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 = timecode_60; // track changes of LTC fps
  57         a3e_timecode = timecode_60; // track changes of Ardour's fps
  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         session.Xrun.connect_same_thread (port_connections, boost::bind (&LTC_Slave::resync_latency, this));
  65         session.engine().GraphReordered.connect_same_thread (port_connections, boost::bind (&LTC_Slave::resync_latency, this));
  66 }
  67
  68 LTC_Slave::~LTC_Slave()
  69 {
  70         port_connections.drop_connections();
  71
  72         if (did_reset_tc_format) {
  73                 session.config.set_timecode_format (saved_tc_format);
  74         }
  75
  76         ltc_decoder_free(decoder);
  77 }
  78
  79 ARDOUR::framecnt_t
  80 LTC_Slave::resolution () const
  81 {
  82         return (framecnt_t) (frames_per_ltc_frame);
  83 }
  84
  85 bool
  86 LTC_Slave::locked () const
  87 {
  88         return (delayedlocked < 5);
  89 }
  90
  91 bool
  92 LTC_Slave::ok() const
  93 {
  94         return true;
  95 }
  96
  97 void
  98 LTC_Slave::resync_latency()
  99 {
 100         DEBUG_TRACE (DEBUG::LTC, "LTC resync()\n");
 101         engine_dll_initstate = 0;
 102
 103         if (session.ltc_output_io()) { /* check if Port exits */
 104                 boost::shared_ptr<Port> ltcport = session.ltc_input_port();
 105                 ltcport->get_connected_latency_range(ltc_slave_latency, false);
 106         }
 107 }
 108
 109 void
 110 LTC_Slave::reset()
 111 {
 112         DEBUG_TRACE (DEBUG::LTC, "LTC reset()\n");
 113         last_timestamp = 0;
 114         current_delta = 0;
 115         transport_direction = 0;
 116         ltc_speed = 0;
 117         engine_dll_initstate = 0;
 118         resync_latency();
 119 }
 120
 121 void
 122 LTC_Slave::parse_ltc(const jack_nframes_t nframes, const jack_default_audio_sample_t * const in, const framecnt_t posinfo)
 123 {
 124         jack_nframes_t i;
 125         unsigned char sound[8192];
 126         if (nframes > 8192) {
 127                 /* TODO warn once or wrap, loop conversion below
 128                  * does jack/A3 support > 8192 spp anyway?
 129                  */
 130                 return;
 131         }
 132
 133         for (i = 0; i < nframes; i++) {
 134                 const int snd=(int)rint((127.0*in[i])+128.0);
 135                 sound[i] = (unsigned char) (snd&0xff);
 136         }
 137         ltc_decoder_write(decoder, sound, nframes, posinfo);
 138         return;
 139 }
 140
 141 bool
 142 LTC_Slave::equal_ltc_frame_time(LTCFrame *a, LTCFrame *b) {
 143         if (       a->frame_units != b->frame_units
 144                 || a->frame_tens  != b->frame_tens
 145                 || a->dfbit       != b->dfbit
 146                 || a->secs_units  != b->secs_units
 147                 || a->secs_tens   != b->secs_tens
 148                 || a->mins_units  != b->mins_units
 149                 || a->mins_tens   != b->mins_tens
 150                 || a->hours_units != b->hours_units
 151                 || a->hours_tens  != b->hours_tens
 152              ) {
 153                 return false;
 154         }
 155         return true;
 156 }
 157
 158 bool
 159 LTC_Slave::detect_discontinuity(LTCFrameExt *frame, int fps, bool fuzzy) {
 160         bool discontinuity_detected = false;
 161
 162         if (fuzzy && (
 163                   ( frame->reverse && prev_frame.ltc.frame_units == 0)
 164                 ||(!frame->reverse && frame->ltc.frame_units == 0)
 165                 )) {
 166                 memcpy(&prev_frame, frame, sizeof(LTCFrameExt));
 167                 return false;
 168         }
 169
 170         if (frame->reverse) {
 171                 ltc_frame_decrement(&prev_frame.ltc, fps , 0);
 172         } else {
 173                 ltc_frame_increment(&prev_frame.ltc, fps , 0);
 174         }
 175         if (!equal_ltc_frame_time(&prev_frame.ltc, &frame->ltc)) {
 176                 discontinuity_detected = true;
 177         }
 178
 179     memcpy(&prev_frame, frame, sizeof(LTCFrameExt));
 180     return discontinuity_detected;
 181 }
 182
 183 bool
 184 LTC_Slave::detect_ltc_fps(int frameno, bool df)
 185 {
 186         bool fps_changed = false;
 187         double detected_fps = 0;
 188         if (frameno > ltc_detect_fps_max)
 189         {
 190                 ltc_detect_fps_max = frameno;
 191         }
 192         ltc_detect_fps_cnt++;
 193
 194         if (ltc_detect_fps_cnt > 40)
 195         {
 196                 if (ltc_detect_fps_cnt > ltc_detect_fps_max
 197                     && (   ceil(timecode.rate) != (ltc_detect_fps_max + 1)
 198                         || timecode.drop != df
 199                         )
 200                     )
 201                 {
