2 Copyright (C) 2008 Hans Baier
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.
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.
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.
21 #include "ardour/ticker.h"
22 #include "ardour/session.h"
23 #include "ardour/tempo.h"
29 void Ticker::set_session(Session& s)
34 _session->tick.connect(mem_fun (*this, &Ticker::tick));
35 _session->GoingAway.connect(mem_fun (*this, &Ticker::going_away));
39 void MidiClockTicker::set_session(Session& s)
41 Ticker::set_session(s);
44 _session->MIDIClock_PortChanged.connect(mem_fun (*this, &MidiClockTicker::update_midi_clock_port));
45 update_midi_clock_port();
49 void MidiClockTicker::update_midi_clock_port()
51 _jack_port = (MIDI::JACK_MidiPort*) _session->midi_clock_port();
54 void MidiClockTicker::tick(const nframes_t& transport_frames, const BBT_Time& transport_bbt, const SMPTE::Time& transport_smpt)
56 if (!Config->get_send_midi_clock() || _session == 0 || _session->transport_speed() != 1.0f)
59 const Tempo& current_tempo = _session->tempo_map().tempo_at(transport_frames);
60 const Meter& current_meter = _session->tempo_map().meter_at(transport_frames);
61 double frames_per_beat =
62 current_tempo.frames_per_beat(_session->nominal_frame_rate(),
65 double quarter_notes_per_beat = 4.0 / current_tempo.note_type();
66 double frames_per_quarter_note = frames_per_beat / quarter_notes_per_beat;
68 nframes_t one_ppqn_in_frames = frames_per_quarter_note / double (_ppqn);
70 nframes_t next_tick = _last_tick + one_ppqn_in_frames;
71 nframes_t next_tick_offset = next_tick - transport_frames;
73 assert(_jack_port->is_process_thread());
74 static uint8_t _midi_clock_tick[1] = { MIDI_CMD_COMMON_TICK };
75 _jack_port->write(_midi_clock_tick, 1, next_tick_offset);
77 _last_tick = next_tick;