2 Copyright (C) 2008 Paul Davis
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include <sys/types.h>
26 #include "pbd/error.h"
27 #include "pbd/failed_constructor.h"
28 #include "pbd/pthread_utils.h"
30 #include "midi++/port.h"
32 #include "ardour/debug.h"
33 #include "ardour/slave.h"
34 #include "ardour/session.h"
35 #include "ardour/audioengine.h"
36 #include "ardour/cycles.h"
37 #include "ardour/tempo.h"
43 using namespace ARDOUR;
47 MIDIClock_Slave::MIDIClock_Slave (Session& s, MIDI::Port& p, int ppqn)
49 , bandwidth (1.0 / 60.0) // 1 BpM = 1 / 60 Hz
51 session = (ISlaveSessionProxy *) new SlaveSessionProxy(s);
56 MIDIClock_Slave::MIDIClock_Slave (ISlaveSessionProxy* session_proxy, int ppqn)
57 : session(session_proxy)
59 , bandwidth (1.0 / 60.0) // 1 BpM = 1 / 60 Hz
64 MIDIClock_Slave::~MIDIClock_Slave()
70 MIDIClock_Slave::rebind (MIDI::Port& p)
72 port_connections.drop_connections();
76 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("MIDIClock_Slave: connecting to port %1\n", port->name()));
78 port->parser()->timing.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::update_midi_clock, this, _1, _2));
79 port->parser()->start.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::start, this, _1, _2));
80 port->parser()->contineu.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::contineu, this, _1, _2));
81 port->parser()->stop.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::stop, this, _1, _2));
82 port->parser()->position.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::position, this, _1, _2, 3));
86 MIDIClock_Slave::calculate_one_ppqn_in_frames_at(framepos_t time)
88 const Tempo& current_tempo = session->tempo_map().tempo_at(time);
89 const Meter& current_meter = session->tempo_map().meter_at(time);
90 double frames_per_beat =
91 current_tempo.frames_per_beat(session->frame_rate(),
94 double quarter_notes_per_beat = 4.0 / current_tempo.note_type();
95 double frames_per_quarter_note = frames_per_beat / quarter_notes_per_beat;
97 one_ppqn_in_frames = frames_per_quarter_note / double (ppqn);
98 // DEBUG_TRACE (DEBUG::MidiClock, string_compose ("at %1, one ppqn = %2\n", time, one_ppqn_in_frames));
102 MIDIClock_Slave::calculate_song_position(uint16_t song_position_in_sixteenth_notes)
104 framepos_t song_position_frames = 0;
105 for (uint16_t i = 1; i <= song_position_in_sixteenth_notes; ++i) {
106 // one quarter note contains ppqn pulses, so a sixteenth note is ppqn / 4 pulses
107 calculate_one_ppqn_in_frames_at(song_position_frames);
108 song_position_frames += one_ppqn_in_frames * (framepos_t)(ppqn / 4);
111 return song_position_frames;
115 MIDIClock_Slave::calculate_filter_coefficients()
117 // omega = 2 * PI * Bandwidth / MIDI clock frame frequency in Hz
118 omega = 2.0 * M_PI * bandwidth * one_ppqn_in_frames / session->frame_rate();
119 b = 1.4142135623730950488 * omega;
124 MIDIClock_Slave::update_midi_clock (Parser& /*parser*/, framepos_t timestamp)
126 // some pieces of hardware send MIDI Clock all the time
127 if ( (!_starting) && (!_started) ) {
131 calculate_one_ppqn_in_frames_at(should_be_position);
133 framepos_t elapsed_since_start = timestamp - first_timestamp;
136 if (_starting || last_timestamp == 0) {
137 midi_clock_count = 0;
139 first_timestamp = timestamp;
140 elapsed_since_start = should_be_position;
142 // calculate filter coefficients
143 calculate_filter_coefficients();
146 e2 = double(one_ppqn_in_frames) / double(session->frame_rate());
147 t0 = double(elapsed_since_start) / double(session->frame_rate());
150 // let ardour go after first MIDI Clock Event
154 should_be_position += one_ppqn_in_frames;
155 calculate_filter_coefficients();
157 // calculate loop error
158 // we use session->audible_frame() instead of t1 here
159 // because t1 is used to calculate the transport speed,
160 // so the loop will compensate for accumulating rounding errors
161 error = (double(should_be_position) - double(session->audible_frame()));
162 e = error / double(session->frame_rate());
170 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("clock #%1 @ %2 arrived %3 (theoretical) audible %4 transport %5 error %6 "
