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 "config_components.h"
  23
  24 #include "libavutil/channel_layout.h"
  25 #include "libavutil/mem.h"
  26 #include "avformat.h"
  27 #include "avio_internal.h"
  28 #include "demux.h"
  29 #include "internal.h"
  30 #include "mpeg.h"
  31
  32 /*********************************************/
  33 /* demux code */
  34
  35 #define MAX_SYNC_SIZE 100000
  36
  37 static int check_pes(const uint8_t *p, const uint8_t *end)
  38 {
  39     int pes1;
  40     int pes2 = (p[3] & 0xC0) == 0x80 &&
  41                (p[4] & 0xC0) != 0x40 &&
  42                ((p[4] & 0xC0) == 0x00 ||
  43                 (p[4] & 0xC0) >> 2 == (p[6] & 0xF0));
  44
  45     for (p += 3; p < end && *p == 0xFF; p++) ;
  46     if ((*p & 0xC0) == 0x40)
  47         p += 2;
  48
  49     if ((*p & 0xF0) == 0x20)
  50         pes1 = p[0] & p[2] & p[4] & 1;
  51     else if ((*p & 0xF0) == 0x30)
  52         pes1 = p[0] & p[2] & p[4] & p[5] & p[7] & p[9] & 1;
  53     else
  54         pes1 = *p == 0x0F;
  55
  56     return pes1 || pes2;
  57 }
  58
  59 static int check_pack_header(const uint8_t *buf)
  60 {
  61     return (buf[1] & 0xC0) == 0x40 || (buf[1] & 0xF0) == 0x20;
  62 }
  63
  64 static int mpegps_probe(const AVProbeData *p)
  65 {
  66     uint32_t code = -1;
  67     int i;
  68     int sys = 0, pspack = 0, priv1 = 0, vid = 0;
  69     int audio = 0, invalid = 0, score = 0;
  70     int endpes = 0;
  71
  72     for (i = 0; i < p->buf_size; i++) {
  73         code = (code << 8) + p->buf[i];
  74         if ((code & 0xffffff00) == 0x100) {
  75             int len  = p->buf[i + 1] << 8 | p->buf[i + 2];
  76             int pes  = endpes <= i && check_pes(p->buf + i, p->buf + p->buf_size);
  77             int pack = check_pack_header(p->buf + i);
  78
  79             if (len > INT_MAX - i)
  80                 break;
  81
  82             if (code == SYSTEM_HEADER_START_CODE)
  83                 sys++;
  84             else if (code == PACK_START_CODE && pack)
  85                 pspack++;
  86             else if ((code & 0xf0) == VIDEO_ID && pes) {
  87                 endpes = i + len;
  88                 vid++;
  89             }
  90             // skip pes payload to avoid start code emulation for private
  91             // and audio streams
  92             else if ((code & 0xe0) == AUDIO_ID &&  pes) {audio++; i+=len;}
  93             else if (code == PRIVATE_STREAM_1  &&  pes) {priv1++; i+=len;}
  94             else if (code == 0x1fd             &&  pes) vid++; //VC1
  95
  96             else if ((code & 0xf0) == VIDEO_ID && !pes) invalid++;
  97             else if ((code & 0xe0) == AUDIO_ID && !pes) invalid++;
  98             else if (code == PRIVATE_STREAM_1  && !pes) invalid++;
  99         }
 100     }
 101
 102     if (vid + audio > invalid + 1) /* invalid VDR files nd short PES streams */
 103         score = AVPROBE_SCORE_EXTENSION / 2;
 104
 105 //     av_log(NULL, AV_LOG_ERROR, "vid:%d aud:%d sys:%d pspack:%d invalid:%d size:%d \n",
 106 //            vid, audio, sys, pspack, invalid, p->buf_size);
 107
 108     if (sys > invalid && sys * 9 <= pspack * 10)
 109         return (audio > 12 || vid > 3 || pspack > 2) ? AVPROBE_SCORE_EXTENSION + 2
 110                                                      : AVPROBE_SCORE_EXTENSION / 2 + (audio + vid + pspack > 1); // 1 more than mp3
 111     if (pspack > invalid && (priv1 + vid + audio) * 10 >= pspack * 9)
 112         return pspack > 2 ? AVPROBE_SCORE_EXTENSION + 2
 113                           : AVPROBE_SCORE_EXTENSION / 2; // 1 more than .mpg
 114     if ((!!vid ^ !!audio) && (audio > 4 || vid > 1) && !sys &&
 115         !pspack && p->buf_size > 2048 && vid + audio > invalid) /* PES stream */
 116         return (audio > 12 || vid > 6 + 2 * invalid) ? AVPROBE_SCORE_EXTENSION + 2
 117                                                      : AVPROBE_SCORE_EXTENSION / 2;
 118
 119     // 02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1
 120     // mp3_misidentified_2.mp3 has sys:0 priv1:0 pspack:0 vid:0 audio:6
 121     // Have\ Yourself\ a\ Merry\ Little\ Christmas.mp3 0 0 0 5 0 1 len:21618
 122     return score;
 123 }
 124
 125 typedef struct MpegDemuxContext {
 126     int32_t header_state;
 127     unsigned char psm_es_type[256];
 128     int sofdec;
 129     int dvd;
 130     int imkh_cctv;
 131     int raw_ac3;
 132 } MpegDemuxContext;
 133
 134 static int mpegps_read_header(AVFormatContext *s)
 135 {
 136     MpegDemuxContext *m = s->priv_data;
 137     char buffer[7] = { 0 };
 138     int64_t last_pos = avio_tell(s->pb);
 139
 140     m->header_state = 0xff;
 141     s->ctx_flags   |= AVFMTCTX_NOHEADER;
 142
 143     avio_get_str(s->pb, 6, buffer, sizeof(buffer));
 144     if (!memcmp("IMKH", buffer, 4)) {
 145         m->imkh_cctv = 1;
 146     } else if (!memcmp("Sofdec", buffer, 6)) {
 147         m->sofdec = 1;
 148     } else
 149        avio_seek(s->pb, last_pos, SEEK_SET);
 150
