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 ? " " : "" )
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.
67 /** The slave should read any incoming information in this method
68 * and use it adjust its current idea of reality. If no such
69 * processing is required, it does need to be implemented.
71 * @param nframes specifies the number of frames-worth of data that
72 * can be read from any ports used by the slave.
74 virtual int process (pframes_t) { return 0; }
77 * This is the most important function to implement:
78 * Each process cycle, Session::follow_slave will call this method.
79 * and after the method call they should
81 * Session::follow_slave will then try to follow the given
82 * <em>position</em> using a delay locked loop (DLL),
83 * starting with the first given transport speed.
84 * If the values of speed and position contradict each other,
85 * ARDOUR will always follow the position and disregard the speed.
86 * Although, a correct speed is important so that ARDOUR
87 * can sync to the master time source quickly.
89 * For background information on delay locked loops,
90 * see http://www.kokkinizita.net/papers/usingdll.pdf
92 * The method has the following precondition:
95 * Slave::ok() should return true, otherwise playback will stop
96 * immediately and the method will not be called
99 * when the references speed and position are passed into the Slave
100 * they are uninitialized
104 * After the method call the following postconditions should be met:
107 * The first position value on transport start should be 0,
108 * otherwise ARDOUR will try to locate to the new position
109 * rather than move to it
112 * the references speed and position should be assigned
113 * to the Slaves current requested transport speed
114 * and transport position.
117 * Slave::resolution() should be greater than the maximum distance of
118 * ARDOURs transport position to the slaves requested transport position.
120 * <li>Slave::locked() should return true, otherwise Session::no_roll will be called</li>
121 * <li>Slave::starting() should be false, otherwise the transport will not move until it becomes true</li> *
124 * @param speed - The transport speed requested
125 * @param position - The transport position requested
126 * @return - The return value is currently ignored (see Session::follow_slave)
128 virtual bool speed_and_position (double& speed, framepos_t& position) = 0;
131 * reports to ARDOUR whether the Slave is currently synced to its external
134 * @return - when returning false, the transport will stop rolling
136 virtual bool locked() const = 0;
139 * reports to ARDOUR whether the slave is in a sane state
141 * @return - when returning false, the transport will be stopped and the slave
142 * disconnected from ARDOUR.
144 virtual bool ok() const = 0;
147 * reports to ARDOUR whether the slave is in the process of starting
150 * @return - when returning false, transport will not move until this method returns true
152 virtual bool starting() const { return false; }
155 * @return - the timing resolution of the Slave - If the distance of ARDOURs transport
156 * to the slave becomes greater than the resolution, sound will stop
158 virtual framecnt_t resolution() const = 0;
161 * @return - when returning true, ARDOUR will wait for seekahead_distance() before transport
164 virtual bool requires_seekahead () const = 0;
167 * @return the number of frames that this slave wants to seek ahead. Relevant
168 * only if requires_seekahead() returns true.
171 virtual framecnt_t seekahead_distance() const { return 0; }
174 * @return - when returning true, ARDOUR will use transport speed 1.0 no matter what
177 virtual bool is_always_synced() const { return false; }
180 * @return - whether ARDOUR should use the slave speed without any adjustments
182 virtual bool give_slave_full_control_over_transport_speed() const { return false; }
185 * @return - current time-delta between engine and sync-source
187 virtual std::string approximate_current_delta() const { return ""; }
191 /// We need this wrapper for testability, it's just too hard to mock up a session class
192 class ISlaveSessionProxy {
194 virtual ~ISlaveSessionProxy() {}
195 virtual TempoMap& tempo_map() const { return *((TempoMap *) 0); }
196 virtual framecnt_t frame_rate() const { return 0; }
197 virtual framepos_t audible_frame () const { return 0; }
198 virtual framepos_t transport_frame () const { return 0; }
199 virtual pframes_t frames_since_cycle_start () const { return 0; }
200 virtual framepos_t frame_time () const { return 0; }
202 virtual void request_locate (framepos_t /*frame*/, bool with_roll = false) {
205 virtual void request_transport_speed (double /*speed*/) {}
209 /// The Session Proxy for use in real Ardour
210 class SlaveSessionProxy : public ISlaveSessionProxy {
214 SlaveSessionProxy(Session &s) : session(s) {}
216 TempoMap& tempo_map() const;
217 framecnt_t frame_rate() const;
218 framepos_t audible_frame () const;
219 framepos_t transport_frame () const;
220 pframes_t frames_since_cycle_start () const;
221 framepos_t frame_time () const;
223 void request_locate (framepos_t frame, bool with_roll = false);
224 void request_transport_speed (double speed);
230 framepos_t timestamp;
243 class TimecodeSlave : public Slave {
247 virtual Timecode::TimecodeFormat apparent_timecode_format() const = 0;
249 /* this is intended to be used by a UI and polled from a timeout. it should
250 return a string describing the current position of the TC source. it
251 should NOT do any computation, but should use a cached value
252 of the TC source position.
