              filename, faces = self.process_single_image(filename)
              self.faces.faces_detected[os.path.basename(filename)] = faces
  
      def extract_multi_process(self):
          """ Run the extraction on the correct number of processes """
          frame_no = 0
 
</s>
            frame_no += 1
            if frame_no == self.save_interval:
                self.write_alignments()
                frame_no = 0
              filename, faces = self.process_single_image(filename)
              self.faces.faces_detected[os.path.basename(filename)] = faces
            frame_no += 1
            if frame_no == self.save_interval:
                self.write_alignments()
                frame_no = 0
  
      def extract_multi_process(self):
          """ Run the extraction on the correct number of processes """
          frame_no = 0
keep add keep keep keep keep
 alignments.json save interval for extracting (#477)

* implement save interval
scripts/extract.py