!7

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

import com.github.sarxos.webcam.Webcam;

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

p {
  time "list webcams" {
    L<Webcam> webcams = new L(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 i, Webcam webcam over webcams: { try {
  	System.out.format("Opening %s\n", webcam.getName());
  	time "Opening webcam" {
  	  webcam.open();
  	}
  } catch e {
    print("Can't open webcam " + webcam.getName() + " - " + silentException(e));
    webcams.remove(i--);
  }}
  
  new L<Pair<S, BufferedImage>> images;
  
  // capture picture from all of them
  for (int i = 0; i < webcams.size(); i++) pcall {
  	Webcam webcam = webcams.get(i);
  	S name = webcam.getName();
  	System.out.format("Capturing %s\n", name);
  	time "Capturing image" {
  	  images.add(pair(name, webcam.getImage()));
  	}
  }
  
  // close all
  time "Closing webcams" {
    for (Webcam webcam : webcams) {
    	System.out.format("Closing %s\n", webcam.getName());
  	  webcam.close();
    }
  }
  
  for (Pair<S, BufferedImage> p : images)
    showImage(p.a, p.b);
}

Began life as a copy of #1008989