lib/dvb/tstools.cpp

   1 #define _ISOC99_SOURCE /* for llabs */
   2 #include <lib/dvb/tstools.h>
   3 #include <lib/base/eerror.h>
   4 #include <unistd.h>
   5 #include <fcntl.h>
   6
   7 #include <stdio.h>
   8
   9 eDVBTSTools::eDVBTSTools()
  10 {
  11         m_pid = -1;
  12         m_maxrange = 256*1024;
  13
  14         m_begin_valid = 0;
  15         m_end_valid = 0;
  16
  17         m_use_streaminfo = 0;
  18         m_samples_taken = 0;
  19
  20         m_last_filelength = 0;
  21
  22         m_futile = 0;
  23 }
  24
  25 eDVBTSTools::~eDVBTSTools()
  26 {
  27         closeFile();
  28 }
  29
  30 int eDVBTSTools::openFile(const char *filename, int nostreaminfo)
  31 {
  32         closeFile();
  33
  34         if (!nostreaminfo)
  35         {
  36                 eDebug("loading streaminfo for %s", filename);
  37                 m_streaminfo.load(filename);
  38         }
  39
  40         if (!m_streaminfo.empty())
  41                 m_use_streaminfo = 1;
  42         else
  43         {
  44 //              eDebug("no recorded stream information available");
  45                 m_use_streaminfo = 0;
  46         }
  47
  48         m_samples_taken = 0;
  49
  50         if (m_file.open(filename, 1) < 0)
  51                 return -1;
  52         return 0;
  53 }
  54
  55 void eDVBTSTools::closeFile()
  56 {
  57         m_file.close();
  58 }
  59
  60 void eDVBTSTools::setSyncPID(int pid)
  61 {
  62         m_pid = pid;
  63 }
  64
  65 void eDVBTSTools::setSearchRange(int maxrange)
  66 {
  67         m_maxrange = maxrange;
  68 }
  69
  70         /* getPTS extracts a pts value from any PID at a given offset. */
  71 int eDVBTSTools::getPTS(off_t &offset, pts_t &pts, int fixed)
  72 {
  73         if (m_use_streaminfo)
  74                 if (!m_streaminfo.getPTS(offset, pts))
  75                         return 0;
  76
  77         if (!m_file.valid())
  78                 return -1;
  79
  80         offset -= offset % 188;
  81
  82         if (m_file.lseek(offset, SEEK_SET) < 0)
  83         {
  84                 eDebug("lseek failed");
  85                 return -1;
  86         }
  87
  88         int left = m_maxrange;
  89
  90         while (left >= 188)
  91         {
  92                 unsigned char packet[188];
  93                 if (m_file.read(packet, 188) != 188)
  94                 {
  95                         eDebug("read error");
  96                         break;
  97                 }
  98                 left -= 188;
  99                 offset += 188;
 100
 101                 if (packet[0] != 0x47)
 102                 {
 103                         eDebug("resync");
 104                         int i = 0;
 105                         while (i < 188)
 106                         {
 107                                 if (packet[i] == 0x47)
 108                                         break;
 109                                 ++i;
 110                         }
 111                         offset = m_file.lseek(i - 188, SEEK_CUR);
 112                         continue;
 113                 }
 114
 115                 int pid = ((packet[1] << 8) | packet[2]) & 0x1FFF;
 116                 int pusi = !!(packet[1] & 0x40);
 117
 118 //              printf("PID %04x, PUSI %d\n", pid, pusi);
 119
 120                 unsigned char *payload;
 121
 122                         /* check for adaption field */
 123                 if (packet[3] & 0x20)
 124                 {
 125                         if (packet[4] >= 183)
 126                                 continue;
 127                         if (packet[4])
 128                         {
 129                                 if (packet[5] & 0x10) /* PCR present */
 130                                 {
 131                                         pts  = ((unsigned long long)(packet[ 6]&0xFF)) << 25;
 132                                         pts |= ((unsigned long long)(packet[ 7]&0xFF)) << 17;
 133                                         pts |= ((unsigned long long)(packet[ 8]&0xFE)) << 9;
 134                                         pts |= ((unsigned long long)(packet[ 9]&0xFF)) << 1;
 135                                         pts |= ((unsigned long long)(packet[10]&0x80)) >> 7;
 136                                         offset -= 188;
