Synchronizing 3 projections

Mar 31, 2007 at 6:08pm

Synchronizing 3 projections

Hi-

I need to synchronize 3 projections and I am not sure where to begin as I have only played with Jitter for about a week total. Each projection will play different video clips that need to be synchronized with one another, and this will be projected on 3 separate walls.

Besides that, I’m not sure how I get three separate projectors to connect to a computer running Jitter.

I know this is probably a simple request, I’m just so new to Jitter.

Any help is appreciated.

Many thanks in advance

#31106
Mar 31, 2007 at 10:01pm

How do I output a high res matrix? Am I using Jitter to do this? I’d prefer to run off one machine as I don’t know if I’d have the resources to come up with two other machines.

Many thanks

#100603
Mar 31, 2007 at 10:20pm

OpenGL with Jitter and matrox triple head to go..

On Mar 31, 2007, at 6:01 PM, Christopher Lowther wrote:

>
> How do I output a high res matrix? Am I using Jitter to do this?
> I’d prefer to run off one machine as I don’t know if I’d have the
> resources to come up with two other machines.
>
> Many thanks

v a d e //

http://www.vade.info
abstrakt.vade.info

#100604
Mar 31, 2007 at 11:27pm

And this will allow me to synchronize 3 separate video (Quicktime) files? It’s not one file that I want spread over 3 screens, but rather 3 different files playing at the same time and projected.

Thank you for you help

#100605
Mar 31, 2007 at 11:57pm

well, if they are the same length simply send the time $1 message to
all three ?

On Mar 31, 2007, at 7:27 PM, Christopher Lowther wrote:

>
> And this will allow me to synchronize 3 separate video (Quicktime)
> files? It’s not one file that I want spread over 3 screens, but
> rather 3 different files playing at the same time and projected.
>
> Thank you for you help

v a d e //

http://www.vade.info
abstrakt.vade.info

#100606
Apr 1, 2007 at 4:01am

Ok, I’ll try this. I ordered the Matrox TripleHead2G today and should be here Wed.

Thank you very much for your help

#100607
Apr 1, 2007 at 4:53am

I forgot to ask another question. Will I also be able to have 3 separate audio coming out for my 3 different video projections? I won’t be hooking up to monitors, but rather projectors and I assume I can just hook whatever sound system I want to that.

Thanks again

#100608
Apr 1, 2007 at 5:27am

Assuming your computer has a way to output multichannel audio, yes. So if you want to send 3 stereo pairs, you will need 6 discrete analog outputs; if 3 mono signals, then just 3 analog outs. Once you have your soundcard or audio interface hooked up and drivers installed, then you choose the appropriate driver in Max’s DSP window. There you can also map Max’s logical input and output numbers to the physical ins and outs on your audio hardware. If you are using the first three analog outputs on your audio interface, then the default mapping is likely fine, with Max’s audio outs 1-3 mapped to the physical analog outs 1-3.

In your patch, use the dac~ object with the arguments 1 2 3 (or 1 2 3 4 5 6 if you need six channels of audio). This will give you a dac~ with three inlets that correspond to the first three outputs of your hardware. Then, just hook them up to your projectors and patch away!

Cheers,
Tim

#100609
Apr 1, 2007 at 7:31pm

You miss one point now: when playing movies in jitter the audio is handled by the quicktime library by default.

When you want to play with the audio and/or output them on seperate physical channels as tim says you need to a) use spigot~ or b) load the audio in a buffer~ seperately and sync the movie to the audio. I strongly prefer the last option. Search this forum for examples how to do this.

If you don’t want to play with the audio, just let quicktime handle the audio, it will send everything together out your default sound output.

