2 Copyright (C) 2002 Paul Davis
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 #ifndef __ardour_slave_h__
21 #define __ardour_slave_h__
25 #include <glibmm/threads.h>
29 #include "pbd/signals.h"
31 #include "timecode/time.h"
33 #include "ardour/libardour_visibility.h"
34 #include "ardour/types.h"
35 #include "midi++/parser.h"
36 #include "midi++/types.h"
39 /* used for approximate_current_delta(): */
40 #define PLUSMINUS(A) ( ((A)<0) ? "-" : (((A)>0) ? "+" : "\u00B1") )
41 #define LEADINGZERO(A) ( (A)<10 ? " " : (A)<100 ? " " : (A)<1000 ? " " : "" )
53 * @brief The Slave interface can be used to sync ARDOURs tempo to an external source
54 * like MTC, MIDI Clock, etc.
56 * The name of the interface may be a bit misleading: A subclass of Slave actually
57 * acts as a time master for ARDOUR, that means ARDOUR will try to follow the
58 * speed and transport position of the implementation of Slave.
59 * Therefore it is rather that class, that makes ARDOUR a slave by connecting it
60 * to its external time master.
62 class LIBARDOUR_API Slave {
68 * This is the most important function to implement:
69 * Each process cycle, Session::follow_slave will call this method.
70 * and after the method call they should
72 * Session::follow_slave will then try to follow the given
73 * <em>position</em> using a delay locked loop (DLL),
74 * starting with the first given transport speed.
75 * If the values of speed and position contradict each other,
76 * ARDOUR will always follow the position and disregard the speed.
77 * Although, a correct speed is important so that ARDOUR
78 * can sync to the master time source quickly.
80 * For background information on delay locked loops,
81 * see http://www.kokkinizita.net/papers/usingdll.pdf
83 * The method has the following precondition:
86 * Slave::ok() should return true, otherwise playback will stop
87 * immediately and the method will not be called
90 * when the references speed and position are passed into the Slave
91 * they are uninitialized
95 * After the method call the following postconditions should be met:
98 * The first position value on transport start should be 0,
99 * otherwise ARDOUR will try to locate to the new position
100 * rather than move to it
103 * the references speed and position should be assigned
104 * to the Slaves current requested transport speed
105 * and transport position.
108 * Slave::resolution() should be greater than the maximum distance of
109 * ARDOURs transport position to the slaves requested transport position.
111 * <li>Slave::locked() should return true, otherwise Session::no_roll will be called</li>
112 * <li>Slave::starting() should be false, otherwise the transport will not move until it becomes true</li> *
115 * @param speed - The transport speed requested
116 * @param position - The transport position requested
117 * @return - The return value is currently ignored (see Session::follow_slave)
119 virtual bool speed_and_position (double& speed, framepos_t& position) = 0;
122 * reports to ARDOUR whether the Slave is currently synced to its external
125 * @return - when returning false, the transport will stop rolling
127 virtual bool locked() const = 0;
130 * reports to ARDOUR whether the slave is in a sane state
132 * @return - when returning false, the transport will be stopped and the slave
133 * disconnected from ARDOUR.
135 virtual bool ok() const = 0;
138 * reports to ARDOUR whether the slave is in the process of starting
141 * @return - when returning false, transport will not move until this method returns true
143 virtual bool starting() const { return false; }
146 * @return - the timing resolution of the Slave - If the distance of ARDOURs transport
147 * to the slave becomes greater than the resolution, sound will stop
149 virtual framecnt_t resolution() const = 0;
152 * @return - when returning true, ARDOUR will wait for seekahead_distance() before transport
155 virtual bool requires_seekahead () const = 0;
158 * @return the number of frames that this slave wants to seek ahead. Relevant
159 * only if requires_seekahead() returns true.