 137                                         eDebug("PCR  found at %llx: %16llx", offset, pts);
 138                                         if (fixed && fixupPTS(offset, pts))
 139                                                 return -1;
 140                                         return 0;
 141                                 }
 142                         }
 143                         payload = packet + packet[4] + 4 + 1;
 144                 } else
 145                         payload = packet + 4;
 146
 147
 148 /*              if (m_pid >= 0)
 149                         if (pid != m_pid)
 150                                 continue; */
 151                 if (!pusi)
 152                         continue;
 153
 154
 155                         /* somehow not a startcode. (this is invalid, since pusi was set.) ignore it. */
 156                 if (payload[0] || payload[1] || (payload[2] != 1))
 157                         continue;
 158
 159                         /* drop non-audio, non-video packets because other streams
 160                            can be non-compliant.*/
 161                 if (((payload[3] & 0xE0) != 0xC0) &&  // audio
 162                     ((payload[3] & 0xF0) != 0xE0))    // video
 163                         continue;
 164
 165                 if (payload[7] & 0x80) /* PTS */
 166                 {
 167                         pts  = ((unsigned long long)(payload[ 9]&0xE))  << 29;
 168                         pts |= ((unsigned long long)(payload[10]&0xFF)) << 22;
 169                         pts |= ((unsigned long long)(payload[11]&0xFE)) << 14;
 170                         pts |= ((unsigned long long)(payload[12]&0xFF)) << 7;
 171                         pts |= ((unsigned long long)(payload[13]&0xFE)) >> 1;
 172                         offset -= 188;
 173
 174 //                      eDebug("found pts %08llx at %08llx pid %02x stream: %02x", pts, offset, pid, payload[3]);
 175
 176                                 /* convert to zero-based */
 177                         if (fixed && fixupPTS(offset, pts))
 178                                         return -1;
 179                         return 0;
 180                 }
 181         }
 182
 183         return -1;
 184 }
 185
 186 int eDVBTSTools::fixupPTS(const off_t &offset, pts_t &now)
 187 {
 188         if (m_use_streaminfo)
 189         {
 190                 if (!m_streaminfo.fixupPTS(offset, now))
 191                         return 0;
 192         } else
 193         {
 194                         /* for the simple case, we assume one epoch, with up to one wrap around in the middle. */
 195                 calcBegin();
 196                 if (!m_begin_valid)
 197                 {
 198                         eDebug("begin not valid, can't fixup");
 199                         return -1;
 200                 }
 201
 202                 pts_t pos = m_pts_begin;
 203                 if ((now < pos) && ((pos - now) < 90000 * 10))
 204                 {
 205                         pos = 0;
 206                         return 0;
 207                 }
 208
 209                 if (now < pos) /* wrap around */
 210                         now = now + 0x200000000LL - pos;
 211                 else
 212                         now -= pos;
 213                 return 0;
 214         }
 215 }
 216
 217 int eDVBTSTools::getOffset(off_t &offset, pts_t &pts, int marg)
 218 {
 219         if (m_use_streaminfo)
 220         {
 221                 if (pts >= m_pts_end && marg > 0 && m_end_valid)
 222                         offset = m_offset_end;
 223                 else
 224                         offset = m_streaminfo.getAccessPoint(pts, marg);
 225                 return 0;
 226         } else
 227         {
 228                 calcBegin(); calcEnd();
 229
 230                 if (!m_begin_valid)
 231                         return -1;
 232                 if (!m_end_valid)
 233                         return -1;
 234
 235                 if (!m_samples_taken)
 236                         takeSamples();
 237
 238                 if (!m_samples.empty())
 239                 {
 240                         int maxtries = 5;
 241                         pts_t p = -1;
 242
 243                         while (maxtries--)
 244                         {