Cheers,
Mattijs

Quote: tim_thompson@mac.com wrote on Sun, 01 April 2007 07:27
—————————————————-
> Assuming your computer has a way to output multichannel audio, yes. So if you want to send 3 stereo pairs, you will need 6 discrete analog outputs; if 3 mono signals, then just 3 analog outs. Once you have your soundcard or audio interface hooked up and drivers installed, then you choose the appropriate driver in Max’s DSP window. There you can also map Max’s logical input and output numbers to the physical ins and outs on your audio hardware. If you are using the first three analog outputs on your audio interface, then the default mapping is likely fine, with Max’s audio outs 1-3 mapped to the physical analog outs 1-3.
>
> In your patch, use the dac~ object with the arguments 1 2 3 (or 1 2 3 4 5 6 if you need six channels of audio). This will give you a dac~ with three inlets that correspond to the first three outputs of your hardware. Then, just hook them up to your projectors and patch away!
>
> Cheers,
> Tim
—————————————————-

#100610
Apr 1, 2007 at 11:24pm

Absolutely right–sorry I passed over that crucial point. I rarely use the audio that is recorded in a movie file, but when I do, I prefer to extract it from the video file and play it back from buffer~.

Quote: Mattijs wrote on Sun, 01 April 2007 15:31
—————————————————-
> You miss one point now: when playing movies in jitter the audio is handled by the quicktime library by default.
>
> When you want to play with the audio and/or output them on seperate physical channels as tim says you need to a) use spigot~ or b) load the audio in a buffer~ seperately and sync the movie to the audio. I strongly prefer the last option. Search this forum for examples how to do this.
>
> If you don’t want to play with the audio, just let quicktime handle the audio, it will send everything together out your default sound output.
>
> Cheers,
> Mattijs
>
> Quote: tim_thompson@mac.com wrote on Sun, 01 April 2007 07:27
> —————————————————-
> > Assuming your computer has a way to output multichannel audio, yes. So if you want to send 3 stereo pairs, you will need 6 discrete analog outputs; if 3 mono signals, then just 3 analog outs. Once you have your soundcard or audio interface hooked up and drivers installed, then you choose the appropriate driver in Max’s DSP window. There you can also map Max’s logical input and output numbers to the physical ins and outs on your audio hardware. If you are using the first three analog outputs on your audio interface, then the default mapping is likely fine, with Max’s audio outs 1-3 mapped to the physical analog outs 1-3.
> >
> > In your patch, use the dac~ object with the arguments 1 2 3 (or 1 2 3 4 5 6 if you need six channels of audio). This will give you a dac~ with three inlets that correspond to the first three outputs of your hardware. Then, just hook them up to your projectors and patch away!
> >
> > Cheers,
> > Tim
> —————————————————-
>
>
—————————————————-

#100611
Apr 1, 2007 at 11:31pm

Ok, many thanks for all this help. I’ll have 3 projections, and two of the projections will have someone talking, so when the projections are faced across from one another they appear to speak to one another. I hope this synchronization that you are talking about is exact since it is dialogue and not ambient sound.

And, so I thought it would be nice to have each person’s audio/voice coming from that part of the room to make it more dynamic, instead of hearing it everywhere at one.

I get my Matrox in a couple of days and I will let you know how it goes.

Thanks again for such great help

#100612
Apr 2, 2007 at 12:44am

The objects that you can use to play the contents of a buffer~ object are quite flexible and allow for a great deal of precision. Check out the help files for buffer~, groove~, and play~.

tim

#100613
Apr 3, 2007 at 9:36am

>>>I hope this synchronization that you are talking about is exact since it is dialogue and not ambient sound.

Been looking into a three-synced-projectors thing myself. Thinking that one way to go is to comp three 640 x480 movies together as a single 1920 x 480 Quicktime. Then play this single movie in a window exactly the same size as the Matrox desktop running, as it can, at 1920 x 480.

That means there’s no way to lose sync.

You’d probably need to run this off a desktop machine with at least 2 or 3 drives striped together. Data rate worked out at about 24 mb/s.

Being an installtion, if you don’t get exact sync by just playing the movie, for whatever reason, you could always introduce a video delay subpatch and an audio delay subpatch, then tweak the delay time until they come into sync again.

Please let me know how you get on with the Matrox Tripletogo box as I’m thinking of using one myself.

#100614
Apr 3, 2007 at 10:38am

We play 4 video sources, perfectly synced, together in 3072 x 768 on the matrox triplehead2go, from one hd.

