Introduce new time for session-relative frame time, and make source interface capable of handling 64-bit long sessions.

sframes_t is "session frames".  The rules for time stamps are:
 - Anything relative to transport time, session position, etc, should be sframes_t
 - Anything relative to jack cycles, including the length thereof, should be nframes_t

To support sessions which exceed UINT32_MAX frames, we need to replace all the uses of
nframes_t for session time with sframes_t, and make sure the conversions are sound.
This does not depend on jack's nframes_t; that we are using the same type at all right now was an oops.

This is also be kinda nice for readability since the two different time bases have different types...


git-svn-id: svn://localhost/ardour2/branches/3.0@4636 d708f5d6-7413-0410-9779-e7cbd77b26cf

18 files changed, 101 insertions, 92 deletions

diff --git a/gtk2_ardour/automation_line.cc b/gtk2_ardour/automation_line.cc
index ad32290a6b..d141bafad1 100644
--- a/gtk2_ardour/automation_line.cc
+++ b/gtk2_ardour/automation_line.cc
@@ -56,11 +56,11 @@ using namespace PBD;
 using namespace Editing;
 using namespace Gnome; // for Canvas
 
-static const Evoral::IdentityConverter<double, nframes_t> default_converter;
+static const Evoral::IdentityConverter<double, sframes_t> default_converter;
 
 AutomationLine::AutomationLine (const string& name, TimeAxisView& tv, ArdourCanvas::Group& parent,
 		boost::shared_ptr<AutomationList> al,
-		const Evoral::TimeConverter<double, nframes_t>* converter)
+		const Evoral::TimeConverter<double, sframes_t>* converter)
 	: trackview (tv)
 	, _name (name)
 	, alist (al)
diff --git a/gtk2_ardour/automation_line.h b/gtk2_ardour/automation_line.h
index 342b8ba2a0..5e1f5b6af0 100644
--- a/gtk2_ardour/automation_line.h
+++ b/gtk2_ardour/automation_line.h
@@ -36,6 +36,7 @@
 #include <pbd/statefuldestructible.h> 
 
 #include <ardour/automation_list.h>
+#include <ardour/types.h>
 
 class AutomationLine;
 class ControlPoint;
@@ -56,7 +57,7 @@ class AutomationLine : public sigc::trackable, public PBD::StatefulThingWithGoin
   public:
 	AutomationLine (const string& name, TimeAxisView&, ArdourCanvas::Group&,
 			boost::shared_ptr<ARDOUR::AutomationList>,
-			const Evoral::TimeConverter<double, nframes_t>* converter = 0);
+			const Evoral::TimeConverter<double, ARDOUR::sframes_t>* converter = 0);
 	virtual ~AutomationLine ();
 
 	void queue_reset ();
@@ -183,8 +184,8 @@ class AutomationLine : public sigc::trackable, public PBD::StatefulThingWithGoin
 	int64_t  drag_x;
 	int64_t  drag_distance;
 
-	const Evoral::TimeConverter<double, nframes_t>& _time_converter;
-	ARDOUR::AutomationList::InterpolationStyle      _interpolation;
+	const Evoral::TimeConverter<double, ARDOUR::sframes_t>& _time_converter;
+	ARDOUR::AutomationList::InterpolationStyle              _interpolation;
 
 	void modify_view_point (ControlPoint&, double, double, bool with_push);
 	void reset_line_coords (ControlPoint&);
diff --git a/libs/ardour/ardour/audiofilesource.h b/libs/ardour/ardour/audiofilesource.h
index 2b59de63ca..0d5f888dd8 100644
--- a/libs/ardour/ardour/audiofilesource.h
+++ b/libs/ardour/ardour/audiofilesource.h
@@ -58,13 +58,13 @@ public:
 	/* this block of methods do nothing for regular file sources, but are significant
 	   for files used in destructive recording.
 	*/
-	virtual nframes_t last_capture_start_frame() const { return 0; }
-	virtual void      mark_capture_start (nframes_t) {}
+	virtual sframes_t last_capture_start_frame() const { return 0; }
+	virtual void      mark_capture_start (sframes_t) {}
 	virtual void      mark_capture_end () {}
 	virtual void      clear_capture_marks() {}
 	virtual bool      one_of_several_channels () const { return false; }
 
