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         {
 203                 if (ltc_detect_fps_cnt > ltc_detect_fps_max
 204                     && (   ceil(timecode.rate) != (ltc_detect_fps_max + 1)
 205                         || timecode.drop != df
 206                         )
 207                     )
 208                 {
 209                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC detected FPS %1%2",
 210                                         ltc_detect_fps_max + 1, timecode.drop ? "df" : ""));
 211                         detected_fps = ltc_detect_fps_max + 1;
 212                         if (df) {
 213                                 /* LTC df -> indicates fractional framerate */
 214                                 detected_fps = detected_fps * 1000.0 / 1001.0;
 215                         }
 216                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC detected FPS: %1%2\n", detected_fps, df?"df":"ndf"));
 217                 }
 218                 ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
 219         }
 220
 221         /* when changed */
 222         if (detected_fps != 0 && (detected_fps != timecode.rate || df != timecode.drop)) {
 223                 timecode.rate = detected_fps;
 224                 timecode.drop = df;
 225                 frames_per_ltc_frame = double(session.frame_rate()) / timecode.rate;
 226                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC reset to FPS: %1%2 ; audio-frames per LTC: %3\n",
 227                                 detected_fps, df?"df":"ndf", frames_per_ltc_frame));
 228                 fps_changed=true;
 229         }
 230
 231         /* poll and check session TC */
 232         TimecodeFormat tc_format = apparent_timecode_format();
 233         TimecodeFormat cur_timecode = session.config.get_timecode_format();
 234
 235         if (Config->get_timecode_source_2997() && tc_format == Timecode::timecode_2997drop) {
 236                 tc_format = Timecode::timecode_2997000drop;
 237         }
 238         else
 239         if (Config->get_timecode_source_2997() && tc_format == Timecode::timecode_2997) {
 240                 tc_format = Timecode::timecode_2997000;
 241         }
 242
 243         if (Config->get_timecode_sync_frame_rate()) {
 244                 /* enforce time-code */
 245                 if (!did_reset_tc_format) {
 246                         saved_tc_format = cur_timecode;
 247                         did_reset_tc_format = true;
 248                 }
 249                 if (cur_timecode != tc_format) {
 250                         warning << string_compose(_("Session framerate adjusted from %1 to LTC's %2."),
 251                                         Timecode::timecode_format_name(cur_timecode),
 252                                         Timecode::timecode_format_name(tc_format))
 253                                 << endmsg;
 254                         session.config.set_timecode_format (tc_format);
 255                 }
 256         } else {
 257                 /* only warn about TC mismatch */
 258                 if (ltc_timecode != tc_format) printed_timecode_warning = false;
 259                 if (a3e_timecode != cur_timecode) printed_timecode_warning = false;
 260
 261                 if (cur_timecode != tc_format && ! printed_timecode_warning) {
 262                         warning << string_compose(_("Session and LTC framerate mismatch: LTC:%1 Session:%2."),
 263                                         Timecode::timecode_format_name(tc_format),
 264                                         Timecode::timecode_format_name(cur_timecode))
 265                                 << endmsg;
 266                         printed_timecode_warning = true;
 267                 }
 268         }
 269         ltc_timecode = tc_format;
 270         a3e_timecode = cur_timecode;
 271
 272         return fps_changed;
 273 }
 274
 275 void
 276 LTC_Slave::process_ltc(framepos_t const now)
 277 {
 278         LTCFrameExt frame;
 279         while (ltc_decoder_read(decoder, &frame)) {
 280                 SMPTETimecode stime;
 281
 282                 ltc_frame_to_time(&stime, &frame.ltc, 0);
 283                 timecode.negative  = false;
 284                 timecode.subframes  = 0;
 285
 286                 /* set timecode.rate and timecode.drop: */
 287                 bool ltc_is_static = equal_ltc_frame_time(&prev_frame.ltc, &frame.ltc);
 288
 289                 if (detect_discontinuity(&frame, ceil(timecode.rate), !fps_detected)) {
 290                         if (fps_detected) { ltc_detect_fps_cnt = ltc_detect_fps_max = 0; }
 291                         fps_detected=false;
 292                 }
 293
 294                 if (!ltc_is_static && detect_ltc_fps(stime.frame, (frame.ltc.dfbit)? true : false)) {
 295                         reset();
 296                         fps_detected=true;
 297                 }
 298
 299 #if 0 // Devel/Debug
 300                 fprintf(stdout, "LTC %02d:%02d:%02d%c%02d | %8lld %8lld%s\n",
 301                         stime.hours,
 302                         stime.mins,
 303                         stime.secs,
 304                         (frame.ltc.dfbit) ? '.' : ':',
 305                         stime.frame,
 306                         frame.off_start,
 307                         frame.off_end,
 308                         frame.reverse ? " R" : "  "
 309                         );
 310 #endif
 311
 312                 /* when a full LTC frame is decoded, the timecode the LTC frame
 313                  * is referring has just passed.