 151     /* no need to do more */
 152     return 0;
 153 }
 154
 155 static int64_t get_pts(AVIOContext *pb, int c)
 156 {
 157     uint8_t buf[5];
 158     int ret;
 159
 160     buf[0] = c < 0 ? avio_r8(pb) : c;
 161     ret = avio_read(pb, buf + 1, 4);
 162     if (ret < 4)
 163         return AV_NOPTS_VALUE;
 164
 165     return ff_parse_pes_pts(buf);
 166 }
 167
 168 static int find_next_start_code(AVIOContext *pb, int *size_ptr,
 169                                 int32_t *header_state)
 170 {
 171     unsigned int state, v;
 172     int val, n;
 173
 174     state = *header_state;
 175     n     = *size_ptr;
 176     while (n > 0) {
 177         if (avio_feof(pb))
 178             break;
 179         v = avio_r8(pb);
 180         n--;
 181         if (state == 0x000001) {
 182             state = ((state << 8) | v) & 0xffffff;
 183             val   = state;
 184             goto found;
 185         }
 186         state = ((state << 8) | v) & 0xffffff;
 187     }
 188     val = -1;
 189
 190 found:
 191     *header_state = state;
 192     *size_ptr     = n;
 193     return val;
 194 }
 195
 196 /**
 197  * Extract stream types from a program stream map
 198  * According to ISO/IEC 13818-1 ('MPEG-2 Systems') table 2-35
 199  *
 200  * @return number of bytes occupied by PSM in the bitstream
 201  */
 202 static long mpegps_psm_parse(MpegDemuxContext *m, AVIOContext *pb)
 203 {
 204     int psm_length, ps_info_length, es_map_length;
 205
 206     psm_length = avio_rb16(pb);
 207     avio_r8(pb);
 208     avio_r8(pb);
 209     ps_info_length = avio_rb16(pb);
 210
 211     /* skip program_stream_info */
 212     avio_skip(pb, ps_info_length);
 213     /*es_map_length = */avio_rb16(pb);
 214     /* Ignore es_map_length, trust psm_length */
 215     es_map_length = psm_length - ps_info_length - 10;
 216
 217     /* at least one es available? */
 218     while (es_map_length >= 4) {
 219         unsigned char type      = avio_r8(pb);
 220         unsigned char es_id     = avio_r8(pb);
 221         uint16_t es_info_length = avio_rb16(pb);
 222
 223         /* remember mapping from stream id to stream type */
 224         m->psm_es_type[es_id] = type;
 225         /* skip program_stream_info */
 226         avio_skip(pb, es_info_length);
 227         es_map_length -= 4 + es_info_length;
 228     }
 229     avio_rb32(pb); /* crc32 */
 230     return 2 + psm_length;
 231 }
 232
 233 /* read the next PES header. Return its position in ppos
 234  * (if not NULL), and its start code, pts and dts.
 235  */
 236 static int mpegps_read_pes_header(AVFormatContext *s,
 237                                   int64_t *ppos, int *pstart_code,
 238                                   int64_t *ppts, int64_t *pdts)
 239 {
 240     MpegDemuxContext *m = s->priv_data;
 241     int len, size, startcode, c, flags, header_len;
 242     int pes_ext, ext2_len, id_ext, skip;
 243     int64_t pts, dts;
 244     int64_t last_sync = avio_tell(s->pb);
 245
 246 error_redo:
 247     avio_seek(s->pb, last_sync, SEEK_SET);
 248 redo:
 249     /* next start code (should be immediately after) */
 250     m->header_state = 0xff;
 251     size      = MAX_SYNC_SIZE;
 252     startcode = find_next_start_code(s->pb, &size, &m->header_state);
 253     last_sync = avio_tell(s->pb);
 254     if (startcode < 0) {
 255         if (avio_feof(s->pb))
 256             return AVERROR_EOF;
 257         // FIXME we should remember header_state
 258         return FFERROR_REDO;
 259     }
 260
 261     if (startcode == PACK_START_CODE)
 262         goto redo;
 263     if (startcode == SYSTEM_HEADER_START_CODE)
 264         goto redo;
 265     if (startcode == PADDING_STREAM) {
 266         avio_skip(s->pb, avio_rb16(s->pb));
 267         goto redo;
 268     }
 269     if (startcode == PRIVATE_STREAM_2) {
 270         if (!m->sofdec) {
 271             /* Need to detect whether this from a DVD or a 'Sofdec' stream */
 272             int len = avio_rb16(s->pb);
 273             int bytesread = 0;
 274             uint8_t *ps2buf = av_malloc(len);
 275
 276             if (ps2buf) {
 277                 bytesread = avio_read(s->pb, ps2buf, len);
 278
 279                 if (bytesread != len) {
 280                     avio_skip(s->pb, len - bytesread);
 281                 } else {
 282                     uint8_t *p = 0;
 283                     if (len >= 6)
 284                         p = memchr(ps2buf, 'S', len - 5);
 285
 286                     if (p)
 287                         m->sofdec = !memcmp(p+1, "ofdec", 5);
 288
 289                     m->sofdec -= !m->sofdec;
 290
 291                     if (m->sofdec < 0) {
 292                         if (len == 980  && ps2buf[0] == 0) {
 293                             /* PCI structure? */
 294                             uint32_t startpts = AV_RB32(ps2buf + 0x0d);
 295                             uint32_t endpts = AV_RB32(ps2buf + 0x11);
 296                             uint8_t hours = ((ps2buf[0x19] >> 4) * 10) + (ps2buf[0x19] & 0x0f);