-	virtual int update_header (nframes_t when, struct tm&, time_t) = 0;
+	virtual int update_header (sframes_t when, struct tm&, time_t) = 0;
 	virtual int flush_header () = 0;
 
 	void mark_streaming_write_completed ();
diff --git a/libs/ardour/ardour/audiosource.h b/libs/ardour/ardour/audiosource.h
index 740d9bc7c4..0ed621c6ac 100644
--- a/libs/ardour/ardour/audiosource.h
+++ b/libs/ardour/ardour/audiosource.h
@@ -65,7 +65,7 @@ class AudioSource : virtual public Source,
 		return read (dst, (nframes_t) start, (nframes_t) cnt);
 	}
 
-	virtual nframes_t read (Sample *dst, nframes_t start, nframes_t cnt) const;
+	virtual nframes_t read (Sample *dst, sframes_t start, nframes_t cnt) const;
 	virtual nframes_t write (Sample *src, nframes_t cnt);
 
 	virtual float sample_rate () const = 0;
@@ -81,7 +81,7 @@ class AudioSource : virtual public Source,
 	uint32_t write_data_count() const { return _write_data_count; }
 
  	int read_peaks (PeakData *peaks, nframes_t npeaks,
-			nframes_t start, nframes_t cnt, double samples_per_visual_peak) const;
+			sframes_t start, nframes_t cnt, double samples_per_visual_peak) const;
 
  	int  build_peaks ();
 	bool peaks_ready (sigc::slot<void>, sigc::connection&) const;
@@ -126,23 +126,23 @@ class AudioSource : virtual public Source,
 
 	int initialize_peakfile (bool newfile, Glib::ustring path);
 	int build_peaks_from_scratch ();
-	int compute_and_write_peaks (Sample* buf, nframes_t first_frame, nframes_t cnt,
+	int compute_and_write_peaks (Sample* buf, sframes_t first_frame, nframes_t cnt,
 			bool force, bool intermediate_peaks_ready_signal);
 	void truncate_peakfile();
 
 	mutable off_t _peak_byte_max; // modified in compute_and_write_peak()
 
-	virtual nframes_t read_unlocked (Sample *dst, nframes_t start, nframes_t cnt) const = 0;
+	virtual nframes_t read_unlocked (Sample *dst, sframes_t start, nframes_t cnt) const = 0;
 	virtual nframes_t write_unlocked (Sample *dst, nframes_t cnt) = 0;
 	virtual Glib::ustring peak_path(Glib::ustring audio_path) = 0;
 	virtual Glib::ustring find_broken_peakfile (Glib::ustring missing_peak_path,
 	                                            Glib::ustring audio_path) = 0;
 	
  	virtual int read_peaks_with_fpp (PeakData *peaks,
-			nframes_t npeaks, nframes_t start, nframes_t cnt, 
+			nframes_t npeaks, sframes_t start, nframes_t cnt, 
 			double samples_per_visual_peak, nframes_t fpp) const;
 
-	int compute_and_write_peaks (Sample* buf, nframes_t first_frame, nframes_t cnt,
+	int compute_and_write_peaks (Sample* buf, sframes_t first_frame, nframes_t cnt,
 			bool force, bool intermediate_peaks_ready_signal, nframes_t frames_per_peak);	
 
   private:
diff --git a/libs/ardour/ardour/beats_frames_converter.h b/libs/ardour/ardour/beats_frames_converter.h
index 79972cb4c5..e612830ce9 100644
--- a/libs/ardour/ardour/beats_frames_converter.h
+++ b/libs/ardour/ardour/beats_frames_converter.h
@@ -29,22 +29,22 @@ namespace ARDOUR {
 
 class Session;
 
-class BeatsFramesConverter : public Evoral::TimeConverter<double,nframes_t> {
+class BeatsFramesConverter : public Evoral::TimeConverter<double,sframes_t> {
 public:
-	BeatsFramesConverter(Session& session, nframes_t origin)
+	BeatsFramesConverter(Session& session, sframes_t origin)
 		: _session(session)
 		, _origin(origin)
 	{}
 	
-	nframes_t to(double beats)       const;
-	double    from(nframes_t frames) const;
+	sframes_t to(double beats)       const;
+	double    from(sframes_t frames) const;
 
-	nframes_t origin() const              { return _origin; }
-	void     set_origin(nframes_t origin) { _origin = origin; }
+	sframes_t origin() const              { return _origin; }
+	void     set_origin(sframes_t origin) { _origin = origin; }
 
 private:
 	Session&  _session;
-	nframes_t _origin;
+	sframes_t _origin;
 };
 
