detect buffer "overflow" when delivering immediate events and queue remainder for...
[ardour.git] / libs / ardour / midi_track.cc
index aff7ed4d15745bc39bc12746aa544763edbe8747..07b6d2ac6d127cb2c178bbc36700d526b3b05db6 100644 (file)
@@ -1,6 +1,6 @@
 /*
-    Copyright (C) 2006 Paul Davis 
-       By Dave Robillard, 2006
+    Copyright (C) 2006 Paul Davis
+    Author: David Robillard
 
     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
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
-#include <pbd/error.h>
-#include <sigc++/retype.h>
-#include <sigc++/retype_return.h>
-#include <sigc++/bind.h>
-
-#include <pbd/enumwriter.h>
-#include <midi++/events.h>
-#include <evoral/midi_util.h>
-
-#include <ardour/midi_track.h>
-#include <ardour/midi_diskstream.h>
-#include <ardour/session.h>
-#include <ardour/io_processor.h>
-#include <ardour/midi_region.h>
-#include <ardour/midi_source.h>
-#include <ardour/route_group_specialized.h>
-#include <ardour/processor.h>
-#include <ardour/midi_playlist.h>
-#include <ardour/panner.h>
-#include <ardour/utils.h>
-#include <ardour/buffer_set.h>
-#include <ardour/meter.h>
 
+#include "pbd/error.h"
+
+#include "pbd/enumwriter.h"
+#include "pbd/convert.h"
+#include "midi++/events.h"
+#include "evoral/midi_util.h"
+
+#include "ardour/amp.h"
+#include "ardour/buffer_set.h"
+#include "ardour/debug.h"
+#include "ardour/delivery.h"
+#include "ardour/io_processor.h"
+#include "ardour/meter.h"
+#include "ardour/midi_diskstream.h"
+#include "ardour/midi_playlist.h"
+#include "ardour/midi_port.h"
+#include "ardour/midi_region.h"
+#include "ardour/midi_source.h"
+#include "ardour/midi_track.h"
+#include "ardour/panner.h"
+#include "ardour/port.h"
+#include "ardour/processor.h"
+#include "ardour/route_group_specialized.h"
+#include "ardour/session.h"
+#include "ardour/session_playlists.h"
+#include "ardour/utils.h"
 
 #include "i18n.h"
 
@@ -49,7 +53,19 @@ using namespace PBD;
 MidiTrack::MidiTrack (Session& sess, string name, Route::Flag flag, TrackMode mode)
        : Track (sess, name, flag, mode, DataType::MIDI)
        , _immediate_events(1024) // FIXME: size?
+       , _step_edit_ring_buffer(64) // FIXME: size?
        , _note_mode(Sustained)
+       , _step_editing (false)
+       , _midi_thru (true)
+{
+}
+
+MidiTrack::~MidiTrack ()
+{
+}
+
+void
+MidiTrack::use_new_diskstream ()
 {
        MidiDiskstream::Flag dflags = MidiDiskstream::Flag (0);
 
@@ -59,88 +75,43 @@ MidiTrack::MidiTrack (Session& sess, string name, Route::Flag flag, TrackMode mo
                dflags = MidiDiskstream::Flag (dflags | MidiDiskstream::Recordable);
        }
 
-       assert(mode != Destructive);
+       assert(_mode != Destructive);
 
-       boost::shared_ptr<MidiDiskstream> ds (new MidiDiskstream (_session, name, dflags));
-       _session.add_diskstream (ds);
+       boost::shared_ptr<MidiDiskstream> ds (new MidiDiskstream (_session, name(), dflags));
+       ds->do_refill_with_alloc ();
+       ds->set_block_size (_session.get_block_size ());
 
-       set_diskstream (boost::dynamic_pointer_cast<MidiDiskstream> (ds));
-       
-       _declickable = true;
-       _freeze_record.state = NoFreeze;
-       _saved_meter_point = _meter_point;
-       _mode = mode;
-
-       set_input_minimum(ChanCount(DataType::MIDI, 1));
-       set_input_maximum(ChanCount(DataType::MIDI, 1));
-       set_output_minimum(ChanCount(DataType::MIDI, 1));
-       set_output_maximum(ChanCount(DataType::MIDI, 1));
-
-       PortCountChanged(ChanCount(DataType::MIDI, 2)); /* EMIT SIGNAL */
+       set_diskstream (ds);
 }
 
