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 (2.0 / 60.0) // 1 BpM = 1 / 60 Hz
50 session = (ISlaveSessionProxy *) new SlaveSessionProxy(s);
55 MIDIClock_Slave::MIDIClock_Slave (ISlaveSessionProxy* session_proxy, int ppqn)
56 : session(session_proxy)
58 , bandwidth (2.0 / 60.0) // 1 BpM = 1 / 60 Hz
63 MIDIClock_Slave::~MIDIClock_Slave()
69 MIDIClock_Slave::rebind (MidiPort& port)
71 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("MIDIClock_Slave: connecting to port %1\n", port.name()));
73 port_connections.drop_connections ();
75 port.self_parser().timing.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::update_midi_clock, this, _1, _2));
76 port.self_parser().start.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::start, this, _1, _2));
77 port.self_parser().contineu.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::contineu, this, _1, _2));
78 port.self_parser().stop.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::stop, this, _1, _2));
79 port.self_parser().position.connect_same_thread (port_connections, boost::bind (&MIDIClock_Slave::position, this, _1, _2, 3));
84 MIDIClock_Slave::calculate_one_ppqn_in_frames_at(framepos_t time)
86 const Tempo& current_tempo = session->tempo_map().tempo_at(time);
87 double frames_per_beat = current_tempo.frames_per_beat(session->frame_rate());
89 double quarter_notes_per_beat = 4.0 / current_tempo.note_type();
90 double frames_per_quarter_note = frames_per_beat / quarter_notes_per_beat;
92 one_ppqn_in_frames = frames_per_quarter_note / double (ppqn);
93 // DEBUG_TRACE (DEBUG::MidiClock, string_compose ("at %1, one ppqn = %2\n", time, one_ppqn_in_frames));
97 MIDIClock_Slave::calculate_song_position(uint16_t song_position_in_sixteenth_notes)
99 framepos_t song_position_frames = 0;
100 for (uint16_t i = 1; i <= song_position_in_sixteenth_notes; ++i) {
101 // one quarter note contains ppqn pulses, so a sixteenth note is ppqn / 4 pulses
102 calculate_one_ppqn_in_frames_at(song_position_frames);
103 song_position_frames += one_ppqn_in_frames * (framepos_t)(ppqn / 4);
106 return song_position_frames;
110 MIDIClock_Slave::calculate_filter_coefficients()
112 // omega = 2 * PI * Bandwidth / MIDI clock frame frequency in Hz
113 omega = 2.0 * M_PI * bandwidth * one_ppqn_in_frames / session->frame_rate();
114 b = 1.4142135623730950488 * omega;
119 MIDIClock_Slave::update_midi_clock (Parser& /*parser*/, framepos_t timestamp)
121 // some pieces of hardware send MIDI Clock all the time
122 if ( (!_starting) && (!_started) ) {
126 pframes_t cycle_offset = timestamp - session->sample_time_at_cycle_start();
128 calculate_one_ppqn_in_frames_at(should_be_position);
130 framepos_t elapsed_since_start = timestamp - first_timestamp;
133 if (_starting || last_timestamp == 0) {
134 midi_clock_count = 0;
136 first_timestamp = timestamp;
137 elapsed_since_start = should_be_position;
139 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("first clock message after start received @ %1\n", timestamp));
141 // calculate filter coefficients
142 calculate_filter_coefficients();
145 e2 = double(one_ppqn_in_frames) / double(session->frame_rate());
146 t0 = double(elapsed_since_start) / double(session->frame_rate());
149 // let ardour go after first MIDI Clock Event
153 should_be_position += one_ppqn_in_frames;
154 calculate_filter_coefficients();
156 // calculate loop error
157 // we use session->transport_frame() instead of t1 here
158 // because t1 is used to calculate the transport speed,
159 // so the loop will compensate for accumulating rounding errors
160 error = (double(should_be_position) - (double(session->transport_frame()) + double(cycle_offset)));
161 e = error / double(session->frame_rate());
162 current_delta = error;
170 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("clock #%1 @ %2 should-be %3 transport %4 error %5 appspeed %6 "
171 "read-delta %7 should-be delta %8 t1-t0 %9 t0 %10 t1 %11 framerate %12 engine %13\n",
172 midi_clock_count, // #
173 elapsed_since_start, // @
174 should_be_position, // should-be
175 session->transport_frame(), // transport
177 ((t1 - t0) * session->frame_rate()) / one_ppqn_in_frames, // appspeed
178 timestamp - last_timestamp, // read delta
179 one_ppqn_in_frames, // should-be delta
180 (t1 - t0) * session->frame_rate(), // t1-t0
181 t0 * session->frame_rate(), // t0
182 t1 * session->frame_rate(), // t1
183 session->frame_rate(), // framerate
184 session->frame_time()
188 last_timestamp = timestamp;