 } /* namespace ARDOUR */
diff --git a/libs/ardour/ardour/midi_source.h b/libs/ardour/ardour/midi_source.h
index 1b2188e8dd..ec454803dc 100644
--- a/libs/ardour/ardour/midi_source.h
+++ b/libs/ardour/ardour/midi_source.h
@@ -57,20 +57,20 @@ class MidiSource : virtual public Source
 	 * \param negative_stamp_offset Offset to subtract from event times written to dst
 	 */
 	virtual nframes_t midi_read (MidiRingBuffer<nframes_t>& dst,
-			nframes_t position,
-			nframes_t start, nframes_t cnt,
-			nframes_t stamp_offset, nframes_t negative_stamp_offset) const;
+			sframes_t position,
+			sframes_t start, nframes_t cnt,
+			sframes_t stamp_offset, sframes_t negative_stamp_offset) const;
 
 	virtual nframes_t midi_write (MidiRingBuffer<nframes_t>& src,
-			nframes_t position,
+			sframes_t position,
 			nframes_t cnt);
 
 	virtual void append_event_unlocked_beats(const Evoral::Event<double>& ev) = 0;
 
 	virtual void append_event_unlocked_frames(const Evoral::Event<nframes_t>& ev,
-			nframes_t position) = 0;
+			sframes_t position) = 0;
 
-	virtual void mark_streaming_midi_write_started (NoteMode mode, nframes_t start_time);
+	virtual void mark_streaming_midi_write_started (NoteMode mode, sframes_t start_time);
 	virtual void mark_streaming_write_started ();
 	virtual void mark_streaming_write_completed ();
 	
@@ -85,7 +85,7 @@ class MidiSource : virtual public Source
 	static sigc::signal<void,MidiSource*> MidiSourceCreated;
 	       
 	// Signal a range of recorded data is available for reading from model()
-	mutable sigc::signal<void,nframes_t,nframes_t> ViewDataRangeReady;
+	mutable sigc::signal<void,sframes_t,nframes_t> ViewDataRangeReady;
 	
 	XMLNode& get_state ();
 	int set_state (const XMLNode&);
@@ -110,12 +110,12 @@ class MidiSource : virtual public Source
 	virtual void flush_midi() = 0;
 	
 	virtual nframes_t read_unlocked (MidiRingBuffer<nframes_t>& dst,
-			nframes_t position,
-			nframes_t start, nframes_t cnt,
-			nframes_t stamp_offset, nframes_t negative_stamp_offset) const = 0;
+			sframes_t position,
+			sframes_t start, nframes_t cnt,
+			sframes_t stamp_offset, sframes_t negative_stamp_offset) const = 0;
 
 	virtual nframes_t write_unlocked (MidiRingBuffer<nframes_t>& dst,
-			nframes_t position,
+			sframes_t position,
 			nframes_t cnt) = 0;
 	
 	std::string         _captured_for;
@@ -126,7 +126,7 @@ class MidiSource : virtual public Source
 	bool                         _writing;
 	
 	mutable Evoral::Sequence<double>::const_iterator _model_iter;
-	mutable nframes_t                                _last_read_end;
+	mutable sframes_t                                _last_read_end;
 
   private:
 	bool file_changed (std::string path);
diff --git a/libs/ardour/ardour/silentfilesource.h b/libs/ardour/ardour/silentfilesource.h
index ad433e5f94..58460b9c21 100644
--- a/libs/ardour/ardour/silentfilesource.h
+++ b/libs/ardour/ardour/silentfilesource.h
@@ -27,7 +27,7 @@ namespace ARDOUR {
 
 class SilentFileSource : public AudioFileSource {
 public:
-	int update_header (nframes_t when, struct tm&, time_t) { return 0; }
+	int update_header (sframes_t when, struct tm&, time_t) { return 0; }
 	int flush_header () { return 0; }
 	float sample_rate () const { return _sample_rate; }
 
