move ownership of LTC I/O ports to Session, and manage as IO objects
[ardour.git] / libs / ardour / midi_diskstream.cc
index 45b7e8f4de4af429cf2216fe2b2ac471af0874d3..64f02b0ad9c59a520c0d4c973c179d26f7ed4964 100644 (file)
 
 #include "pbd/error.h"
 #include "pbd/basename.h"
-#include <glibmm/thread.h>
+#include <glibmm/threads.h>
 #include "pbd/xml++.h"
 #include "pbd/memento_command.h"
 #include "pbd/enumwriter.h"
 #include "pbd/stateful_diff_command.h"
 #include "pbd/stacktrace.h"
 
-#include "ardour/ardour.h"
 #include "ardour/audioengine.h"
 #include "ardour/butler.h"
-#include "ardour/configuration.h"
-#include "ardour/cycle_timer.h"
 #include "ardour/debug.h"
 #include "ardour/io.h"
 #include "ardour/midi_diskstream.h"
+#include "ardour/midi_model.h"
 #include "ardour/midi_playlist.h"
 #include "ardour/midi_port.h"
 #include "ardour/midi_region.h"
 #include "ardour/playlist_factory.h"
 #include "ardour/region_factory.h"
-#include "ardour/send.h"
 #include "ardour/session.h"
+#include "ardour/session_playlists.h"
 #include "ardour/smf_source.h"
+#include "ardour/types.h"
 #include "ardour/utils.h"
-#include "ardour/session_playlists.h"
-#include "ardour/route.h"
 
 #include "midi++/types.h"
 
@@ -73,11 +70,10 @@ MidiDiskstream::MidiDiskstream (Session &sess, const string &name, Diskstream::F
        : Diskstream(sess, name, flag)
        , _playback_buf(0)
        , _capture_buf(0)
-       , _source_port(0)
-       , _last_flush_frame(0)
        , _note_mode(Sustained)
        , _frames_written_to_ringbuffer(0)
        , _frames_read_from_ringbuffer(0)
+       , _gui_feed_buffer(AudioEngine::instance()->raw_buffer_size (DataType::MIDI))
 {
        in_set_state = true;
 
@@ -94,11 +90,10 @@ MidiDiskstream::MidiDiskstream (Session& sess, const XMLNode& node)
        : Diskstream(sess, node)
        , _playback_buf(0)
        , _capture_buf(0)
-       , _source_port(0)
-       , _last_flush_frame(0)
        , _note_mode(Sustained)
        , _frames_written_to_ringbuffer(0)
        , _frames_read_from_ringbuffer(0)
+       , _gui_feed_buffer(AudioEngine::instance()->raw_buffer_size (DataType::MIDI))
 {
        in_set_state = true;
 
@@ -136,7 +131,7 @@ MidiDiskstream::init ()
 
 MidiDiskstream::~MidiDiskstream ()
 {
-       Glib::Mutex::Lock lm (state_lock);
+       Glib::Threads::Mutex::Lock lm (state_lock);
 }
 
 
@@ -154,7 +149,7 @@ void
 MidiDiskstream::non_realtime_input_change ()
 {
        {
-               Glib::Mutex::Lock lm (state_lock);
+               Glib::Threads::Mutex::Lock lm (state_lock);
 
                if (input_change_pending.type == IOChange::NoChange) {
                        return;
@@ -172,7 +167,7 @@ MidiDiskstream::non_realtime_input_change ()
                        }
 
                        if (ni == 0) {
-                               _source_port = 0;
+                               _source_port.reset ();
                        } else {
                                _source_port = _io->midi(0);
                        }
@@ -202,7 +197,9 @@ MidiDiskstream::non_realtime_input_change ()
                seek (_session.transport_frame());
        }
 
-       _last_flush_frame = _session.transport_frame();
+       if (_write_source) {
+               _write_source->set_last_write_end (_session.transport_frame());
+       }
 }
 
 int
@@ -251,7 +248,6 @@ MidiDiskstream::use_new_playlist ()
        if ((playlist = boost::dynamic_pointer_cast<MidiPlaylist> (PlaylistFactory::create (
                        DataType::MIDI, _session, newname, hidden()))) != 0) {
 
