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     AVFormatContext *ctx;
 228
 229     /* EBML stuff */
 230     int num_levels;
 231     MatroskaLevel levels[EBML_MAX_DEPTH];
 232     int level_up;
 233     uint32_t current_id;
 234
 235     uint64_t time_scale;
 236     double   duration;
 237     char    *title;
 238     EbmlList tracks;
 239     EbmlList attachments;
 240     EbmlList chapters;
 241     EbmlList index;
 242     EbmlList tags;
 243     EbmlList seekhead;
 244
 245     /* byte position of the segment inside the stream */
 246     int64_t segment_start;
 247
 248     /* the packet queue */
 249     AVPacket **packets;
 250     int num_packets;
 251     AVPacket *prev_pkt;
 252
 253     int done;
 254
 255     /* What to skip before effectively reading a packet. */
 256     int skip_to_keyframe;
 257     uint64_t skip_to_timecode;
 258
 259     /* File has a CUES element, but we defer parsing until it is needed. */
 260     int cues_parsing_deferred;
 261 } MatroskaDemuxContext;
 262
 263 typedef struct {
 264     uint64_t duration;
 265     int64_t  reference;
 266     uint64_t non_simple;
 267     EbmlBin  bin;
 268 } MatroskaBlock;
 269
 270 typedef struct {
 271     uint64_t timecode;
 272     EbmlList blocks;
 273 } MatroskaCluster;
 274
 275 static EbmlSyntax ebml_header[] = {
 276     { EBML_ID_EBMLREADVERSION,        EBML_UINT, 0, offsetof(Ebml,version), {.u=EBML_VERSION} },
 277     { EBML_ID_EBMLMAXSIZELENGTH,      EBML_UINT, 0, offsetof(Ebml,max_size), {.u=8} },
 278     { EBML_ID_EBMLMAXIDLENGTH,        EBML_UINT, 0, offsetof(Ebml,id_length), {.u=4} },
 279     { EBML_ID_DOCTYPE,                EBML_STR,  0, offsetof(Ebml,doctype), {.s="(none)"} },
 280     { EBML_ID_DOCTYPEREADVERSION,     EBML_UINT, 0, offsetof(Ebml,doctype_version), {.u=1} },
 281     { EBML_ID_EBMLVERSION,            EBML_NONE },
 282     { EBML_ID_DOCTYPEVERSION,         EBML_NONE },
 283     { 0 }
 284 };
 285
 286 static EbmlSyntax ebml_syntax[] = {
 287     { EBML_ID_HEADER,                 EBML_NEST, 0, 0, {.n=ebml_header} },
 288     { 0 }
 289 };
 290
 291 static EbmlSyntax matroska_info[] = {
 292     { MATROSKA_ID_TIMECODESCALE,      EBML_UINT,  0, offsetof(MatroskaDemuxContext,time_scale), {.u=1000000} },
 293     { MATROSKA_ID_DURATION,           EBML_FLOAT, 0, offsetof(MatroskaDemuxContext,duration) },
 294     { MATROSKA_ID_TITLE,              EBML_UTF8,  0, offsetof(MatroskaDemuxContext,title) },
 295     { MATROSKA_ID_WRITINGAPP,         EBML_NONE },
 296     { MATROSKA_ID_MUXINGAPP,          EBML_NONE },
 297     { MATROSKA_ID_DATEUTC,            EBML_NONE },
 298     { MATROSKA_ID_SEGMENTUID,         EBML_NONE },
 299     { 0 }
 300 };
 301
 302 static EbmlSyntax matroska_track_video[] = {
 303     { MATROSKA_ID_VIDEOFRAMERATE,     EBML_FLOAT,0, offsetof(MatroskaTrackVideo,frame_rate) },
 304     { MATROSKA_ID_VIDEODISPLAYWIDTH,  EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_width) },