@@ -47,7 +47,7 @@ protected:
 		_length = len;
 	}
 
-	nframes_t read_unlocked (Sample *dst, nframes_t start, nframes_t cnt) const {
+	nframes_t read_unlocked (Sample *dst, sframes_t start, nframes_t cnt) const {
 		memset (dst, 0, sizeof (Sample) * cnt);
 		return cnt;
 	}
@@ -56,7 +56,7 @@ protected:
 
 	void set_header_timeline_position () {}
 
- 	int read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, nframes_t start, nframes_t cnt,
+ 	int read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, sframes_t start, nframes_t cnt,
 			double samples_per_unit, nframes_t fpp) const {
 		memset (peaks, 0, sizeof (PeakData) * npeaks);
 		return 0;
diff --git a/libs/ardour/ardour/smf_source.h b/libs/ardour/ardour/smf_source.h
index 7942a118af..e61b3f9737 100644
--- a/libs/ardour/ardour/smf_source.h
+++ b/libs/ardour/ardour/smf_source.h
@@ -52,9 +52,9 @@ public:
 	bool set_name (const std::string& newname) { return (set_source_name(newname, false) == 0); }
 	
 	void append_event_unlocked_beats (const Evoral::Event<double>& ev);
-	void append_event_unlocked_frames (const Evoral::Event<nframes_t>& ev, nframes_t position);
+	void append_event_unlocked_frames (const Evoral::Event<nframes_t>& ev, sframes_t position);
 
-	void mark_streaming_midi_write_started (NoteMode mode, nframes_t start_time);
+	void mark_streaming_midi_write_started (NoteMode mode, sframes_t start_time);
 	void mark_streaming_write_completed ();
 
 	XMLNode& get_state ();
@@ -71,20 +71,20 @@ public:
 
 private:
 	nframes_t read_unlocked (MidiRingBuffer<nframes_t>& dst,
-			nframes_t position,
-			nframes_t start,
+			sframes_t position,
+			sframes_t start,
 			nframes_t cnt,
-			nframes_t stamp_offset,
-			nframes_t negative_stamp_offset) const;
+			sframes_t stamp_offset,
+			sframes_t negative_stamp_offset) const;
 
 	nframes_t write_unlocked (MidiRingBuffer<nframes_t>& src,
-			nframes_t position,
+			sframes_t position,
 			nframes_t cnt);
 
 	void set_default_controls_interpolation ();
 
 	double    _last_ev_time_beats;
-	nframes_t _last_ev_time_frames;
+	sframes_t _last_ev_time_frames;
 };
 
 }; /* namespace ARDOUR */
diff --git a/libs/ardour/ardour/sndfilesource.h b/libs/ardour/ardour/sndfilesource.h
index 5154a7a80c..66544eec8c 100644
--- a/libs/ardour/ardour/sndfilesource.h
+++ b/libs/ardour/ardour/sndfilesource.h
@@ -43,13 +43,13 @@ class SndFileSource : public AudioFileSource {
 	~SndFileSource ();
 
 	float sample_rate () const;
-	int update_header (nframes_t when, struct tm&, time_t);
+	int update_header (sframes_t when, struct tm&, time_t);
 	int flush_header ();
 
-	nframes_t natural_position () const;
+	sframes_t natural_position () const;
 
-	nframes_t last_capture_start_frame() const;
-	void mark_capture_start (nframes_t);
+	sframes_t last_capture_start_frame() const;
+	void mark_capture_start (sframes_t);
 	void mark_capture_end ();
 	void clear_capture_marks();
 
@@ -65,10 +65,10 @@ class SndFileSource : public AudioFileSource {
   protected:
 	void set_header_timeline_position ();
 
-	nframes_t read_unlocked (Sample *dst, nframes_t start, nframes_t cnt) const;
+	nframes_t read_unlocked (Sample *dst, sframes_t start, nframes_t cnt) const;
 	nframes_t write_unlocked (Sample *dst, nframes_t cnt);
 
-	nframes_t write_float (Sample* data, nframes_t pos, nframes_t cnt);
+	nframes_t write_float (Sample* data, sframes_t pos, nframes_t cnt);
 
   private:
 	SNDFILE *sf;
@@ -77,7 +77,7 @@ class SndFileSource : public AudioFileSource {
 
 	void init_sndfile ();
 	int open();
-	int setup_broadcast_info (nframes_t when, struct tm&, time_t);
+	int setup_broadcast_info (sframes_t when, struct tm&, time_t);
 
