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         fps_detected=false;
  55
  56         ltc_timecode = session.config.get_timecode_format();
  57         a3e_timecode = session.config.get_timecode_format();
  58         printed_timecode_warning = false;
  59         ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
  60         memset(&prev_frame, 0, sizeof(LTCFrameExt));
  61
  62         decoder = ltc_decoder_create((int) frames_per_ltc_frame, 128 /*queue size*/);
  63         reset();
  64         resync_latency();
  65         session.Xrun.connect_same_thread (port_connections, boost::bind (&LTC_Slave::resync_xrun, this));
  66         session.engine().GraphReordered.connect_same_thread (port_connections, boost::bind (&LTC_Slave::resync_latency, this));
  67 }
  68
  69 LTC_Slave::~LTC_Slave()
  70 {
  71         port_connections.drop_connections();
  72
  73         if (did_reset_tc_format) {
  74                 session.config.set_timecode_format (saved_tc_format);
  75         }
  76
  77         ltc_decoder_free(decoder);
  78 }
  79
  80 ARDOUR::framecnt_t
  81 LTC_Slave::resolution () const
  82 {
  83         return (framecnt_t) (session.frame_rate() / 1000);
  84 }
  85
  86 bool
  87 LTC_Slave::locked () const
  88 {
  89         return (delayedlocked < 5);
  90 }
  91
  92 bool
  93 LTC_Slave::ok() const
  94 {
  95         return true;
  96 }
  97
  98 void
  99 LTC_Slave::resync_xrun()
 100 {
 101         DEBUG_TRACE (DEBUG::LTC, "LTC resync_xrun()\n");
 102         engine_dll_initstate = 0;
 103 }
 104
 105 void
 106 LTC_Slave::resync_latency()
 107 {
 108         DEBUG_TRACE (DEBUG::LTC, "LTC resync_latency()\n");
 109         engine_dll_initstate = 0;
 110
 111         if (!session.deletion_in_progress() && session.ltc_output_io()) { /* check if Port exits */
 112                 boost::shared_ptr<Port> ltcport = session.ltc_input_port();
 113                 ltcport->get_connected_latency_range(ltc_slave_latency, false);
 114         }
 115 }
 116
 117 void
 118 LTC_Slave::reset()
 119 {
 120         DEBUG_TRACE (DEBUG::LTC, "LTC reset()\n");
 121         last_timestamp = 0;
 122         current_delta = 0;
 123         transport_direction = 0;
 124         ltc_speed = 0;
 125         engine_dll_initstate = 0;
 126 }
 127
 128 void
 129 LTC_Slave::parse_ltc(const jack_nframes_t nframes, const jack_default_audio_sample_t * const in, const framecnt_t posinfo)
 130 {
 131         jack_nframes_t i;
 132         unsigned char sound[8192];
 133         if (nframes > 8192) {
 134                 /* TODO warn once or wrap, loop conversion below
 135                  * does jack/A3 support > 8192 spp anyway?
 136                  */
 137                 return;
 138         }
 139
 140         for (i = 0; i < nframes; i++) {
 141                 const int snd=(int)rint((127.0*in[i])+128.0);
 142                 sound[i] = (unsigned char) (snd&0xff);
 143         }
 144         ltc_decoder_write(decoder, sound, nframes, posinfo);
 145         return;
 146 }
 147
 148 bool
 149 LTC_Slave::equal_ltc_frame_time(LTCFrame *a, LTCFrame *b) {
 150         if (       a->frame_units != b->frame_units
 151                 || a->frame_tens  != b->frame_tens
 152                 || a->dfbit       != b->dfbit
 153                 || a->secs_units  != b->secs_units
 154                 || a->secs_tens   != b->secs_tens
 155                 || a->mins_units  != b->mins_units
 156                 || a->mins_tens   != b->mins_tens
 157                 || a->hours_units != b->hours_units
 158                 || a->hours_tens  != b->hours_tens
 159              ) {
 160                 return false;
 161         }
 162         return true;
 163 }
 164
 165 bool
 166 LTC_Slave::detect_discontinuity(LTCFrameExt *frame, int fps, bool fuzzy) {
 167         bool discontinuity_detected = false;
 168
 169         if (fuzzy && (
 170                   ( frame->reverse && prev_frame.ltc.frame_units == 0)
 171                 ||(!frame->reverse && frame->ltc.frame_units == 0)
 172                 )) {
 173                 memcpy(&prev_frame, frame, sizeof(LTCFrameExt));
 174                 return false;
 175         }
 176
 177         if (frame->reverse) {
 178                 ltc_frame_decrement(&prev_frame.ltc, fps , 0);
 179         } else {
 180                 ltc_frame_increment(&prev_frame.ltc, fps , 0);
 181         }
 182         if (!equal_ltc_frame_time(&prev_frame.ltc, &frame->ltc)) {
 183                 discontinuity_detected = true;