 314                  * So we send the _next_ timecode which
 315                  * is expected to start at the end of the current frame
 316                  */
 317                 int fps_i = ceil(timecode.rate);
 318                 if (!frame.reverse) {
 319                         ltc_frame_increment(&frame.ltc, fps_i , 0);
 320                         ltc_frame_to_time(&stime, &frame.ltc, 0);
 321                         transport_direction = 1;
 322                 } else {
 323                         ltc_frame_decrement(&frame.ltc, fps_i , 0);
 324                         int off = frame.off_end - frame.off_start;
 325                         frame.off_start += off;
 326                         frame.off_end += off;
 327                         transport_direction = -1;
 328                 }
 329
 330                 timecode.hours   = stime.hours;
 331                 timecode.minutes = stime.mins;
 332                 timecode.seconds = stime.secs;
 333                 timecode.frames  = stime.frame;
 334
 335                 /* map LTC timecode to session TC setting */
 336                 framepos_t ltc_frame; ///< audio-frame corresponding to LTC frame
 337                 Timecode::timecode_to_sample (timecode, ltc_frame, true, false,
 338                         double(session.frame_rate()),
 339                         session.config.get_subframes_per_frame(),
 340                         session.config.get_timecode_offset_negative(), session.config.get_timecode_offset()
 341                         );
 342
 343                 framepos_t cur_timestamp = frame.off_end + 1;
 344                 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));
 345                 if (frame.off_end + 1 <= last_timestamp || last_timestamp == 0) {
 346                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC speed: UNCHANGED: %1\n", ltc_speed));
 347                 } else {
 348                         ltc_speed = double(ltc_frame - last_ltc_frame) / double(cur_timestamp - last_timestamp);
 349                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC speed: %1\n", ltc_speed));
 350                 }
 351
 352                 if (fabs(ltc_speed) > 10.0) {
 353                         ltc_speed = 0;
 354                 }
 355
 356                 last_timestamp = frame.off_end + 1;
 357                 last_ltc_frame = ltc_frame;
 358         } /* end foreach decoded LTC frame */
 359 }
 360
 361 void
 362 LTC_Slave::init_engine_dll (framepos_t pos, int32_t inc)
 363 {
 364         double omega = 2.0 * M_PI * double(inc) / double(session.frame_rate());
 365         b = 1.4142135623730950488 * omega;
 366         c = omega * omega;
 367
 368         e2 = double(ltc_speed * inc);
 369         t0 = double(pos);
 370         t1 = t0 + e2;
 371         DEBUG_TRACE (DEBUG::LTC, string_compose ("[re-]init Engine DLL %1 %2 %3\n", t0, t1, e2));
 372 }
 373
 374 /* main entry point from session_process.cc
 375  * called from jack_process callback context
 376  * so it is OK to use jack_port_get_buffer()
 377  */
 378 bool
 379 LTC_Slave::speed_and_position (double& speed, framepos_t& pos)
 380 {
 381         bool engine_init_called = false;
 382         framepos_t now = session.engine().frame_time_at_cycle_start();
 383         framepos_t sess_pos = session.transport_frame(); // corresponds to now
 384         framecnt_t nframes = session.engine().frames_per_cycle();
 385
 386         jack_default_audio_sample_t *in;
 387
 388         boost::shared_ptr<Port> ltcport = session.ltc_input_port();
 389
 390         in = (jack_default_audio_sample_t*) jack_port_get_buffer (ltcport->jack_port(), nframes);