 	/* destructive */
 
@@ -87,8 +87,8 @@ class SndFileSource : public AudioFileSource {
 
 	bool          _capture_start;
 	bool          _capture_end;
-	nframes_t      capture_start_frame;
-	nframes_t      file_pos; // unit is frames
+	sframes_t      capture_start_frame;
+	sframes_t      file_pos; // unit is frames
 	nframes_t      xfade_out_count;
 	nframes_t      xfade_in_count;
 	Sample*        xfade_buf;
diff --git a/libs/ardour/ardour/source.h b/libs/ardour/ardour/source.h
index dd86ebe521..36d7e1fe96 100644
--- a/libs/ardour/ardour/source.h
+++ b/libs/ardour/ardour/source.h
@@ -61,11 +61,11 @@ class Source : public SessionObject, public boost::noncopyable
 	time_t timestamp() const { return _timestamp; }
 	void stamp (time_t when) { _timestamp = when; }
 	
-	nframes_t length() const { return _length; }
+	sframes_t length() const { return _length; }
 	
 	virtual const Glib::ustring& path() const = 0;
 
-	virtual nframes_t natural_position() const { return 0; }
+	virtual sframes_t natural_position() const { return 0; }
 
 	void mark_for_remove();
 	
@@ -104,7 +104,7 @@ class Source : public SessionObject, public boost::noncopyable
 	std::string get_transients_path() const;
 	int load_transients (const std::string&);
 	
-	void update_length (nframes_t pos, nframes_t cnt);
+	void update_length (sframes_t pos, sframes_t cnt);
 	
 	int64_t timeline_position() const { return _timeline_position; }
 	virtual void set_timeline_position (int64_t pos);
@@ -118,7 +118,7 @@ class Source : public SessionObject, public boost::noncopyable
 	DataType            _type;
 	Flag                _flags;
 	time_t              _timestamp;
-	nframes_t           _length;
+	sframes_t           _length;
 	int64_t             _timeline_position;
 	bool                _analysed;
 	mutable Glib::Mutex _lock;
diff --git a/libs/ardour/ardour/types.h b/libs/ardour/ardour/types.h
index bbdf0da1d6..264d0666a7 100644
--- a/libs/ardour/ardour/types.h
+++ b/libs/ardour/ardour/types.h
@@ -60,6 +60,13 @@ namespace ARDOUR {
 	typedef uint64_t                    microseconds_t;
 	typedef uint32_t                    nframes_t;
 
+	/** "Session frames", frames relative to the session timeline.
+	 * Everything related to transport position etc. should be of this type.
+	 * We might want to make this a compile time option for 32-bitters who
+	 * don't want to pay for extremely long session times they don't need...
+	 */
+	typedef int64_t sframes_t;
+
 	enum IOChange {
 		NoChange = 0,
 		ConfigurationChanged = 0x1,
@@ -75,7 +82,7 @@ namespace ARDOUR {
 	};
 
 	OverlapType coverage (nframes_t start_a, nframes_t end_a,
-			      nframes_t start_b, nframes_t end_b);
+	                      nframes_t start_b, nframes_t end_b);
 
 	/** See parameter.h
 	 * XXX: I don't think/hope these hex values matter anymore.
diff --git a/libs/ardour/audiosource.cc b/libs/ardour/audiosource.cc
index 7b56d1891e..a25a2dc8ab 100644
--- a/libs/ardour/audiosource.cc
+++ b/libs/ardour/audiosource.cc
@@ -247,7 +247,7 @@ AudioSource::initialize_peakfile (bool newfile, ustring audio_path)
 }
 
 nframes_t
-AudioSource::read (Sample *dst, nframes_t start, nframes_t cnt) const
+AudioSource::read (Sample *dst, sframes_t start, nframes_t cnt) const
 {
 	Glib::Mutex::Lock lm (_lock);
 	return read_unlocked (dst, start, cnt);
@@ -261,13 +261,13 @@ AudioSource::write (Sample *dst, nframes_t cnt)
 }
 
 int
-AudioSource::read_peaks (PeakData *peaks, nframes_t npeaks, nframes_t start, nframes_t cnt, double samples_per_visual_peak) const
+AudioSource::read_peaks (PeakData *peaks, nframes_t npeaks, sframes_t start, nframes_t cnt, double samples_per_visual_peak) const
 {
 	return read_peaks_with_fpp (peaks, npeaks, start, cnt, samples_per_visual_peak, _FPP);
 }
 
 int 
-AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, nframes_t start, nframes_t cnt, 
+AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, sframes_t start, nframes_t cnt, 
 				  double samples_per_visual_peak, nframes_t samples_per_file_peak) const
 {
 	Glib::Mutex::Lock lm (_lock);
@@ -426,7 +426,7 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, nframes_t s
 			if (i == stored_peaks_read) {
 
 				uint32_t       start_byte = current_stored_peak * sizeof(PeakData);
-				tnp = min ((_length/samples_per_file_peak - current_stored_peak), (nframes_t) expected_peaks);
+				tnp = min ((nframes_t)(_length/samples_per_file_peak - current_stored_peak), (nframes_t) expected_peaks);
 				to_read = min (chunksize, tnp);
 				