 184         }
 185
 186     memcpy(&prev_frame, frame, sizeof(LTCFrameExt));
 187     return discontinuity_detected;
 188 }
 189
 190 bool
 191 LTC_Slave::detect_ltc_fps(int frameno, bool df)
 192 {
 193         bool fps_changed = false;
 194         double detected_fps = 0;
 195         if (frameno > ltc_detect_fps_max)
 196         {
 197                 ltc_detect_fps_max = frameno;
 198         }
 199         ltc_detect_fps_cnt++;
 200
 201         if (ltc_detect_fps_cnt > 40) {
 202                 if (ltc_detect_fps_cnt > ltc_detect_fps_max) {
 203                         detected_fps = ltc_detect_fps_max + 1;
 204                         if (df) {
 205                                 /* LTC df -> indicates fractional framerate */
 206                                 if (Config->get_timecode_source_2997()) {
 207                                         detected_fps = detected_fps * 999.0 / 1000.0;
 208                                 } else {
 209                                         detected_fps = detected_fps * 1000.0 / 1001.0;
 210                                 }
 211                         }
 212
 213                         if (timecode.rate != detected_fps || timecode.drop != df) {
 214                                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC detected FPS: %1%2\n", detected_fps, df?"df":"ndf"));
 215                         } else {
 216                                 detected_fps = 0; /* no cange */
 217                         }
 218                 }
 219                 ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
 220         }
 221
 222         /* when changed */
 223         if (detected_fps != 0 && (detected_fps != timecode.rate || df != timecode.drop)) {
 224                 timecode.rate = detected_fps;
 225                 timecode.drop = df;
 226                 frames_per_ltc_frame = double(session.frame_rate()) / timecode.rate;
 227                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC reset to FPS: %1%2 ; audio-frames per LTC: %3\n",
 228                                 detected_fps, df?"df":"ndf", frames_per_ltc_frame));
 229                 fps_changed=true;
 230         }
 231
 232         /* poll and check session TC */
 233         TimecodeFormat tc_format = apparent_timecode_format();
 234         TimecodeFormat cur_timecode = session.config.get_timecode_format();
 235
 236         if (Config->get_timecode_sync_frame_rate()) {
 237                 /* enforce time-code */
 238                 if (!did_reset_tc_format) {
 239                         saved_tc_format = cur_timecode;
 240                         did_reset_tc_format = true;
 241                 }
 242                 if (cur_timecode != tc_format) {
 243                         if (ceil(Timecode::timecode_to_frames_per_second(cur_timecode)) != ceil(Timecode::timecode_to_frames_per_second(tc_format))) {
 244                                 warning << string_compose(_("Session framerate adjusted from %1 to LTC's %2."),
 245                                                 Timecode::timecode_format_name(cur_timecode),
 246                                                 Timecode::timecode_format_name(tc_format))
 247                                         << endmsg;
 248                         }
 249                         session.config.set_timecode_format (tc_format);
 250                 }
 251         } else {
 252                 /* only warn about TC mismatch */
 253                 if (ltc_timecode != tc_format) printed_timecode_warning = false;
 254                 if (a3e_timecode != cur_timecode) printed_timecode_warning = false;
 255
 256                 if (cur_timecode != tc_format && ! printed_timecode_warning) {
 257                         if (ceil(Timecode::timecode_to_frames_per_second(cur_timecode)) != ceil(Timecode::timecode_to_frames_per_second(tc_format))) {
 258                                 warning << string_compose(_("Session and LTC framerate mismatch: LTC:%1 Session:%2."),
 259                                                 Timecode::timecode_format_name(tc_format),
 260                                                 Timecode::timecode_format_name(cur_timecode))
 261                                         << endmsg;
 262                         }
 263                         printed_timecode_warning = true;
 264                 }
 265         }
 266         ltc_timecode = tc_format;
 267         a3e_timecode = cur_timecode;
 268
 269         return fps_changed;
