Multi Screen Video

[gearhead401]

Its a few months away but I am working on a show with a school attempting to incorporate video into some of their shows. We attempted last year with Qlab 2 but began having issues when we tried to incorporate more then one video. They want to add in live feeds and multi screen use and feeds this year. The goal is to use 4 projectors mapped out in qlab. The issue becomes the latency issue and lagging from the computer. We have a Mac mini with 8gb, a macbook pro with 4gb, and a mac pro with 4gb. I am wondering what the best plan of action as far as being able to get the 4 feeds from the computer. Someone had suggested using an out board video processing unit, unfortunately I don't know what any of that means. Any help is greatly appreciated. I do have a video card for the mac pro that would give me 2 more outputs totaling 4 on that computer, but it lags big time for what I assume is processing. Thank you!

 

[chausman]

Where is the media coming from? External drive, Internal HDD, SSD? That might cause significant lag time as well.

 

[gearhead401]

Where is the media coming from? External drive, Internal HDD, SSD? That might cause significant lag time as well.

It was all stored on the internal HDD, would it be better stored elsewhere?

 

[dgoodmanedberg]

I've heard good things about Isadora, especially with live feed handling, though you might also want to try upgrading to the new Qlab 3 which vastly improves its video/projection capabilities. If you need to have more than one screen, you'll have to start looking at external video cards to run them.

Alternatively, if you have massive amounts of money lying around, you could start looking into media servers and their associated programs.

 

[jclampe]

Maybe you can give ArraySync a try if you only want to play out video in sync. - well, personally i never tried it, but for ~ 30 bucks, it should be worth a try.
https://itunes.apple.com/de/app/arraysync/id415935093?l=en&mt=12

If you want to add a camera live feed you will always have problems with latency - especially in the low cost sector.
One of the best solutions (and actually one of the most expensive ones) would be a media server (e.g. Pandoras Box or Dataons Watchout, which is def. easier to handle) for video play out in conjunction with Barco's Encore system for adding the live feed to the multiscreen setup. The live camera latency of the Barco system is currently unbeatable.

 

[Drew Schmidt]

QLab 3 is a vast improvement over QLab 2. But you have to have 10.8 or higher to run it. QLab 3 can easily handle multiple screens, but looks like your computers really aren't setup to handle 4 at a time. With that said, you can use all three simultaneously. QLab 3 has a new OSC cue, think MIDI and MSC over ethernet. If you have all three computers connected to your network, using one computer to control the other two is a breeze. Here you'll just need to figure out how to get 5 discreet outputs (5th being your control screen, obviously that should be your MBP LCD screen). And of course with QLab's academic rental license, you could rent the full version for the duration of your show for $3/day and put it on as many machines as you have.

Holler if you need help setting this type of system up, but unless you go to a large media server or are willing to drop more cash into one of your existing systems, this is probably the best solution for 4 screens.

I'll add this, you can also get multiple discrete screens using the Matrox TripleHead2Go ... but now you're outputting a very large video and can potentially bog down your system.