-               playlist->set_orig_diskstream_id (id());
                return use_playlist (playlist);
 
        } else {
@@ -279,7 +275,6 @@ MidiDiskstream::use_copy_playlist ()
        newname = Playlist::bump_name (_playlist->name(), _session);
 
        if ((playlist  = boost::dynamic_pointer_cast<MidiPlaylist>(PlaylistFactory::create (midi_playlist(), newname))) != 0) {
-               playlist->set_orig_diskstream_id (id());
                return use_playlist (playlist);
        } else {
                return -1;
@@ -291,6 +286,7 @@ MidiDiskstream::use_copy_playlist ()
 int
 MidiDiskstream::set_destructive (bool yn)
 {
+       yn = 0; // stop pedantic gcc complaints about unused parameter
        assert( ! destructive());
        assert( ! yn);
        return -1;
@@ -305,183 +301,14 @@ MidiDiskstream::set_note_mode (NoteMode m)
                _write_source->model()->set_note_mode(m);
 }
 
-#if 0
-static void
-trace_midi (ostream& o, MIDI::byte *msg, size_t len)
-{
-       using namespace MIDI;
-       eventType type;
-       const char trace_prefix = ':';
-
-       type = (eventType) (msg[0]&0xF0);
-
-       switch (type) {
-       case off:
-               o << trace_prefix
-                  << "Channel "
-                  << (msg[0]&0xF)+1
-                  << " NoteOff NoteNum "
-                  << (int) msg[1]
-                  << " Vel "
-                  << (int) msg[2]
-                  << endl;
-               break;
-
-       case on:
-               o << trace_prefix
-                  << "Channel "
-                  << (msg[0]&0xF)+1
-                  << " NoteOn NoteNum "
-                  << (int) msg[1]
-                  << " Vel "
-                  << (int) msg[2]
-                  << endl;
-               break;
-
-       case polypress:
-               o << trace_prefix
-                  << "Channel "
-                  << (msg[0]&0xF)+1
-                  << " PolyPressure"
-                  << (int) msg[1]
-                  << endl;
-               break;
-
-       case MIDI::controller:
-               o << trace_prefix
-                  << "Channel "
-                  << (msg[0]&0xF)+1
-                  << " Controller "
-                  << (int) msg[1]
-                  << " Value "
-                  << (int) msg[2]
-                  << endl;
-               break;
-
-       case program:
-               o << trace_prefix
-                  << "Channel "
-                  << (msg[0]&0xF)+1
-                  <<  " Program Change ProgNum "
-                  << (int) msg[1]
-                  << endl;
-               break;
-
-       case chanpress:
-               o << trace_prefix
-                  << "Channel "
-                  << (msg[0]&0xF)+1
-                  << " Channel Pressure "
-                  << (int) msg[1]
-                  << endl;
-               break;
-
-       case MIDI::pitchbend:
-               o << trace_prefix
-                  << "Channel "
-                  << (msg[0]&0xF)+1
-                  << " Pitch Bend "
-                  << ((msg[2]<<7)|msg[1])
-                  << endl;
-               break;
-
-       case MIDI::sysex:
-               if (len == 1) {
-                       switch (msg[0]) {
-                       case 0xf8:
-                               o << trace_prefix
-                                  << "Clock"
-                                  << endl;
-                               break;
-                       case 0xfa:
-                               o << trace_prefix
-                                  << "Start"
-                                  << endl;
-                               break;
-                       case 0xfb:
-                               o << trace_prefix
-                                  << "Continue"
-                                  << endl;
-                               break;
-                       case 0xfc:
-                               o << trace_prefix
-                                  << "Stop"
-                                  << endl;
-                               break;
-                       case 0xfe:
-                               o << trace_prefix
-                                  << "Active Sense"
-                                  << endl;
-                               break;
-                       case 0xff:
-                               o << trace_prefix
-                                  << "System Reset"
-                                  << endl;
-                               break;
-                       default:
-                               o << trace_prefix
-                                  << "System Exclusive (1 byte : " << hex << (int) *msg << dec << ')'
-                                  << endl;
-                               break;
-                       }
-               } else {
-                       o << trace_prefix
-                          << "System Exclusive (" << len << ") = [ " << hex;
-                       for (unsigned int i = 0; i < len; ++i) {
-                               o << (int) msg[i] << ' ';
-                       }
-                       o << dec << ']' << endl;
-
-               }
-               break;
-
-       case MIDI::song:
-               o << trace_prefix << "Song" << endl;
-               break;
-
-       case MIDI::tune:
-               o << trace_prefix << "Tune" << endl;
-               break;
-
-       case MIDI::eox:
-               o << trace_prefix << "End-of-System Exclusive" << endl;
-               break;
-
-       case MIDI::timing:
-               o << trace_prefix << "Timing" << endl;
-               break;
-
-       case MIDI::start:
-               o << trace_prefix << "Start" << endl;
-               break;
-
-       case MIDI::stop:
-               o << trace_prefix << "Stop" << endl;
-               break;
-
-       case MIDI::contineu:
-               o << trace_prefix << "Continue" << endl;
-               break;
-
-       case active:
-               o << trace_prefix << "Active Sense" << endl;
-               break;
-
-       default:
-               o << trace_prefix << "Unrecognized MIDI message" << endl;
-               break;
-       }
-}
-#endif
-
 int
-MidiDiskstream::process (framepos_t transport_frame, pframes_t nframes, bool can_record, bool rec_monitors_input, bool& need_butler)
+MidiDiskstream::process (framepos_t transport_frame, pframes_t nframes, framecnt_t& playback_distance)
 {
-       int       ret = -1;
        framecnt_t rec_offset = 0;
        framecnt_t rec_nframes = 0;
        bool      nominally_recording;
        bool      re = record_enabled ();
+       bool      can_record = _session.actively_recording ();
 