 245                                         /* search entry before and after */
 246                                 std::map<pts_t, off_t>::const_iterator l = m_samples.lower_bound(pts);
 247                                 std::map<pts_t, off_t>::const_iterator u = l;
 248
 249                                 if (l != m_samples.begin())
 250                                         --l;
 251
 252                                         /* we could have seeked beyond the end */
 253                                 if (u == m_samples.end())
 254                                 {
 255                                                 /* use last segment for interpolation. */
 256                                         if (l != m_samples.begin())
 257                                         {
 258                                                 --u;
 259                                                 --l;
 260                                         }
 261                                 }
 262
 263                                         /* if we don't have enough points */
 264                                 if (u == m_samples.end())
 265                                         break;
 266
 267                                 pts_t pts_diff = u->first - l->first;
 268                                 off_t offset_diff = u->second - l->second;
 269
 270                                 if (offset_diff < 0)
 271                                 {
 272                                         eDebug("something went wrong when taking samples.");
 273                                         m_samples.clear();
 274                                         takeSamples();
 275                                         continue;
 276                                 }
 277
 278                                 eDebug("using: %llx:%llx -> %llx:%llx", l->first, u->first, l->second, u->second);
 279
 280                                 int bitrate;
 281
 282                                 if (pts_diff)
 283                                         bitrate = offset_diff * 90000 * 8 / pts_diff;
 284                                 else
 285                                         bitrate = 0;
 286
 287                                 offset = l->second;
 288                                 offset += ((pts - l->first) * (pts_t)bitrate) / 8ULL / 90000ULL;
 289                                 offset -= offset % 188;
 290
 291                                 p = pts;
 292
 293                                 if (!takeSample(offset, p))
 294                                 {
 295                                         int diff = (p - pts) / 90;
 296
 297                                         eDebug("calculated diff %d ms", diff);
 298                                         if (abs(diff) > 300)
 299                                         {
 300                                                 eDebug("diff to big, refining");
 301                                                 continue;
 302                                         }
 303                                 } else
 304                                         eDebug("no sample taken, refinement not possible.");
 305
 306                                 break;
 307                         }
 308
 309                                 /* if even the first sample couldn't be taken, fall back. */
 310                                 /* otherwise, return most refined result. */
 311                         if (p != -1)
 312                         {
 313                                 pts = p;
 314                                 eDebug("aborting. Taking %llx as offset for %lld", offset, pts);
 315                                 return 0;
 316                         }
 317                 }
 318
 319                 int bitrate = calcBitrate();
 320                 offset = pts * (pts_t)bitrate / 8ULL / 90000ULL;
 321                 eDebug("fallback, bitrate=%d, results in %016llx", bitrate, offset);
 322                 offset -= offset % 188;
 323
 324                 return 0;
 325         }
 326 }
 327
 328 int eDVBTSTools::getNextAccessPoint(pts_t &ts, const pts_t &start, int direction)
 329 {
 330         if (m_use_streaminfo)
 331                 return m_streaminfo.getNextAccessPoint(ts, start, direction);
 332         else
 333         {
