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/audioengine.h"
33 #include "ardour/debug.h"
34 #include "ardour/midi_buffer.h"
35 #include "ardour/midi_port.h"
36 #include "ardour/session.h"
37 #include "ardour/tempo.h"
38 #include "ardour/transport_master.h"
43 using namespace ARDOUR;
47 #define ENGINE AudioEngine::instance()
49 MIDIClock_TransportMaster::MIDIClock_TransportMaster (std::string const & name, int ppqn)
50 : TransportMaster (MIDIClock, name)
53 , should_be_position (0)
54 , midi_clock_count (0)
59 if ((_port = create_midi_port (string_compose ("%1 in", name))) == 0) {
60 throw failed_constructor();
64 MIDIClock_TransportMaster::~MIDIClock_TransportMaster()
66 port_connections.drop_connections ();
70 MIDIClock_TransportMaster::init ()
77 MIDIClock_TransportMaster::set_session (Session *session)
79 port_connections.drop_connections();
82 /* only connect to signals if we have a proxy, because otherwise we
83 * cannot interpet incoming data (no tempo map etc.)
87 parser.timing.connect_same_thread (port_connections, boost::bind (&MIDIClock_TransportMaster::update_midi_clock, this, _1, _2));
88 parser.start.connect_same_thread (port_connections, boost::bind (&MIDIClock_TransportMaster::start, this, _1, _2));
89 parser.contineu.connect_same_thread (port_connections, boost::bind (&MIDIClock_TransportMaster::contineu, this, _1, _2));
90 parser.stop.connect_same_thread (port_connections, boost::bind (&MIDIClock_TransportMaster::stop, this, _1, _2));
91 parser.position.connect_same_thread (port_connections, boost::bind (&MIDIClock_TransportMaster::position, this, _1, _2, 3));
98 MIDIClock_TransportMaster::speed_and_position (double& speed, samplepos_t& pos, samplepos_t now)
100 if (!_running || !_collect) {
104 if (fabs (_speed - 1.0) < 0.001) {
110 pos = should_be_position;
111 pos += (now - last_timestamp) * _speed;
117 MIDIClock_TransportMaster::pre_process (MIDI::pframes_t nframes, samplepos_t now, boost::optional<samplepos_t> session_pos)
119 /* Read and parse incoming MIDI */
121 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("preprocess with lt = %1 @ %2, running ? %3\n", last_timestamp, now, _running));
123 _midi_port->read_and_parse_entire_midi_buffer_with_no_speed_adjustment (nframes, parser, now);
125 /* no clock messages ever, or no clock messages for 1/4 second ? conclude that its stopped */
127 if (!last_timestamp || (now > last_timestamp && ((now - last_timestamp) > (ENGINE->sample_rate() / 4)))) {
133 midi_clock_count = 0;
135 DEBUG_TRACE (DEBUG::MidiClock, "No MIDI Clock messages received for some time, stopping!\n");
139 if (!_running && midi_clock_count == 0 && session_pos) {
140 should_be_position = *session_pos;
141 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("set sbp to %1\n", should_be_position));
145 const samplepos_t current_pos = should_be_position + ((now - last_timestamp) * _speed);
146 _current_delta = current_pos - *session_pos;
151 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("speed_and_position: speed %1 should-be %2 transport %3 \n", _speed, should_be_position, _session->transport_sample()));
155 MIDIClock_TransportMaster::calculate_one_ppqn_in_samples_at(samplepos_t time)
157 const double samples_per_quarter_note = _session->tempo_map().samples_per_quarter_note_at (time, ENGINE->sample_rate());
159 one_ppqn_in_samples = samples_per_quarter_note / double (ppqn);
160 // DEBUG_TRACE (DEBUG::MidiClock, string_compose ("at %1, one ppqn = %2\n", time, one_ppqn_in_samples));
164 MIDIClock_TransportMaster::calculate_song_position(uint16_t song_position_in_sixteenth_notes)
166 samplepos_t song_position_samples = 0;
167 for (uint16_t i = 1; i <= song_position_in_sixteenth_notes; ++i) {
168 // one quarter note contains ppqn pulses, so a sixteenth note is ppqn / 4 pulses
169 calculate_one_ppqn_in_samples_at(song_position_samples);
170 song_position_samples += one_ppqn_in_samples * (samplepos_t)(ppqn / 4);
173 return song_position_samples;
177 MIDIClock_TransportMaster::calculate_filter_coefficients (double qpm)
179 /* Paul says: I don't understand this computation of bandwidth
182 const double bandwidth = 2.0 / qpm;
184 /* Frequency of the clock messages is ENGINE->sample_rate() / * one_ppqn_in_samples, per second or in Hz */
185 const double freq = (double) ENGINE->sample_rate() / one_ppqn_in_samples;
187 const double omega = 2.0 * M_PI * bandwidth / freq;
188 b = 1.4142135623730950488 * omega; // sqrt (2.0) * omega
191 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("DLL coefficients: bw:%1 omega:%2 b:%3 c:%4\n", bandwidth, omega, b, c));
195 MIDIClock_TransportMaster::update_midi_clock (Parser& /*parser*/, samplepos_t timestamp)
197 samplepos_t elapsed_since_start = timestamp - first_timestamp;
200 calculate_one_ppqn_in_samples_at (should_be_position);
202 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("clock count %1, sbp %2\n", midi_clock_count, should_be_position));
204 if (midi_clock_count == 0) {
205 /* second 0xf8 message after start/reset has arrived */
207 first_timestamp = timestamp;
208 last_timestamp = timestamp;
210 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("first clock message after start received @ %1\n", timestamp));
214 should_be_position += one_ppqn_in_samples;
216 } else if (midi_clock_count == 1) {
218 /* second 0xf8 message has arrived. we can now estimate QPM
219 * (quarters per minute, and fully initialize the DLL
222 e = timestamp - last_timestamp;
224 const samplecnt_t samples_per_quarter = e * 24;
225 _bpm = (ENGINE->sample_rate() * 60.0) / samples_per_quarter;
227 calculate_filter_coefficients (_bpm);
229 /* finish DLL initialization */
233 t1 = t0 + e2; /* timestamp we predict for the next 0xf8 clock message */
236 should_be_position += one_ppqn_in_samples;
240 /* 3rd or later MIDI clock message. We can now compute actual
241 * speed (and tempo) with the DLL
244 e = timestamp - t1; // error between actual time of arrival of clock message and our predicted time
249 const double samples_per_quarter = (timestamp - last_timestamp) * 24.0;
250 const double instantaneous_bpm = (ENGINE->sample_rate() * 60.0) / samples_per_quarter;
251 const double lpf_coeff = 0.05;
253 const double predicted_clock_interval_in_samples = (t1 - t0);
255 /* _speed is relative to session tempo map */
257 _speed = predicted_clock_interval_in_samples / one_ppqn_in_samples;
259 /* _bpm (really, _qpm) is absolute */
261 /* detect substantial changes in apparent tempo (defined as a
262 * change of more than 20% of the current tempo.
