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 LTC_Slave::LTC_Slave (Session& s)
  43         : session (s)
  44 {
  45         frames_per_ltc_frame = session.frames_per_timecode_frame();
  46         timecode.rate = session.timecode_frames_per_second();
  47         timecode.drop  = session.timecode_drop_frames();
  48
  49         printf("LTC initial rate: %f %f\n", timecode.rate, frames_per_ltc_frame);
  50
  51         ltc_transport_pos = 0;
  52         ltc_speed = 1.0;
  53         last_timestamp = 0;
  54         ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
  55
  56         ltc_timecode = timecode_60; // track changes of LTC timecode
  57         a3e_timecode = timecode_60; // track canges of Ardour's timecode
  58         printed_timecode_warning = false;
  59
  60         decoder = ltc_decoder_create((int) frames_per_ltc_frame, 128 /*queue size*/);
  61 }
  62
  63 LTC_Slave::~LTC_Slave()
  64 {
  65         if (did_reset_tc_format) {
  66                 session.config.set_timecode_format (saved_tc_format);
  67         }
  68
  69         ltc_decoder_free(decoder);
  70 }
  71
  72 bool
  73 LTC_Slave::give_slave_full_control_over_transport_speed() const
  74 {
  75         return true; // DLL align to engine transport
  76         // return false; // for Session-level computed varispeed
  77 }
  78
  79 ARDOUR::framecnt_t
  80 LTC_Slave::resolution () const
  81 {
  82         return (framecnt_t) (frames_per_ltc_frame);
  83 }
  84
  85 ARDOUR::framecnt_t
  86 LTC_Slave::seekahead_distance () const
  87 {
  88         return (framecnt_t) (frames_per_ltc_frame * 2);
  89 }
  90
  91 bool
  92 LTC_Slave::locked () const
  93 {
  94         return true; // TODO check if >2 sequential LTC frames have been received
  95 }
  96
  97 bool
  98 LTC_Slave::ok() const
  99 {
 100         return true;
 101 }
 102
 103 int
 104 LTC_Slave::parse_ltc(const jack_nframes_t nframes, const jack_default_audio_sample_t * const in, const framecnt_t posinfo)
 105 {
 106         jack_nframes_t i;
 107         unsigned char sound[8192];
 108         if (nframes > 8192) return 1;
 109
 110         for (i = 0; i < nframes; i++) {
 111                 const int snd=(int)rint((127.0*in[i])+128.0);
 112                 sound[i] = (unsigned char) (snd&0xff);
 113         }
 114         ltc_decoder_write(decoder, sound, nframes, posinfo);
 115         return 0;
 116 }
 117
 118 void
 119 LTC_Slave::detect_ltc_fps(int frameno, bool df)
 120 {
 121         double detected_fps = 0;
 122         if (frameno > ltc_detect_fps_max)
 123         {
 124                 ltc_detect_fps_max = frameno;
 125         }
 126         ltc_detect_fps_cnt++;
 127         if (ltc_detect_fps_cnt > 60)
 128         {
 129                 if (ltc_detect_fps_cnt > ltc_detect_fps_max
 130                     && (   ceil(timecode.rate) != (ltc_detect_fps_max + 1)
 131                         || timecode.drop != df
 132                         )
 133                     )
 134                 {
 135                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC detected FPS %1%2",
 136                                         ltc_detect_fps_max + 1, timecode.drop ? "df" : ""));
 137                         detected_fps = ltc_detect_fps_max + 1;
 138                         if (df) {
 139                                 /* LTC df -> indicates fractional framerate */
 140                                 detected_fps = detected_fps * 1000.0 / 1001.0;
 141                         }
 142                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC detected FPS: %1%2\n", detected_fps, df?"df":"ndf"));
 143                 }
 144                 ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
 145         }
 146
 147         /* when changed */
 148         if (detected_fps != 0 && (detected_fps != timecode.rate || df != timecode.drop)) {
 149                 timecode.rate = detected_fps;
 150                 timecode.drop = df;
 151                 frames_per_ltc_frame = double(session.frame_rate()) / timecode.rate;
 152                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC reset to FPS: %1%2 ; audio-frames per LTC: %3\n",
 153                                 detected_fps, df?"df":"ndf", frames_per_ltc_frame));
 154                 last_timestamp = 0; // re-init
 155         }
 156
 157         /* poll and check session TC */
 158         if (1) {
 159                 TimecodeFormat tc_format = apparent_timecode_format();
 160                 TimecodeFormat cur_timecode = session.config.get_timecode_format();
 161                 if (Config->get_timecode_sync_frame_rate()) {
 162                         /* enforce time-code */
 163                         if (!did_reset_tc_format) {
 164                                 saved_tc_format = cur_timecode;
