Re: syncing 2 16mm projectors

From: Joost Rekveld (email suppressed)
Date: Sun Sep 30 2007 - 17:40:15 PDT


a few remarks from somebody who is not an expert on these things:

- i've seen some kind of adapter which allowed you to connect three
projectors to a laptop. I understood that it behaves like one monitor
of, say 3072 by 768 pixels, and cuts this in three. Don't know how
this is called, though.
- you can add graphics cards and there are also graphics cards with
two outputs, so you can run 4 or even 6 monitors from one desktop
- max/Jitter is not particularly good at playing back video at pal-
like resolutions or higher: it tends to stutter, and that is because
Jitter is not optimized to do this; it is optimized for real-time
manipulation or generation of images.
- when you play back multiple streams at once, you are likely to run
into harddisk speed problems, unless you use RAID-stuff.
- i've seen a few systems to play back clips on multiple projectors
and most of them use one computer per projector, synchronized over a
network. There is software to do this, but I don't know any names..

hope this helps a bit,


On Sep 29, 2007, at 2:18 , Klaus W. Eisenlohr wrote:

> Dear Mike,
> Masking is not really an option, I feel, I do not want to build a
> case around monitors (it is easier with projections, I agree.
> However I wanted to share what I found out so far:
> 1) The mentioned video card VTBook for powerbooks does not allow to
> play 3 independend monitors, it does only give one additional
> monitor to the powerbook, and the opportunity to mirror another one
> with an adapter (the advertising on
> vtbook/index.html, thus is kind of a hoax)
> 2) On the other hand, it seems it is easy to add a AT Radeon PCI-
> Card to the G4 Desktop (I am owning a G4 mirrored doors) and thus
> add additional two monitors, if the requirements on resolution are
> not too high. Prices seem to be reasonable too: under 200 ¤.
> 3) With the VLC player it is possible to have two or more copies of
> the application running and YES have them in presentation mode on
> different monitors. The downside is that the VLC player is very
> slow and buggy, it crashes frequently, it has problems playing back
> sound if the bitrate of the stream is too high (does not play DV
> comporession), AND I found out that it does not stay in sync when
> looping two movies on two monitors, I had a difference of a second
> after playing a short clip for around 30 minutes.
> 4) (I could not get mplayer to run on my OS)
> My conclusion so far: I guess I will try out the extra Video card
> in my desktop G4 for futur shows, but I guess for now, I will try
> to get 3 identical consumer DVD players, which I can operate from
> one remote control, and then live with the glitch for the upcoming
> show with 3 screens.
> Thank you to everybody
> Klaus
>> You should be able to put the two video streams together side by
>> side into one quicktime movie and then just let quicktime play it
>> back. You may not be able to go fullscreen without it
>> constricting itself to one screen, but if you pull the window out
>> to cover both screens, you should be able to cover most of both of
>> the screens with video. What is not video should be pretty easy
>> to mask out with something like black wrap or even some cardboard
>> (though be careful if it's a really hot projector). I'm also
>> guessing that some software made specifically for live video
>> mixing might be able to do the two-screens-two-videos thing, but
>> short of that or Max/MSP or something that is on the verge of
>> getting really technical, nothing comes to mind.
>> Hope this helps!
>> Mike
> --
> Klaus W. Eisenlohr, Osnabrücker Str. 25, D-10589 Berlin, Germany
> email: email suppressed
> and film production:
> phone: int.- 49 - 30 - 3409 5343 (BERLIN)
> __________________________________________________________________
> For info on FrameWorks, contact Pip Chodorov at <email suppressed>.

For info on FrameWorks, contact Pip Chodorov at <email suppressed>.