          return files
  
      def load_latest_preview(self, thumbnail_size, frame_dims):
          """ Load the latest preview image for extract and convert """
          logger.trace("Loading preview image: (thumbnail_size: %s, frame_dims: %s)",
                       thumbnail_size, frame_dims)
          imagefiles = self.get_images(self.pathoutput)
          if not imagefiles or len(imagefiles) == 1:
              logger.debug("No preview to display")
              self.previewoutput = None
 
</s> remove         if not imagefiles or len(imagefiles) == 1:
 </s> add         gui_preview = os.path.join(self.pathoutput, ".gui_preview.jpg")
        if not imagefiles or (len(imagefiles) == 1 and gui_preview not in imagefiles): </s> remove         logger.trace("Image files: %s", files)
 </s> add         logger.debug("Image files: %s", files) </s> remove             self.previewoutput = None
 </s> add #            self.previewoutput = None </s> remove         logger.trace("Loading Training preview images")
 </s> add         logger.debug("Loading Training preview images") </s> remove         logger.trace("Image Files: %s", len(imagefiles))
        num_images = (frame_dims[0] // thumbnail_size) * (frame_dims[1] // thumbnail_size)
        if num_images > len(imagefiles):
            logger.debug("Not enough images to generate display. (to display: %s, available "
                         "images: %s)", num_images, len(imagefiles))
            self.previewoutput = None
 </s> add         # Filter to just the gui_preview if it exists in folder output
        imagefiles = [gui_preview] if gui_preview in imagefiles else imagefiles
        logger.debug("Image Files: %s", len(imagefiles))

        imagefiles = self.get_newest_filenames(imagefiles)
        if not imagefiles:
        logger.debug("Loading preview image: (thumbnail_size: %s, frame_dims: %s)",
          return files
  
      def load_latest_preview(self, thumbnail_size, frame_dims):
          """ Load the latest preview image for extract and convert """
        logger.debug("Loading preview image: (thumbnail_size: %s, frame_dims: %s)",
                       thumbnail_size, frame_dims)
          imagefiles = self.get_images(self.pathoutput)
          if not imagefiles or len(imagefiles) == 1:
              logger.debug("No preview to display")
              self.previewoutput = None
keep keep keep keep replace keep keep keep keep keep
 GUI: Preview for convert

Display preview when outputting to a stream container (e.g. video, gif) 
lib/gui/utils.py