Analog
 

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_d...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.

Email
 

Laurence,

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

John

I tried sending it again.

Did you get it?

Nope
 

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

Send it to

john@interjective.com

Sorry about the hassle.

Thanks,
John

SDI interface
 

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/searc...eywords=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?

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.

sdi
 

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.