{
MarkerTimeAxis* mta = new MarkerTimeAxis (*this, *this->current_session(), track_canvas, track_name, marked_track) ;
((ImageFrameTimeAxis*)marked_track)->add_marker_time_axis(mta, this) ;
{
MarkerTimeAxis* mta = new MarkerTimeAxis (*this, *this->current_session(), track_canvas, track_name, marked_track) ;
((ImageFrameTimeAxis*)marked_track)->add_marker_time_axis(mta, this) ;