do not allow smf_source's reads to stomp on cached read_end position in parent class...
[ardour.git] / libs / ardour / smf_source.cc
index cdf252c8cf8732510dccd143ed821861d7b176e9..7fbc8b0287d29296fc5106c292dc8dc03c92e567 100644 (file)
 #include <unistd.h>
 #include <errno.h>
 
-#include <pbd/mountpoint.h>
-#include <pbd/pathscanner.h>
-#include <pbd/stl_delete.h>
-#include <pbd/strsplit.h>
+#include "pbd/mountpoint.h"
+#include "pbd/pathscanner.h"
+#include "pbd/stl_delete.h"
+#include "pbd/strsplit.h"
 
 #include <glibmm/miscutils.h>
 
-#include <evoral/SMFReader.hpp>
-#include <evoral/Control.hpp>
+#include "evoral/SMFReader.hpp"
+#include "evoral/Control.hpp"
 
-#include <ardour/smf_source.h>
-#include <ardour/session.h>
-#include <ardour/midi_ring_buffer.h>
-#include <ardour/tempo.h>
-#include <ardour/audioengine.h>
-#include <ardour/event_type_map.h>
+#include "ardour/audioengine.h"
+#include "ardour/event_type_map.h"
+#include "ardour/midi_model.h"
+#include "ardour/midi_ring_buffer.h"
+#include "ardour/session.h"
+#include "ardour/smf_source.h"
 
 #include "i18n.h"
 
 using namespace ARDOUR;
-
-string SMFSource::_search_path;
-
-/*sigc::signal<void,struct tm*, time_t> SMFSource::HeaderPositionOffsetChanged;
-bool                                  SMFSource::header_position_negative;
-uint64_t                              SMFSource::header_position_offset;
-*/
-
-SMFSource::SMFSource (Session& s, std::string path, Flag flags)
-       : MidiSource (s, region_name_from_path(path, false))
-       , Evoral::SMF<double> ()
-       , _flags (Flag(flags | Writable)) // FIXME: this needs to be writable for now
-       , _allow_remove_if_empty(true)
-       , _last_ev_time(0)
+using namespace Glib;
+
+/** Constructor used for new internal-to-session files.  File cannot exist. */
+SMFSource::SMFSource (Session& s, const ustring& path, bool embedded, Source::Flag flags)
+       : Source(s, DataType::MIDI, path, flags)
+       , MidiSource(s, path)
+       , FileSource(s, DataType::MIDI, path, embedded, flags)
+       , Evoral::SMF()
+       , _last_ev_time_beats(0.0)
+       , _last_ev_time_frames(0)
+       , _smf_last_read_end (0)
 {
-       /* constructor used for new internal-to-session files. file cannot exist */
-
-       if (init (path, false)) {
+       if (init(_name, false)) {
                throw failed_constructor ();
        }
        
        if (create(path)) {
                throw failed_constructor ();
        }
-
-       assert(_name.find("/") == string::npos);
 }
 
-SMFSource::SMFSource (Session& s, const XMLNode& node)
-       : MidiSource (s, node)
-       , _flags (Flag (Writable|CanRename))
-       , _allow_remove_if_empty(true)
-       , _last_ev_time(0)
+/** Constructor used for existing internal-to-session files. */
+SMFSource::SMFSource (Session& s, const XMLNode& node, bool must_exist)
+       : Source(s, node)
+       , MidiSource(s, node)
+       , FileSource(s, node, must_exist)
+       , _last_ev_time_beats(0.0)
+       , _last_ev_time_frames(0)
+       , _smf_last_read_end (0)
 {
-       /* constructor used for existing internal-to-session files. file must exist */
-
-       if (set_state (node)) {
+       if (set_state(node)) {
                throw failed_constructor ();
        }
        
-       if (init (_name, true)) {
+       if (init(_name, true)) {
                throw failed_constructor ();
        }
        
        if (open(_path)) {
                throw failed_constructor ();
        }
-       
-       assert(_name.find("/") == string::npos);
 }
 
 SMFSource::~SMFSource ()
@@ -103,264 +95,249 @@ SMFSource::~SMFSource ()
        }
 }
 
