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>
29 #include "pbd/signals.h"
31 #include "timecode/time.h"
33 #include "ardour/types.h"
34 #include "midi++/parser.h"
35 #include "midi++/types.h"
41 /* used for approximate_current_delta(): */
42 #define PLUSMINUS(A) ( ((A)<0) ? "-" : (((A)>0) ? "+" : "\u00B1") )
43 #define LEADINGZERO(A) ( (A)<10 ? " " : (A)<100 ? " " : (A)<1000 ? " " : (A)<10000 ? " " : "" )
57 * @brief The Slave interface can be used to sync ARDOURs tempo to an external source
58 * like MTC, MIDI Clock, etc.
60 * The name of the interface may be a bit misleading: A subclass of Slave actually
61 * acts as a time master for ARDOUR, that means ARDOUR will try to follow the
62 * speed and transport position of the implementation of Slave.
63 * Therefore it is rather that class, that makes ARDOUR a slave by connecting it
64 * to its external time master.
72 * This is the most important function to implement:
73 * Each process cycle, Session::follow_slave will call this method.
74 * and after the method call they should
76 * Session::follow_slave will then try to follow the given
77 * <em>position</em> using a delay locked loop (DLL),
78 * starting with the first given transport speed.
79 * If the values of speed and position contradict each other,
80 * ARDOUR will always follow the position and disregard the speed.
81 * Although, a correct speed is important so that ARDOUR
82 * can sync to the master time source quickly.
84 * For background information on delay locked loops,
85 * see http://www.kokkinizita.net/papers/usingdll.pdf
87 * The method has the following precondition:
90 * Slave::ok() should return true, otherwise playback will stop
91 * immediately and the method will not be called
94 * when the references speed and position are passed into the Slave
95 * they are uninitialized
99 * After the method call the following postconditions should be met:
102 * The first position value on transport start should be 0,
103 * otherwise ARDOUR will try to locate to the new position
104 * rather than move to it
107 * the references speed and position should be assigned
108 * to the Slaves current requested transport speed
109 * and transport position.
112 * Slave::resolution() should be greater than the maximum distance of
113 * ARDOURs transport position to the slaves requested transport position.
115 * <li>Slave::locked() should return true, otherwise Session::no_roll will be called</li>
116 * <li>Slave::starting() should be false, otherwise the transport will not move until it becomes true</li> *
119 * @param speed - The transport speed requested
120 * @param position - The transport position requested
121 * @return - The return value is currently ignored (see Session::follow_slave)
123 virtual bool speed_and_position (double& speed, framepos_t& position) = 0;
126 * reports to ARDOUR whether the Slave is currently synced to its external
129 * @return - when returning false, the transport will stop rolling
131 virtual bool locked() const = 0;
134 * reports to ARDOUR whether the slave is in a sane state
136 * @return - when returning false, the transport will be stopped and the slave
137 * disconnected from ARDOUR.
139 virtual bool ok() const = 0;
142 * reports to ARDOUR whether the slave is in the process of starting
145 * @return - when returning false, transport will not move until this method returns true
147 virtual bool starting() const { return false; }
150 * @return - the timing resolution of the Slave - If the distance of ARDOURs transport
151 * to the slave becomes greater than the resolution, sound will stop
153 virtual framecnt_t resolution() const = 0;
156 * @return - when returning true, ARDOUR will wait for seekahead_distance() before transport
159 virtual bool requires_seekahead () const = 0;
162 * @return the number of frames that this slave wants to seek ahead. Relevant
163 * only if requires_seekahead() returns true.
