git.sesse.net Git - ffmpeg/blob - libavformat/matroskadec.c

   1 /*
   2  * Matroska file demuxer
   3  * Copyright (c) 2003-2008 The FFmpeg Project
   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 /**
  23  * @file
  24  * Matroska file demuxer
  25  * @author Ronald Bultje <rbultje@ronald.bitfreak.net>
  26  * @author with a little help from Moritz Bunkus <moritz@bunkus.org>
  27  * @author totally reworked by Aurelien Jacobs <aurel@gnuage.org>
  28  * @see specs available on the Matroska project page: http://www.matroska.org/
  29  */
  30
  31 #include <stdio.h>
  32 #include "avformat.h"
  33 #include "internal.h"
  34 #include "avio_internal.h"
  35 /* For ff_codec_get_id(). */
  36 #include "riff.h"
  37 #include "isom.h"
  38 #include "rm.h"
  39 #include "matroska.h"
  40 #include "libavcodec/mpeg4audio.h"
  41 #include "libavutil/intfloat.h"
  42 #include "libavutil/intreadwrite.h"
  43 #include "libavutil/avstring.h"
  44 #include "libavutil/lzo.h"
  45 #include "libavutil/dict.h"
  46 #if CONFIG_ZLIB
  47 #include <zlib.h>
  48 #endif
  49 #if CONFIG_BZLIB
  50 #include <bzlib.h>
  51 #endif
  52
  53 typedef enum {
  54     EBML_NONE,
  55     EBML_UINT,
  56     EBML_FLOAT,
  57     EBML_STR,
  58     EBML_UTF8,
  59     EBML_BIN,
  60     EBML_NEST,
  61     EBML_PASS,
  62     EBML_STOP,
  63     EBML_TYPE_COUNT
  64 } EbmlType;
  65
  66 typedef const struct EbmlSyntax {
  67     uint32_t id;
  68     EbmlType type;
  69     int list_elem_size;
  70     int data_offset;
  71     union {
  72         uint64_t    u;
  73         double      f;
  74         const char *s;
  75         const struct EbmlSyntax *n;
  76     } def;
  77 } EbmlSyntax;
  78
  79 typedef struct {
  80     int nb_elem;
  81     void *elem;
  82 } EbmlList;
  83
  84 typedef struct {
  85     int      size;
  86     uint8_t *data;
  87     int64_t  pos;
  88 } EbmlBin;
  89
  90 typedef struct {
  91     uint64_t version;
  92     uint64_t max_size;
  93     uint64_t id_length;
  94     char    *doctype;
  95     uint64_t doctype_version;
  96 } Ebml;
  97
  98 typedef struct {
  99     uint64_t algo;
 100     EbmlBin  settings;
 101 } MatroskaTrackCompression;
 102
 103 typedef struct {
 104     uint64_t scope;
 105     uint64_t type;
 106     MatroskaTrackCompression compression;
 107 } MatroskaTrackEncoding;
 108
 109 typedef struct {
 110     double   frame_rate;
 111     uint64_t display_width;
 112     uint64_t display_height;
 113     uint64_t pixel_width;
 114     uint64_t pixel_height;
 115     EbmlBin color_space;
 116     uint64_t stereo_mode;
 117 } MatroskaTrackVideo;
 118
 119 typedef struct {
 120     double   samplerate;
 121     double   out_samplerate;
 122     uint64_t bitdepth;
 123     uint64_t channels;
 124
 125     /* real audio header (extracted from extradata) */
 126     int      coded_framesize;
 127     int      sub_packet_h;
 128     int      frame_size;
 129     int      sub_packet_size;
 130     int      sub_packet_cnt;
 131     int      pkt_cnt;
 132     uint64_t buf_timecode;
 133     uint8_t *buf;
 134 } MatroskaTrackAudio;
 135
 136 typedef struct {
 137     uint64_t uid;
 138     uint64_t type;
 139 } MatroskaTrackPlane;
 140
 141 typedef struct {
 142     EbmlList combine_planes;
 143 } MatroskaTrackOperation;
 144
 145 typedef struct {
 146     uint64_t num;
 147     uint64_t uid;
 148     uint64_t type;
 149     char    *name;
 150     char    *codec_id;
 151     EbmlBin  codec_priv;
 152     char    *language;
 153     double time_scale;
 154     uint64_t default_duration;
 155     uint64_t flag_default;
 156     uint64_t flag_forced;
 157     MatroskaTrackVideo video;
 158     MatroskaTrackAudio audio;
 159     MatroskaTrackOperation operation;
 160     EbmlList encodings;
 161
 162     AVStream *stream;
 163     int64_t end_timecode;
 164     int ms_compat;
 165 } MatroskaTrack;
 166
 167 typedef struct {
 168     uint64_t uid;
 169     char *filename;
 170     char *mime;
 171     EbmlBin bin;
 172
 173     AVStream *stream;
 174 } MatroskaAttachement;
 175
 176 typedef struct {
 177     uint64_t start;
 178     uint64_t end;
 179     uint64_t uid;
 180     char    *title;
 181
 182     AVChapter *chapter;
 183 } MatroskaChapter;
 184
 185 typedef struct {
 186     uint64_t track;
 187     uint64_t pos;
 188 } MatroskaIndexPos;
 189
 190 typedef struct {
 191     uint64_t time;
 192     EbmlList pos;
 193 } MatroskaIndex;
 194
 195 typedef struct {
 196     char *name;
 197     char *string;
 198     char *lang;
 199     uint64_t def;
 200     EbmlList sub;
 201 } MatroskaTag;
 202
 203 typedef struct {
 204     char    *type;
 205     uint64_t typevalue;
 206     uint64_t trackuid;
 207     uint64_t chapteruid;
 208     uint64_t attachuid;
 209 } MatroskaTagTarget;
 210
 211 typedef struct {
 212     MatroskaTagTarget target;
 213     EbmlList tag;
 214 } MatroskaTags;
 215
 216 typedef struct {
 217     uint64_t id;
 218     uint64_t pos;
 219 } MatroskaSeekhead;
 220
 221 typedef struct {
 222     uint64_t start;
 223     uint64_t length;
 224 } MatroskaLevel;
 225
 226 typedef struct {
 227     uint64_t timecode;
 228     EbmlList blocks;
 229 } MatroskaCluster;
 230
 231 typedef struct {
 232     AVFormatContext *ctx;
 233
 234     /* EBML stuff */
 235     int num_levels;
 236     MatroskaLevel levels[EBML_MAX_DEPTH];
 237     int level_up;
 238     uint32_t current_id;
 239
 240     uint64_t time_scale;
 241     double   duration;
 242     char    *title;
 243     EbmlBin date_utc;
 244     EbmlList tracks;
 245     EbmlList attachments;
 246     EbmlList chapters;
 247     EbmlList index;
 248     EbmlList tags;
 249     EbmlList seekhead;
 250
 251     /* byte position of the segment inside the stream */
 252     int64_t segment_start;
 253
 254     /* the packet queue */
 255     AVPacket **packets;
 256     int num_packets;
 257     AVPacket *prev_pkt;
 258
 259     int done;
 260
 261     /* What to skip before effectively reading a packet. */
 262     int skip_to_keyframe;
 263     uint64_t skip_to_timecode;
 264
 265     /* File has a CUES element, but we defer parsing until it is needed. */
 266     int cues_parsing_deferred;
 267
 268     int current_cluster_num_blocks;
 269     int64_t current_cluster_pos;
 270     MatroskaCluster current_cluster;
 271
 272     /* File has SSA subtitles which prevent incremental cluster parsing. */
 273     int contains_ssa;
 274 } MatroskaDemuxContext;
 275
 276 typedef struct {
 277     uint64_t duration;
 278     int64_t  reference;
 279     uint64_t non_simple;
 280     EbmlBin  bin;
 281 } MatroskaBlock;
 282
 283 static EbmlSyntax ebml_header[] = {
 284     { EBML_ID_EBMLREADVERSION,        EBML_UINT, 0, offsetof(Ebml,version), {.u=EBML_VERSION} },
 285     { EBML_ID_EBMLMAXSIZELENGTH,      EBML_UINT, 0, offsetof(Ebml,max_size), {.u=8} },
 286     { EBML_ID_EBMLMAXIDLENGTH,        EBML_UINT, 0, offsetof(Ebml,id_length), {.u=4} },
 287     { EBML_ID_DOCTYPE,                EBML_STR,  0, offsetof(Ebml,doctype), {.s="(none)"} },
 288     { EBML_ID_DOCTYPEREADVERSION,     EBML_UINT, 0, offsetof(Ebml,doctype_version), {.u=1} },
 289     { EBML_ID_EBMLVERSION,            EBML_NONE },
 290     { EBML_ID_DOCTYPEVERSION,         EBML_NONE },
 291     { 0 }
 292 };
 293
 294 static EbmlSyntax ebml_syntax[] = {
 295     { EBML_ID_HEADER,                 EBML_NEST, 0, 0, {.n=ebml_header} },
 296     { 0 }
 297 };
 298
 299 static EbmlSyntax matroska_info[] = {
 300     { MATROSKA_ID_TIMECODESCALE,      EBML_UINT,  0, offsetof(MatroskaDemuxContext,time_scale), {.u=1000000} },
 301     { MATROSKA_ID_DURATION,           EBML_FLOAT, 0, offsetof(MatroskaDemuxContext,duration) },
 302     { MATROSKA_ID_TITLE,              EBML_UTF8,  0, offsetof(MatroskaDemuxContext,title) },
 303     { MATROSKA_ID_WRITINGAPP,         EBML_NONE },
 304     { MATROSKA_ID_MUXINGAPP,          EBML_NONE },
 305     { MATROSKA_ID_DATEUTC,            EBML_BIN,  0, offsetof(MatroskaDemuxContext,date_utc) },
 306     { MATROSKA_ID_SEGMENTUID,         EBML_NONE },
 307     { 0 }
 308 };
 309
 310 static EbmlSyntax matroska_track_video[] = {
 311     { MATROSKA_ID_VIDEOFRAMERATE,     EBML_FLOAT,0, offsetof(MatroskaTrackVideo,frame_rate) },
 312     { MATROSKA_ID_VIDEODISPLAYWIDTH,  EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_width) },
 313     { MATROSKA_ID_VIDEODISPLAYHEIGHT, EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_height) },
 314     { MATROSKA_ID_VIDEOPIXELWIDTH,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_width) },
 315     { MATROSKA_ID_VIDEOPIXELHEIGHT,   EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_height) },
 316     { MATROSKA_ID_VIDEOCOLORSPACE,    EBML_BIN,  0, offsetof(MatroskaTrackVideo,color_space) },
 317     { MATROSKA_ID_VIDEOSTEREOMODE,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,stereo_mode) },
 318     { MATROSKA_ID_VIDEOPIXELCROPB,    EBML_NONE },
 319     { MATROSKA_ID_VIDEOPIXELCROPT,    EBML_NONE },
 320     { MATROSKA_ID_VIDEOPIXELCROPL,    EBML_NONE },
 321     { MATROSKA_ID_VIDEOPIXELCROPR,    EBML_NONE },
 322     { MATROSKA_ID_VIDEODISPLAYUNIT,   EBML_NONE },
 323     { MATROSKA_ID_VIDEOFLAGINTERLACED,EBML_NONE },
 324     { MATROSKA_ID_VIDEOASPECTRATIO,   EBML_NONE },
 325     { 0 }
 326 };
 327
 328 static EbmlSyntax matroska_track_audio[] = {
 329     { MATROSKA_ID_AUDIOSAMPLINGFREQ,  EBML_FLOAT,0, offsetof(MatroskaTrackAudio,samplerate), {.f=8000.0} },
 330     { MATROSKA_ID_AUDIOOUTSAMPLINGFREQ,EBML_FLOAT,0,offsetof(MatroskaTrackAudio,out_samplerate) },
 331     { MATROSKA_ID_AUDIOBITDEPTH,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,bitdepth) },
 332     { MATROSKA_ID_AUDIOCHANNELS,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,channels), {.u=1} },
 333     { 0 }
 334 };
 335
 336 static EbmlSyntax matroska_track_encoding_compression[] = {
 337     { MATROSKA_ID_ENCODINGCOMPALGO,   EBML_UINT, 0, offsetof(MatroskaTrackCompression,algo), {.u=0} },
 338     { MATROSKA_ID_ENCODINGCOMPSETTINGS,EBML_BIN, 0, offsetof(MatroskaTrackCompression,settings) },
 339     { 0 }
 340 };
 341
 342 static EbmlSyntax matroska_track_encoding[] = {
