libs/ardour/ticker.cc

   1 /*
   2     Copyright (C) 2008 Hans Baier
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18     $Id$
  19 */
  20
  21 #include "ardour/ticker.h"
  22 #include "ardour/session.h"
  23 #include "ardour/tempo.h"
  24
  25 #ifdef DEBUG_MIDI_CLOCK
  26 #include <iostream>
  27 using namespace std;
  28 #endif
  29
  30 namespace ARDOUR
  31 {
  32
  33
  34 void Ticker::set_session(Session& s)
  35 {
  36          _session = &s;
  37
  38          if (_session) {
  39                  _session->tick.connect(mem_fun (*this, &Ticker::tick));
  40                  _session->GoingAway.connect(mem_fun (*this, &Ticker::going_away));
  41          }
  42 }
  43
  44 void MidiClockTicker::set_session(Session& s)
  45 {
  46          Ticker::set_session(s);
  47
  48          if (_session) {
  49                  _session->MIDIClock_PortChanged.connect(
  50                                  mem_fun (*this, &MidiClockTicker::update_midi_clock_port));
  51                  _session->TransportStateChange.connect(
  52                                  mem_fun (*this, &MidiClockTicker::transport_state_changed));
  53                  _session->PositionChanged.connect(
  54                                  mem_fun (*this, &MidiClockTicker::position_changed));
  55                  _session->TransportLooped.connect(
  56                                  mem_fun (*this, &MidiClockTicker::transport_looped));
  57                  update_midi_clock_port();
  58          }
  59 }
  60
  61 void MidiClockTicker::update_midi_clock_port()
  62 {
  63          _midi_port = _session->midi_clock_port();
  64 }
  65
  66 void MidiClockTicker::transport_state_changed()
  67 {
  68         if (_session->exporting()) {
  69                 /* no midi clock during export, for now */
  70                 return;
  71         }
  72
  73         float     speed    = _session->transport_speed();
  74         nframes_t position = _session->transport_frame();
  75 #ifdef DEBUG_MIDI_CLOCK
  76         cerr << "Transport state change, speed:" << speed << "position:" << position<< " play loop " << _session->get_play_loop() << endl;
  77 #endif
  78         if (speed == 1.0f) {
  79                 _last_tick = position;
  80
  81                 if (!Config->get_send_midi_clock())
  82                         return;
  83
  84                 if (_session->get_play_loop()) {
  85                         assert(_session->locations()->auto_loop_location());
  86                         if (position == _session->locations()->auto_loop_location()->start()) {
  87                                 send_start_event(0);
  88                         } else {
  89                                 send_continue_event(0);
  90                         }
  91                 } else if (position == 0) {
  92                         send_start_event(0);
  93                 } else {
  94                         send_continue_event(0);
  95                 }
  96
  97                 send_midi_clock_event(0);
  98
  99         } else if (speed == 0.0f) {
 100                 if (!Config->get_send_midi_clock())
 101                         return;
 102
 103                 send_stop_event(0);
 104         }
 105
 106         tick(position, *((ARDOUR::BBT_Time *) 0), *((Timecode::Time *)0));
 107 }
 108
 109 void MidiClockTicker::position_changed(nframes_t position)
 110 {
 111 #ifdef DEBUG_MIDI_CLOCK
 112         cerr << "Position changed:" << position << endl;
 113 #endif
 114         _last_tick = position;
 115 }
 116
 117 void MidiClockTicker::transport_looped()
 118 {
 119         Location* loop_location = _session->locations()->auto_loop_location();
 120         assert(loop_location);
 121
 122 #ifdef DEBUG_MIDI_CLOCK
 123         cerr << "Transport looped, position:" <<  _session->transport_frame()