 297                             uint8_t mins  = ((ps2buf[0x1a] >> 4) * 10) + (ps2buf[0x1a] & 0x0f);
 298                             uint8_t secs  = ((ps2buf[0x1b] >> 4) * 10) + (ps2buf[0x1b] & 0x0f);
 299
 300                             m->dvd = (hours <= 23 &&
 301                                       mins  <= 59 &&
 302                                       secs  <= 59 &&
 303                                       (ps2buf[0x19] & 0x0f) < 10 &&
 304                                       (ps2buf[0x1a] & 0x0f) < 10 &&
 305                                       (ps2buf[0x1b] & 0x0f) < 10 &&
 306                                       endpts >= startpts);
 307                         } else if (len == 1018 && ps2buf[0] == 1) {
 308                             /* DSI structure? */
 309                             uint8_t hours = ((ps2buf[0x1d] >> 4) * 10) + (ps2buf[0x1d] & 0x0f);
 310                             uint8_t mins  = ((ps2buf[0x1e] >> 4) * 10) + (ps2buf[0x1e] & 0x0f);
 311                             uint8_t secs  = ((ps2buf[0x1f] >> 4) * 10) + (ps2buf[0x1f] & 0x0f);
 312
 313                             m->dvd = (hours <= 23 &&
 314                                       mins  <= 59 &&
 315                                       secs  <= 59 &&
 316                                       (ps2buf[0x1d] & 0x0f) < 10 &&
 317                                       (ps2buf[0x1e] & 0x0f) < 10 &&
 318                                       (ps2buf[0x1f] & 0x0f) < 10);
 319                         }
 320                     }
 321                 }
 322
 323                 av_free(ps2buf);
 324
 325                 /* If this isn't a DVD packet or no memory
 326                  * could be allocated, just ignore it.
 327                  * If we did, move back to the start of the
 328                  * packet (plus 'length' field) */
 329                 if (!m->dvd || avio_skip(s->pb, -(len + 2)) < 0) {
 330                     /* Skip back failed.
 331                      * This packet will be lost but that can't be helped
 332                      * if we can't skip back
 333                      */
 334                     goto redo;
 335                 }
 336             } else {
 337                 /* No memory */
 338                 avio_skip(s->pb, len);
 339                 goto redo;
 340             }
 341         } else if (!m->dvd) {
 342             int len = avio_rb16(s->pb);
 343             avio_skip(s->pb, len);
 344             goto redo;
 345         }
 346     }
 347     if (startcode == PROGRAM_STREAM_MAP) {
 348         mpegps_psm_parse(m, s->pb);
 349         goto redo;
 350     }
 351
 352     /* find matching stream */
 353     if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
 354           (startcode >= 0x1e0 && startcode <= 0x1ef) ||
 355           (startcode == 0x1bd) ||
 356           (startcode == PRIVATE_STREAM_2) ||
 357           (startcode == 0x1fd)))
 358         goto redo;
 359     if (ppos) {
 360         *ppos = avio_tell(s->pb) - 4;
 361     }
 362     len = avio_rb16(s->pb);
 363     pts =
 364     dts = AV_NOPTS_VALUE;
 365     if (startcode != PRIVATE_STREAM_2)
 366     {
 367     /* stuffing */
 368     for (;;) {
 369         if (len < 1)
 370             goto error_redo;
 371         c = avio_r8(s->pb);
 372         len--;
 373         /* XXX: for MPEG-1, should test only bit 7 */
 374         if (c != 0xff)
 375             break;
 376     }
 377     if ((c & 0xc0) == 0x40) {
 378         /* buffer scale & size */
 379         avio_r8(s->pb);
 380         c    = avio_r8(s->pb);
 381         len -= 2;
 382     }
 383     if ((c & 0xe0) == 0x20) {
 384         dts  =
 385         pts  = get_pts(s->pb, c);
 386         len -= 4;
 387         if (c & 0x10) {
 388             dts  = get_pts(s->pb, -1);
 389             len -= 5;
 390         }
 391     } else if ((c & 0xc0) == 0x80) {
 392         /* mpeg 2 PES */
 393         flags      = avio_r8(s->pb);
 394         header_len = avio_r8(s->pb);
 395         len       -= 2;
 396         if (header_len > len)
 397             goto error_redo;
 398         len -= header_len;
 399         if (flags & 0x80) {
 400             dts         = pts = get_pts(s->pb, -1);
 401             header_len -= 5;
 402             if (flags & 0x40) {
 403                 dts         = get_pts(s->pb, -1);
 404                 header_len -= 5;
 405             }
 406         }
 407         if (flags & 0x3f && header_len == 0) {
 408             flags &= 0xC0;
 409             av_log(s, AV_LOG_WARNING, "Further flags set but no bytes left\n");
 410         }
 411         if (flags & 0x01) { /* PES extension */
 412             pes_ext = avio_r8(s->pb);
 413             header_len--;
 414             /* Skip PES private data, program packet sequence counter
 415              * and P-STD buffer */
 416             skip  = (pes_ext >> 4) & 0xb;
 417             skip += skip & 0x9;
 418             if (pes_ext & 0x40 || skip > header_len) {
