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Connect 4 USB cameras at one time.



  • Hi. I'd like to connect four usb cams to my brand new Apple MacBook. It only has two usb ports. Two cameras will work with a powered usb hub but the third one doesn't work. Any tips or advice would be greatly appreciated.

    Thank you.
    Daniel


  • Every camera should go to dedicated(separate) USB BUS. Bus is not the same as port.One BUS may have multiple ports - also internal. So what you experience sounds pretty normal. For 4 cameras you need some kind of external device.



  • Thank you for your reply. Can you recommend an external device that could handle this. I only find powered USB hubs when I search online. I'm not sure what hardware I am searching for.



  • You can try hubs (one on each port) and then turn off everything on the bus- bluetooth, wifi etc). Depending on the resolution USB cameras might might work but I have had bad experience especially then extending the cameras, you could better use a quad splitter and a single capture unit- if you are doing tracking this is not such a bad idea as you wont use high resolution anyway and you will get an ok picture. If you dont need the cameras at the same time you can also make or buy a cheap matrix or AV switch and change as you need cameras - this is only for analogue cameras not webcams.



  • I've just done an extremely cheap and dirty method of inputting 4 cameras via a single channel - I've been working with a cctv multiplexer / switcher, allowing me to show 4 video feeds as a quad arrangement on a single PAL stream. This stream comes into izzy and then I use chopper actors to dissect each 1/4 of the image and output as necessary to other parts of the patch. Its crude, and low quality but it is economical.

    cameras > multiplexer > digitizer > izzy > chopper > ?

    depending on your needs and visual quality, this may be a great or terrible approach, but just wanted to put it on the table.

    been using it for this show here
    .



  • I've been working on just this issue, and just had some success after a few weeks of figuring.

    You need 4 different webcams, not the same model. 
      I recommend the Nitro A/V hub which is also a firewire hub (that you can connect to Thunderbold with an adapter.) 
     But I've also got it going with a cheaper Belkin hub.
     You can only have 2 USB webcams per hub. But you can still put other things on the hubs. 
     I am only able to get Isadora to recognize 2 streams in it's live input, but you are able to capture the other streams via Syphon, using Syphon Camera. 
     Other applications, such as MAx/MSP-Jitter and MadMapper,  can for some reason see more webcams than Isadora.
      I know that this is being investigated.  
      So in short, getting the cameras connected to Syphon and then to Isadora works; it's not simply a limitation of the USB bus. 


  • Oh, I forgot:

    The fourth camera comes from Max/msp-Jitter, using syphon. 
    And it's very important the order that the applications are launched:
    Isadora has to "claim" its webcams first BEFORE you launch anything else. 
    I launch my Max/msp-jitter application second
     SyphonCamera will take hold of the unclaimed cams.
    What I find interesting is that this appears to be pretty CPU light once Syphon is invoked. 
    I am working on building a max standalone that will send multiple cams to multiple Syphon streams.   I will share it when it is finished. 


  • Thanks everyone. I learned that by using a powered usb hub and adjusting the quality of the live capture, I can get three cams to work with very good quality. It's working fine for this project.



  • I have been testing Logitech latest HD USB webcams (using the cheapest model which costs £20 in the UK), and they both identify individually in Izzy's Live Capture, despite being same brand and same model. This surprised me, but has been absolutely stable. I haven't tried with four of them... but if you have £80 to test with, let us know if anyone has a good result with four of these?
    thanks
    jamie



  • Hi.

    I have resolved to use 3 webcams for my performance. With two connected to a powered USB hub and one connected to the other USB input on the computer, I can get them to work with very good stability. Whenever I add a fourth camera, Isadora either crashes or it becomes really unstable. I should also say that two of the cameras are connected using 50 foot USB cables. The image is good but I don't need HD results.
    Daniel


  • I have tested 6 cameras through a video surveillance multiplexer, It makes one image with the 6 cameras and has hdmi output. I digitized the hd image and "cut the image" with new mapping features and distributed in the outputs. It works like a charm;



  • Hi Armando,
    What kind of surveillance multiplexer do you use ?
    What "new mapping features" are you using ?

    Best
    Philippe



  • Somebody pointed to this device, which apparently had been used to connect 5 kinects to a MBP: http://www.caldigit.com/thunderboltstation/

    --8

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