!7

lib 1008985 // webcam
lib 1008987 // bridj
lib 1004016 // slf4j api

import com.github.sarxos.webcam.Webcam;

/**
 * @author Bartosz Firyn (SarXos)
 */

p {
  List<Webcam> webcams = Webcam.getWebcams();
  
  // NOTE!
  /*
   * Yes, I know we could do this in one loop, but I wanted to prove here
   * that it's possible to have many native webcams open in the same time.
   * I tested this example with 4 webcams simultaneously connected to the
   * USB bus - 1 x PC embedded device, and 3 x UVC devices connected to
   * the USB concentration hub, which was connected to the USB 2.0 port.
   * It's working like a charm.
   */
  
  // USB BANDWIDTH!
  /*
   * As you probably know the USB has limited bandwidth and therefore it
   * may not be possible to transfer images from as many cameras as you
   * would like to wish. This example works when I'm using QQVGA (176x144)
   * but fails with the error message when I want to fetch VGA (640x480).
   */
  
  // open all at once (this is the most time-consuming operation, all
  // others are executed instantly)
  for (Webcam webcam : webcams) {
  	System.out.format("Opening %s\n", webcam.getName());
  	webcam.open();
  }
  
  // capture picture from all of them
  for (int i = 0; i < webcams.size(); i++) {
  	Webcam webcam = webcams.get(i);
  	System.out.format("Capturing %s\n", webcam.getName());
  	ImageIO.write(webcam.getImage(), "PNG", print(prepareProgramFile(String.format("test-%d.png", i))));
  }
  
  // close all
  for (Webcam webcam : webcams) {
  	System.out.format("Closing %s\n", webcam.getName());
  	webcam.close();
  }
}

See https://github.com/sarxos/webcam-capture