matrox (MATROX DIGISUITE LE) that had s-vhs and BNC component I/O, but no firewire, as firewire was not as popular then (used that system to edit a feature with 16mm film footage transfered to beta-sp). I'm using a PYRO 1394 Drive Kit that says it transfers rates up to 400 Mbits/sec. It came with some cheesey software called SONIC DVD. So I connect the camera to the external Pyro drive via a firewire cable that I assumed was standard small firewire (Hey, but maybe since it says 400 Mbits/sec, it's actually firewire A or B whatever? - - - hope I learned something already). And then I capture with SONIC DVD software. Then maybe send you guys the file here? Is this the right direction or is this useless to you guys? Maybe I can capture with some other software that would be better? Not sure what you guys would recommend. Let me know and I'll be happy to do what I can.

Actually I didn't mean to confuse you. When I said RAW I just meant a frame of the DV as it cam off of the tape and out of the camera through firewire. I realize in a discussion like this one the word RAW can get confusing.

Anyway, when you capture to Sonic DVD is there a way to export a single frame as like a Tiff or PNG or even a JPG.

John

Hey guys,

Sorry for the short 'dissappearance' :)

I'm well on my way working on the prototype, and already have all the FPGA's and programming stuff, along with the other components. I have a design for the casing which I will probably make in my milling machine/lathe but that comes later.

I DID find a green posterboard but I left it at work today. So, i'm going to hook everthing back up and do some tests using DV tape and RAW capture of a resolution chart and maybe some other indoor shots.

I'll make sure that i don't bump the camera this time.

Also, to answer Benjamin's question, i am almost 100% that the pixels in the CCD's are NTSC, (or some other aspect ratio) but not square. This is because the RAW images clearly look stretched when viewed with square pixels on a computer.

I do not have an anamorphic adapter, and even though it is something that i've always wanted to purchase i can't really do it right now since i'm working on this project. But i guess if anyone lives somewhere in/adjacent to Indiana and wants to help that might work. :) I drive all over the state all the time anyway.

Juan

Another quick question...

About the SDI implementation, what use could it have? If you want to use it, you're going to need a computer anyway, in which case you can just plug-in a FW800 cable and watch the preview/capture with that right?

In either case, the video coming out the SDI port would not be the full RAW data.

I'm just curious if this would really be a useful feature. As for a monitor, analog S-video seems to be the best option, or do most people actually use SDI monitors???

I think analog is a better choice for a monitor.

John

I can second that. Analogue S-video monitors are much more commonly used than the ultra-expensive SDI or component monitors.

<<<-- Originally posted by Juan P. Pertierra : Another quick question...

About the SDI implementation, what use could it have? If you want to use it, you're going to need a computer anyway, in which case you can just plug-in a FW800 cable and watch the preview/capture with that right?

In either case, the video coming out the SDI port would not be the full RAW data.

I'm just curious if this would really be a useful feature. As for a monitor, analog S-video seems to be the best option, or do most people actually use SDI monitors??? -->>>

Randall Larsen's reply:

AJA makes the Kona and Kona2 cards that allow input of SDI (and HD-SDI) to the MAC. SDI is also a standard transport protocol in current TV and EFX facilities.

SDI monitors are common in high scale facilities and on high budget video shoots. The only possible objection to S-video is cable length. How long can an S-video cable be? Do we ever need to feed a video village from your mod?

I think firewire 800 is fine. I think gigabit ethernet would be even better--gigabit ethernet cards are cheap for PCs.

If you ever need to run a 300 meter cable to a computer for capture UTP Cat 5 or Cat 6 cable would be a lot cheaper than a long S-video or firewire cable.

MAC G4 and G5's already have gigabit ethernet. However, sounds like you've already committed to Firewire 800 so thats OK. Chances are there will be new parts available if you later do a mod for the new HD prosumer cameras that are coming out. I am just worried Firewire 800 won't have enough bandwidth at higher resolutions (it should be fine for the DVX100).