        playback_distance = 0;
 
@@ -493,11 +320,13 @@ MidiDiskstream::process (framepos_t transport_frame, pframes_t nframes, bool can
                return 0;
        }
 
-       if (_source_port == 0) {
+       boost::shared_ptr<MidiPort> sp = _source_port.lock ();
+
+       if (sp == 0) {
                return 1;
        }
 
-       Glib::Mutex::Lock sm (state_lock, Glib::TRY_LOCK);
+       Glib::Threads::Mutex::Lock sm (state_lock, Glib::Threads::TRY_LOCK);
 
        if (!sm.locked()) {
                return 1;
@@ -506,7 +335,7 @@ MidiDiskstream::process (framepos_t transport_frame, pframes_t nframes, bool can
        adjust_capture_position = 0;
 
        if (nominally_recording || (re && was_recording && _session.get_record_enabled() && _session.config.get_punch_in())) {
-               OverlapType ot = coverage (first_recordable_frame, last_recordable_frame, transport_frame, transport_frame + nframes);
+               Evoral::OverlapType ot = Evoral::coverage (first_recordable_frame, last_recordable_frame, transport_frame, transport_frame + nframes);
 
                calculate_record_range(ot, transport_frame, nframes, rec_nframes, rec_offset);
 
@@ -524,7 +353,7 @@ MidiDiskstream::process (framepos_t transport_frame, pframes_t nframes, bool can
        if (nominally_recording || rec_nframes) {
 
                // Pump entire port buffer into the ring buffer (FIXME: split cycles?)
-               MidiBuffer& buf = _source_port->get_midi_buffer(nframes);
+               MidiBuffer& buf = sp->get_midi_buffer(nframes);
                for (MidiBuffer::iterator i = buf.begin(); i != buf.end(); ++i) {
                        const Evoral::MIDIEvent<MidiBuffer::TimeType> ev(*i, false);
                        assert(ev.buffer());
@@ -547,23 +376,29 @@ MidiDiskstream::process (framepos_t transport_frame, pframes_t nframes, bool can
                }
 