 334                 eDebug("can't get next access point without streaminfo");
 335                 return -1;
 336         }
 337 }
 338
 339 void eDVBTSTools::calcBegin()
 340 {
 341         if (!m_file.valid())
 342                 return;
 343
 344         if (!(m_begin_valid || m_futile))
 345         {
 346                 m_offset_begin = 0;
 347                 if (!getPTS(m_offset_begin, m_pts_begin))
 348                         m_begin_valid = 1;
 349                 else
 350                         m_futile = 1;
 351         }
 352 }
 353
 354 void eDVBTSTools::calcEnd()
 355 {
 356         if (!m_file.valid())
 357                 return;
 358
 359         off_t end = m_file.lseek(0, SEEK_END);
 360
 361         if (llabs(end - m_last_filelength) > 1*1024*1024)
 362         {
 363                 m_last_filelength = end;
 364                 m_end_valid = 0;
 365
 366                 m_futile = 0;
 367 //              eDebug("file size changed, recalc length");
 368         }
 369
 370         int maxiter = 10;
 371
 372         m_offset_end = m_last_filelength;
 373
 374         while (!(m_end_valid || m_futile))
 375         {
 376                 if (!--maxiter)
 377                 {
 378                         m_futile = 1;
 379                         return;
 380                 }
 381
 382                 m_offset_end -= m_maxrange;
 383                 if (m_offset_end < 0)
 384                         m_offset_end = 0;
 385
 386                         /* restore offset if getpts fails */
 387                 off_t off = m_offset_end;
 388
 389                 if (!getPTS(m_offset_end, m_pts_end))
 390                         m_end_valid = 1;
 391                 else
 392                         m_offset_end = off;
 393
 394                 if (!m_offset_end)
 395                 {
 396                         m_futile = 1;
 397                         break;
 398                 }
 399         }
 400 }
 401
 402 int eDVBTSTools::calcLen(pts_t &len)
 403 {
 404         calcBegin(); calcEnd();
 405         if (!(m_begin_valid && m_end_valid))
 406                 return -1;
 407         len = m_pts_end - m_pts_begin;
 408                 /* wrap around? */
 409         if (len < 0)
 410                 len += 0x200000000LL;
 411         return 0;
 412 }
 413
 414 int eDVBTSTools::calcBitrate()
 415 {
 416         calcBegin(); calcEnd();
 417         if (!(m_begin_valid && m_end_valid))
 418                 return -1;
 419
 420         pts_t len_in_pts = m_pts_end - m_pts_begin;
 421
 422                 /* wrap around? */
 423         if (len_in_pts < 0)
 424                 len_in_pts += 0x200000000LL;
 425         off_t len_in_bytes = m_offset_end - m_offset_begin;
 426
 427         if (!len_in_pts)
 428                 return -1;
 429
 430         unsigned long long bitrate = len_in_bytes * 90000 * 8 / len_in_pts;
 431         if ((bitrate < 10000) || (bitrate > 100000000))
 432                 return -1;
 433
 434         return bitrate;
 435 }
 436
 437         /* pts, off */
 438 void eDVBTSTools::takeSamples()
 439 {
 440         m_samples_taken = 1;
 441         m_samples.clear();
 442         pts_t dummy;
 443         if (calcLen(dummy) == -1)
 444                 return;
 445
 446         int nr_samples = 30;
 447         off_t bytes_per_sample = (m_offset_end - m_offset_begin) / (long long)nr_samples;
 448         if (bytes_per_sample < 40*1024*1024)
 449                 bytes_per_sample = 40*1024*1024;
 450
 451         bytes_per_sample -= bytes_per_sample % 188;
 452
 453         for (off_t offset = m_offset_begin; offset < m_offset_end; offset += bytes_per_sample)
 454         {
 455                 pts_t p;
 456                 takeSample(offset, p);
 457         }
 458         m_samples[0] = m_offset_begin;
 459         m_samples[m_pts_end - m_pts_begin] = m_offset_end;
 460
 461 //      eDebug("begin, end: %llx %llx", m_offset_begin, m_offset_end);
 462 }
 463
 464         /* returns 0 when a sample was taken. */
 465 int eDVBTSTools::takeSample(off_t off, pts_t &p)
 466 {
 467         if (!eDVBTSTools::getPTS(off, p, 1))
 468         {
 469                         /* as we are happily mixing PTS and PCR values (no comment, please), we might
 470                            end up with some "negative" segments.
