This covers:
 - Source
 - SourceMedia
 - Interval

Consolidator:
  interface

OverlapConsolidator:
  condenses features if their times overlap

Classes for actually making video files

 - VideoProducer -- interface
 - FfmpegVideoProducer -- make a temporary video using ffmpeg

for jrgillick/laughter-detection to slot into

or at least what passes for an interface in python