 343     { MATROSKA_ID_ENCODINGSCOPE,      EBML_UINT, 0, offsetof(MatroskaTrackEncoding,scope), {.u=1} },
 344     { MATROSKA_ID_ENCODINGTYPE,       EBML_UINT, 0, offsetof(MatroskaTrackEncoding,type), {.u=0} },
 345     { MATROSKA_ID_ENCODINGCOMPRESSION,EBML_NEST, 0, offsetof(MatroskaTrackEncoding,compression), {.n=matroska_track_encoding_compression} },
 346     { MATROSKA_ID_ENCODINGORDER,      EBML_NONE },
 347     { 0 }
 348 };
 349
 350 static EbmlSyntax matroska_track_encodings[] = {
 351     { MATROSKA_ID_TRACKCONTENTENCODING, EBML_NEST, sizeof(MatroskaTrackEncoding), offsetof(MatroskaTrack,encodings), {.n=matroska_track_encoding} },
 352     { 0 }
 353 };
 354
 355 static EbmlSyntax matroska_track_plane[] = {
 356     { MATROSKA_ID_TRACKPLANEUID,  EBML_UINT, 0, offsetof(MatroskaTrackPlane,uid) },
 357     { MATROSKA_ID_TRACKPLANETYPE, EBML_UINT, 0, offsetof(MatroskaTrackPlane,type) },
 358     { 0 }
 359 };
 360
 361 static EbmlSyntax matroska_track_combine_planes[] = {
 362     { MATROSKA_ID_TRACKPLANE, EBML_NEST, sizeof(MatroskaTrackPlane), offsetof(MatroskaTrackOperation,combine_planes), {.n=matroska_track_plane} },
 363     { 0 }
 364 };
 365
 366 static EbmlSyntax matroska_track_operation[] = {
 367     { MATROSKA_ID_TRACKCOMBINEPLANES, EBML_NEST, 0, 0, {.n=matroska_track_combine_planes} },
 368     { 0 }
 369 };
 370
 371 static EbmlSyntax matroska_track[] = {
 372     { MATROSKA_ID_TRACKNUMBER,          EBML_UINT, 0, offsetof(MatroskaTrack,num) },
 373     { MATROSKA_ID_TRACKNAME,            EBML_UTF8, 0, offsetof(MatroskaTrack,name) },
 374     { MATROSKA_ID_TRACKUID,             EBML_UINT, 0, offsetof(MatroskaTrack,uid) },
 375     { MATROSKA_ID_TRACKTYPE,            EBML_UINT, 0, offsetof(MatroskaTrack,type) },
 376     { MATROSKA_ID_CODECID,              EBML_STR,  0, offsetof(MatroskaTrack,codec_id) },
 377     { MATROSKA_ID_CODECPRIVATE,         EBML_BIN,  0, offsetof(MatroskaTrack,codec_priv) },
 378     { MATROSKA_ID_TRACKLANGUAGE,        EBML_UTF8, 0, offsetof(MatroskaTrack,language), {.s="eng"} },
 379     { MATROSKA_ID_TRACKDEFAULTDURATION, EBML_UINT, 0, offsetof(MatroskaTrack,default_duration) },
 380     { MATROSKA_ID_TRACKTIMECODESCALE,   EBML_FLOAT,0, offsetof(MatroskaTrack,time_scale), {.f=1.0} },
 381     { MATROSKA_ID_TRACKFLAGDEFAULT,     EBML_UINT, 0, offsetof(MatroskaTrack,flag_default), {.u=1} },
 382     { MATROSKA_ID_TRACKFLAGFORCED,      EBML_UINT, 0, offsetof(MatroskaTrack,flag_forced), {.u=0} },
 383     { MATROSKA_ID_TRACKVIDEO,           EBML_NEST, 0, offsetof(MatroskaTrack,video), {.n=matroska_track_video} },
 384     { MATROSKA_ID_TRACKAUDIO,           EBML_NEST, 0, offsetof(MatroskaTrack,audio), {.n=matroska_track_audio} },
 385     { MATROSKA_ID_TRACKOPERATION,       EBML_NEST, 0, offsetof(MatroskaTrack,operation), {.n=matroska_track_operation} },
 386     { MATROSKA_ID_TRACKCONTENTENCODINGS,EBML_NEST, 0, 0, {.n=matroska_track_encodings} },
 387     { MATROSKA_ID_TRACKFLAGENABLED,     EBML_NONE },
 388     { MATROSKA_ID_TRACKFLAGLACING,      EBML_NONE },
 389     { MATROSKA_ID_CODECNAME,            EBML_NONE },
 390     { MATROSKA_ID_CODECDECODEALL,       EBML_NONE },
 391     { MATROSKA_ID_CODECINFOURL,         EBML_NONE },
 392     { MATROSKA_ID_CODECDOWNLOADURL,     EBML_NONE },
 393     { MATROSKA_ID_TRACKMINCACHE,        EBML_NONE },
 394     { MATROSKA_ID_TRACKMAXCACHE,        EBML_NONE },
 395     { MATROSKA_ID_TRACKMAXBLKADDID,     EBML_NONE },
 396     { 0 }
 397 };
 398
 399 static EbmlSyntax matroska_tracks[] = {
 400     { MATROSKA_ID_TRACKENTRY,         EBML_NEST, sizeof(MatroskaTrack), offsetof(MatroskaDemuxContext,tracks), {.n=matroska_track} },
 401     { 0 }
 402 };
 403
 404 static EbmlSyntax matroska_attachment[] = {
 405     { MATROSKA_ID_FILEUID,            EBML_UINT, 0, offsetof(MatroskaAttachement,uid) },
 406     { MATROSKA_ID_FILENAME,           EBML_UTF8, 0, offsetof(MatroskaAttachement,filename) },
 407     { MATROSKA_ID_FILEMIMETYPE,       EBML_STR,  0, offsetof(MatroskaAttachement,mime) },
 408     { MATROSKA_ID_FILEDATA,           EBML_BIN,  0, offsetof(MatroskaAttachement,bin) },
 409     { MATROSKA_ID_FILEDESC,           EBML_NONE },
 410     { 0 }
 411 };
 412
 413 static EbmlSyntax matroska_attachments[] = {
 414     { MATROSKA_ID_ATTACHEDFILE,       EBML_NEST, sizeof(MatroskaAttachement), offsetof(MatroskaDemuxContext,attachments), {.n=matroska_attachment} },
 415     { 0 }
 416 };
 417
 418 static EbmlSyntax matroska_chapter_display[] = {
 419     { MATROSKA_ID_CHAPSTRING,         EBML_UTF8, 0, offsetof(MatroskaChapter,title) },
 420     { MATROSKA_ID_CHAPLANG,           EBML_NONE },
 421     { 0 }
 422 };
 423
 424 static EbmlSyntax matroska_chapter_entry[] = {
 425     { MATROSKA_ID_CHAPTERTIMESTART,   EBML_UINT, 0, offsetof(MatroskaChapter,start), {.u=AV_NOPTS_VALUE} },
 426     { MATROSKA_ID_CHAPTERTIMEEND,     EBML_UINT, 0, offsetof(MatroskaChapter,end), {.u=AV_NOPTS_VALUE} },
 427     { MATROSKA_ID_CHAPTERUID,         EBML_UINT, 0, offsetof(MatroskaChapter,uid) },
 428     { MATROSKA_ID_CHAPTERDISPLAY,     EBML_NEST, 0, 0, {.n=matroska_chapter_display} },
 429     { MATROSKA_ID_CHAPTERFLAGHIDDEN,  EBML_NONE },
 430     { MATROSKA_ID_CHAPTERFLAGENABLED, EBML_NONE },
 431     { MATROSKA_ID_CHAPTERPHYSEQUIV,   EBML_NONE },
 432     { MATROSKA_ID_CHAPTERATOM,        EBML_NONE },
 433     { 0 }
 434 };
 435
 436 static EbmlSyntax matroska_chapter[] = {
 437     { MATROSKA_ID_CHAPTERATOM,        EBML_NEST, sizeof(MatroskaChapter), offsetof(MatroskaDemuxContext,chapters), {.n=matroska_chapter_entry} },
 438     { MATROSKA_ID_EDITIONUID,         EBML_NONE },
 439     { MATROSKA_ID_EDITIONFLAGHIDDEN,  EBML_NONE },
 440     { MATROSKA_ID_EDITIONFLAGDEFAULT, EBML_NONE },
 441     { MATROSKA_ID_EDITIONFLAGORDERED, EBML_NONE },
 442     { 0 }
 443 };
 444
 445 static EbmlSyntax matroska_chapters[] = {
 446     { MATROSKA_ID_EDITIONENTRY,       EBML_NEST, 0, 0, {.n=matroska_chapter} },
 447     { 0 }
 448 };
 449
 450 static EbmlSyntax matroska_index_pos[] = {
 451     { MATROSKA_ID_CUETRACK,           EBML_UINT, 0, offsetof(MatroskaIndexPos,track) },
 452     { MATROSKA_ID_CUECLUSTERPOSITION, EBML_UINT, 0, offsetof(MatroskaIndexPos,pos)   },
 453     { MATROSKA_ID_CUEBLOCKNUMBER,     EBML_NONE },
 454     { 0 }
 455 };
 456
 457 static EbmlSyntax matroska_index_entry[] = {
 458     { MATROSKA_ID_CUETIME,            EBML_UINT, 0, offsetof(MatroskaIndex,time) },
 459     { MATROSKA_ID_CUETRACKPOSITION,   EBML_NEST, sizeof(MatroskaIndexPos), offsetof(MatroskaIndex,pos), {.n=matroska_index_pos} },
 460     { 0 }
 461 };
 462
 463 static EbmlSyntax matroska_index[] = {
 464     { MATROSKA_ID_POINTENTRY,         EBML_NEST, sizeof(MatroskaIndex), offsetof(MatroskaDemuxContext,index), {.n=matroska_index_entry} },
 465     { 0 }
 466 };
 467
 468 static EbmlSyntax matroska_simpletag[] = {
 469     { MATROSKA_ID_TAGNAME,            EBML_UTF8, 0, offsetof(MatroskaTag,name) },
 470     { MATROSKA_ID_TAGSTRING,          EBML_UTF8, 0, offsetof(MatroskaTag,string) },
 471     { MATROSKA_ID_TAGLANG,            EBML_STR,  0, offsetof(MatroskaTag,lang), {.s="und"} },
 472     { MATROSKA_ID_TAGDEFAULT,         EBML_UINT, 0, offsetof(MatroskaTag,def) },
 473     { MATROSKA_ID_TAGDEFAULT_BUG,     EBML_UINT, 0, offsetof(MatroskaTag,def) },
 474     { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTag,sub), {.n=matroska_simpletag} },
 475     { 0 }
 476 };
 477
 478 static EbmlSyntax matroska_tagtargets[] = {
 479     { MATROSKA_ID_TAGTARGETS_TYPE,      EBML_STR,  0, offsetof(MatroskaTagTarget,type) },
 480     { MATROSKA_ID_TAGTARGETS_TYPEVALUE, EBML_UINT, 0, offsetof(MatroskaTagTarget,typevalue), {.u=50} },
 481     { MATROSKA_ID_TAGTARGETS_TRACKUID,  EBML_UINT, 0, offsetof(MatroskaTagTarget,trackuid) },
 482     { MATROSKA_ID_TAGTARGETS_CHAPTERUID,EBML_UINT, 0, offsetof(MatroskaTagTarget,chapteruid) },
 483     { MATROSKA_ID_TAGTARGETS_ATTACHUID, EBML_UINT, 0, offsetof(MatroskaTagTarget,attachuid) },
 484     { 0 }
 485 };
 486
 487 static EbmlSyntax matroska_tag[] = {
 488     { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTags,tag), {.n=matroska_simpletag} },
 489     { MATROSKA_ID_TAGTARGETS,         EBML_NEST, 0, offsetof(MatroskaTags,target), {.n=matroska_tagtargets} },
 490     { 0 }
 491 };
 492
 493 static EbmlSyntax matroska_tags[] = {
 494     { MATROSKA_ID_TAG,                EBML_NEST, sizeof(MatroskaTags), offsetof(MatroskaDemuxContext,tags), {.n=matroska_tag} },
 495     { 0 }
 496 };
 497
 498 static EbmlSyntax matroska_seekhead_entry[] = {
 499     { MATROSKA_ID_SEEKID,             EBML_UINT, 0, offsetof(MatroskaSeekhead,id) },
 500     { MATROSKA_ID_SEEKPOSITION,       EBML_UINT, 0, offsetof(MatroskaSeekhead,pos), {.u=-1} },
 501     { 0 }
 502 };
 503
 504 static EbmlSyntax matroska_seekhead[] = {
 505     { MATROSKA_ID_SEEKENTRY,          EBML_NEST, sizeof(MatroskaSeekhead), offsetof(MatroskaDemuxContext,seekhead), {.n=matroska_seekhead_entry} },
 506     { 0 }
 507 };
 508
 509 static EbmlSyntax matroska_segment[] = {
 510     { MATROSKA_ID_INFO,           EBML_NEST, 0, 0, {.n=matroska_info       } },
 511     { MATROSKA_ID_TRACKS,         EBML_NEST, 0, 0, {.n=matroska_tracks     } },
 512     { MATROSKA_ID_ATTACHMENTS,    EBML_NEST, 0, 0, {.n=matroska_attachments} },
 513     { MATROSKA_ID_CHAPTERS,       EBML_NEST, 0, 0, {.n=matroska_chapters   } },
 514     { MATROSKA_ID_CUES,           EBML_NEST, 0, 0, {.n=matroska_index      } },
 515     { MATROSKA_ID_TAGS,           EBML_NEST, 0, 0, {.n=matroska_tags       } },
 516     { MATROSKA_ID_SEEKHEAD,       EBML_NEST, 0, 0, {.n=matroska_seekhead   } },
 517     { MATROSKA_ID_CLUSTER,        EBML_STOP },
 518     { 0 }
 519 };
 520
 521 static EbmlSyntax matroska_segments[] = {
 522     { MATROSKA_ID_SEGMENT,        EBML_NEST, 0, 0, {.n=matroska_segment    } },
 523     { 0 }
 524 };
 525
 526 static EbmlSyntax matroska_blockgroup[] = {
 527     { MATROSKA_ID_BLOCK,          EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
 528     { MATROSKA_ID_SIMPLEBLOCK,    EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