 270 }
 271
 272 void
 273 LTC_Slave::process_ltc(framepos_t const now)
 274 {
 275         LTCFrameExt frame;
 276         while (ltc_decoder_read(decoder, &frame)) {
 277                 SMPTETimecode stime;
 278
 279                 ltc_frame_to_time(&stime, &frame.ltc, 0);
 280                 timecode.negative  = false;
 281                 timecode.subframes  = 0;
 282
 283                 /* set timecode.rate and timecode.drop: */
 284                 bool ltc_is_static = equal_ltc_frame_time(&prev_frame.ltc, &frame.ltc);
 285
 286                 if (detect_discontinuity(&frame, ceil(timecode.rate), !fps_detected)) {
 287                         if (fps_detected) { ltc_detect_fps_cnt = ltc_detect_fps_max = 0; }
 288                         fps_detected=false;
 289                 }
 290
 291                 if (!ltc_is_static && detect_ltc_fps(stime.frame, (frame.ltc.dfbit)? true : false)) {
 292                         reset();
 293                         fps_detected=true;
 294                 }
 295
 296 #if 0 // Devel/Debug
 297                 fprintf(stdout, "LTC %02d:%02d:%02d%c%02d | %8lld %8lld%s\n",
 298                         stime.hours,
 299                         stime.mins,
 300                         stime.secs,
 301                         (frame.ltc.dfbit) ? '.' : ':',
 302                         stime.frame,
 303                         frame.off_start,
 304                         frame.off_end,
 305                         frame.reverse ? " R" : "  "
 306                         );
 307 #endif
 308
 309                 /* when a full LTC frame is decoded, the timecode the LTC frame
 310                  * is referring has just passed.
 311                  * So we send the _next_ timecode which
 312                  * is expected to start at the end of the current frame
 313                  */
 314                 int fps_i = ceil(timecode.rate);
 315                 if (!frame.reverse) {
 316                         ltc_frame_increment(&frame.ltc, fps_i , 0);
 317                         ltc_frame_to_time(&stime, &frame.ltc, 0);
 318                         transport_direction = 1;
 319                 } else {
 320                         ltc_frame_decrement(&frame.ltc, fps_i , 0);
 321                         int off = frame.off_end - frame.off_start;
 322                         frame.off_start += off;
 323                         frame.off_end += off;
 324                         transport_direction = -1;
 325                 }
 326
 327                 timecode.hours   = stime.hours;
 328                 timecode.minutes = stime.mins;
 329                 timecode.seconds = stime.secs;
 330                 timecode.frames  = stime.frame;
 331
 332                 /* map LTC timecode to session TC setting */
 333                 framepos_t ltc_frame; ///< audio-frame corresponding to LTC frame
 334                 Timecode::timecode_to_sample (timecode, ltc_frame, false, false,
 335                         double(session.frame_rate()),
 336                         session.config.get_subframes_per_frame(),
 337                         session.config.get_timecode_offset_negative(), session.config.get_timecode_offset()
 338                         );
 339
 340                 framepos_t cur_timestamp = frame.off_end + 1;
 341                 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));
 342                 if (frame.off_end + 1 <= last_timestamp || last_timestamp == 0) {
 343                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC speed: UNCHANGED: %1\n", ltc_speed));
 344                 } else {
 345                         ltc_speed = double(ltc_frame - last_ltc_frame) / double(cur_timestamp - last_timestamp);
 346                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC speed: %1\n", ltc_speed));
 347                 }
 348
 349                 if (fabs(ltc_speed) > 10.0) {
 350                         ltc_speed = 0;
 351                 }
 352
 353                 last_timestamp = frame.off_end + 1;
 354                 last_ltc_frame = ltc_frame;
 355         } /* end foreach decoded LTC frame */
 356 }
 357
 358 void
 359 LTC_Slave::init_engine_dll (framepos_t pos, int32_t inc)
 360 {
 361         double omega = 2.0 * M_PI * double(inc) / double(session.frame_rate());
 362         b = 1.4142135623730950488 * omega;
 363         c = omega * omega;
 364
 365         e2 = double(ltc_speed * inc);
 366         t0 = double(pos);
 367         t1 = t0 + e2;