 202                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC detected FPS %1%2",
 203                                         ltc_detect_fps_max + 1, timecode.drop ? "df" : ""));
 204                         detected_fps = ltc_detect_fps_max + 1;
 205                         if (df) {
 206                                 /* LTC df -> indicates fractional framerate */
 207                                 detected_fps = detected_fps * 1000.0 / 1001.0;
 208                         }
 209                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC detected FPS: %1%2\n", detected_fps, df?"df":"ndf"));
 210                 }
 211                 ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
 212         }
 213
 214         /* when changed */
 215         if (detected_fps != 0 && (detected_fps != timecode.rate || df != timecode.drop)) {
 216                 timecode.rate = detected_fps;
 217                 timecode.drop = df;
 218                 frames_per_ltc_frame = double(session.frame_rate()) / timecode.rate;
 219                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC reset to FPS: %1%2 ; audio-frames per LTC: %3\n",
 220                                 detected_fps, df?"df":"ndf", frames_per_ltc_frame));
 221                 fps_changed=true;
 222         }
 223
 224         /* poll and check session TC */
 225         TimecodeFormat tc_format = apparent_timecode_format();
 226         TimecodeFormat cur_timecode = session.config.get_timecode_format();
 227         if (Config->get_timecode_sync_frame_rate()) {
 228                 /* enforce time-code */
 229                 if (!did_reset_tc_format) {
 230                         saved_tc_format = cur_timecode;
 231                         did_reset_tc_format = true;
 232                 }
 233                 if (cur_timecode != tc_format) {
 234                         warning << string_compose(_("Session framerate adjusted from %1 to LTC's %2."),
 235                                         Timecode::timecode_format_name(cur_timecode),
 236                                         Timecode::timecode_format_name(tc_format))
 237                                 << endmsg;
 238                         session.config.set_timecode_format (tc_format);
 239                 }
 240         } else {
 241                 /* only warn about TC mismatch */
 242                 if (ltc_timecode != tc_format) printed_timecode_warning = false;
 243                 if (a3e_timecode != cur_timecode) printed_timecode_warning = false;
 244
 245                 if (cur_timecode != tc_format && ! printed_timecode_warning) {
 246                         warning << string_compose(_("Session and LTC framerate mismatch: LTC:%1 Session:%2."),
 247                                         Timecode::timecode_format_name(tc_format),
 248                                         Timecode::timecode_format_name(cur_timecode))
 249                                 << endmsg;
 250                         printed_timecode_warning = true;
 251                 }
 252         }
 253         ltc_timecode = tc_format;
 254         a3e_timecode = cur_timecode;
 255
 256         return fps_changed;
 257 }
 258
 259 void
 260 LTC_Slave::process_ltc(framepos_t const now)
 261 {
 262         LTCFrameExt frame;
 263         while (ltc_decoder_read(decoder, &frame)) {
 264                 SMPTETimecode stime;
 265
 266                 ltc_frame_to_time(&stime, &frame.ltc, 0);
 267                 timecode.negative  = false;
 268                 timecode.subframes  = 0;
 269
 270                 /* set timecode.rate and timecode.drop: */
 271                 bool ltc_is_static = equal_ltc_frame_time(&prev_frame.ltc, &frame.ltc);
 272
 273                 if (detect_discontinuity(&frame, ceil(timecode.rate), !fps_detected)) {
 274                         if (fps_detected) { ltc_detect_fps_cnt = ltc_detect_fps_max = 0; }
 275                         fps_detected=false;
 276                 }
 277
 278                 if (!ltc_is_static && detect_ltc_fps(stime.frame, (frame.ltc.dfbit)? true : false)) {
 279                         reset();
 280                         fps_detected=true;
 281                 }
 282
 283 #if 0 // Devel/Debug
 284                 fprintf(stdout, "LTC %02d:%02d:%02d%c%02d | %8lld %8lld%s\n",
 285                         stime.hours,
 286                         stime.mins,
 287                         stime.secs,
 288                         (frame.ltc.dfbit) ? '.' : ':',
 289                         stime.frame,
 290                         frame.off_start,
 291                         frame.off_end,
 292                         frame.reverse ? " R" : "  "
 293                         );
 294 #endif
 295
 296                 /* when a full LTC frame is decoded, the timecode the LTC frame
 297                  * is referring has just passed.