162 virtual framecnt_t seekahead_distance() const { return 0; }
165 * @return - when returning true, ARDOUR will use transport speed 1.0 no matter what
168 virtual bool is_always_synced() const { return false; }
171 * @return - whether ARDOUR should use the slave speed without any adjustments
173 virtual bool give_slave_full_control_over_transport_speed() const { return false; }
176 * @return - current time-delta between engine and sync-source
178 virtual std::string approximate_current_delta() const { return ""; }
182 /// We need this wrapper for testability, it's just too hard to mock up a session class
183 class LIBARDOUR_API ISlaveSessionProxy {
185 virtual ~ISlaveSessionProxy() {}
186 virtual TempoMap& tempo_map() const { return *((TempoMap *) 0); }
187 virtual framecnt_t frame_rate() const { return 0; }
188 virtual pframes_t frames_per_cycle() const { return 0; }
189 virtual framepos_t audible_frame () const { return 0; }
190 virtual framepos_t transport_frame () const { return 0; }
191 virtual pframes_t frames_since_cycle_start () const { return 0; }
192 virtual framepos_t sample_time_at_cycle_start() const { return 0; }
193 virtual framepos_t frame_time () const { return 0; }
195 virtual void request_locate (framepos_t /*frame*/, bool with_roll = false) {
198 virtual void request_transport_speed (double /*speed*/) {}
202 /// The Session Proxy for use in real Ardour
203 class LIBARDOUR_API SlaveSessionProxy : public ISlaveSessionProxy {
207 SlaveSessionProxy(Session &s) : session(s) {}
209 TempoMap& tempo_map() const;
210 framecnt_t frame_rate() const;
211 pframes_t frames_per_cycle() const;
212 framepos_t audible_frame () const;
213 framepos_t transport_frame () const;
214 pframes_t frames_since_cycle_start () const;
215 framepos_t sample_time_at_cycle_start() const;
216 framepos_t frame_time () const;
218 void request_locate (framepos_t frame, bool with_roll = false);
219 void request_transport_speed (double speed);
222 struct LIBARDOUR_API SafeTime {
225 framepos_t timestamp;
238 class LIBARDOUR_API TimecodeSlave : public Slave {
242 virtual Timecode::TimecodeFormat apparent_timecode_format() const = 0;
244 /* this is intended to be used by a UI and polled from a timeout. it should
245 return a string describing the current position of the TC source. it
246 should NOT do any computation, but should use a cached value
247 of the TC source position.
249 virtual std::string approximate_current_position() const = 0;
251 framepos_t timecode_offset;
252 bool timecode_negative_offset;
255 class LIBARDOUR_API MTC_Slave : public TimecodeSlave {
257 MTC_Slave (Session&, MidiPort&);
260 void rebind (MidiPort&);
261 bool speed_and_position (double&, framepos_t&);
265 void handle_locate (const MIDI::byte*);
267 framecnt_t resolution () const;
268 bool requires_seekahead () const { return false; }
269 framecnt_t seekahead_distance() const;
270 bool give_slave_full_control_over_transport_speed() const;
272 Timecode::TimecodeFormat apparent_timecode_format() const;
273 std::string approximate_current_position() const;
274 std::string approximate_current_delta() const;
279 PBD::ScopedConnectionList port_connections;
280 PBD::ScopedConnection config_connection;
281 bool can_notify_on_unknown_rate;
283 static const int frame_tolerance;
286 framepos_t mtc_frame; /* current time */
287 double mtc_frame_dll;
288 framepos_t last_inbound_frame; /* when we got it; audio clocked */
289 MIDI::byte last_mtc_fps_byte;
290 framepos_t window_begin;
291 framepos_t window_end;
292 framepos_t first_mtc_timestamp;
293 bool did_reset_tc_format;
294 Timecode::TimecodeFormat saved_tc_format;
295 Glib::Threads::Mutex reset_lock;
296 uint32_t reset_pending;
298 int transport_direction;
302 double speedup_due_to_tc_mismatch;
303 double quarter_frame_duration;
304 Timecode::TimecodeFormat mtc_timecode;
305 Timecode::TimecodeFormat a3e_timecode;
306 Timecode::Time timecode;
307 bool printed_timecode_warning;
308 frameoffset_t current_delta;
310 /* DLL - chase MTC */
311 double t0; ///< time at the beginning of the MTC quater frame
312 double t1; ///< calculated end of the MTC quater frame
313 double e2; ///< second order loop error
314 double b, c, omega; ///< DLL filter coefficients
316 /* DLL - sync engine */
317 int engine_dll_initstate;
318 double te0; ///< time at the beginning of the engine process
319 double te1; ///< calculated sync time
320 double ee2; ///< second order loop error
321 double be, ce, oe; ///< DLL filter coefficients
323 void reset (bool with_pos);
324 void queue_reset (bool with_pos);
327 void update_mtc_qtr (MIDI::Parser&, int, framepos_t);
328 void update_mtc_time (const MIDI::byte *, bool, framepos_t);
329 void update_mtc_status (MIDI::MTC_Status);
330 void read_current (SafeTime *) const;
331 void reset_window (framepos_t);
332 bool outside_window (framepos_t) const;
