title: OpenCV VideoCapture device index / device number
body: <p>I have a python environment (on Windows 10) that uses OpenCV <code>VideoCapture</code> class to connect to multiple usb cameras.</p>
  
  <p>As far as I know, there is no way to identify a specific camera in OpenCV other than the <code>device</code> parameter in the <code>VideoCapture</code> class constructor / <code>open</code> method.</p>
  
  <p>The problem is that the device parameter changes depending on how many cameras are actually connected and to which usb ports.</p>
  
  <p>I want to be able to identify a specific camera and find its "device index" or "camera index" no matter how many cameras are connected and to which usb ports.</p>
  
  <p>Can somebody please suggest a way to achieve that functionality? python code is preferable but C++ will also do.</p>