+/** Time relative to the start or position of a piece of content in its native frame rate */
+typedef Time<ContentTimeDifferentiator, DCPTimeDifferentiator> ContentTime;
+/** Time relative to the start of the output DCP in its frame rate */
+typedef Time<DCPTimeDifferentiator, ContentTimeDifferentiator> DCPTime;
+
+class ContentTimePeriod
+{
+public:
+ ContentTimePeriod () {}
+
+ ContentTimePeriod (ContentTime f, ContentTime t)
+ : from (f)
+ , to (t)
+ {}
+
+ ContentTime from;
+ ContentTime to;
+
+ ContentTimePeriod operator+ (ContentTime const & o) const {
+ return ContentTimePeriod (from + o, to + o);