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
  55         ltc_timecode = timecode_60; // track changes of LTC fps
  56         a3e_timecode = timecode_60; // track changes of Ardour's fps
  57         printed_timecode_warning = false;
  58         ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
  59         memset(&prev_frame, 0, sizeof(LTCFrameExt));
  60
  61         decoder = ltc_decoder_create((int) frames_per_ltc_frame, 128 /*queue size*/);
  62         reset();
  63 }
  64
  65 LTC_Slave::~LTC_Slave()
  66 {
  67         if (did_reset_tc_format) {
  68                 session.config.set_timecode_format (saved_tc_format);
  69         }
  70
  71         ltc_decoder_free(decoder);
  72 }
  73
  74 ARDOUR::framecnt_t
  75 LTC_Slave::resolution () const
  76 {
  77         return (framecnt_t) (frames_per_ltc_frame);
  78 }
  79
  80 bool
  81 LTC_Slave::locked () const
  82 {
  83         return (delayedlocked < 5);
  84 }
  85
  86 bool
  87 LTC_Slave::ok() const
  88 {
  89         return true;
  90 }
  91
  92 void
  93 LTC_Slave::reset()
  94 {
  95         DEBUG_TRACE (DEBUG::LTC, "LTC reset()\n");
  96         last_timestamp = 0;
  97         current_delta = 0;
  98         transport_direction = 0;
  99         ltc_speed = 0;
 100         engine_dll_initstate = 0;
 101         fps_detected=false;
 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::detect_discontinuity(LTCFrameExt *frame, int fps, bool fuzzy) {
 126         bool discontinuity_detected = false;
 127
 128         if (fuzzy && (
 129                   (frame->reverse  && prev_frame.ltc.frame_units == 0)
 130                 ||(!frame->reverse && frame->ltc.frame_units == 0)
 131                 ))
 132         {
 133                 memcpy(&prev_frame, frame, sizeof(LTCFrameExt));
 134                 return false;
 135         }
 136
 137         if (frame->reverse) {
 138                 ltc_frame_decrement(&prev_frame.ltc, fps , 0);
 139         } else {
 140                 ltc_frame_increment(&prev_frame.ltc, fps , 0);
 141         }
 142
 143         LTCFrame *a = &prev_frame.ltc;
 144         LTCFrame *b = &frame->ltc;
 145         if (       a->frame_units != b->frame_units
 146                 || a->frame_tens  != b->frame_tens
 147                 || a->dfbit       != b->dfbit
 148                 || a->secs_units  != b->secs_units
 149                 || a->secs_tens   != b->secs_tens
 150                 || a->mins_units  != b->mins_units
 151                 || a->mins_tens   != b->mins_tens
 152                 || a->hours_units != b->hours_units
 153                 || a->hours_tens  != b->hours_tens
 154              )
 155         {
 156                 discontinuity_detected = true;
 157         }
 158
 159     memcpy(&prev_frame, frame, sizeof(LTCFrameExt));
 160     return discontinuity_detected;
 161 }
 162
 163 bool
 164 LTC_Slave::detect_ltc_fps(int frameno, bool df)
 165 {
 166         double detected_fps = 0;
 167         if (frameno > ltc_detect_fps_max)
 168         {
 169                 ltc_detect_fps_max = frameno;
 170         }
 171         ltc_detect_fps_cnt++;
 172
 173         if (ltc_detect_fps_cnt > 40)
 174         {
 175                 if (ltc_detect_fps_cnt > ltc_detect_fps_max
 176                     && (   ceil(timecode.rate) != (ltc_detect_fps_max + 1)
 177                         || timecode.drop != df
 178                         )
 179                     )
 180                 {
 181                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC detected FPS %1%2",
 182                                         ltc_detect_fps_max + 1, timecode.drop ? "df" : ""));
 183                         detected_fps = ltc_detect_fps_max + 1;
 184                         if (df) {
 185                                 /* LTC df -> indicates fractional framerate */
 186                                 detected_fps = detected_fps * 1000.0 / 1001.0;
 187                         }
 188                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC detected FPS: %1%2\n", detected_fps, df?"df":"ndf"));
 189                 }
 190                 ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
 191         }
 192
 193         /* when changed */
 194         if (detected_fps != 0 && (detected_fps != timecode.rate || df != timecode.drop)) {
 195                 timecode.rate = detected_fps;
 196                 timecode.drop = df;
 197                 frames_per_ltc_frame = double(session.frame_rate()) / timecode.rate;
 198                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC reset to FPS: %1%2 ; audio-frames per LTC: %3\n",
 199                                 detected_fps, df?"df":"ndf", frames_per_ltc_frame));
 200                 return true; // reset()
 201         }
 202
 203         /* poll and check session TC */
 204         if (1) {
 205                 TimecodeFormat tc_format = apparent_timecode_format();
 206                 TimecodeFormat cur_timecode = session.config.get_timecode_format();
