libavformat/concatdec.c

   1 /*
   2  * Copyright (c) 2012 Nicolas George
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public License
   8  * as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include "libavutil/avassert.h"
  22 #include "libavutil/avstring.h"
  23 #include "libavutil/bprint.h"
  24 #include "libavutil/intreadwrite.h"
  25 #include "libavutil/opt.h"
  26 #include "libavutil/parseutils.h"
  27 #include "libavutil/timestamp.h"
  28 #include "avformat.h"
  29 #include "internal.h"
  30 #include "url.h"
  31
  32 typedef enum ConcatMatchMode {
  33     MATCH_ONE_TO_ONE,
  34     MATCH_EXACT_ID,
  35 } ConcatMatchMode;
  36
  37 typedef struct ConcatStream {
  38     AVBSFContext *bsf;
  39     int out_stream_index;
  40 } ConcatStream;
  41
  42 typedef struct {
  43     char *url;
  44     int64_t start_time;
  45     int64_t file_start_time;
  46     int64_t file_inpoint;
  47     int64_t duration;
  48     int64_t user_duration;
  49     int64_t next_dts;
  50     ConcatStream *streams;
  51     int64_t inpoint;
  52     int64_t outpoint;
  53     AVDictionary *metadata;
  54     int nb_streams;
  55 } ConcatFile;
  56
  57 typedef struct {
  58     AVClass *class;
  59     ConcatFile *files;
  60     ConcatFile *cur_file;
  61     unsigned nb_files;
  62     AVFormatContext *avf;
  63     int safe;
  64     int seekable;
  65     int eof;
  66     ConcatMatchMode stream_match_mode;
  67     unsigned auto_convert;
  68     int segment_time_metadata;
  69 } ConcatContext;
  70
  71 static int concat_probe(const AVProbeData *probe)
  72 {
  73     return memcmp(probe->buf, "ffconcat version 1.0", 20) ?
  74            0 : AVPROBE_SCORE_MAX;
  75 }
  76
  77 static char *get_keyword(uint8_t **cursor)
  78 {
  79     char *ret = *cursor += strspn(*cursor, SPACE_CHARS);
  80     *cursor += strcspn(*cursor, SPACE_CHARS);
  81     if (**cursor) {
  82         *((*cursor)++) = 0;
  83         *cursor += strspn(*cursor, SPACE_CHARS);
  84     }
  85     return ret;
  86 }
  87
  88 static int safe_filename(const char *f)
  89 {
  90     const char *start = f;
  91
  92     for (; *f; f++) {
  93         /* A-Za-z0-9_- */
  94         if (!((unsigned)((*f | 32) - 'a') < 26 ||
  95               (unsigned)(*f - '0') < 10 || *f == '_' || *f == '-')) {
  96             if (f == start)
  97                 return 0;
  98             else if (*f == '/')
  99                 start = f + 1;
 100             else if (*f != '.')
 101                 return 0;
 102         }
 103     }
 104     return 1;
 105 }
 106
 107 #define FAIL(retcode) do { ret = (retcode); goto fail; } while(0)
 108
 109 static int add_file(AVFormatContext *avf, char *filename, ConcatFile **rfile,
 110                     unsigned *nb_files_alloc)
 111 {
 112     ConcatContext *cat = avf->priv_data;
 113     ConcatFile *file;
 114     char *url = NULL;
 115     const char *proto;
 116     const char *ptr;
 117     size_t url_len;
 118     int ret;
 119
 120     if (cat->safe > 0 && !safe_filename(filename)) {
 121         av_log(avf, AV_LOG_ERROR, "Unsafe file name '%s'\n", filename);
 122         FAIL(AVERROR(EPERM));
 123     }
 124
 125     proto = avio_find_protocol_name(filename);
 126     if (proto && av_strstart(filename, proto, &ptr) &&
 127         (*ptr == ':' || *ptr == ',')) {
 128         url = filename;
 129         filename = NULL;
 130     } else {
 131         url_len = strlen(avf->url) + strlen(filename) + 16;
 132         if (!(url = av_malloc(url_len)))
 133             FAIL(AVERROR(ENOMEM));
 134         ff_make_absolute_url(url, url_len, avf->url, filename);
 135         av_freep(&filename);
 136     }
 137
