libs/ardour/ltc_slave.cc

   1 /*
   2     Copyright (C) 2012 Paul Davis
   3     Witten by 2012 Robin Gareus <robin@gareus.org>
   4
   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.
   9
  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.
  14
  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.
  18
  19 */
  20 #include <iostream>
  21 #include <errno.h>
  22 #include <poll.h>
  23 #include <sys/types.h>
  24 #include <unistd.h>
  25
  26 #include "pbd/error.h"
  27
  28 #include "ardour/debug.h"
  29 #include "ardour/slave.h"
  30 #include "ardour/session.h"
  31 #include "ardour/audioengine.h"
  32 #include "ardour/audio_port.h"
  33
  34 #include "i18n.h"
  35
  36 using namespace std;
  37 using namespace ARDOUR;
  38 using namespace MIDI;
  39 using namespace PBD;
  40 using namespace Timecode;
  41
  42 #define FLYWHEEL_TIMEOUT ( 1 * session.frame_rate() )
  43
  44 LTC_Slave::LTC_Slave (Session& s)
  45         : session (s)
  46 {
  47         frames_per_ltc_frame = session.frames_per_timecode_frame();
  48         timecode.rate = session.timecode_frames_per_second();
  49         timecode.drop  = session.timecode_drop_frames();
  50
  51         did_reset_tc_format = false;
  52         delayedlocked = 10;
  53         monotonic_cnt = 0;
  54
  55         ltc_timecode = timecode_60; // track changes of LTC timecode
  56         a3e_timecode = timecode_60; // track canges of Ardour's timecode
  57         printed_timecode_warning = false;
  58         ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
  59
  60         decoder = ltc_decoder_create((int) frames_per_ltc_frame, 128 /*queue size*/);
  61         reset();
  62 }
  63
  64 LTC_Slave::~LTC_Slave()
  65 {
  66         if (did_reset_tc_format) {
  67                 session.config.set_timecode_format (saved_tc_format);
  68         }
  69
  70         ltc_decoder_free(decoder);
  71 }
  72
  73 ARDOUR::framecnt_t
  74 LTC_Slave::resolution () const
  75 {
  76         return (framecnt_t) (frames_per_ltc_frame);
  77 }
  78
  79 bool
  80 LTC_Slave::locked () const
  81 {
  82         return (delayedlocked < 5);
  83 }
  84
  85 bool
  86 LTC_Slave::ok() const
  87 {
  88         return true;
  89 }
  90
  91 void
  92 LTC_Slave::reset()
  93 {
  94         DEBUG_TRACE (DEBUG::LTC, "LTC reset()\n");
  95         last_timestamp = 0;
  96         current_delta = 0;
  97         transport_direction = 0;
  98         ltc_speed = 0;
  99         engine_dll_initstate = 0;
 100 }
 101
 102 void
 103 LTC_Slave::parse_ltc(const jack_nframes_t nframes, const jack_default_audio_sample_t * const in, const framecnt_t posinfo)
 104 {
 105         jack_nframes_t i;
 106         unsigned char sound[8192];
 107         if (nframes > 8192) {
 108                 /* TODO warn once or wrap, loop conversion below
 109                  * does A3 support > 8192 spp anyway?
