-void
-render_subtitles (std::list<dcp::SubtitleString>, dcp::Size, boost::shared_ptr<Image> &, Position<int> &);
+std::string marked_up (std::list<SubtitleString> subtitles, int target_height, float fade_factor);
+std::list<PositionImage> render_subtitles (
+ std::list<SubtitleString>, std::list<boost::shared_ptr<Font> > fonts, dcp::Size, DCPTime, int
+ );