(FULL commit) start of a nominal debug tracing system, with 64 bits available for flags; track notes by region in MidiPlaylist, and resolve them if they are left hanging at region boundaries. note: MIDI playback is still not working 100% though its better now.

git-svn-id: svn://localhost/ardour2/branches/3.0@5903 d708f5d6-7413-0410-9779-e7cbd77b26cf

12 files changed, 323 insertions, 44 deletions

diff --git a/libs/ardour/ardour/debug.h b/libs/ardour/ardour/debug.h
new file mode 100644
index 0000000000..db482275a9
--- /dev/null
+++ b/libs/ardour/ardour/debug.h
@@ -0,0 +1,52 @@
+/*
+    Copyright (C) 2009 Paul Davis
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef __ardour_debug_h__
+#define __ardour_debug_h__
+
+#include <sstream>
+
+namespace ARDOUR {
+
+	extern uint64_t debug_bits;
+	void debug_print (std::string str);
+	void set_debug_bits (uint64_t bits);
+
+	namespace DEBUG {
+
+		/* this namespace is so that we can write DEBUG::bit_name */
+		   
+		enum DebugBits {
+			MidiSourceIO = 0x1
+		};
+       }
+}
+
+#ifndef NDEBUG
+#define DEBUG_TRACE(bits,str) if ((bits) & ARDOUR::debug_bits) { ARDOUR::debug_print (str); }
+#define DEBUG_STR_SET(id,s) std::stringstream __debug_str ## id; __debug_str ## id << s;
+#define DEBUG_STR(id) __debug_str ## id
+#else
+#define DEBUG_TRACE(bits,fmt,...) /*empty*/
+#define DEBUG_STR_SET(a,b) /* empty */
+#define DEBUG_STR(a) /* empty */
+#endif
+
+#endif /* __ardour_debug_h__ */
+
diff --git a/libs/ardour/ardour/midi_region.h b/libs/ardour/ardour/midi_region.h
index f8f663bc78..5bd338b39e 100644
--- a/libs/ardour/ardour/midi_region.h
+++ b/libs/ardour/ardour/midi_region.h
@@ -56,7 +56,7 @@ class MidiRegion : public Region
 	virtual nframes_t read (Sample*, sframes_t /*pos*/, nframes_t /*cnt*/, int /*channel*/) const { return 0; }
 	virtual sframes_t readable_length() const { return length(); }
 
-	nframes_t read_at (MidiRingBuffer<nframes_t>& dst,
+	nframes_t read_at (Evoral::EventSink<nframes_t>& dst,
 			   sframes_t position,
 			   nframes_t dur,
 			   uint32_t  chan_n = 0,
@@ -105,7 +105,7 @@ class MidiRegion : public Region
 	MidiRegion (const SourceList &, const XMLNode&);
 
   private:
-	nframes_t _read_at (const SourceList&, MidiRingBuffer<nframes_t>& dst,
+	nframes_t _read_at (const SourceList&, Evoral::EventSink<nframes_t>& dst,
 			    sframes_t position,
 			    nframes_t dur,
 			    uint32_t chan_n = 0,
diff --git a/libs/ardour/ardour/midi_source.h b/libs/ardour/ardour/midi_source.h
index 1b452a7c4d..b11387f8de 100644
--- a/libs/ardour/ardour/midi_source.h
+++ b/libs/ardour/ardour/midi_source.h
@@ -58,14 +58,14 @@ class MidiSource : virtual public Source
 	 * \param negative_stamp_offset Offset to subtract from event times written to dst
 	 * \param tracker an optional pointer to MidiStateTracker object, for note on/off tracking
 	 */
-	virtual nframes_t midi_read (MidiRingBuffer<nframes_t>& dst,
+	virtual nframes_t midi_read (Evoral::EventSink<nframes_t>& dst,
 				     sframes_t source_start,
 				     sframes_t start, nframes_t cnt,
 				     sframes_t stamp_offset, sframes_t negative_stamp_offset, MidiStateTracker*) const;
 
 	virtual nframes_t midi_write (MidiRingBuffer<nframes_t>& src,
-			sframes_t source_start,
-			nframes_t cnt);
+				      sframes_t source_start,
+				      nframes_t cnt);
 
 	virtual void append_event_unlocked_beats(const Evoral::Event<Evoral::MusicalTime>& ev) = 0;
 