 419                 av_log(s, AV_LOG_WARNING, "pes_ext %X is invalid\n", pes_ext);
 420                 pes_ext = skip = 0;
 421             }
 422             avio_skip(s->pb, skip);
 423             header_len -= skip;
 424
 425             if (pes_ext & 0x01) { /* PES extension 2 */
 426                 ext2_len = avio_r8(s->pb);
 427                 header_len--;
 428                 if ((ext2_len & 0x7f) > 0) {
 429                     id_ext = avio_r8(s->pb);
 430                     if ((id_ext & 0x80) == 0)
 431                         startcode = ((startcode & 0xff) << 8) | id_ext;
 432                     header_len--;
 433                 }
 434             }
 435         }
 436         if (header_len < 0)
 437             goto error_redo;
 438         avio_skip(s->pb, header_len);
 439     } else if (c != 0xf)
 440         goto redo;
 441     }
 442
 443     if (startcode == PRIVATE_STREAM_1) {
 444         int ret = ffio_ensure_seekback(s->pb, 2);
 445
 446         if (ret < 0)
 447             return ret;
 448
 449         startcode = avio_r8(s->pb);
 450         m->raw_ac3 = 0;
 451         if (startcode == 0x0b) {
 452             if (avio_r8(s->pb) == 0x77) {
 453                 startcode = 0x80;
 454                 m->raw_ac3 = 1;
 455                 avio_skip(s->pb, -2);
 456             } else {
 457                 avio_skip(s->pb, -1);
 458             }
 459         } else {
 460             len--;
 461         }
 462     }
 463     if (len < 0)
 464         goto error_redo;
 465     if (dts != AV_NOPTS_VALUE && ppos) {
 466         int i;
 467         for (i = 0; i < s->nb_streams; i++) {
 468             if (startcode == s->streams[i]->id &&
 469                 (s->pb->seekable & AVIO_SEEKABLE_NORMAL) /* index useless on streams anyway */) {
 470                 ff_reduce_index(s, i);
 471                 av_add_index_entry(s->streams[i], *ppos, dts, 0, 0,
 472                                    AVINDEX_KEYFRAME /* FIXME keyframe? */);
 473             }
 474         }
 475     }
 476
 477     *pstart_code = startcode;
 478     *ppts        = pts;
 479     *pdts        = dts;
 480     return len;
 481 }
 482
 483 static int mpegps_read_packet(AVFormatContext *s,
 484                               AVPacket *pkt)
 485 {
 486     MpegDemuxContext *m = s->priv_data;
 487     AVStream *st;
 488     FFStream *sti;
 489     int len, startcode, i, es_type, ret;
 490     int pcm_dvd = 0;
 491     int request_probe= 0;
 492     enum AVCodecID codec_id = AV_CODEC_ID_NONE;
 493     enum AVMediaType type;
 494     int64_t pts, dts, dummy_pos; // dummy_pos is needed for the index building to work
 495
 496 redo:
 497     len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts);
 498     if (len < 0)
 499         return len;
 500
 501     if (startcode >= 0x80 && startcode <= 0xcf) {
 502         if (len < 4)
 503             goto skip;
 504
 505         if (!m->raw_ac3) {
 506             /* audio: skip header */
 507             avio_skip(s->pb, 3);
 508             len -= 3;
 509             if (startcode >= 0xb0 && startcode <= 0xbf) {
 510                 /* MLP/TrueHD audio has a 4-byte header */
 511                 avio_r8(s->pb);
 512                 len--;
 513             } else if (startcode >= 0xa0 && startcode <= 0xaf) {
 514                 ret = ffio_ensure_seekback(s->pb, 3);
 515                 if (ret < 0)
 516                     return ret;
 517                 pcm_dvd = (avio_rb24(s->pb) & 0xFF) == 0x80;
 518                 avio_skip(s->pb, -3);
 519             }
 520         }
 521     }
 522
 523     /* now find stream */
 524     for (i = 0; i < s->nb_streams; i++) {
 525         st = s->streams[i];
 526         if (st->id == startcode)
 527             goto found;
 528     }
 529
 530     es_type = m->psm_es_type[startcode & 0xff];
 531     if (es_type == STREAM_TYPE_VIDEO_MPEG1) {
 532         codec_id = AV_CODEC_ID_MPEG2VIDEO;
 533         type     = AVMEDIA_TYPE_VIDEO;
 534     } else if (es_type == STREAM_TYPE_VIDEO_MPEG2) {
 535         codec_id = AV_CODEC_ID_MPEG2VIDEO;
 536         type     = AVMEDIA_TYPE_VIDEO;
 537     } else if (es_type == STREAM_TYPE_AUDIO_MPEG1 ||
 538                es_type == STREAM_TYPE_AUDIO_MPEG2) {
 539         codec_id = AV_CODEC_ID_MP3;
 540         type     = AVMEDIA_TYPE_AUDIO;
 541     } else if (es_type == STREAM_TYPE_AUDIO_AAC) {
 542         codec_id = AV_CODEC_ID_AAC;
 543         type     = AVMEDIA_TYPE_AUDIO;
 544     } else if (es_type == STREAM_TYPE_VIDEO_MPEG4) {
 545         codec_id = AV_CODEC_ID_MPEG4;
 546         type     = AVMEDIA_TYPE_VIDEO;
 547     } else if (es_type == STREAM_TYPE_VIDEO_H264) {
 548         codec_id = AV_CODEC_ID_H264;
 549         type     = AVMEDIA_TYPE_VIDEO;
 550     } else if (es_type == STREAM_TYPE_VIDEO_HEVC) {
 551         codec_id = AV_CODEC_ID_HEVC;
 552         type     = AVMEDIA_TYPE_VIDEO;
 553     } else if (es_type == STREAM_TYPE_VIDEO_VVC) {
