lib/dvb/tstools.cpp

   1 #include <lib/dvb/tstools.h>
   2 #include <lib/base/eerror.h>
   3 #include <unistd.h>
   4 #include <fcntl.h>
   5
   6 #include <stdio.h>
   7
   8 eDVBTSTools::eDVBTSTools()
   9 {
  10         m_pid = -1;
  11         m_maxrange = 256*1024;
  12
  13         m_begin_valid = 0;
  14         m_end_valid = 0;
  15
  16         m_use_streaminfo = 0;
  17         m_samples_taken = 0;
  18
  19         m_last_filelength = 0;
  20
  21         m_futile = 0;
  22 }
  23
  24 eDVBTSTools::~eDVBTSTools()
  25 {
  26         closeFile();
  27 }
  28
  29 int eDVBTSTools::openFile(const char *filename, int nostreaminfo)
  30 {
  31         closeFile();
  32
  33         if (!nostreaminfo)
  34                 m_streaminfo.load((std::string(filename) + ".ap").c_str());
  35
  36         if (!m_streaminfo.empty())
  37                 m_use_streaminfo = 1;
  38         else
  39         {
  40 //              eDebug("no recorded stream information available");
  41                 m_use_streaminfo = 0;
  42         }
  43
  44         m_samples_taken = 0;
  45
  46         if (m_file.open(filename, 1) < 0)
  47                 return -1;
  48         return 0;
  49 }
  50
  51 void eDVBTSTools::closeFile()
  52 {
  53         m_file.close();
  54 }
  55
  56 void eDVBTSTools::setSyncPID(int pid)
  57 {
  58         m_pid = pid;
  59 }
  60
  61 void eDVBTSTools::setSearchRange(int maxrange)
  62 {
  63         m_maxrange = maxrange;
  64 }
  65
  66         /* getPTS extracts a pts value from any PID at a given offset. */
  67 int eDVBTSTools::getPTS(off_t &offset, pts_t &pts, int fixed)
  68 {
  69         if (m_use_streaminfo)
  70                 return m_streaminfo.getPTS(offset, pts);
  71
  72         if (!m_file.valid())
  73                 return -1;
  74
  75         offset -= offset % 188;
  76
  77         if (m_file.lseek(offset, SEEK_SET) < 0)
  78                 return -1;
  79
  80         int left = m_maxrange;
  81
  82         while (left >= 188)
  83         {
  84                 unsigned char packet[188];
  85                 if (m_file.read(packet, 188) != 188)
  86                 {
  87                         eDebug("read error");
  88                         break;
  89                 }
  90                 left -= 188;
  91                 offset += 188;
  92
  93                 if (packet[0] != 0x47)
  94                 {
  95                         int i = 0;
  96                         while (i < 188)
  97                         {
  98                                 if (packet[i] == 0x47)
  99                                         break;
 100                                 ++i;
 101                         }
 102                         offset = m_file.lseek(i - 188, SEEK_CUR);
 103                         continue;
 104                 }
 105
 106                 int pid = ((packet[1] << 8) | packet[2]) & 0x1FFF;
 107                 int pusi = !!(packet[1] & 0x40);
 108
 109 //              printf("PID %04x, PUSI %d\n", pid, pusi);
 110
 111                 unsigned char *payload;
 112
 113                         /* check for adaption field */
 114                 if (packet[3] & 0x20)
 115                 {
 116                         if (packet[4] >= 183)
 117                                 continue;
 118                         if (packet[4])
 119                         {
 120                                 if (packet[5] & 0x10) /* PCR present */
 121                                 {
 122                                         pts  = ((unsigned long long)(packet[ 6]&0xFF)) << 25;
 123                                         pts |= ((unsigned long long)(packet[ 7]&0xFF)) << 17;
 124                                         pts |= ((unsigned long long)(packet[ 8]&0xFE)) << 9;
 125                                         pts |= ((unsigned long long)(packet[ 9]&0xFF)) << 1;
 126                                         pts |= ((unsigned long long)(packet[10]&0x80)) >> 7;
 127                                         offset -= 188;
 128                                         eDebug("PCR  found: %16llx", pts);
 129                                         if (fixed && fixupPTS(offset, pts))
 130                                                 return -1;
 131                                         return 0;
 132                                 }
 133                         }
 134                         payload = packet + packet[4] + 4 + 1;
 135                 } else
 136                         payload = packet + 4;
 137
 138
 139                 if (m_pid >= 0)
 140                         if (pid != m_pid)
 141                                 continue;
 142                 if (!pusi)
