code: def setpts(stream, expr):
      
      return FilterNode(stream, setpts.__name__, args=[expr]).stream()
docs: Change the PTS (presentation timestamp) of the input frames.
  
      Args:
          expr: The expression which is evaluated for each frame to construct its timestamp.
  
      Official documentation: `setpts, asetpts <https://ffmpeg.org/ffmpeg-filters.html#setpts_002c-asetpts>`__