libs/midi++2/mtc.cc

   1 /*
   2     Copyright (C) 2004 Paul Barton-Davis
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18     $Id$
  19 */
  20
  21 #include <cstdlib>
  22 #include <unistd.h>
  23 #include <cstring>
  24 #include <iostream>
  25
  26 #include "midi++/types.h"
  27 #include "midi++/parser.h"
  28 #include "midi++/port.h"
  29 #include "midi++/mmc.h"
  30 #include "pbd/transmitter.h"
  31
  32 using namespace std;
  33 using namespace sigc;
  34 using namespace MIDI;
  35
  36 #undef DEBUG_MTC
  37
  38 bool
  39 Parser::possible_mtc (byte *sysex_buf, size_t msglen)
  40 {
  41         byte fake_mtc_time[5];
  42
  43         if (msglen != 10 || sysex_buf[0] != 0xf0 || sysex_buf[1] != 0x7f || sysex_buf[3] != 0x01 || sysex_buf[4] != 0x01) {
  44                 return false;
  45         }
  46
  47         /* full MTC */
  48
  49         fake_mtc_time[0] = sysex_buf[8]; // frames
  50         fake_mtc_time[1] = sysex_buf[7]; // minutes
  51         fake_mtc_time[2] = sysex_buf[6]; // seconds
  52         fake_mtc_time[3] = (sysex_buf[5] & 0x1f); // hours
  53
  54         _mtc_fps = MTC_FPS ((sysex_buf[5] & 0x60) >> 5); // fps
  55         fake_mtc_time[4] = (byte) _mtc_fps;
  56
  57         /* wait for first quarter frame, which could indicate forwards
  58            or backwards ...
  59         */
  60
  61         reset_mtc_state ();
  62
  63         /* emit signals */
  64
  65         mtc (*this, &sysex_buf[1], msglen - 1);
  66         mtc_time (fake_mtc_time, true, _timestamp);
  67 #ifdef DEBUG_MTC
  68         cerr << "New full-MTC message marks state stopped" << endl;
  69 #endif
  70         mtc_status (MTC_Stopped);
  71
  72         return true;
  73 }
  74
  75 void
  76 Parser::reset_mtc_state ()
  77 {
  78 #ifdef DEBUG_MTC
  79         cerr << "MTC state reset" << endl;
  80 #endif
  81         /* MUST REMAIN RT-SAFE */
  82
  83         _mtc_forward = false;
  84         _mtc_running = MTC_Stopped;
  85         _mtc_locked = false;
  86         expected_mtc_quarter_frame_code = 0;
  87         memset (_mtc_time, 0, sizeof (_mtc_time));
  88         memset (_qtr_mtc_time, 0, sizeof (_mtc_time));
  89         consecutive_qtr_frame_cnt = 0;
  90         last_qtr_frame = 0;
  91 }
  92
  93 void
  94 Parser::process_mtc_quarter_frame (byte *msg)
  95 {
  96         int which_quarter_frame = (msg[1] & 0xf0) >> 4;
  97
  98         /* Is it an expected frame?
  99            Remember, the first can be frame 7 or frame 0,
 100            depending on the direction of the MTC generator ...