Mattijs

Quote: lyallmarcus wrote on Tue, 03 April 2007 11:36
—————————————————-
> >>>I hope this synchronization that you are talking about is exact since it is dialogue and not ambient sound.
>
> Been looking into a three-synced-projectors thing myself. Thinking that one way to go is to comp three 640 x480 movies together as a single 1920 x 480 Quicktime. Then play this single movie in a window exactly the same size as the Matrox desktop running, as it can, at 1920 x 480.
>
> That means there’s no way to lose sync.
>
> You’d probably need to run this off a desktop machine with at least 2 or 3 drives striped together. Data rate worked out at about 24 mb/s.
>
> Being an installtion, if you don’t get exact sync by just playing the movie, for whatever reason, you could always introduce a video delay subpatch and an audio delay subpatch, then tweak the delay time until they come into sync again.
>
> Please let me know how you get on with the Matrox Tripletogo box as I’m thinking of using one myself.
—————————————————-

#100615
Apr 3, 2007 at 1:34pm

Hi-

Thanks for the feedback! It’s funny you mentioned that, because I was just asking a friend the other day, “I wonder if you can just create a movie and let the Matrox split it up into 3 movies?”

So, I wouldn’t be able to have movies at 720X480?

I was reading online reviews of people using the Matrox for Games and Simulations, and one guy said that his system never lagged, but he had a 2GB proc. So, you really think I need more than one hd?

It should be here anyday…I’ll let you know when it arrives, if I have problems, and how it performs.

Many thanks for all your help!

#100616
Apr 3, 2007 at 1:47pm

Quote: Dart wrote on Tue, 03 April 2007 15:34
—————————————————-
> Hi-
>
>
> Thanks for the feedback! It’s funny you mentioned that, because I was just asking a friend the other day, “I wonder if you can just create a movie and let the Matrox split it up into 3 movies?”
>
> So, I wouldn’t be able to have movies at 720X480?

Why not? jit.qt.movie will play anything. You can then put it on a texture and render it in a 3D space of any dimension you want on any position you want.

>
> I was reading online reviews of people using the Matrox for Games and Simulations, and one guy said that his system never lagged, but he had a 2GB proc. So, you really think I need more than one hd?

There is always the option of loading the movies in ram (check jit.qt.movie helpfile). The maximum is 2GB even if you have more but that should be enough for a lot of stuff (depending on the codecs).

Mattijs

#100617
Apr 3, 2007 at 1:49pm

>
> Thanks for the feedback! It’s funny you mentioned that, because I was just
> asking a friend the other day, “I wonder if you can just create a movie and
> let the Matrox split it up into 3 movies?”
>
> So, I wouldn’t be able to have movies at 720X480?
>

You can create movie at 720×480, but then you’ll have to use 3 separate
videoplanes and position them as desired.

The thing is, the tripleHead2Go appears to your pc/mac as a virtual display
with a ratio of 12:3, so you can do anything u like with that space. when
you fullscreen a jit.window on that virtual display it’ll be 2160×480, but
you can still position 720×480 videoplanes on it.

The thing is, if u play movies of 2160×480, that movie must come from one HD
only, so this demands a pretty high datarate from your HD >> use multiple
striped HD’s as mentioned before, or split into 3 separate files located on
separate disks to overcome the datarate issue.

I’ve used this latter technique several times and it works pretty fine. The
TripleHead2Go really is a nice piece of equipment.

#100618
Apr 3, 2007 at 2:05pm

Quote: mojo wrote on Tue, 03 April 2007 15:49
—————————————————-
> The
> TripleHead2Go really is a nice piece of equipment.

Yeah, it’s perfect. One warning: when the triplehead2go is suddenly detected as a 4:3 monitor just before your performance starts, don’t panic, likely that the matrox’ power supply is disconnected. :p This happened to me last week..

Mattijs

#100619
Apr 3, 2007 at 2:06pm

Doesnt jit.qt.movie load into ram the uncompressed 32 bit frames ? I
dont think the codec will matter, but the frame size and number of
frames you want to load into ram. I could be wrong though….