 305     { MATROSKA_ID_VIDEODISPLAYHEIGHT, EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_height) },
 306     { MATROSKA_ID_VIDEOPIXELWIDTH,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_width) },
 307     { MATROSKA_ID_VIDEOPIXELHEIGHT,   EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_height) },
 308     { MATROSKA_ID_VIDEOCOLORSPACE,    EBML_BIN,  0, offsetof(MatroskaTrackVideo,color_space) },
 309     { MATROSKA_ID_VIDEOSTEREOMODE,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,stereo_mode) },
 310     { MATROSKA_ID_VIDEOPIXELCROPB,    EBML_NONE },
 311     { MATROSKA_ID_VIDEOPIXELCROPT,    EBML_NONE },
 312     { MATROSKA_ID_VIDEOPIXELCROPL,    EBML_NONE },
 313     { MATROSKA_ID_VIDEOPIXELCROPR,    EBML_NONE },
 314     { MATROSKA_ID_VIDEODISPLAYUNIT,   EBML_NONE },
 315     { MATROSKA_ID_VIDEOFLAGINTERLACED,EBML_NONE },
 316     { MATROSKA_ID_VIDEOASPECTRATIO,   EBML_NONE },
 317     { 0 }
 318 };
 319
 320 static EbmlSyntax matroska_track_audio[] = {
 321     { MATROSKA_ID_AUDIOSAMPLINGFREQ,  EBML_FLOAT,0, offsetof(MatroskaTrackAudio,samplerate), {.f=8000.0} },
 322     { MATROSKA_ID_AUDIOOUTSAMPLINGFREQ,EBML_FLOAT,0,offsetof(MatroskaTrackAudio,out_samplerate) },
 323     { MATROSKA_ID_AUDIOBITDEPTH,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,bitdepth) },
 324     { MATROSKA_ID_AUDIOCHANNELS,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,channels), {.u=1} },
 325     { 0 }
 326 };
 327
 328 static EbmlSyntax matroska_track_encoding_compression[] = {
 329     { MATROSKA_ID_ENCODINGCOMPALGO,   EBML_UINT, 0, offsetof(MatroskaTrackCompression,algo), {.u=0} },
 330     { MATROSKA_ID_ENCODINGCOMPSETTINGS,EBML_BIN, 0, offsetof(MatroskaTrackCompression,settings) },
 331     { 0 }
 332 };
 333
 334 static EbmlSyntax matroska_track_encoding[] = {
 335     { MATROSKA_ID_ENCODINGSCOPE,      EBML_UINT, 0, offsetof(MatroskaTrackEncoding,scope), {.u=1} },
 336     { MATROSKA_ID_ENCODINGTYPE,       EBML_UINT, 0, offsetof(MatroskaTrackEncoding,type), {.u=0} },
 337     { MATROSKA_ID_ENCODINGCOMPRESSION,EBML_NEST, 0, offsetof(MatroskaTrackEncoding,compression), {.n=matroska_track_encoding_compression} },
 338     { MATROSKA_ID_ENCODINGORDER,      EBML_NONE },
 339     { 0 }
 340 };
 341
 342 static EbmlSyntax matroska_track_encodings[] = {
 343     { MATROSKA_ID_TRACKCONTENTENCODING, EBML_NEST, sizeof(MatroskaTrackEncoding), offsetof(MatroskaTrack,encodings), {.n=matroska_track_encoding} },
 344     { 0 }
 345 };
 346
 347 static EbmlSyntax matroska_track_plane[] = {
 348     { MATROSKA_ID_TRACKPLANEUID,  EBML_UINT, 0, offsetof(MatroskaTrackPlane,uid) },
 349     { MATROSKA_ID_TRACKPLANETYPE, EBML_UINT, 0, offsetof(MatroskaTrackPlane,type) },
 350     { 0 }
 351 };
 352
 353 static EbmlSyntax matroska_track_combine_planes[] = {
 354     { MATROSKA_ID_TRACKPLANE, EBML_NEST, sizeof(MatroskaTrackPlane), offsetof(MatroskaTrackOperation,combine_planes), {.n=matroska_track_plane} },
 355     { 0 }
 356 };
 357
 358 static EbmlSyntax matroska_track_operation[] = {