 #ifdef DEBUG_READ_PEAKS
@@ -520,7 +520,7 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, nframes_t npeaks, nframes_t s
 
 			if (i == frames_read) {
 				
-				to_read = min (chunksize, (_length - current_frame));
+				to_read = min (chunksize, nframes_t(_length - current_frame));
 
 				if (to_read == 0) {
 					/* XXX ARGH .. out by one error ... need to figure out why this happens
@@ -681,14 +681,15 @@ AudioSource::done_with_peakfile_writes (bool done)
 }
 
 int
-AudioSource::compute_and_write_peaks (Sample* buf, nframes_t first_frame, nframes_t cnt, bool force, bool intermediate_peaks_ready)
+AudioSource::compute_and_write_peaks (Sample* buf, sframes_t first_frame, nframes_t cnt,
+		bool force, bool intermediate_peaks_ready)
 {
 	return compute_and_write_peaks (buf, first_frame, cnt, force, intermediate_peaks_ready, _FPP);
 }
 
 int
-AudioSource::compute_and_write_peaks (Sample* buf, nframes_t first_frame, nframes_t cnt, bool force, 
-				      bool intermediate_peaks_ready, nframes_t fpp)
+AudioSource::compute_and_write_peaks (Sample* buf, sframes_t first_frame, nframes_t cnt,
+		bool force, bool intermediate_peaks_ready, nframes_t fpp)
 {
 	Sample* buf2 = 0;
 	nframes_t to_do;
diff --git a/libs/ardour/beats_frames_converter.cc b/libs/ardour/beats_frames_converter.cc
index 736068e690..d6f7ab8a9e 100644
--- a/libs/ardour/beats_frames_converter.cc
+++ b/libs/ardour/beats_frames_converter.cc
@@ -26,7 +26,7 @@
 
 namespace ARDOUR {
 
-nframes_t
+sframes_t
 BeatsFramesConverter::to(double beats) const
 {
 	// FIXME: assumes tempo never changes after origin
@@ -39,7 +39,7 @@ BeatsFramesConverter::to(double beats) const
 }
 
 double
-BeatsFramesConverter::from(nframes_t frames) const
+BeatsFramesConverter::from(sframes_t frames) const
 {
 	// FIXME: assumes tempo never changes after origin
 	const Tempo& tempo = _session.tempo_map().tempo_at(_origin);
diff --git a/libs/ardour/midi_source.cc b/libs/ardour/midi_source.cc
index b9f7776df8..bb5179d2bb 100644
--- a/libs/ardour/midi_source.cc
+++ b/libs/ardour/midi_source.cc
@@ -108,9 +108,9 @@ MidiSource::invalidate ()
 }
 
 nframes_t
-MidiSource::midi_read (MidiRingBuffer<nframes_t>& dst, nframes_t position,
-		nframes_t start, nframes_t cnt,
-		nframes_t stamp_offset, nframes_t negative_stamp_offset) const
+MidiSource::midi_read (MidiRingBuffer<nframes_t>& dst, sframes_t position,
+		sframes_t start, nframes_t cnt,
+		sframes_t stamp_offset, sframes_t negative_stamp_offset) const
 {
 	Glib::Mutex::Lock lm (_lock);
 
