list<ContentTextSubtitle> text = subtitle_decoder->get_text_subtitles (ContentTimePeriod (from, to), starting);
BOOST_FOREACH (ContentTextSubtitle& ts, text) {
BOOST_FOREACH (dcp::SubtitleString& s, ts.subs) {
+ s.set_h_position (s.h_position() + subtitle_content->subtitle_x_offset ());
s.set_v_position (s.v_position() + subtitle_content->subtitle_y_offset ());
float const xs = subtitle_content->subtitle_x_scale();
float const ys = subtitle_content->subtitle_y_scale();