+std::istream& operator>>(std::istream& o, ARDOUR::TimecodeFormat& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::DenormalModel& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::WaveformScale& sf);
+std::istream& operator>>(std::istream& o, ARDOUR::WaveformShape& sf);
+
+std::ostream& operator<<(std::ostream& o, const ARDOUR::SampleFormat& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::HeaderFormat& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::AutoConnectOption& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::EditMode& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::MonitorModel& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::RemoteModel& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::ListenPosition& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::LayerModel& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::CrossfadeModel& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::SyncSource& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::ShuttleBehaviour& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::ShuttleUnits& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::TimecodeFormat& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::DenormalModel& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::WaveformScale& sf);
+std::ostream& operator<<(std::ostream& o, const ARDOUR::WaveformShape& sf);
+
+static inline ARDOUR::nframes64_t
+session_frame_to_track_frame (ARDOUR::nframes64_t session_frame, double speed)