libavformat/mpeg.c

   1 /*
   2  * MPEG-1/2 demuxer
   3  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavutil/channel_layout.h"
  23 #include "avformat.h"
  24 #include "avio_internal.h"
  25 #include "internal.h"
  26 #include "mpeg.h"
  27
  28 /*********************************************/
  29 /* demux code */
  30
  31 #define MAX_SYNC_SIZE 100000
  32
  33 static int check_pes(const uint8_t *p, const uint8_t *end)
  34 {
  35     int pes1;
  36     int pes2 = (p[3] & 0xC0) == 0x80 &&
  37                (p[4] & 0xC0) != 0x40 &&
  38                ((p[4] & 0xC0) == 0x00 ||
  39                 (p[4] & 0xC0) >> 2 == (p[6] & 0xF0));
  40
  41     for (p += 3; p < end && *p == 0xFF; p++) ;
  42     if ((*p & 0xC0) == 0x40)
  43         p += 2;
  44
  45     if ((*p & 0xF0) == 0x20)
  46         pes1 = p[0] & p[2] & p[4] & 1;
  47     else if ((*p & 0xF0) == 0x30)
  48         pes1 = p[0] & p[2] & p[4] & p[5] & p[7] & p[9] & 1;
  49     else
  50         pes1 = *p == 0x0F;
  51
  52     return pes1 || pes2;
  53 }
  54
  55 static int check_pack_header(const uint8_t *buf)
  56 {
  57     return (buf[1] & 0xC0) == 0x40 || (buf[1] & 0xF0) == 0x20;
  58 }
  59
  60 static int mpegps_probe(const AVProbeData *p)
  61 {
  62     uint32_t code = -1;
  63     int i;
  64     int sys = 0, pspack = 0, priv1 = 0, vid = 0;
  65     int audio = 0, invalid = 0, score = 0;
  66     int endpes = 0;
  67
  68     for (i = 0; i < p->buf_size; i++) {
  69         code = (code << 8) + p->buf[i];
  70         if ((code & 0xffffff00) == 0x100) {
  71             int len  = p->buf[i + 1] << 8 | p->buf[i + 2];
  72             int pes  = endpes <= i && check_pes(p->buf + i, p->buf + p->buf_size);
  73             int pack = check_pack_header(p->buf + i);
  74
  75             if (code == SYSTEM_HEADER_START_CODE)
  76                 sys++;
  77             else if (code == PACK_START_CODE && pack)
  78                 pspack++;
  79             else if ((code & 0xf0) == VIDEO_ID && pes) {
  80                 endpes = i + len;
  81                 vid++;
  82             }
  83             // skip pes payload to avoid start code emulation for private
  84             // and audio streams
  85             else if ((code & 0xe0) == AUDIO_ID &&  pes) {audio++; i+=len;}
  86             else if (code == PRIVATE_STREAM_1  &&  pes) {priv1++; i+=len;}
  87             else if (code == 0x1fd             &&  pes) vid++; //VC1
  88
  89             else if ((code & 0xf0) == VIDEO_ID && !pes) invalid++;
  90             else if ((code & 0xe0) == AUDIO_ID && !pes) invalid++;
  91             else if (code == PRIVATE_STREAM_1  && !pes) invalid++;
  92         }
  93     }
  94
  95     if (vid + audio > invalid + 1) /* invalid VDR files nd short PES streams */
  96         score = AVPROBE_SCORE_EXTENSION / 2;
  97
  98 //     av_log(NULL, AV_LOG_ERROR, "vid:%d aud:%d sys:%d pspack:%d invalid:%d size:%d \n",
  99 //            vid, audio, sys, pspack, invalid, p->buf_size);
 100
 101     if (sys > invalid && sys * 9 <= pspack * 10)
 102         return (audio > 12 || vid > 3 || pspack > 2) ? AVPROBE_SCORE_EXTENSION + 2
 103                                                      : AVPROBE_SCORE_EXTENSION / 2 + (audio + vid + pspack > 1); // 1 more than mp3
 104     if (pspack > invalid && (priv1 + vid + audio) * 10 >= pspack * 9)
 105         return pspack > 2 ? AVPROBE_SCORE_EXTENSION + 2
 106                           : AVPROBE_SCORE_EXTENSION / 2; // 1 more than .mpg
 107     if ((!!vid ^ !!audio) && (audio > 4 || vid > 1) && !sys &&
 108         !pspack && p->buf_size > 2048 && vid + audio > invalid) /* PES stream */
 109         return (audio > 12 || vid > 6 + 2 * invalid) ? AVPROBE_SCORE_EXTENSION + 2
 110                                                      : AVPROBE_SCORE_EXTENSION / 2;
 111
 112     // 02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1
 113     // mp3_misidentified_2.mp3 has sys:0 priv1:0 pspack:0 vid:0 audio:6
 114     // Have\ Yourself\ a\ Merry\ Little\ Christmas.mp3 0 0 0 5 0 1 len:21618
 115     return score;
 116 }
 117
 118 typedef struct MpegDemuxContext {
 119     int32_t header_state;
 120     unsigned char psm_es_type[256];
 121     int sofdec;
 122     int dvd;
 123     int imkh_cctv;
 124     int raw_ac3;
 125 } MpegDemuxContext;
 126
 127 static int mpegps_read_header(AVFormatContext *s)
 128 {
 129     MpegDemuxContext *m = s->priv_data;
 130     char buffer[7] = { 0 };
 131     int64_t last_pos = avio_tell(s->pb);
 132
 133     m->header_state = 0xff;
 134     s->ctx_flags   |= AVFMTCTX_NOHEADER;
 135
 136     avio_get_str(s->pb, 6, buffer, sizeof(buffer));
 137     if (!memcmp("IMKH", buffer, 4)) {
 138         m->imkh_cctv = 1;
 139     } else if (!memcmp("Sofdec", buffer, 6)) {
 140         m->sofdec = 1;
 141     } else
 142        avio_seek(s->pb, last_pos, SEEK_SET);
 143
 144     /* no need to do more */
 145     return 0;