 101         */
 102
 103 #ifdef DEBUG_MTC
 104          cerr << "MTC: (state = " << _mtc_running << ") "
 105               << which_quarter_frame << " vs. " << expected_mtc_quarter_frame_code
 106               << " consecutive ? " << consecutive_qtr_frame_cnt
 107               << endl;
 108 #endif
 109
 110         if (_mtc_running == MTC_Stopped) {
 111
 112                 /* we are stopped but are seeing qtr frame messages */
 113
 114                 if (consecutive_qtr_frame_cnt == 0) {
 115
 116                         /* first quarter frame */
 117
 118                         if (which_quarter_frame != 0 && which_quarter_frame != 7) {
 119
 120                                 last_qtr_frame = which_quarter_frame;
 121                                 consecutive_qtr_frame_cnt++;
 122                         }
 123
 124                         // cerr << "first seen qframe = " << (int) last_qtr_frame << endl;
 125
 126                         return;
 127
 128                 } else if (consecutive_qtr_frame_cnt == 1) {
 129
 130                         /* third quarter frame */
 131
 132 #ifdef DEBUG_MTC
 133                         cerr << "second seen qframe = " << (int) which_quarter_frame << endl;
 134 #endif
 135                         if (last_qtr_frame < which_quarter_frame) {
 136                                 _mtc_running = MTC_Forward;
 137                         } else if (last_qtr_frame > which_quarter_frame) {
 138                                 _mtc_running = MTC_Backward;
 139                         }
 140 #ifdef DEBUG_MTC
 141                         cerr << "Send MTC status as " << _mtc_running << endl;
 142 #endif
 143                         mtc_status (_mtc_running);
 144                 }
 145
 146                 switch (_mtc_running) {
 147                 case MTC_Forward:
 148                         if (which_quarter_frame == 7) {
 149                                 expected_mtc_quarter_frame_code = 0;
 150                         } else {
 151                                 expected_mtc_quarter_frame_code = which_quarter_frame + 1;
 152                         }
 153                         break;
 154
 155                 case MTC_Backward:
 156                         if (which_quarter_frame == 0) {
 157                                 expected_mtc_quarter_frame_code = 7;
 158
 159                         } else {
 160                                 expected_mtc_quarter_frame_code = which_quarter_frame - 1;
 161                         }
 162                         break;
 163
 164                 case MTC_Stopped:
 165                         break;
 166                 }
 167
 168         } else {
 169
 170                 /* already running */
 171
 172 // for testing bad MIDI connections etc.
 173 //              if ((random() % 500) < 10) {
 174
 175                 if (which_quarter_frame != expected_mtc_quarter_frame_code) {
 176
 177                         consecutive_qtr_frame_cnt = 0;
 178
 179 #ifdef DEBUG_MTC
 180                         cerr << "MTC: (state = " << _mtc_running << ") "
 181                              << which_quarter_frame << " vs. " << expected_mtc_quarter_frame_code << endl;
 182 #endif
 183
 184                         /* tell listener(s) that we skipped. if they return
 185                            true, just ignore this in terms of it being an error.
 186                         */
 187
 188                         boost::optional<bool> res = mtc_skipped ();
 189
 190                         if (res.get_value_or (false)) {
 191
 192                                 /* no error, reset next expected frame */
 193
 194                                 switch (_mtc_running) {
 195                                 case MTC_Forward:
 196                                         if (which_quarter_frame == 7) {
 197                                                 expected_mtc_quarter_frame_code = 0;
 198                                         } else {
 199                                                 expected_mtc_quarter_frame_code = which_quarter_frame + 1;
 200                                         }
 201                                         break;
 202
 203                                 case MTC_Backward:
 204                                         if (which_quarter_frame == 0) {
 205                                                 expected_mtc_quarter_frame_code = 7;
 206
 207                                         } else {
 208                                                 expected_mtc_quarter_frame_code = which_quarter_frame - 1;
 209                                         }
 210                                         break;
 211
 212                                 case MTC_Stopped:
 213                                         break;
 214                                 }
 215
 216 #ifdef DEBUG_MTC
 217                                 cerr << "SKIPPED, next expected = " << expected_mtc_quarter_frame_code << endl;
 218 #endif