 138     if (cat->nb_files >= *nb_files_alloc) {
 139         size_t n = FFMAX(*nb_files_alloc * 2, 16);
 140         ConcatFile *new_files;
 141         if (n <= cat->nb_files || n > SIZE_MAX / sizeof(*cat->files) ||
 142             !(new_files = av_realloc(cat->files, n * sizeof(*cat->files))))
 143             FAIL(AVERROR(ENOMEM));
 144         cat->files = new_files;
 145         *nb_files_alloc = n;
 146     }
 147
 148     file = &cat->files[cat->nb_files++];
 149     memset(file, 0, sizeof(*file));
 150     *rfile = file;
 151
 152     file->url        = url;
 153     file->start_time = AV_NOPTS_VALUE;
 154     file->duration   = AV_NOPTS_VALUE;
 155     file->next_dts   = AV_NOPTS_VALUE;
 156     file->inpoint    = AV_NOPTS_VALUE;
 157     file->outpoint   = AV_NOPTS_VALUE;
 158     file->user_duration = AV_NOPTS_VALUE;
 159
 160     return 0;
 161
 162 fail:
 163     av_free(url);
 164     av_free(filename);
 165     return ret;
 166 }
 167
 168 static int copy_stream_props(AVStream *st, AVStream *source_st)
 169 {
 170     int ret;
 171
 172     if (st->codecpar->codec_id || !source_st->codecpar->codec_id) {
 173         if (st->codecpar->extradata_size < source_st->codecpar->extradata_size) {
 174             ret = ff_alloc_extradata(st->codecpar,
 175                                      source_st->codecpar->extradata_size);
 176             if (ret < 0)
 177                 return ret;
 178         }
 179         memcpy(st->codecpar->extradata, source_st->codecpar->extradata,
 180                source_st->codecpar->extradata_size);
 181         return 0;
 182     }
 183     if ((ret = avcodec_parameters_copy(st->codecpar, source_st->codecpar)) < 0)
 184         return ret;
 185     st->r_frame_rate        = source_st->r_frame_rate;
 186     st->avg_frame_rate      = source_st->avg_frame_rate;
 187     st->sample_aspect_ratio = source_st->sample_aspect_ratio;
 188     avpriv_set_pts_info(st, 64, source_st->time_base.num, source_st->time_base.den);
 189
 190     av_dict_copy(&st->metadata, source_st->metadata, 0);
 191     return 0;
 192 }
 193
 194 static int detect_stream_specific(AVFormatContext *avf, int idx)
 195 {
 196     ConcatContext *cat = avf->priv_data;
 197     AVStream *st = cat->avf->streams[idx];
 198     ConcatStream *cs = &cat->cur_file->streams[idx];
 199     const AVBitStreamFilter *filter;
 200     AVBSFContext *bsf;
 201     int ret;
 202
 203     if (cat->auto_convert && st->codecpar->codec_id == AV_CODEC_ID_H264) {
 204         if (!st->codecpar->extradata_size                                                ||
 205             (st->codecpar->extradata_size >= 3 && AV_RB24(st->codecpar->extradata) == 1) ||
 206             (st->codecpar->extradata_size >= 4 && AV_RB32(st->codecpar->extradata) == 1))
 207             return 0;
 208         av_log(cat->avf, AV_LOG_INFO,
 209                "Auto-inserting h264_mp4toannexb bitstream filter\n");
 210         filter = av_bsf_get_by_name("h264_mp4toannexb");
 211         if (!filter) {
 212             av_log(avf, AV_LOG_ERROR, "h264_mp4toannexb bitstream filter "
 213                    "required for H.264 streams\n");
 214             return AVERROR_BSF_NOT_FOUND;
 215         }
 216         ret = av_bsf_alloc(filter, &bsf);
 217         if (ret < 0)
 218             return ret;
 219         cs->bsf = bsf;
 220
 221         ret = avcodec_parameters_copy(bsf->par_in, st->codecpar);
 222         if (ret < 0)
 223            return ret;
 224
 225         ret = av_bsf_init(bsf);
 226         if (ret < 0)
 227             return ret;
 228
 229         ret = avcodec_parameters_copy(st->codecpar, bsf->par_out);
 230         if (ret < 0)