 207                 if (Config->get_timecode_sync_frame_rate()) {
 208                         /* enforce time-code */
 209                         if (!did_reset_tc_format) {
 210                                 saved_tc_format = cur_timecode;
 211                                 did_reset_tc_format = true;
 212                         }
 213                         if (cur_timecode != tc_format) {
 214                                 warning << string_compose(_("Session framerate adjusted from %1 to LTC's %2."),
 215                                                 Timecode::timecode_format_name(cur_timecode),
 216                                                 Timecode::timecode_format_name(tc_format))
 217                                         << endmsg;
 218                                 session.config.set_timecode_format (tc_format);
 219                         }
 220                 } else {
 221                         /* only warn about TC mismatch */
 222                         if (ltc_timecode != tc_format) printed_timecode_warning = false;
 223                         if (a3e_timecode != cur_timecode) printed_timecode_warning = false;
 224
 225                         if (cur_timecode != tc_format && ! printed_timecode_warning) {
 226                                 warning << string_compose(_("Session and LTC framerate mismatch: LTC:%1 Session:%2."),
 227                                                 Timecode::timecode_format_name(tc_format),
 228                                                 Timecode::timecode_format_name(cur_timecode))
 229                                         << endmsg;
 230                                 printed_timecode_warning = true;
 231                         }
 232                 }
 233                 ltc_timecode = tc_format;
 234                 a3e_timecode = cur_timecode;
 235         }
 236         return false;
 237 }
 238
 239 void
 240 LTC_Slave::process_ltc(framepos_t const now)
 241 {
 242         LTCFrameExt frame;
 243         while (ltc_decoder_read(decoder, &frame)) {
 244                 SMPTETimecode stime;
 245
 246                 ltc_frame_to_time(&stime, &frame.ltc, 0);
 247                 timecode.negative  = false;
 248                 timecode.subframes  = 0;
 249
 250                 /* set timecode.rate and timecode.drop: */
 251
 252                 if (detect_discontinuity(&frame, ceil(timecode.rate), !fps_detected)) {
 253                         ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
 254                         fps_detected=false;
 255                 }
 256
 257                 if (detect_ltc_fps(stime.frame, (frame.ltc.dfbit)? true : false)) {
 258                         reset();
 259                         last_timestamp = 0;
 260                         fps_detected=true;
 261                 }
 262
 263 #if 0 // Devel/Debug
 264                 fprintf(stdout, "LTC %02d:%02d:%02d%c%02d | %8lld %8lld%s\n",
 265                         stime.hours,
 266                         stime.mins,
 267                         stime.secs,
 268                         (frame.ltc.dfbit) ? '.' : ':',
 269                         stime.frame,
 270                         frame.off_start,
 271                         frame.off_end,
 272                         frame.reverse ? " R" : "  "
 273                         );
 274 #endif
 275
 276                 /* when a full LTC frame is decoded, the timecode the LTC frame
 277                  * is referring has just passed.
 278                  * So we send the _next_ timecode which
 279                  * is expected to start at the end of the current frame
 280                  */
 281                 int fps_i = ceil(timecode.rate);
 282                 if (!frame.reverse) {
 283                         ltc_frame_increment(&frame.ltc, fps_i , 0);
 284                         ltc_frame_to_time(&stime, &frame.ltc, 0);
 285                         transport_direction = 1;
 286                 } else {
 287                         ltc_frame_decrement(&frame.ltc, fps_i , 0);
 288                         int off = frame.off_end - frame.off_start;
 289                         frame.off_start += off;
 290                         frame.off_end += off;
 291                         transport_direction = -1;
 292                 }
 293
 294                 timecode.hours   = stime.hours;
 295                 timecode.minutes = stime.mins;
 296                 timecode.seconds = stime.secs;
 297                 timecode.frames  = stime.frame;
 298
 299                 /* map LTC timecode to session TC setting */
 300                 framepos_t ltc_frame; ///< audio-frame corresponding to LTC frame
 301                 Timecode::timecode_to_sample (timecode, ltc_frame, true, false,
 302                         double(session.frame_rate()),
 303                         session.config.get_subframes_per_frame(),
 304                         session.config.get_timecode_offset_negative(), session.config.get_timecode_offset()
 305                         );