On Apr 3, 2007, at 9:47 AM, Mattijs Kneppers wrote:

>
> Quote: Dart wrote on Tue, 03 April 2007 15:34
> —————————————————-
>> Hi-
>>
>>
>> Thanks for the feedback! It’s funny you mentioned that, because I
>> was just asking a friend the other day, “I wonder if you can just
>> create a movie and let the Matrox split it up into 3 movies?”
>>
>> So, I wouldn’t be able to have movies at 720X480?
>
> Why not? jit.qt.movie will play anything. You can then put it on a
> texture and render it in a 3D space of any dimension you want on
> any position you want.
>
>>
>> I was reading online reviews of people using the Matrox for Games
>> and Simulations, and one guy said that his system never lagged,
>> but he had a 2GB proc. So, you really think I need more than one hd?
>
> There is always the option of loading the movies in ram (check
> jit.qt.movie helpfile). The maximum is 2GB even if you have more
> but that should be enough for a lot of stuff (depending on the
> codecs).
>
> Mattijs
> –
> SmadSteck – http://www.smadsteck.nl
> Interactive audiovisual sampling soft- and hardware
>

v a d e //

http://www.vade.info
abstrakt.vade.info

#100620
Apr 3, 2007 at 2:12pm

Quote: vade wrote on Tue, 03 April 2007 16:06
—————————————————-
> Doesnt jit.qt.movie load into ram the uncompressed 32 bit frames ? I
> dont think the codec will matter, but the frame size and number of
> frames you want to load into ram. I could be wrong though….
>

I am quite sure it doesn’t uncompress the movies in ram. When I load a 300 mb compressed file in ram the amount of used ram increases to 300 mb as well.

Mattijs

#100621
Apr 3, 2007 at 2:16pm

Correct, the data is loaded compressed into ram. If you want to store
uncompressed frames in ram, use jit.matrixset.

jb

Am 03.04.2007 um 16:12 schrieb Mattijs Kneppers:

>
> Quote: vade wrote on Tue, 03 April 2007 16:06
> —————————————————-
>> Doesnt jit.qt.movie load into ram the uncompressed 32 bit frames ? I
>> dont think the codec will matter, but the frame size and number of
>> frames you want to load into ram. I could be wrong though….
>>
>
> I am quite sure it doesn’t uncompress the movies in ram. When I
> load a 300 mb compressed file in ram the amount of used ram
> increases to 300 mb as well.
>
> Mattijs
> –
> SmadSteck – http://www.smadsteck.nl
> Interactive audiovisual sampling soft- and hardware
>

#100622
Apr 3, 2007 at 4:01pm

Ah, cool. I did not know that – glad I incorrectly mentioned it!
Learn something new every day!

On Apr 3, 2007, at 10:16 AM, Jeremy Bernstein wrote:

> Correct, the data is loaded compressed into ram. If you want to
> store uncompressed frames in ram, use jit.matrixset.
>
> jb
>
> Am 03.04.2007 um 16:12 schrieb Mattijs Kneppers:
>
>>
>> Quote: vade wrote on Tue, 03 April 2007 16:06
>> —————————————————-
>>> Doesnt jit.qt.movie load into ram the uncompressed 32 bit frames ? I
>>> dont think the codec will matter, but the frame size and number of
>>> frames you want to load into ram. I could be wrong though….
>>>
>>
>> I am quite sure it doesn’t uncompress the movies in ram. When I
>> load a 300 mb compressed file in ram the amount of used ram
>> increases to 300 mb as well.
>>
>> Mattijs
>> –
>> SmadSteck – http://www.smadsteck.nl
>> Interactive audiovisual sampling soft- and hardware
>>
>

v a d e //

http://www.vade.info
abstrakt.vade.info

#100623
Apr 3, 2007 at 4:21pm

So, if I wanted to run 3 Quicktime movies that are about 10 minutes apiece…no fancy graphics…what configuration of computer would you recommend to run this? I need to install something soon and I just want to know if I need to order a computer now or try and run it from my Dell PC (Dell 8400 Pentium 4 CPU, 3.20 GHz, 3.19 GHz , 1.0 GB RAM, NVIDIA GeForce 6800). I fear my machine is not fast enough for this project.