 359     { MATROSKA_ID_TRACKCOMBINEPLANES, EBML_NEST, 0, 0, {.n=matroska_track_combine_planes} },
 360     { 0 }
 361 };
 362
 363 static EbmlSyntax matroska_track[] = {
 364     { MATROSKA_ID_TRACKNUMBER,          EBML_UINT, 0, offsetof(MatroskaTrack,num) },
 365     { MATROSKA_ID_TRACKNAME,            EBML_UTF8, 0, offsetof(MatroskaTrack,name) },
 366     { MATROSKA_ID_TRACKUID,             EBML_UINT, 0, offsetof(MatroskaTrack,uid) },
 367     { MATROSKA_ID_TRACKTYPE,            EBML_UINT, 0, offsetof(MatroskaTrack,type) },
 368     { MATROSKA_ID_CODECID,              EBML_STR,  0, offsetof(MatroskaTrack,codec_id) },
 369     { MATROSKA_ID_CODECPRIVATE,         EBML_BIN,  0, offsetof(MatroskaTrack,codec_priv) },
 370     { MATROSKA_ID_TRACKLANGUAGE,        EBML_UTF8, 0, offsetof(MatroskaTrack,language), {.s="eng"} },
 371     { MATROSKA_ID_TRACKDEFAULTDURATION, EBML_UINT, 0, offsetof(MatroskaTrack,default_duration) },
 372     { MATROSKA_ID_TRACKTIMECODESCALE,   EBML_FLOAT,0, offsetof(MatroskaTrack,time_scale), {.f=1.0} },
 373     { MATROSKA_ID_TRACKFLAGDEFAULT,     EBML_UINT, 0, offsetof(MatroskaTrack,flag_default), {.u=1} },
 374     { MATROSKA_ID_TRACKFLAGFORCED,      EBML_UINT, 0, offsetof(MatroskaTrack,flag_forced), {.u=0} },
 375     { MATROSKA_ID_TRACKVIDEO,           EBML_NEST, 0, offsetof(MatroskaTrack,video), {.n=matroska_track_video} },
 376     { MATROSKA_ID_TRACKAUDIO,           EBML_NEST, 0, offsetof(MatroskaTrack,audio), {.n=matroska_track_audio} },
 377     { MATROSKA_ID_TRACKOPERATION,       EBML_NEST, 0, offsetof(MatroskaTrack,operation), {.n=matroska_track_operation} },
 378     { MATROSKA_ID_TRACKCONTENTENCODINGS,EBML_NEST, 0, 0, {.n=matroska_track_encodings} },
 379     { MATROSKA_ID_TRACKFLAGENABLED,     EBML_NONE },
 380     { MATROSKA_ID_TRACKFLAGLACING,      EBML_NONE },
 381     { MATROSKA_ID_CODECNAME,            EBML_NONE },
 382     { MATROSKA_ID_CODECDECODEALL,       EBML_NONE },
 383     { MATROSKA_ID_CODECINFOURL,         EBML_NONE },
 384     { MATROSKA_ID_CODECDOWNLOADURL,     EBML_NONE },
 385     { MATROSKA_ID_TRACKMINCACHE,        EBML_NONE },
 386     { MATROSKA_ID_TRACKMAXCACHE,        EBML_NONE },
 387     { MATROSKA_ID_TRACKMAXBLKADDID,     EBML_NONE },
 388     { 0 }
 389 };
 390
 391 static EbmlSyntax matroska_tracks[] = {
 392     { MATROSKA_ID_TRACKENTRY,         EBML_NEST, sizeof(MatroskaTrack), offsetof(MatroskaDemuxContext,tracks), {.n=matroska_track} },
 393     { 0 }
 394 };
 395
 396 static EbmlSyntax matroska_attachment[] = {
 397     { MATROSKA_ID_FILEUID,            EBML_UINT, 0, offsetof(MatroskaAttachement,uid) },
 398     { MATROSKA_ID_FILENAME,           EBML_UTF8, 0, offsetof(MatroskaAttachement,filename) },
 399     { MATROSKA_ID_FILEMIMETYPE,       EBML_STR,  0, offsetof(MatroskaAttachement,mime) },
 400     { MATROSKA_ID_FILEDATA,           EBML_BIN,  0, offsetof(MatroskaAttachement,bin) },
 401     { MATROSKA_ID_FILEDESC,           EBML_NONE },
 402     { 0 }
