void set_transition_length(Transition *transition, double length);
void paste_transitions(double start, double end, int track_type, char* title);
void update_idxbl_length(int id, double dt);
void set_transition_length(Transition *transition, double length);
void paste_transitions(double start, double end, int track_type, char* title);
void update_idxbl_length(int id, double dt);