-MidiTrack::MidiTrack (Session& sess, const XMLNode& node)
-       : Track (sess, node, DataType::MIDI )
-       , _immediate_events(1024) // FIXME: size?
-       , _note_mode(Sustained)
+void
+MidiTrack::set_record_enabled (bool yn, void *src)
 {
-       _set_state(node, false);
-       
-       set_input_minimum(ChanCount(DataType::MIDI, 1));
-       set_input_maximum(ChanCount(DataType::MIDI, 1));
-       set_output_minimum(ChanCount(DataType::MIDI, 1));
-       set_output_maximum(ChanCount(DataType::MIDI, 1));
-       
-       PortCountChanged(ChanCount(DataType::MIDI, 2)); /* EMIT SIGNAL */
-}
+       if (_step_editing) {
+               return;
+       }
 
-MidiTrack::~MidiTrack ()
-{
+       Track::set_record_enabled (yn, src);
 }
 
-
-int
-MidiTrack::set_diskstream (boost::shared_ptr<MidiDiskstream> ds)
+void
+MidiTrack::set_diskstream (boost::shared_ptr<Diskstream> ds)
 {
-       _diskstream = ds;
-       _diskstream->set_io (*this);
+       Track::set_diskstream (ds);
+       
+       _diskstream->set_track (this);
        _diskstream->set_destructive (_mode == Destructive);
 
        _diskstream->set_record_enabled (false);
        //_diskstream->monitor_input (false);
 
-       ic_connection.disconnect();
-       ic_connection = input_changed.connect (mem_fun (*_diskstream, &MidiDiskstream::handle_input_change));
+       _diskstream_data_recorded_connection.disconnect ();
+       boost::shared_ptr<MidiDiskstream> mds = boost::dynamic_pointer_cast<MidiDiskstream> (ds);
+       mds->DataRecorded.connect_same_thread (
+               _diskstream_data_recorded_connection,
+               boost::bind (&MidiTrack::diskstream_data_recorded, this, _1, _2));
 
        DiskstreamChanged (); /* EMIT SIGNAL */
-
-       return 0;
-}      
-
-int 
-MidiTrack::use_diskstream (string name)
-{
-       boost::shared_ptr<MidiDiskstream> dstream;
-
-       if ((dstream = boost::dynamic_pointer_cast<MidiDiskstream>(_session.diskstream_by_name (name))) == 0) {
-               error << string_compose(_("MidiTrack: midi diskstream \"%1\" not known by session"), name) << endmsg;
-               return -1;
-       }
-       
-       return set_diskstream (dstream);
-}
-
-int 
-MidiTrack::use_diskstream (const PBD::ID& id)
-{
-       boost::shared_ptr<MidiDiskstream> dstream;
-
-       if ((dstream = boost::dynamic_pointer_cast<MidiDiskstream> (_session.diskstream_by_id (id))) == 0) {
-               error << string_compose(_("MidiTrack: midi diskstream \"%1\" not known by session"), id) << endmsg;
-               return -1;
-       }
-       
-       return set_diskstream (dstream);
 }
 
 boost::shared_ptr<MidiDiskstream>
@@ -150,76 +121,75 @@ MidiTrack::midi_diskstream() const
 }
 
 int
-MidiTrack::set_state (const XMLNode& node)
+MidiTrack::set_state (const XMLNode& node, int version)
 {
-       return _set_state (node, true);
+       return _set_state (node, version, true);
 }
 
 int
-MidiTrack::_set_state (const XMLNode& node, bool call_base)
+MidiTrack::_set_state (const XMLNode& node, int version, bool call_base)
 {
        const XMLProperty *prop;
        XMLNodeConstIterator iter;
 
-       if (Route::_set_state (node, call_base)) {
+       if (Route::_set_state (node, version, call_base)) {
                return -1;
        }
-       
+
        // No destructive MIDI tracks (yet?)
        _mode = Normal;
-       
+
        if ((prop = node.property (X_("note-mode"))) != 0) {
                _note_mode = NoteMode (string_2_enum (prop->value(), _note_mode));
        } else {
                _note_mode = Sustained;
        }
 