 165                                 did_reset_tc_format = true;
 166                         }
 167                         if (cur_timecode != tc_format) {
 168                                 warning << string_compose(_("Session framerate adjusted from %1 TO: LTC's %2."),
 169                                                 Timecode::timecode_format_name(cur_timecode),
 170                                                 Timecode::timecode_format_name(tc_format))
 171                                         << endmsg;
 172                         }
 173                         session.config.set_timecode_format (tc_format);
 174                 } else {
 175                         /* only warn about TC mismatch */
 176                         if (ltc_timecode != tc_format) printed_timecode_warning = false;
 177                         if (a3e_timecode != cur_timecode) printed_timecode_warning = false;
 178
 179                         if (cur_timecode != tc_format && ! printed_timecode_warning) {
 180                                 warning << string_compose(_("Session and LTC framerate mismatch: LTC:%1 Session:%2."),
 181                                                 Timecode::timecode_format_name(tc_format),
 182                                                 Timecode::timecode_format_name(cur_timecode))
 183                                         << endmsg;
 184                                 printed_timecode_warning = true;
 185                         }
 186                 }
 187                 ltc_timecode = tc_format;
 188                 a3e_timecode = cur_timecode;
 189         }
 190
 191 }
 192
 193 bool
 194 LTC_Slave::process_ltc(framepos_t now, framecnt_t nframes)
 195 {
 196         bool have_frame = false;
 197
 198         framepos_t sess_pos = session.transport_frame(); // corresponds to now
 199         //sess_pos -= session.engine().frames_since_cycle_start();
 200
 201         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC Process eng-tme: %1 eng-pos: %2\n", now, sess_pos));
 202
 203         LTCFrameExt frame;
 204         while (ltc_decoder_read(decoder,&frame)) {
 205                 SMPTETimecode stime;
 206                 ltc_frame_to_time(&stime, &frame.ltc, 0);
 207
 208 #if 0 // Devel/Debug
 209                 fprintf(stdout, "LTC %02d:%02d:%02d%c%02d | %8lld %8lld%s\n",
 210                         stime.hours,
 211                         stime.mins,
 212                         stime.secs,
 213                         (frame.ltc.dfbit) ? '.' : ':',
 214                         stime.frame,
 215                         frame.off_start,
 216                         frame.off_end,
 217                         frame.reverse ? " R" : "  "
 218                         );
 219 #endif
 220
 221                 timecode.negative  = false;
 222                 timecode.subframes  = 0;
 223                 /* set timecode.rate and timecode.drop: */
 224                 detect_ltc_fps(stime.frame, (frame.ltc.dfbit)? true : false);
 225
 226                 /* when a full LTC frame is decoded, the timecode the LTC frame
 227                  * is referring has just passed.
 228                  * So we send the _next_ timecode which
 229                  * is expected to start at the end of the current frame
 230                  */
 231                 int fps_i = ceil(timecode.rate);
 232                 if (!frame.reverse) {
 233                         ltc_frame_increment(&frame.ltc, fps_i , 0);
 234                         ltc_frame_to_time(&stime, &frame.ltc, 0);
 235                 } else {
 236                         ltc_frame_decrement(&frame.ltc, fps_i , 0);
 237                         int off = frame.off_end - frame.off_start;
 238                         frame.off_start += off;
 239                         frame.off_end += off;
 240                 }
 241
 242                 timecode.hours   = stime.hours;
 243                 timecode.minutes = stime.mins;
 244                 timecode.seconds = stime.secs;
 245                 timecode.frames  = stime.frame;
 246
 247                 framepos_t ltc_frame;
 248                 Timecode::timecode_to_sample (timecode, ltc_frame, true, false,
 249                         double(session.frame_rate()),
 250                         session.config.get_subframes_per_frame(),
 251                         session.config.get_timecode_offset_negative(), session.config.get_timecode_offset()
 252                         );
 253
 254                 double poff = (frame.off_end - now);
 255
 256                 ltc_transport_pos = ltc_frame - poff;
 257                 frames_per_ltc_frame = (double(session.frame_rate()) / timecode.rate);
 258                 //frames_per_ltc_frame = frame.off_end - frame.off_start; // the first one is off.