 403 };
 404
 405 static EbmlSyntax matroska_attachments[] = {
 406     { MATROSKA_ID_ATTACHEDFILE,       EBML_NEST, sizeof(MatroskaAttachement), offsetof(MatroskaDemuxContext,attachments), {.n=matroska_attachment} },
 407     { 0 }
 408 };
 409
 410 static EbmlSyntax matroska_chapter_display[] = {
 411     { MATROSKA_ID_CHAPSTRING,         EBML_UTF8, 0, offsetof(MatroskaChapter,title) },
 412     { MATROSKA_ID_CHAPLANG,           EBML_NONE },
 413     { 0 }
 414 };
 415
 416 static EbmlSyntax matroska_chapter_entry[] = {
 417     { MATROSKA_ID_CHAPTERTIMESTART,   EBML_UINT, 0, offsetof(MatroskaChapter,start), {.u=AV_NOPTS_VALUE} },
 418     { MATROSKA_ID_CHAPTERTIMEEND,     EBML_UINT, 0, offsetof(MatroskaChapter,end), {.u=AV_NOPTS_VALUE} },
 419     { MATROSKA_ID_CHAPTERUID,         EBML_UINT, 0, offsetof(MatroskaChapter,uid) },
 420     { MATROSKA_ID_CHAPTERDISPLAY,     EBML_NEST, 0, 0, {.n=matroska_chapter_display} },
 421     { MATROSKA_ID_CHAPTERFLAGHIDDEN,  EBML_NONE },
 422     { MATROSKA_ID_CHAPTERFLAGENABLED, EBML_NONE },
 423     { MATROSKA_ID_CHAPTERPHYSEQUIV,   EBML_NONE },
 424     { MATROSKA_ID_CHAPTERATOM,        EBML_NONE },
 425     { 0 }
 426 };
 427
 428 static EbmlSyntax matroska_chapter[] = {
 429     { MATROSKA_ID_CHAPTERATOM,        EBML_NEST, sizeof(MatroskaChapter), offsetof(MatroskaDemuxContext,chapters), {.n=matroska_chapter_entry} },
 430     { MATROSKA_ID_EDITIONUID,         EBML_NONE },
 431     { MATROSKA_ID_EDITIONFLAGHIDDEN,  EBML_NONE },
 432     { MATROSKA_ID_EDITIONFLAGDEFAULT, EBML_NONE },
 433     { MATROSKA_ID_EDITIONFLAGORDERED, EBML_NONE },
 434     { 0 }
 435 };
 436
 437 static EbmlSyntax matroska_chapters[] = {
 438     { MATROSKA_ID_EDITIONENTRY,       EBML_NEST, 0, 0, {.n=matroska_chapter} },
 439     { 0 }
 440 };
 441
 442 static EbmlSyntax matroska_index_pos[] = {
 443     { MATROSKA_ID_CUETRACK,           EBML_UINT, 0, offsetof(MatroskaIndexPos,track) },
 444     { MATROSKA_ID_CUECLUSTERPOSITION, EBML_UINT, 0, offsetof(MatroskaIndexPos,pos)   },
 445     { MATROSKA_ID_CUEBLOCKNUMBER,     EBML_NONE },
 446     { 0 }
 447 };
 448
 449 static EbmlSyntax matroska_index_entry[] = {
 450     { MATROSKA_ID_CUETIME,            EBML_UINT, 0, offsetof(MatroskaIndex,time) },
 451     { MATROSKA_ID_CUETRACKPOSITION,   EBML_NEST, sizeof(MatroskaIndexPos), offsetof(MatroskaIndex,pos), {.n=matroska_index_pos} },
 452     { 0 }
 453 };
 454
 455 static EbmlSyntax matroska_index[] = {
 456     { MATROSKA_ID_POINTENTRY,         EBML_NEST, sizeof(MatroskaIndex), offsetof(MatroskaDemuxContext,index), {.n=matroska_index_entry} },
 457     { 0 }
 458 };
 459
 460 static EbmlSyntax matroska_simpletag[] = {
 461     { MATROSKA_ID_TAGNAME,            EBML_UTF8, 0, offsetof(MatroskaTag,name) },
 462     { MATROSKA_ID_TAGSTRING,          EBML_UTF8, 0, offsetof(MatroskaTag,string) },
 463     { MATROSKA_ID_TAGLANG,            EBML_STR,  0, offsetof(MatroskaTag,lang), {.s="und"} },