@@ -114,7 +114,7 @@ class MidiSource : virtual public Source
   protected:
 	virtual void flush_midi() = 0;
 
-	virtual nframes_t read_unlocked (MidiRingBuffer<nframes_t>& dst,
+	virtual nframes_t read_unlocked (Evoral::EventSink<nframes_t>& dst,
 					 sframes_t position,
 					 sframes_t start, nframes_t cnt,
 					 sframes_t stamp_offset, sframes_t negative_stamp_offset,
diff --git a/libs/ardour/ardour/midi_state_tracker.h b/libs/ardour/ardour/midi_state_tracker.h
index 7b95772cac..76a669838a 100644
--- a/libs/ardour/ardour/midi_state_tracker.h
+++ b/libs/ardour/ardour/midi_state_tracker.h
@@ -23,9 +23,12 @@
 #include <bitset>
 #include "ardour/midi_buffer.h"
 
+namespace Evoral {
+template <typename T> class EventSink;
+}
+
 namespace ARDOUR {
 
-template <typename T> class MidiRingBuffer;
 
 /** Tracks played notes, so they can be resolved in potential stuck note
  * situations (e.g. looping, transport stop, etc).
@@ -39,14 +42,17 @@ public:
 	void add (uint8_t note, uint8_t chn);
 	void remove (uint8_t note, uint8_t chn);
 	void resolve_notes (MidiBuffer& buffer, nframes64_t time);
-	void resolve_notes (MidiRingBuffer<nframes_t>& buffer, nframes64_t time);
+	void resolve_notes (Evoral::EventSink<nframes_t>& buffer, nframes64_t time);
 	void dump (std::ostream&);
 	void reset ();
+	bool empty() const { return _on == 0; }
+	uint16_t on() const { return _on; }
 
 private:
 	void track_note_onoffs(const Evoral::MIDIEvent<MidiBuffer::TimeType>& event);
 
-	uint8_t _active_notes[128*16];
+	uint8_t  _active_notes[128*16];
+	uint16_t _on;
 };
 
 
diff --git a/libs/ardour/ardour/smf_source.h b/libs/ardour/ardour/smf_source.h
index e02f8eddc0..5ded3537e9 100644
--- a/libs/ardour/ardour/smf_source.h
+++ b/libs/ardour/ardour/smf_source.h
@@ -70,7 +70,7 @@ public:
 	static bool safe_midi_file_extension (const Glib::ustring& path);
 
 private:
-	nframes_t read_unlocked (MidiRingBuffer<nframes_t>& dst,
+	nframes_t read_unlocked (Evoral::EventSink<nframes_t>& dst,
 				 sframes_t position,
 				 sframes_t start,
 				 nframes_t cnt,
diff --git a/libs/ardour/globals.cc b/libs/ardour/globals.cc
index e7fd81349f..6cd6d0ea16 100644
--- a/libs/ardour/globals.cc
+++ b/libs/ardour/globals.cc
@@ -59,6 +59,7 @@
 #include "midi++/mmc.h"
 
 #include "ardour/ardour.h"
+#include "ardour/debug.h"
 #include "ardour/analyser.h"
 #include "ardour/audio_library.h"
 #include "ardour/rc_configuration.h"
@@ -89,6 +90,8 @@ using namespace ARDOUR;
 using namespace std;
 using namespace PBD;
 
+uint64_t ARDOUR::debug_bits = 0x0;
+
 MIDI::Port *ARDOUR::default_mmc_port = 0;
 MIDI::Port *ARDOUR::default_mtc_port = 0;
 MIDI::Port *ARDOUR::default_midi_port = 0;
@@ -108,6 +111,18 @@ mix_buffers_no_gain_t   ARDOUR::mix_buffers_no_gain = 0;
 
 sigc::signal<void,std::string> ARDOUR::BootMessage;
 
