+class Region;
+
+/** @class Playlist
+ * @brief A set of content files (video and audio), with knowledge of how they should be arranged into
+ * a DCP.
+ *
+ * This class holds Content objects, and it knows how they should be arranged. At the moment
+ * the ordering is implicit; video content is placed sequentially, and audio content is taken
+ * from the video unless any sound-only files are present. If sound-only files exist, they
+ * are played simultaneously (i.e. they can be split up into multiple files for different channels)
+ */
+
+struct ContentSorter
+{
+ bool operator() (boost::shared_ptr<Content> a, boost::shared_ptr<Content> b);
+};