#100624
Apr 4, 2007 at 9:36am

The bottleneck in your system will not be any of the parameters you listed.
The issue will become HD datarate or RAM memory. The action that costs CPU
resource is the decompression of the clips, but with a 3GHz processor i
believe this machine should be capable of decompressing 3 clips at once,
given that you select a low cost video encoder (like photojpeg @ 75%). If
you render this to a texture or videoplane the rest of the work will be done
by your GPU which will no doubt have any trouble whatsoever with displaying
3 videoplanes at once. So it comes down to being able to playback 3 video
files at once which demands a certain datarate from your HD, you can
calculate this but testing a setup is still the best method in my opinion.
Solutions i suggest are:
- Loading one or two movies into ram which means that only one (or two)
movie(s) will have to be read from disk. This might mean expanding your RAM
- buy extra HD’s and stripe them (raid 0 or raid 5 are both interesting),
but this will have to be supported by your motherboard. This enables you to
get the datarate you need. you then might even be able to encode your clips
using a DV encoder (= raw yuv data), which takes away the work for the CPU.
- budget solution: one clip into ram, one from your HD and one from an
external HD.

i did some projects with the ‘budget solution’ but i wouldn’t recommend it.
If you want reliable performance i’d go for multiple HD’s with RAID enabled
(preferrably raid5 or raid10).
more info on raid :

http://en.wikipedia.org/wiki/Redundant_array_of_independent_disks

one more general tip: test your setup and find out where the bottlenecks are
before buying new material.

cheers
d

On 4/3/07, Christopher Lowther wrote:
>
>
> So, if I wanted to run 3 Quicktime movies that are about 10 minutes
> apiece…no fancy graphics…what configuration of computer would you
> recommend to run this? I need to install something soon and I just want to
> know if I need to order a computer now or try and run it from my Dell PC
> (Dell 8400 Pentium 4 CPU, 3.20 GHz, 3.19 GHz , 1.0 GB RAM, NVIDIA GeForce
> 6800). I fear my machine is not fast enough for this project.
>

#100625
Apr 4, 2007 at 11:24am

This synchronization question ist interesting in many respects. Using buffers synchronized to matrixsets to create loops which have to be sychronized over 5 or 6 minutes, I never had any discernable problem, even though I expected one. As an example, if a loop is one second long, then my playback-rate, governed by a phasor on the audio side, will be very exact. The playback of video, however, reports framerates hovering around but not exactly equal to an even division of a second. Still, I never saw a discernable discrepancy between the audio and video loops. What is the Jitter framerate-report actually telling me?

#100626
Apr 4, 2007 at 12:15pm

Quote: Dart wrote on Tue, 03 April 2007 18:21
—————————————————-
> So, if I wanted to run 3 Quicktime movies that are about 10 minutes apiece…no fancy graphics…what configuration of computer would you recommend to run this? I need to install something soon and I just want to know if I need to order a computer now or try and run it from my Dell PC (Dell 8400 Pentium 4 CPU, 3.20 GHz, 3.19 GHz , 1.0 GB RAM, NVIDIA GeForce 6800). I fear my machine is not fast enough for this project.
—————————————————-

I strongly recommend to try first..

Mattijs

#100627
Apr 4, 2007 at 1:30pm

Ok will do. It should arrive today. I’ve got some test clips to try and see if my machine can handle.

#100628
Apr 4, 2007 at 2:22pm

Quote: Dart wrote on Wed, 04 April 2007 15:30
—————————————————-
> Ok will do. It should arrive today. I’ve got some test clips to try and see if my machine can handle.
>
>
—————————————————-

You can try without the triplehead2go. I am quite sure that if your machine can handle it with one screen, with 3 will work too. The bottleneck doesn’t lie in the graphics card but in the decompression or the hd.

Mattijs

#100629
Apr 6, 2007 at 4:46am

One person suggested creating one movie and letting Matrox separate. Could I bypass the 3 video clip with one movie (I could piece together the 3 movies in After Effects and export as one file)?

#100630
Apr 6, 2007 at 7:13am

>
> One person suggested creating one movie and letting Matrox separate. Could
> I bypass the 3 video clip with one movie (I could piece together the 3
> movies in After Effects and export as one file)?
>

Ofcourse that’s an option. U’ll just have to make sure that you can handle
the datarate for a videoclip that large…

#100631
Apr 6, 2007 at 7:54am

The interface of the Matrix TH2G only allows me to choose games. How do I choose a video?