 110                  */
 111                 return;
 112         }
 113
 114         for (i = 0; i < nframes; i++) {
 115                 const int snd=(int)rint((127.0*in[i])+128.0);
 116                 sound[i] = (unsigned char) (snd&0xff);
 117         }
 118         ltc_decoder_write(decoder, sound, nframes, posinfo);
 119         return;
 120 }
 121
 122 bool
 123 LTC_Slave::detect_ltc_fps(int frameno, bool df)
 124 {
 125         double detected_fps = 0;
 126         if (frameno > ltc_detect_fps_max)
 127         {
 128                 ltc_detect_fps_max = frameno;
 129         }
 130         ltc_detect_fps_cnt++;
 131
 132         if (ltc_detect_fps_cnt > 40)
 133         {
 134                 if (ltc_detect_fps_cnt > ltc_detect_fps_max
 135                     && (   ceil(timecode.rate) != (ltc_detect_fps_max + 1)
 136                         || timecode.drop != df
 137                         )
 138                     )
 139                 {
 140                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC detected FPS %1%2",
 141                                         ltc_detect_fps_max + 1, timecode.drop ? "df" : ""));
 142                         detected_fps = ltc_detect_fps_max + 1;
 143                         if (df) {
 144                                 /* LTC df -> indicates fractional framerate */
 145                                 detected_fps = detected_fps * 1000.0 / 1001.0;
 146                         }
 147                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC detected FPS: %1%2\n", detected_fps, df?"df":"ndf"));
 148                 }
 149                 ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
 150         }
 151
 152         /* when changed */
 153         if (detected_fps != 0 && (detected_fps != timecode.rate || df != timecode.drop)) {
 154                 timecode.rate = detected_fps;
 155                 timecode.drop = df;
 156                 frames_per_ltc_frame = double(session.frame_rate()) / timecode.rate;
 157                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC reset to FPS: %1%2 ; audio-frames per LTC: %3\n",
 158                                 detected_fps, df?"df":"ndf", frames_per_ltc_frame));
 159                 return true; // reset()
 160         }
 161
 162         /* poll and check session TC */
 163         if (1) {
 164                 TimecodeFormat tc_format = apparent_timecode_format();
 165                 TimecodeFormat cur_timecode = session.config.get_timecode_format();
 166                 if (Config->get_timecode_sync_frame_rate()) {
 167                         /* enforce time-code */
 168                         if (!did_reset_tc_format) {
 169                                 saved_tc_format = cur_timecode;
 170                                 did_reset_tc_format = true;
 171                         }
 172                         if (cur_timecode != tc_format) {
 173                                 warning << string_compose(_("Session framerate adjusted from %1 TO: LTC's %2."),
 174                                                 Timecode::timecode_format_name(cur_timecode),
 175                                                 Timecode::timecode_format_name(tc_format))
 176                                         << endmsg;
 177                                 session.config.set_timecode_format (tc_format);
 178                         }
 179                 } else {
 180                         /* only warn about TC mismatch */
 181                         if (ltc_timecode != tc_format) printed_timecode_warning = false;
 182                         if (a3e_timecode != cur_timecode) printed_timecode_warning = false;
 183
 184                         if (cur_timecode != tc_format && ! printed_timecode_warning) {
 185                                 warning << string_compose(_("Session and LTC framerate mismatch: LTC:%1 Session:%2."),
 186                                                 Timecode::timecode_format_name(tc_format),
 187                                                 Timecode::timecode_format_name(cur_timecode))
 188                                         << endmsg;
 189                                 printed_timecode_warning = true;
 190                         }
 191                 }
 192                 ltc_timecode = tc_format;
 193                 a3e_timecode = cur_timecode;
 194         }
 195         return false;
 196 }
 197
 198 void
 199 LTC_Slave::process_ltc(framepos_t const now)
 200 {
 201         LTCFrameExt frame;
 202         while (ltc_decoder_read(decoder, &frame)) {
 203                 SMPTETimecode stime;
 204
 205                 ltc_frame_to_time(&stime, &frame.ltc, 0);
 206                 timecode.negative  = false;
 207                 timecode.subframes  = 0;
 208
 209                 /* set timecode.rate and timecode.drop: */
 210                 if (detect_ltc_fps(stime.frame, (frame.ltc.dfbit)? true : false)) {
 211                         reset();
 212                         last_timestamp = 0;
 213                 }
 214
 215 #if 0 // Devel/Debug
 216                 fprintf(stdout, "LTC %02d:%02d:%02d%c%02d | %8lld %8lld%s\n",
 217                         stime.hours,
 218                         stime.mins,
 219                         stime.secs,
 220                         (frame.ltc.dfbit) ? '.' : ':',
 221                         stime.frame,
 222                         frame.off_start,
 223                         frame.off_end,
 224                         frame.reverse ? " R" : "  "
 225                         );
 226 #endif
 227
 228                 /* when a full LTC frame is decoded, the timecode the LTC frame
 229                  * is referring has just passed.