+void
+ARDOUR::debug_print (std::string str)
+{
+	cerr << str;
+}
+
+void
+ARDOUR::set_debug_bits (uint64_t bits)
+{
+	debug_bits = bits;
+}
+
 int
 ARDOUR::setup_midi ()
 {
diff --git a/libs/ardour/midi_playlist.cc b/libs/ardour/midi_playlist.cc
index 49b5ff2c4f..df8e3e7000 100644
--- a/libs/ardour/midi_playlist.cc
+++ b/libs/ardour/midi_playlist.cc
@@ -20,11 +20,13 @@
 #include <cassert>
 
 #include <algorithm>
+#include <iostream>
 
 #include <stdlib.h>
-
 #include <sigc++/bind.h>
 
+#include "evoral/EventList.hpp"
+
 #include "ardour/types.h"
 #include "ardour/configuration.h"
 #include "ardour/midi_playlist.h"
@@ -122,6 +124,13 @@ struct RegionSortByLayer {
     }
 };
 
+template<typename Time>
+struct EventsSortByTime {
+    bool operator() (Evoral::Event<Time>* a, Evoral::Event<Time>* b) {
+	    return a->time() < b->time();
+    }
+};
+
 /** Returns the number of frames in time duration read (eg could be large when 0 events are read) */
 nframes_t
 MidiPlaylist::read (MidiRingBuffer<nframes_t>& dst, nframes_t start, nframes_t dur, unsigned chan_n)
@@ -131,6 +140,7 @@ MidiPlaylist::read (MidiRingBuffer<nframes_t>& dst, nframes_t start, nframes_t d
 	*/
 
 	Glib::RecMutex::Lock rm (region_lock);
+	cerr << "++++++" << start << " .. " << start + dur << " channel " << chan_n << " +++++++++++++++++++++++++++++++++++++++++++++++\n";
 
 	nframes_t end = start + dur - 1;
 
@@ -138,47 +148,167 @@ MidiPlaylist::read (MidiRingBuffer<nframes_t>& dst, nframes_t start, nframes_t d
 
 	// relevent regions overlapping start <--> end
 	vector< boost::shared_ptr<Region> > regs;
+	typedef pair<MidiStateTracker*,nframes64_t> TrackerInfo;
+	vector<TrackerInfo> tracker_info;
+	uint32_t note_cnt = 0;
 
 	for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
 		if ((*i)->coverage (start, end) != OverlapNone) {
 			regs.push_back(*i);
 		} else {
-			/* region does not cover the current read boundaries, so make
-			   sure that we silence any notes that it had turned on
-			*/
 			NoteTrackers::iterator t = _note_trackers.find ((*i).get());
 			if (t != _note_trackers.end()) {
-				t->second->resolve_notes (dst, (*i)->last_frame());
-				delete t->second;
+
+				/* add it the set of trackers we will do note resolution
+				   on, and remove it from the list we are keeping 
+				   around, because we don't need it anymore.
+				*/
+				
+				tracker_info.push_back (TrackerInfo (t->second, (*i)->last_frame()));
+				cerr << "time to resolve & remove tracker for " << (*i)->name() << endl;
+				note_cnt += (t->second->on());
 				_note_trackers.erase (t);
 			}
 		}
 	}
 
-	RegionSortByLayer layer_cmp;
-	sort(regs.begin(), regs.end(), layer_cmp);
+	if (note_cnt == 0 && !tracker_info.empty()) {
+		/* trackers to dispose of, but they have no notes in them */
+		cerr << "Clearing " << tracker_info.size() << " empty trackers\n";
+		for (vector<TrackerInfo>::iterator t = tracker_info.begin(); t != tracker_info.end(); ++t) {
+			delete (*t).first;
+		}
+		tracker_info.clear ();
+	}
+			
+	if (regs.size() == 1 && tracker_info.empty()) {
+	
+		/* just a single region - read directly into dst */
+
+		cerr << "Single region (" << regs.front()->name() << ") read, no out-of-bound region tracking info\n";
+
+		boost::shared_ptr<MidiRegion> mr = boost::dynamic_pointer_cast<MidiRegion>(regs.front());
 