EBU has some standards and tech references on line. Some of these are similar to SMPTE standards that one has to pay to access. This does explain TRS and a few things FOR SDI (625) see:

http://www.ebu.ch/CMSimages/en/tec_doc_t3283_tcm6-10543.pdf

this is accessed from the tech ref home page 3000 series docs.

Juan, if we are talking about monitoring for reference only, you should have analogue out capabilities (meaning not SDI out to an SDI monitor which costs more than the DVX100). Do you have to disable the existing analogue-out on the camera or something? Why not just keep that intact? For reference only, there's no need for 4:4:4.

Nope, unless something comes up, the DVX will work completely as normal, and all outputs including the S-video on the camera will still work. I'm introducing some D/A circuitry to provide an s-video output.

If I have enough gate elements and output pins left, i might be able to implement SDI anyway, since the FPGA i'm using can handle it. The S-video is the first priority though.

I'm also thinking about making it scalable or different versions, one with Gigabit ethernet and the other with Firewire800, depending on what the buyer wants.

Juan

Yo Juan & John,

Just sent Juan an email with a file attachment that's a tiny clip of my flick shot on DVX-100 with anamorphic attachment on it. So go to it guys!!!!!! If you need something else just let me know.

<<<-- Originally posted by Juan P. Pertierra :

...If I have enough gate elements and output pins left, i might be able to implement SDI anyway, since the FPGA i'm using can handle it. The S-video is the first priority though.

I'm also thinking about making it scalable or different versions, one with Gigabit ethernet and the other with Firewire800, depending on what the buyer wants.

Juan -->>>

Reply by Randall Larsen:

Sounds great. If you also made the gigabit and firewire800 adaptors with a "camera link" or LVDS inputs you could sell to a wider market (if you wanted to).

Gigabit would probably only allow a 100 meter distance to the computer. You could use a hub to consolidate the output onto one line in multicamera shoots. Gigabit could send the whole 48 bit tif 12 bits /pixel.

There is a new high bandwidth SDI at 500+mbs but I think its only 10bit.

I think SDI coax can be cable compensated to 1000 ft.

Doremi makes a $1000 converter to convert HSDI or SDI to DVI so that low cost computer LCD screens can be used as field monitors for both HD-SDI and SD-SDI.

So there is some value in having an SDI output especially if it doesn't cost you board real estate or pin real estate that you otherwise need.

Laurence,

Can you sent it again. It didn't go through.

John

I tried sending it again.

Did you get it?

It must be the attachment size limit on my hotmail account.

Send it to

john@interjective.com

Sorry about the hassle.

Thanks,
John

Juan,

An SDI interface (10-bit) could be implemented pretty easily.
National has a one chip solution that even does HD-SDI.

See:

http://www.national.com/search/search.cgi/main?keywords=clc030

This may not handle the divide by M flavor of HDSDI, but seems to do everything else.

Of course FPGAs are nice because you can update them down the road. National also makes the chips used for "Camera Link interface" found on high end computer vision cameras.

So are you suggesting that the data be up-rezzed in the FPGA and then sent over HD-SDI?

Not necessarily. Uprezzing might be too much overhead. It would also possibly limit the options in post.

I was considering this chip the CLC30 for use with the altasens or the PanavisionSVI or the forthcoming chips from Fillfactory and National. Its a $50 part so maybe its not justified when you can make SDI in the FPGA.

Most standard def sdi is 270mbps now. However a new SMPTE
spec at 540mbp is available. I don't know whether this standard is 4:4:4 it seems from the bit rate that it must be.

The CLC30 handles the high definition so you wouldn't have to redesign the next generation.

Juan,

On the input needed for the sdi chip, it does require a color space conversion to component digital video probably best done in the Fpga unless you can tap processed video from another chip in the DVX100.