 230                  * So we send the _next_ timecode which
 231                  * is expected to start at the end of the current frame
 232                  */
 233                 int fps_i = ceil(timecode.rate);
 234                 if (!frame.reverse) {
 235                         ltc_frame_increment(&frame.ltc, fps_i , 0);
 236                         ltc_frame_to_time(&stime, &frame.ltc, 0);
 237                         transport_direction = 1;
 238                 } else {
 239                         ltc_frame_decrement(&frame.ltc, fps_i , 0);
 240                         int off = frame.off_end - frame.off_start;
 241                         frame.off_start += off;
 242                         frame.off_end += off;
 243                         transport_direction = -1;
 244                 }
 245
 246                 timecode.hours   = stime.hours;
 247                 timecode.minutes = stime.mins;
 248                 timecode.seconds = stime.secs;
 249                 timecode.frames  = stime.frame;
 250
 251                 /* map LTC timecode to session TC setting */
 252                 framepos_t ltc_frame; ///< audio-frame corresponding to LTC frame
 253                 Timecode::timecode_to_sample (timecode, ltc_frame, true, false,
 254                         double(session.frame_rate()),
 255                         session.config.get_subframes_per_frame(),
 256                         session.config.get_timecode_offset_negative(), session.config.get_timecode_offset()
 257                         );
 258
 259                 framepos_t cur_timestamp = frame.off_end + 1;
 260                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC F: %1 LF: %2  N: %3 L: %4\n", ltc_frame, last_ltc_frame, cur_timestamp, last_timestamp));
 261                 if (frame.off_end + 1 <= last_timestamp || last_timestamp == 0) {
 262                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC speed: UNCHANGED: %1\n", ltc_speed));
 263                 } else {
 264                         ltc_speed = double(ltc_frame - last_ltc_frame) / double(cur_timestamp - last_timestamp);
 265                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC speed: %1\n", ltc_speed));
 266                 }
 267
 268                 if (fabs(ltc_speed) > 10.0) {
 269                         ltc_speed = 0;
 270                 }
 271
 272                 last_timestamp = frame.off_end + 1;
 273                 last_ltc_frame = ltc_frame;
 274         } /* end foreach decoded LTC frame */
 275 }
 276
 277 void
 278 LTC_Slave::init_engine_dll (framepos_t pos, int32_t inc)
 279 {
 280         double omega = 2.0 * M_PI * double(inc) / double(session.frame_rate());
 281         b = 1.4142135623730950488 * omega;
 282         c = omega * omega;
 283
 284         e2 = double(ltc_speed * inc);
 285         t0 = double(pos);
 286         t1 = t0 + e2;
 287         DEBUG_TRACE (DEBUG::LTC, string_compose ("[re-]init Engine DLL %1 %2 %3\n", t0, t1, e2));
 288 }
 289
 290 /* main entry point from session_process.cc
 291  * called from jack_process callback context
 292  * so it is OK to use jack_port_get_buffer()
 293  */
 294 bool
 295 LTC_Slave::speed_and_position (double& speed, framepos_t& pos)
 296 {
 297         bool engine_init_called = false;
 298         framepos_t now = session.engine().frame_time_at_cycle_start();
 299         framepos_t sess_pos = session.transport_frame(); // corresponds to now
 300         framecnt_t nframes = session.engine().frames_per_cycle();
 301
 302         jack_default_audio_sample_t *in;
 303         jack_latency_range_t ltc_latency;
 304
 305         boost::shared_ptr<Port> ltcport = session.engine().ltc_input_port();
 306         ltcport->get_connected_latency_range(ltc_latency, false);