 231             return ret;
 232     }
 233     return 0;
 234 }
 235
 236 static int match_streams_one_to_one(AVFormatContext *avf)
 237 {
 238     ConcatContext *cat = avf->priv_data;
 239     AVStream *st;
 240     int i, ret;
 241
 242     for (i = cat->cur_file->nb_streams; i < cat->avf->nb_streams; i++) {
 243         if (i < avf->nb_streams) {
 244             st = avf->streams[i];
 245         } else {
 246             if (!(st = avformat_new_stream(avf, NULL)))
 247                 return AVERROR(ENOMEM);
 248         }
 249         if ((ret = copy_stream_props(st, cat->avf->streams[i])) < 0)
 250             return ret;
 251         cat->cur_file->streams[i].out_stream_index = i;
 252     }
 253     return 0;
 254 }
 255
 256 static int match_streams_exact_id(AVFormatContext *avf)
 257 {
 258     ConcatContext *cat = avf->priv_data;
 259     AVStream *st;
 260     int i, j, ret;
 261
 262     for (i = cat->cur_file->nb_streams; i < cat->avf->nb_streams; i++) {
 263         st = cat->avf->streams[i];
 264         for (j = 0; j < avf->nb_streams; j++) {
 265             if (avf->streams[j]->id == st->id) {
 266                 av_log(avf, AV_LOG_VERBOSE,
 267                        "Match slave stream #%d with stream #%d id 0x%x\n",
 268                        i, j, st->id);
 269                 if ((ret = copy_stream_props(avf->streams[j], st)) < 0)
 270                     return ret;
 271                 cat->cur_file->streams[i].out_stream_index = j;
 272             }
 273         }
 274     }
 275     return 0;
 276 }
 277
 278 static int match_streams(AVFormatContext *avf)
 279 {
 280     ConcatContext *cat = avf->priv_data;
 281     ConcatStream *map;
 282     int i, ret;
 283
 284     if (cat->cur_file->nb_streams >= cat->avf->nb_streams)
 285         return 0;
 286     map = av_realloc(cat->cur_file->streams,
 287                      cat->avf->nb_streams * sizeof(*map));
 288     if (!map)
 289         return AVERROR(ENOMEM);
 290     cat->cur_file->streams = map;
 291     memset(map + cat->cur_file->nb_streams, 0,
 292            (cat->avf->nb_streams - cat->cur_file->nb_streams) * sizeof(*map));
 293
 294     for (i = cat->cur_file->nb_streams; i < cat->avf->nb_streams; i++) {
 295         map[i].out_stream_index = -1;
 296         if ((ret = detect_stream_specific(avf, i)) < 0)
 297             return ret;
 298     }
 299     switch (cat->stream_match_mode) {
 300     case MATCH_ONE_TO_ONE:
 301         ret = match_streams_one_to_one(avf);
 302         break;
 303     case MATCH_EXACT_ID:
 304         ret = match_streams_exact_id(avf);
 305         break;
 306     default:
 307         ret = AVERROR_BUG;
 308     }
 309     if (ret < 0)
 310         return ret;
 311     cat->cur_file->nb_streams = cat->avf->nb_streams;
 312     return 0;
 313 }
 314
 315 static int64_t get_best_effort_duration(ConcatFile *file, AVFormatContext *avf)
 316 {
 317     if (file->user_duration != AV_NOPTS_VALUE)
 318         return file->user_duration;
 319     if (file->outpoint != AV_NOPTS_VALUE)
 320         return av_sat_sub64(file->outpoint, file->file_inpoint);
 321     if (avf->duration > 0)
 322         return avf->duration - (file->file_inpoint - file->file_start_time);
 323     if (file->next_dts != AV_NOPTS_VALUE)
 324         return file->next_dts - file->file_inpoint;
 325     return AV_NOPTS_VALUE;
 326 }
 327
 328 static int open_file(AVFormatContext *avf, unsigned fileno)
 329 {
 330     ConcatContext *cat = avf->priv_data;
 331     ConcatFile *file = &cat->files[fileno];
 332     int ret;
 333
 334     if (cat->avf)
 335         avformat_close_input(&cat->avf);
 336
 337     cat->avf = avformat_alloc_context();