 554         codec_id = AV_CODEC_ID_VVC;
 555         type     = AVMEDIA_TYPE_VIDEO;
 556     } else if (es_type == STREAM_TYPE_AUDIO_AC3) {
 557         codec_id = AV_CODEC_ID_AC3;
 558         type     = AVMEDIA_TYPE_AUDIO;
 559     } else if (es_type == 0x90) {
 560         codec_id = AV_CODEC_ID_PCM_ALAW;
 561         type     = AVMEDIA_TYPE_AUDIO;
 562     } else if (m->imkh_cctv && es_type == 0x91) {
 563         codec_id = AV_CODEC_ID_PCM_MULAW;
 564         type     = AVMEDIA_TYPE_AUDIO;
 565     } else if (startcode >= 0x1e0 && startcode <= 0x1ef) {
 566         static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 };
 567         unsigned char buf[8];
 568
 569         ret = ffio_read_size(s->pb, buf, 8);
 570         if (ret < 0)
 571             return ret;
 572         avio_seek(s->pb, -8, SEEK_CUR);
 573         if (!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1))
 574             codec_id = AV_CODEC_ID_CAVS;
 575         else
 576             request_probe= 1;
 577         type = AVMEDIA_TYPE_VIDEO;
 578     } else if (startcode == PRIVATE_STREAM_2) {
 579         type = AVMEDIA_TYPE_DATA;
 580         codec_id = AV_CODEC_ID_DVD_NAV;
 581     } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
 582         type     = AVMEDIA_TYPE_AUDIO;
 583         if (m->sofdec > 0) {
 584             codec_id = AV_CODEC_ID_ADPCM_ADX;
 585             // Auto-detect AC-3
 586             request_probe = 50;
 587         } else if (m->imkh_cctv && startcode == 0x1c0 && len > 80) {
 588             codec_id = AV_CODEC_ID_PCM_ALAW;
 589             request_probe = 50;
 590         } else {
 591             codec_id = AV_CODEC_ID_MP2;
 592             if (m->imkh_cctv)
 593                 request_probe = 25;
 594         }
 595     } else if (startcode >= 0x80 && startcode <= 0x87) {
 596         type     = AVMEDIA_TYPE_AUDIO;
 597         codec_id = AV_CODEC_ID_AC3;
 598     } else if ((startcode >= 0x88 && startcode <= 0x8f) ||
 599                (startcode >= 0x98 && startcode <= 0x9f)) {
 600         /* 0x90 - 0x97 is reserved for SDDS in DVD specs */
 601         type     = AVMEDIA_TYPE_AUDIO;
 602         codec_id = AV_CODEC_ID_DTS;
 603     } else if (startcode >= 0xa0 && startcode <= 0xaf) {
 604         type     = AVMEDIA_TYPE_AUDIO;
 605         if (!pcm_dvd) {
 606             codec_id = AV_CODEC_ID_MLP;
 607         } else {
 608             codec_id = AV_CODEC_ID_PCM_DVD;
 609         }
 610     } else if (startcode >= 0xb0 && startcode <= 0xbf) {
 611         type     = AVMEDIA_TYPE_AUDIO;
 612         codec_id = AV_CODEC_ID_TRUEHD;
 613     } else if (startcode >= 0xc0 && startcode <= 0xcf) {
 614         /* Used for both AC-3 and E-AC-3 in EVOB files */
 615         type     = AVMEDIA_TYPE_AUDIO;
 616         codec_id = AV_CODEC_ID_AC3;
 617     } else if (startcode >= 0x20 && startcode <= 0x3f) {
 618         type     = AVMEDIA_TYPE_SUBTITLE;
 619         codec_id = AV_CODEC_ID_DVD_SUBTITLE;
 620     } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) {
 621         type     = AVMEDIA_TYPE_VIDEO;
 622         codec_id = AV_CODEC_ID_VC1;
 623     } else if (startcode == 0x69 || startcode == 0x49) {
 624         type     = AVMEDIA_TYPE_SUBTITLE;
 625         codec_id = AV_CODEC_ID_IVTV_VBI;
 626     } else {
 627 skip:
 628         /* skip packet */
 629         avio_skip(s->pb, len);
 630         goto redo;
 631     }
 632     /* no stream found: add a new stream */
 633     st = avformat_new_stream(s, NULL);
 634     if (!st)
 635         goto skip;
 636     sti = ffstream(st);
 637     st->id                = startcode;
 638     st->codecpar->codec_type = type;
 639     st->codecpar->codec_id   = codec_id;
 640     if (   st->codecpar->codec_id == AV_CODEC_ID_PCM_MULAW
 641         || st->codecpar->codec_id == AV_CODEC_ID_PCM_ALAW) {
 642         st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
 643         st->codecpar->sample_rate = 8000;
 644     }
 645     sti->request_probe = request_probe;
 646     sti->need_parsing  = AVSTREAM_PARSE_FULL;
 647
 648 found:
 649     if (st->discard >= AVDISCARD_ALL)
 650         goto skip;
 651     if (startcode >= 0xa0 && startcode <= 0xaf) {
 652       if (st->codecpar->codec_id == AV_CODEC_ID_MLP) {
 653             if (len < 6)
 654                 goto skip;
 655             avio_skip(s->pb, 6);
 656             len -=6;
 657       }
 658     }
 659     ret = av_get_packet(s->pb, pkt, len);
 660
 661     pkt->pts          = pts;
 662     pkt->dts          = dts;
 663     pkt->pos          = dummy_pos;
 664     pkt->stream_index = st->index;
 665
 666     if (s->debug & FF_FDEBUG_TS)
 667         av_log(s, AV_LOG_DEBUG, "%d: pts=%0.3f dts=%0.3f size=%d\n",
 668             pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0,
 669             pkt->size);
 670
 671     return (ret < 0) ? ret : 0;
 672 }
 673
 674 static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,
 675                                int64_t *ppos, int64_t pos_limit)