171 "read delta %7 should-be delta %8 t1-t0 %9 t0 %10 t1 %11 framerate %12 appspeed %13\n",
175 session->audible_frame(),
176 session->transport_frame(),
178 timestamp - last_timestamp,
180 (t1 -t0) * session->frame_rate(),
181 t0 * session->frame_rate(),
182 t1 * session->frame_rate(),
183 session->frame_rate(),
184 ((t1 - t0) * session->frame_rate()) / one_ppqn_in_frames));
186 last_timestamp = timestamp;
190 MIDIClock_Slave::start (Parser& /*parser*/, framepos_t timestamp)
192 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("MIDIClock_Slave got start message at time %1 engine time %2\n", timestamp, session->frame_time()));
200 should_be_position = session->transport_frame();
205 MIDIClock_Slave::reset ()
207 should_be_position = session->transport_frame();
213 // session->request_locate(0, false);
217 MIDIClock_Slave::contineu (Parser& /*parser*/, framepos_t /*timestamp*/)
219 DEBUG_TRACE (DEBUG::MidiClock, "MIDIClock_Slave got continue message\n");
229 MIDIClock_Slave::stop (Parser& /*parser*/, framepos_t /*timestamp*/)
231 DEBUG_TRACE (DEBUG::MidiClock, "MIDIClock_Slave got stop message\n");
233 if (_started || _starting) {
236 // locate to last MIDI clock position
237 session->request_transport_speed(0.0);
239 // we need to go back to the last MIDI beat (6 ppqn)
240 // and lets hope the tempo didnt change in the meantime :)
242 // begin at the should be position, because
243 // that is the position of the last MIDI Clock
244 // message and that is probably what the master
245 // expects where we are right now
246 framepos_t stop_position = should_be_position;
248 // find out the last MIDI beat: go back #midi_clocks mod 6
249 // and lets hope the tempo didnt change in those last 6 beats :)
250 stop_position -= (midi_clock_count % 6) * one_ppqn_in_frames;
252 session->request_locate(stop_position, false);
253 should_be_position = stop_position;
259 MIDIClock_Slave::position (Parser& /*parser*/, byte* message, size_t size)
261 // we are note supposed to get position messages while we are running
262 // so lets be robust and ignore those
263 if (_started || _starting) {
268 byte lsb = message[1];
269 byte msb = message[2];
270 assert((lsb <= 0x7f) && (msb <= 0x7f));
272 uint16_t position_in_sixteenth_notes = (uint16_t(msb) << 7) | uint16_t(lsb);
273 framepos_t position_in_frames = calculate_song_position(position_in_sixteenth_notes);
275 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("Song Position: %1 frames: %2\n", position_in_sixteenth_notes, position_in_frames));
277 session->request_locate(position_in_frames, false);
278 should_be_position = position_in_frames;
284 MIDIClock_Slave::locked () const
290 MIDIClock_Slave::ok() const
296 MIDIClock_Slave::starting() const
302 MIDIClock_Slave::stop_if_no_more_clock_events(framepos_t& pos, framepos_t now)
304 /* no timecode for 1/4 second ? conclude that its stopped */
305 if (last_timestamp &&
306 now > last_timestamp &&
307 now - last_timestamp > session->frame_rate() / 4) {
308 DEBUG_TRACE (DEBUG::MidiClock, "No MIDI Clock frames received for some time, stopping!\n");
309 pos = should_be_position;
310 session->request_transport_speed (0);
311 session->request_locate (should_be_position, false);
319 MIDIClock_Slave::speed_and_position (double& speed, framepos_t& pos)
321 if (!_started || _starting) {
323 pos = should_be_position;
327 framepos_t engine_now = session->frame_time();
329 if (stop_if_no_more_clock_events(pos, engine_now)) {
334 speed = ((t1 - t0) * session->frame_rate()) / one_ppqn_in_frames;
336 // provide a 3% deadzone to lock the speed
337 if (fabs(speed - 1.0) <= 0.03)
340 // calculate position
341 if (engine_now > last_timestamp) {
342 // we are in between MIDI clock messages
343 // so we interpolate position according to speed
344 framecnt_t elapsed = engine_now - last_timestamp;
345 pos = (framepos_t) (should_be_position + double(elapsed) * speed);
347 // A new MIDI clock message has arrived this cycle
348 pos = should_be_position;
351 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("speed_and_position: %1 & %2 <-> %3 (transport)\n", speed, pos, session->transport_frame()));
357 MIDIClock_Slave::resolution() const
360 return (framecnt_t) one_ppqn_in_frames * ppqn;