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.
23 #include <sys/types.h>
25 #include "pbd/error.h"
26 #include "pbd/failed_constructor.h"
27 #include "pbd/pthread_utils.h"
28 #include "pbd/convert.h"
30 #include "midi++/port.h"
32 #include "ardour/debug.h"
33 #include "ardour/slave.h"
34 #include "ardour/tempo.h"
39 using namespace ARDOUR;
43 MIDIClock_Slave::MIDIClock_Slave (Session& s, MIDI::Port& p, int ppqn)
45 , bandwidth (10.0 / 60.0) // 1 BpM = 1 / 60 Hz
47 session = (ISlaveSessionProxy *) new SlaveSessionProxy(s);
52 MIDIClock_Slave::MIDIClock_Slave (ISlaveSessionProxy* session_proxy, int ppqn)
53 : session(session_proxy)
55 , bandwidth (10.0 / 60.0) // 1 BpM = 1 / 60 Hz
60 MIDIClock_Slave::~MIDIClock_Slave()
66 MIDIClock_Slave::rebind (MIDI::Port& p)
68 port_connections.drop_connections();
72 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("MIDIClock_Slave: connecting to port %1\n", port->name()));
74 port->parser()->timing.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::update_midi_clock, this, _1, _2));
75 port->parser()->start.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::start, this, _1, _2));
76 port->parser()->contineu.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::contineu, this, _1, _2));
77 port->parser()->stop.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::stop, this, _1, _2));
78 port->parser()->position.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::position, this, _1, _2, 3));
82 MIDIClock_Slave::calculate_one_ppqn_in_frames_at(framepos_t time)
84 const Tempo& current_tempo = session->tempo_map().tempo_at(time);
85 double frames_per_beat = current_tempo.frames_per_beat(session->frame_rate());
87 double quarter_notes_per_beat = 4.0 / current_tempo.note_type();
88 double frames_per_quarter_note = frames_per_beat / quarter_notes_per_beat;
90 one_ppqn_in_frames = frames_per_quarter_note / double (ppqn);
91 // DEBUG_TRACE (DEBUG::MidiClock, string_compose ("at %1, one ppqn = %2\n", time, one_ppqn_in_frames));
95 MIDIClock_Slave::calculate_song_position(uint16_t song_position_in_sixteenth_notes)
97 framepos_t song_position_frames = 0;
98 for (uint16_t i = 1; i <= song_position_in_sixteenth_notes; ++i) {
99 // one quarter note contains ppqn pulses, so a sixteenth note is ppqn / 4 pulses
100 calculate_one_ppqn_in_frames_at(song_position_frames);
101 song_position_frames += one_ppqn_in_frames * (framepos_t)(ppqn / 4);
104 return song_position_frames;
108 MIDIClock_Slave::calculate_filter_coefficients()
110 // omega = 2 * PI * Bandwidth / MIDI clock frame frequency in Hz
111 omega = 2.0 * M_PI * bandwidth * one_ppqn_in_frames / session->frame_rate();
112 b = 1.4142135623730950488 * omega;
117 MIDIClock_Slave::update_midi_clock (Parser& /*parser*/, framepos_t timestamp)
119 // some pieces of hardware send MIDI Clock all the time
120 if ( (!_starting) && (!_started) ) {
124 calculate_one_ppqn_in_frames_at(should_be_position);
126 framepos_t elapsed_since_start = timestamp - first_timestamp;
129 if (_starting || last_timestamp == 0) {
130 midi_clock_count = 0;
132 first_timestamp = timestamp;
133 elapsed_since_start = should_be_position;
135 // calculate filter coefficients
136 calculate_filter_coefficients();
139 e2 = double(one_ppqn_in_frames) / double(session->frame_rate());
140 t0 = double(elapsed_since_start) / double(session->frame_rate());
143 // let ardour go after first MIDI Clock Event
147 should_be_position += one_ppqn_in_frames;
148 calculate_filter_coefficients();
150 // calculate loop error
151 // we use session->transport_frame() instead of t1 here
152 // because t1 is used to calculate the transport speed,
153 // so the loop will compensate for accumulating rounding errors
154 error = (double(should_be_position) - double(session->transport_frame()));
155 e = error / double(session->frame_rate());
156 current_delta = error;
164 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("clock #%1 @ %2 arrived %3 (theoretical) audible %4 transport %5 error %6 "
165 "read delta %7 should-be delta %8 t1-t0 %9 t0 %10 t1 %11 framerate %12 appspeed %13\n",
169 session->audible_frame(),
170 session->transport_frame(),
172 timestamp - last_timestamp,
174 (t1 -t0) * session->frame_rate(),
175 t0 * session->frame_rate(),
176 t1 * session->frame_rate(),
177 session->frame_rate(),
