customizing video output to a projector

Discussion in 'Mac Programming' started by androidjones, May 24, 2007.

  1. androidjones macrumors newbie

    Joined:
    May 24, 2007
    #1
    hello


    my name is Andrew jones, i recently began a career as a vj making live digital paintings at concerts for djs and projecting the work i create . i use a program called painter x to create the paintings, the challenge im facing is coming up with a way to mirror my laptop screen and the projected image. basically i only want the projector to project a portion of my screen, i am working on a mac book pro , the screen resolution i create at is 1680x1050. ideally i want the projector to project a give or take 1024x768 portion of whats on my screen, this allows me to keep all the nuts and bolts of the toolbars and menu pallets on my laptop screen and the image i create stays within the 1024x768 portion so the audience isn't distracted by the menus and can only see the image im painting.

    is there a program i can instal on my mac that will only send a limited portion of whats on my screen to the projector. currently im using a casio projector that has the option built into the projector tech. im playing allot of big venues around the world and i will have to use house projectors for some of the festivals and cant rely on having my casio,

    i would be so grateful for any advise you could offer me to find a solution to this
    :)


    here are some of the live paintings ive creates so far-

    [​IMG]

    [​IMG]

    [​IMG]
     
  2. Nutter macrumors 6502

    Joined:
    Mar 31, 2005
    Location:
    London, England
    #2
    Amazing paintings!

    Unfortunately, I don't think there's a way of solving this in software. Your Mac's video output is handled by the built-in video card, so there's no way of controlling the frame of the mirrored output.

    If your Mac supports dual displays (rather than just mirroring), and Painter X allows you to open a second window onto the same painting, then you could simply position the second window to fill the projected display, and work to your heart's content on the main display.

    I don't know if Painter X will allow you to open a second window. I know that Photoshop does, so it doesn't seem unlikely.
     
  3. androidjones thread starter macrumors newbie

    Joined:
    May 24, 2007
    #3
    thanks fro your response and information,

    painter does allow me to work on two displays, the challenge is that sometime the projected image is directly behind me , or to the left or right of the stage and i cant get a clear look at it. seeing the image im creating on my laptop monitor is critical for discerning a quality image,

    if there is any third party hardware that could take the signal from my mac, and send a "croped" signal to a projector that would work too. Not sure if such a device exists but im certainly open to the posibility that it does.
     
  4. Nutter macrumors 6502

    Joined:
    Mar 31, 2005
    Location:
    London, England
    #4
    If Painter X allows you to open two windows onto the same canvas, you could have the painting displayed on your laptop's display at the same time as the projected second display.

    If that's not possible, you could try looking for some kind of hardware solution for this. I have no idea what that solution would be, sorry.
     
  5. lazydog macrumors 6502a

    Joined:
    Sep 3, 2005
    Location:
    Cramlington, UK
    #5
    Great images!

    If you don't mind carrying a second monitor around you can alway use a DVI splitter box. This will send the same signal to two displays. This way you would use the Mac in dual display mode as normal but the box would handle sending whatever was on your 2nd display to the projector.

    Have a search on Google for 'DVI splitter'. I did a quick look and came up with this as the first hit http://www.gefen.com/kvm/product.jsp?prod_id=1403


    b e n

    EDIT: Does your laptop have an S-VHS output? If it does then maybe you don't need a splitter box. You can use the DVI output to connect to the 2nd monitor and the S-VHS output to the projector… at least I think this might work.
     
  6. androidjones thread starter macrumors newbie

    Joined:
    May 24, 2007
    #6
    nutter-

    thanks for the idea, Painter will allow two canvases but it wont update both at the same time. i will explore some hardware solutions

    lazydog,
    the splitter is a great idea, carying around another monitor will be tough but its good as a last resort. i will be doing a tour of japan for a month, keeping the gear down to a minimun would be nice .
     
  7. lazydog macrumors 6502a

    Joined:
    Sep 3, 2005
    Location:
    Cramlington, UK
    #7
    You might be able to get rid of the 2nd monitor by using a video-in box. That way you would be able to use a window on your Mac as the 2nd monitor by connecting the S-VHS output of the laptop to the video-in box.
    Have a look for Canopus ADVC-110 on the Apple store.