-       if ((prop = node.property ("diskstream-id")) == 0) {
-               
-               /* some old sessions use the diskstream name rather than the ID */
-
-               if ((prop = node.property ("diskstream")) == 0) {
-                       fatal << _("programming error: MidiTrack given state without diskstream!") << endmsg;
-                       /*NOTREACHED*/
-                       return -1;
-               }
-
-               if (use_diskstream (prop->value())) {
-                       return -1;
-               }
-
-       } else {
-               
-               PBD::ID id (prop->value());
-               
-               if (use_diskstream (id)) {
-                       return -1;
-               }
+       if ((prop = node.property ("midi-thru")) != 0) {
+               set_midi_thru (prop->value() == "yes");
        }
 
-
        XMLNodeList nlist;
        XMLNodeConstIterator niter;
        XMLNode *child;
 
        nlist = node.children();
+
+       if (version >= 3000) {
+               if ((child = find_named_node (node, X_("Diskstream"))) != 0) {
+                       boost::shared_ptr<MidiDiskstream> ds (new MidiDiskstream (_session, *child));
+                       ds->do_refill_with_alloc ();
+                       set_diskstream (ds);
+               }
+       }
+
+       /* set rec-enable control *AFTER* setting up diskstream, because it may
+          want to operate on the diskstream as it sets its own state
+       */
+
        for (niter = nlist.begin(); niter != nlist.end(); ++niter){
                child = *niter;
 
-               if (child->name() == X_("recenable")) {
-                       _rec_enable_control->set_state (*child);
-                       _session.add_controllable (_rec_enable_control);
+               if (child->name() == Controllable::xml_node_name && (prop = child->property ("name")) != 0) {
+                       if (prop->value() == X_("recenable")) {
+                               _rec_enable_control->set_state (*child, version);
+                       }
                }
        }
 
        pending_state = const_cast<XMLNode*> (&node);
 
-       _session.StateReady.connect (mem_fun (*this, &MidiTrack::set_state_part_two));
+       if (_session.state_of_the_state() & Session::Loading) {
+               _session.StateReady.connect_same_thread (
+                       *this, boost::bind (&MidiTrack::set_state_part_two, this));
+       } else {
+               set_state_part_two ();
+       }
 
        return 0;
 }
 
-XMLNode& 
+XMLNode&
 MidiTrack::state(bool full_state)
 {
        XMLNode& root (Route::state(full_state));
@@ -238,32 +208,20 @@ MidiTrack::state(bool full_state)
                        (*i)->id.print (buf, sizeof(buf));
                        inode->add_property (X_("id"), buf);
                        inode->add_child_copy ((*i)->state);
-               
+
                        freeze_node->add_child_nocopy (*inode);
                }
 
                root.add_child_nocopy (*freeze_node);
        }
 
-       /* Alignment: act as a proxy for the diskstream */
-       
-       XMLNode* align_node = new XMLNode (X_("Alignment"));
-       AlignStyle as = _diskstream->alignment_style ();
-       align_node->add_property (X_("style"), enum_2_string (as));
-       root.add_child_nocopy (*align_node);
-
        root.add_property (X_("note-mode"), enum_2_string (_note_mode));
-       
-       /* we don't return diskstream state because we don't
-          own the diskstream exclusively. control of the diskstream
-          state is ceded to the Session, even if we create the
-          diskstream.
-       */
-
-       _diskstream->id().print (buf, sizeof(buf));
-       root.add_property ("diskstream-id", buf);
-       
        root.add_child_nocopy (_rec_enable_control->get_state());
+       root.add_child_nocopy (_diskstream->get_state ());
+
+       root.add_property ("step-editing", (_step_editing ? "yes" : "no"));
+       root.add_property ("note-mode", enum_2_string (_note_mode));
+       root.add_property ("midi-thru", (_midi_thru ? "yes" : "no"));
 
        return root;
 }
@@ -285,17 +243,15 @@ MidiTrack::set_state_part_two ()
 