 529     { MATROSKA_ID_BLOCKDURATION,  EBML_UINT, 0, offsetof(MatroskaBlock,duration) },
 530     { MATROSKA_ID_BLOCKREFERENCE, EBML_UINT, 0, offsetof(MatroskaBlock,reference) },
 531     { 1,                          EBML_UINT, 0, offsetof(MatroskaBlock,non_simple), {.u=1} },
 532     { 0 }
 533 };
 534
 535 static EbmlSyntax matroska_cluster[] = {
 536     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
 537     { MATROSKA_ID_BLOCKGROUP,     EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 538     { MATROSKA_ID_SIMPLEBLOCK,    EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 539     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
 540     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
 541     { 0 }
 542 };
 543
 544 static EbmlSyntax matroska_clusters[] = {
 545     { MATROSKA_ID_CLUSTER,        EBML_NEST, 0, 0, {.n=matroska_cluster} },
 546     { MATROSKA_ID_INFO,           EBML_NONE },
 547     { MATROSKA_ID_CUES,           EBML_NONE },
 548     { MATROSKA_ID_TAGS,           EBML_NONE },
 549     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
 550     { 0 }
 551 };
 552
 553 static EbmlSyntax matroska_cluster_incremental_parsing[] = {
 554     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
 555     { MATROSKA_ID_BLOCKGROUP,     EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 556     { MATROSKA_ID_SIMPLEBLOCK,    EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 557     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
 558     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
 559     { MATROSKA_ID_INFO,           EBML_NONE },
 560     { MATROSKA_ID_CUES,           EBML_NONE },
 561     { MATROSKA_ID_TAGS,           EBML_NONE },
 562     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
 563     { MATROSKA_ID_CLUSTER,        EBML_STOP },
 564     { 0 }
 565 };
 566
 567 static EbmlSyntax matroska_cluster_incremental[] = {
 568     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
 569     { MATROSKA_ID_BLOCKGROUP,     EBML_STOP },
 570     { MATROSKA_ID_SIMPLEBLOCK,    EBML_STOP },
 571     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
 572     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
 573     { 0 }
 574 };
 575
 576 static EbmlSyntax matroska_clusters_incremental[] = {
 577     { MATROSKA_ID_CLUSTER,        EBML_NEST, 0, 0, {.n=matroska_cluster_incremental} },
 578     { MATROSKA_ID_INFO,           EBML_NONE },
 579     { MATROSKA_ID_CUES,           EBML_NONE },
 580     { MATROSKA_ID_TAGS,           EBML_NONE },
 581     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
 582     { 0 }
 583 };
 584
 585 static const char *const matroska_doctypes[] = { "matroska", "webm" };
 586
 587 static int matroska_resync(MatroskaDemuxContext *matroska, int64_t last_pos)
 588 {
 589     AVIOContext *pb = matroska->ctx->pb;
 590     uint32_t id;
 591     matroska->current_id = 0;
 592     matroska->num_levels = 0;
 593
 594     // seek to next position to resync from
 595     if (avio_seek(pb, last_pos + 1, SEEK_SET) < 0 || avio_tell(pb) <= last_pos)
 596         goto eof;
 597
 598     id = avio_rb32(pb);
 599
 600     // try to find a toplevel element
 601     while (!url_feof(pb)) {
 602         if (id == MATROSKA_ID_INFO || id == MATROSKA_ID_TRACKS ||
 603             id == MATROSKA_ID_CUES || id == MATROSKA_ID_TAGS ||
 604             id == MATROSKA_ID_SEEKHEAD || id == MATROSKA_ID_ATTACHMENTS ||
 605             id == MATROSKA_ID_CLUSTER || id == MATROSKA_ID_CHAPTERS)
 606         {
 607             matroska->current_id = id;
 608             return 0;
 609         }
 610         id = (id << 8) | avio_r8(pb);
 611     }
 612 eof:
 613     matroska->done = 1;
 614     return AVERROR_EOF;
 615 }
 616
 617 /*
 618  * Return: Whether we reached the end of a level in the hierarchy or not.
 619  */
 620 static int ebml_level_end(MatroskaDemuxContext *matroska)
 621 {
 622     AVIOContext *pb = matroska->ctx->pb;
 623     int64_t pos = avio_tell(pb);
 624
 625     if (matroska->num_levels > 0) {
 626         MatroskaLevel *level = &matroska->levels[matroska->num_levels - 1];
 627         if (pos - level->start >= level->length || matroska->current_id) {
 628             matroska->num_levels--;
 629             return 1;
 630         }
 631     }
 632     return 0;
 633 }
 634
 635 /*
 636  * Read: an "EBML number", which is defined as a variable-length
 637  * array of bytes. The first byte indicates the length by giving a
 638  * number of 0-bits followed by a one. The position of the first
 639  * "one" bit inside the first byte indicates the length of this
 640  * number.
 641  * Returns: number of bytes read, < 0 on error
 642  */
 643 static int ebml_read_num(MatroskaDemuxContext *matroska, AVIOContext *pb,
 644                          int max_size, uint64_t *number)
 645 {
 646     int read = 1, n = 1;
 647     uint64_t total = 0;
 648
 649     /* The first byte tells us the length in bytes - avio_r8() can normally
 650      * return 0, but since that's not a valid first ebmlID byte, we can
 651      * use it safely here to catch EOS. */
 652     if (!(total = avio_r8(pb))) {
 653         /* we might encounter EOS here */
 654         if (!url_feof(pb)) {
 655             int64_t pos = avio_tell(pb);
 656             av_log(matroska->ctx, AV_LOG_ERROR,
 657                    "Read error at pos. %"PRIu64" (0x%"PRIx64")\n",
 658                    pos, pos);
 659             return pb->error ? pb->error : AVERROR(EIO);
 660         }
 661         return AVERROR_EOF;
 662     }
 663
 664     /* get the length of the EBML number */
 665     read = 8 - ff_log2_tab[total];
 666     if (read > max_size) {
 667         int64_t pos = avio_tell(pb) - 1;
 668         av_log(matroska->ctx, AV_LOG_ERROR,
 669                "Invalid EBML number size tag 0x%02x at pos %"PRIu64" (0x%"PRIx64")\n",
 670                (uint8_t) total, pos, pos);
 671         return AVERROR_INVALIDDATA;
 672     }
 673
 674     /* read out length */
 675     total ^= 1 << ff_log2_tab[total];
 676     while (n++ < read)
 677         total = (total << 8) | avio_r8(pb);
 678
 679     *number = total;
 680
 681     return read;
 682 }
 683
 684 /**
 685  * Read a EBML length value.
 686  * This needs special handling for the "unknown length" case which has multiple
 687  * encodings.
 688  */
 689 static int ebml_read_length(MatroskaDemuxContext *matroska, AVIOContext *pb,
 690                             uint64_t *number)
 691 {
 692     int res = ebml_read_num(matroska, pb, 8, number);
 693     if (res > 0 && *number + 1 == 1ULL << (7 * res))
 694         *number = 0xffffffffffffffULL;
 695     return res;
 696 }
 697
 698 /*
 699  * Read the next element as an unsigned int.
 700  * 0 is success, < 0 is failure.
 701  */
 702 static int ebml_read_uint(AVIOContext *pb, int size, uint64_t *num)
 703 {
 704     int n = 0;
 705
 706     if (size > 8)
 707         return AVERROR_INVALIDDATA;
 708
 709     /* big-endian ordering; build up number */
 710     *num = 0;
 711     while (n++ < size)
 712         *num = (*num << 8) | avio_r8(pb);
 713
 714     return 0;
 715 }
 716
 717 /*
 718  * Read the next element as a float.
 719  * 0 is success, < 0 is failure.
 720  */
 721 static int ebml_read_float(AVIOContext *pb, int size, double *num)
 722 {
 723     if (size == 0) {
 724         *num = 0;
 725     } else if (size == 4) {
 726         *num = av_int2float(avio_rb32(pb));
 727     } else if (size == 8){
 728         *num = av_int2double(avio_rb64(pb));
 729     } else
 730         return AVERROR_INVALIDDATA;
 731
 732     return 0;
 733 }
 734
 735 /*
 736  * Read the next element as an ASCII string.
 737  * 0 is success, < 0 is failure.
 738  */
 739 static int ebml_read_ascii(AVIOContext *pb, int size, char **str)
 740 {
 741     char *res;
 742
 743     /* EBML strings are usually not 0-terminated, so we allocate one
 744      * byte more, read the string and NULL-terminate it ourselves. */
 745     if (!(res = av_malloc(size + 1)))
 746         return AVERROR(ENOMEM);
 747     if (avio_read(pb, (uint8_t *) res, size) != size) {
 748         av_free(res);
 749         return AVERROR(EIO);
 750     }
 751     (res)[size] = '\0';
 752     av_free(*str);
 753     *str = res;
 754
 755     return 0;
 756 }
 757
 758 /*
 759  * Read the next element as binary data.
 760  * 0 is success, < 0 is failure.
 761  */
 762 static int ebml_read_binary(AVIOContext *pb, int length, EbmlBin *bin)
 763 {
 764     av_free(bin->data);
 765     if (!(bin->data = av_malloc(length)))
 766         return AVERROR(ENOMEM);
 767
 768     bin->size = length;
 769     bin->pos  = avio_tell(pb);
 770     if (avio_read(pb, bin->data, length) != length) {
 771         av_freep(&bin->data);
 772         return AVERROR(EIO);
 773     }
 774
 775     return 0;
 776 }
 777
 778 /*
 779  * Read the next element, but only the header. The contents
 780  * are supposed to be sub-elements which can be read separately.
 781  * 0 is success, < 0 is failure.
 782  */
 783 static int ebml_read_master(MatroskaDemuxContext *matroska, uint64_t length)
 784 {
 785     AVIOContext *pb = matroska->ctx->pb;
 786     MatroskaLevel *level;
 787
 788     if (matroska->num_levels >= EBML_MAX_DEPTH) {
 789         av_log(matroska->ctx, AV_LOG_ERROR,
 790                "File moves beyond max. allowed depth (%d)\n", EBML_MAX_DEPTH);
 791         return AVERROR(ENOSYS);
 792     }
 793
 794     level = &matroska->levels[matroska->num_levels++];
 795     level->start = avio_tell(pb);
 796     level->length = length;
 797
 798     return 0;
 799 }
 800
 801 /*
 802  * Read signed/unsigned "EBML" numbers.
 803  * Return: number of bytes processed, < 0 on error
 804  */
 805 static int matroska_ebmlnum_uint(MatroskaDemuxContext *matroska,
 806                                  uint8_t *data, uint32_t size, uint64_t *num)
 807 {
 808     AVIOContext pb;
 809     ffio_init_context(&pb, data, size, 0, NULL, NULL, NULL, NULL);
 810     return ebml_read_num(matroska, &pb, FFMIN(size, 8), num);
 811 }
 812
 813 /*
 814  * Same as above, but signed.