 464     { MATROSKA_ID_TAGDEFAULT,         EBML_UINT, 0, offsetof(MatroskaTag,def) },
 465     { MATROSKA_ID_TAGDEFAULT_BUG,     EBML_UINT, 0, offsetof(MatroskaTag,def) },
 466     { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTag,sub), {.n=matroska_simpletag} },
 467     { 0 }
 468 };
 469
 470 static EbmlSyntax matroska_tagtargets[] = {
 471     { MATROSKA_ID_TAGTARGETS_TYPE,      EBML_STR,  0, offsetof(MatroskaTagTarget,type) },
 472     { MATROSKA_ID_TAGTARGETS_TYPEVALUE, EBML_UINT, 0, offsetof(MatroskaTagTarget,typevalue), {.u=50} },
 473     { MATROSKA_ID_TAGTARGETS_TRACKUID,  EBML_UINT, 0, offsetof(MatroskaTagTarget,trackuid) },
 474     { MATROSKA_ID_TAGTARGETS_CHAPTERUID,EBML_UINT, 0, offsetof(MatroskaTagTarget,chapteruid) },
 475     { MATROSKA_ID_TAGTARGETS_ATTACHUID, EBML_UINT, 0, offsetof(MatroskaTagTarget,attachuid) },
 476     { 0 }
 477 };
 478
 479 static EbmlSyntax matroska_tag[] = {
 480     { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTags,tag), {.n=matroska_simpletag} },
 481     { MATROSKA_ID_TAGTARGETS,         EBML_NEST, 0, offsetof(MatroskaTags,target), {.n=matroska_tagtargets} },
 482     { 0 }
 483 };
 484
 485 static EbmlSyntax matroska_tags[] = {
 486     { MATROSKA_ID_TAG,                EBML_NEST, sizeof(MatroskaTags), offsetof(MatroskaDemuxContext,tags), {.n=matroska_tag} },
 487     { 0 }
 488 };
 489
 490 static EbmlSyntax matroska_seekhead_entry[] = {
 491     { MATROSKA_ID_SEEKID,             EBML_UINT, 0, offsetof(MatroskaSeekhead,id) },
 492     { MATROSKA_ID_SEEKPOSITION,       EBML_UINT, 0, offsetof(MatroskaSeekhead,pos), {.u=-1} },
 493     { 0 }
 494 };
 495
 496 static EbmlSyntax matroska_seekhead[] = {
 497     { MATROSKA_ID_SEEKENTRY,          EBML_NEST, sizeof(MatroskaSeekhead), offsetof(MatroskaDemuxContext,seekhead), {.n=matroska_seekhead_entry} },
 498     { 0 }
 499 };
 500
 501 static EbmlSyntax matroska_segment[] = {
 502     { MATROSKA_ID_INFO,           EBML_NEST, 0, 0, {.n=matroska_info       } },
 503     { MATROSKA_ID_TRACKS,         EBML_NEST, 0, 0, {.n=matroska_tracks     } },
 504     { MATROSKA_ID_ATTACHMENTS,    EBML_NEST, 0, 0, {.n=matroska_attachments} },
 505     { MATROSKA_ID_CHAPTERS,       EBML_NEST, 0, 0, {.n=matroska_chapters   } },
 506     { MATROSKA_ID_CUES,           EBML_NEST, 0, 0, {.n=matroska_index      } },
 507     { MATROSKA_ID_TAGS,           EBML_NEST, 0, 0, {.n=matroska_tags       } },
 508     { MATROSKA_ID_SEEKHEAD,       EBML_NEST, 0, 0, {.n=matroska_seekhead   } },
 509     { MATROSKA_ID_CLUSTER,        EBML_STOP },
 510     { 0 }
 511 };
 512
 513 static EbmlSyntax matroska_segments[] = {
 514     { MATROSKA_ID_SEGMENT,        EBML_NEST, 0, 0, {.n=matroska_segment    } },
 515     { 0 }
 516 };
 517
 518 static EbmlSyntax matroska_blockgroup[] = {
 519     { MATROSKA_ID_BLOCK,          EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
 520     { MATROSKA_ID_SIMPLEBLOCK,    EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
 521     { MATROSKA_ID_BLOCKDURATION,  EBML_UINT, 0, offsetof(MatroskaBlock,duration) },