-bool
-SMFSource::removable () const
-{
-       return (_flags & Removable) && ((_flags & RemoveAtDestroy) || 
-                                     ((_flags & RemovableIfEmpty) && is_empty()));
-}
-
-int
-SMFSource::init (string pathstr, bool must_exist)
-{
-       bool is_new = false;
-
-       if (!find (pathstr, must_exist, is_new)) {
-               cerr << "cannot find " << pathstr << " with me = " << must_exist << endl;
-               return -1;
-       }
-
-       if (is_new && must_exist) {
-               return -1;
-       }
-
-       assert(_name.find("/") == string::npos);
-       return 0;
-}
-
 /** All stamps in audio frames */
 nframes_t
-SMFSource::read_unlocked (MidiRingBuffer<double>& dst, nframes_t start, nframes_t cnt, nframes_t stamp_offset, nframes_t negative_stamp_offset) const
+SMFSource::read_unlocked (MidiRingBuffer<nframes_t>& destination, sframes_t source_start,
+               sframes_t start, nframes_t duration,
+               sframes_t stamp_offset, sframes_t negative_stamp_offset) const
 {
-       //cerr << "SMF read_unlocked " << name() << " read " << start << ", count=" << cnt << ", offset=" << stamp_offset << endl;
-
-       // 64 bits ought to be enough for anybody
+       int      ret  = 0;
        uint64_t time = 0; // in SMF ticks, 1 tick per _ppqn
 
        _read_data_count = 0;
 
        // Output parameters for read_event (which will allocate scratch in buffer as needed)
        uint32_t ev_delta_t = 0;
-       uint32_t ev_type = 0;
-       uint32_t ev_size = 0;
-       uint8_t* ev_buffer = 0;
+       uint32_t ev_type    = 0;
+       uint32_t ev_size    = 0;
+       uint8_t* ev_buffer  = 0;
 
        size_t scratch_size = 0; // keep track of scratch to minimize reallocs
-
-       // FIXME: don't seek to start and search every read (brutal!)
-       Evoral::SMF<double>::seek_to_start();
        
-       // FIXME: assumes tempo never changes after start
-       const double frames_per_beat = _session.tempo_map().tempo_at(_timeline_position).frames_per_beat(
-                       _session.engine().frame_rate(),
-                       _session.tempo_map().meter_at(_timeline_position));
+       BeatsFramesConverter converter(_session, source_start);
+
+       const uint64_t start_ticks = (uint64_t)(converter.from(start) * ppqn());
+
+       if (_smf_last_read_end == 0 || start != _smf_last_read_end) {
+               //cerr << "SMFSource::read_unlocked seeking to " << start << endl;
+               Evoral::SMF::seek_to_start();
+               while (time < start_ticks) {
+                       ret = read_event(&ev_delta_t, &ev_size, &ev_buffer);
+                       if (ret == -1) { // EOF
+                               _smf_last_read_end = start + duration;
+                               return duration;
+                       }
+                       time += ev_delta_t; // accumulate delta time
+               }
+       }
        
-       const uint64_t start_ticks = (uint64_t)((start / frames_per_beat) * ppqn());
+       _smf_last_read_end = start + duration;
 
-       while (!Evoral::SMF<double>::eof()) {
-               int ret = read_event(&ev_delta_t, &ev_size, &ev_buffer);
+       while (true) {
+               ret = read_event(&ev_delta_t, &ev_size, &ev_buffer);
                if (ret == -1) { // EOF
-                       //cerr << "SMF - EOF\n";
                        break;
                }
                
-               ev_type = EventTypeMap::instance().midi_event_type(ev_buffer[0]);
-               
                time += ev_delta_t; // accumulate delta time
 
                if (ret == 0) { // meta-event (skipped, just accumulate time)
-                       //cerr << "SMF - META\n";
                        continue;
                }
+               
+               ev_type = EventTypeMap::instance().midi_event_type(ev_buffer[0]);
 