 146 }
 147
 148 static int64_t get_pts(AVIOContext *pb, int c)
 149 {
 150     uint8_t buf[5];
 151     int ret;
 152
 153     buf[0] = c < 0 ? avio_r8(pb) : c;
 154     ret = avio_read(pb, buf + 1, 4);
 155     if (ret < 4)
 156         return AV_NOPTS_VALUE;
 157
 158     return ff_parse_pes_pts(buf);
 159 }
 160
 161 static int find_next_start_code(AVIOContext *pb, int *size_ptr,
 162                                 int32_t *header_state)
 163 {
 164     unsigned int state, v;
 165     int val, n;
 166
 167     state = *header_state;
 168     n     = *size_ptr;
 169     while (n > 0) {
 170         if (avio_feof(pb))
 171             break;
 172         v = avio_r8(pb);
 173         n--;
 174         if (state == 0x000001) {
 175             state = ((state << 8) | v) & 0xffffff;
 176             val   = state;
 177             goto found;
 178         }
 179         state = ((state << 8) | v) & 0xffffff;
 180     }
 181     val = -1;
 182
 183 found:
 184     *header_state = state;
 185     *size_ptr     = n;
 186     return val;
 187 }
 188
 189 /**
 190  * Extract stream types from a program stream map
 191  * According to ISO/IEC 13818-1 ('MPEG-2 Systems') table 2-35
 192  *
 193  * @return number of bytes occupied by PSM in the bitstream
 194  */
 195 static long mpegps_psm_parse(MpegDemuxContext *m, AVIOContext *pb)
 196 {
 197     int psm_length, ps_info_length, es_map_length;
 198
 199     psm_length = avio_rb16(pb);
 200     avio_r8(pb);
 201     avio_r8(pb);
 202     ps_info_length = avio_rb16(pb);
 203
 204     /* skip program_stream_info */
 205     avio_skip(pb, ps_info_length);
 206     /*es_map_length = */avio_rb16(pb);
 207     /* Ignore es_map_length, trust psm_length */
 208     es_map_length = psm_length - ps_info_length - 10;
 209
 210     /* at least one es available? */
 211     while (es_map_length >= 4) {
 212         unsigned char type      = avio_r8(pb);
 213         unsigned char es_id     = avio_r8(pb);
 214         uint16_t es_info_length = avio_rb16(pb);
 215
 216         /* remember mapping from stream id to stream type */
 217         m->psm_es_type[es_id] = type;
 218         /* skip program_stream_info */
 219         avio_skip(pb, es_info_length);
 220         es_map_length -= 4 + es_info_length;
 221     }
 222     avio_rb32(pb); /* crc32 */
 223     return 2 + psm_length;
 224 }
 225
 226 /* read the next PES header. Return its position in ppos
 227  * (if not NULL), and its start code, pts and dts.
 228  */
 229 static int mpegps_read_pes_header(AVFormatContext *s,
 230                                   int64_t *ppos, int *pstart_code,
 231                                   int64_t *ppts, int64_t *pdts)
 232 {
 233     MpegDemuxContext *m = s->priv_data;
 234     int len, size, startcode, c, flags, header_len;
 235     int pes_ext, ext2_len, id_ext, skip;
 236     int64_t pts, dts;
 237     int64_t last_sync = avio_tell(s->pb);
 238
 239 error_redo:
 240     avio_seek(s->pb, last_sync, SEEK_SET);
 241 redo:
 242     /* next start code (should be immediately after) */
 243     m->header_state = 0xff;
 244     size      = MAX_SYNC_SIZE;
 245     startcode = find_next_start_code(s->pb, &size, &m->header_state);
 246     last_sync = avio_tell(s->pb);
 247     if (startcode < 0) {
 248         if (avio_feof(s->pb))
 249             return AVERROR_EOF;
 250         // FIXME we should remember header_state
 251         return FFERROR_REDO;
 252     }
 253
 254     if (startcode == PACK_START_CODE)
 255         goto redo;
 256     if (startcode == SYSTEM_HEADER_START_CODE)
 257         goto redo;
 258     if (startcode == PADDING_STREAM) {
 259         avio_skip(s->pb, avio_rb16(s->pb));
 260         goto redo;
 261     }
 262     if (startcode == PRIVATE_STREAM_2) {
 263         if (!m->sofdec) {
 264             /* Need to detect whether this from a DVD or a 'Sofdec' stream */
 265             int len = avio_rb16(s->pb);
 266             int bytesread = 0;
 267             uint8_t *ps2buf = av_malloc(len);
 268
 269             if (ps2buf) {
 270                 bytesread = avio_read(s->pb, ps2buf, len);
 271
 272                 if (bytesread != len) {
 273                     avio_skip(s->pb, len - bytesread);
 274                 } else {
 275                     uint8_t *p = 0;
 276                     if (len >= 6)
 277                         p = memchr(ps2buf, 'S', len - 5);
 278
 279                     if (p)
 280                         m->sofdec = !memcmp(p+1, "ofdec", 5);
 281
 282                     m->sofdec -= !m->sofdec;
 283
 284                     if (m->sofdec < 0) {
 285                         if (len == 980  && ps2buf[0] == 0) {
 286                             /* PCI structure? */
 287                             uint32_t startpts = AV_RB32(ps2buf + 0x0d);
 288                             uint32_t endpts = AV_RB32(ps2buf + 0x11);
 289                             uint8_t hours = ((ps2buf[0x19] >> 4) * 10) + (ps2buf[0x19] & 0x0f);