 815  */
 816 static int matroska_ebmlnum_sint(MatroskaDemuxContext *matroska,
 817                                  uint8_t *data, uint32_t size, int64_t *num)
 818 {
 819     uint64_t unum;
 820     int res;
 821
 822     /* read as unsigned number first */
 823     if ((res = matroska_ebmlnum_uint(matroska, data, size, &unum)) < 0)
 824         return res;
 825
 826     /* make signed (weird way) */
 827     *num = unum - ((1LL << (7*res - 1)) - 1);
 828
 829     return res;
 830 }
 831
 832 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
 833                            EbmlSyntax *syntax, void *data);
 834
 835 static int ebml_parse_id(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 836                          uint32_t id, void *data)
 837 {
 838     int i;
 839     for (i=0; syntax[i].id; i++)
 840         if (id == syntax[i].id)
 841             break;
 842     if (!syntax[i].id && id == MATROSKA_ID_CLUSTER &&
 843         matroska->num_levels > 0 &&
 844         matroska->levels[matroska->num_levels-1].length == 0xffffffffffffff)
 845         return 0;  // we reached the end of an unknown size cluster
 846     if (!syntax[i].id && id != EBML_ID_VOID && id != EBML_ID_CRC32) {
 847         av_log(matroska->ctx, AV_LOG_INFO, "Unknown entry 0x%X\n", id);
 848         if (matroska->ctx->error_recognition & AV_EF_EXPLODE)
 849             return AVERROR_INVALIDDATA;
 850     }
 851     return ebml_parse_elem(matroska, &syntax[i], data);
 852 }
 853
 854 static int ebml_parse(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 855                       void *data)
 856 {
 857     if (!matroska->current_id) {
 858         uint64_t id;
 859         int res = ebml_read_num(matroska, matroska->ctx->pb, 4, &id);
 860         if (res < 0)
 861             return res;
 862         matroska->current_id = id | 1 << 7*res;
 863     }
 864     return ebml_parse_id(matroska, syntax, matroska->current_id, data);
 865 }
 866
 867 static int ebml_parse_nest(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 868                            void *data)
 869 {
 870     int i, res = 0;
 871
 872     for (i=0; syntax[i].id; i++)
 873         switch (syntax[i].type) {
 874         case EBML_UINT:
 875             *(uint64_t *)((char *)data+syntax[i].data_offset) = syntax[i].def.u;
 876             break;
 877         case EBML_FLOAT:
 878             *(double   *)((char *)data+syntax[i].data_offset) = syntax[i].def.f;
 879             break;
 880         case EBML_STR:
 881         case EBML_UTF8:
 882             *(char    **)((char *)data+syntax[i].data_offset) = av_strdup(syntax[i].def.s);
 883             break;
 884         }
 885
 886     while (!res && !ebml_level_end(matroska))
 887         res = ebml_parse(matroska, syntax, data);
 888
 889     return res;
 890 }
 891
 892 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
 893                            EbmlSyntax *syntax, void *data)
 894 {
 895     static const uint64_t max_lengths[EBML_TYPE_COUNT] = {
 896         [EBML_UINT]  = 8,
 897         [EBML_FLOAT] = 8,
 898         // max. 16 MB for strings
 899         [EBML_STR]   = 0x1000000,
 900         [EBML_UTF8]  = 0x1000000,
 901         // max. 256 MB for binary data
 902         [EBML_BIN]   = 0x10000000,
 903         // no limits for anything else
 904     };
 905     AVIOContext *pb = matroska->ctx->pb;
 906     uint32_t id = syntax->id;
 907     uint64_t length;
 908     int res;
 909     void *newelem;
 910
 911     data = (char *)data + syntax->data_offset;
 912     if (syntax->list_elem_size) {
 913         EbmlList *list = data;
 914         newelem = av_realloc(list->elem, (list->nb_elem+1)*syntax->list_elem_size);
 915         if (!newelem)
 916             return AVERROR(ENOMEM);
 917         list->elem = newelem;
 918         data = (char*)list->elem + list->nb_elem*syntax->list_elem_size;
 919         memset(data, 0, syntax->list_elem_size);
 920         list->nb_elem++;
 921     }
 922
 923     if (syntax->type != EBML_PASS && syntax->type != EBML_STOP) {
 924         matroska->current_id = 0;
 925         if ((res = ebml_read_length(matroska, pb, &length)) < 0)
 926             return res;
 927         if (max_lengths[syntax->type] && length > max_lengths[syntax->type]) {
 928             av_log(matroska->ctx, AV_LOG_ERROR,
 929                    "Invalid length 0x%"PRIx64" > 0x%"PRIx64" for syntax element %i\n",
 930                    length, max_lengths[syntax->type], syntax->type);
 931             return AVERROR_INVALIDDATA;
 932         }
 933     }
 934
 935     switch (syntax->type) {
 936     case EBML_UINT:  res = ebml_read_uint  (pb, length, data);  break;
 937     case EBML_FLOAT: res = ebml_read_float (pb, length, data);  break;
 938     case EBML_STR:
 939     case EBML_UTF8:  res = ebml_read_ascii (pb, length, data);  break;
 940     case EBML_BIN:   res = ebml_read_binary(pb, length, data);  break;
 941     case EBML_NEST:  if ((res=ebml_read_master(matroska, length)) < 0)
 942                          return res;
 943                      if (id == MATROSKA_ID_SEGMENT)
 944                          matroska->segment_start = avio_tell(matroska->ctx->pb);
 945                      return ebml_parse_nest(matroska, syntax->def.n, data);
 946     case EBML_PASS:  return ebml_parse_id(matroska, syntax->def.n, id, data);
 947     case EBML_STOP:  return 1;
 948     default:
 949         if(ffio_limit(pb, length) != length)
 950             return AVERROR(EIO);
 951         return avio_skip(pb,length)<0 ? AVERROR(EIO) : 0;
 952     }
 953     if (res == AVERROR_INVALIDDATA)
 954         av_log(matroska->ctx, AV_LOG_ERROR, "Invalid element\n");
 955     else if (res == AVERROR(EIO))
 956         av_log(matroska->ctx, AV_LOG_ERROR, "Read error\n");
 957     return res;
 958 }
 959
 960 static void ebml_free(EbmlSyntax *syntax, void *data)
 961 {
 962     int i, j;
 963     for (i=0; syntax[i].id; i++) {
 964         void *data_off = (char *)data + syntax[i].data_offset;
 965         switch (syntax[i].type) {
 966         case EBML_STR:
 967         case EBML_UTF8:  av_freep(data_off);                      break;
 968         case EBML_BIN:   av_freep(&((EbmlBin *)data_off)->data);  break;
 969         case EBML_NEST:
 970             if (syntax[i].list_elem_size) {
 971                 EbmlList *list = data_off;
 972                 char *ptr = list->elem;
 973                 for (j=0; j<list->nb_elem; j++, ptr+=syntax[i].list_elem_size)
 974                     ebml_free(syntax[i].def.n, ptr);
 975                 av_free(list->elem);
 976             } else
 977                 ebml_free(syntax[i].def.n, data_off);
 978         default:  break;
 979         }
 980     }
 981 }
 982
 983
 984 /*
 985  * Autodetecting...
 986  */
 987 static int matroska_probe(AVProbeData *p)
 988 {
 989     uint64_t total = 0;
 990     int len_mask = 0x80, size = 1, n = 1, i;
 991
 992     /* EBML header? */
 993     if (AV_RB32(p->buf) != EBML_ID_HEADER)
 994         return 0;
 995
 996     /* length of header */
 997     total = p->buf[4];
 998     while (size <= 8 && !(total & len_mask)) {
 999         size++;
1000         len_mask >>= 1;
1001     }
1002     if (size > 8)
1003       return 0;
1004     total &= (len_mask - 1);
1005     while (n < size)
1006         total = (total << 8) | p->buf[4 + n++];
1007
1008     /* Does the probe data contain the whole header? */
1009     if (p->buf_size < 4 + size + total)
1010       return 0;
1011
1012     /* The header should contain a known document type. For now,
1013      * we don't parse the whole header but simply check for the
1014      * availability of that array of characters inside the header.
1015      * Not fully fool-proof, but good enough. */
1016     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++) {
1017         int probelen = strlen(matroska_doctypes[i]);
1018         if (total < probelen)
1019             continue;
1020         for (n = 4+size; n <= 4+size+total-probelen; n++)
1021             if (!memcmp(p->buf+n, matroska_doctypes[i], probelen))
1022                 return AVPROBE_SCORE_MAX;
1023     }
1024
1025     // probably valid EBML header but no recognized doctype
1026     return AVPROBE_SCORE_MAX/2;
1027 }
1028
1029 static MatroskaTrack *matroska_find_track_by_num(MatroskaDemuxContext *matroska,
1030                                                  int num)
1031 {
1032     MatroskaTrack *tracks = matroska->tracks.elem;
1033     int i;
1034
1035     for (i=0; i < matroska->tracks.nb_elem; i++)
1036         if (tracks[i].num == num)
1037             return &tracks[i];
1038
1039     av_log(matroska->ctx, AV_LOG_ERROR, "Invalid track number %d\n", num);
1040     return NULL;
1041 }
1042
1043 static int matroska_decode_buffer(uint8_t** buf, int* buf_size,
1044                                   MatroskaTrack *track)
1045 {
1046     MatroskaTrackEncoding *encodings = track->encodings.elem;
1047     uint8_t* data = *buf;
1048     int isize = *buf_size;
1049     uint8_t* pkt_data = NULL;
1050     uint8_t av_unused *newpktdata;
1051     int pkt_size = isize;
1052     int result = 0;
1053     int olen;
1054
1055     if (pkt_size >= 10000000U)
1056         return -1;
1057
1058     switch (encodings[0].compression.algo) {
1059     case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP:
1060         if (encodings[0].compression.settings.size && !encodings[0].compression.settings.data) {
1061             av_log(0, AV_LOG_ERROR, "Compression size but no data in headerstrip\n");
1062             return -1;
1063         }
1064         return encodings[0].compression.settings.size;
1065     case MATROSKA_TRACK_ENCODING_COMP_LZO:
1066         do {
1067             olen = pkt_size *= 3;
1068             pkt_data = av_realloc(pkt_data, pkt_size+AV_LZO_OUTPUT_PADDING);
1069             result = av_lzo1x_decode(pkt_data, &olen, data, &isize);
1070         } while (result==AV_LZO_OUTPUT_FULL && pkt_size<10000000);
1071         if (result)
1072             goto failed;
1073         pkt_size -= olen;
1074         break;
1075 #if CONFIG_ZLIB
1076     case MATROSKA_TRACK_ENCODING_COMP_ZLIB: {
1077         z_stream zstream = {0};
1078         if (inflateInit(&zstream) != Z_OK)
1079             return -1;
1080         zstream.next_in = data;
1081         zstream.avail_in = isize;
1082         do {
1083             pkt_size *= 3;
1084             newpktdata = av_realloc(pkt_data, pkt_size);
1085             if (!newpktdata) {
1086                 inflateEnd(&zstream);
1087                 goto failed;
1088             }
1089             pkt_data = newpktdata;
1090             zstream.avail_out = pkt_size - zstream.total_out;
1091             zstream.next_out = pkt_data + zstream.total_out;
1092             if (pkt_data) {
1093                 result = inflate(&zstream, Z_NO_FLUSH);
1094             } else
1095                 result = Z_MEM_ERROR;
1096         } while (result==Z_OK && pkt_size<10000000);
1097         pkt_size = zstream.total_out;
1098         inflateEnd(&zstream);
1099         if (result != Z_STREAM_END)
1100             goto failed;
1101         break;
1102     }
1103 #endif
1104 #if CONFIG_BZLIB
1105     case MATROSKA_TRACK_ENCODING_COMP_BZLIB: {
1106         bz_stream bzstream = {0};
1107         if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
1108             return -1;
1109         bzstream.next_in = data;
1110         bzstream.avail_in = isize;
1111         do {
1112             pkt_size *= 3;
1113             newpktdata = av_realloc(pkt_data, pkt_size);
1114             if (!newpktdata) {
1115                 BZ2_bzDecompressEnd(&bzstream);
1116                 goto failed;
1117             }
1118             pkt_data = newpktdata;
1119             bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
1120             bzstream.next_out = pkt_data + bzstream.total_out_lo32;
1121             if (pkt_data) {
1122                 result = BZ2_bzDecompress(&bzstream);
1123             } else
1124                 result = BZ_MEM_ERROR;
1125         } while (result==BZ_OK && pkt_size<10000000);
1126         pkt_size = bzstream.total_out_lo32;
1127         BZ2_bzDecompressEnd(&bzstream);
1128         if (result != BZ_STREAM_END)
1129             goto failed;
1130         break;
1131     }
1132 #endif
1133     default:
1134         return -1;
1135     }
1136
1137     *buf = pkt_data;
1138     *buf_size = pkt_size;
1139     return 0;
1140  failed:
1141     av_free(pkt_data);
1142     return -1;
1143 }
1144
1145 static void matroska_fix_ass_packet(MatroskaDemuxContext *matroska,
1146                                     AVPacket *pkt, uint64_t display_duration)
