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"
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 ? " " : (A)<10000 ? " " : "" )
55 * @brief The Slave interface can be used to sync ARDOURs tempo to an external source
56 * like MTC, MIDI Clock, etc.
58 * The name of the interface may be a bit misleading: A subclass of Slave actually
59 * acts as a time master for ARDOUR, that means ARDOUR will try to follow the
60 * speed and transport position of the implementation of Slave.
61 * Therefore it is rather that class, that makes ARDOUR a slave by connecting it
62 * to its external time master.
70 * This is the most important function to implement:
71 * Each process cycle, Session::follow_slave will call this method.
72 * and after the method call they should
74 * Session::follow_slave will then try to follow the given
75 * <em>position</em> using a delay locked loop (DLL),
76 * starting with the first given transport speed.
77 * If the values of speed and position contradict each other,
78 * ARDOUR will always follow the position and disregard the speed.
79 * Although, a correct speed is important so that ARDOUR
80 * can sync to the master time source quickly.
82 * For background information on delay locked loops,
83 * see http://www.kokkinizita.net/papers/usingdll.pdf
85 * The method has the following precondition:
88 * Slave::ok() should return true, otherwise playback will stop
89 * immediately and the method will not be called
92 * when the references speed and position are passed into the Slave
93 * they are uninitialized
97 * After the method call the following postconditions should be met:
100 * The first position value on transport start should be 0,
101 * otherwise ARDOUR will try to locate to the new position
102 * rather than move to it
105 * the references speed and position should be assigned
106 * to the Slaves current requested transport speed
107 * and transport position.
110 * Slave::resolution() should be greater than the maximum distance of
111 * ARDOURs transport position to the slaves requested transport position.
113 * <li>Slave::locked() should return true, otherwise Session::no_roll will be called</li>
114 * <li>Slave::starting() should be false, otherwise the transport will not move until it becomes true</li> *
117 * @param speed - The transport speed requested
118 * @param position - The transport position requested
119 * @return - The return value is currently ignored (see Session::follow_slave)
121 virtual bool speed_and_position (double& speed, framepos_t& position) = 0;
124 * reports to ARDOUR whether the Slave is currently synced to its external
127 * @return - when returning false, the transport will stop rolling
129 virtual bool locked() const = 0;
132 * reports to ARDOUR whether the slave is in a sane state
134 * @return - when returning false, the transport will be stopped and the slave
135 * disconnected from ARDOUR.
137 virtual bool ok() const = 0;
140 * reports to ARDOUR whether the slave is in the process of starting
143 * @return - when returning false, transport will not move until this method returns true
145 virtual bool starting() const { return false; }
148 * @return - the timing resolution of the Slave - If the distance of ARDOURs transport
149 * to the slave becomes greater than the resolution, sound will stop
151 virtual framecnt_t resolution() const = 0;
154 * @return - when returning true, ARDOUR will wait for seekahead_distance() before transport
157 virtual bool requires_seekahead () const = 0;
160 * @return the number of frames that this slave wants to seek ahead. Relevant
161 * only if requires_seekahead() returns true.
164 virtual framecnt_t seekahead_distance() const { return 0; }
167 * @return - when returning true, ARDOUR will use transport speed 1.0 no matter what
170 virtual bool is_always_synced() const { return false; }
173 * @return - whether ARDOUR should use the slave speed without any adjustments
175 virtual bool give_slave_full_control_over_transport_speed() const { return false; }
178 * @return - current time-delta between engine and sync-source
180 virtual std::string approximate_current_delta() const { return ""; }
184 /// We need this wrapper for testability, it's just too hard to mock up a session class
185 class ISlaveSessionProxy {
187 virtual ~ISlaveSessionProxy() {}
188 virtual TempoMap& tempo_map() const { return *((TempoMap *) 0); }
189 virtual framecnt_t frame_rate() 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 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 SlaveSessionProxy : public ISlaveSessionProxy {
207 SlaveSessionProxy(Session &s) : session(s) {}
209 TempoMap& tempo_map() const;
210 framecnt_t frame_rate() const;
211 framepos_t audible_frame () const;
212 framepos_t transport_frame () const;
213 pframes_t frames_since_cycle_start () const;
214 framepos_t frame_time () const;
216 void request_locate (framepos_t frame, bool with_roll = false);
217 void request_transport_speed (double speed);
223 framepos_t timestamp;
236 class TimecodeSlave : public Slave {
240 virtual Timecode::TimecodeFormat apparent_timecode_format() const = 0;
242 /* this is intended to be used by a UI and polled from a timeout. it should
243 return a string describing the current position of the TC source. it
244 should NOT do any computation, but should use a cached value
245 of the TC source position.