 143                         continue;
 144
 145
 146                         /* somehow not a startcode. (this is invalid, since pusi was set.) ignore it. */
 147                 if (payload[0] || payload[1] || (payload[2] != 1))
 148                         continue;
 149
 150                         /* drop non-audio, non-video packets because other streams
 151                            can be non-compliant.*/
 152                 if (((payload[3] & 0xE0) != 0xC0) &&  // audio
 153                     ((payload[3] & 0xF0) != 0xE0))    // video
 154                         continue;
 155
 156                 if (payload[7] & 0x80) /* PTS */
 157                 {
 158                         pts  = ((unsigned long long)(payload[ 9]&0xE))  << 29;
 159                         pts |= ((unsigned long long)(payload[10]&0xFF)) << 22;
 160                         pts |= ((unsigned long long)(payload[11]&0xFE)) << 14;
 161                         pts |= ((unsigned long long)(payload[12]&0xFF)) << 7;
 162                         pts |= ((unsigned long long)(payload[13]&0xFE)) >> 1;
 163                         offset -= 188;
 164
 165                         eDebug("found pts %08llx at %08llx pid %02x stream: %02x", pts, offset, pid, payload[3]);
 166
 167                                 /* convert to zero-based */
 168                         if (fixed && fixupPTS(offset, pts))
 169                                         return -1;
 170                         return 0;
 171                 }
 172         }
 173
 174         return -1;
 175 }
 176
 177 int eDVBTSTools::fixupPTS(const off_t &offset, pts_t &now)
 178 {
 179         if (m_use_streaminfo)
 180         {
 181                 return m_streaminfo.fixupPTS(offset, now);
 182         } else
 183         {
 184                         /* for the simple case, we assume one epoch, with up to one wrap around in the middle. */
 185                 calcBegin();
 186                 if (!m_begin_valid)
 187                 {
 188                         eDebug("begin not valid, can't fixup");
 189                         return -1;
 190                 }
 191
 192                 pts_t pos = m_pts_begin;
 193                 if ((now < pos) && ((pos - now) < 90000 * 10))
 194                 {
 195                         pos = 0;
 196                         return 0;
 197                 }
 198
 199                 if (now < pos) /* wrap around */
 200                         now = now + 0x200000000LL - pos;
 201                 else
 202                         now -= pos;
 203                 return 0;
 204         }
 205 }
 206
 207 int eDVBTSTools::getOffset(off_t &offset, pts_t &pts)
 208 {
 209         if (m_use_streaminfo)
 210         {
 211                 offset = m_streaminfo.getAccessPoint(pts);
 212                 return 0;
 213         } else
 214         {
 215                 eDebug("get offset: pts=%llx", pts);
 216                 calcBegin(); calcEnd();
 217
 218                 if (!m_begin_valid)
 219                         return -1;
 220                 if (!m_end_valid)
 221                         return -1;
 222
 223                 if (!m_samples_taken)
 224                         takeSamples();
 225
 226                 if (!m_samples.empty())
 227                 {
 228                         int maxtries = 5;
 229                         pts_t p = -1;
 230
 231                         while (maxtries--)
 232                         {
 233                                         /* search entry before and after */
 234                                 std::map<pts_t, off_t>::const_iterator l = m_samples.lower_bound(pts);
 235                                 std::map<pts_t, off_t>::const_iterator u = l;
 236
 237                                 if (l != m_samples.begin())
 238                                         --l;
 239
 240                                         /* we could have seeked beyond the end */
 241                                 if (u == m_samples.end())
 242                                 {
 243                                                 /* use last segment for interpolation. */
 244                                         if (l != m_samples.begin())
 245                                         {
 246                                                 --u;
 247                                                 --l;
 248                                         }
 249                                 }
 250
 251                                         /* if we don't have enough points */
 252                                 if (u == m_samples.end())
 253                                         break;
 254