-               if (time >= start_ticks) {
-                       const nframes_t ev_frame_time = (nframes_t)(
-                                       ((time / (double)ppqn()) * frames_per_beat)) + stamp_offset;
+               assert(time >= start_ticks);
+               const sframes_t ev_frame_time = converter.to(time / (double)ppqn()) + stamp_offset;
 
-                       if (ev_frame_time <= start + cnt)
-                               dst.write(ev_frame_time - negative_stamp_offset, ev_type, ev_size, ev_buffer);
-                       else
-                               break;
+               if (ev_frame_time < start + duration) {
+                       destination.write(ev_frame_time - negative_stamp_offset, ev_type, ev_size, ev_buffer);
+               } else {
+                       break;
                }
 
                _read_data_count += ev_size;
 
-               if (ev_size > scratch_size)
+               if (ev_size > scratch_size) {
                        scratch_size = ev_size;
-               else
-                       ev_size = scratch_size; // minimize realloc in read_event
+               }
+               ev_size = scratch_size; // ensure read_event only allocates if necessary
        }
        
-       return cnt;
+       return duration;
 }
 
 /** All stamps in audio frames */
 nframes_t
-SMFSource::write_unlocked (MidiRingBuffer<double>& src, nframes_t cnt)
+SMFSource::write_unlocked (MidiRingBuffer<nframes_t>& source, sframes_t position, nframes_t duration)
 {
        _write_data_count = 0;
                
-       double            time;
+       nframes_t         time;
        Evoral::EventType type;
        uint32_t          size;
 
-       size_t buf_capacity = 4;
-       uint8_t* buf = (uint8_t*)malloc(buf_capacity);
+       size_t   buf_capacity = 4;
+       uint8_t* buf          = (uint8_t*)malloc(buf_capacity);
        
-       if (_model && ! _model->writing())
+       if (_model && ! _model->writing()) {
                _model->start_write();
+       }
 
-       Evoral::MIDIEvent<double> ev(0, 0.0, 4, NULL, true);
+       Evoral::MIDIEvent<nframes_t> ev;
 
        while (true) {
-               bool ret = src.peek_time(&time);
-               if (!ret || time - _timeline_position > _length + cnt)
+               bool ret = source.peek_time(&time);
+               if (!ret || time > _last_write_end + duration) {
                        break;
+               }
 
-               ret = src.read_prefix(&time, &type, &size);
-               if (!ret)
+               ret = source.read_prefix(&time, &type, &size);
+               if (!ret) {
+                       cerr << "ERROR: Unable to read event prefix, corrupt MIDI ring buffer" << endl;
                        break;
+               }
 
                if (size > buf_capacity) {
                        buf_capacity = size;
                        buf = (uint8_t*)realloc(buf, size);
                }
 
-               ret = src.read_contents(size, buf);
+               ret = source.read_contents(size, buf);
                if (!ret) {
                        cerr << "ERROR: Read time/size but not buffer, corrupt MIDI ring buffer" << endl;
                        break;
                }
                
-               assert(time >= _timeline_position);
-               time -= _timeline_position;
+               assert(time >= position);
+               time -= position;
                
                ev.set(buf, size, time);
                ev.set_event_type(EventTypeMap::instance().midi_event_type(ev.buffer()[0]));
-               if (! (ev.is_channel_event() || ev.is_smf_meta_event() || ev.is_sysex()) ) {
-                       cerr << "SMFSource: WARNING: caller tried to write non SMF-Event of type " << std::hex << int(ev.buffer()[0]) << endl;
+               if (!(ev.is_channel_event() || ev.is_smf_meta_event() || ev.is_sysex())) {
+                       cerr << "SMFSource: WARNING: caller tried to write non SMF-Event of type "
+                                       << std::hex << int(ev.buffer()[0]) << endl;
                        continue;
                }
                
-               append_event_unlocked(Frames, ev);
-
-               if (_model) {
-                       _model->append(ev);
-               }
+               append_event_unlocked_frames(ev, position);
        }
 
        if (_model) {
                set_default_controls_interpolation();
        }
 
-       Evoral::SMF<double>::flush();
+       Evoral::SMF::flush();
        free(buf);
 