        if ((fnode = find_named_node (*pending_state, X_("freeze-info"))) != 0) {
 
-               
-               _freeze_record.have_mementos = false;
                _freeze_record.state = Frozen;
-               
+
                for (vector<FreezeRecordProcessorInfo*>::iterator i = _freeze_record.processor_info.begin(); i != _freeze_record.processor_info.end(); ++i) {
                        delete *i;
                }
                _freeze_record.processor_info.clear ();
-               
+
                if ((prop = fnode->property (X_("playlist"))) != 0) {
-                       boost::shared_ptr<Playlist> pl = _session.playlist_by_name (prop->value());
+                       boost::shared_ptr<Playlist> pl = _session.playlists->by_name (prop->value());
                        if (pl) {
                                _freeze_record.playlist = boost::dynamic_pointer_cast<MidiPlaylist> (pl);
                        } else {
@@ -304,23 +260,23 @@ MidiTrack::set_state_part_two ()
                        return;
                        }
                }
-               
+
                if ((prop = fnode->property (X_("state"))) != 0) {
                        _freeze_record.state = FreezeState (string_2_enum (prop->value(), _freeze_record.state));
                }
-               
+
                XMLNodeConstIterator citer;
                XMLNodeList clist = fnode->children();
-               
+
                for (citer = clist.begin(); citer != clist.end(); ++citer) {
                        if ((*citer)->name() != X_("processor")) {
                                continue;
                        }
-                       
+
                        if ((prop = (*citer)->property (X_("id"))) == 0) {
                                continue;
                        }
-                       
+
                        FreezeRecordProcessorInfo* frii = new FreezeRecordProcessorInfo (*((*citer)->children().front()),
                                                                                   boost::shared_ptr<Processor>());
                        frii->id = prop->value ();
@@ -328,175 +284,66 @@ MidiTrack::set_state_part_two ()
                }
        }
 
-       /* Alignment: act as a proxy for the diskstream */
-
-       if ((fnode = find_named_node (*pending_state, X_("Alignment"))) != 0) {
-
-               if ((prop = fnode->property (X_("style"))) != 0) {
-
-                       /* fix for older sessions from before EnumWriter */
-
-                       string pstr;
-
-                       if (prop->value() == "capture") {
-                               pstr = "CaptureTime";
-                       } else if (prop->value() == "existing") {
-                               pstr = "ExistingMaterial";
-                       } else {
-                               pstr = prop->value();
-                       }
-
-                       AlignStyle as = AlignStyle (string_2_enum (pstr, as));
-                       _diskstream->set_persistent_align_style (as);
-               }
+       if (midi_diskstream ()) {
+               midi_diskstream()->set_block_size (_session.get_block_size ());
        }
+
        return;
-}      
+}
 
-int 
-MidiTrack::no_roll (nframes_t nframes, nframes_t start_frame, nframes_t end_frame, nframes_t offset, 
-                    bool session_state_changing, bool can_record, bool rec_monitors_input)
+int
+MidiTrack::roll (pframes_t nframes, framepos_t start_frame, framepos_t end_frame, int declick,
+                bool can_record, bool rec_monitors_input, bool& needs_butler)
 {
-       if (n_outputs().n_midi() == 0) {
+       Glib::RWLock::ReaderLock lm (_processor_lock, Glib::TRY_LOCK);
+       if (!lm.locked()) {
                return 0;
        }
 