                if (buf.size() != 0) {
-                       /* XXX this needs fixing - realtime new() call for
-                          every time we get MIDI data in a process callback!
-                       */
-
-                       /* Make a copy of this data and emit it for the GUI to see */
-                       boost::shared_ptr<MidiBuffer> copy (new MidiBuffer (buf.capacity ()));
-                       for (MidiBuffer::iterator i = buf.begin(); i != buf.end(); ++i) {
-                               copy->push_back ((*i).time() + transport_frame, (*i).size(), (*i).buffer());
+                       Glib::Threads::Mutex::Lock lm (_gui_feed_buffer_mutex, Glib::Threads::TRY_LOCK);
+
+                       if (lm.locked ()) {
+                               /* Copy this data into our GUI feed buffer and tell the GUI
+                                  that it can read it if it likes.
+                               */
+                               _gui_feed_buffer.clear ();
+                               
+                               for (MidiBuffer::iterator i = buf.begin(); i != buf.end(); ++i) {
+                                       /* This may fail if buf is larger than _gui_feed_buffer, but it's not really
+                                          the end of the world if it does.
+                                       */
+                                       _gui_feed_buffer.push_back ((*i).time() + transport_frame, (*i).size(), (*i).buffer());
+                               }
                        }
 
-                       DataRecorded (copy, _write_source); /* EMIT SIGNAL */
+                       DataRecorded (_write_source); /* EMIT SIGNAL */
                }
 
        } else {
 
                if (was_recording) {
-                       finish_capture (rec_monitors_input);
+                       finish_capture ();
                }
 
        }
@@ -594,17 +429,11 @@ MidiDiskstream::process (framepos_t transport_frame, pframes_t nframes, bool can
 
        }
 
-       ret = 0;
-
-       if (commit (nframes)) {
-               need_butler = true;
-       }
-
-       return ret;
+       return 0;
 }
 
 bool
-MidiDiskstream::commit (framecnt_t nframes)
+MidiDiskstream::commit (framecnt_t playback_distance)
 {
        bool need_butler = false;
 
@@ -621,13 +450,26 @@ MidiDiskstream::commit (framecnt_t nframes)
 
        uint32_t frames_read = g_atomic_int_get(&_frames_read_from_ringbuffer);
        uint32_t frames_written = g_atomic_int_get(&_frames_written_to_ringbuffer);
-       if ((frames_written - frames_read) + nframes < midi_readahead) {
-               need_butler = true;
+
+       /*
+         cerr << name() << " MDS written: " << frames_written << " - read: " << frames_read <<
+         " = " << frames_written - frames_read
+         << " + " << playback_distance << " < " << midi_readahead << " = " << need_butler << ")" << endl;
+       */
+
+       /* frames_read will generally be less than frames_written, but
+        * immediately after an overwrite, we can end up having read some data
+        * before we've written any. we don't need to trip an assert() on this,
+        * but we do need to check so that the decision on whether or not we
+        * need the butler is done correctly.
+        */
+       
+       if (frames_read <= frames_written) {
+               if ((frames_written - frames_read) + playback_distance < midi_readahead) {
+                       need_butler = true;
+               }
        }
 
-       /*cerr << "MDS written: " << frames_written << " - read: " << frames_read <<
-               " = " << frames_written - frames_read
-               << " + " << nframes << " < " << midi_readahead << " = " << need_butler << ")" << endl;*/
 
        return need_butler;
 }
@@ -661,9 +503,17 @@ MidiDiskstream::overwrite_existing_buffers ()
 int
 MidiDiskstream::seek (framepos_t frame, bool complete_refill)
 {
-       Glib::Mutex::Lock lm (state_lock);
+       Glib::Threads::Mutex::Lock lm (state_lock);
        int ret = -1;
 
+       if (g_atomic_int_get (&_frames_read_from_ringbuffer) == 0) {
+               /* we haven't read anything since the last seek,
+                  so flush all note trackers to prevent
+                  wierdness
+               */
+               reset_tracker ();
+       }
+
        _playback_buf->reset();
        _capture_buf->reset();
        g_atomic_int_set(&_frames_read_from_ringbuffer, 0);
@@ -735,16 +585,16 @@ MidiDiskstream::read (framepos_t& start, framecnt_t dur, bool reversed)
                        start = loop_start + ((start - loop_start) % loop_length);
                        //cerr << "to " << start << endl;
                }
-               //cerr << "start is " << start << "  loopstart: " << loop_start << "  loopend: " << loop_end << endl;
+               // cerr << "start is " << start << " end " << start+dur << "  loopstart: " << loop_start << "  loopend: " << loop_end << endl;
        }
 