 307         in = (jack_default_audio_sample_t*) jack_port_get_buffer (ltcport->jack_port(), nframes);
 308
 309         frameoffset_t skip = now - (monotonic_cnt + nframes);
 310         monotonic_cnt = now;
 311         DEBUG_TRACE (DEBUG::LTC, string_compose ("speed_and_position - TID:%1 | latency: %2 | skip %3\n", ::pthread_self(), ltc_latency.max, skip));
 312
 313         if (last_timestamp == 0) {
 314                 engine_dll_initstate = 0;
 315                 delayedlocked++;
 316         }
 317         else if (engine_dll_initstate != transport_direction && ltc_speed != 0) {
 318                 engine_dll_initstate = transport_direction;
 319                 init_engine_dll(last_ltc_frame + rint(ltc_speed * double(2 * nframes + now - last_timestamp)),
 320                                 session.engine().frames_per_cycle());
 321                 engine_init_called = true;
 322         }
 323
 324         if (in) {
 325                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC Process eng-tme: %1 eng-pos: %2\n", now, sess_pos));
 326                 /* when the jack-graph changes and if ardour performs
 327                  * locates, the audioengine is stopped (skipping frames) while
 328                  * jack [time] moves along.
 329                  */
 330                 if (skip > 0) {
 331                         DEBUG_TRACE (DEBUG::LTC, string_compose("engine skipped %1 frames. Feeding silence to LTC parser.\n", skip));
 332                         if (skip >= 8192) skip = 8192;
 333                         unsigned char sound[8192];
 334                         memset(sound, 0, sizeof(char) * skip);
 335                         ltc_decoder_write(decoder, sound, nframes, now);
 336                 } else if (skip != 0) {
 337                         /* this should never happen. it may if monotonic_cnt, now overflow on 64bit */
 338                         DEBUG_TRACE (DEBUG::LTC, string_compose("engine skipped %1 frames\n", skip));
 339                         reset();
 340                 }
 341
 342                 parse_ltc(nframes, in, now + ltc_latency.max );
 343                 process_ltc(now);
 344         }
 345
 346         if (last_timestamp == 0) {
 347                 DEBUG_TRACE (DEBUG::LTC, "last timestamp == 0\n");
 348                 speed = 0;
 349                 pos = session.transport_frame();
 350                 return true;
 351         } else if (ltc_speed != 0) {
 352                 delayedlocked = 0;
 353         }
 354
 355         if (abs(now - last_timestamp) > FLYWHEEL_TIMEOUT) {
 356                 DEBUG_TRACE (DEBUG::LTC, "flywheel timeout\n");
 357                 reset();
 358                 speed = 0;
 359                 pos = session.transport_frame();
 360                 return true;
 361         }
 362
 363         /* it take 2 cycles from naught to rolling.
 364          * during these to initial cycles the speed == 0
 365          *
 366          * the first cycle:
 367          * DEBUG::Slave: slave stopped, move to NNN
 368          * DEBUG::Transport: Request forced locate to NNN
 369          * DEBUG::Slave: slave state 0 @ NNN speed 0 cur delta VERY-LARGE-DELTA avg delta 1800
 370          * DEBUG::Slave: silent motion
 371          * DEBUG::Transport: realtime stop @ NNN
 372          * DEBUG::Transport: Butler transport work, todo = PostTransportStop,PostTransportLocate,PostTransportClearSubstate
 373          *
 374          * [engine skips frames to locate, jack time keeps rolling on]
 375          *
 376          * the second cycle:
 377          *
 378          * DEBUG::LTC: [re-]init Engine DLL
 379          * DEBUG::Slave: slave stopped, move to NNN+
 380          * ...
