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 ( 3 * 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(); // XXX at most 30fps ?
  48         timecode.rate = session.timecode_frames_per_second();
  49         timecode.drop  = session.timecode_drop_frames();
  50
  51         ltc_transport_pos = 0;
  52         did_reset_tc_format = false;
  53         delayedlocked = 10;
  54         engine_dll_initstate = 0;
  55         monotonic_cnt = 0;
  56
  57         memset(&prev_ltc_frame, 0, sizeof(LTCFrame));
  58
  59         ltc_timecode = timecode_60; // track changes of LTC timecode
  60         a3e_timecode = timecode_60; // track canges of Ardour's timecode
  61         printed_timecode_warning = false;
  62
  63         decoder = ltc_decoder_create((int) frames_per_ltc_frame, 128 /*queue size*/);
  64         reset();
  65         //session.engine().Xrun.connect_same_thread (*this, boost::bind (&LTC_Slave::reset, this));
  66 }
  67
  68 LTC_Slave::~LTC_Slave()
  69 {
  70         if (did_reset_tc_format) {
  71                 session.config.set_timecode_format (saved_tc_format);
  72         }
  73
  74         ltc_decoder_free(decoder);
  75 }
  76
  77 bool
  78 LTC_Slave::give_slave_full_control_over_transport_speed() const
  79 {
  80         return true; // DLL align to engine transport
  81         // return false; // for Session-level computed varispeed
  82 }
  83
  84 ARDOUR::framecnt_t
  85 LTC_Slave::resolution () const
  86 {
  87         return (framecnt_t) (frames_per_ltc_frame);
  88 }
  89
  90 ARDOUR::framecnt_t
  91 LTC_Slave::seekahead_distance () const
  92 {
  93         return 0;
  94 }
  95
  96 bool
  97 LTC_Slave::locked () const
  98 {
  99         return (delayedlocked < 5);
 100 }
 101
 102 bool
 103 LTC_Slave::ok() const
 104 {
 105         return true;
 106 }
 107
 108 void
 109 LTC_Slave::reset()
 110 {
 111         DEBUG_TRACE (DEBUG::LTC, "LTC reset()\n");
 112         frames_in_sequence = 0;
 113         ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
 114         last_timestamp = 0;
 115         current_delta = 0;
 116         transport_direction = 0;
 117         ltc_speed = 0;
 118         ltc_decoder_queue_flush(decoder);
 119 }
 120
 121 int
 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) return 1;
 127
 128         for (i = 0; i < nframes; i++) {
 129                 const int snd=(int)rint((127.0*in[i])+128.0);
 130                 sound[i] = (unsigned char) (snd&0xff);
 131         }
 132         ltc_decoder_write(decoder, sound, nframes, posinfo);
 133         return 0;
 134 }
 135
 136 bool
 137 LTC_Slave::detect_ltc_fps(int frameno, bool df)
 138 {
 139         double detected_fps = 0;
 140         if (frameno > ltc_detect_fps_max)
 141         {
 142                 ltc_detect_fps_max = frameno;
 143         }
 144         ltc_detect_fps_cnt++;
 145         if (ltc_detect_fps_cnt > 60)
 146         {
 147                 if (ltc_detect_fps_cnt > ltc_detect_fps_max
 148                     && (   ceil(timecode.rate) != (ltc_detect_fps_max + 1)
 149                         || timecode.drop != df
 150                         )
 151                     )
 152                 {
 153                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC detected FPS %1%2",
 154                                         ltc_detect_fps_max + 1, timecode.drop ? "df" : ""));
 155                         detected_fps = ltc_detect_fps_max + 1;
 156                         if (df) {
 157                                 /* LTC df -> indicates fractional framerate */
 158                                 detected_fps = detected_fps * 1000.0 / 1001.0;
 159                         }
 160                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC detected FPS: %1%2\n", detected_fps, df?"df":"ndf"));
 161                 }
 162                 ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
 163         }
 164
 165         /* when changed */
 166         if (detected_fps != 0 && (detected_fps != timecode.rate || df != timecode.drop)) {
 167                 timecode.rate = detected_fps;
 168                 timecode.drop = df;
 169                 frames_per_ltc_frame = double(session.frame_rate()) / timecode.rate;
 170                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC reset to FPS: %1%2 ; audio-frames per LTC: %3\n",
 171                                 detected_fps, df?"df":"ndf", frames_per_ltc_frame));
 172                 return true; // reset()
 173         }
 174
 175         /* poll and check session TC */
 176         if (1) {
 177                 TimecodeFormat tc_format = apparent_timecode_format();
 178                 TimecodeFormat cur_timecode = session.config.get_timecode_format();
 179                 if (Config->get_timecode_sync_frame_rate()) {
 180                         /* enforce time-code */