 338     if (!cat->avf)
 339         return AVERROR(ENOMEM);
 340
 341     cat->avf->flags |= avf->flags & ~AVFMT_FLAG_CUSTOM_IO;
 342     cat->avf->interrupt_callback = avf->interrupt_callback;
 343
 344     if ((ret = ff_copy_whiteblacklists(cat->avf, avf)) < 0)
 345         return ret;
 346
 347     if ((ret = avformat_open_input(&cat->avf, file->url, NULL, NULL)) < 0 ||
 348         (ret = avformat_find_stream_info(cat->avf, NULL)) < 0) {
 349         av_log(avf, AV_LOG_ERROR, "Impossible to open '%s'\n", file->url);
 350         avformat_close_input(&cat->avf);
 351         return ret;
 352     }
 353     cat->cur_file = file;
 354     file->start_time = !fileno ? 0 :
 355                        cat->files[fileno - 1].start_time +
 356                        cat->files[fileno - 1].duration;
 357     file->file_start_time = (cat->avf->start_time == AV_NOPTS_VALUE) ? 0 : cat->avf->start_time;
 358     file->file_inpoint = (file->inpoint == AV_NOPTS_VALUE) ? file->file_start_time : file->inpoint;
 359     file->duration = get_best_effort_duration(file, cat->avf);
 360
 361     if (cat->segment_time_metadata) {
 362         av_dict_set_int(&file->metadata, "lavf.concatdec.start_time", file->start_time, 0);
 363         if (file->duration != AV_NOPTS_VALUE)
 364             av_dict_set_int(&file->metadata, "lavf.concatdec.duration", file->duration, 0);
 365     }
 366
 367     if ((ret = match_streams(avf)) < 0)
 368         return ret;
 369     if (file->inpoint != AV_NOPTS_VALUE) {
 370        if ((ret = avformat_seek_file(cat->avf, -1, INT64_MIN, file->inpoint, file->inpoint, 0)) < 0)
 371            return ret;
 372     }
 373     return 0;
 374 }
 375
 376 static int concat_read_close(AVFormatContext *avf)
 377 {
 378     ConcatContext *cat = avf->priv_data;
 379     unsigned i, j;
 380
 381     for (i = 0; i < cat->nb_files; i++) {
 382         av_freep(&cat->files[i].url);
 383         for (j = 0; j < cat->files[i].nb_streams; j++) {
 384             if (cat->files[i].streams[j].bsf)
 385                 av_bsf_free(&cat->files[i].streams[j].bsf);
 386         }
 387         av_freep(&cat->files[i].streams);
 388         av_dict_free(&cat->files[i].metadata);
 389     }
 390     if (cat->avf)
 391         avformat_close_input(&cat->avf);
 392     av_freep(&cat->files);
 393     return 0;
 394 }
 395
 396 static int concat_read_header(AVFormatContext *avf)
 397 {
 398     ConcatContext *cat = avf->priv_data;
 399     AVBPrint bp;
 400     uint8_t *cursor, *keyword;
 401     int line = 0, i;
 402     unsigned nb_files_alloc = 0;
 403     ConcatFile *file = NULL;
 404     int64_t ret, time = 0;
 405
 406     av_bprint_init(&bp, 0, AV_BPRINT_SIZE_UNLIMITED);
 407
 408     while ((ret = ff_read_line_to_bprint_overwrite(avf->pb, &bp)) >= 0) {
 409         line++;
 410         cursor = bp.str;
 411         keyword = get_keyword(&cursor);
 412         if (!*keyword || *keyword == '#')
 413             continue;
 414
 415         if (!strcmp(keyword, "file")) {
 416             char *filename = av_get_token((const char **)&cursor, SPACE_CHARS);
 417             if (!filename) {
 418                 av_log(avf, AV_LOG_ERROR, "Line %d: filename required\n", line);
 419                 FAIL(AVERROR_INVALIDDATA);
 420             }
 421             if ((ret = add_file(avf, filename, &file, &nb_files_alloc)) < 0)
 422                 goto fail;
 423         } else if (!strcmp(keyword, "duration") || !strcmp(keyword, "inpoint") || !strcmp(keyword, "outpoint")) {
 424             char *dur_str = get_keyword(&cursor);
 425             int64_t dur;
 426             if (!file) {
