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