-       const nframes_t oldlen = _length;
-       update_length(oldlen, cnt);
+       ViewDataRangeReady(position + _last_write_end, duration); /* EMIT SIGNAL */
 
-       ViewDataRangeReady (_timeline_position + oldlen, cnt); /* EMIT SIGNAL */
-       
-       return cnt;
+       return duration;
 }
                
 
+/** Append an event with a timestamp in beats (double) */
 void
-SMFSource::append_event_unlocked(EventTimeUnit unit, const Evoral::Event<double>& ev)
+SMFSource::append_event_unlocked_beats (const Evoral::Event<double>& ev)
 {
        if (ev.size() == 0)  {
-               cerr << "SMFSource: Warning: skipping empty event" << endl;
                return;
        }
 
-       /*
-       printf("SMFSource: %s - append_event_unlocked time = %lf, size = %u, data = ",
+       /*printf("SMFSource: %s - append_event_unlocked_beats time = %lf, size = %u, data = ",
                        name().c_str(), ev.time(), ev.size()); 
-       for (size_t i=0; i < ev.size(); ++i) {
-               printf("%X ", ev.buffer()[i]);
-       }
-       printf("\n");
-       */
+       for (size_t i = 0; i < ev.size(); ++i) printf("%X ", ev.buffer()[i]); printf("\n");*/
        
        assert(ev.time() >= 0);
-       
-       if (ev.time() < last_event_time()) {
-               cerr << "SMFSource: Warning: Skipping event with ev.time() < last.time()" << endl;
+       if (ev.time() < _last_ev_time_beats) {
+               cerr << "SMFSource: Warning: Skipping event with non-monotonic time" << endl;
                return;
        }
        
-       uint32_t delta_time = 0;
+       _length_beats = max(_length_beats, ev.time());
        
-       if (unit == Frames) {
-               // FIXME: assumes tempo never changes after start
-               const double frames_per_beat = _session.tempo_map().tempo_at(_timeline_position).frames_per_beat(
-                               _session.engine().frame_rate(),
-                               _session.tempo_map().meter_at(_timeline_position));
+       const double delta_time_beats   = ev.time() - _last_ev_time_beats;
+       const uint32_t delta_time_ticks = (uint32_t)lrint(delta_time_beats * (double)ppqn());
+       
+       Evoral::SMF::append_event_delta(delta_time_ticks, ev.size(), ev.buffer());
+       _last_ev_time_beats = ev.time();
 
-               delta_time = (uint32_t)((ev.time() - last_event_time()) / frames_per_beat * ppqn());
-       } else {
-               assert(unit == Beats);
-               delta_time = (uint32_t)((ev.time() - last_event_time()) * ppqn());
+       _write_data_count += ev.size();
+
+       if (_model) {
+               _model->append(ev);
        }
+}
 
-       Evoral::SMF<double>::append_event_delta(delta_time, ev.size(), ev.buffer());
-       _last_ev_time = ev.time();
+/** Append an event with a timestamp in frames (nframes_t) */
+void
+SMFSource::append_event_unlocked_frames (const Evoral::Event<nframes_t>& ev, sframes_t position)
+{
+       if (ev.size() == 0)  {
+               return;
+       }
+
+       /*printf("SMFSource: %s - append_event_unlocked_frames time = %u, size = %u, data = ",
+                       name().c_str(), ev.time(), ev.size()); 
+       for (size_t i=0; i < ev.size(); ++i) printf("%X ", ev.buffer()[i]); printf("\n");*/
+       
+       if (ev.time() < _last_ev_time_frames) {
+               cerr << "SMFSource: Warning: Skipping event with non-monotonic time" << endl;
+               return;
+       }
+       
+       BeatsFramesConverter converter(_session, position);
+       
+       _length_beats = max(_length_beats, converter.from(ev.time()));
+       
+       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()));
+
+       Evoral::SMF::append_event_delta(delta_time_ticks, ev.size(), ev.buffer());
+       _last_ev_time_frames = ev.time();
 