 290                             uint8_t mins  = ((ps2buf[0x1a] >> 4) * 10) + (ps2buf[0x1a] & 0x0f);
 291                             uint8_t secs  = ((ps2buf[0x1b] >> 4) * 10) + (ps2buf[0x1b] & 0x0f);
 292
 293                             m->dvd = (hours <= 23 &&
 294                                       mins  <= 59 &&
 295                                       secs  <= 59 &&
 296                                       (ps2buf[0x19] & 0x0f) < 10 &&
 297                                       (ps2buf[0x1a] & 0x0f) < 10 &&
 298                                       (ps2buf[0x1b] & 0x0f) < 10 &&
 299                                       endpts >= startpts);
 300                         } else if (len == 1018 && ps2buf[0] == 1) {
 301                             /* DSI structure? */
 302                             uint8_t hours = ((ps2buf[0x1d] >> 4) * 10) + (ps2buf[0x1d] & 0x0f);
 303                             uint8_t mins  = ((ps2buf[0x1e] >> 4) * 10) + (ps2buf[0x1e] & 0x0f);
 304                             uint8_t secs  = ((ps2buf[0x1f] >> 4) * 10) + (ps2buf[0x1f] & 0x0f);
 305
 306                             m->dvd = (hours <= 23 &&
 307                                       mins  <= 59 &&
 308                                       secs  <= 59 &&
 309                                       (ps2buf[0x1d] & 0x0f) < 10 &&
 310                                       (ps2buf[0x1e] & 0x0f) < 10 &&
 311                                       (ps2buf[0x1f] & 0x0f) < 10);
 312                         }
 313                     }
 314                 }
 315
 316                 av_free(ps2buf);
 317
 318                 /* If this isn't a DVD packet or no memory
 319                  * could be allocated, just ignore it.
 320                  * If we did, move back to the start of the
 321                  * packet (plus 'length' field) */
 322                 if (!m->dvd || avio_skip(s->pb, -(len + 2)) < 0) {
 323                     /* Skip back failed.
 324                      * This packet will be lost but that can't be helped
 325                      * if we can't skip back
 326                      */
 327                     goto redo;
 328                 }
 329             } else {
 330                 /* No memory */
 331                 avio_skip(s->pb, len);
 332                 goto redo;
 333             }
 334         } else if (!m->dvd) {
 335             int len = avio_rb16(s->pb);
 336             avio_skip(s->pb, len);
 337             goto redo;
 338         }
 339     }
 340     if (startcode == PROGRAM_STREAM_MAP) {
 341         mpegps_psm_parse(m, s->pb);
 342         goto redo;
 343     }
 344
 345     /* find matching stream */
 346     if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
 347           (startcode >= 0x1e0 && startcode <= 0x1ef) ||
 348           (startcode == 0x1bd) ||
 349           (startcode == PRIVATE_STREAM_2) ||
 350           (startcode == 0x1fd)))
 351         goto redo;
 352     if (ppos) {
 353         *ppos = avio_tell(s->pb) - 4;
 354     }
 355     len = avio_rb16(s->pb);
 356     pts =
 357     dts = AV_NOPTS_VALUE;
 358     if (startcode != PRIVATE_STREAM_2)
 359     {
 360     /* stuffing */
 361     for (;;) {
 362         if (len < 1)
 363             goto error_redo;
 364         c = avio_r8(s->pb);
 365         len--;
 366         /* XXX: for MPEG-1, should test only bit 7 */
 367         if (c != 0xff)
 368             break;
 369     }
 370     if ((c & 0xc0) == 0x40) {
 371         /* buffer scale & size */
 372         avio_r8(s->pb);
 373         c    = avio_r8(s->pb);
 374         len -= 2;
 375     }
 376     if ((c & 0xe0) == 0x20) {
 377         dts  =
 378         pts  = get_pts(s->pb, c);
 379         len -= 4;
 380         if (c & 0x10) {
 381             dts  = get_pts(s->pb, -1);
 382             len -= 5;
 383         }
 384     } else if ((c & 0xc0) == 0x80) {
 385         /* mpeg 2 PES */
 386         flags      = avio_r8(s->pb);
 387         header_len = avio_r8(s->pb);
 388         len       -= 2;
 389         if (header_len > len)
 390             goto error_redo;
 391         len -= header_len;
 392         if (flags & 0x80) {
 393             dts         = pts = get_pts(s->pb, -1);
 394             header_len -= 5;
 395             if (flags & 0x40) {
 396                 dts         = get_pts(s->pb, -1);
 397                 header_len -= 5;
 398             }
 399         }
 400         if (flags & 0x3f && header_len == 0) {
 401             flags &= 0xC0;
 402             av_log(s, AV_LOG_WARNING, "Further flags set but no bytes left\n");
 403         }
 404         if (flags & 0x01) { /* PES extension */
 405             pes_ext = avio_r8(s->pb);
 406             header_len--;
 407             /* Skip PES private data, program packet sequence counter
 408              * and P-STD buffer */