 676 {
 677     int len, startcode;
 678     int64_t pos, pts, dts;
 679
 680     pos = *ppos;
 681     if (avio_seek(s->pb, pos, SEEK_SET) < 0)
 682         return AV_NOPTS_VALUE;
 683
 684     for (;;) {
 685         len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts);
 686         if (len < 0) {
 687             if (s->debug & FF_FDEBUG_TS)
 688                 av_log(s, AV_LOG_DEBUG, "none (ret=%d)\n", len);
 689             return AV_NOPTS_VALUE;
 690         }
 691         if (startcode == s->streams[stream_index]->id &&
 692             dts != AV_NOPTS_VALUE) {
 693             break;
 694         }
 695         avio_skip(s->pb, len);
 696     }
 697     if (s->debug & FF_FDEBUG_TS)
 698         av_log(s, AV_LOG_DEBUG, "pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n",
 699             pos, dts, dts / 90000.0);
 700     *ppos = pos;
 701     return dts;
 702 }
 703
 704 const FFInputFormat ff_mpegps_demuxer = {
 705     .p.name         = "mpeg",
 706     .p.long_name    = NULL_IF_CONFIG_SMALL("MPEG-PS (MPEG-2 Program Stream)"),
 707     .p.flags        = AVFMT_SHOW_IDS | AVFMT_TS_DISCONT,
 708     .priv_data_size = sizeof(MpegDemuxContext),
 709     .read_probe     = mpegps_probe,
 710     .read_header    = mpegps_read_header,
 711     .read_packet    = mpegps_read_packet,
 712     .read_timestamp = mpegps_read_dts,
 713 };
 714
 715 #if CONFIG_VOBSUB_DEMUXER
 716
 717 #include "subtitles.h"
 718 #include "libavutil/avassert.h"
 719 #include "libavutil/bprint.h"
 720 #include "libavutil/opt.h"
 721
 722 #define REF_STRING "# VobSub index file,"
 723 #define MAX_LINE_SIZE 2048
 724
 725 typedef struct VobSubDemuxContext {
 726     const AVClass *class;
 727     AVFormatContext *sub_ctx;
 728     FFDemuxSubtitlesQueue q[32];
 729     char *sub_name;
 730 } VobSubDemuxContext;
 731
 732 static int vobsub_probe(const AVProbeData *p)
 733 {
 734     if (!strncmp(p->buf, REF_STRING, sizeof(REF_STRING) - 1))
 735         return AVPROBE_SCORE_MAX;
 736     return 0;
 737 }
 738
 739 static int vobsub_read_close(AVFormatContext *s)
 740 {
 741     VobSubDemuxContext *vobsub = s->priv_data;
 742     int i;
 743
 744     for (i = 0; i < s->nb_streams; i++)
 745         ff_subtitles_queue_clean(&vobsub->q[i]);
 746     avformat_close_input(&vobsub->sub_ctx);
 747     return 0;
 748 }
 749
 750 static int vobsub_read_header(AVFormatContext *s)
 751 {
 752     int i, ret = 0, header_parsed = 0, langidx = 0;
 753     VobSubDemuxContext *vobsub = s->priv_data;
 754     const AVInputFormat *iformat;
 755     size_t fname_len;
 756     AVBPrint header;
 757     int64_t delay = 0;
 758     AVStream *st = NULL;
 759     int stream_id = -1;
 760     char id[64] = {0};
 761     char alt[MAX_LINE_SIZE] = {0};
 762
 763     if (!vobsub->sub_name) {
 764         char *ext;
 765         vobsub->sub_name = av_strdup(s->url);
 766         if (!vobsub->sub_name) {
 767             return AVERROR(ENOMEM);
 768         }
 769
 770         fname_len = strlen(vobsub->sub_name);
 771         ext = vobsub->sub_name - 3 + fname_len;
 772         if (fname_len < 4 || *(ext - 1) != '.') {
 773             av_log(s, AV_LOG_ERROR, "The input index filename is too short "
 774                    "to guess the associated .SUB file\n");
 775             return AVERROR_INVALIDDATA;
 776         }
 777         memcpy(ext, !strncmp(ext, "IDX", 3) ? "SUB" : "sub", 3);
 778         av_log(s, AV_LOG_VERBOSE, "IDX/SUB: %s -> %s\n", s->url, vobsub->sub_name);
 779     }
 780
 781     if (!(iformat = av_find_input_format("mpeg"))) {
 782         return AVERROR_DEMUXER_NOT_FOUND;
 783     }
 784
 785     vobsub->sub_ctx = avformat_alloc_context();
 786     if (!vobsub->sub_ctx) {
 787         return AVERROR(ENOMEM);
 788     }
 789
 790     if ((ret = ff_copy_whiteblacklists(vobsub->sub_ctx, s)) < 0)
 791         return ret;
 792
 793     ret = avformat_open_input(&vobsub->sub_ctx, vobsub->sub_name, iformat, NULL);
 794     if (ret < 0) {
 795         av_log(s, AV_LOG_ERROR, "Unable to open %s as MPEG subtitles\n", vobsub->sub_name);
 796         return ret;
 797     }
 798
 799     av_bprint_init(&header, 0, INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE);
 800
 801     while (!avio_feof(s->pb)) {
 802         char line[MAX_LINE_SIZE];
 803         int len = ff_get_line(s->pb, line, sizeof(line));
 804
 805         if (!len)
 806             break;
 807
 808         line[strcspn(line, "\r\n")] = 0;
 809
 810         if (!strncmp(line, "id:", 3)) {
 811             if (sscanf(line, "id: %63[^,], index: %u", id, &stream_id) != 2) {
 812                 av_log(s, AV_LOG_WARNING, "Unable to parse index line '%s', "
 813                        "assuming 'id: und, index: 0'\n", line);
 814                 strcpy(id, "und");
 815                 stream_id = 0;
 816             }
 817
 818             if (stream_id >= FF_ARRAY_ELEMS(vobsub->q)) {
 819                 av_log(s, AV_LOG_ERROR, "Maximum number of subtitles streams reached\n");