 298                  * So we send the _next_ timecode which
 299                  * is expected to start at the end of the current frame
 300                  */
 301                 int fps_i = ceil(timecode.rate);
 302                 if (!frame.reverse) {
 303                         ltc_frame_increment(&frame.ltc, fps_i , 0);
 304                         ltc_frame_to_time(&stime, &frame.ltc, 0);
 305                         transport_direction = 1;
 306                 } else {
 307                         ltc_frame_decrement(&frame.ltc, fps_i , 0);
 308                         int off = frame.off_end - frame.off_start;
 309                         frame.off_start += off;
 310                         frame.off_end += off;
 311                         transport_direction = -1;
 312                 }
 313
 314                 timecode.hours   = stime.hours;
 315                 timecode.minutes = stime.mins;
 316                 timecode.seconds = stime.secs;
 317                 timecode.frames  = stime.frame;
 318
 319                 /* map LTC timecode to session TC setting */
 320                 framepos_t ltc_frame; ///< audio-frame corresponding to LTC frame
 321                 Timecode::timecode_to_sample (timecode, ltc_frame, true, false,
 322                         double(session.frame_rate()),
 323                         session.config.get_subframes_per_frame(),
 324                         session.config.get_timecode_offset_negative(), session.config.get_timecode_offset()
 325                         );
 326
 327                 framepos_t cur_timestamp = frame.off_end + 1;
 328                 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));
 329                 if (frame.off_end + 1 <= last_timestamp || last_timestamp == 0) {
 330                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC speed: UNCHANGED: %1\n", ltc_speed));
 331                 } else {
 332                         ltc_speed = double(ltc_frame - last_ltc_frame) / double(cur_timestamp - last_timestamp);
 333                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC speed: %1\n", ltc_speed));
 334                 }
 335
 336                 if (fabs(ltc_speed) > 10.0) {
 337                         ltc_speed = 0;
 338                 }
 339
 340                 last_timestamp = frame.off_end + 1;
 341                 last_ltc_frame = ltc_frame;
 342         } /* end foreach decoded LTC frame */
 343 }
 344
 345 void
 346 LTC_Slave::init_engine_dll (framepos_t pos, int32_t inc)
 347 {
 348         double omega = 2.0 * M_PI * double(inc) / double(session.frame_rate());
 349         b = 1.4142135623730950488 * omega;
 350         c = omega * omega;
 351
 352         e2 = double(ltc_speed * inc);
 353         t0 = double(pos);
 354         t1 = t0 + e2;
 355         DEBUG_TRACE (DEBUG::LTC, string_compose ("[re-]init Engine DLL %1 %2 %3\n", t0, t1, e2));
 356 }
 357
 358 /* main entry point from session_process.cc
 359  * called from jack_process callback context
 360  * so it is OK to use jack_port_get_buffer()
 361  */
 362 bool
 363 LTC_Slave::speed_and_position (double& speed, framepos_t& pos)
 364 {
 365         bool engine_init_called = false;
 366         framepos_t now = session.engine().frame_time_at_cycle_start();
 367         framepos_t sess_pos = session.transport_frame(); // corresponds to now
 368         framecnt_t nframes = session.engine().frames_per_cycle();
 369
 370         jack_default_audio_sample_t *in;
 371
 372         boost::shared_ptr<Port> ltcport = session.ltc_input_port();
 373
 374 #if 1
 375         /* TODO read layency only on demand -> ::reset()
 376          * this is already prepared.
