Mac Mini & HDMI to Projector Issues

[Frank Nickel]

Trying to get Qlab to output video to a projector through the HDMI
port. I'm trying to avoid buying a second mac mini to just power the
projectors. Here is my setup attempt:

Mac mini powers the computer display through the mini display port.
This is so the stage manager can view the Qlab main window and run the
show.

Using the HDMI port, I purchased a StarTech HDMI2VGA video converter.
I plugged one projector into the converter. Technically, the StarTech
is a splitter so you could technically power two projectors.

In system preferences / Monitors it does detect the HDMI gadget and I
turned off mirroring, but I can't figure out how to get Qlab to output
to the second screen.

I've read how the Matrox video splitter has not worked perfectly with
Qlab in the past and I'm wondering if getting the HDMI output and
converting to VGA is just a bad idea.

In the end, do I really need one computer per projector output with
one computer to trigger the other computers?

Is there a Qlab guru in Vancouver BC I could pay to chat with in
person at my theatre?

Thanks all,
Frank Nickel | Pacific Theatre

[luckydave Memory]

Hi Frank.

Looking at the HDMI2VGA on Startech's website, I don't see it listed as
a splitter at all. I don't think that functionality affects what you're
trying to do anyway, though. Once you've turned off mirroring, and
arranged your displays in a way that makes sense to you in the Displays
pane of System Preferences, launch QLab (if it's open, quit and relaunch
it so it has those settings in place when it launches). Go to Workspace
Preferences, to the Video section, and connect the screen patch you're
using in your video cues to the projector (or Startech device, however
it's representing itself). Then your cues will be on that display. If
you set the cues to full screen, they'll be scaled to fit the output
resolution, and if you're using Custom Geometry, you'll have to place
them manually in the projector's raster. You may want to change the
Global Origin in the Video settings if you're using custom geometry.

I'll also point out that the Matrox devices work fine with QLab, there's
just a little more work necessary to program the show for them, since
they appear as a single display that's double (or triple) the width of a
single display, so full screen mode doesn't work. Functionally, they
work well, but it's just a little more trouble to do so. Totally worth
it for the ability to connect to multiple projectors from one display
output, though.

The next thing to keep an eye on is the Mini itself. No Mini is a strong
video machine, and if it's not from the latest refresh of the line, it
won't have a discrete graphics card, but will be using a GPU that's
integrated with the CPU, which isn't good for playback performance. If
the card's integrated, you'll also be using your main system RAM as
vRAM, which doesn't get prioritized to video, so can be otherwise
purposed whenever the OS decides it's a good idea. So, if you start
running into performance issues, that may be a good place to look.

Thanks,
luckydave

[Frank Nickel]

Thanks muchly. Got the second screen working from the HDMI2VGA thanks
to your post.

I looked at the mac mini specs and its got a NVIDIA GeForce 320M
graphics card, with a Intel Core 2duo at 2.4 and 2GB of system RAM.
Some of the fades are choppy so I can see the card chugging through
some of the work. Its not the best, I agree.

Thanks for the reply.
Frank

[luckydave Memory]

Frank Nickel

February 8, 2012 2:55 PM

I looked at the mac mini specs and its got a NVIDIA GeForce 320M
graphics card, with a Intel Core 2duo at 2.4 and 2GB of system RAM.
Some of the fades are choppy so I can see the card chugging through
some of the work. Its not the best, I agree.

It's not the strongest video machine, that's for sure. The choppy fades issue does make me think it's the graphics card working as hard as it can, and needing to work just a little harder. You can confirm that with the free atMonitor utility, which will show you the work load on each component of your system, including the GPU and vRAM.

Thanks,
luckydave

[Chris Eschweiler]

Hi Frank.

Does your video reside on the Mini's internal drive? If so, what you may be experiencing is a data bottleneck.

When use the Mac Mini for Playback Pro, I keep the media on an external Firewire 800 drive. This keeps the OS and application use separate from data being accessed.

Fades with QLab require a lot of processing, and if QLab's trying to keep up with accessing a file AND processing a fade, many computers will chug at that level.

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