333 void init_mtc_dll(framepos_t, double);
334 void init_engine_dll (framepos_t, framepos_t);
335 void parse_timecode_offset();
336 void parameter_changed(std::string const & p);
339 class LIBARDOUR_API LTC_Slave : public TimecodeSlave {
341 LTC_Slave (Session&);
344 bool speed_and_position (double&, framepos_t&);
349 framecnt_t resolution () const;
350 bool requires_seekahead () const { return false; }
351 framecnt_t seekahead_distance () const { return 0; }
352 bool give_slave_full_control_over_transport_speed() const { return true; }
354 Timecode::TimecodeFormat apparent_timecode_format() const;
355 std::string approximate_current_position() const;
356 std::string approximate_current_delta() const;
359 void parse_ltc(const pframes_t, const Sample* const, const framecnt_t);
360 void process_ltc(framepos_t const);
361 void init_engine_dll (framepos_t, int32_t);
362 bool detect_discontinuity(LTCFrameExt *, int, bool);
363 bool detect_ltc_fps(int, bool);
364 bool equal_ltc_frame_time(LTCFrame *a, LTCFrame *b);
367 void resync_latency();
368 void parse_timecode_offset();
369 void parameter_changed(std::string const & p);
372 bool did_reset_tc_format;
373 Timecode::TimecodeFormat saved_tc_format;
375 LTCDecoder * decoder;
376 double frames_per_ltc_frame;
377 Timecode::Time timecode;
378 LTCFrameExt prev_frame;
381 framecnt_t monotonic_cnt;
382 framecnt_t last_timestamp;
383 framecnt_t last_ltc_frame;
385 frameoffset_t current_delta;
388 int ltc_detect_fps_cnt;
389 int ltc_detect_fps_max;
390 bool printed_timecode_warning;
391 bool sync_lock_broken;
392 Timecode::TimecodeFormat ltc_timecode;
393 Timecode::TimecodeFormat a3e_timecode;
395 PBD::ScopedConnectionList port_connections;
396 PBD::ScopedConnection config_connection;
397 LatencyRange ltc_slave_latency;
399 /* DLL - chase LTC */
400 int transport_direction;
401 int engine_dll_initstate;
402 double t0; ///< time at the beginning of the MTC quater frame
403 double t1; ///< calculated end of the MTC quater frame
404 double e2; ///< second order loop error
405 double b, c; ///< DLL filter coefficients
408 class LIBARDOUR_API MIDIClock_Slave : public Slave {
410 MIDIClock_Slave (Session&, MidiPort&, int ppqn = 24);
412 /// Constructor for unit tests
413 MIDIClock_Slave (ISlaveSessionProxy* session_proxy = 0, int ppqn = 24);
416 void rebind (MidiPort&);
417 bool speed_and_position (double&, framepos_t&);
421 bool starting() const;
423 framecnt_t resolution () const;
424 bool requires_seekahead () const { return false; }
425 bool give_slave_full_control_over_transport_speed() const { return true; }
427 void set_bandwidth (double a_bandwith) { bandwidth = a_bandwith; }
428 std::string approximate_current_delta() const;
431 ISlaveSessionProxy* session;
432 PBD::ScopedConnectionList port_connections;
434 /// pulses per quarter note for one MIDI clock frame (default 24)
437 /// the duration of one ppqn in frame time
438 double one_ppqn_in_frames;
440 /// the timestamp of the first MIDI clock message
441 framepos_t first_timestamp;
443 /// the time stamp and should-be transport position of the last inbound MIDI clock message
444 framepos_t last_timestamp;
445 double should_be_position;
447 /// the number of midi clock messages received (zero-based)
449 long midi_clock_count;
451 //the delay locked loop (DLL), see www.kokkinizita.net/papers/usingdll.pdf
453 /// time at the beginning of the MIDI clock frame
456 /// calculated end of the MIDI clock frame
459 /// loop error = real value - expected value
462 /// second order loop error
465 /// DLL filter bandwidth
468 /// DLL filter coefficients
471 frameoffset_t current_delta;
474 void start (MIDI::Parser& parser, framepos_t timestamp);
475 void contineu (MIDI::Parser& parser, framepos_t timestamp);
476 void stop (MIDI::Parser& parser, framepos_t timestamp);
477 void position (MIDI::Parser& parser, MIDI::byte* message, size_t size);
478 // we can't use continue because it is a C++ keyword
479 void calculate_one_ppqn_in_frames_at(framepos_t time);
480 framepos_t calculate_song_position(uint16_t song_position_in_sixteenth_notes);
481 void calculate_filter_coefficients();
482 void update_midi_clock (MIDI::Parser& parser, framepos_t timestamp);
483 void read_current (SafeTime *) const;
484 bool stop_if_no_more_clock_events(framepos_t& pos, framepos_t now);
486 /// whether transport should be rolling
489 /// is true if the MIDI Start message has just been received until
490 /// the first MIDI Clock Event
494 class LIBARDOUR_API Engine_Slave : public Slave
497 Engine_Slave (AudioEngine&);
500 bool speed_and_position (double& speed, framepos_t& pos);
502 bool starting() const { return _starting; }
505 framecnt_t resolution () const { return 1; }
506 bool requires_seekahead () const { return false; }
507 bool is_always_synced() const { return true; }
516 #endif /* __ardour_slave_h__ */