 181                         if (!did_reset_tc_format) {
 182                                 saved_tc_format = cur_timecode;
 183                                 did_reset_tc_format = true;
 184                         }
 185                         if (cur_timecode != tc_format) {
 186                                 warning << string_compose(_("Session framerate adjusted from %1 TO: LTC's %2."),
 187                                                 Timecode::timecode_format_name(cur_timecode),
 188                                                 Timecode::timecode_format_name(tc_format))
 189                                         << endmsg;
 190                         }
 191                         session.config.set_timecode_format (tc_format);
 192                 } else {
 193                         /* only warn about TC mismatch */
 194                         if (ltc_timecode != tc_format) printed_timecode_warning = false;
 195                         if (a3e_timecode != cur_timecode) printed_timecode_warning = false;
 196
 197                         if (cur_timecode != tc_format && ! printed_timecode_warning) {
 198                                 warning << string_compose(_("Session and LTC framerate mismatch: LTC:%1 Session:%2."),
 199                                                 Timecode::timecode_format_name(tc_format),
 200                                                 Timecode::timecode_format_name(cur_timecode))
 201                                         << endmsg;
 202                                 printed_timecode_warning = true;
 203                         }
 204                 }
 205                 ltc_timecode = tc_format;
 206                 a3e_timecode = cur_timecode;
 207         }
 208         return false;
 209 }
 210
 211 bool
 212 LTC_Slave::detect_ltc_discontinuity(LTCFrameExt *frame) {
 213         bool discontinuity_detected = false;
 214         /* detect discontinuities */
 215         if (frame->reverse) {
 216                 ltc_frame_decrement(&prev_ltc_frame, ceil(timecode.rate), 0);
 217         } else {
 218                 ltc_frame_increment(&prev_ltc_frame, ceil(timecode.rate), 0);
 219         }
 220
 221         if (memcmp(&prev_ltc_frame, &frame->ltc, sizeof(LTCFrame))) {
 222                 discontinuity_detected = true;
 223         }
 224         memcpy(&prev_ltc_frame, &frame->ltc, sizeof(LTCFrame));
 225
 226         /* notfify about discontinuities */
 227         if (frames_in_sequence > 0 && discontinuity_detected) {
 228                 DEBUG_TRACE (DEBUG::LTC, "# LTC DISCONTINUITY\n");
 229                 frames_in_sequence=0;
 230                 return true;
 231         }
 232         frames_in_sequence++;
 233
 234         return false;
 235 }
 236
 237 bool
 238 LTC_Slave::process_ltc(framepos_t const now, framepos_t const sess_pos, framecnt_t const nframes)
 239 {
 240         bool have_frame = false;
 241         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC Process eng-tme: %1 eng-pos: %2\n", now, sess_pos));
 242
 243         LTCFrameExt frame;
 244         while (ltc_decoder_read(decoder,&frame)) {
 245                 bool reinitialize_ltc_dll = false;
 246                 SMPTETimecode stime;
 247
 248                 ltc_frame_to_time(&stime, &frame.ltc, 0);
 249                 timecode.negative  = false;
 250                 timecode.subframes  = 0;
 251                 /* set timecode.rate and timecode.drop: */
 252                 if (detect_ltc_fps(stime.frame, (frame.ltc.dfbit)? true : false)) {
 253                         reset();
 254                         break;
 255                 }
 256                 if (detect_ltc_discontinuity(&frame)) {
 257                         ltc_discontinuity = true;
 258                 }
 259
 260 #if 0 // Devel/Debug
 261                 fprintf(stdout, "LTC %02d:%02d:%02d%c%02d | %8lld %8lld%s\n",
 262                         stime.hours,
 263                         stime.mins,
 264                         stime.secs,
 265                         (frame.ltc.dfbit) ? '.' : ':',
 266                         stime.frame,
 267                         frame.off_start,
 268                         frame.off_end,
 269                         frame.reverse ? " R" : "  "
 270                         );
 271
 272                 if (frames_in_sequence < 1) {
 273                         fprintf(stdout, " ####### FIRST LTC FRAME in SEQ #######\n");
 274                 }
 275
 276                 if (ltc_discontinuity) {
 277                         fprintf(stdout, " ####### LTC DISCONTINUITY #######\n");
 278                 }
 279 #endif
 280
 281                 if (frames_in_sequence < 1) {
 282                         continue;
 283                 }
 284
 285                 /* when a full LTC frame is decoded, the timecode the LTC frame
 286                  * is referring has just passed.