 368         DEBUG_TRACE (DEBUG::LTC, string_compose ("[re-]init Engine DLL %1 %2 %3\n", t0, t1, e2));
 369 }
 370
 371 /* main entry point from session_process.cc
 372  * called from jack_process callback context
 373  * so it is OK to use jack_port_get_buffer()
 374  */
 375 bool
 376 LTC_Slave::speed_and_position (double& speed, framepos_t& pos)
 377 {
 378         bool engine_init_called = false;
 379         framepos_t now = session.engine().frame_time_at_cycle_start();
 380         framepos_t sess_pos = session.transport_frame(); // corresponds to now
 381         framecnt_t nframes = session.engine().frames_per_cycle();
 382
 383         jack_default_audio_sample_t *in;
 384
 385         boost::shared_ptr<Port> ltcport = session.ltc_input_port();
 386
 387         in = (jack_default_audio_sample_t*) jack_port_get_buffer (ltcport->jack_port(), nframes);
 388
 389         frameoffset_t skip = now - (monotonic_cnt + nframes);
 390         monotonic_cnt = now;
 391         DEBUG_TRACE (DEBUG::LTC, string_compose ("speed_and_position - TID:%1 | latency: %2 | skip %3\n", ::pthread_self(), ltc_slave_latency.max, skip));
 392
 393         if (last_timestamp == 0) {
 394                 engine_dll_initstate = 0;
 395                 delayedlocked++;
 396         }
 397         else if (engine_dll_initstate != transport_direction && ltc_speed != 0) {
 398                 engine_dll_initstate = transport_direction;
 399                 init_engine_dll(last_ltc_frame + rint(ltc_speed * double(2 * nframes + now - last_timestamp)),
 400                                 session.engine().frames_per_cycle());
 401                 engine_init_called = true;
 402         }
 403
 404         if (in) {
 405                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC Process eng-tme: %1 eng-pos: %2\n", now, sess_pos));
 406                 /* when the jack-graph changes and if ardour performs
 407                  * locates, the audioengine is stopped (skipping frames) while
 408                  * jack [time] moves along.
 409                  */
 410                 if (skip > 0) {
 411                         DEBUG_TRACE (DEBUG::LTC, string_compose("engine skipped %1 frames. Feeding silence to LTC parser.\n", skip));
 412                         if (skip >= 8192) skip = 8192;
 413                         unsigned char sound[8192];
 414                         memset(sound, 0, sizeof(char) * skip);
 415                         ltc_decoder_write(decoder, sound, nframes, now);
 416                 } else if (skip != 0) {
 417                         /* this should never happen. it may if monotonic_cnt, now overflow on 64bit */
 418                         DEBUG_TRACE (DEBUG::LTC, string_compose("engine skipped %1 frames\n", skip));
 419                         reset();
 420                 }
 421
 422                 parse_ltc(nframes, in, now - ltc_slave_latency.max );
 423                 process_ltc(now);
 424         }
 425
 426         if (last_timestamp == 0) {
 427                 DEBUG_TRACE (DEBUG::LTC, "last timestamp == 0\n");
 428                 speed = 0;
 429                 pos = session.transport_frame();
 430                 return true;
 431         } else if (ltc_speed != 0) {
 432                 delayedlocked = 0;
 433         }
 434
 435         if (abs(now - last_timestamp) > FLYWHEEL_TIMEOUT) {
 436                 DEBUG_TRACE (DEBUG::LTC, "flywheel timeout\n");
 437                 reset();
 438                 speed = 0;
 439                 pos = session.transport_frame();
 440                 return true;
 441         }
 442
 443         /* it take 2 cycles from naught to rolling.
 444          * during these to initial cycles the speed == 0
 445          *
 446          * the first cycle:
 447          * DEBUG::Slave: slave stopped, move to NNN
 448          * DEBUG::Transport: Request forced locate to NNN
 449          * DEBUG::Slave: slave state 0 @ NNN speed 0 cur delta VERY-LARGE-DELTA avg delta 1800
 450          * DEBUG::Slave: silent motion
 451          * DEBUG::Transport: realtime stop @ NNN
 452          * DEBUG::Transport: Butler transport work, todo = PostTransportStop,PostTransportLocate,PostTransportClearSubstate
 453          *
 454          * [engine skips frames to locate, jack time keeps rolling on]
 455          *
 456          * the second cycle:
 457          *
 458          * DEBUG::LTC: [re-]init Engine DLL
 459          * DEBUG::Slave: slave stopped, move to NNN+
 460          * ...