        _write_data_count += ev.size();
-}
 
+       if (_model) {
+               const double ev_time_beats = converter.from(ev.time());
+               const Evoral::Event<double> beat_ev(
+                               ev.event_type(), ev_time_beats, ev.size(), (uint8_t*)ev.buffer());
+               _model->append(beat_ev);
+       }
+}
 
 XMLNode&
 SMFSource::get_state ()
 {
-       XMLNode& root (MidiSource::get_state());
-       char buf[16];
-       snprintf (buf, sizeof (buf), "0x%x", (int)_flags);
-       root.add_property ("flags", buf);
-       return root;
+       return MidiSource::get_state();
 }
 
 int
 SMFSource::set_state (const XMLNode& node)
 {
-       const XMLProperty* prop;
+       if (Source::set_state (node)) {
+               return -1;
+       }
 
        if (MidiSource::set_state (node)) {
                return -1;
        }
-
-       if ((prop = node.property (X_("flags"))) != 0) {
-
-               int ival;
-               sscanf (prop->value().c_str(), "0x%x", &ival);
-               _flags = Flag (ival);
-
-       } else {
-
-               _flags = Flag (0);
-
+       
+       if (FileSource::set_state (node)) {
+               return -1;
        }
 
-       assert(_name.find("/") == string::npos);
-
        return 0;
 }
 
 void
-SMFSource::mark_for_remove ()
-{
-       if (!writable()) {
-               return;
-       }
-       _flags = Flag (_flags | RemoveAtDestroy);
-}
-
-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<double>::begin_write ();
-       _last_ev_time = 0;
+       Evoral::SMF::begin_write ();
+       _last_ev_time_beats = 0.0;
+       _last_ev_time_frames = 0;
 }
 
 void
@@ -373,247 +350,17 @@ SMFSource::mark_streaming_write_completed ()
        }
        
        _model->set_edited(false);
-       Evoral::SMF<double>::end_write ();
-}
-
-void
-SMFSource::mark_take (string id)
-{
-       if (writable()) {
-               _take_id = id;
-       }
-}
-
-int
-SMFSource::move_to_trash (const string trash_dir_name)
-{
-       string newpath;
-
-       if (!writable()) {
-               return -1;
-       }
-
-       /* don't move the file across filesystems, just
-          stick it in the 'trash_dir_name' directory
-          on whichever filesystem it was already on.
-       */
-
-       newpath = Glib::path_get_dirname (_path);
-       newpath = Glib::path_get_dirname (newpath);
-
-       newpath += '/';
-       newpath += trash_dir_name;
-       newpath += '/';
-       newpath += Glib::path_get_basename (_path);
-
-       if (access (newpath.c_str(), F_OK) == 0) {
-
-               /* the new path already exists, try versioning */
-               
-               char buf[PATH_MAX+1];
-               int version = 1;
-               string newpath_v;
-
-               snprintf (buf, sizeof (buf), "%s.%d", newpath.c_str(), version);
-               newpath_v = buf;
-
-               while (access (newpath_v.c_str(), F_OK) == 0 && version < 999) {
-                       snprintf (buf, sizeof (buf), "%s.%d", newpath.c_str(), ++version);
-                       newpath_v = buf;
-               }
-               
-               if (version == 999) {
-                       PBD::error << string_compose (_("there are already 1000 files with names like %1; versioning discontinued"),
-                                         newpath)
-                             << endmsg;
-               } else {
-                       newpath = newpath_v;
-               }
-
-       } else {
-
-               /* it doesn't exist, or we can't read it or something */
-
-       }
-
-       if (::rename (_path.c_str(), newpath.c_str()) != 0) {
-               PBD::error << string_compose (_("cannot rename midi file source from %1 to %2 (%3)"),
-                                 _path, newpath, strerror (errno))
-                     << endmsg;
-               return -1;
-       }
-#if 0
-       if (::unlink (peakpath.c_str()) != 0) {
-               PBD::error << string_compose (_("cannot remove peakfile %1 for %2 (%3)"),
-                                 peakpath, _path, strerror (errno))
-                     << endmsg;
-               /* try to back out */
-               rename (newpath.c_str(), _path.c_str());
-               return -1;
-       }
-           
-       _path = newpath;
-       peakpath = "";
-#endif 
-       /* file can not be removed twice, since the operation is not idempotent */
-
-       _flags = Flag (_flags & ~(RemoveAtDestroy|Removable|RemovableIfEmpty));
-
-       return 0;
+       Evoral::SMF::end_write ();
 }
 
 bool
-SMFSource::safe_file_extension(const Glib::ustring& file)
+SMFSource::safe_midi_file_extension (const Glib::ustring& file)
 {
        return (file.rfind(".mid") != Glib::ustring::npos);
 }
 