 287                  * So we send the _next_ timecode which
 288                  * is expected to start at the end of the current frame
 289                  */
 290                 int fps_i = ceil(timecode.rate);
 291                 if (!frame.reverse) {
 292                         ltc_frame_increment(&frame.ltc, fps_i , 0);
 293                         ltc_frame_to_time(&stime, &frame.ltc, 0);
 294                 } else {
 295                         ltc_frame_decrement(&frame.ltc, fps_i , 0);
 296                         int off = frame.off_end - frame.off_start;
 297                         frame.off_start += off;
 298                         frame.off_end += off;
 299                 }
 300
 301                 timecode.hours   = stime.hours;
 302                 timecode.minutes = stime.mins;
 303                 timecode.seconds = stime.secs;
 304                 timecode.frames  = stime.frame;
 305
 306                 /* map LTC timecode to session TC setting */
 307                 framepos_t ltc_frame; ///< audio-frame corresponding to LTC frame
 308                 Timecode::timecode_to_sample (timecode, ltc_frame, true, false,
 309                         double(session.frame_rate()),
 310                         session.config.get_subframes_per_frame(),
 311                         session.config.get_timecode_offset_negative(), session.config.get_timecode_offset()
 312                         );
 313
 314                 /* (frame.off_end + 1) = start of next LTC frame */
 315                 double poff = (frame.off_end + 1 - now);
 316                 ltc_transport_pos = ltc_frame - poff;
 317
 318 #if 0 // vari-speed LTC, no DLL
 319                         frames_per_ltc_frame = 1 + frame.off_end - frame.off_start;
 320 #else
 321                         frames_per_ltc_frame = (double(session.frame_rate()) / timecode.rate);
 322 #endif
 323
 324                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC frame: %1 poff: %2 pos: %3\n", ltc_frame, poff, ltc_transport_pos));
 325
 326                 if (ltc_discontinuity) {
 327                         ltc_discontinuity=false;
 328                         if (ltc_speed==0
 329                                         || !locked()
 330                                         || (ltc_transport_pos - sess_pos) > FLYWHEEL_TIMEOUT)
 331                         {
 332                                 engine_dll_initstate = 0;
 333                                 reset();
 334                         }
 335                         reinitialize_ltc_dll = true;
 336                 }
 337
 338                 if (last_timestamp == 0
 339                         || ((now - last_timestamp) > FLYWHEEL_TIMEOUT)
 340                         || (abs(current_delta) >  FLYWHEEL_TIMEOUT) // TODO LTC-delta not engine delta
 341                         || (frame.reverse && transport_direction != -1)
 342                         || (!frame.reverse && transport_direction != 1)
 343                         ) {
 344                         reinitialize_ltc_dll = true;
 345                         engine_dll_initstate = 0;
 346                         reset();
 347                 }
 348
 349                 if (reinitialize_ltc_dll) {
 350                         init_ltc_dll(ltc_transport_pos, frames_per_ltc_frame);
 351
 352                         if (ltc_speed==0 || !locked()) {
 353                                 if (frame.reverse) {
 354                                         transport_direction = -1;
 355                                         ltc_transport_pos -= nframes * rint((2 * frames_per_ltc_frame + poff)/nframes);
 356                                 } else {
 357                                         transport_direction = 1;
 358                                         ltc_transport_pos += nframes * rint((2 * frames_per_ltc_frame + poff)/nframes);
 359                                 }
 360                         }
 361
 362                 } else {
 363                         // update DLL
 364                         double e = (double(ltc_frame) - poff - double(sess_pos));
 365                         t0 = t1;
 366                         t1 += b * e + e2;
 367                         e2 += c * e;
 368
 369                         ltc_speed = (t1 - t0) / frames_per_ltc_frame;