1147 {
1148     char *line, *layer, *ptr = pkt->data, *end = ptr+pkt->size;
1149     for (; *ptr!=',' && ptr<end-1; ptr++);
1150     if (*ptr == ',')
1151         ptr++;
1152     layer = ptr;
1153     for (; *ptr!=',' && ptr<end-1; ptr++);
1154     if (*ptr == ',') {
1155         int64_t end_pts = pkt->pts + display_duration;
1156         int sc = matroska->time_scale * pkt->pts / 10000000;
1157         int ec = matroska->time_scale * end_pts  / 10000000;
1158         int sh, sm, ss, eh, em, es, len;
1159         sh = sc/360000;  sc -= 360000*sh;
1160         sm = sc/  6000;  sc -=   6000*sm;
1161         ss = sc/   100;  sc -=    100*ss;
1162         eh = ec/360000;  ec -= 360000*eh;
1163         em = ec/  6000;  ec -=   6000*em;
1164         es = ec/   100;  ec -=    100*es;
1165         *ptr++ = '\0';
1166         len = 50 + end-ptr + FF_INPUT_BUFFER_PADDING_SIZE;
1167         if (!(line = av_malloc(len)))
1168             return;
1169         snprintf(line,len,"Dialogue: %s,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s\r\n",
1170                  layer, sh, sm, ss, sc, eh, em, es, ec, ptr);
1171         av_free(pkt->data);
1172         pkt->data = line;
1173         pkt->size = strlen(line);
1174     }
1175 }
1176
1177 static int matroska_merge_packets(AVPacket *out, AVPacket *in)
1178 {
1179     int ret = av_grow_packet(out, in->size);
1180     if (ret < 0)
1181         return ret;
1182     memcpy(out->data + out->size - in->size, in->data, in->size);
1183     av_destruct_packet(in);
1184     av_free(in);
1185     return 0;
1186 }
1187
1188 static void matroska_convert_tag(AVFormatContext *s, EbmlList *list,
1189                                  AVDictionary **metadata, char *prefix)
1190 {
1191     MatroskaTag *tags = list->elem;
1192     char key[1024];
1193     int i;
1194
1195     for (i=0; i < list->nb_elem; i++) {
1196         const char *lang= (tags[i].lang && strcmp(tags[i].lang, "und")) ? tags[i].lang : NULL;
1197
1198         if (!tags[i].name) {
1199             av_log(s, AV_LOG_WARNING, "Skipping invalid tag with no TagName.\n");
1200             continue;
1201         }
1202         if (prefix)  snprintf(key, sizeof(key), "%s/%s", prefix, tags[i].name);
1203         else         av_strlcpy(key, tags[i].name, sizeof(key));
1204         if (tags[i].def || !lang) {
1205         av_dict_set(metadata, key, tags[i].string, 0);
1206         if (tags[i].sub.nb_elem)
1207             matroska_convert_tag(s, &tags[i].sub, metadata, key);
1208         }
1209         if (lang) {
1210             av_strlcat(key, "-", sizeof(key));
1211             av_strlcat(key, lang, sizeof(key));
1212             av_dict_set(metadata, key, tags[i].string, 0);
1213             if (tags[i].sub.nb_elem)
1214                 matroska_convert_tag(s, &tags[i].sub, metadata, key);
1215         }
1216     }
1217     ff_metadata_conv(metadata, NULL, ff_mkv_metadata_conv);
1218 }
1219
1220 static void matroska_convert_tags(AVFormatContext *s)
1221 {
1222     MatroskaDemuxContext *matroska = s->priv_data;
1223     MatroskaTags *tags = matroska->tags.elem;
1224     int i, j;
1225
1226     for (i=0; i < matroska->tags.nb_elem; i++) {
1227         if (tags[i].target.attachuid) {
1228             MatroskaAttachement *attachment = matroska->attachments.elem;
1229             for (j=0; j<matroska->attachments.nb_elem; j++)
1230                 if (attachment[j].uid == tags[i].target.attachuid
1231                     && attachment[j].stream)
1232                     matroska_convert_tag(s, &tags[i].tag,
1233                                          &attachment[j].stream->metadata, NULL);
1234         } else if (tags[i].target.chapteruid) {
1235             MatroskaChapter *chapter = matroska->chapters.elem;
1236             for (j=0; j<matroska->chapters.nb_elem; j++)
1237                 if (chapter[j].uid == tags[i].target.chapteruid
1238                     && chapter[j].chapter)
1239                     matroska_convert_tag(s, &tags[i].tag,
1240                                          &chapter[j].chapter->metadata, NULL);
1241         } else if (tags[i].target.trackuid) {
1242             MatroskaTrack *track = matroska->tracks.elem;
1243             for (j=0; j<matroska->tracks.nb_elem; j++)
1244                 if (track[j].uid == tags[i].target.trackuid && track[j].stream)
1245                     matroska_convert_tag(s, &tags[i].tag,
1246                                          &track[j].stream->metadata, NULL);
1247         } else {
1248             matroska_convert_tag(s, &tags[i].tag, &s->metadata,
1249                                  tags[i].target.type);
1250         }
1251     }
1252 }
1253
1254 static int matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska, int idx)
1255 {
1256     EbmlList *seekhead_list = &matroska->seekhead;
1257     MatroskaSeekhead *seekhead = seekhead_list->elem;
1258     uint32_t level_up = matroska->level_up;
1259     int64_t before_pos = avio_tell(matroska->ctx->pb);
1260     uint32_t saved_id = matroska->current_id;
1261     MatroskaLevel level;
1262     int64_t offset;
1263     int ret = 0;
1264
1265     if (idx >= seekhead_list->nb_elem
1266             || seekhead[idx].id == MATROSKA_ID_SEEKHEAD
1267             || seekhead[idx].id == MATROSKA_ID_CLUSTER)
1268         return 0;
1269
1270     /* seek */
1271     offset = seekhead[idx].pos + matroska->segment_start;
1272     if (avio_seek(matroska->ctx->pb, offset, SEEK_SET) == offset) {
1273         /* We don't want to lose our seekhead level, so we add
1274          * a dummy. This is a crude hack. */
1275         if (matroska->num_levels == EBML_MAX_DEPTH) {
1276             av_log(matroska->ctx, AV_LOG_INFO,
1277                    "Max EBML element depth (%d) reached, "
1278                    "cannot parse further.\n", EBML_MAX_DEPTH);
1279             ret = AVERROR_INVALIDDATA;
1280         } else {
1281             level.start = 0;
1282             level.length = (uint64_t)-1;
1283             matroska->levels[matroska->num_levels] = level;
1284             matroska->num_levels++;
1285             matroska->current_id = 0;
1286
1287             ret = ebml_parse(matroska, matroska_segment, matroska);
1288
1289             /* remove dummy level */
1290             while (matroska->num_levels) {
1291                 uint64_t length = matroska->levels[--matroska->num_levels].length;
1292                 if (length == (uint64_t)-1)
1293                     break;
1294             }
1295         }
1296     }
1297     /* seek back */
1298     avio_seek(matroska->ctx->pb, before_pos, SEEK_SET);
1299     matroska->level_up = level_up;
1300     matroska->current_id = saved_id;
1301
1302     return ret;
1303 }
1304
1305 static void matroska_execute_seekhead(MatroskaDemuxContext *matroska)
1306 {
1307     EbmlList *seekhead_list = &matroska->seekhead;
1308     int64_t before_pos = avio_tell(matroska->ctx->pb);
1309     int i;
1310
1311     // we should not do any seeking in the streaming case
1312     if (!matroska->ctx->pb->seekable ||
1313         (matroska->ctx->flags & AVFMT_FLAG_IGNIDX))
1314         return;
1315
1316     for (i = 0; i < seekhead_list->nb_elem; i++) {
1317         MatroskaSeekhead *seekhead = seekhead_list->elem;
1318         if (seekhead[i].pos <= before_pos)
1319             continue;
1320
1321         // defer cues parsing until we actually need cue data.
1322         if (seekhead[i].id == MATROSKA_ID_CUES) {
1323             matroska->cues_parsing_deferred = 1;
1324             continue;
1325         }
1326
1327         if (matroska_parse_seekhead_entry(matroska, i) < 0) {
1328             // mark index as broken
1329             matroska->cues_parsing_deferred = -1;
1330             break;
1331         }
1332     }
1333 }
1334
1335 static void matroska_add_index_entries(MatroskaDemuxContext *matroska) {
1336     EbmlList *index_list;
1337     MatroskaIndex *index;
1338     int index_scale = 1;
1339     int i, j;
1340
1341     index_list = &matroska->index;
1342     index = index_list->elem;
1343     if (index_list->nb_elem
1344         && index[0].time > 1E14/matroska->time_scale) {
1345         av_log(matroska->ctx, AV_LOG_WARNING, "Working around broken index.\n");
1346         index_scale = matroska->time_scale;
1347     }
1348     for (i = 0; i < index_list->nb_elem; i++) {
1349         EbmlList *pos_list = &index[i].pos;
1350         MatroskaIndexPos *pos = pos_list->elem;
1351         for (j = 0; j < pos_list->nb_elem; j++) {
1352             MatroskaTrack *track = matroska_find_track_by_num(matroska, pos[j].track);
1353             if (track && track->stream)
1354                 av_add_index_entry(track->stream,
1355                                    pos[j].pos + matroska->segment_start,
1356                                    index[i].time/index_scale, 0, 0,
1357                                    AVINDEX_KEYFRAME);
1358         }
1359     }
1360 }
1361
1362 static void matroska_parse_cues(MatroskaDemuxContext *matroska) {
1363     EbmlList *seekhead_list = &matroska->seekhead;
1364     MatroskaSeekhead *seekhead = seekhead_list->elem;
1365     int i;
1366
1367     for (i = 0; i < seekhead_list->nb_elem; i++)
1368         if (seekhead[i].id == MATROSKA_ID_CUES)
1369             break;
1370     assert(i <= seekhead_list->nb_elem);
1371
1372     if (matroska_parse_seekhead_entry(matroska, i) < 0)
1373        matroska->cues_parsing_deferred = -1;
1374     matroska_add_index_entries(matroska);
1375 }
1376
1377 static int matroska_aac_profile(char *codec_id)
1378 {
1379     static const char * const aac_profiles[] = { "MAIN", "LC", "SSR" };
1380     int profile;
1381
1382     for (profile=0; profile<FF_ARRAY_ELEMS(aac_profiles); profile++)
1383         if (strstr(codec_id, aac_profiles[profile]))
1384             break;
1385     return profile + 1;
1386 }
1387
1388 static int matroska_aac_sri(int samplerate)
1389 {
1390     int sri;
1391
1392     for (sri=0; sri<FF_ARRAY_ELEMS(avpriv_mpeg4audio_sample_rates); sri++)
1393         if (avpriv_mpeg4audio_sample_rates[sri] == samplerate)
1394             break;
1395     return sri;
1396 }
1397
1398 static void matroska_metadata_creation_time(AVDictionary **metadata, int64_t date_utc)
1399 {
1400     char buffer[32];
1401     /* Convert to seconds and adjust by number of seconds between 2001-01-01 and Epoch */
1402     time_t creation_time = date_utc / 1000000000 + 978307200;
1403     struct tm *ptm = gmtime(&creation_time);
1404     if (!ptm) return;
1405     strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", ptm);
1406     av_dict_set(metadata, "creation_time", buffer, 0);
1407 }
1408
1409 static int matroska_read_header(AVFormatContext *s)
1410 {
1411     MatroskaDemuxContext *matroska = s->priv_data;
1412     EbmlList *attachements_list = &matroska->attachments;
1413     MatroskaAttachement *attachements;
1414     EbmlList *chapters_list = &matroska->chapters;
1415     MatroskaChapter *chapters;
1416     MatroskaTrack *tracks;
1417     uint64_t max_start = 0;
1418     int64_t pos;
1419     Ebml ebml = { 0 };
1420     AVStream *st;
1421     int i, j, k, res;
1422
1423     matroska->ctx = s;
1424
1425     /* First read the EBML header. */
1426     if (ebml_parse(matroska, ebml_syntax, &ebml)
1427         || ebml.version > EBML_VERSION       || ebml.max_size > sizeof(uint64_t)
1428         || ebml.id_length > sizeof(uint32_t) || ebml.doctype_version > 3 || !ebml.doctype) {
1429         av_log(matroska->ctx, AV_LOG_ERROR,
1430                "EBML header using unsupported features\n"
1431                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
1432                ebml.version, ebml.doctype, ebml.doctype_version);
1433         ebml_free(ebml_syntax, &ebml);
1434         return AVERROR_PATCHWELCOME;
1435     } else if (ebml.doctype_version == 3) {
1436         av_log(matroska->ctx, AV_LOG_WARNING,
1437                "EBML header using unsupported features\n"
1438                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
1439                ebml.version, ebml.doctype, ebml.doctype_version);
1440     }
1441     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++)
1442         if (!strcmp(ebml.doctype, matroska_doctypes[i]))
1443             break;
1444     if (i >= FF_ARRAY_ELEMS(matroska_doctypes)) {
1445         av_log(s, AV_LOG_WARNING, "Unknown EBML doctype '%s'\n", ebml.doctype);
1446     }
1447     ebml_free(ebml_syntax, &ebml);
1448
1449     /* The next thing is a segment. */
1450     pos = avio_tell(matroska->ctx->pb);
1451     res = ebml_parse(matroska, matroska_segments, matroska);
1452     // try resyncing until we find a EBML_STOP type element.
