  
      @property
      def video_fps(self):
          """ Return the fps of source video """
          reader = imageio.get_reader(self.source_video)
          retval = reader.get_meta_data()["fps"]
          reader.close()
          logger.debug(retval)
          return retval
  
 
</s> remove             # retval = imageio.get_reader(self.folder)
 </s> add             # retval = imageio.get_reader(self.folder, "ffmpeg") </s> remove         reader = imageio.get_reader(input_)
 </s> add         reader = imageio.get_reader(input_, "ffmpeg") </s> remove         reader = imageio.get_reader(self.args.input_dir)
 </s> add         reader = imageio.get_reader(self.args.input_dir, "ffmpeg") </s> remove         reader = imageio.get_reader(self.args.input_dir)
 </s> add         reader = imageio.get_reader(self.args.input_dir, "ffmpeg") </s> remove         reader = imageio.get_reader(input_)
 </s> add         reader = imageio.get_reader(input_, "ffmpeg")
        reader = imageio.get_reader(self.source_video, "ffmpeg")
  
      @property
      def video_fps(self):
          """ Return the fps of source video """
        reader = imageio.get_reader(self.source_video, "ffmpeg")
          retval = reader.get_meta_data()["fps"]
          reader.close()
          logger.debug(retval)
          return retval
  
keep keep keep keep replace keep keep keep keep keep
 Force imageio to use ffmpeg 
plugins/convert/writer/ffmpeg.py