 370                         current_delta = (ltc_transport_pos - sess_pos);
 371                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC DLL t0:%1 t1:%2 err:%3 spd:%4 ddt:%5\n", t0, t1, e, ltc_speed, e2 - frames_per_ltc_frame));
 372
 373                 }
 374
 375                 /* the are equivalent
 376                  * TODO: choose the value with larger diff ->
 377                  * minimize roundig errors when extrapolating
 378                  */
 379 #if 1
 380                 last_timestamp = now;
 381                 last_ltc_frame = ltc_transport_pos;
 382 #else
 383                 last_timestamp = frame.off_end + 1;
 384                 last_ltc_frame = ltc_frame;
 385 #endif
 386
 387                 have_frame = true;
 388         } /* end foreach decoded LTC frame */
 389
 390         return have_frame;
 391 }
 392
 393 void
 394 LTC_Slave::init_ltc_dll(framepos_t const tme, double const dt)
 395 {
 396         omega = 2.0 * M_PI * dt / double(session.frame_rate());
 397         b = 1.4142135623730950488 * omega;
 398         c = omega * omega;
 399
 400         e2 = dt;
 401         t0 = double(tme);
 402         t1 = t0 + e2;
 403         DEBUG_TRACE (DEBUG::LTC, string_compose ("[re-]init LTC DLL %1 %2 %3\n", t0, t1, e2));
 404 }
 405
 406 void
 407 LTC_Slave::init_engine_dll (framepos_t pos, framepos_t inc)
 408 {
 409         /* the bandwidth of the DLL is a trade-off,
 410          * because the max-speed of the transport in ardour is
 411          * limited to +-8.0, a larger bandwidth would cause oscillations
 412          *
 413          * But this is only really a problem if the user performs manual
 414          * seeks while transport is running and slaved to LTC.
 415          */
 416         oe = 2.0 * M_PI * double(inc/2.0) / double(session.frame_rate());
 417         be = 1.4142135623730950488 * oe;
 418         ce = oe * oe;
 419
 420         ee2 = double(transport_direction * inc);
 421         te0 = double(pos);
 422         te1 = te0 + ee2;
 423         DEBUG_TRACE (DEBUG::LTC, string_compose ("[re-]init Engine DLL %1 %2 %3\n", te0, te1, ee2));
 424 }
 425
 426 /* main entry point from session_process.cc
 427  * called from jack_process callback context
 428  * so it is OK to use jack_port_get_buffer() etc
 429  */
 430 bool
 431 LTC_Slave::speed_and_position (double& speed, framepos_t& pos)
 432 {
 433         //framepos_t now = session.engine().frame_time_at_cycle_start();
 434         //framepos_t now = session.engine().processed_frames();
 435         framepos_t now = monotonic_cnt;
 436         framepos_t sess_pos = session.transport_frame(); // corresponds to now
 437         framecnt_t nframes = session.engine().frames_per_cycle();
 438         jack_default_audio_sample_t *in;
 439         jack_latency_range_t ltc_latency;
 440
 441         monotonic_cnt += nframes;
 442
 443         boost::shared_ptr<Port> ltcport = session.engine().ltc_input_port();
 444         ltcport->get_connected_latency_range(ltc_latency, false);
 445         in = (jack_default_audio_sample_t*) jack_port_get_buffer (ltcport->jack_port(), nframes);
 446
 447         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC_Slave::speed_and_position - TID:%1 | latency: %2\n", ::pthread_self(), ltc_latency.max));
 448
 449         if (last_timestamp == 0) {
 450                 engine_dll_initstate = 0;
 451                 delayedlocked++;
 452         }
 453         else if (engine_dll_initstate != transport_direction) {
 454                 engine_dll_initstate = transport_direction;
 455                 init_engine_dll(last_ltc_frame, session.engine().frames_per_cycle());
 456         }
 457
 458         if (in) {
 459                 parse_ltc(nframes, in, now  + ltc_latency.max );
 460                 if (!process_ltc(now, sess_pos, nframes) && ltc_speed != 0) {
 461                 }
 462         }
 463
 464         /* interpolate position according to speed and time since last LTC-frame*/
 465         double speed_flt = ltc_speed;
 466         framecnt_t elapsed;
 467         if (speed_flt == 0.0f) {
 468                 elapsed = 0;
 469         } else {
 470                 /* scale elapsed time by the current LTC speed */
 471                 if (last_timestamp && (now > last_timestamp)) {