1453     while (res != 1) {
1454         res = matroska_resync(matroska, pos);
1455         if (res < 0)
1456             return res;
1457         pos = avio_tell(matroska->ctx->pb);
1458         res = ebml_parse(matroska, matroska_segment, matroska);
1459     }
1460     matroska_execute_seekhead(matroska);
1461
1462     if (!matroska->time_scale)
1463         matroska->time_scale = 1000000;
1464     if (matroska->duration)
1465         matroska->ctx->duration = matroska->duration * matroska->time_scale
1466                                   * 1000 / AV_TIME_BASE;
1467     av_dict_set(&s->metadata, "title", matroska->title, 0);
1468
1469     if (matroska->date_utc.size == 8)
1470         matroska_metadata_creation_time(&s->metadata, AV_RB64(matroska->date_utc.data));
1471
1472     tracks = matroska->tracks.elem;
1473     for (i=0; i < matroska->tracks.nb_elem; i++) {
1474         MatroskaTrack *track = &tracks[i];
1475         enum AVCodecID codec_id = AV_CODEC_ID_NONE;
1476         EbmlList *encodings_list = &track->encodings;
1477         MatroskaTrackEncoding *encodings = encodings_list->elem;
1478         uint8_t *extradata = NULL;
1479         int extradata_size = 0;
1480         int extradata_offset = 0;
1481         uint32_t fourcc = 0;
1482         AVIOContext b;
1483
1484         /* Apply some sanity checks. */
1485         if (track->type != MATROSKA_TRACK_TYPE_VIDEO &&
1486             track->type != MATROSKA_TRACK_TYPE_AUDIO &&
1487             track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
1488             av_log(matroska->ctx, AV_LOG_INFO,
1489                    "Unknown or unsupported track type %"PRIu64"\n",
1490                    track->type);
1491             continue;
1492         }
1493         if (track->codec_id == NULL)
1494             continue;
1495
1496         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1497             if (!track->default_duration && track->video.frame_rate > 0)
1498                 track->default_duration = 1000000000/track->video.frame_rate;
1499             if (!track->video.display_width)
1500                 track->video.display_width = track->video.pixel_width;
1501             if (!track->video.display_height)
1502                 track->video.display_height = track->video.pixel_height;
1503             if (track->video.color_space.size == 4)
1504                 fourcc = AV_RL32(track->video.color_space.data);
1505         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1506             if (!track->audio.out_samplerate)
1507                 track->audio.out_samplerate = track->audio.samplerate;
1508         }
1509         if (encodings_list->nb_elem > 1) {
1510             av_log(matroska->ctx, AV_LOG_ERROR,
1511                    "Multiple combined encodings not supported");
1512         } else if (encodings_list->nb_elem == 1) {
1513             if (encodings[0].type ||
1514                 (encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP &&
1515 #if CONFIG_ZLIB
1516                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_ZLIB &&
1517 #endif
1518 #if CONFIG_BZLIB
1519                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_BZLIB &&
1520 #endif
1521                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_LZO)) {
1522                 encodings[0].scope = 0;
1523                 av_log(matroska->ctx, AV_LOG_ERROR,
1524                        "Unsupported encoding type");
1525             } else if (track->codec_priv.size && encodings[0].scope&2) {
1526                 uint8_t *codec_priv = track->codec_priv.data;
1527                 int offset = matroska_decode_buffer(&track->codec_priv.data,
1528                                                     &track->codec_priv.size,
1529                                                     track);
1530                 if (offset < 0) {
1531                     track->codec_priv.data = NULL;
1532                     track->codec_priv.size = 0;
1533                     av_log(matroska->ctx, AV_LOG_ERROR,
1534                            "Failed to decode codec private data\n");
1535                 } else if (offset > 0) {
1536                     track->codec_priv.data = av_malloc(track->codec_priv.size + offset);
1537                     memcpy(track->codec_priv.data,
1538                            encodings[0].compression.settings.data, offset);
1539                     memcpy(track->codec_priv.data+offset, codec_priv,
1540                            track->codec_priv.size);
1541                     track->codec_priv.size += offset;
1542                 }
1543                 if (codec_priv != track->codec_priv.data)
1544                     av_free(codec_priv);
1545             }
1546         }
1547
1548         for(j=0; ff_mkv_codec_tags[j].id != AV_CODEC_ID_NONE; j++){
1549             if(!strncmp(ff_mkv_codec_tags[j].str, track->codec_id,
1550                         strlen(ff_mkv_codec_tags[j].str))){
1551                 codec_id= ff_mkv_codec_tags[j].id;
1552                 break;
1553             }
1554         }
1555
1556         st = track->stream = avformat_new_stream(s, NULL);
1557         if (st == NULL)
1558             return AVERROR(ENOMEM);
1559
1560         if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC")
1561             && track->codec_priv.size >= 40
1562             && track->codec_priv.data != NULL) {
1563             track->ms_compat = 1;
1564             fourcc = AV_RL32(track->codec_priv.data + 16);
1565             codec_id = ff_codec_get_id(ff_codec_bmp_tags, fourcc);
1566             extradata_offset = 40;
1567         } else if (!strcmp(track->codec_id, "A_MS/ACM")
1568                    && track->codec_priv.size >= 14
1569                    && track->codec_priv.data != NULL) {
1570             int ret;
1571             ffio_init_context(&b, track->codec_priv.data, track->codec_priv.size,
1572                           AVIO_FLAG_READ, NULL, NULL, NULL, NULL);
1573             ret = ff_get_wav_header(&b, st->codec, track->codec_priv.size);
1574             if (ret < 0)
1575                 return ret;
1576             codec_id = st->codec->codec_id;
1577             extradata_offset = FFMIN(track->codec_priv.size, 18);
1578         } else if (!strcmp(track->codec_id, "V_QUICKTIME")
1579                    && (track->codec_priv.size >= 86)
1580                    && (track->codec_priv.data != NULL)) {
1581             fourcc = AV_RL32(track->codec_priv.data);
1582             codec_id = ff_codec_get_id(ff_codec_movvideo_tags, fourcc);
1583         } else if (codec_id == AV_CODEC_ID_ALAC && track->codec_priv.size && track->codec_priv.size < INT_MAX-12) {
1584             /* Only ALAC's magic cookie is stored in Matroska's track headers.
1585                Create the "atom size", "tag", and "tag version" fields the
1586                decoder expects manually. */
1587             extradata_size = 12 + track->codec_priv.size;
1588             extradata = av_mallocz(extradata_size);
1589             if (extradata == NULL)
1590                 return AVERROR(ENOMEM);
1591             AV_WB32(extradata, extradata_size);
1592             memcpy(&extradata[4], "alac", 4);
1593             AV_WB32(&extradata[8], 0);
1594             memcpy(&extradata[12], track->codec_priv.data, track->codec_priv.size);
1595         } else if (codec_id == AV_CODEC_ID_PCM_S16BE) {
1596             switch (track->audio.bitdepth) {
1597             case  8:  codec_id = AV_CODEC_ID_PCM_U8;     break;
1598             case 24:  codec_id = AV_CODEC_ID_PCM_S24BE;  break;
1599             case 32:  codec_id = AV_CODEC_ID_PCM_S32BE;  break;
1600             }
1601         } else if (codec_id == AV_CODEC_ID_PCM_S16LE) {
1602             switch (track->audio.bitdepth) {
1603             case  8:  codec_id = AV_CODEC_ID_PCM_U8;     break;
1604             case 24:  codec_id = AV_CODEC_ID_PCM_S24LE;  break;
1605             case 32:  codec_id = AV_CODEC_ID_PCM_S32LE;  break;
1606             }
1607         } else if (codec_id==AV_CODEC_ID_PCM_F32LE && track->audio.bitdepth==64) {
1608             codec_id = AV_CODEC_ID_PCM_F64LE;
1609         } else if (codec_id == AV_CODEC_ID_AAC && !track->codec_priv.size) {
1610             int profile = matroska_aac_profile(track->codec_id);
1611             int sri = matroska_aac_sri(track->audio.samplerate);
1612             extradata = av_mallocz(5 + FF_INPUT_BUFFER_PADDING_SIZE);
1613             if (extradata == NULL)
1614                 return AVERROR(ENOMEM);
1615             extradata[0] = (profile << 3) | ((sri&0x0E) >> 1);
1616             extradata[1] = ((sri&0x01) << 7) | (track->audio.channels<<3);
1617             if (strstr(track->codec_id, "SBR")) {
1618                 sri = matroska_aac_sri(track->audio.out_samplerate);
1619                 extradata[2] = 0x56;
1620                 extradata[3] = 0xE5;
1621                 extradata[4] = 0x80 | (sri<<3);
1622                 extradata_size = 5;
1623             } else
1624                 extradata_size = 2;
1625         } else if (codec_id == AV_CODEC_ID_TTA) {
1626             extradata_size = 30;
1627             extradata = av_mallocz(extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
1628             if (extradata == NULL)
1629                 return AVERROR(ENOMEM);
1630             ffio_init_context(&b, extradata, extradata_size, 1,
1631                           NULL, NULL, NULL, NULL);
1632             avio_write(&b, "TTA1", 4);
1633             avio_wl16(&b, 1);
1634             avio_wl16(&b, track->audio.channels);
1635             avio_wl16(&b, track->audio.bitdepth);
1636             avio_wl32(&b, track->audio.out_samplerate);
1637             avio_wl32(&b, matroska->ctx->duration * track->audio.out_samplerate);
1638         } else if (codec_id == AV_CODEC_ID_RV10 || codec_id == AV_CODEC_ID_RV20 ||
1639                    codec_id == AV_CODEC_ID_RV30 || codec_id == AV_CODEC_ID_RV40) {
1640             extradata_offset = 26;
1641         } else if (codec_id == AV_CODEC_ID_RA_144) {
1642             track->audio.out_samplerate = 8000;
1643             track->audio.channels = 1;
1644         } else if ((codec_id == AV_CODEC_ID_RA_288 || codec_id == AV_CODEC_ID_COOK ||
1645                     codec_id == AV_CODEC_ID_ATRAC3 || codec_id == AV_CODEC_ID_SIPR)
1646                     && track->codec_priv.data) {
1647             int flavor;
1648
1649             ffio_init_context(&b, track->codec_priv.data,track->codec_priv.size,
1650                           0, NULL, NULL, NULL, NULL);
1651             avio_skip(&b, 22);
1652             flavor                       = avio_rb16(&b);
1653             track->audio.coded_framesize = avio_rb32(&b);
1654             avio_skip(&b, 12);
1655             track->audio.sub_packet_h    = avio_rb16(&b);
1656             track->audio.frame_size      = avio_rb16(&b);
1657             track->audio.sub_packet_size = avio_rb16(&b);
1658             track->audio.buf = av_malloc(track->audio.frame_size * track->audio.sub_packet_h);
1659             if (codec_id == AV_CODEC_ID_RA_288) {
1660                 st->codec->block_align = track->audio.coded_framesize;
1661                 track->codec_priv.size = 0;
1662             } else {
1663                 if (codec_id == AV_CODEC_ID_SIPR && flavor < 4) {
1664                     const int sipr_bit_rate[4] = { 6504, 8496, 5000, 16000 };
1665                     track->audio.sub_packet_size = ff_sipr_subpk_size[flavor];
1666                     st->codec->bit_rate = sipr_bit_rate[flavor];
1667                 }
1668                 st->codec->block_align = track->audio.sub_packet_size;
1669                 extradata_offset = 78;
1670             }
1671         }
1672         track->codec_priv.size -= extradata_offset;
1673
1674         if (codec_id == AV_CODEC_ID_NONE)
1675             av_log(matroska->ctx, AV_LOG_INFO,
1676                    "Unknown/unsupported AVCodecID %s.\n", track->codec_id);
1677
1678         if (track->time_scale < 0.01)
1679             track->time_scale = 1.0;
1680         avpriv_set_pts_info(st, 64, matroska->time_scale*track->time_scale, 1000*1000*1000); /* 64 bit pts in ns */
1681
1682         st->codec->codec_id = codec_id;
1683         st->start_time = 0;
1684         if (strcmp(track->language, "und"))
1685             av_dict_set(&st->metadata, "language", track->language, 0);
1686         av_dict_set(&st->metadata, "title", track->name, 0);
1687
1688         if (track->flag_default)
1689             st->disposition |= AV_DISPOSITION_DEFAULT;
1690         if (track->flag_forced)
1691             st->disposition |= AV_DISPOSITION_FORCED;
1692
1693         if (!st->codec->extradata) {
1694             if(extradata){
1695                 st->codec->extradata = extradata;
1696                 st->codec->extradata_size = extradata_size;
1697             } else if(track->codec_priv.data && track->codec_priv.size > 0){
1698                 st->codec->extradata = av_mallocz(track->codec_priv.size +
1699                                                   FF_INPUT_BUFFER_PADDING_SIZE);
1700                 if(st->codec->extradata == NULL)
1701                     return AVERROR(ENOMEM);
1702                 st->codec->extradata_size = track->codec_priv.size;
1703                 memcpy(st->codec->extradata,
1704                        track->codec_priv.data + extradata_offset,
1705                        track->codec_priv.size);
1706             }
1707         }
1708
1709         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1710             MatroskaTrackPlane *planes = track->operation.combine_planes.elem;
1711
1712             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
1713             st->codec->codec_tag  = fourcc;