 377          *
 378          * ..but first fix jack2 issue with re-computing latency
 379          * in the correct order. Until then, querying it in the
 380          * process-callback is the only way to get the current value
 381          */
 382         ltcport->get_connected_latency_range(ltc_slave_latency, false);
 383 #endif
 384         in = (jack_default_audio_sample_t*) jack_port_get_buffer (ltcport->jack_port(), nframes);
 385
 386         frameoffset_t skip = now - (monotonic_cnt + nframes);
 387         monotonic_cnt = now;
 388         DEBUG_TRACE (DEBUG::LTC, string_compose ("speed_and_position - TID:%1 | latency: %2 | skip %3\n", ::pthread_self(), ltc_slave_latency.max, skip));
 389
 390         if (last_timestamp == 0) {
 391                 engine_dll_initstate = 0;
 392                 delayedlocked++;
 393         }
 394         else if (engine_dll_initstate != transport_direction && ltc_speed != 0) {
 395                 engine_dll_initstate = transport_direction;
 396                 init_engine_dll(last_ltc_frame + rint(ltc_speed * double(2 * nframes + now - last_timestamp)),
 397                                 session.engine().frames_per_cycle());
 398                 engine_init_called = true;
 399         }
 400
 401         if (in) {
 402                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC Process eng-tme: %1 eng-pos: %2\n", now, sess_pos));
 403                 /* when the jack-graph changes and if ardour performs
 404                  * locates, the audioengine is stopped (skipping frames) while
 405                  * jack [time] moves along.
 406                  */
 407                 if (skip > 0) {
 408                         DEBUG_TRACE (DEBUG::LTC, string_compose("engine skipped %1 frames. Feeding silence to LTC parser.\n", skip));
 409                         if (skip >= 8192) skip = 8192;
 410                         unsigned char sound[8192];
 411                         memset(sound, 0, sizeof(char) * skip);
 412                         ltc_decoder_write(decoder, sound, nframes, now);
 413                 } else if (skip != 0) {
 414                         /* this should never happen. it may if monotonic_cnt, now overflow on 64bit */
 415                         DEBUG_TRACE (DEBUG::LTC, string_compose("engine skipped %1 frames\n", skip));
 416                         reset();
 417                 }
 418
 419                 parse_ltc(nframes, in, now + ltc_slave_latency.max );
 420                 process_ltc(now);
 421         }
 422
 423         if (last_timestamp == 0) {
 424                 DEBUG_TRACE (DEBUG::LTC, "last timestamp == 0\n");
 425                 speed = 0;
 426                 pos = session.transport_frame();
 427                 return true;
 428         } else if (ltc_speed != 0) {
 429                 delayedlocked = 0;
 430         }
 431
 432         if (abs(now - last_timestamp) > FLYWHEEL_TIMEOUT) {
 433                 DEBUG_TRACE (DEBUG::LTC, "flywheel timeout\n");
 434                 reset();
 435                 speed = 0;
 436                 pos = session.transport_frame();
 437                 return true;
 438         }
 439
 440         /* it take 2 cycles from naught to rolling.
 441          * during these to initial cycles the speed == 0
 442          *
 443          * the first cycle:
 444          * DEBUG::Slave: slave stopped, move to NNN
 445          * DEBUG::Transport: Request forced locate to NNN
 446          * DEBUG::Slave: slave state 0 @ NNN speed 0 cur delta VERY-LARGE-DELTA avg delta 1800
 447          * DEBUG::Slave: silent motion
 448          * DEBUG::Transport: realtime stop @ NNN
 449          * DEBUG::Transport: Butler transport work, todo = PostTransportStop,PostTransportLocate,PostTransportClearSubstate
 450          *
 451          * [engine skips frames to locate, jack time keeps rolling on]
 452          *
 453          * the second cycle:
 454          *
 455          * DEBUG::LTC: [re-]init Engine DLL
 456          * DEBUG::Slave: slave stopped, move to NNN+
 457          * ...
