HELP PLEASE needed with video wall!

[alexwhite]

Hi,
I've gone out on a limb in the hope of setting up a 4x4 16 screen video wall to present television / video art on.

I boiught 5 Imtech Ultra Decoder racks on Ebay from the US like these:



They have a range of inputs (composite, svideo, RGBS, component) and each then (in theory) outputs four qaudrants of the input image (I hope). The outputs are a bit trickier - they are 9 pin serial outputs label with RGBSHV



After a bit of research I think the outputs are the multisync standard used for monitors:

http://www.pcmag.com/encyclopedia/term/ ... nc-monitor

My plan was to feed one rack with the signal and then divide that signal out to each of the four remaining to achieve a 16 screen wall.


I've source 13 20" Sony BVM-2016P that all function adequately and I'm hoping to find another 3. These have SDI, composite and RGB inputs. I'm wondering if there is a simple way to connect these to the Imtech racks?

My initial thought was to connect the imtech outputs to VGA connectors - i still haven't been able to test this theory yet but from everything I've read these outputs should be compatible with VGA. I was then going to use some extremely cheap VGA to composite converters to get into the TVs.

But I'm wondering a couple things:

Has anyone worked with imtech gear in the past? Or with a 9 pin serialesque standard?

And is there any way of easily converting RGBSHV to RGB with a custom cable? Or is sync on green already there? and all I need to do is connect the RGB?

Any help much appreciated - you can borrow it if we get it functioning! (and you live in Sydney)

cheers Alex

[daverj]

Do you have a scope?

CGA, EGA, and NEC VGA all used DB-9 connectors, but had different pinouts. And all were RGBHV. I don't know if this uses the same pinouts as one of those or their own format. Plus I don't know where the "S" is coming from. Maybe there is a switch inside to change between RGBS and RGBHV?

[waveglider]

Here's the DB9 pinouts from info I found:

1-Ground
3-Red
4-Green
5-Blue
6-Select
7-Composite Sync

The Select line is a DC voltage output used to tell older SCART gear what type of aspect ratio is present.
I'm not sure why the silkscreen on the outputs says RGBSHV when there is no H/V sync on the inputs

[daverj]

These are from this specific product? They are different from the multi-sync or earlier (CGA/EGA) connectors.

Plus there's still 2 more pins. Maybe the H & V are on those?

[wcfields]

Are you sure you don't also need a controller? I think the decoders are to take an existing signal and convert it to RGBSHV for use in the controller system.

http://www.ebay.com/itm/IMTECH-HIGH-DEF ... 338365a546

[bitSmasher]

This would be pretty epic, relatively cheap too... If I had a spare grand I'd buy it!
http://www.ebay.com.au/itm/Video-Wall-1 ... cbc&_uhb=1

[giorgio]

i'm working on a wall as well but building the whole thing out of raspberry pi computers, 1 for each TV all slaved to a master computer.

[johnnywoods]

i'm working on a wall as well but building the whole thing out of raspberry pi computers, 1 for each TV all slaved to a master computer.

this seems to be a popular new solution! wcfields had a great piece up here in LA recently that made use of the same technique. this got me thinking about possibly using multiple pi's into a video mixer/lzx setup. Could be a cool way to do live edits of synchronized material (like for a music video). How big of a PITA is the setup?

[wcfields]

i'm working on a wall as well but building the whole thing out of raspberry pi computers, 1 for each TV all slaved to a master computer.

Yeah I followed the piwall.co.uk instructions.

Things that rule:
* Cheap

Things that suck:
* It's super finicky to "start-up"
* A master PI doesn't do a good job of transcoding (I've only been getting ~10fps)

[giorgio]

* A master PI doesn't do a good job of transcoding (I've only been getting ~10fps)

why not use a laptop as the master?

[wcfields]

* A master PI doesn't do a good job of transcoding (I've only been getting ~10fps)

why not use a laptop as the master?

That's what I've been doing, using VLC to do a multicast stream. Trouble is that the installation is usually further away than I'm using my laptop. I've been experimenting with direct connection with a Wifi adapter, but haven't had enough time to configure it 100%.

I also installed parallel linux tools (http://code.google.com/p/parallel-ssh/) which allow you to run SSH commands simultaneously, so I can do a kill-all of the pwomxplayer and starting it back up too on all the Pi's at once.