265 if (fabs (instantaneous_bpm - _bpm) > (0.20 * _bpm)) {
266 _bpm = instantaneous_bpm;
268 _bpm += lpf_coeff * (instantaneous_bpm - _bpm);
271 calculate_filter_coefficients (_bpm);
273 // need at least two clock events to compute speed
276 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("start mclock running with speed = %1\n", (t1 - t0) / one_ppqn_in_samples));
281 should_be_position += one_ppqn_in_samples;
284 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("clock #%1 @ %2 should-be %3 transport %4 error %5 appspeed %6 "
285 "read-delta %7 should-be delta %8 t1-t0 %9 t0 %10 t1 %11 framerate %12 engine %13 running %14\n",
286 midi_clock_count, // #
287 elapsed_since_start, // @
288 should_be_position, // should-be
289 _session->transport_sample(), // transport
291 (t1 - t0) / one_ppqn_in_samples, // appspeed
292 timestamp - last_timestamp, // read delta
293 one_ppqn_in_samples, // should-be delta
297 ENGINE->sample_rate(), // framerate
298 ENGINE->sample_time(),
303 last_timestamp = timestamp;
307 MIDIClock_TransportMaster::start (Parser& /*parser*/, samplepos_t timestamp)
309 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("MIDIClock_TransportMaster got start message at time %1 engine time %2 transport_sample %3\n", timestamp, ENGINE->sample_time(), _session->transport_sample()));
314 should_be_position = _session->transport_sample();
319 MIDIClock_TransportMaster::reset ()
321 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("MidiClock Master reset(): calculated filter for period size %2\n", ENGINE->samples_per_cycle()));
323 should_be_position = _session->transport_sample();
332 MIDIClock_TransportMaster::contineu (Parser& /*parser*/, samplepos_t /*timestamp*/)
334 DEBUG_TRACE (DEBUG::MidiClock, "MIDIClock_TransportMaster got continue message\n");
340 MIDIClock_TransportMaster::stop (Parser& /*parser*/, samplepos_t /*timestamp*/)
342 DEBUG_TRACE (DEBUG::MidiClock, "MIDIClock_TransportMaster got stop message\n");
349 // we need to go back to the last MIDI beat (6 ppqn)
350 // and lets hope the tempo didnt change in the meantime :)
352 // begin at the should be position, because
353 // that is the position of the last MIDI Clock
354 // message and that is probably what the master
355 // expects where we are right now
357 // find out the last MIDI beat: go back #midi_clocks mod 6
358 // and lets hope the tempo didnt change in those last 6 beats :)
359 should_be_position -= (midi_clock_count % 6) * one_ppqn_in_samples;
364 MIDIClock_TransportMaster::position (Parser& /*parser*/, MIDI::byte* message, size_t size)
366 // we are not supposed to get position messages while we are running
367 // so lets be robust and ignore those
373 MIDI::byte lsb = message[1];
374 MIDI::byte msb = message[2];
375 assert((lsb <= 0x7f) && (msb <= 0x7f));
377 uint16_t position_in_sixteenth_notes = (uint16_t(msb) << 7) | uint16_t(lsb);
378 samplepos_t position_in_samples = calculate_song_position(position_in_sixteenth_notes);
380 DEBUG_TRACE (DEBUG::MidiClock, string_compose ("Song Position: %1 samples: %2\n", position_in_sixteenth_notes, position_in_samples));
382 should_be_position = position_in_samples;
388 MIDIClock_TransportMaster::locked () const
394 MIDIClock_TransportMaster::ok() const
400 MIDIClock_TransportMaster::starting() const
406 MIDIClock_TransportMaster::resolution() const
409 return (samplecnt_t) one_ppqn_in_samples * ppqn;
413 MIDIClock_TransportMaster::position_string () const
415 return std::string();
419 MIDIClock_TransportMaster::delta_string() const
422 if (last_timestamp == 0 || starting()) {
423 snprintf(delta, sizeof(delta), "\u2012\u2012\u2012\u2012");
425 snprintf(delta, sizeof(delta), "\u0394<span foreground=\"green\" face=\"monospace\" >%s%s%" PRIi64 "</span>sm",
426 LEADINGZERO(abs(_current_delta)), PLUSMINUS(-_current_delta), abs(_current_delta));
428 return std::string(delta);