 306
 307                 framepos_t cur_timestamp = frame.off_end + 1;
 308                 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));
 309                 if (frame.off_end + 1 <= last_timestamp || last_timestamp == 0) {
 310                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC speed: UNCHANGED: %1\n", ltc_speed));
 311                 } else {
 312                         ltc_speed = double(ltc_frame - last_ltc_frame) / double(cur_timestamp - last_timestamp);
 313                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC speed: %1\n", ltc_speed));
 314                 }
 315
 316                 if (fabs(ltc_speed) > 10.0) {
 317                         ltc_speed = 0;
 318                 }
 319
 320                 last_timestamp = frame.off_end + 1;
 321                 last_ltc_frame = ltc_frame;
 322         } /* end foreach decoded LTC frame */
 323 }
 324
 325 void
 326 LTC_Slave::init_engine_dll (framepos_t pos, int32_t inc)
 327 {
 328         double omega = 2.0 * M_PI * double(inc) / double(session.frame_rate());
 329         b = 1.4142135623730950488 * omega;
 330         c = omega * omega;
 331
 332         e2 = double(ltc_speed * inc);
 333         t0 = double(pos);
 334         t1 = t0 + e2;
 335         DEBUG_TRACE (DEBUG::LTC, string_compose ("[re-]init Engine DLL %1 %2 %3\n", t0, t1, e2));
 336 }
 337
 338 /* main entry point from session_process.cc
 339  * called from jack_process callback context
 340  * so it is OK to use jack_port_get_buffer()
 341  */
 342 bool
 343 LTC_Slave::speed_and_position (double& speed, framepos_t& pos)
 344 {
 345         bool engine_init_called = false;
 346         framepos_t now = session.engine().frame_time_at_cycle_start();
 347         framepos_t sess_pos = session.transport_frame(); // corresponds to now
 348         framecnt_t nframes = session.engine().frames_per_cycle();
 349
 350         jack_default_audio_sample_t *in;
 351         jack_latency_range_t ltc_latency;
 352
 353         boost::shared_ptr<Port> ltcport = session.ltc_input_port();
 354         ltcport->get_connected_latency_range(ltc_latency, false);
 355         in = (jack_default_audio_sample_t*) jack_port_get_buffer (ltcport->jack_port(), nframes);
 356
 357         frameoffset_t skip = now - (monotonic_cnt + nframes);
 358         monotonic_cnt = now;
 359         DEBUG_TRACE (DEBUG::LTC, string_compose ("speed_and_position - TID:%1 | latency: %2 | skip %3\n", ::pthread_self(), ltc_latency.max, skip));
 360
 361         if (last_timestamp == 0) {
 362                 engine_dll_initstate = 0;
 363                 delayedlocked++;
 364         }
 365         else if (engine_dll_initstate != transport_direction && ltc_speed != 0) {
 366                 engine_dll_initstate = transport_direction;
 367                 init_engine_dll(last_ltc_frame + rint(ltc_speed * double(2 * nframes + now - last_timestamp)),
 368                                 session.engine().frames_per_cycle());
 369                 engine_init_called = true;
 370         }
 371
 372         if (in) {
 373                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC Process eng-tme: %1 eng-pos: %2\n", now, sess_pos));
 374                 /* when the jack-graph changes and if ardour performs
 375                  * locates, the audioengine is stopped (skipping frames) while
 376                  * jack [time] moves along.
 377                  */
 378                 if (skip > 0) {
 379                         DEBUG_TRACE (DEBUG::LTC, string_compose("engine skipped %1 frames. Feeding silence to LTC parser.\n", skip));
 380                         if (skip >= 8192) skip = 8192;
 381                         unsigned char sound[8192];
 382                         memset(sound, 0, sizeof(char) * skip);
 383                         ltc_decoder_write(decoder, sound, nframes, now);
 384                 } else if (skip != 0) {
 385                         /* this should never happen. it may if monotonic_cnt, now overflow on 64bit */
 386                         DEBUG_TRACE (DEBUG::LTC, string_compose("engine skipped %1 frames\n", skip));
 387                         reset();
 388                 }
 389
 390                 parse_ltc(nframes, in, now + ltc_latency.max );
 391                 process_ltc(now);
 392         }
 393
 394         if (last_timestamp == 0) {
 395                 DEBUG_TRACE (DEBUG::LTC, "last timestamp == 0\n");
 396                 speed = 0;
 397                 pos = session.transport_frame();
 398                 return true;
 399         } else if (ltc_speed != 0) {
 400                 delayedlocked = 0;
 401         }
 402
 403         if (abs(now - last_timestamp) > FLYWHEEL_TIMEOUT) {
 404                 DEBUG_TRACE (DEBUG::LTC, "flywheel timeout\n");
 405                 reset();
 406                 speed = 0;
 407                 pos = session.transport_frame();
 408                 return true;
 409         }
 410
 411         /* it take 2 cycles from naught to rolling.
