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>
27 #include <jack/jack.h>
30 #include "pbd/signals.h"
32 #include "timecode/time.h"
34 #include "ardour/libardour_visibility.h"
35 #include "ardour/types.h"
36 #include "midi++/parser.h"
37 #include "midi++/types.h"
40 /* used for approximate_current_delta(): */
41 #define PLUSMINUS(A) ( ((A)<0) ? "-" : (((A)>0) ? "+" : "\u00B1") )
42 #define LEADINGZERO(A) ( (A)<10 ? " " : (A)<100 ? " " : (A)<1000 ? " " : "" )
54 * @brief The Slave interface can be used to sync ARDOURs tempo to an external source
55 * like MTC, MIDI Clock, etc.
57 * The name of the interface may be a bit misleading: A subclass of Slave actually
58 * acts as a time master for ARDOUR, that means ARDOUR will try to follow the
59 * speed and transport position of the implementation of Slave.
60 * Therefore it is rather that class, that makes ARDOUR a slave by connecting it
61 * to its external time master.
63 class LIBARDOUR_API Slave {
69 * This is the most important function to implement:
70 * Each process cycle, Session::follow_slave will call this method.
71 * and after the method call they should
73 * Session::follow_slave will then try to follow the given
74 * <em>position</em> using a delay locked loop (DLL),
75 * starting with the first given transport speed.
76 * If the values of speed and position contradict each other,
77 * ARDOUR will always follow the position and disregard the speed.
78 * Although, a correct speed is important so that ARDOUR
79 * can sync to the master time source quickly.
81 * For background information on delay locked loops,
82 * see http://www.kokkinizita.net/papers/usingdll.pdf
84 * The method has the following precondition:
87 * Slave::ok() should return true, otherwise playback will stop
88 * immediately and the method will not be called
91 * when the references speed and position are passed into the Slave
92 * they are uninitialized
96 * After the method call the following postconditions should be met:
99 * The first position value on transport start should be 0,
100 * otherwise ARDOUR will try to locate to the new position
101 * rather than move to it
104 * the references speed and position should be assigned
105 * to the Slaves current requested transport speed
106 * and transport position.
109 * Slave::resolution() should be greater than the maximum distance of
110 * ARDOURs transport position to the slaves requested transport position.
112 * <li>Slave::locked() should return true, otherwise Session::no_roll will be called</li>
113 * <li>Slave::starting() should be false, otherwise the transport will not move until it becomes true</li> *
116 * @param speed - The transport speed requested
117 * @param position - The transport position requested
118 * @return - The return value is currently ignored (see Session::follow_slave)
120 virtual bool speed_and_position (double& speed, framepos_t& position) = 0;
123 * reports to ARDOUR whether the Slave is currently synced to its external
126 * @return - when returning false, the transport will stop rolling
128 virtual bool locked() const = 0;
131 * reports to ARDOUR whether the slave is in a sane state
133 * @return - when returning false, the transport will be stopped and the slave
134 * disconnected from ARDOUR.
136 virtual bool ok() const = 0;
139 * reports to ARDOUR whether the slave is in the process of starting
142 * @return - when returning false, transport will not move until this method returns true
144 virtual bool starting() const { return false; }
147 * @return - the timing resolution of the Slave - If the distance of ARDOURs transport
148 * to the slave becomes greater than the resolution, sound will stop
150 virtual framecnt_t resolution() const = 0;
153 * @return - when returning true, ARDOUR will wait for seekahead_distance() before transport
156 virtual bool requires_seekahead () const = 0;
159 * @return the number of frames that this slave wants to seek ahead. Relevant
160 * only if requires_seekahead() returns true.
163 virtual framecnt_t seekahead_distance() const { return 0; }
166 * @return - when returning true, ARDOUR will use transport speed 1.0 no matter what
169 virtual bool is_always_synced() const { return false; }
172 * @return - whether ARDOUR should use the slave speed without any adjustments
174 virtual bool give_slave_full_control_over_transport_speed() const { return false; }
177 * @return - current time-delta between engine and sync-source
179 virtual std::string approximate_current_delta() const { return ""; }
183 /// We need this wrapper for testability, it's just too hard to mock up a session class
184 class LIBARDOUR_API ISlaveSessionProxy {
186 virtual ~ISlaveSessionProxy() {}
187 virtual TempoMap& tempo_map() const { return *((TempoMap *) 0); }
188 virtual framecnt_t frame_rate() const { return 0; }
189 virtual pframes_t frames_per_cycle() const { return 0; }
190 virtual framepos_t audible_frame () const { return 0; }
191 virtual framepos_t transport_frame () const { return 0; }
192 virtual pframes_t frames_since_cycle_start () const { return 0; }
193 virtual pframes_t sample_time_at_cycle_start() const { return 0; }
194 virtual framepos_t frame_time () const { return 0; }
196 virtual void request_locate (framepos_t /*frame*/, bool with_roll = false) {
199 virtual void request_transport_speed (double /*speed*/) {}
203 /// The Session Proxy for use in real Ardour
204 class LIBARDOUR_API SlaveSessionProxy : public ISlaveSessionProxy {
208 SlaveSessionProxy(Session &s) : session(s) {}
210 TempoMap& tempo_map() const;
211 framecnt_t frame_rate() const;
212 pframes_t frames_per_cycle() const;
213 framepos_t audible_frame () const;
214 framepos_t transport_frame () const;
215 pframes_t frames_since_cycle_start () const;
216 pframes_t sample_time_at_cycle_start() const;
217 framepos_t frame_time () const;
219 void request_locate (framepos_t frame, bool with_roll = false);
220 void request_transport_speed (double speed);
223 struct LIBARDOUR_API SafeTime {
226 framepos_t timestamp;
239 class LIBARDOUR_API TimecodeSlave : public Slave {
243 virtual Timecode::TimecodeFormat apparent_timecode_format() const = 0;
245 /* this is intended to be used by a UI and polled from a timeout. it should
246 return a string describing the current position of the TC source. it
247 should NOT do any computation, but should use a cached value
248 of the TC source position.