    The simplest and neatest solution though would be to get some software written for you that updates the contents of one window with the contents of another. I've not done this before but I imagine it would be possible and straight forward.

    b e n

    EDIT: I should add that I have no idea if your laptop will mirror the DV-I and S-VHS outputs at the same time!
     
  8. androidjones thread starter macrumors newbie

    Joined:
    May 24, 2007
    #8
    thats a brilliant idea

    having the video in box great, ...what if if i had the video in box while the set up was mirrored, would i get an infinite feedback loop? whoa that would be pretty trippy;)

    how would one go about getting software that updates the windows like you sugested?


    you guys totaly rock,
     
  9. neut macrumors 68000

    neut

    Joined:
    Nov 27, 2001
    Location:
    here (for now)
    #9
    Excellent work! :)

    Love that Bassnectar sound ... would have been cool to see the show you were painting at.
    _

    I've been searching for something like you described, but ended up finding this same thread ... not too encouraging. It's something I'd love to have as well as live digi-painting is something that I've wanted to set up for quite some time (lots of digital artists around here). I'm really surprised I could not find anything.

    It seems like someone could build an app. in Quartz Composer (it's in your Mac OS X Tiger DVD) to do this very thing, but I don't have any experience with it (though, it maybe something I will get into as I keep running into it lately when looking for specific visual apps). I found this DIY VJ site with a how to video on installing QC if you want to try it out. I may do the same.

    If we can figure this out I'll have start practicing digi-painting again so I can try this out live. Thanks for sharing your paintings! :)

    Holy ****!!! (just visited your site) Your paintings are sick and the living art is amazing! I hope your work is available as prints ...
    _

    peace | neut
     
  10. lazydog macrumors 6502a

    Joined:
    Sep 3, 2005
    Location:
    Cramlington, UK
    #10
    I'd offer to write it as I could use it for another project I have on the 'back burner'. However I don't know off hand what the system calls are to access the screen image and I don't think Apple have released the source code for their Grab application. If anyone reading this has some pointers I'd be happy to follow them through.

    b e n
     
  11. Nutter macrumors 6502

    Joined:
    Mar 31, 2005
    Location:
    London, England
    #11
    I haven't tried this myself, but this code should get the contents of a window into an NSImage:

    Code:
    [[window contentView] lockFocus];
    NSBitmapImageRep *windowImageRep = [[NSBitmapImageRep alloc] initWithFocusedViewRect:[[window contentView] bounds]];
    [[window contentView] unlockFocus];
    NSImage *windowImage = [[NSImage alloc] initWithSize:[[window contentView] bounds].size];
    [windowImage addRepresentation:windowImageRep];
    [windowImageRep release];
    
     
  12. Nutter macrumors 6502

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    Mar 31, 2005
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    London, England
    #12
  13. lazydog macrumors 6502a

    Joined:
    Sep 3, 2005
    Location:
    Cramlington, UK
    #13
    Thanks for the link nutter! I'll have a look at that.

    b e n
     
  14. RedTomato macrumors 68040

    RedTomato

    Joined:
    Mar 4, 2005
    Location:
    .. London ..
    #14
    what model laptop do you have?

    I did a play a couple of years ago where I controlled two projectors from my laptop (powerbook 15'') at the same time. It was no problem at all.

    Projector 1 (high quality) went from my DVI out through a DVI-VGA changer (came free with the laptop, or about £10 from apple shop) to the projector.

    Projector 2 (lower quality) from my S-video port.

    Both projectors mirrored my display. In your case, you could send one cable to a inhouse LCD or CRT monitor.

    another way to do it, if you don;t have two output ports on your laptop - some projectors have an output port, allowing you to chain 2 or more projectors together. Attach a LCD / CRT to the projector's output?
     
  15. jacktherabbit macrumors newbie

    Joined:
    Apr 22, 2009
    #15
    Hi, i searched everywhere in the internet and just want to ask the same quesiton. how can i have a seperated viewer with black background and showing the same content of my workspace, and make that viewer go big through the projector?
     

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