 409             skip  = (pes_ext >> 4) & 0xb;
 410             skip += skip & 0x9;
 411             if (pes_ext & 0x40 || skip > header_len) {
 412                 av_log(s, AV_LOG_WARNING, "pes_ext %X is invalid\n", pes_ext);
 413                 pes_ext = skip = 0;
 414             }
 415             avio_skip(s->pb, skip);
 416             header_len -= skip;
 417
 418             if (pes_ext & 0x01) { /* PES extension 2 */
 419                 ext2_len = avio_r8(s->pb);
 420                 header_len--;
 421                 if ((ext2_len & 0x7f) > 0) {
 422                     id_ext = avio_r8(s->pb);
 423                     if ((id_ext & 0x80) == 0)
 424                         startcode = ((startcode & 0xff) << 8) | id_ext;
 425                     header_len--;
 426                 }
 427             }
 428         }
 429         if (header_len < 0)
 430             goto error_redo;
 431         avio_skip(s->pb, header_len);
 432     } else if (c != 0xf)
 433         goto redo;
 434     }
 435
 436     if (startcode == PRIVATE_STREAM_1) {
 437         int ret = ffio_ensure_seekback(s->pb, 2);
 438
 439         if (ret < 0)
 440             return ret;
 441
 442         startcode = avio_r8(s->pb);
 443         m->raw_ac3 = 0;
 444         if (startcode == 0x0b) {
 445             if (avio_r8(s->pb) == 0x77) {
 446                 startcode = 0x80;
 447                 m->raw_ac3 = 1;
 448                 avio_skip(s->pb, -2);
 449             } else {
 450                 avio_skip(s->pb, -1);
 451             }
 452         } else {
 453             len--;
 454         }
 455     }
 456     if (len < 0)
 457         goto error_redo;
 458     if (dts != AV_NOPTS_VALUE && ppos) {
 459         int i;
 460         for (i = 0; i < s->nb_streams; i++) {
 461             if (startcode == s->streams[i]->id &&
 462                 (s->pb->seekable & AVIO_SEEKABLE_NORMAL) /* index useless on streams anyway */) {
 463                 ff_reduce_index(s, i);
 464                 av_add_index_entry(s->streams[i], *ppos, dts, 0, 0,
 465                                    AVINDEX_KEYFRAME /* FIXME keyframe? */);
 466             }
 467         }
 468     }
 469
 470     *pstart_code = startcode;
 471     *ppts        = pts;
 472     *pdts        = dts;
 473     return len;
 474 }
 475
 476 static int mpegps_read_packet(AVFormatContext *s,
 477                               AVPacket *pkt)
 478 {
 479     MpegDemuxContext *m = s->priv_data;
 480     AVStream *st;
 481     FFStream *sti;
 482     int len, startcode, i, es_type, ret;
 483     int pcm_dvd = 0;
 484     int request_probe= 0;
 485     enum AVCodecID codec_id = AV_CODEC_ID_NONE;
 486     enum AVMediaType type;
 487     int64_t pts, dts, dummy_pos; // dummy_pos is needed for the index building to work
 488
 489 redo:
 490     len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts);
 491     if (len < 0)
 492         return len;
 493
 494     if (startcode >= 0x80 && startcode <= 0xcf) {
 495         if (len < 4)
 496             goto skip;
 497
 498         if (!m->raw_ac3) {
 499             /* audio: skip header */
 500             avio_skip(s->pb, 3);
 501             len -= 3;
 502             if (startcode >= 0xb0 && startcode <= 0xbf) {
 503                 /* MLP/TrueHD audio has a 4-byte header */
 504                 avio_r8(s->pb);
 505                 len--;
 506             } else if (startcode >= 0xa0 && startcode <= 0xaf) {
 507                 ret = ffio_ensure_seekback(s->pb, 3);
 508                 if (ret < 0)
 509                     return ret;
 510                 pcm_dvd = (avio_rb24(s->pb) & 0xFF) == 0x80;
 511                 avio_skip(s->pb, -3);
 512             }
 513         }
 514     }
 515
 516     /* now find stream */
 517     for (i = 0; i < s->nb_streams; i++) {
 518         st = s->streams[i];
 519         if (st->id == startcode)
 520             goto found;
 521     }
 522
 523     es_type = m->psm_es_type[startcode & 0xff];
 524     if (es_type == STREAM_TYPE_VIDEO_MPEG1) {
 525         codec_id = AV_CODEC_ID_MPEG2VIDEO;
 526         type     = AVMEDIA_TYPE_VIDEO;
 527     } else if (es_type == STREAM_TYPE_VIDEO_MPEG2) {
 528         codec_id = AV_CODEC_ID_MPEG2VIDEO;
 529         type     = AVMEDIA_TYPE_VIDEO;
 530     } else if (es_type == STREAM_TYPE_AUDIO_MPEG1 ||
 531                es_type == STREAM_TYPE_AUDIO_MPEG2) {
 532         codec_id = AV_CODEC_ID_MP3;
 533         type     = AVMEDIA_TYPE_AUDIO;
 534     } else if (es_type == STREAM_TYPE_AUDIO_AAC) {
 535         codec_id = AV_CODEC_ID_AAC;
 536         type     = AVMEDIA_TYPE_AUDIO;
 537     } else if (es_type == STREAM_TYPE_VIDEO_MPEG4) {
 538         codec_id = AV_CODEC_ID_MPEG4;
 539         type     = AVMEDIA_TYPE_VIDEO;
 540     } else if (es_type == STREAM_TYPE_VIDEO_H264) {
 541         codec_id = AV_CODEC_ID_H264;
 542         type     = AVMEDIA_TYPE_VIDEO;
 543     } else if (es_type == STREAM_TYPE_VIDEO_HEVC) {