-       if (!_active) {
-               silence (nframes, offset);
-       }
-
-       if (session_state_changing) {
-
-               /* XXX is this safe to do against transport state changes? */
-
-               passthru_silence (start_frame, end_frame, nframes, offset, 0, false);
-               return 0;
-       }
-
-       midi_diskstream()->check_record_status (start_frame, nframes, can_record);
-
-       bool send_silence;
-       
-       if (_have_internal_generator) {
-               /* since the instrument has no input streams,
-                  there is no reason to send any signal
-                  into the route.
-               */
-               send_silence = true;
-       } else {
-
-               if (Config->get_auto_input()) {
-                       if (Config->get_monitoring_model() == SoftwareMonitoring) {
-                               send_silence = false;
-                       } else {
-                               send_silence = true;
-                       }
-               } else {
-                       if (_diskstream->record_enabled()) {
-                               if (Config->get_monitoring_model() == SoftwareMonitoring) {
-                                       send_silence = false;
-                               } else {
-                                       send_silence = true;
-                               }
-                       } else {
-                               send_silence = true;
-                       }
-               }
-       }
-
-       apply_gain_automation = false;
-
-       if (send_silence) {
-               
-               /* if we're sending silence, but we want the meters to show levels for the signal,
-                  meter right here.
-               */
-               
-               if (_have_internal_generator) {
-                       passthru_silence (start_frame, end_frame, nframes, offset, 0, true);
-               } else {
-                       if (_meter_point == MeterInput) {
-                               just_meter_input (start_frame, end_frame, nframes, offset);
-                       }
-                       passthru_silence (start_frame, end_frame, nframes, offset, 0, false);
-               }
-
-       } else {
-       
-               /* we're sending signal, but we may still want to meter the input. 
-                */
-
-               passthru (start_frame, end_frame, nframes, offset, 0, (_meter_point == MeterInput));
-       }
-       
-       flush_outputs( nframes, offset );
-
-       return 0;
-}
-
-int
-MidiTrack::roll (nframes_t nframes, nframes_t start_frame, nframes_t end_frame, nframes_t offset, int declick,
-                 bool can_record, bool rec_monitors_input)
-{
        int dret;
        boost::shared_ptr<MidiDiskstream> diskstream = midi_diskstream();
-       
-       // I guess this is the right place to call cycle_start for our ports.
-       // but it actually sucks, to directly mess with the IO.... oh well.
-       
-       prepare_inputs( nframes, offset );
-
-       {
-               Glib::RWLock::ReaderLock lm (_processor_lock, Glib::TRY_LOCK);
-               if (lm.locked()) {
-                       // automation snapshot can also be called from the non-rt context
-                       // and it uses the redirect list, so we take the lock out here
-                       automation_snapshot (start_frame);
-               }
-       }
+
+       automation_snapshot (start_frame);
 
        if (n_outputs().n_total() == 0 && _processors.empty()) {
                return 0;
        }
 
        if (!_active) {
-               silence (nframes, offset);
+               silence (nframes);
                return 0;
        }
 
-       nframes_t transport_frame = _session.transport_frame();
+       framepos_t transport_frame = _session.transport_frame();
 
-       
-       if ((nframes = check_initial_delay (nframes, offset, transport_frame)) == 0) {
+       if ((nframes = check_initial_delay (nframes, transport_frame)) == 0) {
                /* need to do this so that the diskstream sets its
                   playback distance to zero, thus causing diskstream::commit
                   to do nothing.
                   */
-               return diskstream->process (transport_frame, 0, 0, can_record, rec_monitors_input);
-       } 
+               return diskstream->process (transport_frame, 0, can_record, rec_monitors_input, needs_butler);
+       }
 
        _silent = false;
 
-       if ((dret = diskstream->process (transport_frame, nframes, offset, can_record, rec_monitors_input)) != 0) {
-
-               silence (nframes, offset);
-
+       if ((dret = diskstream->process (transport_frame, nframes, can_record, rec_monitors_input, needs_butler)) != 0) {
+               silence (nframes);
                return dret;
        }
 
        /* special condition applies */
 
        if (_meter_point == MeterInput) {
-               just_meter_input (start_frame, end_frame, nframes, offset);
+               _input->process_input (_meter, start_frame, end_frame, nframes);
        }
 
-       if (diskstream->record_enabled() && !can_record && !Config->get_auto_input()) {
+       if (diskstream->record_enabled() && !can_record && !_session.config.get_auto_input()) {
 
                /* not actually recording, but we want to hear the input material anyway,
                   at least potentially (depending on monitoring options)
-                  */
+               */
 
-               passthru (start_frame, end_frame, nframes, offset, 0, true);
+               passthru (start_frame, end_frame, nframes, 0);
 
        } else {
                /*
@@ -512,103 +359,123 @@ MidiTrack::roll (nframes_t nframes, nframes_t start_frame, nframes_t end_frame,
 