 427                 av_log(avf, AV_LOG_ERROR, "Line %d: %s without file\n",
 428                        line, keyword);
 429                 FAIL(AVERROR_INVALIDDATA);
 430             }
 431             if ((ret = av_parse_time(&dur, dur_str, 1)) < 0) {
 432                 av_log(avf, AV_LOG_ERROR, "Line %d: invalid %s '%s'\n",
 433                        line, keyword, dur_str);
 434                 goto fail;
 435             }
 436             if (!strcmp(keyword, "duration"))
 437                 file->user_duration = dur;
 438             else if (!strcmp(keyword, "inpoint"))
 439                 file->inpoint = dur;
 440             else if (!strcmp(keyword, "outpoint"))
 441                 file->outpoint = dur;
 442         } else if (!strcmp(keyword, "file_packet_metadata")) {
 443             char *metadata;
 444             if (!file) {
 445                 av_log(avf, AV_LOG_ERROR, "Line %d: %s without file\n",
 446                        line, keyword);
 447                 FAIL(AVERROR_INVALIDDATA);
 448             }
 449             metadata = av_get_token((const char **)&cursor, SPACE_CHARS);
 450             if (!metadata) {
 451                 av_log(avf, AV_LOG_ERROR, "Line %d: packet metadata required\n", line);
 452                 FAIL(AVERROR_INVALIDDATA);
 453             }
 454             if ((ret = av_dict_parse_string(&file->metadata, metadata, "=", "", 0)) < 0) {
 455                 av_log(avf, AV_LOG_ERROR, "Line %d: failed to parse metadata string\n", line);
 456                 av_freep(&metadata);
 457                 FAIL(AVERROR_INVALIDDATA);
 458             }
 459             av_freep(&metadata);
 460         } else if (!strcmp(keyword, "stream")) {
 461             if (!avformat_new_stream(avf, NULL))
 462                 FAIL(AVERROR(ENOMEM));
 463         } else if (!strcmp(keyword, "exact_stream_id")) {
 464             if (!avf->nb_streams) {
 465                 av_log(avf, AV_LOG_ERROR, "Line %d: exact_stream_id without stream\n",
 466                        line);
 467                 FAIL(AVERROR_INVALIDDATA);
 468             }
 469             avf->streams[avf->nb_streams - 1]->id =
 470                 strtol(get_keyword(&cursor), NULL, 0);
 471         } else if (!strcmp(keyword, "ffconcat")) {
 472             char *ver_kw  = get_keyword(&cursor);
 473             char *ver_val = get_keyword(&cursor);
 474             if (strcmp(ver_kw, "version") || strcmp(ver_val, "1.0")) {
 475                 av_log(avf, AV_LOG_ERROR, "Line %d: invalid version\n", line);
 476                 FAIL(AVERROR_INVALIDDATA);
 477             }
 478             if (cat->safe < 0)
 479                 cat->safe = 1;
 480         } else {
 481             av_log(avf, AV_LOG_ERROR, "Line %d: unknown keyword '%s'\n",
 482                    line, keyword);
 483             FAIL(AVERROR_INVALIDDATA);
 484         }
 485     }
 486     if (ret != AVERROR_EOF && ret < 0)
 487         goto fail;
 488     if (!cat->nb_files)
 489         FAIL(AVERROR_INVALIDDATA);
 490
 491     for (i = 0; i < cat->nb_files; i++) {
 492         if (cat->files[i].start_time == AV_NOPTS_VALUE)
 493             cat->files[i].start_time = time;
 494         else
 495             time = cat->files[i].start_time;
 496         if (cat->files[i].user_duration == AV_NOPTS_VALUE) {
 497             if (cat->files[i].inpoint == AV_NOPTS_VALUE || cat->files[i].outpoint == AV_NOPTS_VALUE ||
 498                 cat->files[i].outpoint - (uint64_t)cat->files[i].inpoint != av_sat_sub64(cat->files[i].outpoint, cat->files[i].inpoint)
 499             )
 500                 break;
 501             cat->files[i].user_duration = cat->files[i].outpoint - cat->files[i].inpoint;