 544         codec_id = AV_CODEC_ID_HEVC;
 545         type     = AVMEDIA_TYPE_VIDEO;
 546     } else if (es_type == STREAM_TYPE_AUDIO_AC3) {
 547         codec_id = AV_CODEC_ID_AC3;
 548         type     = AVMEDIA_TYPE_AUDIO;
 549     } else if (m->imkh_cctv && es_type == 0x91) {
 550         codec_id = AV_CODEC_ID_PCM_MULAW;
 551         type     = AVMEDIA_TYPE_AUDIO;
 552     } else if (startcode >= 0x1e0 && startcode <= 0x1ef) {
 553         static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 };
 554         unsigned char buf[8];
 555
 556         avio_read(s->pb, buf, 8);
 557         avio_seek(s->pb, -8, SEEK_CUR);
 558         if (!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1))
 559             codec_id = AV_CODEC_ID_CAVS;
 560         else
 561             request_probe= 1;
 562         type = AVMEDIA_TYPE_VIDEO;
 563     } else if (startcode == PRIVATE_STREAM_2) {
 564         type = AVMEDIA_TYPE_DATA;
 565         codec_id = AV_CODEC_ID_DVD_NAV;
 566     } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
 567         type     = AVMEDIA_TYPE_AUDIO;
 568         if (m->sofdec > 0) {
 569             codec_id = AV_CODEC_ID_ADPCM_ADX;
 570             // Auto-detect AC-3
 571             request_probe = 50;
 572         } else if (m->imkh_cctv && startcode == 0x1c0 && len > 80) {
 573             codec_id = AV_CODEC_ID_PCM_ALAW;
 574             request_probe = 50;
 575         } else {
 576             codec_id = AV_CODEC_ID_MP2;
 577             if (m->imkh_cctv)
 578                 request_probe = 25;
 579         }
 580     } else if (startcode >= 0x80 && startcode <= 0x87) {
 581         type     = AVMEDIA_TYPE_AUDIO;
 582         codec_id = AV_CODEC_ID_AC3;
 583     } else if ((startcode >= 0x88 && startcode <= 0x8f) ||
 584                (startcode >= 0x98 && startcode <= 0x9f)) {
 585         /* 0x90 - 0x97 is reserved for SDDS in DVD specs */
 586         type     = AVMEDIA_TYPE_AUDIO;
 587         codec_id = AV_CODEC_ID_DTS;
 588     } else if (startcode >= 0xa0 && startcode <= 0xaf) {
 589         type     = AVMEDIA_TYPE_AUDIO;
 590         if (!pcm_dvd) {
 591             codec_id = AV_CODEC_ID_MLP;
 592         } else {
 593             codec_id = AV_CODEC_ID_PCM_DVD;
 594         }
 595     } else if (startcode >= 0xb0 && startcode <= 0xbf) {
 596         type     = AVMEDIA_TYPE_AUDIO;
 597         codec_id = AV_CODEC_ID_TRUEHD;
 598     } else if (startcode >= 0xc0 && startcode <= 0xcf) {
 599         /* Used for both AC-3 and E-AC-3 in EVOB files */
 600         type     = AVMEDIA_TYPE_AUDIO;
 601         codec_id = AV_CODEC_ID_AC3;
 602     } else if (startcode >= 0x20 && startcode <= 0x3f) {
 603         type     = AVMEDIA_TYPE_SUBTITLE;
 604         codec_id = AV_CODEC_ID_DVD_SUBTITLE;
 605     } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) {
 606         type     = AVMEDIA_TYPE_VIDEO;
 607         codec_id = AV_CODEC_ID_VC1;
 608     } else {
 609 skip:
 610         /* skip packet */
 611         avio_skip(s->pb, len);
 612         goto redo;
 613     }
 614     /* no stream found: add a new stream */
 615     st = avformat_new_stream(s, NULL);
 616     if (!st)
 617         goto skip;
 618     sti = ffstream(st);
 619     st->id                = startcode;
 620     st->codecpar->codec_type = type;
 621     st->codecpar->codec_id   = codec_id;
 622     if (   st->codecpar->codec_id == AV_CODEC_ID_PCM_MULAW
 623         || st->codecpar->codec_id == AV_CODEC_ID_PCM_ALAW) {
 624         st->codecpar->channels = 1;
 625         st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
 626         st->codecpar->sample_rate = 8000;
 627     }
 628     sti->request_probe = request_probe;
 629     sti->need_parsing  = AVSTREAM_PARSE_FULL;
 630
 631 found:
 632     if (st->discard >= AVDISCARD_ALL)
 633         goto skip;
 634     if (startcode >= 0xa0 && startcode <= 0xaf) {
 635       if (st->codecpar->codec_id == AV_CODEC_ID_MLP) {
 636             if (len < 6)
 637                 goto skip;
 638             avio_skip(s->pb, 6);
 639             len -=6;
 640       }
 641     }
 642     ret = av_get_packet(s->pb, pkt, len);
 643
 644     pkt->pts          = pts;
 645     pkt->dts          = dts;
 646     pkt->pos          = dummy_pos;
 647     pkt->stream_index = st->index;
 648
 649     if (s->debug & FF_FDEBUG_TS)
 650         av_log(s, AV_LOG_DEBUG, "%d: pts=%0.3f dts=%0.3f size=%d\n",
 651             pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0,
 652             pkt->size);
 653
 654     return (ret < 0) ? ret : 0;
 655 }
 656
 657 static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,
 658                                int64_t *ppos, int64_t pos_limit)
 659 {
 660     int len, startcode;
 661     int64_t pos, pts, dts;
 662
 663     pos = *ppos;
 664     if (avio_seek(s->pb, pos, SEEK_SET) < 0)
 665         return AV_NOPTS_VALUE;
 666
 667     for (;;) {