166 virtual framecnt_t seekahead_distance() const { return 0; }
169 * @return - when returning true, ARDOUR will use transport speed 1.0 no matter what
172 virtual bool is_always_synced() const { return false; }
175 * @return - whether ARDOUR should use the slave speed without any adjustments
177 virtual bool give_slave_full_control_over_transport_speed() const { return false; }
180 * @return - current time-delta between engine and sync-source
182 virtual std::string approximate_current_delta() const { return ""; }
186 /// We need this wrapper for testability, it's just too hard to mock up a session class
187 class ISlaveSessionProxy {
189 virtual ~ISlaveSessionProxy() {}
190 virtual TempoMap& tempo_map() const { return *((TempoMap *) 0); }
191 virtual framecnt_t frame_rate() const { return 0; }
192 virtual framepos_t audible_frame () const { return 0; }
193 virtual framepos_t transport_frame () const { return 0; }
194 virtual pframes_t frames_since_cycle_start () const { return 0; }
195 virtual framepos_t frame_time () const { return 0; }
197 virtual void request_locate (framepos_t /*frame*/, bool with_roll = false) {
200 virtual void request_transport_speed (double /*speed*/) {}
204 /// The Session Proxy for use in real Ardour
205 class SlaveSessionProxy : public ISlaveSessionProxy {
209 SlaveSessionProxy(Session &s) : session(s) {}
211 TempoMap& tempo_map() const;
212 framecnt_t frame_rate() const;
213 framepos_t audible_frame () const;
214 framepos_t transport_frame () const;
215 pframes_t frames_since_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);
225 framepos_t timestamp;
238 class 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;
252 class MTC_Slave : public TimecodeSlave {
254 MTC_Slave (Session&, MIDI::Port&);
257 void rebind (MIDI::Port&);
258 bool speed_and_position (double&, framepos_t&);
262 void handle_locate (const MIDI::byte*);
264 framecnt_t resolution () const;
265 bool requires_seekahead () const { return false; }
266 framecnt_t seekahead_distance() const;
267 bool give_slave_full_control_over_transport_speed() const;
269 Timecode::TimecodeFormat apparent_timecode_format() const;
270 std::string approximate_current_position() const;
271 std::string approximate_current_delta() const;
276 PBD::ScopedConnectionList port_connections;
277 bool can_notify_on_unknown_rate;
279 static const int frame_tolerance;
282 framepos_t mtc_frame; /* current time */
283 framepos_t last_inbound_frame; /* when we got it; audio clocked */
284 MIDI::byte last_mtc_fps_byte;
285 framepos_t window_begin;
286 framepos_t window_end;
287 framepos_t first_mtc_timestamp;
288 bool did_reset_tc_format;
289 Timecode::TimecodeFormat saved_tc_format;
290 Glib::Threads::Mutex reset_lock;
291 uint32_t reset_pending;
293 int transport_direction;
297 double speedup_due_to_tc_mismatch;
298 double quarter_frame_duration;
299 Timecode::TimecodeFormat mtc_timecode;
300 Timecode::TimecodeFormat a3e_timecode;
301 Timecode::Time timecode;
302 bool printed_timecode_warning;
303 frameoffset_t current_delta;
305 /* DLL - chase MTC */
306 double t0; ///< time at the beginning of the MTC quater frame
307 double t1; ///< calculated end of the MTC quater frame
308 double e2; ///< second order loop error
309 double b, c, omega; ///< DLL filter coefficients
311 /* DLL - sync engine */
312 int engine_dll_initstate;
313 double te0; ///< time at the beginning of the engine process
314 double te1; ///< calculated sync time
315 double ee2; ///< second order loop error
316 double be, ce, oe; ///< DLL filter coefficients
318 void reset (bool with_pos);
319 void queue_reset (bool with_pos);
322 void update_mtc_qtr (MIDI::Parser&, int, framepos_t);
323 void update_mtc_time (const MIDI::byte *, bool, framepos_t);
324 void update_mtc_status (MIDI::MTC_Status);
325 void read_current (SafeTime *) const;
326 void reset_window (framepos_t);
327 bool outside_window (framepos_t) const;
328 void init_mtc_dll(framepos_t, double);
329 void init_engine_dll (framepos_t, framepos_t);
333 class LTC_Slave : public TimecodeSlave {
335 LTC_Slave (Session&);
338 bool speed_and_position (double&, framepos_t&);
343 framecnt_t resolution () const;
344 bool requires_seekahead () const { return false; }
345 framecnt_t seekahead_distance () const { return 0; }