                //const size_t limit = n_process_buffers().n_audio();
                BufferSet& bufs = _session.get_scratch_buffers (n_process_buffers());
+               MidiBuffer& mbuf (bufs.get_midi (0));
 
-               diskstream->get_playback(bufs.get_midi(0), start_frame, end_frame, offset);
+               /* we are a MIDI track, so we always start the chain with a single-channel diskstream */
+               ChanCount c;
+               c.set_audio (0);
+               c.set_midi (1);
+               bufs.set_count (c);
 
-               process_output_buffers (bufs, start_frame, end_frame, nframes, offset,
-                               (!_session.get_record_enabled() || !Config->get_do_not_record_plugins()), declick, (_meter_point != MeterInput));
-       
+               diskstream->get_playback (mbuf, start_frame, end_frame);
+
+               /* append immediate messages to the first MIDI buffer (thus sending it to the first output port) */
+
+               write_out_of_band_data (bufs, start_frame, end_frame, nframes);
+
+               /* final argument: don't waste time with automation if we're recording or we've just stopped (yes it can happen) */
+
+               process_output_buffers (bufs, start_frame, end_frame, nframes,
+                                       (!_session.get_record_enabled() || !Config->get_do_not_record_plugins()), declick,
+                                       (!diskstream->record_enabled() && !_session.transport_stopped()));
        }
 
-       flush_outputs( nframes, offset );
+       _main_outs->flush_buffers (nframes, end_frame - start_frame - 1);
 
        return 0;
 }
 
 int
-MidiTrack::silent_roll (nframes_t nframes, nframes_t start_frame, nframes_t end_frame, nframes_t offset, 
-                        bool can_record, bool rec_monitors_input)
+MidiTrack::no_roll (pframes_t nframes, framepos_t start_frame, framepos_t end_frame,
+                   bool state_changing, bool can_record, bool rec_monitors_input)
 {
-       if (n_outputs().n_midi() == 0 && _processors.empty()) {
-               return 0;
-       }
+       int ret = Track::no_roll (nframes, start_frame, end_frame, state_changing, can_record, rec_monitors_input);
 
-       if (!_active) {
-               silence (nframes, offset);
-               return 0;
+       if (ret == 0 && _step_editing) {
+               push_midi_input_to_step_edit_ringbuffer (nframes);
        }
 
-       _silent = true;
-       apply_gain_automation = false;
-
-       silence (nframes, offset);
-
-       return midi_diskstream()->process (_session.transport_frame() + offset, nframes, offset, can_record, rec_monitors_input);
+       return ret;
 }
 
 void
-MidiTrack::process_output_buffers (BufferSet& bufs,
-                              nframes_t start_frame, nframes_t end_frame, 
-                              nframes_t nframes, nframes_t offset, bool with_processors, int declick,
-                              bool meter)
-{
-       /* There's no such thing as a MIDI bus for the time being.
-        * We'll do all the MIDI route work here for now, but the long-term goal is to have
-        * Route::process_output_buffers handle everything */
-       
-       if (meter && (_meter_point == MeterInput || _meter_point == MeterPreFader)) {
-               _meter->run_in_place(bufs, start_frame, end_frame, nframes, offset);
+MidiTrack::realtime_handle_transport_stopped ()
+{
+       Glib::RWLock::ReaderLock lm (_processor_lock, Glib::TRY_LOCK);
+       if (!lm.locked ()) {
+               return;
        }
 
-       // Run all processors
-       if (with_processors) {
-               Glib::RWLock::ReaderLock rm (_processor_lock, Glib::TRY_LOCK);
-               if (rm.locked()) {
-                       for (ProcessorList::iterator i = _processors.begin(); i != _processors.end(); ++i) {
-                               (*i)->run_in_place (bufs, start_frame, end_frame, nframes, offset);
-                       }
-               } 
-       }
-       
-       if (meter && (_meter_point == MeterPostFader)) {
-               _meter->run_in_place(bufs, start_frame, end_frame, nframes, offset);
+       for (ProcessorList::iterator i = _processors.begin(); i != _processors.end(); ++i) {
+               (*i)->realtime_handle_transport_stopped ();
        }
-       
-       // Main output stage
-       if (muted()) {
-               IO::silence(nframes, offset);
-       } else {
+}
 