 668         len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts);
 669         if (len < 0) {
 670             if (s->debug & FF_FDEBUG_TS)
 671                 av_log(s, AV_LOG_DEBUG, "none (ret=%d)\n", len);
 672             return AV_NOPTS_VALUE;
 673         }
 674         if (startcode == s->streams[stream_index]->id &&
 675             dts != AV_NOPTS_VALUE) {
 676             break;
 677         }
 678         avio_skip(s->pb, len);
 679     }
 680     if (s->debug & FF_FDEBUG_TS)
 681         av_log(s, AV_LOG_DEBUG, "pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n",
 682             pos, dts, dts / 90000.0);
 683     *ppos = pos;
 684     return dts;
 685 }
 686
 687 const AVInputFormat ff_mpegps_demuxer = {
 688     .name           = "mpeg",
 689     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-PS (MPEG-2 Program Stream)"),
 690     .priv_data_size = sizeof(MpegDemuxContext),
 691     .read_probe     = mpegps_probe,
 692     .read_header    = mpegps_read_header,
 693     .read_packet    = mpegps_read_packet,
 694     .read_timestamp = mpegps_read_dts,
 695     .flags          = AVFMT_SHOW_IDS | AVFMT_TS_DISCONT,
 696 };
 697
 698 #if CONFIG_VOBSUB_DEMUXER
 699
 700 #include "subtitles.h"
 701 #include "libavutil/avassert.h"
 702 #include "libavutil/bprint.h"
 703 #include "libavutil/opt.h"
 704
 705 #define REF_STRING "# VobSub index file,"
 706 #define MAX_LINE_SIZE 2048
 707
 708 typedef struct VobSubDemuxContext {
 709     const AVClass *class;
 710     AVFormatContext *sub_ctx;
 711     FFDemuxSubtitlesQueue q[32];
 712     char *sub_name;
 713 } VobSubDemuxContext;
 714
 715 static int vobsub_probe(const AVProbeData *p)
 716 {
 717     if (!strncmp(p->buf, REF_STRING, sizeof(REF_STRING) - 1))
 718         return AVPROBE_SCORE_MAX;
 719     return 0;
 720 }
 721
 722 static int vobsub_read_close(AVFormatContext *s)
 723 {
 724     VobSubDemuxContext *vobsub = s->priv_data;
 725     int i;
 726
 727     for (i = 0; i < s->nb_streams; i++)
 728         ff_subtitles_queue_clean(&vobsub->q[i]);
 729     avformat_close_input(&vobsub->sub_ctx);
 730     return 0;
 731 }
 732
 733 static int vobsub_read_header(AVFormatContext *s)
 734 {
 735     int i, ret = 0, header_parsed = 0, langidx = 0;
 736     VobSubDemuxContext *vobsub = s->priv_data;
 737     const AVInputFormat *iformat;
 738     size_t fname_len;
 739     AVBPrint header;
 740     int64_t delay = 0;
 741     AVStream *st = NULL;
 742     int stream_id = -1;
 743     char id[64] = {0};
 744     char alt[MAX_LINE_SIZE] = {0};
 745
 746     if (!vobsub->sub_name) {
 747         char *ext;
 748         vobsub->sub_name = av_strdup(s->url);
 749         if (!vobsub->sub_name) {
 750             return AVERROR(ENOMEM);
 751         }
 752
 753         fname_len = strlen(vobsub->sub_name);
 754         ext = vobsub->sub_name - 3 + fname_len;
 755         if (fname_len < 4 || *(ext - 1) != '.') {
 756             av_log(s, AV_LOG_ERROR, "The input index filename is too short "
 757                    "to guess the associated .SUB file\n");
 758             return AVERROR_INVALIDDATA;
 759         }
 760         memcpy(ext, !strncmp(ext, "IDX", 3) ? "SUB" : "sub", 3);
 761         av_log(s, AV_LOG_VERBOSE, "IDX/SUB: %s -> %s\n", s->url, vobsub->sub_name);
 762     }
 763
 764     if (!(iformat = av_find_input_format("mpeg"))) {
 765         return AVERROR_DEMUXER_NOT_FOUND;
 766     }
 767
 768     vobsub->sub_ctx = avformat_alloc_context();
 769     if (!vobsub->sub_ctx) {
 770         return AVERROR(ENOMEM);
 771     }
 772
 773     if ((ret = ff_copy_whiteblacklists(vobsub->sub_ctx, s)) < 0)
 774         return ret;
 775
 776     ret = avformat_open_input(&vobsub->sub_ctx, vobsub->sub_name, iformat, NULL);
 777     if (ret < 0) {
 778         av_log(s, AV_LOG_ERROR, "Unable to open %s as MPEG subtitles\n", vobsub->sub_name);
 779         return ret;
 780     }
 781
 782     av_bprint_init(&header, 0, INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE);
 783
 784     while (!avio_feof(s->pb)) {
 785         char line[MAX_LINE_SIZE];
 786         int len = ff_get_line(s->pb, line, sizeof(line));
 787
 788         if (!len)
 789             break;
 790
 791         line[strcspn(line, "\r\n")] = 0;
 792
 793         if (!strncmp(line, "id:", 3)) {
 794             if (sscanf(line, "id: %63[^,], index: %u", id, &stream_id) != 2) {
 795                 av_log(s, AV_LOG_WARNING, "Unable to parse index line '%s', "
 796                        "assuming 'id: und, index: 0'\n", line);
 797                 strcpy(id, "und");
 798                 stream_id = 0;
 799             }
 800
 801             if (stream_id >= FF_ARRAY_ELEMS(vobsub->q)) {
 802                 av_log(s, AV_LOG_ERROR, "Maximum number of subtitles streams reached\n");
 803                 ret = AVERROR(EINVAL);
 804                 goto end;
 805             }
 806
 807             header_parsed = 1;