 820                 ret = AVERROR(EINVAL);
 821                 goto end;
 822             }
 823
 824             header_parsed = 1;
 825             alt[0] = '\0';
 826             /* We do not create the stream immediately to avoid adding empty
 827              * streams. See the following timestamp entry. */
 828
 829             av_log(s, AV_LOG_DEBUG, "IDX stream[%d] id=%s\n", stream_id, id);
 830
 831         } else if (!strncmp(line, "timestamp:", 10)) {
 832             AVPacket *sub;
 833             int hh, mm, ss, ms;
 834             int64_t pos, timestamp;
 835             const char *p = line + 10;
 836
 837             if (stream_id == -1) {
 838                 av_log(s, AV_LOG_ERROR, "Timestamp declared before any stream\n");
 839                 ret = AVERROR_INVALIDDATA;
 840                 goto end;
 841             }
 842
 843             if (!st || st->id != stream_id) {
 844                 st = avformat_new_stream(s, NULL);
 845                 if (!st) {
 846                     ret = AVERROR(ENOMEM);
 847                     goto end;
 848                 }
 849                 st->id = stream_id;
 850                 st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
 851                 st->codecpar->codec_id   = AV_CODEC_ID_DVD_SUBTITLE;
 852                 avpriv_set_pts_info(st, 64, 1, 1000);
 853                 av_dict_set(&st->metadata, "language", id, 0);
 854                 if (alt[0])
 855                     av_dict_set(&st->metadata, "title", alt, 0);
 856             }
 857
 858             if (sscanf(p, "%02d:%02d:%02d:%03d, filepos: %"SCNx64,
 859                        &hh, &mm, &ss, &ms, &pos) != 5) {
 860                 av_log(s, AV_LOG_ERROR, "Unable to parse timestamp line '%s', "
 861                        "abort parsing\n", line);
 862                 ret = AVERROR_INVALIDDATA;
 863                 goto end;
 864             }
 865             timestamp = (hh*3600LL + mm*60LL + ss) * 1000LL + ms + delay;
 866             timestamp = av_rescale_q(timestamp, av_make_q(1, 1000), st->time_base);
 867
 868             sub = ff_subtitles_queue_insert(&vobsub->q[s->nb_streams - 1], "", 0, 0);
 869             if (!sub) {
 870                 ret = AVERROR(ENOMEM);
 871                 goto end;
 872             }
 873             sub->pos = pos;
 874             sub->pts = timestamp;
 875             sub->stream_index = s->nb_streams - 1;
 876
 877         } else if (!strncmp(line, "alt:", 4)) {
 878             const char *p = line + 4;
 879
 880             while (*p == ' ')
 881                 p++;
 882             av_log(s, AV_LOG_DEBUG, "IDX stream[%d] name=%s\n", stream_id, p);
 883             av_strlcpy(alt, p, sizeof(alt));
 884             header_parsed = 1;
 885
 886         } else if (!strncmp(line, "delay:", 6)) {
 887             int sign = 1, hh = 0, mm = 0, ss = 0, ms = 0;
 888             const char *p = line + 6;
 889
 890             while (*p == ' ')
 891                 p++;
 892             if (*p == '-' || *p == '+') {
 893                 sign = *p == '-' ? -1 : 1;
 894                 p++;
 895             }
 896             sscanf(p, "%d:%d:%d:%d", &hh, &mm, &ss, &ms);
 897             delay = ((hh*3600LL + mm*60LL + ss) * 1000LL + ms) * sign;
 898
 899         } else if (!strncmp(line, "langidx:", 8)) {
 900             const char *p = line + 8;
 901
 902             if (sscanf(p, "%d", &langidx) != 1)
 903                 av_log(s, AV_LOG_ERROR, "Invalid langidx specified\n");
 904
 905         } else if (!header_parsed) {
 906             if (line[0] && line[0] != '#')
 907                 av_bprintf(&header, "%s\n", line);
 908         }
 909     }
 910
 911     if (langidx < s->nb_streams)
 912         s->streams[langidx]->disposition |= AV_DISPOSITION_DEFAULT;
 913
 914     for (i = 0; i < s->nb_streams; i++) {
 915         vobsub->q[i].sort = SUB_SORT_POS_TS;
 916         vobsub->q[i].keep_duplicates = 1;
 917         ff_subtitles_queue_finalize(s, &vobsub->q[i]);
 918     }
 919
 920     if (!av_bprint_is_complete(&header)) {
 921         ret = AVERROR(ENOMEM);
 922         goto end;
 923     }
 924     for (i = 0; i < s->nb_streams; i++) {
 925         AVCodecParameters *par = s->streams[i]->codecpar;
 926         ret = ff_alloc_extradata(par, header.len);
 927         if (ret < 0) {
 928             goto end;
 929         }
 930         memcpy(par->extradata, header.str, header.len);
 931     }
 932 end:
 933     av_bprint_finalize(&header, NULL);
 934     return ret;
 935 }
 936
 937 static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)
 938 {
 939     VobSubDemuxContext *vobsub = s->priv_data;
 940     FFDemuxSubtitlesQueue *q;
 941     AVIOContext *pb = vobsub->sub_ctx->pb;
 942     int ret, psize, total_read = 0, i;
 943
 944     int64_t min_ts = INT64_MAX;
 945     int sid = 0;
 946     for (i = 0; i < s->nb_streams; i++) {
 947         FFDemuxSubtitlesQueue *tmpq = &vobsub->q[i];
 948         int64_t ts;