 461          *
 462          * we need to seek two cycles ahead: 2 * nframes
 463          */
 464         if (engine_dll_initstate == 0) {
 465                 DEBUG_TRACE (DEBUG::LTC, "engine DLL not initialized. ltc_speed\n");
 466                 speed = 0;
 467                 pos = last_ltc_frame + rint(ltc_speed * double(2 * nframes + now - last_timestamp));
 468                 return true;
 469         }
 470
 471         /* interpolate position according to speed and time since last LTC-frame*/
 472         double speed_flt = ltc_speed;
 473         double elapsed = (now - last_timestamp) * speed_flt;
 474
 475         if (!engine_init_called) {
 476                 const double e = elapsed + double (last_ltc_frame - sess_pos);
 477                 t0 = t1;
 478                 t1 += b * e + e2;
 479                 e2 += c * e;
 480                 speed_flt = (t1 - t0) / double(session.engine().frames_per_cycle());
 481                 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() ));
 482         } else {
 483                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC adjusting elapsed (no DLL) from %1 by %2\n", elapsed, (2 * nframes * ltc_speed)));
 484                 speed_flt = 0;
 485                 elapsed += 2.0 * nframes * ltc_speed; /* see note above */
 486         }
 487
 488         pos = last_ltc_frame + rint(elapsed);
 489         speed = speed_flt;
 490         current_delta = (pos - sess_pos);
 491
 492         if (((pos < 0) || (labs(current_delta) > 2 * session.frame_rate()))) {
 493                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC large drift: %1\n", current_delta));
 494                 reset();
 495                 speed = 0;
 496                 pos = session.transport_frame();
 497                 return true;
 498         }
 499
 500         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTCsync spd: %1 pos: %2 | last-pos: %3 elapsed: %4 delta: %5\n",
 501                                                  speed, pos, last_ltc_frame, elapsed, current_delta));
 502
 503         /* provide a .1% deadzone to lock the speed */
 504         if (fabs(speed - 1.0) <= 0.001) {
 505                 speed = 1.0;
 506         }
 507
 508         return true;
 509 }
 510
 511 Timecode::TimecodeFormat
 512 LTC_Slave::apparent_timecode_format () const
 513 {
 514         if      (timecode.rate == 24 && !timecode.drop)
 515                 return timecode_24;
 516         else if (timecode.rate == 25 && !timecode.drop)
 517                 return timecode_25;
 518         else if (rint(timecode.rate * 100) == 2997 && !timecode.drop)
 519                 return (Config->get_timecode_source_2997() ? timecode_2997000 : timecode_2997);
 520         else if (rint(timecode.rate * 100) == 2997 &&  timecode.drop)
 521                 return (Config->get_timecode_source_2997() ? timecode_2997000drop : timecode_2997drop);
 522         else if (timecode.rate == 30 &&  timecode.drop)
 523                 return timecode_2997drop; // timecode_30drop; // LTC counting to 30 frames w/DF *means* 29.97 df
 524         else if (timecode.rate == 30 && !timecode.drop)
 525                 return timecode_30;
 526
 527         /* XXX - unknown timecode format */
 528         return session.config.get_timecode_format();
 529 }
 530
 531 std::string
 532 LTC_Slave::approximate_current_position() const
 533 {
 534         if (last_timestamp == 0) {
 535                 return " \u2012\u2012:\u2012\u2012:\u2012\u2012:\u2012\u2012";
 536         }
 537         return Timecode::timecode_format_time(timecode);
 538 }
 539
 540 std::string
 541 LTC_Slave::approximate_current_delta() const
 542 {
 543         char delta[24];
 544         if (last_timestamp == 0 || engine_dll_initstate == 0) {
 545                 snprintf(delta, sizeof(delta), "\u2012\u2012\u2012\u2012");
 546         } else if ((monotonic_cnt - last_timestamp) > 2 * frames_per_ltc_frame) {
 547                 snprintf(delta, sizeof(delta), "flywheel");
 548         } else {
 549                 snprintf(delta, sizeof(delta), "%s%4" PRIi64 " sm",
 550                                 PLUSMINUS(-current_delta), abs(current_delta));
 551         }
 552         return std::string(delta);
 553 }