framepos_t frames_from_bbt_string (framepos_t, const std::string&) const;
framepos_t frame_duration_from_bbt_string (framepos_t, const std::string&) const;
framepos_t frames_from_minsec_string (const std::string&) const;
framepos_t frames_from_bbt_string (framepos_t, const std::string&) const;
framepos_t frame_duration_from_bbt_string (framepos_t, const std::string&) const;
framepos_t frames_from_minsec_string (const std::string&) const;