          if preview:
              raise ValueError("Preview with audio muxing is not supported.")
          # if not preview:
          #    _output_opts = '-y ' + _output_opts
          _inputs = {input_.path: _input_opts, ref_vid.path: _ref_vid_opts}
          _outputs = {output.path: _output_opts}
          Effmpeg.__run_ffmpeg(exe=exe, inputs=_inputs, outputs=_outputs)
  
      @staticmethod
      def slice(input_=None, output=None, start=None, duration=None,
 
</s> remove             _inputs = {_input_path: _input_opts, ref_vid.path: None}
 </s> add             _inputs = OrderedDict([(_input_path, _input_opts), (ref_vid.path, None)]) </s> remove         _output_opts = '-vf fps="' + str(fps) + '" '
 </s> add         _fps_arg = '-r ' + str(fps) + ' '
        _input_opts += _fps_arg + "-f image2 "
        _output_opts = _fps_arg </s> remove                 if (self.command == "train" and self.capture_loss(output)) or (
                        self.command != "train" and self.capture_tqdm(output)):
 </s> add                 if ((self.command == "train" and self.capture_loss(output)) or
                        (self.command == "effmpeg" and self.capture_ffmpeg(output)) or
                        (self.command not in ("train", "effmpeg") and self.capture_tqdm(output))):
        _inputs = OrderedDict([(input_.path, _input_opts), (ref_vid.path, _ref_vid_opts)])
          if preview:
              raise ValueError("Preview with audio muxing is not supported.")
          # if not preview:
          #    _output_opts = '-y ' + _output_opts
        _inputs = OrderedDict([(input_.path, _input_opts), (ref_vid.path, _ref_vid_opts)])
          _outputs = {output.path: _output_opts}
          Effmpeg.__run_ffmpeg(exe=exe, inputs=_inputs, outputs=_outputs)
  
      @staticmethod
      def slice(input_=None, output=None, start=None, duration=None,
keep keep keep keep replace keep keep keep keep keep
 Fix effmpeg fps detection and better GUI handling 
tools/effmpeg.py