 472                         elapsed = (now - last_timestamp) * speed_flt;
 473                 } else {
 474                         elapsed = 0;
 475                 }
 476                 /* update engine DLL and calculate speed */
 477                 const double e = double (last_ltc_frame + elapsed - sess_pos);
 478                 te0 = te1;
 479                 te1 += be * e + ee2;
 480                 ee2 += ce * e;
 481                 speed_flt = (te1 - te0) / double(session.engine().frames_per_cycle());
 482                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC engine DLL t0:%1 t1:%2 err:%3 spd:%4 ddt:%5\n", te0, te1, e, speed_flt, ee2 - session.engine().frames_per_cycle() ));
 483         }
 484
 485         pos = last_ltc_frame + elapsed;
 486         speed = speed_flt;
 487         current_delta = (pos - sess_pos);
 488
 489         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTCsync spd: %1 pos: %2 | last-pos: %3 elapsed: %4 delta: %5\n",
 490                                                  speed, pos, last_ltc_frame, elapsed, current_delta));
 491
 492         if (last_timestamp != 0 /* && frames_in_sequence > 8*/) {
 493                 delayedlocked = 0;
 494         }
 495
 496         if (last_timestamp == 0 || ((now - last_timestamp) > FLYWHEEL_TIMEOUT)) {
 497                 DEBUG_TRACE (DEBUG::LTC, "LTC no-signal - reset\n");
 498                 reset();
 499                 engine_dll_initstate = 0;
 500                 speed = 0;
 501                 pos = session.transport_frame();
 502                 return true;
 503         }
 504
 505         if (last_timestamp != 0  && ltc_speed != 0 && ((ltc_transport_pos < 0) || (labs(current_delta) > 10 * session.frame_rate()))) {
 506                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC large drift. %1\n", current_delta));
 507                 // XXX only re-init engine DLL ?
 508                 reset();
 509                 engine_dll_initstate = 0;
 510                 speed = 0;
 511                 pos = session.transport_frame();
 512                 return true;
 513         }
 514
 515 #if 1
 516         /* provide a 1% deadzone to lock the speed */
 517         if (fabs(speed - 1.0) <= 0.01)
 518                 speed = 1.0;
 519 #endif
 520
 521         return true;
 522 }
 523
 524 Timecode::TimecodeFormat
 525 LTC_Slave::apparent_timecode_format () const
 526 {
 527         if      (timecode.rate == 24 && !timecode.drop)
 528                 return timecode_24;
 529         else if (timecode.rate == 25 && !timecode.drop)
 530                 return timecode_25;
 531         else if (rint(timecode.rate * 100) == 2997 && !timecode.drop)
 532                 return timecode_2997;
 533         else if (rint(timecode.rate * 100) == 2997 &&  timecode.drop)
 534                 return timecode_2997drop;
 535         else if (timecode.rate == 30 &&  timecode.drop)
 536                 return timecode_2997drop; // timecode_30drop; // LTC counting to 30 frames w/DF *means* 29.97 df
 537         else if (timecode.rate == 30 && !timecode.drop)
 538                 return timecode_30;
 539
 540         /* XXX - unknown timecode format */
 541         return session.config.get_timecode_format();
 542 }
 543
 544 std::string
 545 LTC_Slave::approximate_current_position() const
 546 {
 547         if (last_timestamp == 0) {
 548                 return " --:--:--:--";
 549         }
 550         return Timecode::timecode_format_time(timecode);
 551 }
 552
 553 std::string
 554 LTC_Slave::approximate_current_delta() const
 555 {
 556         char delta[24];
 557         if (last_timestamp == 0 || frames_in_sequence < 2) {
 558                 snprintf(delta, sizeof(delta), "\u2012\u2012\u2012\u2012");
 559         } else if ((monotonic_cnt - last_timestamp) > 2 * frames_per_ltc_frame) {
 560                 snprintf(delta, sizeof(delta), "flywheel");
 561         } else {
 562                 // TODO if current_delta > 1 frame -> display timecode.
 563                 // delta >0 if A3's transport is _behind_ LTC
 564                 snprintf(delta, sizeof(delta), "%s%4" PRIi64 " sm",
 565                                 PLUSMINUS(-current_delta), abs(current_delta));
 566         }
 567         return std::string(delta);
 568 }