-               // Write 'automation' controllers (e.g. CC events from a UI slider)
-               write_controller_messages(bufs.get_midi(0), start_frame, end_frame, nframes, offset);
-               
-               deliver_output(bufs, start_frame, end_frame, nframes, offset);
+void
+MidiTrack::push_midi_input_to_step_edit_ringbuffer (framecnt_t nframes)
+{
+       PortSet& ports (_input->ports());
+
+       for (PortSet::iterator p = ports.begin(DataType::MIDI); p != ports.end(DataType::MIDI); ++p) {
+
+               Buffer& b (p->get_buffer (nframes));
+               const MidiBuffer* const mb = dynamic_cast<MidiBuffer*>(&b);
+               assert (mb);
+
+               for (MidiBuffer::const_iterator e = mb->begin(); e != mb->end(); ++e) {
+
+                       const Evoral::MIDIEvent<framepos_t> ev(*e, false);
+
+                       /* note on, since for step edit, note length is determined
+                          elsewhere 
+                       */
+
+                       if (ev.is_note_on()) {
+                               /* we don't care about the time for this purpose */
+                               _step_edit_ring_buffer.write (0, ev.type(), ev.size(), ev.buffer());
+                       }
+               }
        }
 }
 
 void
-MidiTrack::write_controller_messages(MidiBuffer& output_buf, nframes_t start, nframes_t end, 
-                              nframes_t nframes, nframes_t offset)
+MidiTrack::write_out_of_band_data (BufferSet& bufs, framepos_t /*start*/, framepos_t /*end*/, framecnt_t nframes)
 {
-       // Append immediate events (UI controls)
-       _immediate_events.read(output_buf, 0, 0, offset + nframes - 1); // all stamps = 0
+       MidiBuffer& buf (bufs.get_midi (0));
+
+       // Append immediate events
+
+       if (_immediate_events.read_space()) {
+
+               DEBUG_TRACE (DEBUG::MidiIO, string_compose ("%1 has %2 of immediate events to deliver\n", 
+                                                           name(), _immediate_events.read_space()));
+
+               /* write as many of the immediate events as we can, but give "true" as
+                * the last argument ("stop on overflow in destination") so that we'll
+                * ship the rest out next time.
+                *
+                * the (nframes-1) argument puts all these events at the last
+                * possible position of the output buffer, so that we do not 
+                * violate monotonicity when writing.
+                */
+               
+               _immediate_events.read (buf, 0, 1, nframes-1, true);
+       }
+
+       // MIDI thru: send incoming data "through" output
+       if (_midi_thru && _session.transport_speed() != 0.0f && _input->n_ports().n_midi()) {
+               buf.merge_in_place (_input->midi(0)->get_midi_buffer(nframes));
+       }
 }
 
 int
-MidiTrack::export_stuff (BufferSet& bufs, nframes_t nframes, nframes_t end_frame)
+MidiTrack::export_stuff (BufferSet& /*bufs*/, framecnt_t /*nframes*/, framepos_t /*end_frame*/)
 {
        return -1;
 }
 
-void
-MidiTrack::set_latency_delay (nframes_t longest_session_latency)
-{
-       Route::set_latency_delay (longest_session_latency);
-       _diskstream->set_roll_delay (_roll_delay);
-}
-
 boost::shared_ptr<Region>
-MidiTrack::bounce (InterThreadInfo& itt)
+MidiTrack::bounce (InterThreadInfo& /*itt*/)
 {
        throw;
        // vector<MidiSource*> srcs;
@@ -618,7 +485,7 @@ MidiTrack::bounce (InterThreadInfo& itt)
 
 
 boost::shared_ptr<Region>
-MidiTrack::bounce_range (nframes_t start, nframes_t end, InterThreadInfo& itt)
+MidiTrack::bounce_range (framepos_t /*start*/, framepos_t /*end*/, InterThreadInfo& /*itt*/, bool /*enable_processing*/)
 {
        throw;
        //vector<MidiSource*> srcs;
@@ -627,7 +494,7 @@ MidiTrack::bounce_range (nframes_t start, nframes_t end, InterThreadInfo& itt)
 }
 
 void
-MidiTrack::freeze (InterThreadInfo& itt)
+MidiTrack::freeze_me (InterThreadInfo& /*itt*/)
 {
 }
 