@@ -147,7 +147,7 @@ MidiSource::midi_read (MidiRingBuffer<nframes_t>& dst, nframes_t position,
 }
 
 nframes_t
-MidiSource::midi_write (MidiRingBuffer<nframes_t>& dst, nframes_t position, nframes_t cnt)
+MidiSource::midi_write (MidiRingBuffer<nframes_t>& dst, sframes_t position, nframes_t cnt)
 {
 	Glib::Mutex::Lock lm (_lock);
 	return write_unlocked (dst, position, cnt);
@@ -164,7 +164,7 @@ MidiSource::file_changed (string path)
 }
 
 void
-MidiSource::mark_streaming_midi_write_started (NoteMode mode, nframes_t start_frame)
+MidiSource::mark_streaming_midi_write_started (NoteMode mode, sframes_t start_frame)
 {
 	set_timeline_position(start_frame);
 
diff --git a/libs/ardour/region.cc b/libs/ardour/region.cc
index 018e19d60b..70e9eba9ba 100644
--- a/libs/ardour/region.cc
+++ b/libs/ardour/region.cc
@@ -1544,7 +1544,7 @@ Region::verify_length (nframes_t len)
 	nframes_t maxlen = 0;
 
 	for (uint32_t n=0; n < _sources.size(); ++n) {
-		maxlen = max (maxlen, _sources[n]->length() - _start);
+		maxlen = max (maxlen, (nframes_t)_sources[n]->length() - _start);
 	}
 	
 	len = min (len, maxlen);
@@ -1562,7 +1562,7 @@ Region::verify_start_and_length (nframes_t new_start, nframes_t& new_length)
 	nframes_t maxlen = 0;
 
 	for (uint32_t n=0; n < _sources.size(); ++n) {
-		maxlen = max (maxlen, _sources[n]->length() - new_start);
+		maxlen = max (maxlen, (nframes_t)_sources[n]->length() - new_start);
 	}
 
 	new_length = min (new_length, maxlen);
diff --git a/libs/ardour/smf_source.cc b/libs/ardour/smf_source.cc
index 128acca742..7e707b1821 100644
--- a/libs/ardour/smf_source.cc
+++ b/libs/ardour/smf_source.cc
@@ -95,9 +95,9 @@ SMFSource::~SMFSource ()
 
 /** All stamps in audio frames */
 nframes_t
-SMFSource::read_unlocked (MidiRingBuffer<nframes_t>& dst, nframes_t position,
-		nframes_t start, nframes_t dur,
-		nframes_t stamp_offset, nframes_t negative_stamp_offset) const
+SMFSource::read_unlocked (MidiRingBuffer<nframes_t>& dst, sframes_t position,
+		sframes_t start, nframes_t dur,
+		sframes_t stamp_offset, sframes_t negative_stamp_offset) const
 {
 	int      ret  = 0;
 	uint64_t time = 0; // in SMF ticks, 1 tick per _ppqn
@@ -146,7 +146,7 @@ SMFSource::read_unlocked (MidiRingBuffer<nframes_t>& dst, nframes_t position,
 		ev_type = EventTypeMap::instance().midi_event_type(ev_buffer[0]);
 
 		assert(time >= start_ticks);
-		const nframes_t ev_frame_time = converter.to(time / (double)ppqn()) + stamp_offset;
+		const sframes_t ev_frame_time = converter.to(time / (double)ppqn()) + stamp_offset;
 
 		if (ev_frame_time < start + dur) {
 			dst.write(ev_frame_time - negative_stamp_offset, ev_type, ev_size, ev_buffer);
@@ -167,7 +167,7 @@ SMFSource::read_unlocked (MidiRingBuffer<nframes_t>& dst, nframes_t position,
 
 /** All stamps in audio frames */
 nframes_t
-SMFSource::write_unlocked (MidiRingBuffer<nframes_t>& src, nframes_t position, nframes_t dur)
+SMFSource::write_unlocked (MidiRingBuffer<nframes_t>& src, sframes_t position, nframes_t dur)
 {
 	_write_data_count = 0;
 		
@@ -227,7 +227,7 @@ SMFSource::write_unlocked (MidiRingBuffer<nframes_t>& src, nframes_t position, n
 	Evoral::SMF::flush();
 	free(buf);
 
-	const nframes_t oldlen = _length;
+	const sframes_t oldlen = _length;
 	update_length(oldlen, dur);
 
 	ViewDataRangeReady(position + oldlen, dur); /* EMIT SIGNAL */
@@ -269,7 +269,7 @@ SMFSource::append_event_unlocked_beats (const Evoral::Event<double>& ev)
 
 /** Append an event with a timestamp in frames (nframes_t) */
 void
-SMFSource::append_event_unlocked_frames (const Evoral::Event<nframes_t>& ev, nframes_t position)
+SMFSource::append_event_unlocked_frames (const Evoral::Event<nframes_t>& ev, sframes_t position)
 {
 	if (ev.size() == 0)  {
 		return;
@@ -287,7 +287,7 @@ SMFSource::append_event_unlocked_frames (const Evoral::Event<nframes_t>& ev, nfr
 	