254 virtual std::string approximate_current_position() const = 0;
256 framepos_t timecode_offset;
257 bool timecode_negative_offset;
260 class MTC_Slave : public TimecodeSlave {
262 MTC_Slave (Session&, MidiPort&);
265 void rebind (MidiPort&);
266 int process (pframes_t);
267 bool speed_and_position (double&, framepos_t&);
271 void handle_locate (const MIDI::byte*);
273 framecnt_t resolution () const;
274 bool requires_seekahead () const { return false; }
275 framecnt_t seekahead_distance() const;
276 bool give_slave_full_control_over_transport_speed() const;
278 Timecode::TimecodeFormat apparent_timecode_format() const;
279 std::string approximate_current_position() const;
280 std::string approximate_current_delta() const;
286 PBD::ScopedConnectionList port_connections;
287 PBD::ScopedConnection config_connection;
288 bool can_notify_on_unknown_rate;
290 static const int frame_tolerance;
293 framepos_t mtc_frame; /* current time */
294 double mtc_frame_dll;
295 framepos_t last_inbound_frame; /* when we got it; audio clocked */
296 MIDI::byte last_mtc_fps_byte;
297 framepos_t window_begin;
298 framepos_t window_end;
299 framepos_t first_mtc_timestamp;
300 bool did_reset_tc_format;
301 Timecode::TimecodeFormat saved_tc_format;
302 Glib::Threads::Mutex reset_lock;
303 uint32_t reset_pending;
305 int transport_direction;
309 double speedup_due_to_tc_mismatch;
310 double quarter_frame_duration;
311 Timecode::TimecodeFormat mtc_timecode;
312 Timecode::TimecodeFormat a3e_timecode;
313 Timecode::Time timecode;
314 bool printed_timecode_warning;
315 frameoffset_t current_delta;
317 /* DLL - chase MTC */
318 double t0; ///< time at the beginning of the MTC quater frame
319 double t1; ///< calculated end of the MTC quater frame
320 double e2; ///< second order loop error
321 double b, c, omega; ///< DLL filter coefficients
323 /* DLL - sync engine */
324 int engine_dll_initstate;
325 double te0; ///< time at the beginning of the engine process
326 double te1; ///< calculated sync time
327 double ee2; ///< second order loop error
328 double be, ce, oe; ///< DLL filter coefficients
330 void reset (bool with_pos);
331 void queue_reset (bool with_pos);
334 void update_mtc_qtr (MIDI::Parser&, int, framepos_t);
335 void update_mtc_time (const MIDI::byte *, bool, framepos_t);
336 void update_mtc_status (MIDI::MTC_Status);
337 void read_current (SafeTime *) const;
338 void reset_window (framepos_t);
339 bool outside_window (framepos_t) const;
340 void init_mtc_dll(framepos_t, double);
341 void init_engine_dll (framepos_t, framepos_t);
342 void parse_timecode_offset();
343 void parameter_changed(std::string const & p);
346 class LTC_Slave : public TimecodeSlave {
348 LTC_Slave (Session&);
351 bool speed_and_position (double&, framepos_t&);
356 framecnt_t resolution () const;
357 bool requires_seekahead () const { return false; }
358 framecnt_t seekahead_distance () const { return 0; }
359 bool give_slave_full_control_over_transport_speed() const { return true; }
361 Timecode::TimecodeFormat apparent_timecode_format() const;
362 std::string approximate_current_position() const;
363 std::string approximate_current_delta() const;
366 void parse_ltc(const jack_nframes_t, const jack_default_audio_sample_t * const, const framecnt_t);
367 void process_ltc(framepos_t const);
368 void init_engine_dll (framepos_t, int32_t);
369 bool detect_discontinuity(LTCFrameExt *, int, bool);
370 bool detect_ltc_fps(int, bool);
371 bool equal_ltc_frame_time(LTCFrame *a, LTCFrame *b);
374 void resync_latency();
375 void parse_timecode_offset();
376 void parameter_changed(std::string const & p);
379 bool did_reset_tc_format;
