  
      def get_filename_prefix(self):
          """ Video name needs to be prefixed to filename if input is a
              video and processing frames """
          if self.is_video and self.type == "frames":
              return "{}_".format(os.path.basename(self.source_dir))
          return ""
  
      def output_file(self, output_message, items_discovered):
          """ Save the output to a text file in the frames directory """
          now = datetime.now().strftime("%Y%m%d_%H%M%S")
 
</s> remove     def get_filename_prefix(self):
 </s> add     def _get_filename_prefix(self): </s> remove         if self.is_video and self.type == "frames":
            return os.path.dirname(self.source_dir)
        return self.source_dir
 </s> add         if self._is_video and self._type == "frames":
            return os.path.dirname(self._source_dir)
        return self._source_dir </s> remove         dst_dir = self.get_output_folder()
        filename = "{}{}_{}.txt".format(self.get_filename_prefix(),
 </s> add         dst_dir = self._get_output_folder()
        filename = "{}{}_{}.txt".format(self._get_filename_prefix(), </s> remove     def get_output_folder(self):
 </s> add     def _get_output_folder(self): </s> remove         if self.output == "file":
 </s> add         if self._output == "file":
        if self._is_video and self._type == "frames":
            return "{}_".format(os.path.basename(self._source_dir))
  
      def get_filename_prefix(self):
          """ Video name needs to be prefixed to filename if input is a
              video and processing frames """
        if self._is_video and self._type == "frames":
            return "{}_".format(os.path.basename(self._source_dir))
        if self._is_video and self._type == "frames":
            return "{}_".format(os.path.basename(self._source_dir))
          return ""
  
      def output_file(self, output_message, items_discovered):
          """ Save the output to a text file in the frames directory """
          now = datetime.now().strftime("%Y%m%d_%H%M%S")
keep keep keep keep replace replace keep keep keep keep keep
 Update extracted faces to use PNG EXIF data (#1123)

Documentation
  - Update Usage.md, align.rst and image.rst
lib.image.py
  - read_image - Remove hash return, add metadata return
  - Remove read_image_hash functions
  - Add read_image_meta functios
  - Replace encode_image_with_hash with encode_image (to store metadata)
  - Add png meta reading and writing functions
  - Update Image Loaders/Savers to handle metadata rather than hashes
lib.training_data
  - Naming updates to remove references to hashes
lib.align.Alignments
  - Add versioning notes
  - Increment alignments version to 2.1
  - Deprecate hashing lookup functions
  - Replace filter_hashes with filter_faces
lib.align.detected_face
  - DetectedFace
    - Remove hash property
    - Add png header data serializing/deserializing functions
  - Mask
    - Add png header data serializing/deserializing functions
  - add update_legacy_png_header function to update png meta data
lib.cli.args - Deprecate alignments files for training
- plugins.train.trainer
  - Update alignments/mask code to read png header data
- scripts.convert
  - Aligned images folder - read data from png headers
- scripts.extract
  - Write png header information and no longer store hash of face
- tools.alignments
  - remove leftover-faces, merge and update-hashes jobs
  - Update jobs to use png meta data rather than hashes
- tools.manual
  - Update extract code to output png meta data and don't store hashes
  - Perform check on launch that tool is not pointing at a faces folder
tools.mask
  - Update to use png meta data
tools.sort
  - Update to use png meta data 
tools/alignments/jobs.py