178 ((t1 - t0) * session->frame_rate()) / one_ppqn_in_frames));
180 last_timestamp = timestamp;
184 MIDIClock_Slave::start (Parser& /*parser*/, framepos_t timestamp)
186 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("MIDIClock_Slave got start message at time %1 engine time %2\n", timestamp, session->frame_time()));
194 should_be_position = session->transport_frame();
199 MIDIClock_Slave::reset ()
201 should_be_position = session->transport_frame();
207 // session->request_locate(0, false);
212 MIDIClock_Slave::contineu (Parser& /*parser*/, framepos_t /*timestamp*/)
214 DEBUG_TRACE (DEBUG::MidiClock, "MIDIClock_Slave got continue message\n");
224 MIDIClock_Slave::stop (Parser& /*parser*/, framepos_t /*timestamp*/)
226 DEBUG_TRACE (DEBUG::MidiClock, "MIDIClock_Slave got stop message\n");
228 if (_started || _starting) {
231 // locate to last MIDI clock position
232 session->request_transport_speed(0.0);
234 // we need to go back to the last MIDI beat (6 ppqn)
235 // and lets hope the tempo didnt change in the meantime :)
237 // begin at the should be position, because
238 // that is the position of the last MIDI Clock
239 // message and that is probably what the master
240 // expects where we are right now
241 framepos_t stop_position = should_be_position;
243 // find out the last MIDI beat: go back #midi_clocks mod 6
244 // and lets hope the tempo didnt change in those last 6 beats :)
245 stop_position -= (midi_clock_count % 6) * one_ppqn_in_frames;
247 session->request_locate(stop_position, false);
248 should_be_position = stop_position;
254 MIDIClock_Slave::position (Parser& /*parser*/, MIDI::byte* message, size_t size)
256 // we are note supposed to get position messages while we are running
257 // so lets be robust and ignore those
258 if (_started || _starting) {
263 MIDI::byte lsb = message[1];
264 MIDI::byte msb = message[2];
265 assert((lsb <= 0x7f) && (msb <= 0x7f));
267 uint16_t position_in_sixteenth_notes = (uint16_t(msb) << 7) | uint16_t(lsb);
268 framepos_t position_in_frames = calculate_song_position(position_in_sixteenth_notes);
270 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("Song Position: %1 frames: %2\n", position_in_sixteenth_notes, position_in_frames));
272 session->request_locate(position_in_frames, false);
273 should_be_position = position_in_frames;
279 MIDIClock_Slave::locked () const
285 MIDIClock_Slave::ok() const
291 MIDIClock_Slave::starting() const
297 MIDIClock_Slave::stop_if_no_more_clock_events(framepos_t& pos, framepos_t now)
299 /* no timecode for 1/4 second ? conclude that its stopped */
300 if (last_timestamp &&
301 now > last_timestamp &&
302 now - last_timestamp > session->frame_rate() / 4) {
303 DEBUG_TRACE (DEBUG::MidiClock, "No MIDI Clock frames received for some time, stopping!\n");
304 pos = should_be_position;
305 session->request_transport_speed (0);
306 session->request_locate (should_be_position, false);
314 MIDIClock_Slave::speed_and_position (double& speed, framepos_t& pos)
316 if (!_started || _starting) {
318 pos = should_be_position;
322 framepos_t engine_now = session->frame_time();
324 if (stop_if_no_more_clock_events(pos, engine_now)) {
329 speed = ((t1 - t0) * session->frame_rate()) / one_ppqn_in_frames;
331 // provide a 0.1% deadzone to lock the speed
332 if (fabs(speed - 1.0) <= 0.001)
335 // calculate position
336 if (engine_now > last_timestamp) {
337 // we are in between MIDI clock messages
338 // so we interpolate position according to speed
339 framecnt_t elapsed = engine_now - last_timestamp;
340 pos = (framepos_t) (should_be_position + double(elapsed) * speed);
342 // A new MIDI clock message has arrived this cycle
343 pos = should_be_position;
346 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("speed_and_position: %1 & %2 <-> %3 (transport)\n", speed, pos, session->transport_frame()));
352 MIDIClock_Slave::resolution() const
355 return (framecnt_t) one_ppqn_in_frames * ppqn;
359 MIDIClock_Slave::approximate_current_delta() const
362 if (last_timestamp == 0 || _starting) {
363 snprintf(delta, sizeof(delta), "\u2012\u2012\u2012\u2012");
365 snprintf(delta, sizeof(delta), "\u0394<span foreground=\"green\" face=\"monospace\" >%s%s%" PRIi64 "</span>sm",
366 LEADINGZERO(abs(current_delta)), PLUSMINUS(-current_delta), abs(current_delta));
368 return std::string(delta);