        while (dur) {
 
                /* take any loop into account. we can't read past the end of the loop. */
 
-               if (loc && (loop_end - start < dur)) {
+               if (loc && (loop_end - start <= dur)) {
                        this_read = loop_end - start;
-                       //cerr << "reloop true: thisread: " << this_read << "  dur: " << dur << endl;
+                       // cerr << "reloop true: thisread: " << this_read << "  dur: " << dur << endl;
                        reloop = true;
                } else {
                        reloop = false;
@@ -760,13 +610,11 @@ MidiDiskstream::read (framepos_t& start, framecnt_t dur, bool reversed)
                if (midi_playlist()->read (*_playback_buf, start, this_read) != this_read) {
                        error << string_compose(
                                        _("MidiDiskstream %1: cannot read %2 from playlist at frame %3"),
-                                       _id, this_read, start) << endmsg;
+                                       id(), this_read, start) << endmsg;
                        return -1;
                }
 
-               g_atomic_int_add(&_frames_written_to_ringbuffer, this_read);
-
-               _read_data_count = _playlist->read_data_count();
+               g_atomic_int_add (&_frames_written_to_ringbuffer, this_read);
 
                if (reversed) {
 
@@ -860,20 +708,21 @@ MidiDiskstream::do_refill ()
 int
 MidiDiskstream::do_flush (RunContext /*context*/, bool force_flush)
 {
-       uint32_t to_write;
-       int32_t ret = 0;
+       framecnt_t to_write;
        framecnt_t total;
+       int32_t ret = 0;
 
-       _write_data_count = 0;
+       if (!_write_source) {
+               return 0;
+       }
 
-       total = _session.transport_frame() - _last_flush_frame;
+       assert (!destructive());
 
-       if (_last_flush_frame > _session.transport_frame() || _last_flush_frame < capture_start_frame) {
-               _last_flush_frame = _session.transport_frame();
-       }
+       total = _session.transport_frame() - _write_source->last_write_end();
 
-       if (total == 0 || _capture_buf->read_space() == 0
-                       || (!force_flush && (total < disk_io_chunk_frames && was_recording))) {
+       if (total == 0 || 
+           _capture_buf->read_space() == 0 || 
+           (!force_flush && (total < disk_io_chunk_frames) && was_recording)) {
                goto out;
        }
 
@@ -892,19 +741,18 @@ MidiDiskstream::do_flush (RunContext /*context*/, bool force_flush)
                ret = 1;
        }
 
-       to_write = disk_io_chunk_frames;
-
-       assert(!destructive());
+       if (force_flush) {
+               /* push out everything we have, right now */
+               to_write = max_framecnt;
+       } else {
+               to_write = disk_io_chunk_frames;
+       }
 
-       if (record_enabled() &&
-           ((_session.transport_frame() - _last_flush_frame > disk_io_chunk_frames) ||
-            force_flush)) {
-               if ((!_write_source) || _write_source->midi_write (*_capture_buf, get_capture_start_frame (0), to_write) != to_write) {
-                       error << string_compose(_("MidiDiskstream %1: cannot write to disk"), _id) << endmsg;
+       if (record_enabled() && ((total > disk_io_chunk_frames) || force_flush)) {
+               if (_write_source->midi_write (*_capture_buf, get_capture_start_frame (0), to_write) != to_write) {
+                       error << string_compose(_("MidiDiskstream %1: cannot write to disk"), id()) << endmsg;
                        return -1;
-               } else {
-                       _last_flush_frame = _session.transport_frame();
-               }
+               } 
        }
 
 out:
@@ -921,7 +769,7 @@ MidiDiskstream::transport_stopped_wallclock (struct tm& /*when*/, time_t /*twhen
        MidiRegion::SourceList::iterator src;
        vector<CaptureInfo*>::iterator ci;
 
-       finish_capture (true);
+       finish_capture ();
 
        /* butler is already stopped, but there may be work to do
           to flush remaining data to disk.
@@ -941,10 +789,10 @@ MidiDiskstream::transport_stopped_wallclock (struct tm& /*when*/, time_t /*twhen
        }
 