247 virtual std::string approximate_current_position() const = 0;
249 framepos_t timecode_offset;
250 bool timecode_negative_offset;
253 class MTC_Slave : public TimecodeSlave {
255 MTC_Slave (Session&, MIDI::Port&);
258 void rebind (MIDI::Port&);
259 bool speed_and_position (double&, framepos_t&);
263 void handle_locate (const MIDI::byte*);
265 framecnt_t resolution () const;
266 bool requires_seekahead () const { return false; }
267 framecnt_t seekahead_distance() const;
268 bool give_slave_full_control_over_transport_speed() const;
270 Timecode::TimecodeFormat apparent_timecode_format() const;
271 std::string approximate_current_position() const;
272 std::string approximate_current_delta() const;
277 PBD::ScopedConnectionList port_connections;
278 PBD::ScopedConnection config_connection;
279 bool can_notify_on_unknown_rate;
281 static const int frame_tolerance;
284 framepos_t mtc_frame; /* current time */
285 framepos_t last_inbound_frame; /* when we got it; audio clocked */
286 MIDI::byte last_mtc_fps_byte;
287 framepos_t window_begin;
288 framepos_t window_end;
289 framepos_t first_mtc_timestamp;
290 bool did_reset_tc_format;
291 Timecode::TimecodeFormat saved_tc_format;
292 Glib::Threads::Mutex reset_lock;
293 uint32_t reset_pending;
295 int transport_direction;
299 double speedup_due_to_tc_mismatch;
300 double quarter_frame_duration;
301 Timecode::TimecodeFormat mtc_timecode;
302 Timecode::TimecodeFormat a3e_timecode;
303 Timecode::Time timecode;
304 bool printed_timecode_warning;
305 frameoffset_t current_delta;
307 /* DLL - chase MTC */
308 double t0; ///< time at the beginning of the MTC quater frame
309 double t1; ///< calculated end of the MTC quater frame
310 double e2; ///< second order loop error
311 double b, c, omega; ///< DLL filter coefficients
313 /* DLL - sync engine */
314 int engine_dll_initstate;
315 double te0; ///< time at the beginning of the engine process
316 double te1; ///< calculated sync time
317 double ee2; ///< second order loop error
318 double be, ce, oe; ///< DLL filter coefficients
320 void reset (bool with_pos);
321 void queue_reset (bool with_pos);
324 void update_mtc_qtr (MIDI::Parser&, int, framepos_t);
325 void update_mtc_time (const MIDI::byte *, bool, framepos_t);
326 void update_mtc_status (MIDI::MTC_Status);
327 void read_current (SafeTime *) const;
328 void reset_window (framepos_t);
329 bool outside_window (framepos_t) const;
330 void init_mtc_dll(framepos_t, double);
331 void init_engine_dll (framepos_t, framepos_t);
332 void parse_timecode_offset();
333 void parameter_changed(std::string const & p);
336 class LTC_Slave : public TimecodeSlave {
338 LTC_Slave (Session&);
341 bool speed_and_position (double&, framepos_t&);
346 framecnt_t resolution () const;
347 bool requires_seekahead () const { return false; }
348 framecnt_t seekahead_distance () const { return 0; }
349 bool give_slave_full_control_over_transport_speed() const { return true; }
351 Timecode::TimecodeFormat apparent_timecode_format() const;
352 std::string approximate_current_position() const;
353 std::string approximate_current_delta() const;
356 void parse_ltc(const jack_nframes_t, const jack_default_audio_sample_t * const, const framecnt_t);
357 void process_ltc(framepos_t const);
358 void init_engine_dll (framepos_t, int32_t);
359 bool detect_discontinuity(LTCFrameExt *, int, bool);
360 bool detect_ltc_fps(int, bool);
361 bool equal_ltc_frame_time(LTCFrame *a, LTCFrame *b);
364 void resync_latency();
365 void parse_timecode_offset();
366 void parameter_changed(std::string const & p);
369 bool did_reset_tc_format;
370 Timecode::TimecodeFormat saved_tc_format;
