int copy(double start, double end, FileXML *xml);
int copy_length(long start, long end); // return number of Labels in selection
Label *add_label(double position);
int copy(double start, double end, FileXML *xml);
int copy_length(long start, long end); // return number of Labels in selection
Label *add_label(double position);
// Get nearest labels or 0 if start or end of timeline
Label* prev_label(double position);
Label* next_label(double position);
// Get nearest labels or 0 if start or end of timeline
Label* prev_label(double position);
Label* next_label(double position);