_next = _subtitles.begin ();
list<dcp::SubtitleString>::const_iterator i = _subtitles.begin ();
while (i != _subtitles.end() && ContentTime::from_seconds (_next->in().as_seconds()) < time) {
_next = _subtitles.begin ();
list<dcp::SubtitleString>::const_iterator i = _subtitles.begin ();
while (i != _subtitles.end() && ContentTime::from_seconds (_next->in().as_seconds()) < time) {