372 LTCDecoder * decoder;
373 double frames_per_ltc_frame;
374 Timecode::Time timecode;
375 LTCFrameExt prev_frame;
378 framecnt_t monotonic_cnt;
379 framecnt_t last_timestamp;
380 framecnt_t last_ltc_frame;
382 frameoffset_t current_delta;
385 int ltc_detect_fps_cnt;
386 int ltc_detect_fps_max;
387 bool printed_timecode_warning;
388 Timecode::TimecodeFormat ltc_timecode;
389 Timecode::TimecodeFormat a3e_timecode;
391 PBD::ScopedConnectionList port_connections;
392 PBD::ScopedConnection config_connection;
393 jack_latency_range_t ltc_slave_latency;
395 /* DLL - chase LTC */
396 int transport_direction;
397 int engine_dll_initstate;
398 double t0; ///< time at the beginning of the MTC quater frame
399 double t1; ///< calculated end of the MTC quater frame
400 double e2; ///< second order loop error
401 double b, c; ///< DLL filter coefficients
404 class MIDIClock_Slave : public Slave {
406 MIDIClock_Slave (Session&, MIDI::Port&, int ppqn = 24);
408 /// Constructor for unit tests
409 MIDIClock_Slave (ISlaveSessionProxy* session_proxy = 0, int ppqn = 24);
412 void rebind (MIDI::Port&);
413 bool speed_and_position (double&, framepos_t&);
417 bool starting() const;
419 framecnt_t resolution () const;
420 bool requires_seekahead () const { return false; }
421 bool give_slave_full_control_over_transport_speed() const { return true; }
423 void set_bandwidth (double a_bandwith) { bandwidth = a_bandwith; }
424 std::string approximate_current_delta() const;
427 ISlaveSessionProxy* session;
429 PBD::ScopedConnectionList port_connections;
431 /// pulses per quarter note for one MIDI clock frame (default 24)
434 /// the duration of one ppqn in frame time
435 double one_ppqn_in_frames;
437 /// the timestamp of the first MIDI clock message
438 framepos_t first_timestamp;
440 /// the time stamp and should-be transport position of the last inbound MIDI clock message
441 framepos_t last_timestamp;
442 double should_be_position;
444 /// the number of midi clock messages received (zero-based)
446 long midi_clock_count;
448 //the delay locked loop (DLL), see www.kokkinizita.net/papers/usingdll.pdf
450 /// time at the beginning of the MIDI clock frame
453 /// calculated end of the MIDI clock frame
456 /// loop error = real value - expected value
459 /// second order loop error
462 /// DLL filter bandwidth
465 /// DLL filter coefficients
468 frameoffset_t current_delta;
471 void start (MIDI::Parser& parser, framepos_t timestamp);
472 void contineu (MIDI::Parser& parser, framepos_t timestamp);
473 void stop (MIDI::Parser& parser, framepos_t timestamp);
474 void position (MIDI::Parser& parser, MIDI::byte* message, size_t size);
475 // we can't use continue because it is a C++ keyword
476 void calculate_one_ppqn_in_frames_at(framepos_t time);
477 framepos_t calculate_song_position(uint16_t song_position_in_sixteenth_notes);
478 void calculate_filter_coefficients();
479 void update_midi_clock (MIDI::Parser& parser, framepos_t timestamp);
480 void read_current (SafeTime *) const;
481 bool stop_if_no_more_clock_events(framepos_t& pos, framepos_t now);
483 /// whether transport should be rolling
486 /// is true if the MIDI Start message has just been received until
487 /// the first MIDI Clock Event
491 class JACK_Slave : public Slave
494 JACK_Slave (jack_client_t*);
497 bool speed_and_position (double& speed, framepos_t& pos);
499 bool starting() const { return _starting; }
502 framecnt_t resolution () const { return 1; }
503 bool requires_seekahead () const { return false; }
504 void reset_client (jack_client_t* jack);
505 bool is_always_synced() const { return true; }
515 #endif /* __ardour_slave_h__ */