void emit_plain_start (dcpomatic::ContentTime from, std::list<dcp::SubtitleString> s);
void emit_plain_start (dcpomatic::ContentTime from, sub::Subtitle const & subtitle);
void emit_plain (dcpomatic::ContentTimePeriod period, std::list<dcp::SubtitleString> s);
void emit_plain (dcpomatic::ContentTimePeriod period, sub::Subtitle const & subtitle);
void emit_stop (dcpomatic::ContentTime to);
void emit_plain_start (dcpomatic::ContentTime from, std::list<dcp::SubtitleString> s);
void emit_plain_start (dcpomatic::ContentTime from, sub::Subtitle const & subtitle);
void emit_plain (dcpomatic::ContentTimePeriod period, std::list<dcp::SubtitleString> s);
void emit_plain (dcpomatic::ContentTimePeriod period, sub::Subtitle const & subtitle);
void emit_stop (dcpomatic::ContentTime to);