192 MIDIClock_Slave::start (Parser& /*parser*/, framepos_t timestamp)
194 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("MIDIClock_Slave got start message at time %1 engine time %2 transport_frame %3\n", timestamp, session->frame_time(), session->transport_frame()));
202 should_be_position = session->transport_frame();
207 MIDIClock_Slave::reset ()
209 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("MidiClock_Slave reset(): calculated filter bandwidth is %1 for period size %2\n", bandwidth, session->frames_per_cycle()));
211 should_be_position = session->transport_frame();
217 // session->request_locate(0, false);
222 MIDIClock_Slave::contineu (Parser& /*parser*/, framepos_t /*timestamp*/)
224 DEBUG_TRACE (DEBUG::MidiClock, "MIDIClock_Slave got continue message\n");
234 MIDIClock_Slave::stop (Parser& /*parser*/, framepos_t /*timestamp*/)
236 DEBUG_TRACE (DEBUG::MidiClock, "MIDIClock_Slave got stop message\n");
238 if (_started || _starting) {
241 // locate to last MIDI clock position
242 session->request_transport_speed(0.0);
244 // we need to go back to the last MIDI beat (6 ppqn)
245 // and lets hope the tempo didnt change in the meantime :)
247 // begin at the should be position, because
248 // that is the position of the last MIDI Clock
249 // message and that is probably what the master
250 // expects where we are right now
251 framepos_t stop_position = should_be_position;
253 // find out the last MIDI beat: go back #midi_clocks mod 6
254 // and lets hope the tempo didnt change in those last 6 beats :)
255 stop_position -= (midi_clock_count % 6) * one_ppqn_in_frames;
257 session->request_locate(stop_position, false);
258 should_be_position = stop_position;
264 MIDIClock_Slave::position (Parser& /*parser*/, byte* message, size_t size)
266 // we are note supposed to get position messages while we are running
267 // so lets be robust and ignore those
268 if (_started || _starting) {
273 byte lsb = message[1];
274 byte msb = message[2];
275 assert((lsb <= 0x7f) && (msb <= 0x7f));
277 uint16_t position_in_sixteenth_notes = (uint16_t(msb) << 7) | uint16_t(lsb);
278 framepos_t position_in_frames = calculate_song_position(position_in_sixteenth_notes);
280 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("Song Position: %1 frames: %2\n", position_in_sixteenth_notes, position_in_frames));
282 session->request_locate(position_in_frames, false);
283 should_be_position = position_in_frames;
289 MIDIClock_Slave::locked () const
295 MIDIClock_Slave::ok() const
301 MIDIClock_Slave::starting() const
307 MIDIClock_Slave::stop_if_no_more_clock_events(framepos_t& pos, framepos_t now)
309 /* no timecode for 1/4 second ? conclude that its stopped */
310 if (last_timestamp &&
311 now > last_timestamp &&
312 now - last_timestamp > session->frame_rate() / 4) {
313 DEBUG_TRACE (DEBUG::MidiClock, "No MIDI Clock frames received for some time, stopping!\n");
314 pos = should_be_position;
315 session->request_transport_speed (0);
316 session->request_locate (should_be_position, false);
324 MIDIClock_Slave::speed_and_position (double& speed, framepos_t& pos)
326 if (!_started || _starting) {
328 pos = should_be_position;
332 framepos_t engine_now = session->frame_time();
334 if (stop_if_no_more_clock_events(pos, engine_now)) {
339 speed = ((t1 - t0) * session->frame_rate()) / one_ppqn_in_frames;
341 // provide a 0.1% deadzone to lock the speed
342 if (fabs(speed - 1.0) <= 0.001)
345 // calculate position
346 if (engine_now > last_timestamp) {
347 // we are in between MIDI clock messages
348 // so we interpolate position according to speed
349 framecnt_t elapsed = engine_now - last_timestamp;
350 pos = (framepos_t) (should_be_position + double(elapsed) * speed);
352 // A new MIDI clock message has arrived this cycle
353 pos = should_be_position;
356 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("speed_and_position: speed %1 should-be %2 transport %3 \n", speed, pos, session->transport_frame()));
362 MIDIClock_Slave::resolution() const
365 return (framecnt_t) one_ppqn_in_frames * ppqn;
369 MIDIClock_Slave::approximate_current_delta() const
372 if (last_timestamp == 0 || _starting) {
373 snprintf(delta, sizeof(delta), "\u2012\u2012\u2012\u2012");
375 snprintf(delta, sizeof(delta), "\u0394<span foreground=\"green\" face=\"monospace\" >%s%s%" PRIi64 "</span>sm",
376 LEADINGZERO(abs(current_delta)), PLUSMINUS(-current_delta), abs(current_delta));
378 return std::string(delta);