 255                                 pts_t pts_diff = u->first - l->first;
 256                                 off_t offset_diff = u->second - l->second;
 257
 258                                 eDebug("using: %llx:%llx -> %llx:%llx", l->first, u->first, l->second, u->second);
 259
 260                                 int bitrate;
 261
 262                                 if (pts_diff)
 263                                         bitrate = offset_diff * 90000 * 8 / pts_diff;
 264                                 else
 265                                         bitrate = 0;
 266
 267                                 offset = l->second;
 268                                 offset += ((pts - l->first) * (pts_t)bitrate) / 8ULL / 90000ULL;
 269                                 offset -= offset % 188;
 270
 271                                 p = pts;
 272
 273                                 eDebug("so next guess at %llx", offset);
 274
 275                                 if (!takeSample(offset, p))
 276                                 {
 277                                         int diff = (p - pts) / 90;
 278
 279                                         eDebug("calculated diff %d ms", diff);
 280                                         if (abs(diff) > 300)
 281                                         {
 282                                                 eDebug("diff to big, refining");
 283                                                 continue;
 284                                         }
 285                                 } else
 286                                         eDebug("no sample taken, refinement not possible.");
 287
 288                                 break;
 289                         }
 290
 291                                 /* if even the first sample couldn't be taken, fall back. */
 292                                 /* otherwise, return most refined result. */
 293                         if (p != -1)
 294                         {
 295                                 pts = p;
 296                                 return 0;
 297                         }
 298                 }
 299
 300                 eDebug("falling back");
 301                 int bitrate = calcBitrate();
 302                 offset = pts * (pts_t)bitrate / 8ULL / 90000ULL;
 303                 offset -= offset % 188;
 304
 305                 return 0;
 306         }
 307 }
 308
 309 int eDVBTSTools::getNextAccessPoint(pts_t &ts, const pts_t &start, int direction)
 310 {
 311         if (m_use_streaminfo)
 312                 return m_streaminfo.getNextAccessPoint(ts, start, direction);
 313         else
 314         {
 315                 eDebug("can't get next access point without streaminfo");
 316                 return -1;
 317         }
 318 }
 319
 320 void eDVBTSTools::calcBegin()
 321 {
 322         if (!m_file.valid())
 323                 return;
 324
 325         if (!(m_begin_valid || m_futile))
 326         {
 327                 m_offset_begin = 0;
 328                 if (!getPTS(m_offset_begin, m_pts_begin))
 329                         m_begin_valid = 1;
 330                 else
 331                         m_futile = 1;
 332         }
 333 }
 334
 335 void eDVBTSTools::calcEnd()
 336 {
 337         if (!m_file.valid())
 338                 return;
 339
 340         off_t end = m_file.lseek(0, SEEK_END);
 341
 342         if (abs(end - m_last_filelength) > 1*1024*1024)
 343         {
 344                 m_last_filelength = end;
 345                 m_end_valid = 0;
 346
 347                 m_futile = 0;
 348 //              eDebug("file size changed, recalc length");
 349         }
 350
 351         int maxiter = 10;
 352
 353         m_offset_end = m_last_filelength;
 354
 355         while (!(m_end_valid || m_futile))
 356         {
 357                 if (!--maxiter)
 358                 {
 359                         m_futile = 1;
 360                         return;
 361                 }
 362
 363                 m_offset_end -= m_maxrange;
 364                 if (m_offset_end < 0)
 365                         m_offset_end = 0;
 366
 367                         /* restore offset if getpts fails */
 368                 off_t off = m_offset_end;
 369
 370                 if (!getPTS(m_offset_end, m_pts_end))
 371                         m_end_valid = 1;
 372                 else
 373                         m_offset_end = off;
 374
 375                 if (!m_offset_end)
 376                 {
 377                         m_futile = 1;
 378                         break;
 379                 }
 380         }
 381 }
 382
 383 int eDVBTSTools::calcLen(pts_t &len)
 384 {
 385         calcBegin(); calcEnd();
 386         if (!(m_begin_valid && m_end_valid))