 219                                 return;
 220                         }
 221
 222                         /* skip counts as an error ... go back to waiting for the first frame */
 223
 224 #ifdef DEBUG_MTC
 225                         cerr << "Skipped MTC qtr frame, return to stopped state" << endl;
 226 #endif
 227                         reset_mtc_state ();
 228                         mtc_status (MTC_Stopped);
 229
 230                         return;
 231
 232                 } else {
 233
 234                         /* received qtr frame matched expected */
 235                         consecutive_qtr_frame_cnt++;
 236
 237                 }
 238         }
 239
 240         /* time code is looking good */
 241
 242 #ifdef DEBUG_MTC
 243         // cerr << "for quarter frame " << which_quarter_frame << " byte = " << hex << (int) msg[1] << dec << endl;
 244 #endif
 245
 246         switch (which_quarter_frame) {
 247         case 0: // frames LS nibble
 248                 _qtr_mtc_time[0] |= msg[1] & 0xf;
 249                 break;
 250
 251         case 1:  // frames MS nibble
 252                 _qtr_mtc_time[0] |= (msg[1] & 0xf)<<4;
 253                 break;
 254
 255         case 2: // seconds LS nibble
 256                 _qtr_mtc_time[1] |= msg[1] & 0xf;
 257                 break;
 258
 259         case 3: // seconds MS nibble
 260                 _qtr_mtc_time[1] |= (msg[1] & 0xf)<<4;
 261                 break;
 262
 263         case 4: // minutes LS nibble
 264                 _qtr_mtc_time[2] |= msg[1] & 0xf;
 265                 break;
 266
 267         case 5: // minutes MS nibble
 268                 _qtr_mtc_time[2] |= (msg[1] & 0xf)<<4;
 269                 break;
 270
 271         case 6: // hours LS nibble
 272                 _qtr_mtc_time[3] |= msg[1] & 0xf;
 273                 break;
 274
 275         case 7:
 276
 277                 /* last quarter frame msg has the MS bit of
 278                    the hour in bit 0, and the SMPTE FPS type
 279                    in bits 5 and 6
 280                 */
 281
 282                 _qtr_mtc_time[3] |= ((msg[1] & 0x1) << 4);
 283                 _mtc_fps = MTC_FPS ((msg[1] & 0x6) >> 1);
 284                 _qtr_mtc_time[4] = _mtc_fps;
 285                 break;
 286
 287         default:
 288                 /*NOTREACHED*/
 289                 break;
 290
 291         }
 292
 293 #ifdef DEBUG_MTC
 294         cerr << "Emit MTC Qtr\n";
 295 #endif
 296
 297         mtc_qtr (*this, which_quarter_frame, _timestamp); /* EMIT_SIGNAL */
 298
 299         // mtc (*this, &msg[1], msglen - 1);
 300
 301         switch (_mtc_running) {
 302         case MTC_Forward:
 303                 if ((which_quarter_frame == 7)) {
 304
 305                         /* we've reached the final of 8 quarter frame messages.
 306                            store the time, reset the pending time holder,
 307                            and signal anyone who wants to know the time.
 308                         */
 309
 310                         if (consecutive_qtr_frame_cnt >= 8) {
 311                                 memcpy (_mtc_time, _qtr_mtc_time, sizeof (_mtc_time));
 312                                 memset (_qtr_mtc_time, 0, sizeof (_qtr_mtc_time));
 313                                 if (!_mtc_locked) {
 314                                         _mtc_locked = true;
 315                                 }
 316
 317                                 mtc_time (_mtc_time, false, _timestamp);
 318                         }
 319                         expected_mtc_quarter_frame_code = 0;
 320
 321                 } else {
 322                         expected_mtc_quarter_frame_code = which_quarter_frame + 1;
 323                 }
 324                 break;
 325
 326         case MTC_Backward:
 327                 if (which_quarter_frame == 0) {
 328
 329                         /* we've reached the final of 8 quarter frame messages.
 330                            store the time, reset the pending time holder,
 331                            and signal anyone who wants to know the time.
 332                         */
 333
 334                         if (consecutive_qtr_frame_cnt >= 8) {
 335                                 memcpy (_mtc_time, _qtr_mtc_time, sizeof (_mtc_time));
 336                                 memset (_qtr_mtc_time, 0, sizeof (_qtr_mtc_time));
 337                                 if (!_mtc_locked) {
 338                                         _mtc_locked = true;
 339                                 }
 340                                 mtc_time (_mtc_time, false, _timestamp);
 341                         }
 342
 343                         expected_mtc_quarter_frame_code = 7;
 344
 345                 } else {
 346                         expected_mtc_quarter_frame_code = which_quarter_frame - 1;
 347                 }
 348                 break;
 349
 350         default:
 351                 break;
 352         }
 353
 354 }