250 virtual std::string approximate_current_position() const = 0;
252 framepos_t timecode_offset;
253 bool timecode_negative_offset;
256 class LIBARDOUR_API MTC_Slave : public TimecodeSlave {
258 MTC_Slave (Session&, MidiPort&);
261 void rebind (MidiPort&);
262 bool speed_and_position (double&, framepos_t&);
266 void handle_locate (const MIDI::byte*);
268 framecnt_t resolution () const;
269 bool requires_seekahead () const { return false; }
270 framecnt_t seekahead_distance() const;
271 bool give_slave_full_control_over_transport_speed() const;
273 Timecode::TimecodeFormat apparent_timecode_format() const;
274 std::string approximate_current_position() const;
275 std::string approximate_current_delta() const;
280 PBD::ScopedConnectionList port_connections;
281 PBD::ScopedConnection config_connection;
282 bool can_notify_on_unknown_rate;
284 static const int frame_tolerance;
287 framepos_t mtc_frame; /* current time */
288 double mtc_frame_dll;
289 framepos_t last_inbound_frame; /* when we got it; audio clocked */
290 MIDI::byte last_mtc_fps_byte;
291 framepos_t window_begin;
292 framepos_t window_end;
293 framepos_t first_mtc_timestamp;
294 bool did_reset_tc_format;
295 Timecode::TimecodeFormat saved_tc_format;
296 Glib::Threads::Mutex reset_lock;
297 uint32_t reset_pending;
299 int transport_direction;
303 double speedup_due_to_tc_mismatch;
304 double quarter_frame_duration;
305 Timecode::TimecodeFormat mtc_timecode;
306 Timecode::TimecodeFormat a3e_timecode;
307 Timecode::Time timecode;
308 bool printed_timecode_warning;
309 frameoffset_t current_delta;
311 /* DLL - chase MTC */
312 double t0; ///< time at the beginning of the MTC quater frame
313 double t1; ///< calculated end of the MTC quater frame
314 double e2; ///< second order loop error
315 double b, c, omega; ///< DLL filter coefficients
317 /* DLL - sync engine */
318 int engine_dll_initstate;
319 double te0; ///< time at the beginning of the engine process
320 double te1; ///< calculated sync time
321 double ee2; ///< second order loop error
322 double be, ce, oe; ///< DLL filter coefficients
324 void reset (bool with_pos);
325 void queue_reset (bool with_pos);
328 void update_mtc_qtr (MIDI::Parser&, int, framepos_t);
329 void update_mtc_time (const MIDI::byte *, bool, framepos_t);
330 void update_mtc_status (MIDI::MTC_Status);
331 void read_current (SafeTime *) const;
332 void reset_window (framepos_t);
333 bool outside_window (framepos_t) const;
334 void init_mtc_dll(framepos_t, double);
335 void init_engine_dll (framepos_t, framepos_t);
336 void parse_timecode_offset();
337 void parameter_changed(std::string const & p);
340 class LIBARDOUR_API LTC_Slave : public TimecodeSlave {
342 LTC_Slave (Session&);
345 bool speed_and_position (double&, framepos_t&);
350 framecnt_t resolution () const;
351 bool requires_seekahead () const { return false; }
352 framecnt_t seekahead_distance () const { return 0; }
353 bool give_slave_full_control_over_transport_speed() const { return true; }
355 Timecode::TimecodeFormat apparent_timecode_format() const;
356 std::string approximate_current_position() const;
357 std::string approximate_current_delta() const;
360 void parse_ltc(const pframes_t, const Sample* const, const framecnt_t);
361 void process_ltc(framepos_t const);
362 void init_engine_dll (framepos_t, int32_t);
363 bool detect_discontinuity(LTCFrameExt *, int, bool);
364 bool detect_ltc_fps(int, bool);
365 bool equal_ltc_frame_time(LTCFrame *a, LTCFrame *b);
368 void resync_latency();
369 void parse_timecode_offset();
370 void parameter_changed(std::string const & p);
373 bool did_reset_tc_format;
374 Timecode::TimecodeFormat saved_tc_format;
376 LTCDecoder * decoder;
377 double frames_per_ltc_frame;
378 Timecode::Time timecode;
379 LTCFrameExt prev_frame;
382 framecnt_t monotonic_cnt;
383 framecnt_t last_timestamp;
384 framecnt_t last_ltc_frame;
386 frameoffset_t current_delta;
389 int ltc_detect_fps_cnt;
390 int ltc_detect_fps_max;
391 bool printed_timecode_warning;
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; }
517 #endif /* __ardour_slave_h__ */