-// FIXME: Merge this with audiofilesource somehow (make a generic filesource?)
-bool
-SMFSource::find (string pathstr, bool must_exist, bool& isnew)
-{
-       string::size_type pos;
-       bool ret = false;
-
-       isnew = false;
-
-       /* clean up PATH:CHANNEL notation so that we are looking for the correct path */
-
-       if ((pos = pathstr.find_last_of (':')) == string::npos) {
-               pathstr = pathstr;
-       } else {
-               pathstr = pathstr.substr (0, pos);
-       }
-
-       if (pathstr[0] != '/') {
-
-               /* non-absolute pathname: find pathstr in search path */
-
-               vector<string> dirs;
-               int cnt;
-               string fullpath;
-               string keeppath;
-
-               if (_search_path.length() == 0) {
-                       PBD::error << _("FileSource: search path not set") << endmsg;
-                       goto out;
-               }
-
-               split (_search_path, dirs, ':');
-
-               cnt = 0;
-               
-               for (vector<string>::iterator i = dirs.begin(); i != dirs.end(); ++i) {
-
-                       fullpath = *i;
-                       if (fullpath[fullpath.length()-1] != '/') {
-                               fullpath += '/';
-                       }
-                       fullpath += pathstr;
-                       
-                       if (access (fullpath.c_str(), R_OK) == 0) {
-                               keeppath = fullpath;
-                               ++cnt;
-                       } 
-               }
-
-               if (cnt > 1) {
-
-                       PBD::error << string_compose (_("FileSource: \"%1\" is ambigous when searching %2\n\t"), pathstr, _search_path) << endmsg;
-                       goto out;
-
-               } else if (cnt == 0) {
-
-                       if (must_exist) {
-                               PBD::error << string_compose(_("Filesource: cannot find required file (%1): while searching %2"), pathstr, _search_path) << endmsg;
-                               goto out;
-                       } else {
-                               isnew = true;
-                       }
-               }
-               
-               _name = pathstr;
-               _path = keeppath;
-               ret = true;
-
-       } else {
-               
-               /* external files and/or very very old style sessions include full paths */
-               
-               _path = pathstr;
-               _name = pathstr.substr (pathstr.find_last_of ('/') + 1);
-               
-               if (access (_path.c_str(), R_OK) != 0) {
-
-                       /* file does not exist or we cannot read it */
-
-                       if (must_exist) {
-                               PBD::error << string_compose(_("Filesource: cannot find required file (%1): %2"), _path, strerror (errno)) << endmsg;
-                               goto out;
-                       }
-                       
-                       if (errno != ENOENT) {
-                               PBD::error << string_compose(_("Filesource: cannot check for existing file (%1): %2"), _path, strerror (errno)) << endmsg;
-                               goto out;
-                       }
-                       
-                       /* a new file */
-
-                       isnew = true;
-                       ret = true;
-
-               } else {
-                       
-                       /* already exists */
-
-                       ret = true;
-               }
-       }
-       
-  out:
-       return ret;
-}
-
-void
-SMFSource::set_search_path (string p)
-{
-       _search_path = p;
-}
-
-
 void
-SMFSource::set_allow_remove_if_empty (bool yn)
-{
-       if (writable()) {
-               _allow_remove_if_empty = yn;
-       }
-}
-
-int
-SMFSource::set_source_name (string newname, bool destructive)
-{
-       //Glib::Mutex::Lock lm (_lock); FIXME
-       string oldpath = _path;
-       string newpath = Session::change_midi_path_by_name (oldpath, _name, newname, destructive);
-
-       if (newpath.empty()) {
-               PBD::error << string_compose (_("programming error: %1"), "cannot generate a changed midi path") << endmsg;
-               return -1;
-       }
-
-       if (rename (oldpath.c_str(), newpath.c_str()) != 0) {
-               PBD::error << string_compose (_("cannot rename midi file for %1 to %2"), _name, newpath) << endmsg;
-               return -1;
-       }
-
-       _name = Glib::path_get_basename (newpath);
-       _path = newpath;
-
-       return 0;//rename_peakfile (peak_path (_path));
-}
-
-void
-SMFSource::load_model(bool lock, bool force_reload)
+SMFSource::load_model (bool lock, bool force_reload)
 {
        if (_writing) {
                return;
@@ -623,53 +370,46 @@ SMFSource::load_model(bool lock, bool force_reload)
                Glib::Mutex::Lock lm (_lock);
        }
 