1714             st->codec->width  = track->video.pixel_width;
1715             st->codec->height = track->video.pixel_height;
1716             av_reduce(&st->sample_aspect_ratio.num,
1717                       &st->sample_aspect_ratio.den,
1718                       st->codec->height * track->video.display_width,
1719                       st->codec-> width * track->video.display_height,
1720                       255);
1721             st->need_parsing = AVSTREAM_PARSE_HEADERS;
1722             if (track->default_duration) {
1723                 av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
1724                           1000000000, track->default_duration, 30000);
1725 #if FF_API_R_FRAME_RATE
1726                 st->r_frame_rate = st->avg_frame_rate;
1727 #endif
1728             }
1729
1730             /* export stereo mode flag as metadata tag */
1731             if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREO_MODE_COUNT)
1732                 av_dict_set(&st->metadata, "stereo_mode", matroska_video_stereo_mode[track->video.stereo_mode], 0);
1733
1734             /* if we have virtual track, mark the real tracks */
1735             for (j=0; j < track->operation.combine_planes.nb_elem; j++) {
1736                 char buf[32];
1737                 if (planes[j].type >= MATROSKA_VIDEO_STEREO_PLANE_COUNT)
1738                     continue;
1739                 snprintf(buf, sizeof(buf), "%s_%d",
1740                          matroska_video_stereo_plane[planes[j].type], i);
1741                 for (k=0; k < matroska->tracks.nb_elem; k++)
1742                     if (planes[j].uid == tracks[k].uid) {
1743                         av_dict_set(&s->streams[k]->metadata,
1744                                     "stereo_mode", buf, 0);
1745                         break;
1746                     }
1747             }
1748         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1749             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
1750             st->codec->sample_rate = track->audio.out_samplerate;
1751             st->codec->channels = track->audio.channels;
1752             if (st->codec->codec_id != AV_CODEC_ID_AAC)
1753             st->need_parsing = AVSTREAM_PARSE_HEADERS;
1754         } else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
1755             st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
1756             if (st->codec->codec_id == AV_CODEC_ID_SSA)
1757                 matroska->contains_ssa = 1;
1758         }
1759     }
1760
1761     attachements = attachements_list->elem;
1762     for (j=0; j<attachements_list->nb_elem; j++) {
1763         if (!(attachements[j].filename && attachements[j].mime &&
1764               attachements[j].bin.data && attachements[j].bin.size > 0)) {
1765             av_log(matroska->ctx, AV_LOG_ERROR, "incomplete attachment\n");
1766         } else {
1767             AVStream *st = avformat_new_stream(s, NULL);
1768             if (st == NULL)
1769                 break;
1770             av_dict_set(&st->metadata, "filename",attachements[j].filename, 0);
1771             av_dict_set(&st->metadata, "mimetype", attachements[j].mime, 0);
1772             st->codec->codec_id = AV_CODEC_ID_NONE;
1773             st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
1774             st->codec->extradata  = av_malloc(attachements[j].bin.size + FF_INPUT_BUFFER_PADDING_SIZE);
1775             if(st->codec->extradata == NULL)
1776                 break;
1777             st->codec->extradata_size = attachements[j].bin.size;
1778             memcpy(st->codec->extradata, attachements[j].bin.data, attachements[j].bin.size);
1779
1780             for (i=0; ff_mkv_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
1781                 if (!strncmp(ff_mkv_mime_tags[i].str, attachements[j].mime,
1782                              strlen(ff_mkv_mime_tags[i].str))) {
1783                     st->codec->codec_id = ff_mkv_mime_tags[i].id;
1784                     break;
1785                 }
1786             }
1787             attachements[j].stream = st;
1788         }
1789     }
1790
1791     chapters = chapters_list->elem;
1792     for (i=0; i<chapters_list->nb_elem; i++)
1793         if (chapters[i].start != AV_NOPTS_VALUE && chapters[i].uid
1794             && (max_start==0 || chapters[i].start > max_start)) {
1795             chapters[i].chapter =
1796             avpriv_new_chapter(s, chapters[i].uid, (AVRational){1, 1000000000},
1797                            chapters[i].start, chapters[i].end,
1798                            chapters[i].title);
1799             av_dict_set(&chapters[i].chapter->metadata,
1800                              "title", chapters[i].title, 0);
1801             max_start = chapters[i].start;
1802         }
1803
1804     matroska_add_index_entries(matroska);
1805
1806     matroska_convert_tags(s);
1807
1808     return 0;
1809 }
1810
1811 /*
1812  * Put one packet in an application-supplied AVPacket struct.
1813  * Returns 0 on success or -1 on failure.
1814  */
1815 static int matroska_deliver_packet(MatroskaDemuxContext *matroska,
1816                                    AVPacket *pkt)
1817 {
1818     if (matroska->num_packets > 0) {
1819         memcpy(pkt, matroska->packets[0], sizeof(AVPacket));
1820         av_free(matroska->packets[0]);
1821         if (matroska->num_packets > 1) {
1822             void *newpackets;
1823             memmove(&matroska->packets[0], &matroska->packets[1],
1824                     (matroska->num_packets - 1) * sizeof(AVPacket *));
1825             newpackets = av_realloc(matroska->packets,
1826                             (matroska->num_packets - 1) * sizeof(AVPacket *));
1827             if (newpackets)
1828                 matroska->packets = newpackets;
1829         } else {
1830             av_freep(&matroska->packets);
1831             matroska->prev_pkt = NULL;
1832         }
1833         matroska->num_packets--;
1834         return 0;
1835     }
1836
1837     return -1;
1838 }
1839
1840 /*
1841  * Free all packets in our internal queue.
1842  */
1843 static void matroska_clear_queue(MatroskaDemuxContext *matroska)
1844 {
1845     if (matroska->packets) {
1846         int n;
1847         for (n = 0; n < matroska->num_packets; n++) {
1848             av_free_packet(matroska->packets[n]);
1849             av_free(matroska->packets[n]);
1850         }
1851         av_freep(&matroska->packets);
1852         matroska->num_packets = 0;
1853     }
1854 }
1855
1856 static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
1857                                 int size, int64_t pos, uint64_t cluster_time,
1858                                 uint64_t duration, int is_keyframe,
1859                                 int64_t cluster_pos)
1860 {
1861     uint64_t timecode = AV_NOPTS_VALUE;
1862     MatroskaTrack *track;
1863     int res = 0;
1864     AVStream *st;
1865     AVPacket *pkt;
1866     int16_t block_time;
1867     uint32_t *lace_size = NULL;
1868     int n, flags, laces = 0;
1869     uint64_t num;
1870
1871     if ((n = matroska_ebmlnum_uint(matroska, data, size, &num)) < 0) {
1872         av_log(matroska->ctx, AV_LOG_ERROR, "EBML block data error\n");
1873         return n;
1874     }
1875     data += n;
1876     size -= n;
1877
1878     track = matroska_find_track_by_num(matroska, num);
1879     if (!track || !track->stream) {
1880         av_log(matroska->ctx, AV_LOG_INFO,
1881                "Invalid stream %"PRIu64" or size %u\n", num, size);
1882         return AVERROR_INVALIDDATA;
1883     } else if (size <= 3)
1884         return 0;
1885     st = track->stream;
1886     if (st->discard >= AVDISCARD_ALL)
1887         return res;
1888     av_assert1(duration != AV_NOPTS_VALUE);
1889
1890     block_time = AV_RB16(data);
1891     data += 2;
1892     flags = *data++;
1893     size -= 3;
1894     if (is_keyframe == -1)
1895         is_keyframe = flags & 0x80 ? AV_PKT_FLAG_KEY : 0;
1896
1897     if (cluster_time != (uint64_t)-1
1898         && (block_time >= 0 || cluster_time >= -block_time)) {
1899         timecode = cluster_time + block_time;
1900         if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE
1901             && timecode < track->end_timecode)
1902             is_keyframe = 0;  /* overlapping subtitles are not key frame */
1903         if (is_keyframe)
1904             av_add_index_entry(st, cluster_pos, timecode, 0,0,AVINDEX_KEYFRAME);
1905     }
1906
1907     if (matroska->skip_to_keyframe && track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
1908         if (timecode < matroska->skip_to_timecode)
1909             return res;
1910         if (!st->skip_to_keyframe) {
1911             av_log(matroska->ctx, AV_LOG_ERROR, "File is broken, keyframes not correctly marked!\n");
1912             matroska->skip_to_keyframe = 0;
1913         }
1914         if (is_keyframe)
1915             matroska->skip_to_keyframe = 0;
1916     }
1917
1918     switch ((flags & 0x06) >> 1) {
1919         case 0x0: /* no lacing */
1920             laces = 1;
1921             lace_size = av_mallocz(sizeof(int));
1922             lace_size[0] = size;
1923             break;
1924
1925         case 0x1: /* Xiph lacing */
1926         case 0x2: /* fixed-size lacing */
1927         case 0x3: /* EBML lacing */
1928             av_assert0(size>0); // size <=3 is checked before size-=3 above
1929             laces = (*data) + 1;
1930             data += 1;
1931             size -= 1;
1932             lace_size = av_mallocz(laces * sizeof(int));
1933
1934             switch ((flags & 0x06) >> 1) {
1935                 case 0x1: /* Xiph lacing */ {
1936                     uint8_t temp;
1937                     uint32_t total = 0;
1938                     for (n = 0; res == 0 && n < laces - 1; n++) {
1939                         while (1) {
1940                             if (size == 0) {
1941                                 res = -1;
1942                                 break;
1943                             }
1944                             temp = *data;
1945                             lace_size[n] += temp;
1946                             data += 1;
1947                             size -= 1;
1948                             if (temp != 0xff)
1949                                 break;
1950                         }
1951                         total += lace_size[n];
1952                     }
1953                     lace_size[n] = size - total;
1954                     break;
1955                 }
1956
1957                 case 0x2: /* fixed-size lacing */
1958                     for (n = 0; n < laces; n++)
1959                         lace_size[n] = size / laces;
1960                     break;
1961
1962                 case 0x3: /* EBML lacing */ {
1963                     uint32_t total;
1964                     n = matroska_ebmlnum_uint(matroska, data, size, &num);
1965                     if (n < 0) {
1966                         av_log(matroska->ctx, AV_LOG_INFO,
1967                                "EBML block data error\n");
1968                         break;
1969                     }
1970                     data += n;
1971                     size -= n;
1972                     total = lace_size[0] = num;
1973                     for (n = 1; res == 0 && n < laces - 1; n++) {
1974                         int64_t snum;
1975                         int r;
1976                         r = matroska_ebmlnum_sint(matroska, data, size, &snum);
1977                         if (r < 0) {
1978                             av_log(matroska->ctx, AV_LOG_INFO,
1979                                    "EBML block data error\n");
1980                             break;
1981                         }
1982                         data += r;
1983                         size -= r;
1984                         lace_size[n] = lace_size[n - 1] + snum;
1985                         total += lace_size[n];
1986                     }
1987                     lace_size[laces - 1] = size - total;
1988                     break;
1989                 }
1990             }
1991             break;
1992     }
1993
1994     if (res == 0) {
1995         if (!duration)
1996             duration = track->default_duration * laces / matroska->time_scale;
1997
1998         if (cluster_time != (uint64_t)-1 && (block_time >= 0 || cluster_time >= -block_time))
1999             track->end_timecode = FFMAX(track->end_timecode, timecode+duration);
2000
2001         for (n = 0; n < laces; n++) {
2002             int64_t lace_duration = duration*(n+1) / laces - duration*n / laces;
2003
2004             if (lace_size[n] > size) {
2005                 av_log(matroska->ctx, AV_LOG_ERROR, "Invalid packet size\n");
2006                 break;
2007             }
2008
2009             if ((st->codec->codec_id == AV_CODEC_ID_RA_288 ||
2010                  st->codec->codec_id == AV_CODEC_ID_COOK ||
2011                  st->codec->codec_id == AV_CODEC_ID_SIPR ||
2012                  st->codec->codec_id == AV_CODEC_ID_ATRAC3) &&
2013                  st->codec->block_align && track->audio.sub_packet_size) {
2014                 int a = st->codec->block_align;
2015                 int sps = track->audio.sub_packet_size;
2016                 int cfs = track->audio.coded_framesize;
2017                 int h = track->audio.sub_packet_h;
2018                 int y = track->audio.sub_packet_cnt;
2019                 int w = track->audio.frame_size;
2020                 int x;
2021
2022                 if (!track->audio.pkt_cnt) {
2023                     if (track->audio.sub_packet_cnt == 0)
2024                         track->audio.buf_timecode = timecode;
2025                     if (st->codec->codec_id == AV_CODEC_ID_RA_288) {
