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