code: public synchronized final long startCapture() throws V4L4JException{
  		if (state != STATE_STOPPED)
  			throw new StateException("The capture has already been started");
  		
  		// Update our state and start the thread
  		state = STATE_RUNNING;
  		thread = threadFactory.newThread(this);
  		thread.setName(thread.getName() + " - v4l4j push source");
  		thread.start();
  
  		return thread.getId();
  	}
docs: This method instructs this source to start the capture and to push
  to the captured frame to the
  {@link CaptureCallback}.
  @throws StateException if the capture has already been started