Do you know if the camera's image processor maps dead pixels and interpolates their value from their neighbors? Does it map out hot pixels and turn them off? If so you probably have to lose these features for what they are worth if you tap into raw 12 bit video.

Have you figured out how to fix the minor registration problems?

Just an update,

I've been working very hard on the prototype, and it is coming along nicely. SDI will be included for sure(unless i have trouble mass-purchasing a specific FPGA), s-video is close to being done as is the FW800 hardware driver.

Randall:
The raw images I have posted are the images as they come out of the 'dumb' A/D's. Other than the speckles, i haven't found any 'dead' pixels, and i know for sure the little in-camera circuitry that is present up to the A/D's does not do any pixel averaging.

I might be wrong, but if I am, then the hot/dead pixels should be visible in all the RAW postings i have made.

Hi Juan,

If all goes well, I'm wondering if you plan on building all these puppies yourself by hand, (because a lot of people will want one), or are you thinking about mass fabricating?

I personally can't wait to get one.

For starters, i'm planning on building them myself, but I do have other people who are going into this with me.

This is not final, but there will be a website such that you can actually monitor process on the installation, track the unit when it is sent back, etc. Test footage will also be posted as soon as the unit is installed and calibrated, so you can see results even before you get the camera back.

Some parts i might have another company make in bulk, but I will probably do the assembly. I have put a lot of effort into making it a design that can be easily assembled, and is very modular so it's easy to troubleshoot.

Juan

Juan price? do you have a ballpark yet?

Juan, you mentioned way back when that the ability to capture 4:2:2 uncompressed with any gamma changes, etc from the DVX would also be possible via this add-on. Is that still the case?


Also, a question for everyone I have as an independent filmmaker as to how pragmatic is using the 4:4:4 raw image as a method of doing long form projects. What processes would there be to go from the raw to a broadcast format? Is it time consuming to do the conversion? Also what is the gain using the raw since it will be converted to x format anyway (sort of a silly question, but still...)?

A lot of the technical talk is flying over my head and I just want to know what the functional potential is for making films.


thanks for all your hard work.

es

Eduardo,

The SDI output provides digital 10-bit 4:2:2 uncompressed video(YCbCr). The FULL quality RAW video is 4:4:4 12-bit RGB, which is what gets recorded as raw TIFF frames through the FW800 interface. There will also be the option to down-grade the quality that is recorded in the following ways:

RGB:
12-bit
10-bit
8-bit

YCbCr:
4:4:4 12/10/8bit
4:2:2 12/10/8bit
4:1:1 12/10/8bit
4:2:0 12/10/8bit

In either case, you can do all of this in post from the full quality output, but having the hardware do this simplifies the process and allows you to record longer on the same size drive.

I am contemplating the possibility of allowing the user to decide where the dynamic range will be allocated for 10/8bit selection, but that might get a bit complicated.

Juan

So the FW800 interface won't be able to capture the 4:2:2 uncompressed? I ask because The FW800 provides a cost-effective portable soloution as far as shooting on location (least I hope so). There are no SDI portable drives, right?


thanks for your prompt replies.

Yes, the FW800 interface will capture all of the settings i listed above, which are all uncompressed. In addition, the SDI will provide 4:2:2 10-bit, just because that's what the SDI standard is...but you can also get 4:2:2 in any flavor/decimation/precision via FW800.

I took one of the raw images you posted(the one of the tree) and I figured out that there are 382,635 pixels in that grab, yet the DVX100 has 410,000 pixels per CCD. Shouldn't your grabs be bigger?

That's correct, there are however some pixels which are covered up in the DVX, i think they are used to adjust the black level of the image. This is normal and is done in all cameras.

The 410k figure is correct, however a smaller portion actually 'sees' an optical image.

Juan

Hey Juan sorry to bother you but what is the statis of getting a stil(s) image of a gren/blue screen setup. I am really excited about testing out the keying with this type of footage.