 949         av_assert0(tmpq->nb_subs);
 950
 951         if (tmpq->current_sub_idx >= tmpq->nb_subs)
 952             continue;
 953
 954         ts = tmpq->subs[tmpq->current_sub_idx]->pts;
 955         if (ts < min_ts) {
 956             min_ts = ts;
 957             sid = i;
 958         }
 959     }
 960     q = &vobsub->q[sid];
 961     /* The returned packet will have size zero,
 962      * so that it can be directly used with av_grow_packet. */
 963     ret = ff_subtitles_queue_read_packet(q, pkt);
 964     if (ret < 0)
 965         return ret;
 966
 967     /* compute maximum packet size using the next packet position. This is
 968      * useful when the len in the header is non-sense */
 969     if (q->current_sub_idx < q->nb_subs) {
 970         psize = q->subs[q->current_sub_idx]->pos - pkt->pos;
 971     } else {
 972         int64_t fsize = avio_size(pb);
 973         psize = fsize < 0 ? 0xffff : fsize - pkt->pos;
 974     }
 975
 976     avio_seek(pb, pkt->pos, SEEK_SET);
 977
 978     do {
 979         int n, to_read, startcode;
 980         int64_t pts, dts;
 981         int64_t old_pos = avio_tell(pb), new_pos;
 982         int pkt_size;
 983
 984         ret = mpegps_read_pes_header(vobsub->sub_ctx, NULL, &startcode, &pts, &dts);
 985         if (ret < 0) {
 986             if (pkt->size) // raise packet even if incomplete
 987                 break;
 988             return ret;
 989         }
 990         to_read = ret & 0xffff;
 991         new_pos = avio_tell(pb);
 992         pkt_size = ret + (new_pos - old_pos);
 993
 994         /* this prevents reads above the current packet */
 995         if (total_read + pkt_size > psize)
 996             break;
 997         total_read += pkt_size;
 998
 999         /* the current chunk doesn't match the stream index (unlikely) */
1000         if ((startcode & 0x1f) != s->streams[pkt->stream_index]->id)
1001             break;
1002
1003         ret = av_grow_packet(pkt, to_read);
1004         if (ret < 0)
1005             return ret;
1006
1007         n = avio_read(pb, pkt->data + (pkt->size - to_read), to_read);
1008         if (n < to_read)
1009             pkt->size -= to_read - n;
1010     } while (total_read < psize);
1011
1012     return 0;
1013 }
1014
1015 static int vobsub_read_seek(AVFormatContext *s, int stream_index,
1016                             int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
1017 {
1018     VobSubDemuxContext *vobsub = s->priv_data;
1019
1020     /* Rescale requested timestamps based on the first stream (timebase is the
1021      * same for all subtitles stream within a .idx/.sub). Rescaling is done just
1022      * like in avformat_seek_file(). */
1023     if (stream_index == -1 && s->nb_streams != 1) {
1024         int i, ret = 0;
1025         AVRational time_base = s->streams[0]->time_base;
1026         ts = av_rescale_q(ts, AV_TIME_BASE_Q, time_base);
1027         min_ts = av_rescale_rnd(min_ts, time_base.den,
1028                                 time_base.num * (int64_t)AV_TIME_BASE,
1029                                 AV_ROUND_UP   | AV_ROUND_PASS_MINMAX);
1030         max_ts = av_rescale_rnd(max_ts, time_base.den,
1031                                 time_base.num * (int64_t)AV_TIME_BASE,
1032                                 AV_ROUND_DOWN | AV_ROUND_PASS_MINMAX);
1033         for (i = 0; i < s->nb_streams; i++) {
1034             int r = ff_subtitles_queue_seek(&vobsub->q[i], s, stream_index,
1035                                             min_ts, ts, max_ts, flags);
1036             if (r < 0)
1037                 ret = r;
1038         }
1039         return ret;
1040     }
1041
1042     if (stream_index == -1) // only 1 stream
1043         stream_index = 0;
1044     return ff_subtitles_queue_seek(&vobsub->q[stream_index], s, stream_index,
1045                                    min_ts, ts, max_ts, flags);
1046 }
1047
1048 static const AVOption options[] = {
1049     { "sub_name", "URI for .sub file", offsetof(VobSubDemuxContext, sub_name), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, AV_OPT_FLAG_DECODING_PARAM },
1050     { NULL }
1051 };
1052
1053 static const AVClass vobsub_demuxer_class = {
1054     .class_name = "vobsub",
1055     .item_name  = av_default_item_name,
1056     .option     = options,
1057     .version    = LIBAVUTIL_VERSION_INT,
1058 };
1059
1060 const FFInputFormat ff_vobsub_demuxer = {
1061     .p.name         = "vobsub",
1062     .p.long_name    = NULL_IF_CONFIG_SMALL("VobSub subtitle format"),
1063     .p.flags        = AVFMT_SHOW_IDS,
1064     .p.extensions   = "idx",
1065     .p.priv_class   = &vobsub_demuxer_class,
1066     .priv_data_size = sizeof(VobSubDemuxContext),
1067     .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,
1068     .read_probe     = vobsub_probe,
1069     .read_header    = vobsub_read_header,
1070     .read_packet    = vobsub_read_packet,
1071     .read_seek2     = vobsub_read_seek,
1072     .read_close     = vobsub_read_close,
1073 };
1074 #endif