 381          *
 382          * we need to seek two cycles ahead: 2 * nframes
 383          */
 384         if (engine_dll_initstate == 0) {
 385                 DEBUG_TRACE (DEBUG::LTC, "engine DLL not initialized. ltc_speed\n");
 386                 speed = 0;
 387                 pos = last_ltc_frame + rint(ltc_speed * double(2 * nframes + now - last_timestamp));
 388                 return true;
 389         }
 390
 391         /* interpolate position according to speed and time since last LTC-frame*/
 392         double speed_flt = ltc_speed;
 393         double elapsed = (now - last_timestamp) * speed_flt;
 394
 395         if (!engine_init_called) {
 396                 const double e = elapsed + double (last_ltc_frame - sess_pos);
 397                 t0 = t1;
 398                 t1 += b * e + e2;
 399                 e2 += c * e;
 400                 speed_flt = (t1 - t0) / double(session.engine().frames_per_cycle());
 401                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC engine DLL t0:%1 t1:%2 err:%3 spd:%4 ddt:%5\n", t0, t1, e, speed_flt, e2 - session.engine().frames_per_cycle() ));
 402         } else {
 403                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC adjusting elapsed (no DLL) from %1 by %2\n", elapsed, (2 * nframes * ltc_speed)));
 404                 speed_flt = 0;
 405                 elapsed += 2.0 * nframes * ltc_speed; /* see note above */
 406         }
 407
 408         pos = last_ltc_frame + rint(elapsed);
 409         speed = speed_flt;
 410         current_delta = (pos - sess_pos);
 411
 412         if (((pos < 0) || (labs(current_delta) > 2 * session.frame_rate()))) {
 413                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC large drift: %1\n", current_delta));
 414                 reset();
 415                 speed = 0;
 416                 pos = session.transport_frame();
 417                 return true;
 418         }
 419
 420         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTCsync spd: %1 pos: %2 | last-pos: %3 elapsed: %4 delta: %5\n",
 421                                                  speed, pos, last_ltc_frame, elapsed, current_delta));
 422
 423 #if 1 /* provide a .1% deadzone to lock the speed */
 424         if (fabs(speed - 1.0) <= 0.001)
 425                 speed = 1.0;
 426 #endif
 427
 428         return true;
 429 }
 430
 431 Timecode::TimecodeFormat
 432 LTC_Slave::apparent_timecode_format () const
 433 {
 434         if      (timecode.rate == 24 && !timecode.drop)
 435                 return timecode_24;
 436         else if (timecode.rate == 25 && !timecode.drop)
 437                 return timecode_25;
 438         else if (rint(timecode.rate * 100) == 2997 && !timecode.drop)
 439                 return timecode_2997;
 440         else if (rint(timecode.rate * 100) == 2997 &&  timecode.drop)
 441                 return timecode_2997drop;
 442         else if (timecode.rate == 30 &&  timecode.drop)
 443                 return timecode_2997drop; // timecode_30drop; // LTC counting to 30 frames w/DF *means* 29.97 df
 444         else if (timecode.rate == 30 && !timecode.drop)
 445                 return timecode_30;
 446
 447         /* XXX - unknown timecode format */
 448         return session.config.get_timecode_format();
 449 }
 450
 451 std::string
 452 LTC_Slave::approximate_current_position() const
 453 {
 454         if (last_timestamp == 0) {
 455                 return " --:--:--:--";
 456         }
 457         return Timecode::timecode_format_time(timecode);
 458 }
 459
 460 std::string
 461 LTC_Slave::approximate_current_delta() const
 462 {
 463         char delta[24];
 464         if (last_timestamp == 0 || engine_dll_initstate == 0) {
 465                 snprintf(delta, sizeof(delta), "\u2012\u2012\u2012\u2012");
 466         } else if ((monotonic_cnt - last_timestamp) > 2 * frames_per_ltc_frame) {
 467                 snprintf(delta, sizeof(delta), "flywheel");
 468         } else {
 469                 snprintf(delta, sizeof(delta), "%s%4" PRIi64 " sm",
 470                                 PLUSMINUS(-current_delta), abs(current_delta));
 471         }
 472         return std::string(delta);
 473 }