-       if (_model && !force_reload && !_model->empty()) {
+       if (_model && !force_reload) {
                return;
        }
 
        if (! _model) {
                _model = boost::shared_ptr<MidiModel>(new MidiModel(this));
-               cerr << _name << " loaded new model " << _model.get() << endl;
+               //cerr << _name << " loaded new model " << _model.get() << endl;
        } else {
-               cerr << _name << " reloading model " << _model.get()
-                       << " (" << _model->n_notes() << " notes)" <<endl;
+               /*cerr << _name << " reloading model " << _model.get()
+                       << " (" << _model->n_notes() << " notes)" << endl;*/
                _model->clear();
        }
 
        _model->start_write();
-       Evoral::SMF<double>::seek_to_start();
+       Evoral::SMF::seek_to_start();
 
        uint64_t time = 0; /* in SMF ticks */
        Evoral::Event<double> ev;
        
        size_t scratch_size = 0; // keep track of scratch and minimize reallocs
        
-       // FIXME: assumes tempo never changes after start
-       const double frames_per_beat = _session.tempo_map().tempo_at(_timeline_position).frames_per_beat(
-                       _session.engine().frame_rate(),
-                       _session.tempo_map().meter_at(_timeline_position));
-       
        uint32_t delta_t = 0;
        uint32_t size    = 0;
        uint8_t* buf     = NULL;
        int ret;
        while ((ret = read_event(&delta_t, &size, &buf)) >= 0) {
-               
-               ev.set(buf, size, 0.0);
                time += delta_t;
-               
+               ev.set(buf, size, time / (double)ppqn());
+
                if (ret > 0) { // didn't skip (meta) event
-                       // make ev.time absolute time in frames
-                       ev.time() = time * frames_per_beat / (double)ppqn();
                        ev.set_event_type(EventTypeMap::instance().midi_event_type(buf[0]));
                        _model->append(ev);
                }
 
                if (ev.size() > scratch_size) {
                        scratch_size = ev.size();
-               } else {
-                       ev.size() = scratch_size;
                }
+               ev.size() = scratch_size; // ensure read_event only allocates if necessary
+               
+               _length_beats = max(_length_beats, ev.time());
        }
 
        set_default_controls_interpolation();
@@ -677,13 +417,15 @@ SMFSource::load_model(bool lock, bool force_reload)
        _model->end_write(false);
        _model->set_edited(false);
 
+       _model_iter = _model->begin();
+
        free(buf);
 }
 
 #define LINEAR_INTERPOLATION_MODE_WORKS_PROPERLY 0
 
 void
-SMFSource::set_default_controls_interpolation()
+SMFSource::set_default_controls_interpolation ()
 {
        // set interpolation style to defaults, can be changed by the GUI later
        Evoral::ControlSet::Controls controls = _model->controls();
@@ -700,15 +442,15 @@ SMFSource::set_default_controls_interpolation()
 
 
 void
-SMFSource::destroy_model()
+SMFSource::destroy_model ()
 {
        //cerr << _name << " destroying model " << _model.get() << endl;
        _model.reset();
 }
 
 void
-SMFSource::flush_midi()
+SMFSource::flush_midi ()
 {
-       Evoral::SMF<double>::end_write();
+       Evoral::SMF::end_write();
 }