 387                 return -1;
 388         len = m_pts_end - m_pts_begin;
 389                 /* wrap around? */
 390         if (len < 0)
 391                 len += 0x200000000LL;
 392         return 0;
 393 }
 394
 395 int eDVBTSTools::calcBitrate()
 396 {
 397         calcBegin(); calcEnd();
 398         if (!(m_begin_valid && m_end_valid))
 399                 return -1;
 400
 401         pts_t len_in_pts = m_pts_end - m_pts_begin;
 402
 403                 /* wrap around? */
 404         if (len_in_pts < 0)
 405                 len_in_pts += 0x200000000LL;
 406         off_t len_in_bytes = m_offset_end - m_offset_begin;
 407
 408         if (!len_in_pts)
 409                 return -1;
 410
 411         unsigned long long bitrate = len_in_bytes * 90000 * 8 / len_in_pts;
 412         if ((bitrate < 10000) || (bitrate > 100000000))
 413                 return -1;
 414
 415         return bitrate;
 416 }
 417
 418         /* pts, off */
 419 void eDVBTSTools::takeSamples()
 420 {
 421         m_samples_taken = 1;
 422         m_samples.clear();
 423         pts_t dummy;
 424         if (calcLen(dummy) == -1)
 425                 return;
 426
 427         int nr_samples = 30;
 428         off_t bytes_per_sample = (m_offset_end - m_offset_begin) / (long long)nr_samples;
 429         if (bytes_per_sample < 40*1024*1024)
 430                 bytes_per_sample = 40*1024*1024;
 431
 432         bytes_per_sample -= bytes_per_sample % 188;
 433
 434         for (off_t offset = m_offset_begin; offset < m_offset_end; offset += bytes_per_sample)
 435         {
 436                 pts_t p;
 437                 takeSample(offset, p);
 438         }
 439         m_samples[0] = m_offset_begin;
 440         m_samples[m_pts_end - m_pts_begin] = m_offset_end;
 441
 442 //      eDebug("begin, end: %llx %llx", m_offset_begin, m_offset_end);
 443 }
 444
 445         /* returns 0 when a sample was taken. */
 446 int eDVBTSTools::takeSample(off_t off, pts_t &p)
 447 {
 448         eDebug("take sample: %llx", off);
 449         if (!eDVBTSTools::getPTS(off, p, 1))
 450         {
 451                 eDebug("took sample: %llx, %llx", off, p);
 452                 m_samples[p] = off;
 453                 return 0;
 454         }
 455         return 1;
 456 }
 457
 458 int eDVBTSTools::findPMT(int &pmt_pid, int &service_id)
 459 {
 460                 /* FIXME: this will be factored out soon! */
 461         if (!m_file.valid())
 462         {
 463                 eDebug(" file not valid");
 464                 return -1;
 465         }
 466
 467         if (m_file.lseek(0, SEEK_SET) < 0)
 468         {
 469                 eDebug("seek failed");
 470                 return -1;
 471         }
 472
 473         int left = 5*1024*1024;
 474
 475         while (left >= 188)
 476         {
 477                 unsigned char packet[188];
 478                 if (m_file.read(packet, 188) != 188)
 479                 {
 480                         eDebug("read error");
 481                         break;
 482                 }
 483                 left -= 188;
 484
 485                 if (packet[0] != 0x47)
 486                 {
 487                         int i = 0;
 488                         while (i < 188)
 489                         {
 490                                 if (packet[i] == 0x47)
 491                                         break;
 492                                 ++i;
 493                         }
 494                         m_file.lseek(i - 188, SEEK_CUR);
 495                         continue;
 496                 }
 497
 498                 int pid = ((packet[1] << 8) | packet[2]) & 0x1FFF;
 499
 500                 int pusi = !!(packet[1] & 0x40);
 501
 502                 if (!pusi)
 503                         continue;
 504
 505                         /* ok, now we have a PES header or section header*/
 506                 unsigned char *sec;
 507
 508                         /* check for adaption field */
 509                 if (packet[3] & 0x20)
 510                 {
 511                         if (packet[4] >= 183)
 512                                 continue;
 513                         sec = packet + packet[4] + 4 + 1;
 514                 } else
 515                         sec = packet + 4;
 516
 517                 if (sec[0])     /* table pointer, assumed to be 0 */
 518                         continue;
 519
 520                 if (sec[1] == 0x02) /* program map section */
 521                 {
 522                         pmt_pid = pid;
 523                         service_id = (sec[4] << 8) | sec[5];
 524                         return 0;
 525                 }
 526         }
 527
 528         return -1;
 529 }