@@ -646,8 +513,9 @@ MidiTrack::set_note_mode (NoteMode m)
 }
 
 void
-MidiTrack::midi_panic() 
+MidiTrack::midi_panic()
 {
+       DEBUG_TRACE (DEBUG::MidiIO, string_compose ("%1 delivers panic data\n", name()));
        for (uint8_t channel = 0; channel <= 0xF; channel++) {
                uint8_t ev[3] = { MIDI_CMD_CONTROL | channel, MIDI_CTL_SUSTAIN, 0 };
                write_immediate_event(3, ev);
@@ -672,7 +540,7 @@ MidiTrack::write_immediate_event(size_t size, const uint8_t* buf)
 }
 
 void
-MidiTrack::MidiControl::set_value(float val)
+MidiTrack::MidiControl::set_value(double val)
 {
        bool valid = false;
        if (isinf(val)) {
@@ -686,15 +554,14 @@ MidiTrack::MidiControl::set_value(float val)
        } else {
                valid = true;
        }
-       
+
        if (!valid) {
                return;
        }
 
        assert(val <= _list->parameter().max());
-       size_t size = 3;
-
        if ( ! automation_playback()) {
+               size_t size = 3;
                uint8_t ev[3] = { _list->parameter().channel(), int(val), 0 };
                switch(_list->parameter().type()) {
                case MidiCCAutomation:
@@ -702,25 +569,25 @@ MidiTrack::MidiControl::set_value(float val)
                        ev[1] = _list->parameter().id();
                        ev[2] = int(val);
                        break;
-                       
+
                case MidiPgmChangeAutomation:
                        size = 2;
                        ev[0] += MIDI_CMD_PGM_CHANGE;
                        ev[1] = int(val);
                        break;
-                       
+
                case MidiChannelPressureAutomation:
                        size = 2;
                        ev[0] += MIDI_CMD_CHANNEL_PRESSURE;
                        ev[1] = int(val);
                        break;
-                       
+
                case MidiPitchBenderAutomation:
                        ev[0] += MIDI_CMD_BENDER;
                        ev[1] = 0x7F & int(val);
                        ev[2] = 0x7F & (int(val) >> 7);
                        break;
-                       
+
                default:
                        assert(false);
                }
@@ -728,5 +595,71 @@ MidiTrack::MidiControl::set_value(float val)
        }
 
        AutomationControl::set_value(val);
-} 
+}
 
+void
+MidiTrack::set_step_editing (bool yn)
+{
+       if (_session.record_status() != Session::Disabled) {
+               return;
+       }
+
+       if (yn != _step_editing) {
+               _step_editing = yn;
+               StepEditStatusChange (yn);
+       }
+}
+
+void
+MidiTrack::set_midi_thru (bool yn)
+{
+       _midi_thru = yn;
+}
+
+boost::shared_ptr<SMFSource>
+MidiTrack::write_source (uint32_t)
+{
+       return midi_diskstream()->write_source ();
+}
+
+void
+MidiTrack::set_channel_mode (ChannelMode mode, uint16_t mask)
+{
+       midi_diskstream()->set_channel_mode (mode, mask);
+}
+
+ChannelMode
+MidiTrack::get_channel_mode ()
+{
+       return midi_diskstream()->get_channel_mode ();
+}
+
+uint16_t
+MidiTrack::get_channel_mask ()
+{
+       return midi_diskstream()->get_channel_mask ();
+}
+
+boost::shared_ptr<MidiPlaylist>
+MidiTrack::midi_playlist ()
+{
+       return midi_diskstream()->midi_playlist ();
+}
+
+void
+MidiTrack::diskstream_data_recorded (boost::shared_ptr<MidiBuffer> buf, boost::weak_ptr<MidiSource> src)
+{
+       DataRecorded (buf, src); /* EMIT SIGNAL */
+}
+                              
+bool
+MidiTrack::should_monitor () const
+{
+       return true;
+}
+
+bool
+MidiTrack::send_silence () const
+{
+       return false;
+}