-	for (vector<boost::shared_ptr<Region> >::iterator i = regs.begin(); i != regs.end(); ++i) {
-		boost::shared_ptr<MidiRegion> mr = boost::dynamic_pointer_cast<MidiRegion>(*i);
 		if (mr) {
 
-			NoteTrackers::iterator t = _note_trackers.find ((*i).get());
+			NoteTrackers::iterator t = _note_trackers.find (mr.get());
 			MidiStateTracker* tracker;
+			bool new_tracker = false;
 
 			if (t == _note_trackers.end()) {
+				tracker = new MidiStateTracker;
+				new_tracker = true;
+				cerr << "\tBEFORE: new tracker\n";
+			} else {
+				tracker = t->second;
+				cerr << "\tBEFORE: tracker says there are " << tracker->on() << " on notes\n";
+			}
+			
+			mr->read_at (dst, start, dur, chan_n, _note_mode, tracker);
+			cerr << "\tAFTER: tracker says there are " << tracker->on() << " on notes\n";
+			
+			if (new_tracker) {
 				pair<Region*,MidiStateTracker*> newpair;
-				newpair.first = (*i).get();
-				tracker = newpair.second = new MidiStateTracker;
+				newpair.first = mr.get();
+				newpair.second = tracker;
 				_note_trackers.insert (newpair);
+				cerr << "\tadded tracker to trackers\n";
+			}
+
+			_read_data_count += mr->read_data_count();
+		}
+		
+	} else {
+
+		/* multiple regions and/or note resolution: sort by layer, read into a temporary non-monotonically 
+		   sorted EventSink, sort and then insert into dst.
+		*/
+
+		cerr << regs.size() << " regions to read, plus " << tracker_info.size() << " trackers\n";
+		
+		Evoral::EventList<nframes_t> evlist;
+
+		for (vector<TrackerInfo>::iterator t = tracker_info.begin(); t != tracker_info.end(); ++t) {
+			cerr << "Resolve " << (*t).first->on() << " notes\n";
+			(*t).first->resolve_notes (evlist, (*t).second);
+			delete (*t).first;
+		}
+		
+		cerr << "After resolution we now have " << evlist.size() << " events\n";
+		for (Evoral::EventList<nframes_t>::iterator x = evlist.begin(); x != evlist.end(); ++x) {
+			cerr << '\t' << **x << endl;
+		}			
+
+		RegionSortByLayer layer_cmp;
+		sort(regs.begin(), regs.end(), layer_cmp);
+
+		cerr << "for " << start << " .. " << start+dur-1 << " We have " << regs.size() << " regions to consider\n";
+		
+		for (vector<boost::shared_ptr<Region> >::iterator i = regs.begin(); i != regs.end(); ++i) {
+			boost::shared_ptr<MidiRegion> mr = boost::dynamic_pointer_cast<MidiRegion>(*i);
+			if (!mr) {
+				continue;
+			}
+
+			NoteTrackers::iterator t = _note_trackers.find (mr.get());
+			MidiStateTracker* tracker;
+			bool new_tracker = false;
+
+			cerr << "Before " << mr->name() << " (" << mr->position() << " .. " << mr->last_frame() << ") we now have " << evlist.size() << " events\n";
+
+			if (t == _note_trackers.end()) {
+				tracker = new MidiStateTracker;
+				new_tracker = true;
+				cerr << "\tBEFORE: tracker says there are " << tracker->on() << " on notes\n";
 			} else {
 				tracker = t->second;
+				cerr << "\tBEFORE: tracker says there are " << tracker->on() << " on notes\n";
 			}
 