 458          *
 459          * we need to seek two cycles ahead: 2 * nframes
 460          */
 461         if (engine_dll_initstate == 0) {
 462                 DEBUG_TRACE (DEBUG::LTC, "engine DLL not initialized. ltc_speed\n");
 463                 speed = 0;
 464                 pos = last_ltc_frame + rint(ltc_speed * double(2 * nframes + now - last_timestamp));
 465                 return true;
 466         }
 467
 468         /* interpolate position according to speed and time since last LTC-frame*/
 469         double speed_flt = ltc_speed;
 470         double elapsed = (now - last_timestamp) * speed_flt;
 471
 472         if (!engine_init_called) {
 473                 const double e = elapsed + double (last_ltc_frame - sess_pos);
 474                 t0 = t1;
 475                 t1 += b * e + e2;
 476                 e2 += c * e;
 477                 speed_flt = (t1 - t0) / double(session.engine().frames_per_cycle());
 478                 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() ));
 479         } else {
 480                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC adjusting elapsed (no DLL) from %1 by %2\n", elapsed, (2 * nframes * ltc_speed)));
 481                 speed_flt = 0;
 482                 elapsed += 2.0 * nframes * ltc_speed; /* see note above */
 483         }
 484
 485         pos = last_ltc_frame + rint(elapsed);
 486         speed = speed_flt;
 487         current_delta = (pos - sess_pos);
 488
 489         if (((pos < 0) || (labs(current_delta) > 2 * session.frame_rate()))) {
 490                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC large drift: %1\n", current_delta));
 491                 reset();
 492                 speed = 0;
 493                 pos = session.transport_frame();
 494                 return true;
 495         }
 496
 497         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTCsync spd: %1 pos: %2 | last-pos: %3 elapsed: %4 delta: %5\n",
 498                                                  speed, pos, last_ltc_frame, elapsed, current_delta));
 499
 500 #if 1 /* provide a .1% deadzone to lock the speed */
 501         if (fabs(speed - 1.0) <= 0.001)
 502                 speed = 1.0;
 503 #endif
 504
 505         return true;
 506 }
 507
 508 Timecode::TimecodeFormat
 509 LTC_Slave::apparent_timecode_format () const
 510 {
 511         if      (timecode.rate == 24 && !timecode.drop)
 512                 return timecode_24;
 513         else if (timecode.rate == 25 && !timecode.drop)
 514                 return timecode_25;
 515         else if (rint(timecode.rate * 100) == 2997 && !timecode.drop)
 516                 return timecode_2997;
 517         else if (rint(timecode.rate * 100) == 2997 &&  timecode.drop)
 518                 return timecode_2997drop;
 519         else if (timecode.rate == 30 &&  timecode.drop)
 520                 return timecode_2997drop; // timecode_30drop; // LTC counting to 30 frames w/DF *means* 29.97 df
 521         else if (timecode.rate == 30 && !timecode.drop)
 522                 return timecode_30;
 523
 524         /* XXX - unknown timecode format */
 525         return session.config.get_timecode_format();
 526 }
 527
 528 std::string
 529 LTC_Slave::approximate_current_position() const
 530 {
 531         if (last_timestamp == 0) {
 532                 return " --:--:--:--";
 533         }
 534         return Timecode::timecode_format_time(timecode);
 535 }
 536
 537 std::string
 538 LTC_Slave::approximate_current_delta() const
 539 {
 540         char delta[24];
 541         if (last_timestamp == 0 || engine_dll_initstate == 0) {
 542                 snprintf(delta, sizeof(delta), "\u2012\u2012\u2012\u2012");
 543         } else if ((monotonic_cnt - last_timestamp) > 2 * frames_per_ltc_frame) {
 544                 snprintf(delta, sizeof(delta), "flywheel");
 545         } else {
 546                 snprintf(delta, sizeof(delta), "%s%4" PRIi64 " sm",
 547                                 PLUSMINUS(-current_delta), abs(current_delta));
 548         }
 549         return std::string(delta);
 550 }