        /* XXX is there anything we can do if err != 0 ? */
-       Glib::Mutex::Lock lm (capture_info_lock);
+       Glib::Threads::Mutex::Lock lm (capture_info_lock);
 
        if (capture_info.empty()) {
-               return;
+               goto no_capture_stuff_to_do;
        }
 
        if (abort_capture) {
@@ -977,17 +825,17 @@ MidiDiskstream::transport_stopped_wallclock (struct tm& /*when*/, time_t /*twhen
                        _write_source->set_timeline_position (capture_info.front()->start);
                        _write_source->set_captured_for (_name);
 
+                       /* set length in beats to entire capture length */
+
+                       BeatsFramesConverter converter (_session.tempo_map(), capture_info.front()->start);
+                       const double total_capture_beats = converter.from (total_capture);
+                       _write_source->set_length_beats (total_capture_beats);
+
                        /* flush to disk: this step differs from the audio path,
                           where all the data is already on disk.
                        */
 
-                       _write_source->mark_streaming_write_completed ();
-
-                       /* set length in beats to entire capture length */
-
-                       BeatsFramesConverter converter (_session.tempo_map(), capture_info.front()->start);
-                       const double total_capture_beats = converter.from(total_capture);
-                       _write_source->set_length_beats(total_capture_beats);
+                       _write_source->mark_midi_streaming_write_completed (Evoral::Sequence<Evoral::MusicalTime>::ResolveStuckNotes, total_capture_beats);
 
                        /* we will want to be able to keep (over)writing the source
                           but we don't want it to be removable. this also differs
@@ -1097,12 +945,12 @@ MidiDiskstream::transport_stopped_wallclock (struct tm& /*when*/, time_t /*twhen
                delete *ci;
        }
 
-       if (_playlist) {
-               midi_playlist()->clear_note_trackers ();
-       }
-
        capture_info.clear ();
        capture_start_frame = 0;
+
+  no_capture_stuff_to_do:
+
+       reset_tracker ();
 }
 
 void
@@ -1122,7 +970,7 @@ MidiDiskstream::transport_looped (framepos_t transport_frame)
                        }
                }
 
-               finish_capture (true);
+               finish_capture ();
 
                // the next region will start recording via the normal mechanism
                // we'll set the start position to the current transport pos
@@ -1132,10 +980,14 @@ MidiDiskstream::transport_looped (framepos_t transport_frame)
                last_recordable_frame = max_framepos;
                was_recording = true;
        }
+
+       if (!Config->get_seamless_loop()) {
+               reset_tracker ();
+       }
 }
 
 void
-MidiDiskstream::finish_capture (bool /*rec_monitors_input*/)
+MidiDiskstream::finish_capture ()
 {
        was_recording = false;
 
@@ -1195,8 +1047,10 @@ MidiDiskstream::engage_record_enable ()
 
        g_atomic_int_set (&_record_enabled, 1);
 
-       if (_source_port && Config->get_monitoring_model() == HardwareMonitoring) {
-               _source_port->request_monitor_input (!(_session.config.get_auto_input() && rolling));
+       boost::shared_ptr<MidiPort> sp = _source_port.lock ();
+       
+       if (sp && Config->get_monitoring_model() == HardwareMonitoring) {
+               sp->request_jack_monitors_input (!(_session.config.get_auto_input() && rolling));
        }
 
        RecordEnableChanged (); /* EMIT SIGNAL */
@@ -1369,10 +1223,13 @@ MidiDiskstream::allocate_temporary_buffers ()
 }
 
 void
-MidiDiskstream::monitor_input (bool yn)
+MidiDiskstream::ensure_jack_monitors_input (bool yn)
 {
-       if (_source_port)
-               _source_port->ensure_monitor_input (yn);
+       boost::shared_ptr<MidiPort> sp = _source_port.lock ();
+       
+       if (sp) {
+               sp->ensure_jack_monitors_input (yn);
+       }
 }
 