 471
 472                            so check if this new sample is between the previous and the next field*/
 473
 474                 std::map<pts_t, off_t>::const_iterator l = m_samples.lower_bound(p);
 475                 std::map<pts_t, off_t>::const_iterator u = l;
 476
 477                 if (l != m_samples.begin())
 478                 {
 479                         --l;
 480                         if (u != m_samples.end())
 481                         {
 482                                 if ((l->second > off) || (u->second < off))
 483                                 {
 484                                         eDebug("ignoring sample %llx %llx %llx (%lld %lld %lld)",
 485                                                 l->second, off, u->second, l->first, p, u->first);
 486                                         return 1;
 487                                 }
 488                         }
 489                 }
 490
 491
 492                 m_samples[p] = off;
 493                 return 0;
 494         }
 495         return 1;
 496 }
 497
 498 int eDVBTSTools::findPMT(int &pmt_pid, int &service_id)
 499 {
 500                 /* FIXME: this will be factored out soon! */
 501         if (!m_file.valid())
 502         {
 503                 eDebug(" file not valid");
 504                 return -1;
 505         }
 506
 507         if (m_file.lseek(0, SEEK_SET) < 0)
 508         {
 509                 eDebug("seek failed");
 510                 return -1;
 511         }
 512
 513         int left = 5*1024*1024;
 514
 515         while (left >= 188)
 516         {
 517                 unsigned char packet[188];
 518                 if (m_file.read(packet, 188) != 188)
 519                 {
 520                         eDebug("read error");
 521                         break;
 522                 }
 523                 left -= 188;
 524
 525                 if (packet[0] != 0x47)
 526                 {
 527                         int i = 0;
 528                         while (i < 188)
 529                         {
 530                                 if (packet[i] == 0x47)
 531                                         break;
 532                                 ++i;
 533                         }
 534                         m_file.lseek(i - 188, SEEK_CUR);
 535                         continue;
 536                 }
 537
 538                 int pid = ((packet[1] << 8) | packet[2]) & 0x1FFF;
 539
 540                 int pusi = !!(packet[1] & 0x40);
 541
 542                 if (!pusi)
 543                         continue;
 544
 545                         /* ok, now we have a PES header or section header*/
 546                 unsigned char *sec;
 547
 548                         /* check for adaption field */
 549                 if (packet[3] & 0x20)
 550                 {
 551                         if (packet[4] >= 183)
 552                                 continue;
 553                         sec = packet + packet[4] + 4 + 1;
 554                 } else
 555                         sec = packet + 4;
 556
 557                 if (sec[0])     /* table pointer, assumed to be 0 */
 558                         continue;
 559
 560                 if (sec[1] == 0x02) /* program map section */
 561                 {
 562                         pmt_pid = pid;
 563                         service_id = (sec[4] << 8) | sec[5];
 564                         return 0;
 565                 }
 566         }
 567
 568         return -1;
 569 }
 570
 571 int eDVBTSTools::findFrame(off_t &_offset, size_t &len, int &direction, int frame_types)
 572 {
 573         off_t offset = _offset;
 574         int nr_frames = 0;
 575 //      eDebug("trying to find iFrame at %llx", offset);
 576
 577         if (!m_use_streaminfo)
 578         {
 579 //              eDebug("can't get next iframe without streaminfo");
 580                 return -1;
 581         }
 582
 583                                 /* let's find the iframe before the given offset */
 584         unsigned long long data;
 585
 586         if (direction < 0)
 587                 offset--;
 588
 589         while (1)
 590         {
 591                 if (m_streaminfo.getStructureEntry(offset, data, (direction == 0) ? 1 : 0))
 592                 {
 593                         eDebug("getting structure info for origin offset failed.");
 594                         return -1;
 595                 }
 596                 if (offset == 0x7fffffffffffffffLL) /* eof */