-			mr->read_at (dst, start, dur, chan_n, _note_mode, tracker);
+			mr->read_at (evlist, start, dur, chan_n, _note_mode, tracker);
 			_read_data_count += mr->read_data_count();
+
+			cerr << "After " << mr->name() << " (" << mr->position() << " .. " << mr->last_frame() << ") we now have " << evlist.size() << " events\n";
+			for (Evoral::EventList<nframes_t>::iterator x = evlist.begin(); x != evlist.end(); ++x) {
+				cerr << '\t' << **x << endl;
+			}			
+			cerr << "\tAFTER: tracker says there are " << tracker->on() << " on notes\n";
+
+			if (new_tracker) {
+				pair<Region*,MidiStateTracker*> newpair;
+				newpair.first = mr.get();
+				newpair.second = tracker;
+				_note_trackers.insert (newpair);
+				cerr << "\tadded tracker to trackers\n";
+			} 
+		}
+
+		cerr << "Final we now have " << evlist.size() << " events\n";
+		for (Evoral::EventList<nframes_t>::iterator x = evlist.begin(); x != evlist.end(); ++x) {
+			cerr << '\t' << **x << endl;
+		}			
+		
+		if (!evlist.empty()) {
+		
+			/* sort the event list */
+			EventsSortByTime<nframes_t> time_cmp;
+			evlist.sort (time_cmp);
+			
+			cerr << "Post sort: we now have " << evlist.size() << " events\n";
+			for (Evoral::EventList<nframes_t>::iterator x = evlist.begin(); x != evlist.end(); ++x) {
+				cerr << '\t' << **x << endl;
+			}			
+			
+			/* write into dst */
+			for (Evoral::EventList<nframes_t>::iterator e = evlist.begin(); e != evlist.end(); ++e) {
+				Evoral::Event<nframes_t>* ev (*e);
+				dst.write (ev->time(), ev->event_type(), ev->size(), ev->buffer());
+				delete ev;
+			}
 		}
 	}
 
+	cerr << "-------------------------------------------------------------\n";
 	return dur;
 }
 
diff --git a/libs/ardour/midi_region.cc b/libs/ardour/midi_region.cc
index 56a52bf4e7..b95f35f726 100644
--- a/libs/ardour/midi_region.cc
+++ b/libs/ardour/midi_region.cc
@@ -130,7 +130,7 @@ MidiRegion::set_position_internal (nframes_t pos, bool allow_bbt_recompute)
 }
 
 nframes_t
-MidiRegion::read_at (MidiRingBuffer<nframes_t>& out, sframes_t position, nframes_t dur, uint32_t chan_n, NoteMode mode, MidiStateTracker* tracker) const
+MidiRegion::read_at (Evoral::EventSink<nframes_t>& out, sframes_t position, nframes_t dur, uint32_t chan_n, NoteMode mode, MidiStateTracker* tracker) const
 {
 	return _read_at (_sources, out, position, dur, chan_n, mode, tracker);
 }
@@ -142,9 +142,8 @@ MidiRegion::master_read_at (MidiRingBuffer<nframes_t>& out, sframes_t position,
 }
 
 nframes_t
-MidiRegion::_read_at (const SourceList& /*srcs*/,
-		MidiRingBuffer<nframes_t>& dst, sframes_t position, nframes_t dur, uint32_t chan_n,
-		NoteMode mode, MidiStateTracker* tracker) const
+MidiRegion::_read_at (const SourceList& /*srcs*/, Evoral::EventSink<nframes_t>& dst, sframes_t position, nframes_t dur, uint32_t chan_n, 
+		      NoteMode mode, MidiStateTracker* tracker) const
 {
 	nframes_t internal_offset = 0;
 	nframes_t src_offset      = 0;
diff --git a/libs/ardour/midi_source.cc b/libs/ardour/midi_source.cc
index 9f7c1e3baa..81282c5313 100644
--- a/libs/ardour/midi_source.cc
+++ b/libs/ardour/midi_source.cc
@@ -33,6 +33,7 @@
 #include "pbd/basename.h"
 
 #include "ardour/audioengine.h"
+#include "ardour/debug.h"
 #include "ardour/midi_model.h"
 #include "ardour/midi_ring_buffer.h"
 #include "ardour/midi_state_tracker.h"
@@ -129,7 +130,7 @@ MidiSource::invalidate ()
 }
 
 nframes_t
-MidiSource::midi_read (MidiRingBuffer<nframes_t>& dst, sframes_t source_start,
+MidiSource::midi_read (Evoral::EventSink<nframes_t>& dst, sframes_t source_start,
 		       sframes_t start, nframes_t cnt,
 		       sframes_t stamp_offset, sframes_t negative_stamp_offset,
 		       MidiStateTracker* tracker) const
@@ -139,18 +140,19 @@ MidiSource::midi_read (MidiRingBuffer<nframes_t>& dst, sframes_t source_start,
 	BeatsFramesConverter converter(_session, source_start);
 
 	if (_model) {
-#define BEATS_TO_FRAMES(t) (converter.to(t) + stamp_offset - negative_stamp_offset)
-
 		Evoral::Sequence<double>::const_iterator& i = _model_iter;
 