 412          * during these to initial cycles the speed == 0
 413          *
 414          * the first cycle:
 415          * DEBUG::Slave: slave stopped, move to NNN
 416          * DEBUG::Transport: Request forced locate to NNN
 417          * DEBUG::Slave: slave state 0 @ NNN speed 0 cur delta VERY-LARGE-DELTA avg delta 1800
 418          * DEBUG::Slave: silent motion
 419          * DEBUG::Transport: realtime stop @ NNN
 420          * DEBUG::Transport: Butler transport work, todo = PostTransportStop,PostTransportLocate,PostTransportClearSubstate
 421          *
 422          * [engine skips frames to locate, jack time keeps rolling on]
 423          *
 424          * the second cycle:
 425          *
 426          * DEBUG::LTC: [re-]init Engine DLL
 427          * DEBUG::Slave: slave stopped, move to NNN+
 428          * ...
 429          *
 430          * we need to seek two cycles ahead: 2 * nframes
 431          */
 432         if (engine_dll_initstate == 0) {
 433                 DEBUG_TRACE (DEBUG::LTC, "engine DLL not initialized. ltc_speed\n");
 434                 speed = 0;
 435                 pos = last_ltc_frame + rint(ltc_speed * double(2 * nframes + now - last_timestamp));
 436                 return true;
 437         }
 438
 439         /* interpolate position according to speed and time since last LTC-frame*/
 440         double speed_flt = ltc_speed;
 441         double elapsed = (now - last_timestamp) * speed_flt;
 442
 443         if (!engine_init_called) {
 444                 const double e = elapsed + double (last_ltc_frame - sess_pos);
 445                 t0 = t1;
 446                 t1 += b * e + e2;
 447                 e2 += c * e;
 448                 speed_flt = (t1 - t0) / double(session.engine().frames_per_cycle());
 449                 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() ));
 450         } else {
 451                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC adjusting elapsed (no DLL) from %1 by %2\n", elapsed, (2 * nframes * ltc_speed)));
 452                 speed_flt = 0;
 453                 elapsed += 2.0 * nframes * ltc_speed; /* see note above */
 454         }
 455
 456         pos = last_ltc_frame + rint(elapsed);
 457         speed = speed_flt;
 458         current_delta = (pos - sess_pos);
 459
 460         if (((pos < 0) || (labs(current_delta) > 2 * session.frame_rate()))) {
 461                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC large drift: %1\n", current_delta));
 462                 reset();
 463                 speed = 0;
 464                 pos = session.transport_frame();
 465                 return true;
 466         }
 467
 468         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTCsync spd: %1 pos: %2 | last-pos: %3 elapsed: %4 delta: %5\n",
 469                                                  speed, pos, last_ltc_frame, elapsed, current_delta));
 470
 471 #if 1 /* provide a .1% deadzone to lock the speed */
 472         if (fabs(speed - 1.0) <= 0.001)
 473                 speed = 1.0;
 474 #endif
 475
 476         return true;
 477 }
 478
 479 Timecode::TimecodeFormat
 480 LTC_Slave::apparent_timecode_format () const
 481 {
 482         if      (timecode.rate == 24 && !timecode.drop)
 483                 return timecode_24;
 484         else if (timecode.rate == 25 && !timecode.drop)
 485                 return timecode_25;
 486         else if (rint(timecode.rate * 100) == 2997 && !timecode.drop)
 487                 return timecode_2997;
 488         else if (rint(timecode.rate * 100) == 2997 &&  timecode.drop)
 489                 return timecode_2997drop;
 490         else if (timecode.rate == 30 &&  timecode.drop)
 491                 return timecode_2997drop; // timecode_30drop; // LTC counting to 30 frames w/DF *means* 29.97 df
 492         else if (timecode.rate == 30 && !timecode.drop)
 493                 return timecode_30;
 494
 495         /* XXX - unknown timecode format */
 496         return session.config.get_timecode_format();
 497 }
 498
 499 std::string
 500 LTC_Slave::approximate_current_position() const
 501 {
 502         if (last_timestamp == 0) {
 503                 return " --:--:--:--";
 504         }
 505         return Timecode::timecode_format_time(timecode);
 506 }
 507
 508 std::string
 509 LTC_Slave::approximate_current_delta() const
 510 {
 511         char delta[24];
 512         if (last_timestamp == 0 || engine_dll_initstate == 0) {
 513                 snprintf(delta, sizeof(delta), "\u2012\u2012\u2012\u2012");
 514         } else if ((monotonic_cnt - last_timestamp) > 2 * frames_per_ltc_frame) {
 515                 snprintf(delta, sizeof(delta), "flywheel");
 516         } else {
 517                 snprintf(delta, sizeof(delta), "%s%4" PRIi64 " sm",
 518                                 PLUSMINUS(-current_delta), abs(current_delta));
 519         }
 520         return std::string(delta);
 521 }