 391
 392         frameoffset_t skip = now - (monotonic_cnt + nframes);
 393         monotonic_cnt = now;
 394         DEBUG_TRACE (DEBUG::LTC, string_compose ("speed_and_position - TID:%1 | latency: %2 | skip %3\n", ::pthread_self(), ltc_slave_latency.max, skip));
 395
 396         if (last_timestamp == 0) {
 397                 engine_dll_initstate = 0;
 398                 delayedlocked++;
 399         }
 400         else if (engine_dll_initstate != transport_direction && ltc_speed != 0) {
 401                 engine_dll_initstate = transport_direction;
 402                 init_engine_dll(last_ltc_frame + rint(ltc_speed * double(2 * nframes + now - last_timestamp)),
 403                                 session.engine().frames_per_cycle());
 404                 engine_init_called = true;
 405         }
 406
 407         if (in) {
 408                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC Process eng-tme: %1 eng-pos: %2\n", now, sess_pos));
 409                 /* when the jack-graph changes and if ardour performs
 410                  * locates, the audioengine is stopped (skipping frames) while
 411                  * jack [time] moves along.
 412                  */
 413                 if (skip > 0) {
 414                         DEBUG_TRACE (DEBUG::LTC, string_compose("engine skipped %1 frames. Feeding silence to LTC parser.\n", skip));
 415                         if (skip >= 8192) skip = 8192;
 416                         unsigned char sound[8192];
 417                         memset(sound, 0, sizeof(char) * skip);
 418                         ltc_decoder_write(decoder, sound, nframes, now);
 419                 } else if (skip != 0) {
 420                         /* this should never happen. it may if monotonic_cnt, now overflow on 64bit */
 421                         DEBUG_TRACE (DEBUG::LTC, string_compose("engine skipped %1 frames\n", skip));
 422                         reset();
 423                 }
 424
 425                 parse_ltc(nframes, in, now - ltc_slave_latency.max );
 426                 process_ltc(now);
 427         }
 428
 429         if (last_timestamp == 0) {
 430                 DEBUG_TRACE (DEBUG::LTC, "last timestamp == 0\n");
 431                 speed = 0;
 432                 pos = session.transport_frame();
 433                 return true;
 434         } else if (ltc_speed != 0) {
 435                 delayedlocked = 0;
 436         }
 437
 438         if (abs(now - last_timestamp) > FLYWHEEL_TIMEOUT) {
 439                 DEBUG_TRACE (DEBUG::LTC, "flywheel timeout\n");
 440                 reset();
 441                 speed = 0;
 442                 pos = session.transport_frame();
 443                 return true;
 444         }
 445
 446         /* it take 2 cycles from naught to rolling.
 447          * during these to initial cycles the speed == 0
 448          *
 449          * the first cycle:
 450          * DEBUG::Slave: slave stopped, move to NNN
 451          * DEBUG::Transport: Request forced locate to NNN
 452          * DEBUG::Slave: slave state 0 @ NNN speed 0 cur delta VERY-LARGE-DELTA avg delta 1800
 453          * DEBUG::Slave: silent motion
 454          * DEBUG::Transport: realtime stop @ NNN
 455          * DEBUG::Transport: Butler transport work, todo = PostTransportStop,PostTransportLocate,PostTransportClearSubstate
 456          *
 457          * [engine skips frames to locate, jack time keeps rolling on]
 458          *
 459          * the second cycle:
 460          *
 461          * DEBUG::LTC: [re-]init Engine DLL
 462          * DEBUG::Slave: slave stopped, move to NNN+
 463          * ...
