2 Copyright (C) 2008 Paul Davis
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include <sys/types.h>
26 #include "pbd/error.h"
27 #include "pbd/failed_constructor.h"
28 #include "pbd/pthread_utils.h"
30 #include "midi++/port.h"
32 #include "ardour/debug.h"
33 #include "ardour/slave.h"
34 #include "ardour/session.h"
35 #include "ardour/audioengine.h"
36 #include "ardour/cycles.h"
37 #include "ardour/tempo.h"
43 using namespace ARDOUR
;
47 MIDIClock_Slave::MIDIClock_Slave (Session
& s
, MIDI::Port
& p
, int ppqn
)
49 , bandwidth (1.0 / 60.0) // 1 BpM = 1 / 60 Hz
51 session
= (ISlaveSessionProxy
*) new SlaveSessionProxy(s
);
56 MIDIClock_Slave::MIDIClock_Slave (ISlaveSessionProxy
* session_proxy
, int ppqn
)
57 : session(session_proxy
)
59 , bandwidth (1.0 / 60.0) // 1 BpM = 1 / 60 Hz
64 MIDIClock_Slave::~MIDIClock_Slave()
70 MIDIClock_Slave::rebind (MIDI::Port
& p
)
72 port_connections
.drop_connections();
76 DEBUG_TRACE (DEBUG::MidiClock
, string_compose ("MIDIClock_Slave: connecting to port %1\n", port
->name()));
78 port
->parser()->timing
.connect_same_thread (port_connections
, boost::bind (&MIDIClock_Slave::update_midi_clock
, this, _1
, _2
));
79 port
->parser()->start
.connect_same_thread (port_connections
, boost::bind (&MIDIClock_Slave::start
, this, _1
, _2
));
80 port
->parser()->contineu
.connect_same_thread (port_connections
, boost::bind (&MIDIClock_Slave::contineu
, this, _1
, _2
));
81 port
->parser()->stop
.connect_same_thread (port_connections
, boost::bind (&MIDIClock_Slave::stop
, this, _1
, _2
));
82 port
->parser()->position
.connect_same_thread (port_connections
, boost::bind (&MIDIClock_Slave::position
, this, _1
, _2
, 3));
86 MIDIClock_Slave::calculate_one_ppqn_in_frames_at(framepos_t time
)
88 const Tempo
& current_tempo
= session
->tempo_map().tempo_at(time
);
89 const Meter
& current_meter
= session
->tempo_map().meter_at(time
);
90 double frames_per_beat
=
91 current_tempo
.frames_per_beat(session
->frame_rate(),
94 double quarter_notes_per_beat
= 4.0 / current_tempo
.note_type();
95 double frames_per_quarter_note
= frames_per_beat
/ quarter_notes_per_beat
;
97 one_ppqn_in_frames
= frames_per_quarter_note
/ double (ppqn
);
98 // DEBUG_TRACE (DEBUG::MidiClock, string_compose ("at %1, one ppqn = %2\n", time, one_ppqn_in_frames));
102 MIDIClock_Slave::calculate_song_position(uint16_t song_position_in_sixteenth_notes
)
104 framepos_t song_position_frames
= 0;
105 for (uint16_t i
= 1; i
<= song_position_in_sixteenth_notes
; ++i
) {
106 // one quarter note contains ppqn pulses, so a sixteenth note is ppqn / 4 pulses
107 calculate_one_ppqn_in_frames_at(song_position_frames
);
108 song_position_frames
+= one_ppqn_in_frames
* (framepos_t
)(ppqn
/ 4);
111 return song_position_frames
;
115 MIDIClock_Slave::calculate_filter_coefficients()
117 // omega = 2 * PI * Bandwidth / MIDI clock frame frequency in Hz
118 omega
= 2.0 * M_PI
* bandwidth
* one_ppqn_in_frames
/ session
->frame_rate();
119 b
= 1.4142135623730950488 * omega
;
124 MIDIClock_Slave::update_midi_clock (Parser
& /*parser*/, framepos_t timestamp
)
126 // some pieces of hardware send MIDI Clock all the time
127 if ( (!_starting
) && (!_started
) ) {
131 calculate_one_ppqn_in_frames_at(should_be_position
);
133 framepos_t elapsed_since_start
= timestamp
- first_timestamp
;
136 if (_starting
|| last_timestamp
== 0) {
137 midi_clock_count
= 0;
139 first_timestamp
= timestamp
;
140 elapsed_since_start
= should_be_position
;
142 // calculate filter coefficients
143 calculate_filter_coefficients();
146 e2
= double(one_ppqn_in_frames
) / double(session
->frame_rate());
147 t0
= double(elapsed_since_start
) / double(session
->frame_rate());
150 // let ardour go after first MIDI Clock Event
154 should_be_position
+= one_ppqn_in_frames
;
155 calculate_filter_coefficients();
157 // calculate loop error
158 // we use session->audible_frame() instead of t1 here
159 // because t1 is used to calculate the transport speed,
160 // so the loop will compensate for accumulating rounding errors
161 error
= (double(should_be_position
) - double(session
->audible_frame()));
162 e
= error
/ double(session
->frame_rate());
170 DEBUG_TRACE (DEBUG::MidiClock
, string_compose ("clock #%1 @ %2 arrived %3 (theoretical) audible %4 transport %5 error %6 "