 597                 {
 598                         eDebug("reached eof");
 599                         return -1;
 600                 }
 601                         /* data is usually the start code in the lower 8 bit, and the next byte <<8. we extract the picture type from there */
 602                         /* we know that we aren't recording startcode 0x09 for mpeg2, so this is safe */
 603                         /* TODO: check frame_types */
 604                 int is_start = (data & 0xE0FF) == 0x0009; /* H.264 NAL unit access delimiter with I-frame*/
 605                 is_start |= (data & 0x3800FF) == 0x080000; /* MPEG2 picture start code with I-frame */
 606
 607                 int is_frame = ((data & 0xFF) == 0x0009) || ((data & 0xFF) == 0x00); /* H.264 UAD or MPEG2 start code */
 608
 609                 if (is_frame)
 610                 {
 611                         if (direction < 0)
 612                                 --nr_frames;
 613                         else
 614                                 ++nr_frames;
 615                 }
 616 //              eDebug("%08llx@%llx -> %d, %d", data, offset, is_start, nr_frames);
 617                 if (is_start)
 618                         break;
 619
 620                 if (direction == -1)
 621                         --offset; /* move to previous entry */
 622                 else if (direction == +1)
 623                         direction = 0;
 624         }
 625                         /* let's find the next frame after the given offset */
 626         off_t start = offset;
 627
 628         do {
 629                 if (m_streaminfo.getStructureEntry(offset, data, 1))
 630                 {
 631                         eDebug("get next failed");
 632                         return -1;
 633                 }
 634                 if (offset == 0x7fffffffffffffffLL) /* eof */
 635                 {
 636                         eDebug("reached eof (while looking for end of iframe)");
 637                         return -1;
 638                 }
 639 //              eDebug("%08llx@%llx (next)", data, offset);
 640         } while (((data & 0xFF) != 9) && ((data & 0xFF) != 0x00)); /* next frame */
 641
 642                         /* align to TS pkt start */
 643 //      start = start - (start % 188);
 644 //      offset = offset - (offset % 188);
 645
 646         len = offset - start;
 647         _offset = start;
 648         direction = nr_frames;
 649 //      eDebug("result: offset=%llx, len: %ld", offset, (int)len);
 650         return 0;
 651 }
 652
 653 int eDVBTSTools::findNextPicture(off_t &offset, size_t &len, int &distance, int frame_types)
 654 {
 655         int nr_frames, direction;
 656 //      eDebug("trying to move %d frames at %llx", distance, offset);
 657
 658         frame_types = frametypeI; /* TODO: intelligent "allow IP frames when not crossing an I-Frame */
 659
 660         off_t new_offset = offset;
 661         size_t new_len = len;
 662         int first = 1;
 663
 664         if (distance > 0) {
 665                 direction = 0;
 666                 nr_frames = 0;
 667         } else {
 668                 direction = -1;
 669                 nr_frames = -1;
 670                 distance = -distance+1;
 671         }
 672         while (distance > 0)
 673         {
 674                 int dir = direction;
 675                 if (findFrame(new_offset, new_len, dir, frame_types))
 676                 {
 677 //                      eDebug("findFrame failed!\n");
 678                         return -1;
 679                 }
 680
 681                 distance -= abs(dir);
 682
 683 //              eDebug("we moved %d, %d to go frames (now at %llx)", dir, distance, new_offset);
 684
 685                 if (distance >= 0 || direction == 0)
 686                 {
 687                         first = 0;
 688                         offset = new_offset;
 689                         len = new_len;
 690                         nr_frames += abs(dir);
 691                 }
 692                 else if (first) {
 693                         first = 0;
 694                         offset = new_offset;
 695                         len = new_len;
 696                         nr_frames += abs(dir) + distance; // never jump forward during rewind
 697                 }
 698         }
 699
 700         distance = (direction < 0) ? -nr_frames : nr_frames;
 701 //      eDebug("in total, we moved %d frames", nr_frames);
 702
 703         return 0;
 704 }