 	BeatsFramesConverter converter(_session, position);
 	
-	const nframes_t delta_time_frames = ev.time() - _last_ev_time_frames;
+	const sframes_t delta_time_frames = ev.time() - _last_ev_time_frames;
 	const double    delta_time_beats  = converter.from(delta_time_frames);
 	const uint32_t  delta_time_ticks  = (uint32_t)(lrint(delta_time_beats * (double)ppqn()));
 
@@ -329,7 +329,7 @@ SMFSource::set_state (const XMLNode& node)
 }
 
 void
-SMFSource::mark_streaming_midi_write_started (NoteMode mode, nframes_t start_frame)
+SMFSource::mark_streaming_midi_write_started (NoteMode mode, sframes_t start_frame)
 {
 	MidiSource::mark_streaming_midi_write_started (mode, start_frame);
 	Evoral::SMF::begin_write ();
diff --git a/libs/ardour/sndfilesource.cc b/libs/ardour/sndfilesource.cc
index d651d40970..f759653e58 100644
--- a/libs/ardour/sndfilesource.cc
+++ b/libs/ardour/sndfilesource.cc
@@ -274,7 +274,7 @@ SndFileSource::sample_rate () const
 }
 
 nframes_t
-SndFileSource::read_unlocked (Sample *dst, nframes_t start, nframes_t cnt) const
+SndFileSource::read_unlocked (Sample *dst, sframes_t start, nframes_t cnt) const
 {
 	int32_t nread;
 	float *ptr;
@@ -482,7 +482,7 @@ SndFileSource::destructive_write_unlocked (Sample* data, nframes_t cnt)
 }
 
 int
-SndFileSource::update_header (nframes_t when, struct tm& now, time_t tnow)
+SndFileSource::update_header (sframes_t when, struct tm& now, time_t tnow)
 {	
 	set_timeline_position (when);
 
@@ -506,7 +506,7 @@ SndFileSource::flush_header ()
 }
 
 int
-SndFileSource::setup_broadcast_info (nframes_t when, struct tm& now, time_t tnow)
+SndFileSource::setup_broadcast_info (sframes_t when, struct tm& now, time_t tnow)
 {
 	if (!writable()) {
 		warning << string_compose (_("attempt to store broadcast info in a non-writable audio file source (%1)"), _path) << endmsg;
@@ -556,7 +556,7 @@ SndFileSource::set_header_timeline_position ()
 }
 
 nframes_t
-SndFileSource::write_float (Sample* data, nframes_t frame_pos, nframes_t cnt)
+SndFileSource::write_float (Sample* data, sframes_t frame_pos, nframes_t cnt)
 {
 	if (sf_seek (sf, frame_pos, SEEK_SET|SFM_WRITE) < 0) {
 		char errbuf[256];
@@ -572,7 +572,7 @@ SndFileSource::write_float (Sample* data, nframes_t frame_pos, nframes_t cnt)
 	return cnt;
 }
 
-nframes_t
+sframes_t
 SndFileSource::natural_position() const
 {
 	return _timeline_position;
@@ -605,7 +605,7 @@ SndFileSource::clear_capture_marks ()
 }	
 
 void
-SndFileSource::mark_capture_start (nframes_t pos)
+SndFileSource::mark_capture_start (sframes_t pos)
 {
 	if (destructive()) {
 		if (pos < _timeline_position) {
@@ -748,7 +748,7 @@ SndFileSource::crossfade (Sample* data, nframes_t cnt, int fade_in)
 	return cnt;
 }
 
-nframes_t
+sframes_t
 SndFileSource::last_capture_start_frame () const
 {
 	if (destructive()) {
diff --git a/libs/ardour/source.cc b/libs/ardour/source.cc
index 12a5e7c071..5c2ac132e1 100644
--- a/libs/ardour/source.cc
+++ b/libs/ardour/source.cc
@@ -140,7 +140,7 @@ Source::set_state (const XMLNode& node)
 }
 
 void
-Source::update_length (nframes_t pos, nframes_t cnt)
+Source::update_length (sframes_t pos, sframes_t cnt)
 {
 	if (pos + cnt > _length) {
 		_length = pos + cnt;