- void process_video (boost::weak_ptr<Piece>, boost::shared_ptr<const Image>, Eyes, bool, VideoContent::Frame, Time);
- void process_audio (boost::weak_ptr<Piece>, boost::shared_ptr<const AudioBuffers>, AudioContent::Frame);
- void process_subtitle (boost::weak_ptr<Piece>, boost::shared_ptr<Image>, dcpomatic::Rect<double>, Time, Time);