Driving HDMI/DVI moniors from the SDI-out

[Seth Larney]

Hey guys,

We have ordered the Quadro SDI daughter board for our Scratch setup (we are currently running DVI to both monitors but Audio sync issues are forcing us to go SDI).

I'd love some opinions on setting up our new the SDI pathway as
there are a few resolutions concerns that I want to make sure will
come together.

So, this will be our setup :

Quadro 5600
SDI daughter board
Left LCD (for Scratch toolset) - Dell 2408 1920x1200, DVI or HDMI
input, 8-bit
Right LCD (for Fulscreen Reference Grading) - HP Dreamcolor 24",
1920x1200, DVI, HDMI or Displayport, 10-bit
3rd LCD (on top, Client monitor, needs to be a clone on the
Dreamcolor) - sony Bravia 40", 1920x1080, HDMI

Now, my concern is with the 1920x1200 vs 1920x1080 resolution
differences between the Dreamcolor and the Bravia (because they both need to be on the SDI out and one is 10-bit and the other is 8-bit). I have already
tested and the Bravia will NOT accept a 1920x1200 signal at all.

The plan is this :

Connect the Primary DVI output of the Quadro to the Dell for the
Scratch toolset, then,
I am thinking of using the HDLink or HDLink Pro to convert the SDI
signal (WILL THE SIGNAL BE 1920x1080, EVEN THOUGH THE DELL/PRIMARY
DISPLAY IS 1920X1200???? I'm assuming so..) to a 1920x1200 DVI signal with letterboxing for input into the Dreamcolor.

The problem is, how to get a CROPPED (from the HDLink's 1920x1200
output) 1920x1080 signal into the Bravia. It cannot be a SCALED signal
form the 1920x1200 as this will yield an incorrect aspect ratio.

The other option would be to split the HD-SDI at the output of the
Quadro, put one side through the HDLink and then into the Dreamcolor
at 1920x1200 and put the other side through some kind of HD-SDI to DVI/
HDMI converter with a 1920x1080 output and into the Bravia that way..

I'm happy to spend a little bit of a solution for this .. not heaps,
but I understand I'll probably need two seperate converters at least.

The other thing that I'm confused about is that on the HDLink specs,
it stats that it can do either 1920x1080 output to HDMI, OR 1920x1200
output to DVI... because of HDTV and PC Standards.. this is close to
what we need, but simultaneously ..

Also, the Bravia should accept a 24p signal and the Dreamcolor will
accept 24hz (or 48)..

If anybody has some advice on how we can hook all this up to give us
the best quality display .. keeping in mind that the Dreamcolor is our
Grading monitor, so the signal going into it has to be primo, and the
Bravia needs to be a fullscreen, but cropped version (16:9 vs 16:10)
of the SAME signal.. that would be really great. I really need to
order whatever equipment we decide on in the next 48hours..

I'd love to hear how other people have their display paths set up..
realizing that most people will be using SDI directly into their
grading monitors... but are you also going SDI directly into the client
monitors as well? Or doing something similar? Anyone using HDTV's for
the client monitor?

Before anyone ask's.. we chose the Bravia because we wanted a consumer
display (ableit a good one) so that we can show clients what it will
look like when viewed on consumer displays.. and so we can prepare for
that in the grade, we have the reference monitor to watch as well..

The Dreamcolor input doesn't HAVE to be 10-bit.. but ideally it wold be. Most important thing is that the screens all work at the proper resolutions/aspect rations for now, we can always upgrade to 10-bit on the Dreamcolor when suitable hardware is available (if none is now).

Thanks guys!
Seth.

[Seth Larney]

Ok, so this seems to be the opposite of what we want to do :

The HDLink outputs 1920x1200 from the SDI ... in 8-bit (need 10-bit for the Dreamcolor at that res)

Then the MOTU V4HD outputs 1920x1080 from the SDI ... in 10-bit (need 8-bit for the Bravia at that res).

Arrrrggg.. any other ideas?

