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 "pbd/compose.h"
  22 #include "midi++/port.h"
  23 #include "midi++/manager.h"
  24 #include "evoral/midi_events.h"
  25 #include "ardour/ticker.h"
  26 #include "ardour/session.h"
  27 #include "ardour/tempo.h"
  28 #include "ardour/debug.h"
  29
  30 using namespace ARDOUR;
  31
  32 void Ticker::set_session (Session* s)
  33 {
  34         SessionHandlePtr::set_session (s);
  35
  36         if (_session) {
  37                 _session->tick.connect_same_thread (_session_connections, boost::bind (&Ticker::tick, this, _1, _2, _3));
  38         }
  39 }
  40
  41 void MidiClockTicker::set_session (Session* s)
  42 {
  43          Ticker::set_session (s);
  44
  45          if (_session) {
  46                  _session->TransportStateChange.connect_same_thread (_session_connections, boost::bind (&MidiClockTicker::transport_state_changed, this));
  47                  _session->PositionChanged.connect_same_thread (_session_connections, boost::bind (&MidiClockTicker::position_changed, this, _1));
  48                  _session->TransportLooped.connect_same_thread (_session_connections, boost::bind (&MidiClockTicker::transport_looped, this));
  49                  update_midi_clock_port();
  50          }
  51 }
  52
  53 void
  54 MidiClockTicker::session_going_away ()
  55 {
  56         SessionHandlePtr::session_going_away();
  57         _midi_port = 0;
  58 }
  59
  60 void MidiClockTicker::update_midi_clock_port()
  61 {
  62         _midi_port = MIDI::Manager::instance()->midi_clock_output_port();
  63 }
  64
  65 void MidiClockTicker::transport_state_changed()
  66 {
  67         if (_session->exporting()) {
  68                 /* no midi clock during export, for now */
  69                 return;
  70         }
  71
  72         float      speed    = _session->transport_speed();
  73         framepos_t position = _session->transport_frame();
  74
  75         DEBUG_TRACE (PBD::DEBUG::MidiClock,
  76                      string_compose ("Transport state change, speed: %1 position: %2 play loop: %3\n", speed, position, _session->get_play_loop())
  77                 );
  78
  79         if (speed == 1.0f) {
  80                 _last_tick = position;
  81
  82                 if (!Config->get_send_midi_clock())
  83                         return;
  84
  85                 if (_session->get_play_loop()) {
  86                         assert(_session->locations()->auto_loop_location());
  87                         if (position == _session->locations()->auto_loop_location()->start()) {
  88                                 send_start_event(0);
  89                         } else {
  90                                 send_continue_event(0);
  91                         }
  92                 } else if (position == 0) {
  93                         send_start_event(0);
  94                 } else {
  95                         send_continue_event(0);
  96                 }
  97
  98                 send_midi_clock_event(0);
  99
 100         } else if (speed == 0.0f) {
 101                 if (!Config->get_send_midi_clock())
 102                         return;
 103
 104                 send_stop_event(0);
 105         }
 106
 107         tick(position, *((Timecode::BBT_Time *) 0), *((Timecode::Time *)0));
 108 }
 109
 110 void MidiClockTicker::position_changed (framepos_t position)
 111 {
 112         DEBUG_TRACE (PBD::DEBUG::MidiClock, string_compose ("Position change: %1\n", position));
 113
 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         DEBUG_TRACE (PBD::DEBUG::MidiClock,
 123                      string_compose ("Transport looped, position: %1, loop start: %2, loop end: %3, play loop: %4\n",
 124                                      _session->transport_frame(), loop_location->start(), loop_location->end(), _session->get_play_loop())
 125                 );
 126
 127         // adjust _last_tick, so that the next MIDI clock message is sent
 128         // in due time (and the tick interval is still constant)
 129         framecnt_t elapsed_since_last_tick = loop_location->end() - _last_tick;
 130         _last_tick = loop_location->start() - elapsed_since_last_tick;
 131 }
 132
 133 void MidiClockTicker::tick (const framepos_t& transport_frames, const Timecode::BBT_Time& /*transport_bbt*/, const Timecode::Time& /*transport_smpt*/)
 134 {
 135         if (!Config->get_send_midi_clock() || _session == 0 || _session->transport_speed() != 1.0f || _midi_port == 0)
 136                 return;
 137
 138         while (true) {
 139                 double next_tick = _last_tick + one_ppqn_in_frames(transport_frames);
 140                 framecnt_t next_tick_offset = framecnt_t(next_tick) - transport_frames;
 141
 142                 DEBUG_TRACE (PBD::DEBUG::MidiClock,
 143                              string_compose ("Transport: %1, last tick time: %2, next tick time: %3, offset: %4, cycle length: %5\n",
 144                                              transport_frames, _last_tick, next_tick, next_tick_offset, _midi_port->nframes_this_cycle()
 145                                      )
 146                         );
 147
 148                 if (next_tick_offset >= _midi_port->nframes_this_cycle())
 149                         return;
 150
 151                 send_midi_clock_event(next_tick_offset);
 152
 153                 _last_tick = next_tick;
 154         }
 155 }
 156
 157 double MidiClockTicker::one_ppqn_in_frames (framepos_t transport_position)
 158 {
 159         const Tempo& current_tempo = _session->tempo_map().tempo_at(transport_position);
 160         const Meter& current_meter = _session->tempo_map().meter_at(transport_position);
 161         double frames_per_beat =
 162                 current_tempo.frames_per_beat(_session->nominal_frame_rate(),
 163                                               current_meter);
 164
 165         double quarter_notes_per_beat = 4.0 / current_tempo.note_type();
 166         double frames_per_quarter_note = frames_per_beat / quarter_notes_per_beat;
 167
 168         return frames_per_quarter_note / double (_ppqn);
 169 }
 170
 171 void MidiClockTicker::send_midi_clock_event (pframes_t offset)
 172 {
 173         if (!_midi_port) {
 174                 return;
 175         }
 176
 177         DEBUG_TRACE (PBD::DEBUG::MidiClock, string_compose ("Tick with offset %1\n", offset));
 178
 179         static uint8_t _midi_clock_tick[1] = { MIDI_CMD_COMMON_CLOCK };
 180         _midi_port->write (_midi_clock_tick, 1, offset);
 181 }
 182
 183 void MidiClockTicker::send_start_event (pframes_t offset)
 184 {
 185         if (!_midi_port) {
 186                 return;
 187         }
 188
 189         static uint8_t _midi_clock_tick[1] = { MIDI_CMD_COMMON_START };
 190         _midi_port->write (_midi_clock_tick, 1, offset);
 191 }
 192
 193 void MidiClockTicker::send_continue_event (pframes_t offset)
 194 {
 195         if (!_midi_port) {
 196                 return;
 197         }
 198
 199         static uint8_t _midi_clock_tick[1] = { MIDI_CMD_COMMON_CONTINUE };
 200         _midi_port->write (_midi_clock_tick, 1, offset);
 201 }
 202
 203 void MidiClockTicker::send_stop_event (pframes_t offset)
 204 {
 205         if (!_midi_port) {
 206                 return;
 207         }
 208
 209         static uint8_t _midi_clock_tick[1] = { MIDI_CMD_COMMON_STOP };
 210         _midi_port->write (_midi_clock_tick, 1, offset);
 211 }
 212
 213
 214