380 Timecode::TimecodeFormat saved_tc_format;
382 LTCDecoder * decoder;
383 double frames_per_ltc_frame;
384 Timecode::Time timecode;
385 LTCFrameExt prev_frame;
388 framecnt_t monotonic_cnt;
389 framecnt_t last_timestamp;
390 framecnt_t last_ltc_frame;
392 frameoffset_t current_delta;
395 int ltc_detect_fps_cnt;
396 int ltc_detect_fps_max;
397 bool printed_timecode_warning;
398 Timecode::TimecodeFormat ltc_timecode;
399 Timecode::TimecodeFormat a3e_timecode;
401 PBD::ScopedConnectionList port_connections;
402 PBD::ScopedConnection config_connection;
403 LatencyRange ltc_slave_latency;
405 /* DLL - chase LTC */
406 int transport_direction;
407 int engine_dll_initstate;
408 double t0; ///< time at the beginning of the MTC quater frame
409 double t1; ///< calculated end of the MTC quater frame
410 double e2; ///< second order loop error
411 double b, c; ///< DLL filter coefficients
414 class MIDIClock_Slave : public Slave {
416 MIDIClock_Slave (Session&, MidiPort&, int ppqn = 24);
418 /// Constructor for unit tests
419 MIDIClock_Slave (ISlaveSessionProxy* session_proxy = 0, int ppqn = 24);
422 void rebind (MidiPort&);
423 int process (pframes_t);
424 bool speed_and_position (double&, framepos_t&);
428 bool starting() const;
430 framecnt_t resolution () const;
431 bool requires_seekahead () const { return false; }
432 bool give_slave_full_control_over_transport_speed() const { return true; }
434 void set_bandwidth (double a_bandwith) { bandwidth = a_bandwith; }
435 std::string approximate_current_delta() const;
438 ISlaveSessionProxy* session;
441 PBD::ScopedConnectionList port_connections;
443 /// pulses per quarter note for one MIDI clock frame (default 24)
446 /// the duration of one ppqn in frame time
447 double one_ppqn_in_frames;
449 /// the timestamp of the first MIDI clock message
450 framepos_t first_timestamp;
452 /// the time stamp and should-be transport position of the last inbound MIDI clock message
453 framepos_t last_timestamp;
454 double should_be_position;
456 /// the number of midi clock messages received (zero-based)
458 long midi_clock_count;
460 //the delay locked loop (DLL), see www.kokkinizita.net/papers/usingdll.pdf
462 /// time at the beginning of the MIDI clock frame
465 /// calculated end of the MIDI clock frame
468 /// loop error = real value - expected value
471 /// second order loop error
474 /// DLL filter bandwidth
477 /// DLL filter coefficients
480 frameoffset_t current_delta;
483 void start (MIDI::Parser& parser, framepos_t timestamp);
484 void contineu (MIDI::Parser& parser, framepos_t timestamp);
485 void stop (MIDI::Parser& parser, framepos_t timestamp);
486 void position (MIDI::Parser& parser, MIDI::byte* message, size_t size);
487 // we can't use continue because it is a C++ keyword
488 void calculate_one_ppqn_in_frames_at(framepos_t time);
489 framepos_t calculate_song_position(uint16_t song_position_in_sixteenth_notes);
490 void calculate_filter_coefficients();
491 void update_midi_clock (MIDI::Parser& parser, framepos_t timestamp);
492 void read_current (SafeTime *) const;
493 bool stop_if_no_more_clock_events(framepos_t& pos, framepos_t now);
495 /// whether transport should be rolling
498 /// is true if the MIDI Start message has just been received until
499 /// the first MIDI Clock Event
503 class JACK_Slave : public Slave
506 JACK_Slave (AudioEngine&);
509 bool speed_and_position (double& speed, framepos_t& pos);
511 bool starting() const { return _starting; }
514 framecnt_t resolution () const { return 1; }
515 bool requires_seekahead () const { return false; }
516 bool is_always_synced() const { return true; }
526 #endif /* __ardour_slave_h__ */