#100632
Apr 6, 2007 at 8:04am

>
> The interface of the Matrix TH2G only allows me to choose games. How do I
> choose a video?
>

??
Just set the resolution for your ‘TH2G display’ to 2400×600 or something
alike. That should do the trick.

#100633
Apr 6, 2007 at 4:20pm

So I have my matrox, analog because I’m connecting to VGA projectors, and now I need to create an executable file that it recognizes in order to test my computer. Is this correct?

So, the .exe file will be the Jitter file?

Can you give me help in beginning my Jitter code to run 3 video clips?

I’m not quite sure what Jitter term to even look up.

Thank you very much

#100634
Apr 7, 2007 at 10:57am

Honestly, this sounds as if you have no idea at all what you are doing. Did you do the max and jitter tutorials? Support -> Documentation -> Jitter 1.6

Mattijs

Quote: Dart wrote on Fri, 06 April 2007 18:20
—————————————————-
> So I have my matrox, analog because I’m connecting to VGA projectors, and now I need to create an executable file that it recognizes in order to test my computer. Is this correct?
>
> So, the .exe file will be the Jitter file?
>
> Can you give me help in beginning my Jitter code to run 3 video clips?
>
> I’m not quite sure what Jitter term to even look up.
>
> Thank you very much
—————————————————-

#100635
Apr 7, 2007 at 2:31pm

I have very limited experience with Jitter, and I’m extremely bad at anything that involves logic or code. I’m an artist that hasn’t gotten all the coding skills yet.

Sorry, I don’t want to be a pain.

I will go to the tutorial you mentioned.

thanks for your help.

#100636
Apr 7, 2007 at 2:44pm

Ah.. maybe you should have mentioned that in advance. In general it’s not bad practice to access a software forum only after you read the basic documentation, and the advice given you in this thread assumed that you did.

I don’t know of how much use these tips are if you don’t know jitter. I strongly recommend asking someone with a technical background to help you out. Let him do the max and jitter tutorials and then read this thread and you’ll be close to your target.

Good luck,
Mattijs

Quote: Dart wrote on Sat, 07 April 2007 16:31
—————————————————-
> I have very limited experience with Jitter, and I’m extremely bad at anything that involves logic or code. I’m an artist that hasn’t gotten all the coding skills yet.
>
> Sorry, I don’t want to be a pain.
>
> I will go to the tutorial you mentioned.
>
> thanks for your help.
—————————————————-

#100637
Apr 17, 2007 at 11:47pm

I think I have the patch, I saved it and when I opened the Matrox interface it doesn’t detect the jit file.

Any suggestions?

Thanks

#100638
Apr 18, 2007 at 12:05am

I tried the different resolutions offered by Matrox with no luck.

#100639
Apr 18, 2007 at 4:21am

What about this solution:

Create 3 videos made intentionally thinner, load up the matrox and position each video within the window of each projector. When matrox is loaded it’ll stretch the video to it’s normal width.

I have the patch for running 3 videos simultaneously…I could use that to synchronize them, and spread out over 3 monitors. Again, I could create videos that were intentionally thinner.

Is this too low-tech?

#100640
Apr 18, 2007 at 8:18am

Quote: Dart wrote on Wed, 18 April 2007 06:21
—————————————————-
> What about this solution:
>
> Create 3 videos made intentionally thinner, load up the matrox and position each video within the window of each projector. When matrox is loaded it’ll stretch the video to it’s normal width.
>
> I have the patch for running 3 videos simultaneously…I could use that to synchronize them, and spread out over 3 monitors. Again, I could create videos that were intentionally thinner.
>
> Is this too low-tech?
—————————————————-

I think Quicktime adds black borders to the video in full screen mode if the screen resolution doesn’t match the video resolution. What you could do (but seriously, this thread is getting really off topic), is make a quicktime movie of 12 x 3 ratio, with the 3 movies added together side by side in some video editing software, then play that full screen in quicktime on your matrox output.

Good luck,
Mattijs

#100641

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