code: def start_event(self):
          
          # create object pool for each output
          if self.with_outframe_pool:
              self.update_config()
              for name in self.outputs:
                  self.outframe_pool[name] = ObjectPool(
                      Frame, self.new_frame, self.config['outframe_pool_len'])
          try:
              self.on_start()
          except Exception as ex:
              self.logger.exception(ex)
              raise StopIteration()
docs: Called by the event loop when it is started.
  
          Creates the output frame pools (if used) then calls
          :py:meth:`on_start`. Creating the output frame pools now allows
          their size to be configured before starting the component.