constexpr float SPACE_BEFORE_EPSILON = 1e-3;
+constexpr float SIZE_EPSILON = 1e-3;
+constexpr float OFFSET_EPSILON = 1e-3;
+constexpr float SPACING_EPSILON = 1e-3;
+
+
enum class Marker {
FFOC, ///< first frame of composition
LFOC, ///< last frame of composition