 464          *
 465          * we need to seek two cycles ahead: 2 * nframes
 466          */
 467         if (engine_dll_initstate == 0) {
 468                 DEBUG_TRACE (DEBUG::LTC, "engine DLL not initialized. ltc_speed\n");
 469                 speed = 0;
 470                 pos = last_ltc_frame + rint(ltc_speed * double(2 * nframes + now - last_timestamp));
 471                 return true;
 472         }
 473
 474         /* interpolate position according to speed and time since last LTC-frame*/
 475         double speed_flt = ltc_speed;
 476         double elapsed = (now - last_timestamp) * speed_flt;
 477
 478         if (!engine_init_called) {
 479                 const double e = elapsed + double (last_ltc_frame - sess_pos);
 480                 t0 = t1;
 481                 t1 += b * e + e2;
 482                 e2 += c * e;
 483                 speed_flt = (t1 - t0) / double(session.engine().frames_per_cycle());
 484                 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() ));
 485         } else {
 486                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC adjusting elapsed (no DLL) from %1 by %2\n", elapsed, (2 * nframes * ltc_speed)));
 487                 speed_flt = 0;
 488                 elapsed += 2.0 * nframes * ltc_speed; /* see note above */
 489         }
 490
 491         pos = last_ltc_frame + rint(elapsed);
 492         speed = speed_flt;
 493         current_delta = (pos - sess_pos);
 494
 495         if (((pos < 0) || (labs(current_delta) > 2 * session.frame_rate()))) {
 496                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC large drift: %1\n", current_delta));
 497                 reset();
 498                 speed = 0;
 499                 pos = session.transport_frame();
 500                 return true;
 501         }
 502
 503         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTCsync spd: %1 pos: %2 | last-pos: %3 elapsed: %4 delta: %5\n",
 504                                                  speed, pos, last_ltc_frame, elapsed, current_delta));
 505
 506         /* provide a .1% deadzone to lock the speed */
 507         if (fabs(speed - 1.0) <= 0.001) {
 508                 speed = 1.0;
 509         }
 510
 511         return true;
 512 }
 513
 514 Timecode::TimecodeFormat
 515 LTC_Slave::apparent_timecode_format () const
 516 {
 517         if      (timecode.rate == 24 && !timecode.drop)
 518                 return timecode_24;
 519         else if (timecode.rate == 25 && !timecode.drop)
 520                 return timecode_25;
 521         else if (rint(timecode.rate * 100) == 2997 && !timecode.drop)
 522                 return timecode_2997;
 523         else if (rint(timecode.rate * 100) == 2997 &&  timecode.drop)
 524                 return timecode_2997drop;
 525         else if (timecode.rate == 30 &&  timecode.drop)
 526                 return timecode_2997drop; // timecode_30drop; // LTC counting to 30 frames w/DF *means* 29.97 df
 527         else if (timecode.rate == 30 && !timecode.drop)
 528                 return timecode_30;
 529
 530         /* XXX - unknown timecode format */
 531         return session.config.get_timecode_format();
 532 }
 533
 534 std::string
 535 LTC_Slave::approximate_current_position() const
 536 {
 537         if (last_timestamp == 0) {
 538                 return " --:--:--:--";
 539         }
 540         return Timecode::timecode_format_time(timecode);
 541 }
 542
 543 std::string
 544 LTC_Slave::approximate_current_delta() const
 545 {
 546         char delta[24];
 547         if (last_timestamp == 0 || engine_dll_initstate == 0) {
 548                 snprintf(delta, sizeof(delta), "\u2012\u2012\u2012\u2012");
 549         } else if ((monotonic_cnt - last_timestamp) > 2 * frames_per_ltc_frame) {
 550                 snprintf(delta, sizeof(delta), "flywheel");
 551         } else {
 552                 snprintf(delta, sizeof(delta), "%s%4" PRIi64 " sm",
 553                                 PLUSMINUS(-current_delta), abs(current_delta));
 554         }
 555         return std::string(delta);
 556 }