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;
251 framepos_t timecode_offset;
252 bool timecode_negative_offset;
255 class MTC_Slave : public TimecodeSlave {
257 MTC_Slave (Session&, MIDI::Port&);
260 void rebind (MIDI::Port&);
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 framepos_t last_inbound_frame; /* when we got it; audio clocked */
288 MIDI::byte last_mtc_fps_byte;
289 framepos_t window_begin;
290 framepos_t window_end;
291 framepos_t first_mtc_timestamp;
292 bool did_reset_tc_format;
293 Timecode::TimecodeFormat saved_tc_format;
294 Glib::Threads::Mutex reset_lock;
295 uint32_t reset_pending;
297 int transport_direction;
301 double speedup_due_to_tc_mismatch;
302 double quarter_frame_duration;
303 Timecode::TimecodeFormat mtc_timecode;
304 Timecode::TimecodeFormat a3e_timecode;
305 Timecode::Time timecode;
306 bool printed_timecode_warning;
307 frameoffset_t current_delta;
309 /* DLL - chase MTC */
310 double t0; ///< time at the beginning of the MTC quater frame
311 double t1; ///< calculated end of the MTC quater frame
312 double e2; ///< second order loop error
313 double b, c, omega; ///< DLL filter coefficients
315 /* DLL - sync engine */
316 int engine_dll_initstate;
317 double te0; ///< time at the beginning of the engine process
318 double te1; ///< calculated sync time
319 double ee2; ///< second order loop error
320 double be, ce, oe; ///< DLL filter coefficients
322 void reset (bool with_pos);
323 void queue_reset (bool with_pos);
326 void update_mtc_qtr (MIDI::Parser&, int, framepos_t);
327 void update_mtc_time (const MIDI::byte *, bool, framepos_t);
328 void update_mtc_status (MIDI::MTC_Status);
329 void read_current (SafeTime *) const;
330 void reset_window (framepos_t);
331 bool outside_window (framepos_t) const;
332 void init_mtc_dll(framepos_t, double);
333 void init_engine_dll (framepos_t, framepos_t);
334 void parse_timecode_offset();
335 void parameter_changed(std::string const & p);
339 class 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 jack_nframes_t, const jack_default_audio_sample_t * 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 Timecode::TimecodeFormat ltc_timecode;
392 Timecode::TimecodeFormat a3e_timecode;
394 PBD::ScopedConnectionList port_connections;
395 PBD::ScopedConnection config_connection;
396 jack_latency_range_t ltc_slave_latency;
398 /* DLL - chase LTC */
399 int transport_direction;
400 int engine_dll_initstate;
401 double t0; ///< time at the beginning of the MTC quater frame
402 double t1; ///< calculated end of the MTC quater frame
403 double e2; ///< second order loop error
404 double b, c; ///< DLL filter coefficients
408 class MIDIClock_Slave : public Slave {
410 MIDIClock_Slave (Session&, MIDI::Port&, int ppqn = 24);
412 /// Constructor for unit tests
413 MIDIClock_Slave (ISlaveSessionProxy* session_proxy = 0, int ppqn = 24);
416 void rebind (MIDI::Port&);
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;
433 PBD::ScopedConnectionList port_connections;
435 /// pulses per quarter note for one MIDI clock frame (default 24)
438 /// the duration of one ppqn in frame time
439 double one_ppqn_in_frames;
441 /// the timestamp of the first MIDI clock message
442 framepos_t first_timestamp;
444 /// the time stamp and should-be transport position of the last inbound MIDI clock message
445 framepos_t last_timestamp;
446 double should_be_position;
448 /// the number of midi clock messages received (zero-based)
450 long midi_clock_count;
452 //the delay locked loop (DLL), see www.kokkinizita.net/papers/usingdll.pdf
454 /// time at the beginning of the MIDI clock frame
457 /// calculated end of the MIDI clock frame
460 /// loop error = real value - expected value
463 /// second order loop error
466 /// DLL filter bandwidth
469 /// DLL filter coefficients
472 frameoffset_t current_delta;
475 void start (MIDI::Parser& parser, framepos_t timestamp);
476 void contineu (MIDI::Parser& parser, framepos_t timestamp);
477 void stop (MIDI::Parser& parser, framepos_t timestamp);
478 void position (MIDI::Parser& parser, MIDI::byte* message, size_t size);
479 // we can't use continue because it is a C++ keyword
480 void calculate_one_ppqn_in_frames_at(framepos_t time);
481 framepos_t calculate_song_position(uint16_t song_position_in_sixteenth_notes);
482 void calculate_filter_coefficients();
483 void update_midi_clock (MIDI::Parser& parser, framepos_t timestamp);
484 void read_current (SafeTime *) const;
485 bool stop_if_no_more_clock_events(framepos_t& pos, framepos_t now);
487 /// whether transport should be rolling
490 /// is true if the MIDI Start message has just been received until
491 /// the first MIDI Clock Event
495 class JACK_Slave : public Slave
498 JACK_Slave (jack_client_t*);
501 bool speed_and_position (double& speed, framepos_t& pos);
503 bool starting() const { return _starting; }
506 framecnt_t resolution () const { return 1; }
507 bool requires_seekahead () const { return false; }
508 void reset_client (jack_client_t* jack);
509 bool is_always_synced() const { return true; }
519 #endif /* __ardour_slave_h__ */