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"
29 #include "pbd/convert.h"
31 #include "midi++/port.h"
33 #include "ardour/debug.h"
34 #include "ardour/midi_buffer.h"
35 #include "ardour/midi_port.h"
36 #include "ardour/slave.h"
37 #include "ardour/tempo.h"
42 using namespace ARDOUR;
46 MIDIClock_Slave::MIDIClock_Slave (Session& s, MidiPort& p, int ppqn)
48 , bandwidth (10.0 / 60.0) // 1 BpM = 1 / 60 Hz
50 session = (ISlaveSessionProxy *) new SlaveSessionProxy(s);
54 parser.timing.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::update_midi_clock, this, _1, _2));
55 parser.start.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::start, this, _1, _2));
56 parser.contineu.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::contineu, this, _1, _2));
57 parser.stop.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::stop, this, _1, _2));
58 parser.position.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::position, this, _1, _2, 3));
62 MIDIClock_Slave::MIDIClock_Slave (ISlaveSessionProxy* session_proxy, int ppqn)
63 : session(session_proxy)
65 , bandwidth (10.0 / 60.0) // 1 BpM = 1 / 60 Hz
70 MIDIClock_Slave::~MIDIClock_Slave()
76 MIDIClock_Slave::process (pframes_t nframes)
78 MidiBuffer& mb (port->get_midi_buffer (nframes));
80 /* dump incoming MIDI to parser */
82 for (MidiBuffer::iterator b = mb.begin(); b != mb.end(); ++b) {
83 uint8_t* buf = (*b).buffer();
85 parser.set_timestamp ((*b).time());
87 uint32_t limit = (*b).size();
89 for (size_t n = 0; n < limit; ++n) {
90 parser.scanner (buf[n]);
98 MIDIClock_Slave::rebind (MidiPort& p)
101 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("MIDIClock_Slave: connecting to port %1\n", port->name()));
105 MIDIClock_Slave::calculate_one_ppqn_in_frames_at(framepos_t time)
107 const Tempo& current_tempo = session->tempo_map().tempo_at(time);
108 double frames_per_beat = current_tempo.frames_per_beat(session->frame_rate());
110 double quarter_notes_per_beat = 4.0 / current_tempo.note_type();
111 double frames_per_quarter_note = frames_per_beat / quarter_notes_per_beat;
113 one_ppqn_in_frames = frames_per_quarter_note / double (ppqn);
114 // DEBUG_TRACE (DEBUG::MidiClock, string_compose ("at %1, one ppqn = %2\n", time, one_ppqn_in_frames));
118 MIDIClock_Slave::calculate_song_position(uint16_t song_position_in_sixteenth_notes)
120 framepos_t song_position_frames = 0;
121 for (uint16_t i = 1; i <= song_position_in_sixteenth_notes; ++i) {
122 // one quarter note contains ppqn pulses, so a sixteenth note is ppqn / 4 pulses
123 calculate_one_ppqn_in_frames_at(song_position_frames);
124 song_position_frames += one_ppqn_in_frames * (framepos_t)(ppqn / 4);
127 return song_position_frames;
131 MIDIClock_Slave::calculate_filter_coefficients()
133 // omega = 2 * PI * Bandwidth / MIDI clock frame frequency in Hz
134 omega = 2.0 * M_PI * bandwidth * one_ppqn_in_frames / session->frame_rate();
135 b = 1.4142135623730950488 * omega;
140 MIDIClock_Slave::update_midi_clock (Parser& /*parser*/, framepos_t timestamp)
142 // some pieces of hardware send MIDI Clock all the time
143 if ( (!_starting) && (!_started) ) {
147 calculate_one_ppqn_in_frames_at(should_be_position);
149 framepos_t elapsed_since_start = timestamp - first_timestamp;
152 if (_starting || last_timestamp == 0) {
153 midi_clock_count = 0;
155 first_timestamp = timestamp;
156 elapsed_since_start = should_be_position;
158 // calculate filter coefficients
159 calculate_filter_coefficients();
162 e2 = double(one_ppqn_in_frames) / double(session->frame_rate());
163 t0 = double(elapsed_since_start) / double(session->frame_rate());
166 // let ardour go after first MIDI Clock Event
170 should_be_position += one_ppqn_in_frames;
171 calculate_filter_coefficients();
173 // calculate loop error
174 // we use session->transport_frame() instead of t1 here
175 // because t1 is used to calculate the transport speed,
176 // so the loop will compensate for accumulating rounding errors
177 error = (double(should_be_position) - double(session->transport_frame()));
178 e = error / double(session->frame_rate());
179 current_delta = error;
187 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("clock #%1 @ %2 arrived %3 (theoretical) audible %4 transport %5 error %6 "
188 "read delta %7 should-be delta %8 t1-t0 %9 t0 %10 t1 %11 framerate %12 appspeed %13\n",
192 session->audible_frame(),
193 session->transport_frame(),
195 timestamp - last_timestamp,