2026                         if (size < cfs * h / 2) {
2027                             av_log(matroska->ctx, AV_LOG_ERROR,
2028                                    "Corrupt int4 RM-style audio packet size\n");
2029                             res = AVERROR_INVALIDDATA;
2030                             goto end;
2031                         }
2032                         for (x=0; x<h/2; x++)
2033                             memcpy(track->audio.buf+x*2*w+y*cfs,
2034                                    data+x*cfs, cfs);
2035                     } else if (st->codec->codec_id == AV_CODEC_ID_SIPR) {
2036                         if (size < w) {
2037                             av_log(matroska->ctx, AV_LOG_ERROR,
2038                                    "Corrupt sipr RM-style audio packet size\n");
2039                             res = AVERROR_INVALIDDATA;
2040                             goto end;
2041                         }
2042                         memcpy(track->audio.buf + y*w, data, w);
2043                     } else {
2044                         if (size < sps * w / sps) {
2045                             av_log(matroska->ctx, AV_LOG_ERROR,
2046                                    "Corrupt generic RM-style audio packet size\n");
2047                             res = AVERROR_INVALIDDATA;
2048                             goto end;
2049                         }
2050                         for (x=0; x<w/sps; x++)
2051                             memcpy(track->audio.buf+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), data+x*sps, sps);
2052                     }
2053
2054                     if (++track->audio.sub_packet_cnt >= h) {
2055                         if (st->codec->codec_id == AV_CODEC_ID_SIPR)
2056                             ff_rm_reorder_sipr_data(track->audio.buf, h, w);
2057                         track->audio.sub_packet_cnt = 0;
2058                         track->audio.pkt_cnt = h*w / a;
2059                     }
2060                 }
2061                 while (track->audio.pkt_cnt) {
2062                     pkt = av_mallocz(sizeof(AVPacket));
2063                     av_new_packet(pkt, a);
2064                     memcpy(pkt->data, track->audio.buf
2065                            + a * (h*w / a - track->audio.pkt_cnt--), a);
2066                     pkt->pts = track->audio.buf_timecode;
2067                     track->audio.buf_timecode = AV_NOPTS_VALUE;
2068                     pkt->pos = pos;
2069                     pkt->stream_index = st->index;
2070                     dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
2071                 }
2072             } else {
2073                 MatroskaTrackEncoding *encodings = track->encodings.elem;
2074                 int offset = 0;
2075                 uint32_t pkt_size = lace_size[n];
2076                 uint8_t *pkt_data = data;
2077
2078                 if (encodings && encodings->scope & 1) {
2079                     offset = matroska_decode_buffer(&pkt_data,&pkt_size, track);
2080                     if (offset < 0)
2081                         continue;
2082                     av_assert0(offset + pkt_size >= pkt_size);
2083                 }
2084
2085                 pkt = av_mallocz(sizeof(AVPacket));
2086                 /* XXX: prevent data copy... */
2087                 if (av_new_packet(pkt, pkt_size+offset) < 0) {
2088                     av_free(pkt);
2089                     res = AVERROR(ENOMEM);
2090                     break;
2091                 }
2092                 if (offset)
2093                     memcpy (pkt->data, encodings->compression.settings.data, offset);
2094                 memcpy (pkt->data+offset, pkt_data, pkt_size);
2095
2096                 if (pkt_data != data)
2097                     av_free(pkt_data);
2098
2099                 if (n == 0)
2100                     pkt->flags = is_keyframe;
2101                 pkt->stream_index = st->index;
2102
2103                 if (track->ms_compat)
2104                     pkt->dts = timecode;
2105                 else
2106                     pkt->pts = timecode;
2107                 pkt->pos = pos;
2108                 if (st->codec->codec_id == AV_CODEC_ID_TEXT)
2109                     pkt->convergence_duration = lace_duration;
2110                 else if (track->type != MATROSKA_TRACK_TYPE_SUBTITLE)
2111                     pkt->duration = lace_duration;
2112
2113                 if (st->codec->codec_id == AV_CODEC_ID_SSA)
2114                     matroska_fix_ass_packet(matroska, pkt, lace_duration);
2115
2116                 if (matroska->prev_pkt &&
2117                     timecode != AV_NOPTS_VALUE &&
2118                     matroska->prev_pkt->pts == timecode &&
2119                     matroska->prev_pkt->stream_index == st->index &&
2120                     st->codec->codec_id == AV_CODEC_ID_SSA)
2121                     matroska_merge_packets(matroska->prev_pkt, pkt);
2122                 else {
2123                     dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
2124                     matroska->prev_pkt = pkt;
2125                 }
2126             }
2127
2128             if (timecode != AV_NOPTS_VALUE)
2129                 timecode = lace_duration ? timecode + lace_duration : AV_NOPTS_VALUE;
2130             data += lace_size[n];
2131             size -= lace_size[n];
2132         }
2133     }
2134
2135 end:
2136     av_free(lace_size);
2137     return res;
2138 }
2139
2140 static int matroska_parse_cluster_incremental(MatroskaDemuxContext *matroska)
2141 {
2142     EbmlList *blocks_list;
2143     MatroskaBlock *blocks;
2144     int i, res;
2145     res = ebml_parse(matroska,
2146                      matroska_cluster_incremental_parsing,
2147                      &matroska->current_cluster);
2148     if (res == 1) {
2149         /* New Cluster */
2150         if (matroska->current_cluster_pos)
2151             ebml_level_end(matroska);
2152         ebml_free(matroska_cluster, &matroska->current_cluster);
2153         memset(&matroska->current_cluster, 0, sizeof(MatroskaCluster));
2154         matroska->current_cluster_num_blocks = 0;
2155         matroska->current_cluster_pos = avio_tell(matroska->ctx->pb);
2156         matroska->prev_pkt = NULL;
2157         /* sizeof the ID which was already read */
2158         if (matroska->current_id)
2159             matroska->current_cluster_pos -= 4;
2160         res = ebml_parse(matroska,
2161                          matroska_clusters_incremental,
2162                          &matroska->current_cluster);
2163         /* Try parsing the block again. */
2164         if (res == 1)
2165             res = ebml_parse(matroska,
2166                              matroska_cluster_incremental_parsing,
2167                              &matroska->current_cluster);
2168     }
2169
2170     if (!res &&
2171         matroska->current_cluster_num_blocks <
2172             matroska->current_cluster.blocks.nb_elem) {
2173         blocks_list = &matroska->current_cluster.blocks;
2174         blocks = blocks_list->elem;
2175
2176         matroska->current_cluster_num_blocks = blocks_list->nb_elem;
2177         i = blocks_list->nb_elem - 1;
2178         if (blocks[i].bin.size > 0 && blocks[i].bin.data) {
2179             int is_keyframe = blocks[i].non_simple ? !blocks[i].reference : -1;
2180             if (!blocks[i].non_simple)
2181                 blocks[i].duration = 0;
2182             res = matroska_parse_block(matroska,
2183                                        blocks[i].bin.data, blocks[i].bin.size,
2184                                        blocks[i].bin.pos,
2185                                        matroska->current_cluster.timecode,
2186                                        blocks[i].duration, is_keyframe,
2187                                        matroska->current_cluster_pos);
2188         }
2189     }
2190
2191     if (res < 0)  matroska->done = 1;
2192     return res;
2193 }
2194
2195 static int matroska_parse_cluster(MatroskaDemuxContext *matroska)
2196 {
2197     MatroskaCluster cluster = { 0 };
2198     EbmlList *blocks_list;
2199     MatroskaBlock *blocks;
2200     int i, res;
2201     int64_t pos;
2202     if (!matroska->contains_ssa)
2203         return matroska_parse_cluster_incremental(matroska);
2204     pos = avio_tell(matroska->ctx->pb);
2205     matroska->prev_pkt = NULL;
2206     if (matroska->current_id)
2207         pos -= 4;  /* sizeof the ID which was already read */
2208     res = ebml_parse(matroska, matroska_clusters, &cluster);
2209     blocks_list = &cluster.blocks;
2210     blocks = blocks_list->elem;
2211     for (i=0; i<blocks_list->nb_elem; i++)
2212         if (blocks[i].bin.size > 0 && blocks[i].bin.data) {
2213             int is_keyframe = blocks[i].non_simple ? !blocks[i].reference : -1;
2214             res=matroska_parse_block(matroska,
2215                                      blocks[i].bin.data, blocks[i].bin.size,
2216                                      blocks[i].bin.pos,  cluster.timecode,
2217                                      blocks[i].duration, is_keyframe,
2218                                      pos);
2219         }
2220     ebml_free(matroska_cluster, &cluster);
2221     return res;
2222 }
2223
2224 static int matroska_read_packet(AVFormatContext *s, AVPacket *pkt)
2225 {
2226     MatroskaDemuxContext *matroska = s->priv_data;
2227
2228     while (matroska_deliver_packet(matroska, pkt)) {
2229         int64_t pos = avio_tell(matroska->ctx->pb);
2230         if (matroska->done)
2231             return AVERROR_EOF;
2232         if (matroska_parse_cluster(matroska) < 0)
2233             matroska_resync(matroska, pos);
2234     }
2235
2236     return 0;
2237 }
2238
2239 static int matroska_read_seek(AVFormatContext *s, int stream_index,
2240                               int64_t timestamp, int flags)
2241 {
2242     MatroskaDemuxContext *matroska = s->priv_data;
2243     MatroskaTrack *tracks = matroska->tracks.elem;
2244     AVStream *st = s->streams[stream_index];
2245     int i, index, index_sub, index_min;
2246
2247     /* Parse the CUES now since we need the index data to seek. */
2248     if (matroska->cues_parsing_deferred > 0) {
2249         matroska->cues_parsing_deferred = 0;
2250         matroska_parse_cues(matroska);
2251     }
2252
2253     if (!st->nb_index_entries)
2254         goto err;
2255     timestamp = FFMAX(timestamp, st->index_entries[0].timestamp);
2256
2257     if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
2258         avio_seek(s->pb, st->index_entries[st->nb_index_entries-1].pos, SEEK_SET);
2259         matroska->current_id = 0;
2260         while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
2261             matroska->prev_pkt = NULL;
2262             matroska_clear_queue(matroska);
2263             if (matroska_parse_cluster(matroska) < 0)
2264                 break;
2265         }
2266     }
2267
2268     matroska_clear_queue(matroska);
2269     if (index < 0 || (matroska->cues_parsing_deferred < 0 && index == st->nb_index_entries - 1))
2270         goto err;
2271
2272     index_min = index;
2273     for (i=0; i < matroska->tracks.nb_elem; i++) {
2274         tracks[i].audio.pkt_cnt = 0;
2275         tracks[i].audio.sub_packet_cnt = 0;
2276         tracks[i].audio.buf_timecode = AV_NOPTS_VALUE;
2277         tracks[i].end_timecode = 0;
2278         if (tracks[i].type == MATROSKA_TRACK_TYPE_SUBTITLE
2279             && !tracks[i].stream->discard != AVDISCARD_ALL) {
2280             index_sub = av_index_search_timestamp(tracks[i].stream, st->index_entries[index].timestamp, AVSEEK_FLAG_BACKWARD);
2281             if (index_sub >= 0
2282                 && st->index_entries[index_sub].pos < st->index_entries[index_min].pos
2283                 && st->index_entries[index].timestamp - st->index_entries[index_sub].timestamp < 30000000000/matroska->time_scale)
2284                 index_min = index_sub;
2285         }
2286     }
2287
2288     avio_seek(s->pb, st->index_entries[index_min].pos, SEEK_SET);
2289     matroska->current_id = 0;
2290     st->skip_to_keyframe =
2291     matroska->skip_to_keyframe = !(flags & AVSEEK_FLAG_ANY);
2292     matroska->skip_to_timecode = st->index_entries[index].timestamp;
2293     matroska->done = 0;
2294     matroska->num_levels = 0;
2295     ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
2296     return 0;
2297 err:
2298     // slightly hackish but allows proper fallback to
2299     // the generic seeking code.
2300     matroska_clear_queue(matroska);
2301     matroska->current_id = 0;
2302     st->skip_to_keyframe =
2303     matroska->skip_to_keyframe = 0;
2304     matroska->done = 0;
2305     matroska->num_levels = 0;
2306     return -1;
2307 }
2308
2309 static int matroska_read_close(AVFormatContext *s)
2310 {
2311     MatroskaDemuxContext *matroska = s->priv_data;
2312     MatroskaTrack *tracks = matroska->tracks.elem;
2313     int n;
2314
2315     matroska_clear_queue(matroska);
2316
2317     for (n=0; n < matroska->tracks.nb_elem; n++)
2318         if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)
2319             av_free(tracks[n].audio.buf);
2320     ebml_free(matroska_cluster, &matroska->current_cluster);
2321     ebml_free(matroska_segment, matroska);
2322
2323     return 0;
2324 }
2325
2326 AVInputFormat ff_matroska_demuxer = {
2327     .name           = "matroska,webm",
2328     .long_name      = NULL_IF_CONFIG_SMALL("Matroska / WebM"),
2329     .priv_data_size = sizeof(MatroskaDemuxContext),
2330     .read_probe     = matroska_probe,
2331     .read_header    = matroska_read_header,
2332     .read_packet    = matroska_read_packet,
2333     .read_close     = matroska_read_close,
2334     .read_seek      = matroska_read_seek,
2335 };