 		// If the cached iterator is invalid, search for the first event past start
 		if (_last_read_end == 0 || start != _last_read_end || !_model_iter_valid) {
+			DEBUG_TRACE (DEBUG::MidiSourceIO, string_compose ("****!!!!**** search for relevant iterator for %1 / %2\n", source_start, start));
 			for (i = _model->begin(); i != _model->end(); ++i) {
 				if (converter.to(i->time()) >= start) {
 					break;
 				}
 			}
 			_model_iter_valid = true;
+		} else {
+			DEBUG_TRACE (DEBUG::MidiSourceIO, string_compose ("============ use cached iterator for %1 / %2\n", source_start, start));
 		}
 
 		_last_read_end = start + cnt;
@@ -164,8 +166,10 @@ MidiSource::midi_read (MidiRingBuffer<nframes_t>& dst, sframes_t source_start,
 				if (tracker) {
 					Evoral::MIDIEvent<Evoral::MusicalTime>& ev (*(Evoral::MIDIEvent<Evoral::MusicalTime>*) (&(*i)));
 					if (ev.is_note_on()) {
+						DEBUG_TRACE (DEBUG::MidiSourceIO, string_compose ("\t%1 Added note on %2 @ %3\n", _name, ev.note(), time_frames));
 						tracker->add (ev.note(), ev.channel());
 					} else if (ev.is_note_off()) {
+						DEBUG_TRACE (DEBUG::MidiSourceIO, string_compose ("\t%1 Added note OFF %2 @ %3\n", _name, ev.note(), time_frames));
 						tracker->remove (ev.note(), ev.channel());
 					}
 				}
diff --git a/libs/ardour/midi_state_tracker.cc b/libs/ardour/midi_state_tracker.cc
index 0ddafc3fed..03ac16ca87 100644
--- a/libs/ardour/midi_state_tracker.cc
+++ b/libs/ardour/midi_state_tracker.cc
@@ -35,17 +35,16 @@ void
 MidiStateTracker::reset ()
 {
 	memset (_active_notes, 0, sizeof (_active_notes));
+	_on = 0;
 }
 
 void
 MidiStateTracker::track_note_onoffs (const Evoral::MIDIEvent<MidiBuffer::TimeType>& event)
 {
 	if (event.is_note_on()) {
-		_active_notes [event.note() + 128 * event.channel()]++;
+		add (event.note(), event.channel());
 	} else if (event.is_note_off()){
-		if (_active_notes[event.note() + 128 * event.channel()]) {
-			_active_notes [event.note() + 128 * event.channel()]--;
-		}
+		remove (event.note(), event.channel());
 	}
 }
 
@@ -53,13 +52,23 @@ void
 MidiStateTracker::add (uint8_t note, uint8_t chn)
 {
 	++_active_notes[note + 128 * chn];
+	++_on;
 }
 
 void
 MidiStateTracker::remove (uint8_t note, uint8_t chn)
 {
-	if (_active_notes[note + 128 * chn]) {
-		--_active_notes[note + 128 * chn];
+	switch (_active_notes[note + 128 * chn]) {
+	case 0:
+		break;
+	case 1:
+		--_on;
+		_active_notes [note + 128 * chn] = 0;
+		break;
+	default:
+		--_active_notes [note + 128 * chn];
+				break;
+
 	}
 }
 