[Blair S. Paulsen]

Seth- I am dealing with a very similar set of issues. My post vendor, KeyCode Media in Studio City, might be worth contacting if you are still looking for solutions.

Cheers-

[Vico Martin]

downconvert with aja SDIHD to composite, same question in a flat philips!

[Evangelos Achillopoulos]

Seth, there is no way to color manage two displays for film out in tandem or in parallel, they will not be equal looking even if the have separate LUTs, the two monitors are not decoupling's equally unless the are exactly the same displays...

So the client (imaging an demanding DoP) will not see the grade as the colonist will, and thats bad practice. Also a smaller screen tend to show as an optical illusion more contrast than a bigger screen so the colorist will try to soften the image and the DoP will need to push contrast more...

[mikeburton]

Seth, if I'm not mistaken, isn't HDMI 1.3 a 10bit signal? If so couldn't you go HDMI out the computer to the Dreamcolor monitor for color critical and DVI to HDMI (8bit signal) to the client monitor? Or SDI to the Dreamcolor and HDMI to the client. If I understood your first post in this thread it sounds like you are worried about the scaling issue between 1920x1080 and 1920x1200 on the different monitors? I would suggest giving the guys over at Silverado Systems a call. They can sell you what you need as well as get you up and running.

[Seth Larney]

Seth, there is no way to color manage two displays for film out in tandem or in parallel, they will not be equal looking even if the have separate LUTs, the two monitors are not decoupling's equally unless the are exactly the same displays...

So the client (imaging an demanding DoP) will not see the grade as the colonist will, and thats bad practice. Also a smaller screen tend to show as an optical illusion more contrast than a bigger screen so the colorist will try to soften the image and the DoP will need to push contrast more...

Hi Evangelos,

Thanks for the input. We are not too worried about matching the client display to the reference monitor as the client can watch the reference monitor for color checks and then sit back and watch the 40" for an idea on what it will look like on a consumer display, that's the plan for now. This is because we have no room for a projector, we'll get the bravia 'as close as we can' but it won't be used for color reliance. This is just a workflow that we're going to have to make work.

[Seth Larney]

Seth, if I'm not mistaken, isn't HDMI 1.3 a 10bit signal? If so couldn't you go HDMI out the computer to the Dreamcolor monitor for color critical and DVI to HDMI (8bit signal) to the client monitor? Or SDI to the Dreamcolor and HDMI to the client. If I understood your first post in this thread it sounds like you are worried about the scaling issue between 1920x1080 and 1920x1200 on the different monitors? I would suggest giving the guys over at Silverado Systems a call. They can sell you what you need as well as get you up and running.

Hi Mike,

We have since gotten rid of the resolution difference issue as the Dreamcolor can operate in 1920x1080 mode and add black bars (which we originally thought it couldn't do) as opposed to cropping. So we can feed a 1080p signal to both screens ok... which is great.

Also, the options you mention would be ideal.. but they just don't work with Scratch pus Nvidia drivers. (there's no 10-bit output from the Nvidia without HD-SDI and there's no way to do fullscreen monitoring in Scratch without image tearing on audio sync unless you use HD-SDI - this is a limitation on HDMI/DVI and not Scratch).

The next problem is producing a HDMI 1.3 10-bit signal from the 10-bit HD-SDI output on the Nvidia. The DAVIO from Cine-tal looks like the first box that will do this, however it doesn't seem to be available yet.

The last issue, is - will the Bravia accept the 10-bit HDMI 1.3 signal, and just display 8-bits (as it's an 8-bit panel).... or will it choke on the 10-bit signal... this is a deal breaker as I can't see how to convert the 10-bit HDMI to 8-bit AFTER the HD-SDI to HDMI conversion (as we need 10-bit for the Dreamcolor).. unless I split the HD-SDI beforehand and then use 2 serperate converters to HDMI that will produce 10-bit and 8-bit respectively, which should be possible providing the DAVIO gives us 10-bit.

Arg.. so close..

Cheers,
Seth.