code: func (w *Webcam) WaitForFrame(timeout uint32) error {
  
  	count, err := waitForFrame(w.fd, timeout)
  
  	if count < 0 || err != nil {
  		return err
  	} else if count == 0 {
  		return new(Timeout)
  	} else {
  		return nil
  	}
  }
docs: // Wait until frame could be read