@@ -82,35 +91,45 @@ MidiStateTracker::track (const MidiBuffer::iterator &from, const MidiBuffer::ite
 void
 MidiStateTracker::resolve_notes (MidiBuffer &dst, nframes64_t time)
 {
+	if (!_on) {
+		return;
+	}
+
 	for (int channel = 0; channel < 16; ++channel) {
 		for (int note = 0; note < 128; ++note) {
-			while (_active_notes[channel * 128 + note]) {
+			while (_active_notes[note + 128 * channel]) {
 				uint8_t buffer[3] = { MIDI_CMD_NOTE_OFF | channel, note, 0 };
 				Evoral::MIDIEvent<MidiBuffer::TimeType> noteoff
 					(time, MIDI_CMD_NOTE_OFF, 3, buffer, false);
 				dst.push_back (noteoff);
-
-				_active_notes[channel * 128 + note]--;
+				_active_notes[note + 128 * channel]--;
 			}
 		}
 	}
+	_on = 0;
 }
 
 void
-MidiStateTracker::resolve_notes (MidiRingBuffer<nframes_t> &dst, nframes64_t time)
+MidiStateTracker::resolve_notes (Evoral::EventSink<nframes_t> &dst, nframes64_t time)
 {
 	uint8_t buf[3];
+
+	if (!_on) {
+		return;
+	}
+
 	for (int channel = 0; channel < 16; ++channel) {
 		for (int note = 0; note < 128; ++note) {
-			while (_active_notes[channel * 128 + note]) {
+			while (_active_notes[note + 128 * channel]) {
 				buf[0] = MIDI_CMD_NOTE_OFF|channel;
 				buf[1] = note;
 				buf[2] = 0;
 				dst.write (time, EventTypeMap::instance().midi_event_type (buf[0]), 3, buf);
-				_active_notes[channel * 128 + note]--;
+				_active_notes[note + 128 * channel]--;
 			}
 		}
 	}
+	_on = 0;
 }
 
 void
diff --git a/libs/ardour/smf_source.cc b/libs/ardour/smf_source.cc
index c940bd3331..d756e86109 100644
--- a/libs/ardour/smf_source.cc
+++ b/libs/ardour/smf_source.cc
@@ -102,7 +102,7 @@ SMFSource::~SMFSource ()
 
 /** All stamps in audio frames */
 nframes_t
-SMFSource::read_unlocked (MidiRingBuffer<nframes_t>& destination, sframes_t source_start,
+SMFSource::read_unlocked (Evoral::EventSink<nframes_t>& destination, sframes_t source_start,
 			  sframes_t start, nframes_t duration,
 			  sframes_t stamp_offset, sframes_t negative_stamp_offset,
 			  MidiStateTracker* tracker) const
diff --git a/libs/evoral/evoral/EventList.hpp b/libs/evoral/evoral/EventList.hpp
new file mode 100644
index 0000000000..390d90dd5b
--- /dev/null
+++ b/libs/evoral/evoral/EventList.hpp
@@ -0,0 +1,54 @@
+/* This file is part of Evoral.
+ * Copyright (C) 2008 Dave Robillard <http://drobilla.net>
+ *
+ * Evoral is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * Evoral is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef EVORAL_EVENT_LIST_HPP
+#define EVORAL_EVENT_LIST_HPP
+
+#include <list>
+#include "evoral/EventSink.hpp"
+#include "evoral/types.hpp"
+#include "evoral/Event.hpp"
+
+namespace Evoral {
+
+
+/** A list of events (generic time-stamped binary "blobs").
+ *
+ * Used when we need an unsorted list of Events that is also an EventSink. Absolutely nothing more.
+ */
+template<typename Time>
+class EventList : public std::list<Evoral::Event<Time> *>, public Evoral::EventSink<Time> {
+public:
+        EventList() {}
+    
+        uint32_t write(Time  time, EventType  type, uint32_t  size, const uint8_t* buf);
+};
+
+template<typename Time>
+inline uint32_t
+EventList<Time>::write(Time time, EventType type, uint32_t size, const uint8_t* buf)
+{
+	Evoral::Event<Time>* e = new Evoral::Event<Time> (type, time, size, const_cast<uint8_t*> (buf), true); // event makes copy of buffer
+	push_back (e);
+	return size;
+}
+
+
+} // namespace Evoral
+
+#endif // EVORAL_EVENT_LIST_HPP
+