346 bool give_slave_full_control_over_transport_speed() const { return true; }
348 Timecode::TimecodeFormat apparent_timecode_format() const;
349 std::string approximate_current_position() const;
350 std::string approximate_current_delta() const;
353 void parse_ltc(const jack_nframes_t, const jack_default_audio_sample_t * const, const framecnt_t);
354 void process_ltc(framepos_t const);
355 void init_engine_dll (framepos_t, int32_t);
356 bool detect_discontinuity(LTCFrameExt *, int, bool);
357 bool detect_ltc_fps(int, bool);
358 bool equal_ltc_frame_time(LTCFrame *a, LTCFrame *b);
361 void resync_latency();
364 bool did_reset_tc_format;
365 Timecode::TimecodeFormat saved_tc_format;
367 LTCDecoder * decoder;
368 double frames_per_ltc_frame;
369 Timecode::Time timecode;
370 LTCFrameExt prev_frame;
373 framecnt_t monotonic_cnt;
374 framecnt_t last_timestamp;
375 framecnt_t last_ltc_frame;
377 frameoffset_t current_delta;
380 int ltc_detect_fps_cnt;
381 int ltc_detect_fps_max;
382 bool printed_timecode_warning;
383 Timecode::TimecodeFormat ltc_timecode;
384 Timecode::TimecodeFormat a3e_timecode;
386 PBD::ScopedConnectionList port_connections;
387 jack_latency_range_t ltc_slave_latency;
389 /* DLL - chase LTC */
390 int transport_direction;
391 int engine_dll_initstate;
392 double t0; ///< time at the beginning of the MTC quater frame
393 double t1; ///< calculated end of the MTC quater frame
394 double e2; ///< second order loop error
395 double b, c; ///< DLL filter coefficients
399 class MIDIClock_Slave : public Slave {
401 MIDIClock_Slave (Session&, MIDI::Port&, int ppqn = 24);
403 /// Constructor for unit tests
404 MIDIClock_Slave (ISlaveSessionProxy* session_proxy = 0, int ppqn = 24);
407 void rebind (MIDI::Port&);
408 bool speed_and_position (double&, framepos_t&);
412 bool starting() const;
414 framecnt_t resolution () const;
415 bool requires_seekahead () const { return false; }
416 bool give_slave_full_control_over_transport_speed() const { return true; }
418 void set_bandwidth (double a_bandwith) { bandwidth = a_bandwith; }
419 std::string approximate_current_delta() const;
422 ISlaveSessionProxy* session;
424 PBD::ScopedConnectionList port_connections;
426 /// pulses per quarter note for one MIDI clock frame (default 24)
429 /// the duration of one ppqn in frame time
430 double one_ppqn_in_frames;
432 /// the timestamp of the first MIDI clock message
433 framepos_t first_timestamp;
435 /// the time stamp and should-be transport position of the last inbound MIDI clock message
436 framepos_t last_timestamp;
437 double should_be_position;
439 /// the number of midi clock messages received (zero-based)
441 long midi_clock_count;
443 //the delay locked loop (DLL), see www.kokkinizita.net/papers/usingdll.pdf
445 /// time at the beginning of the MIDI clock frame
448 /// calculated end of the MIDI clock frame
451 /// loop error = real value - expected value
454 /// second order loop error
457 /// DLL filter bandwidth
460 /// DLL filter coefficients
463 frameoffset_t current_delta;
466 void start (MIDI::Parser& parser, framepos_t timestamp);
467 void contineu (MIDI::Parser& parser, framepos_t timestamp);
468 void stop (MIDI::Parser& parser, framepos_t timestamp);
469 void position (MIDI::Parser& parser, MIDI::byte* message, size_t size);
470 // we can't use continue because it is a C++ keyword
471 void calculate_one_ppqn_in_frames_at(framepos_t time);
472 framepos_t calculate_song_position(uint16_t song_position_in_sixteenth_notes);
473 void calculate_filter_coefficients();
474 void update_midi_clock (MIDI::Parser& parser, framepos_t timestamp);
475 void read_current (SafeTime *) const;
476 bool stop_if_no_more_clock_events(framepos_t& pos, framepos_t now);
478 /// whether transport should be rolling
481 /// is true if the MIDI Start message has just been received until
482 /// the first MIDI Clock Event
486 class JACK_Slave : public Slave
489 JACK_Slave (jack_client_t*);
492 bool speed_and_position (double& speed, framepos_t& pos);
494 bool starting() const { return _starting; }
497 framecnt_t resolution () const { return 1; }
498 bool requires_seekahead () const { return false; }
499 void reset_client (jack_client_t* jack);
500 bool is_always_synced() const { return true; }
510 #endif /* __ardour_slave_h__ */