 808             alt[0] = '\0';
 809             /* We do not create the stream immediately to avoid adding empty
 810              * streams. See the following timestamp entry. */
 811
 812             av_log(s, AV_LOG_DEBUG, "IDX stream[%d] id=%s\n", stream_id, id);
 813
 814         } else if (!strncmp(line, "timestamp:", 10)) {
 815             AVPacket *sub;
 816             int hh, mm, ss, ms;
 817             int64_t pos, timestamp;
 818             const char *p = line + 10;
 819
 820             if (stream_id == -1) {
 821                 av_log(s, AV_LOG_ERROR, "Timestamp declared before any stream\n");
 822                 ret = AVERROR_INVALIDDATA;
 823                 goto end;
 824             }
 825
 826             if (!st || st->id != stream_id) {
 827                 st = avformat_new_stream(s, NULL);
 828                 if (!st) {
 829                     ret = AVERROR(ENOMEM);
 830                     goto end;
 831                 }
 832                 st->id = stream_id;
 833                 st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
 834                 st->codecpar->codec_id   = AV_CODEC_ID_DVD_SUBTITLE;
 835                 avpriv_set_pts_info(st, 64, 1, 1000);
 836                 av_dict_set(&st->metadata, "language", id, 0);
 837                 if (alt[0])
 838                     av_dict_set(&st->metadata, "title", alt, 0);
 839             }
 840
 841             if (sscanf(p, "%02d:%02d:%02d:%03d, filepos: %"SCNx64,
 842                        &hh, &mm, &ss, &ms, &pos) != 5) {
 843                 av_log(s, AV_LOG_ERROR, "Unable to parse timestamp line '%s', "
 844                        "abort parsing\n", line);
 845                 ret = AVERROR_INVALIDDATA;
 846                 goto end;
 847             }
 848             timestamp = (hh*3600LL + mm*60LL + ss) * 1000LL + ms + delay;
 849             timestamp = av_rescale_q(timestamp, av_make_q(1, 1000), st->time_base);
 850
 851             sub = ff_subtitles_queue_insert(&vobsub->q[s->nb_streams - 1], "", 0, 0);
 852             if (!sub) {
 853                 ret = AVERROR(ENOMEM);
 854                 goto end;
 855             }
 856             sub->pos = pos;
 857             sub->pts = timestamp;
 858             sub->stream_index = s->nb_streams - 1;
 859
 860         } else if (!strncmp(line, "alt:", 4)) {
 861             const char *p = line + 4;
 862
 863             while (*p == ' ')
 864                 p++;
 865             av_log(s, AV_LOG_DEBUG, "IDX stream[%d] name=%s\n", stream_id, p);
 866             av_strlcpy(alt, p, sizeof(alt));
 867             header_parsed = 1;
 868
 869         } else if (!strncmp(line, "delay:", 6)) {
 870             int sign = 1, hh = 0, mm = 0, ss = 0, ms = 0;
 871             const char *p = line + 6;
 872
 873             while (*p == ' ')
 874                 p++;
 875             if (*p == '-' || *p == '+') {
 876                 sign = *p == '-' ? -1 : 1;
 877                 p++;
 878             }
 879             sscanf(p, "%d:%d:%d:%d", &hh, &mm, &ss, &ms);
 880             delay = ((hh*3600LL + mm*60LL + ss) * 1000LL + ms) * sign;
 881
 882         } else if (!strncmp(line, "langidx:", 8)) {
 883             const char *p = line + 8;
 884
 885             if (sscanf(p, "%d", &langidx) != 1)
 886                 av_log(s, AV_LOG_ERROR, "Invalid langidx specified\n");
 887
 888         } else if (!header_parsed) {
 889             if (line[0] && line[0] != '#')
 890                 av_bprintf(&header, "%s\n", line);
 891         }
 892     }
 893
 894     if (langidx < s->nb_streams)
 895         s->streams[langidx]->disposition |= AV_DISPOSITION_DEFAULT;
 896
 897     for (i = 0; i < s->nb_streams; i++) {
 898         vobsub->q[i].sort = SUB_SORT_POS_TS;
 899         vobsub->q[i].keep_duplicates = 1;
 900         ff_subtitles_queue_finalize(s, &vobsub->q[i]);
 901     }
 902
 903     if (!av_bprint_is_complete(&header)) {
 904         ret = AVERROR(ENOMEM);
 905         goto end;
 906     }
 907     for (i = 0; i < s->nb_streams; i++) {
 908         AVCodecParameters *par = s->streams[i]->codecpar;
 909         ret = ff_alloc_extradata(par, header.len);
 910         if (ret < 0) {
 911             goto end;
 912         }
 913         memcpy(par->extradata, header.str, header.len);
 914     }
 915 end:
 916     av_bprint_finalize(&header, NULL);
 917     return ret;
 918 }
 919
 920 static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)
 921 {
 922     VobSubDemuxContext *vobsub = s->priv_data;
 923     FFDemuxSubtitlesQueue *q;
 924     AVIOContext *pb = vobsub->sub_ctx->pb;
 925     int ret, psize, total_read = 0, i;
 926
 927     int64_t min_ts = INT64_MAX;
 928     int sid = 0;
 929     for (i = 0; i < s->nb_streams; i++) {
 930         FFDemuxSubtitlesQueue *tmpq = &vobsub->q[i];
 931         int64_t ts;
 932         av_assert0(tmpq->nb_subs);
 933
