Asking hardware advices for installation

  • Hi Izzy users,

    I would like to develop an interactive installation with 7 computer displays, and to make the budget I need some technical advices :

    First, for the computer part, I hesitate between 2 mac mini with SSD (I get 4 thunderbolt outputs, 2 per mac) and 1 mac pro (6 thunderbolt outputs) ; I keep the HDMI output for Izzy interface.

    • Because I need 7 outputs, If I choose the mac mini solution, I have to add 1 Matrox TripleHead (mini DP in / DVI out) to the first computer, and 1 Matrox DualHead (mini DP in / DVI out) to the second one.

    • If I choose the mac pro, I have to add 1 Matrox DualHead (mini DP in / DVI out).

    Which configuration do you think is the best ?

    I would like to play HD movies and I know that Izzy v2 can play 4 at the same time if well encoded, do you think both configurations are appropriate, that is the new mac pro can play 7 HD clip ?

    I would like to be able to change the video on each display by 4 medias (30 seconds max each one), so the patch have to load 7x4 = 28 movies, is there a technical limit ? (I think just the RAM is requested, so 8 or 16 GB should be ok for short movies…)

    And last question, I think to connect displays through DVI, is there an advantage to do it through HDMI ?

    The signal is the same (with standard resolution for HDMI), and the limit wire distance is equal too (between 5 and 10m), but maybe one is better in my case…

    Thanks a lot for any advice.

    All the best.


  • Hello,

     I just made an installation in south of France with 4 HD clips on 1 MacMini (via 2 Matrox DualHead DPtoDVI).
    It worked  well. And you keep the HDMI output for the control.
    So you can easily have 7 output with 2 Mac.
    I encoded it in h264 1920x1080 25p, the four images was synchronized and the 8 soundtracks was on separate file who was the synch master.
    I doesn't tried with the MacPro (out of budget)
    When you say 4 medias by display, you think fade in/out or just cut ? (it change a lot for the load).
    You need to be more precise concerning how it will works, sound? synchro? etc.
    HDMI and DVI are the same, you have cable with both plugs, so lame length, max 20m (depend of screen), good at 10m.
    You can send me a personal message if you want more infos.
    Jacques Hoepffner

  • Bonjour Jacques,

    Thanks a lot for your comment !
    Indeed I would like to make fades in and out on each display, that is the main movie is replaced by 3 others with fades.
    Each movie represents faces and the speech has to be synchronised, so I think I need an audio interface 8 outputs to drive sound to little speakers (or display internal speakers).
    Further sound processing, I have to manage 7 sensor data, one for each display (it may not be a processing problem regarding the resources...)
    So there are several factors to take into consideration, and if the project takes the right way I keep the opportunity to send you a personal message.
    A last question, do you think 2 DualHead is a better solution than 1 native output + 1 TripleHead ?
    Thank you very much, best regards.

  • Bonjour Clement,

    Considering fades, the question is ; the choice is sequential (there is only 2 movies running simultaneously for each display) or randomly?
    In any case it could be a minimum of 8 movies running simultaneously on each computer!
    Perhaps you have to think with an external HD with half of the movies.
    Perhaps you cal try if "half HD" aka 720p it's sufficient quality?
    I made the choice of 2 dual head because it's easier to manage and you have a better output in term of definition for other uses.
    Hope that helps,

  • peut-être vous ou quelqu'un de votre entourage peut-être intéressé:

  • Thanks @jhoepffner for your answer.

    I plan to do fades in a sequential way, that is when the sensor is triggered, movies are played in this order :
    movie 1 (main) > _trigger_ > movie 2 > movie 1    -    _trigger_ > movie 3 > movie 1    -    _trigger_ > movie 4 > movie 1
    I am thinking to make an urn randomization :
    - first trigger : random between movies 2 - 3 - 4  (for ex 3)
    - second trigger : random between the three movies excepted the last played  (3 was played, so random between 2 and 4, for ex 4)
    - third trigger : movie 2 is remaining
    - restart of the random
    But it seems complicated to program, so not sure to succeed.
    Do you think this way involves more resources, more than 14 movies (30s max each one) running for the 7 displays ?
    720p is an alternative, external hard drive too, but even if mac mini are used I would like to customise them with SSD...
    I will talk about the workshop to friends if interested.
    Thanks a lot, all the best.

  • I think it is doable, you can preload the movies and have a good reactivity. The best it's to test it quickly.

    Concerning program, javascript is now a very good option to do that, because you need a global variable to retain what was played, but you can also use data array, who can record on a spreadsheet what was played and make a choice with the information.

  • Thanks again @jhoepffner for your advices.

    I didn't think about javascript and data array, I will look into this options.
    I will keep you inform of the progress and if I find the budget to produce the project.
    All the best.