 void
@@ -1393,15 +1250,25 @@ MidiDiskstream::set_align_style_from_io ()
 float
 MidiDiskstream::playback_buffer_load () const
 {
-       return (float) ((double) _playback_buf->read_space()/
-                       (double) _playback_buf->capacity());
+       /* For MIDI it's not trivial to differentiate the following two cases:
+          
+          1.  The playback buffer is empty because the system has run out of time to fill it.
+          2.  The playback buffer is empty because there is no more data on the playlist.
+
+          If we use a simple buffer load computation, we will report that the MIDI diskstream
+          cannot keep up when #2 happens, when in fact it can.  Since MIDI data rates
+          are so low compared to audio, just give a pretend answer here.
+       */
+       
+       return 1;
 }
 
 float
 MidiDiskstream::capture_buffer_load () const
 {
-       return (float) ((double) _capture_buf->write_space()/
-                       (double) _capture_buf->capacity());
+       /* We don't report playback buffer load, so don't report capture load either */
+       
+       return 1;
 }
 
 int
@@ -1410,43 +1277,41 @@ MidiDiskstream::use_pending_capture_data (XMLNode& /*node*/)
        return 0;
 }
 
-/** Writes playback events in the given range to \a dst, translating time stamps
- * so that an event at \a start has time = 0
+void
+MidiDiskstream::flush_playback (framepos_t start, framepos_t end)
+{
+       _playback_buf->flush (start, end);
+       g_atomic_int_add (&_frames_read_from_ringbuffer, end - start);
+}
+
+/** Writes playback events from playback_sample for nframes to dst, translating time stamps
+ *  so that an event at playback_sample has time = 0
  */
 void
-MidiDiskstream::get_playback (MidiBuffer& dst, framepos_t start, framepos_t end)
+MidiDiskstream::get_playback (MidiBuffer& dst, framecnt_t nframes)
 {
        dst.clear();
        assert(dst.size() == 0);
 
-       // Reverse.  ... We just don't do reverse, ok?  Back off.
-       if (end <= start) {
-               return;
-       }
-
-       // Translate stamps to be relative to start
-
-
 #ifndef NDEBUG
        DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose (
                             "%1 MDS pre-read read %4..%5 from %2 write to %3\n", _name,
-                            _playback_buf->get_read_ptr(), _playback_buf->get_write_ptr(), start, end));
+                            _playback_buf->get_read_ptr(), _playback_buf->get_write_ptr(), playback_sample, playback_sample + nframes));
 //        cerr << "================\n";
 //        _playback_buf->dump (cerr);
 //        cerr << "----------------\n";
 
-       const size_t events_read = _playback_buf->read(dst, start, end);
+       const size_t events_read = _playback_buf->read (dst, playback_sample, playback_sample + nframes);
        DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose (
                             "%1 MDS events read %2 range %3 .. %4 rspace %5 wspace %6 r@%7 w@%8\n",
-                            _name, events_read, start, end,
+                            _name, events_read, playback_sample, playback_sample + nframes,
                             _playback_buf->read_space(), _playback_buf->write_space(),
-                        _playback_buf->get_read_ptr(), _playback_buf->get_write_ptr()));
+                            _playback_buf->get_read_ptr(), _playback_buf->get_write_ptr()));
 #else
-       _playback_buf->read(dst, start, end);
+       _playback_buf->read (dst, playback_sample, playback_sample + nframes);
 #endif
 
-       gint32 frames_read = end - start;
-       g_atomic_int_add(&_frames_read_from_ringbuffer, frames_read);
+       g_atomic_int_add (&_frames_read_from_ringbuffer, nframes);
 }
 
 bool
@@ -1460,3 +1325,24 @@ MidiDiskstream::set_name (string const & name)
        return true;
 }
 
+boost::shared_ptr<MidiBuffer>
+MidiDiskstream::get_gui_feed_buffer () const
+{
+       boost::shared_ptr<MidiBuffer> b (new MidiBuffer (AudioEngine::instance()->raw_buffer_size (DataType::MIDI)));
+       
+       Glib::Threads::Mutex::Lock lm (_gui_feed_buffer_mutex);
+       b->copy (_gui_feed_buffer);
+       return b;
+}
+
+void
+MidiDiskstream::reset_tracker ()
+{
+       _playback_buf->reset_tracker ();
+
+       boost::shared_ptr<MidiPlaylist> mp (midi_playlist());
+
+       if (mp) {
+               mp->clear_note_trackers ();
+       }
+}