 502         }
 503         cat->files[i].duration = cat->files[i].user_duration;
 504         if (time + (uint64_t)cat->files[i].user_duration > INT64_MAX)
 505             return AVERROR_INVALIDDATA;
 506         time += cat->files[i].user_duration;
 507     }
 508     if (i == cat->nb_files) {
 509         avf->duration = time;
 510         cat->seekable = 1;
 511     }
 512
 513     cat->stream_match_mode = avf->nb_streams ? MATCH_EXACT_ID :
 514                                                MATCH_ONE_TO_ONE;
 515     if ((ret = open_file(avf, 0)) < 0)
 516         goto fail;
 517     av_bprint_finalize(&bp, NULL);
 518     return 0;
 519
 520 fail:
 521     av_bprint_finalize(&bp, NULL);
 522     concat_read_close(avf);
 523     return ret;
 524 }
 525
 526 static int open_next_file(AVFormatContext *avf)
 527 {
 528     ConcatContext *cat = avf->priv_data;
 529     unsigned fileno = cat->cur_file - cat->files;
 530
 531     cat->cur_file->duration = get_best_effort_duration(cat->cur_file, cat->avf);
 532
 533     if (++fileno >= cat->nb_files) {
 534         cat->eof = 1;
 535         return AVERROR_EOF;
 536     }
 537     return open_file(avf, fileno);
 538 }
 539
 540 static int filter_packet(AVFormatContext *avf, ConcatStream *cs, AVPacket *pkt)
 541 {
 542     int ret;
 543
 544     if (cs->bsf) {
 545         ret = av_bsf_send_packet(cs->bsf, pkt);
 546         if (ret < 0) {
 547             av_log(avf, AV_LOG_ERROR, "h264_mp4toannexb filter "
 548                    "failed to send input packet\n");
 549             return ret;
 550         }
 551
 552         while (!ret)
 553             ret = av_bsf_receive_packet(cs->bsf, pkt);
 554
 555         if (ret < 0 && (ret != AVERROR(EAGAIN) && ret != AVERROR_EOF)) {
 556             av_log(avf, AV_LOG_ERROR, "h264_mp4toannexb filter "
 557                    "failed to receive output packet\n");
 558             return ret;
 559         }
 560     }
 561     return 0;
 562 }
 563
 564 /* Returns true if the packet dts is greater or equal to the specified outpoint. */
 565 static int packet_after_outpoint(ConcatContext *cat, AVPacket *pkt)
 566 {
 567     if (cat->cur_file->outpoint != AV_NOPTS_VALUE && pkt->dts != AV_NOPTS_VALUE) {
 568         return av_compare_ts(pkt->dts, cat->avf->streams[pkt->stream_index]->time_base,
 569                              cat->cur_file->outpoint, AV_TIME_BASE_Q) >= 0;
 570     }
 571     return 0;
 572 }
 573
 574 static int concat_read_packet(AVFormatContext *avf, AVPacket *pkt)
 575 {
 576     ConcatContext *cat = avf->priv_data;
 577     int ret;
 578     int64_t delta;
 579     ConcatStream *cs;
 580     AVStream *st;
 581
 582     if (cat->eof)
 583         return AVERROR_EOF;
 584
 585     if (!cat->avf)
 586         return AVERROR(EIO);
 587
 588     while (1) {
 589         ret = av_read_frame(cat->avf, pkt);
 590         if (ret == AVERROR_EOF) {
 591             if ((ret = open_next_file(avf)) < 0)
 592                 return ret;
 593             continue;
 594         }
 595         if (ret < 0)
 596             return ret;
 597         if ((ret = match_streams(avf)) < 0) {
 598             return ret;
 599         }
 600         if (packet_after_outpoint(cat, pkt)) {
 601             av_packet_unref(pkt);
 602             if ((ret = open_next_file(avf)) < 0)
 603                 return ret;
 604             continue;
 605         }
 606         cs = &cat->cur_file->streams[pkt->stream_index];
 607         if (cs->out_stream_index < 0) {
 608             av_packet_unref(pkt);
 609             continue;
 610         }
 611         break;
 612     }