 259
 260                 DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC frame: %1 poff: %2 pos :%3\n", ltc_frame, poff, ltc_transport_pos));
 261
 262                 if (last_timestamp == 0 || ((now - last_timestamp) > 4 * frames_per_ltc_frame) ) {
 263                         init_ltc_dll(ltc_frame, frames_per_ltc_frame);
 264                         ltc_speed = 1.0; // XXX
 265                 } else {
 266
 267                         double e = (double(ltc_frame) - poff - double(sess_pos));
 268                         // update DLL
 269                         t0 = t1;
 270                         t1 += b * e + e2;
 271                         e2 += c * e;
 272
 273                         ltc_speed = (t1 - t0) / frames_per_ltc_frame;
 274                         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));
 275
 276                 }
 277                 last_timestamp = now;
 278                 last_ltc_frame = ltc_frame;
 279                 have_frame = true;
 280         }
 281         return have_frame;
 282 }
 283
 284 void
 285 LTC_Slave::init_ltc_dll(framepos_t tme, double dt)
 286 {
 287         omega = 2.0 * M_PI * dt / double(session.frame_rate());
 288         b = 1.4142135623730950488 * omega;
 289         c = omega * omega;
 290
 291         e2 = dt;
 292         t0 = double(tme);
 293         t1 = t0 + e2;
 294         DEBUG_TRACE (DEBUG::LTC, string_compose ("[re-]init LTC DLL %1 %2 %3\n", t0, t1, e2));
 295 }
 296
 297 /* main entry point from session_process.cc
 298  * called from jack_process callback context
 299  * so it is OK to use jack_port_get_buffer() etc
 300  */
 301 bool
 302 LTC_Slave::speed_and_position (double& speed, framepos_t& pos)
 303 {
 304
 305         framepos_t now = session.engine().frame_time_at_cycle_start();
 306         framecnt_t nframes = session.engine().frames_per_cycle();
 307         jack_default_audio_sample_t *in;
 308         jack_latency_range_t ltc_latency;
 309
 310         boost::shared_ptr<Port> ltcport = session.engine().ltc_input_port();
 311         ltcport->get_connected_latency_range(ltc_latency, false);
 312         in = (jack_default_audio_sample_t*) jack_port_get_buffer (ltcport->jack_port(), nframes);
 313
 314         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC_Slave::speed_and_position - TID:%1 | latency: %2\n", ::pthread_self(), ltc_latency.max));
 315
 316         if (in) {
 317                 parse_ltc(nframes, in, now  + ltc_latency.max );
 318                 if (!process_ltc(now, nframes)) {
 319                         /* fly wheel */
 320                         double elapsed = (now - last_timestamp) * ltc_speed;
 321                         ltc_transport_pos = last_ltc_frame + elapsed;
 322                         DEBUG_TRACE (DEBUG::LTC, string_compose ("LTC fly wheel elapsed: %1 @speed %2\n", elapsed, ltc_speed));
 323                 }
 324         }
 325
 326         if (((now - last_timestamp) > 4 * frames_per_ltc_frame) ) {
 327                 DEBUG_TRACE (DEBUG::LTC, "LTC no-signal - reset\n");
 328                 speed = ltc_speed = 0;
 329                 pos = session.transport_frame();
 330                 last_timestamp = 0;
 331                 ltc_detect_fps_cnt = ltc_detect_fps_max = 0;
 332                 return true;
 333         }
 334
 335         pos = ltc_transport_pos;
 336         speed = ltc_speed;
 337
 338         return true;
 339 }
 340
 341 Timecode::TimecodeFormat
 342 LTC_Slave::apparent_timecode_format () const
 343 {
 344         if      (timecode.rate == 24 && !timecode.drop)
 345                 return timecode_24;
 346         else if (timecode.rate == 25 && !timecode.drop)
 347                 return timecode_25;
 348         else if (rint(timecode.rate * 100) == 2997 && !timecode.drop)
 349                 return timecode_2997;
 350         else if (rint(timecode.rate * 100) == 2997 &&  timecode.drop)
 351                 return timecode_2997drop;
 352         else if (timecode.rate == 30 &&  timecode.drop)
 353                 return timecode_2997drop; // timecode_30drop; // LTC counting to 30 frames w/DF *means* 29.97 df
 354         else if (timecode.rate == 30 && !timecode.drop)
 355                 return timecode_30;
 356
 357         /* XXX - unknown timecode format */
 358         return session.config.get_timecode_format();
 359 }
 360
 361 std::string
 362 LTC_Slave::approximate_current_position() const
 363 {
 364         if (last_timestamp == 0) {
 365                 return "--:--:--:--";
 366         }
 367         return Timecode::timecode_format_time(timecode);
 368 }