197 (t1 -t0) * session->frame_rate(),
198 t0 * session->frame_rate(),
199 t1 * session->frame_rate(),
200 session->frame_rate(),
201 ((t1 - t0) * session->frame_rate()) / one_ppqn_in_frames));
203 last_timestamp = timestamp;
207 MIDIClock_Slave::start (Parser& /*parser*/, framepos_t timestamp)
209 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("MIDIClock_Slave got start message at time %1 engine time %2\n", timestamp, session->frame_time()));
217 should_be_position = session->transport_frame();
222 MIDIClock_Slave::reset ()
224 should_be_position = session->transport_frame();
230 // session->request_locate(0, false);
235 MIDIClock_Slave::contineu (Parser& /*parser*/, framepos_t /*timestamp*/)
237 DEBUG_TRACE (DEBUG::MidiClock, "MIDIClock_Slave got continue message\n");
247 MIDIClock_Slave::stop (Parser& /*parser*/, framepos_t /*timestamp*/)
249 DEBUG_TRACE (DEBUG::MidiClock, "MIDIClock_Slave got stop message\n");
251 if (_started || _starting) {
254 // locate to last MIDI clock position
255 session->request_transport_speed(0.0);
257 // we need to go back to the last MIDI beat (6 ppqn)
258 // and lets hope the tempo didnt change in the meantime :)
260 // begin at the should be position, because
261 // that is the position of the last MIDI Clock
262 // message and that is probably what the master
263 // expects where we are right now
264 framepos_t stop_position = should_be_position;
266 // find out the last MIDI beat: go back #midi_clocks mod 6
267 // and lets hope the tempo didnt change in those last 6 beats :)
268 stop_position -= (midi_clock_count % 6) * one_ppqn_in_frames;
270 session->request_locate(stop_position, false);
271 should_be_position = stop_position;
277 MIDIClock_Slave::position (Parser& /*parser*/, byte* message, size_t size)
279 // we are note supposed to get position messages while we are running
280 // so lets be robust and ignore those
281 if (_started || _starting) {
286 byte lsb = message[1];
287 byte msb = message[2];
288 assert((lsb <= 0x7f) && (msb <= 0x7f));
290 uint16_t position_in_sixteenth_notes = (uint16_t(msb) << 7) | uint16_t(lsb);
291 framepos_t position_in_frames = calculate_song_position(position_in_sixteenth_notes);
293 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("Song Position: %1 frames: %2\n", position_in_sixteenth_notes, position_in_frames));
295 session->request_locate(position_in_frames, false);
296 should_be_position = position_in_frames;
302 MIDIClock_Slave::locked () const
308 MIDIClock_Slave::ok() const
314 MIDIClock_Slave::starting() const
320 MIDIClock_Slave::stop_if_no_more_clock_events(framepos_t& pos, framepos_t now)
322 /* no timecode for 1/4 second ? conclude that its stopped */
323 if (last_timestamp &&
324 now > last_timestamp &&
325 now - last_timestamp > session->frame_rate() / 4) {
326 DEBUG_TRACE (DEBUG::MidiClock, "No MIDI Clock frames received for some time, stopping!\n");
327 pos = should_be_position;
328 session->request_transport_speed (0);
329 session->request_locate (should_be_position, false);
337 MIDIClock_Slave::speed_and_position (double& speed, framepos_t& pos)
339 if (!_started || _starting) {
341 pos = should_be_position;
345 framepos_t engine_now = session->frame_time();
347 if (stop_if_no_more_clock_events(pos, engine_now)) {
352 speed = ((t1 - t0) * session->frame_rate()) / one_ppqn_in_frames;
354 // provide a 0.1% deadzone to lock the speed
355 if (fabs(speed - 1.0) <= 0.001)
358 // calculate position
359 if (engine_now > last_timestamp) {
360 // we are in between MIDI clock messages
361 // so we interpolate position according to speed
362 framecnt_t elapsed = engine_now - last_timestamp;
363 pos = (framepos_t) (should_be_position + double(elapsed) * speed);
365 // A new MIDI clock message has arrived this cycle
366 pos = should_be_position;
369 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("speed_and_position: %1 & %2 <-> %3 (transport)\n", speed, pos, session->transport_frame()));
375 MIDIClock_Slave::resolution() const
378 return (framecnt_t) one_ppqn_in_frames * ppqn;
382 MIDIClock_Slave::approximate_current_delta() const
385 if (last_timestamp == 0 || _starting) {
386 snprintf(delta, sizeof(delta), "\u2012\u2012\u2012\u2012");
388 snprintf(delta, sizeof(delta), "\u0394<span foreground=\"green\" face=\"monospace\" >%s%s%" PRIi64 "</span>sm",
389 LEADINGZERO(abs(current_delta)), PLUSMINUS(-current_delta), abs(current_delta));
391 return std::string(delta);