 613     if ((ret = filter_packet(avf, cs, pkt)) < 0)
 614         return ret;
 615
 616     st = cat->avf->streams[pkt->stream_index];
 617     av_log(avf, AV_LOG_DEBUG, "file:%d stream:%d pts:%s pts_time:%s dts:%s dts_time:%s",
 618            (unsigned)(cat->cur_file - cat->files), pkt->stream_index,
 619            av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, &st->time_base),
 620            av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, &st->time_base));
 621
 622     delta = av_rescale_q(cat->cur_file->start_time - cat->cur_file->file_inpoint,
 623                          AV_TIME_BASE_Q,
 624                          cat->avf->streams[pkt->stream_index]->time_base);
 625     if (pkt->pts != AV_NOPTS_VALUE)
 626         pkt->pts += delta;
 627     if (pkt->dts != AV_NOPTS_VALUE)
 628         pkt->dts += delta;
 629     av_log(avf, AV_LOG_DEBUG, " -> pts:%s pts_time:%s dts:%s dts_time:%s\n",
 630            av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, &st->time_base),
 631            av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, &st->time_base));
 632     if (cat->cur_file->metadata) {
 633         int metadata_len;
 634         char* packed_metadata = av_packet_pack_dictionary(cat->cur_file->metadata, &metadata_len);
 635         if (!packed_metadata)
 636             return AVERROR(ENOMEM);
 637         ret = av_packet_add_side_data(pkt, AV_PKT_DATA_STRINGS_METADATA,
 638                                       packed_metadata, metadata_len);
 639         if (ret < 0) {
 640             av_freep(&packed_metadata);
 641             return ret;
 642         }
 643     }
 644
 645     if (cat->cur_file->duration == AV_NOPTS_VALUE && st->cur_dts != AV_NOPTS_VALUE) {
 646         int64_t next_dts = av_rescale_q(st->cur_dts, st->time_base, AV_TIME_BASE_Q);
 647         if (cat->cur_file->next_dts == AV_NOPTS_VALUE || next_dts > cat->cur_file->next_dts) {
 648             cat->cur_file->next_dts = next_dts;
 649         }
 650     }
 651
 652     pkt->stream_index = cs->out_stream_index;
 653     return 0;
 654 }
 655
 656 static void rescale_interval(AVRational tb_in, AVRational tb_out,
 657                              int64_t *min_ts, int64_t *ts, int64_t *max_ts)
 658 {
 659     *ts     = av_rescale_q    (*    ts, tb_in, tb_out);
 660     *min_ts = av_rescale_q_rnd(*min_ts, tb_in, tb_out,
 661                                AV_ROUND_UP   | AV_ROUND_PASS_MINMAX);
 662     *max_ts = av_rescale_q_rnd(*max_ts, tb_in, tb_out,
 663                                AV_ROUND_DOWN | AV_ROUND_PASS_MINMAX);
 664 }
 665
 666 static int try_seek(AVFormatContext *avf, int stream,
 667                     int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
 668 {
 669     ConcatContext *cat = avf->priv_data;
 670     int64_t t0 = cat->cur_file->start_time - cat->cur_file->file_inpoint;
 671
 672     ts -= t0;
 673     min_ts = min_ts == INT64_MIN ? INT64_MIN : min_ts - t0;
 674     max_ts = max_ts == INT64_MAX ? INT64_MAX : max_ts - t0;
 675     if (stream >= 0) {
 676         if (stream >= cat->avf->nb_streams)
 677             return AVERROR(EIO);
 678         rescale_interval(AV_TIME_BASE_Q, cat->avf->streams[stream]->time_base,
 679                          &min_ts, &ts, &max_ts);
 680     }
 681     return avformat_seek_file(cat->avf, stream, min_ts, ts, max_ts, flags);
 682 }
 683
 684 static int real_seek(AVFormatContext *avf, int stream,
 685                      int64_t min_ts, int64_t ts, int64_t max_ts, int flags, AVFormatContext *cur_avf)
 686 {
 687     ConcatContext *cat = avf->priv_data;
 688     int ret, left, right;
 689
 690     if (stream >= 0) {
 691         if (stream >= avf->nb_streams)