171 "read delta %7 should-be delta %8 t1-t0 %9 t0 %10 t1 %11 framerate %12 appspeed %13\n",
175 session
->audible_frame(),
176 session
->transport_frame(),
178 timestamp
- last_timestamp
,
180 (t1
-t0
) * session
->frame_rate(),
181 t0
* session
->frame_rate(),
182 t1
* session
->frame_rate(),
183 session
->frame_rate(),
184 ((t1
- t0
) * session
->frame_rate()) / one_ppqn_in_frames
));
186 last_timestamp
= timestamp
;
190 MIDIClock_Slave::start (Parser
& /*parser*/, framepos_t timestamp
)
192 DEBUG_TRACE (DEBUG::MidiClock
, string_compose ("MIDIClock_Slave got start message at time %1 engine time %2\n", timestamp
, session
->frame_time()));
200 should_be_position
= session
->transport_frame();
205 MIDIClock_Slave::reset ()
207 should_be_position
= session
->transport_frame();
213 // session->request_locate(0, false);
217 MIDIClock_Slave::contineu (Parser
& /*parser*/, framepos_t
/*timestamp*/)
219 DEBUG_TRACE (DEBUG::MidiClock
, "MIDIClock_Slave got continue message\n");
229 MIDIClock_Slave::stop (Parser
& /*parser*/, framepos_t
/*timestamp*/)
231 DEBUG_TRACE (DEBUG::MidiClock
, "MIDIClock_Slave got stop message\n");
233 if (_started
|| _starting
) {
236 // locate to last MIDI clock position
237 session
->request_transport_speed(0.0);
239 // we need to go back to the last MIDI beat (6 ppqn)
240 // and lets hope the tempo didnt change in the meantime :)
242 // begin at the should be position, because
243 // that is the position of the last MIDI Clock
244 // message and that is probably what the master
245 // expects where we are right now
246 framepos_t stop_position
= should_be_position
;
248 // find out the last MIDI beat: go back #midi_clocks mod 6
249 // and lets hope the tempo didnt change in those last 6 beats :)
250 stop_position
-= (midi_clock_count
% 6) * one_ppqn_in_frames
;
252 session
->request_locate(stop_position
, false);
253 should_be_position
= stop_position
;
259 MIDIClock_Slave::position (Parser
& /*parser*/, byte
* message
, size_t size
)
261 // we are note supposed to get position messages while we are running
262 // so lets be robust and ignore those
263 if (_started
|| _starting
) {
268 byte lsb
= message
[1];
269 byte msb
= message
[2];
270 assert((lsb
<= 0x7f) && (msb
<= 0x7f));
272 uint16_t position_in_sixteenth_notes
= (uint16_t(msb
) << 7) | uint16_t(lsb
);
273 framepos_t position_in_frames
= calculate_song_position(position_in_sixteenth_notes
);
275 DEBUG_TRACE (DEBUG::MidiClock
, string_compose ("Song Position: %1 frames: %2\n", position_in_sixteenth_notes
, position_in_frames
));
277 session
->request_locate(position_in_frames
, false);
278 should_be_position
= position_in_frames
;
284 MIDIClock_Slave::locked () const
290 MIDIClock_Slave::ok() const
296 MIDIClock_Slave::starting() const
302 MIDIClock_Slave::stop_if_no_more_clock_events(framepos_t
& pos
, framepos_t now
)
304 /* no timecode for 1/4 second ? conclude that its stopped */
305 if (last_timestamp
&&
306 now
> last_timestamp
&&
307 now
- last_timestamp
> session
->frame_rate() / 4) {
308 DEBUG_TRACE (DEBUG::MidiClock
, "No MIDI Clock frames received for some time, stopping!\n");
309 pos
= should_be_position
;
310 session
->request_transport_speed (0);
311 session
->request_locate (should_be_position
, false);
319 MIDIClock_Slave::speed_and_position (double& speed
, framepos_t
& pos
)
321 if (!_started
|| _starting
) {
323 pos
= should_be_position
;
327 framepos_t engine_now
= session
->frame_time();
329 if (stop_if_no_more_clock_events(pos
, engine_now
)) {
334 speed
= ((t1
- t0
) * session
->frame_rate()) / one_ppqn_in_frames
;
336 // provide a 3% deadzone to lock the speed
337 if (fabs(speed
- 1.0) <= 0.03)
340 // calculate position
341 if (engine_now
> last_timestamp
) {
342 // we are in between MIDI clock messages
343 // so we interpolate position according to speed
344 framecnt_t elapsed
= engine_now
- last_timestamp
;
345 pos
= (framepos_t
) (should_be_position
+ double(elapsed
) * speed
);
347 // A new MIDI clock message has arrived this cycle
348 pos
= should_be_position
;
351 DEBUG_TRACE (DEBUG::MidiClock
, string_compose ("speed_and_position: %1 & %2 <-> %3 (transport)\n", speed
, pos
, session
->transport_frame()));
357 MIDIClock_Slave::resolution() const
360 return (framecnt_t
) one_ppqn_in_frames
* ppqn
;