Signal Format Conversion

[peternewman]

Hi all,

 

For a show we've got coming up soon, we need to create an art installation which consists of lots of random TVs in various states of disrepair. We need to put various content onto them, including a video wall style effect at one point, so I recently managed to acquire a video wall processor made by new Digimatic.

 

The unit itself appears to be a DIGIMAX3 (working image on the tech spec page) or DIGIMAX32, but in an ECO DTV size box, although still using the card system of the larger model. Anyway this is all somewhat irrelevant I'd guess. Basically the issue is the system outputs RGB, whereas I'd mistaken the large collection of BNC connectors on the spare unit as outputs. So I ideally need a way to make use of these RGB outputs. I've got the pinout to connect to Selco (I believe, someone other than Barco, who the guy said use a different pinout). Anyway the output specs are:

RGB analog 0.7 Vpp - 75 ohm load (RS 343A Compatible)

Composite Negative Sync 31,2- 31,4KHz 50/100 - 60/120Hz

Firstly I assume the composite sync is combined H & V not a composite video signal, which would be wishful thinking. Basically ideally I'd like to use this, as it means I won't need to bodge something together with multiple scan converters. However they will probably be standard TVs or could possibly be computer monitors. So firstly is this output compatible with TVs/PC monitors, I see RGB mentioned in the Scart pinout, is this the same format or a different one?

 

Alternatively if the format isn't compatible with TVs/Computer monitors, and indeed what may be preferable, is to convert it to Composite/S-Video. I assume this won't be quite the walk in the park that composite to S-Video conversion is, and so far I've found this which appears it would do the job, although given I'll probably be looking at a 2x2 wall at the minimum I could do with something cheaper.

 

So what do people suggest, my previous experience has only really been with composite/S-video rather than all these component/RGB formats.

 

Thanks,

 

PN

[henny]

after having a quick google round it semes that if you want to feed RGBs in to a RGB scart socket you simply conect the rgb to rgb and the comp sync to the Composite pin.

 

5 RGB Blue Ground

7 RGB Blue Signal (0.7Vpp 75 ohm)

9 RGB Green Ground

11 RGB Green Signal (0.7Vpp 75 ohm)

13 RGB Red Ground

15 RGB Red Signal (1Vpp 75 ohm)

17 Composite Video Ground

20 Composite Video In (1Vpp 75 ohm)

 

of if you want to cheat but seing that your controler out on a s-video conector I would just buy some 10m s-vid leads lb them in 2 and conect up to a scart conector as mentoned above

 

ian

[Tomo]

With straight RGB (or YUV/YPrPb) video, the sync is on one of the colour lines (the green connector IIRC)

 

Most PC monitors will not receive it.

 

Many TVs that have a SCART socket will, but do check if your chosen ones can - the spec should say something like "RGB/YUV/YPbPr input via SCART socket"

If you are competent with a soldering iron you could build suitable adaptors for the price of some 75ohm BNC coax and SCART plugs.

 

Don't tie the grounds together - ensure that the shield from Red goes to Red Ground, etc

 

Edit:

Now I've read through some of that lot - it's not the three-wire connection I thought.

Which means all the above isn't going to help you. :)

 

Sorry.

 

Edit:

And the box that Henny suggests is absolutely perfect - RGB plus Sync.

 

God knows where the Sync pin is - none of the SCART pinouts I have label one of those!

[soundo26]

what you need is a basic videowall controller such as an imagemag, which you might be lucky enough to pick up cheaply on e-bay. Alternatively you can hire one from a videowall specialist company such as Piccadilly ARB who are based in Buckingham (you never know, they might even have an old one they wish to move on)!

[henny]

God knows where the Sync pin is - none of the SCART pinouts I have label one of those!

you use the composite in as sync in

 

Don't tie the grounds together - ensure that the shield from Red goes to Red Ground, etc

 

in thise you carnt because digi max outputs a common ground

[peternewman]

Thanks for your help so far everyone, a few more questions if you don't mind.

after having a quick google round it semes that if you want to feed RGBs in to a RGB scart socket you simply conect the rgb to rgb and the comp sync to the Composite pin.

Many TVs that have a SCART socket will, but do check if your chosen ones can - the spec should say something like "RGB/YUV/YPbPr input via SCART socket"

Now it gets interesting (and I realise this may be a bit of a how long is a piece of string type of question) we're going to be getting all sorts of TVs from various sources like tips, auctions, freecycle etc. How common is an RGB input likely to be, did it become commonplace after a certain time, or is it a cost based and only the higher end brands are likely to have it?

 

With straight RGB (or YUV/YPrPb) video, the sync is on one of the colour lines (the green connector IIRC)

 

Most PC monitors will not receive it.

I realise at the time you were talking about RGB with sync on green, will PC monitors manage to receive it when its RGB and a composite sync or is it voltage/frequency/etc related issues.

 

what you need is a basic videowall controller such as an imagemag

I've already got a video wall processor Soundo, that's what the question is about, I couldn't find much on imagemag, or are you referring to an additional controller to go with the processor, I don't think the one for my wall would make it output composite.

 

Also it would still be great if I could convert it to Composite/S-Video on the cheap, as then I can deform the wall through a matrix or two, so if anyone know how to do that cheaply that would be great thanks.

[Tomo]

Don't tie the grounds together - ensure that the shield from Red goes to Red Ground, etc

in thise you carnt because digi max outputs a common ground

Comment still applies!

For good shielding, the shield should be connected at one place only - if you connect them together at boths ends of the wire, it's possible to create ground loops and other nastiness.

 

Data sources often connect grounds together, but data sinks should not.

[Jivemaster]

CCTV Monitor Adaptor

WAS £59.99 SAVE £20.00 Until 15/05/2007 N78CQ 668 39.99

 

Any interest?

[peternewman]

Wrong way for this application, but may be of interest in future.

[peternewman]

Okay a bit of an update, we need to be able to swap bits of the video wall around, so I really need to convert them all to composite now, to send through a video matrix (yes I realise I could move the screens virtually using the video wall software, but for various reasons and future use, I'd prefer to convert to composite). I'm looking at a 2x2 wall, so four converters in total, however they seem to be relatively expensive, so four cost quite a bit. So I was wondering if anyone knows of any cheap sources for them, the best I've found so far are around £40/50 each. Expensive also being a somewhat relative term, I got the video wall controller for £0.99 from eBay :), so would rather not spend loads on the other bits.