 692             return AVERROR(EINVAL);
 693         rescale_interval(avf->streams[stream]->time_base, AV_TIME_BASE_Q,
 694                          &min_ts, &ts, &max_ts);
 695     }
 696
 697     left  = 0;
 698     right = cat->nb_files;
 699
 700     /* Always support seek to start */
 701     if (ts <= 0)
 702         right = 1;
 703     else if (!cat->seekable)
 704         return AVERROR(ESPIPE); /* XXX: can we use it? */
 705
 706     while (right - left > 1) {
 707         int mid = (left + right) / 2;
 708         if (ts < cat->files[mid].start_time)
 709             right = mid;
 710         else
 711             left  = mid;
 712     }
 713
 714     if (cat->cur_file != &cat->files[left]) {
 715         if ((ret = open_file(avf, left)) < 0)
 716             return ret;
 717     } else {
 718         cat->avf = cur_avf;
 719     }
 720
 721     ret = try_seek(avf, stream, min_ts, ts, max_ts, flags);
 722     if (ret < 0 &&
 723         left < cat->nb_files - 1 &&
 724         cat->files[left + 1].start_time < max_ts) {
 725         if (cat->cur_file == &cat->files[left])
 726             cat->avf = NULL;
 727         if ((ret = open_file(avf, left + 1)) < 0)
 728             return ret;
 729         ret = try_seek(avf, stream, min_ts, ts, max_ts, flags);
 730     }
 731     return ret;
 732 }
 733
 734 static int concat_seek(AVFormatContext *avf, int stream,
 735                        int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
 736 {
 737     ConcatContext *cat = avf->priv_data;
 738     ConcatFile *cur_file_saved = cat->cur_file;
 739     AVFormatContext *cur_avf_saved = cat->avf;
 740     int ret;
 741
 742     if (flags & (AVSEEK_FLAG_BYTE | AVSEEK_FLAG_FRAME))
 743         return AVERROR(ENOSYS);
 744     cat->avf = NULL;
 745     if ((ret = real_seek(avf, stream, min_ts, ts, max_ts, flags, cur_avf_saved)) < 0) {
 746         if (cat->cur_file != cur_file_saved) {
 747             if (cat->avf)
 748                 avformat_close_input(&cat->avf);
 749         }
 750         cat->avf      = cur_avf_saved;
 751         cat->cur_file = cur_file_saved;
 752     } else {
 753         if (cat->cur_file != cur_file_saved) {
 754             avformat_close_input(&cur_avf_saved);
 755         }
 756         cat->eof = 0;
 757     }
 758     return ret;
 759 }
 760
 761 #define OFFSET(x) offsetof(ConcatContext, x)
 762 #define DEC AV_OPT_FLAG_DECODING_PARAM
 763
 764 static const AVOption options[] = {
 765     { "safe", "enable safe mode",
 766       OFFSET(safe), AV_OPT_TYPE_BOOL, {.i64 = 1}, -1, 1, DEC },
 767     { "auto_convert", "automatically convert bitstream format",
 768       OFFSET(auto_convert), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, DEC },
 769     { "segment_time_metadata", "output file segment start time and duration as packet metadata",
 770       OFFSET(segment_time_metadata), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
 771     { NULL }
 772 };
 773
 774 static const AVClass concat_class = {
 775     .class_name = "concat demuxer",
 776     .item_name  = av_default_item_name,
 777     .option     = options,
 778     .version    = LIBAVUTIL_VERSION_INT,
 779 };
 780
 781
 782 AVInputFormat ff_concat_demuxer = {
 783     .name           = "concat",
 784     .long_name      = NULL_IF_CONFIG_SMALL("Virtual concatenation script"),
 785     .priv_data_size = sizeof(ConcatContext),
 786     .read_probe     = concat_probe,
 787     .read_header    = concat_read_header,
 788     .read_packet    = concat_read_packet,
 789     .read_close     = concat_read_close,
 790     .read_seek2     = concat_seek,
 791     .priv_class     = &concat_class,
 792 };