 124              << " loop start " << loop_location->start( )
 125              << " loop end " << loop_location->end( )
 126              << " play loop " << _session->get_play_loop()
 127              <<  endl;
 128 #endif
 129
 130         // adjust _last_tick, so that the next MIDI clock message is sent
 131         // in due time (and the tick interval is still constant)
 132         nframes_t elapsed_since_last_tick = loop_location->end() - _last_tick;
 133         _last_tick = loop_location->start() - elapsed_since_last_tick;
 134 }
 135
 136 void MidiClockTicker::tick(const nframes_t& transport_frames, const BBT_Time& /*transport_bbt*/, const Timecode::Time& /*transport_smpt*/)
 137 {
 138 #ifdef WITH_JACK_MIDI
 139         if (!Config->get_send_midi_clock() || _session == 0 || _session->transport_speed() != 1.0f)
 140                 return;
 141
 142         MIDI::JACK_MidiPort* jack_port = dynamic_cast<MIDI::JACK_MidiPort*>(_midi_port);
 143         assert(jack_port);
 144
 145         while (true) {
 146                 double next_tick = _last_tick + one_ppqn_in_frames(transport_frames);
 147                 nframes_t next_tick_offset = nframes_t(next_tick) - transport_frames;
 148
 149 #ifdef DEBUG_MIDI_CLOCK
 150                 cerr << "Transport:" << transport_frames
 151                          << ":Last tick time:" << _last_tick << ":"
 152                          << ":Next tick time:" << next_tick << ":"
 153                          << "Offset:" << next_tick_offset << ":"
 154                          << "cycle length:" << jack_port->nframes_this_cycle()
 155                          << endl;
 156 #endif
 157
 158                 if (next_tick_offset >= jack_port->nframes_this_cycle())
 159                         return;
 160
 161                 send_midi_clock_event(next_tick_offset);
 162
 163                 _last_tick = next_tick;
 164         }
 165 #endif // WITH_JACK_MIDI
 166 }
 167
 168 double MidiClockTicker::one_ppqn_in_frames(nframes_t transport_position)
 169 {
 170         const Tempo& current_tempo = _session->tempo_map().tempo_at(transport_position);
 171         const Meter& current_meter = _session->tempo_map().meter_at(transport_position);
 172         double frames_per_beat =
 173                 current_tempo.frames_per_beat(_session->nominal_frame_rate(),
 174                                               current_meter);
 175
 176         double quarter_notes_per_beat = 4.0 / current_tempo.note_type();
 177         double frames_per_quarter_note = frames_per_beat / quarter_notes_per_beat;
 178
 179         return frames_per_quarter_note / double (_ppqn);
 180 }
 181
 182 void MidiClockTicker::send_midi_clock_event(nframes_t offset)
 183 {
 184 #ifdef WITH_JACK_MIDI
 185         assert (MIDI::JACK_MidiPort::is_process_thread());
 186 #endif // WITH_JACK_MIDI
 187 #ifdef DEBUG_MIDI_CLOCK
 188         cerr << "Tick with offset " << offset << endl;
 189 #endif // DEBUG_MIDI_CLOCK
 190         static uint8_t _midi_clock_tick[1] = { MIDI_CMD_COMMON_CLOCK };
 191         _midi_port->write(_midi_clock_tick, 1, offset);
 192 }
 193
 194 void MidiClockTicker::send_start_event(nframes_t offset)
 195 {
 196         static uint8_t _midi_clock_tick[1] = { MIDI_CMD_COMMON_START };
 197         _midi_port->write(_midi_clock_tick, 1, offset);
 198 }
 199
 200 void MidiClockTicker::send_continue_event(nframes_t offset)
 201 {
 202         static uint8_t _midi_clock_tick[1] = { MIDI_CMD_COMMON_CONTINUE };
 203         _midi_port->write(_midi_clock_tick, 1, offset);
 204 }
 205
 206 void MidiClockTicker::send_stop_event(nframes_t offset)
 207 {
 208         static uint8_t _midi_clock_tick[1] = { MIDI_CMD_COMMON_STOP };
 209         _midi_port->write(_midi_clock_tick, 1, offset);
 210 }
 211
 212 }
 213