 934         if (tmpq->current_sub_idx >= tmpq->nb_subs)
 935             continue;
 936
 937         ts = tmpq->subs[tmpq->current_sub_idx]->pts;
 938         if (ts < min_ts) {
 939             min_ts = ts;
 940             sid = i;
 941         }
 942     }
 943     q = &vobsub->q[sid];
 944     /* The returned packet will have size zero,
 945      * so that it can be directly used with av_grow_packet. */
 946     ret = ff_subtitles_queue_read_packet(q, pkt);
 947     if (ret < 0)
 948         return ret;
 949
 950     /* compute maximum packet size using the next packet position. This is
 951      * useful when the len in the header is non-sense */
 952     if (q->current_sub_idx < q->nb_subs) {
 953         psize = q->subs[q->current_sub_idx]->pos - pkt->pos;
 954     } else {
 955         int64_t fsize = avio_size(pb);
 956         psize = fsize < 0 ? 0xffff : fsize - pkt->pos;
 957     }
 958
 959     avio_seek(pb, pkt->pos, SEEK_SET);
 960
 961     do {
 962         int n, to_read, startcode;
 963         int64_t pts, dts;
 964         int64_t old_pos = avio_tell(pb), new_pos;
 965         int pkt_size;
 966
 967         ret = mpegps_read_pes_header(vobsub->sub_ctx, NULL, &startcode, &pts, &dts);
 968         if (ret < 0) {
 969             if (pkt->size) // raise packet even if incomplete
 970                 break;
 971             return ret;
 972         }
 973         to_read = ret & 0xffff;
 974         new_pos = avio_tell(pb);
 975         pkt_size = ret + (new_pos - old_pos);
 976
 977         /* this prevents reads above the current packet */
 978         if (total_read + pkt_size > psize)
 979             break;
 980         total_read += pkt_size;
 981
 982         /* the current chunk doesn't match the stream index (unlikely) */
 983         if ((startcode & 0x1f) != s->streams[pkt->stream_index]->id)
 984             break;
 985
 986         ret = av_grow_packet(pkt, to_read);
 987         if (ret < 0)
 988             return ret;
 989
 990         n = avio_read(pb, pkt->data + (pkt->size - to_read), to_read);
 991         if (n < to_read)
 992             pkt->size -= to_read - n;
 993     } while (total_read < psize);
 994
 995     return 0;
 996 }
 997
 998 static int vobsub_read_seek(AVFormatContext *s, int stream_index,
 999                             int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
1000 {
1001     VobSubDemuxContext *vobsub = s->priv_data;
1002
1003     /* Rescale requested timestamps based on the first stream (timebase is the
1004      * same for all subtitles stream within a .idx/.sub). Rescaling is done just
1005      * like in avformat_seek_file(). */
1006     if (stream_index == -1 && s->nb_streams != 1) {
1007         int i, ret = 0;
1008         AVRational time_base = s->streams[0]->time_base;
1009         ts = av_rescale_q(ts, AV_TIME_BASE_Q, time_base);
1010         min_ts = av_rescale_rnd(min_ts, time_base.den,
1011                                 time_base.num * (int64_t)AV_TIME_BASE,
1012                                 AV_ROUND_UP   | AV_ROUND_PASS_MINMAX);
1013         max_ts = av_rescale_rnd(max_ts, time_base.den,
1014                                 time_base.num * (int64_t)AV_TIME_BASE,
1015                                 AV_ROUND_DOWN | AV_ROUND_PASS_MINMAX);
1016         for (i = 0; i < s->nb_streams; i++) {
1017             int r = ff_subtitles_queue_seek(&vobsub->q[i], s, stream_index,
1018                                             min_ts, ts, max_ts, flags);
1019             if (r < 0)
1020                 ret = r;
1021         }
1022         return ret;
1023     }
1024
1025     if (stream_index == -1) // only 1 stream
1026         stream_index = 0;
1027     return ff_subtitles_queue_seek(&vobsub->q[stream_index], s, stream_index,
1028                                    min_ts, ts, max_ts, flags);
1029 }
1030
1031 static const AVOption options[] = {
1032     { "sub_name", "URI for .sub file", offsetof(VobSubDemuxContext, sub_name), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, AV_OPT_FLAG_DECODING_PARAM },
1033     { NULL }
1034 };
1035
1036 static const AVClass vobsub_demuxer_class = {
1037     .class_name = "vobsub",
1038     .item_name  = av_default_item_name,
1039     .option     = options,
1040     .version    = LIBAVUTIL_VERSION_INT,
1041 };
1042
1043 const AVInputFormat ff_vobsub_demuxer = {
1044     .name           = "vobsub",
1045     .long_name      = NULL_IF_CONFIG_SMALL("VobSub subtitle format"),
1046     .priv_data_size = sizeof(VobSubDemuxContext),
1047     .flags_internal = FF_FMT_INIT_CLEANUP,
1048     .read_probe     = vobsub_probe,
1049     .read_header    = vobsub_read_header,
1050     .read_packet    = vobsub_read_packet,
1051     .read_seek2     = vobsub_read_seek,
1052     .read_close     = vobsub_read_close,
1053     .flags          = AVFMT_SHOW_IDS,
1054     .extensions     = "idx",
1055     .priv_class     = &vobsub_demuxer_class,
1056 };
1057 #endif