 522     { MATROSKA_ID_BLOCKREFERENCE, EBML_UINT, 0, offsetof(MatroskaBlock,reference) },
 523     { 1,                          EBML_UINT, 0, offsetof(MatroskaBlock,non_simple), {.u=1} },
 524     { 0 }
 525 };
 526
 527 static EbmlSyntax matroska_cluster[] = {
 528     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
 529     { MATROSKA_ID_BLOCKGROUP,     EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 530     { MATROSKA_ID_SIMPLEBLOCK,    EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 531     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
 532     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
 533     { 0 }
 534 };
 535
 536 static EbmlSyntax matroska_clusters[] = {
 537     { MATROSKA_ID_CLUSTER,        EBML_NEST, 0, 0, {.n=matroska_cluster} },
 538     { MATROSKA_ID_INFO,           EBML_NONE },
 539     { MATROSKA_ID_CUES,           EBML_NONE },
 540     { MATROSKA_ID_TAGS,           EBML_NONE },
 541     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
 542     { 0 }
 543 };
 544
 545 static const char *matroska_doctypes[] = { "matroska", "webm" };
 546
 547 static int matroska_resync(MatroskaDemuxContext *matroska, int64_t last_pos)
 548 {
 549     AVIOContext *pb = matroska->ctx->pb;
 550     uint32_t id;
 551     matroska->current_id = 0;
 552     matroska->num_levels = 0;
 553
 554     // seek to next position to resync from
 555     if (avio_seek(pb, last_pos + 1, SEEK_SET) < 0 || avio_tell(pb) <= last_pos)
 556         goto eof;
 557
 558     id = avio_rb32(pb);
 559
 560     // try to find a toplevel element
 561     while (!url_feof(pb)) {
 562         if (id == MATROSKA_ID_INFO || id == MATROSKA_ID_TRACKS ||
 563             id == MATROSKA_ID_CUES || id == MATROSKA_ID_TAGS ||
 564             id == MATROSKA_ID_SEEKHEAD || id == MATROSKA_ID_ATTACHMENTS ||
 565             id == MATROSKA_ID_CLUSTER || id == MATROSKA_ID_CHAPTERS)
 566         {
 567             matroska->current_id = id;
 568             return 0;
 569         }
 570         id = (id << 8) | avio_r8(pb);
 571     }
 572 eof:
 573     matroska->done = 1;
 574     return AVERROR_EOF;
 575 }
 576
 577 /*
 578  * Return: Whether we reached the end of a level in the hierarchy or not.
 579  */
 580 static int ebml_level_end(MatroskaDemuxContext *matroska)
 581 {
 582     AVIOContext *pb = matroska->ctx->pb;
 583     int64_t pos = avio_tell(pb);
 584
 585     if (matroska->num_levels > 0) {
 586         MatroskaLevel *level = &matroska->levels[matroska->num_levels - 1];
 587         if (pos - level->start >= level->length || matroska->current_id) {
 588             matroska->num_levels--;
 589             return 1;
 590         }
 591     }
 592     return 0;
 593 }
 594
 595 /*
 596  * Read: an "EBML number", which is defined as a variable-length
 597  * array of bytes. The first byte indicates the length by giving a
 598  * number of 0-bits followed by a one. The position of the first
 599  * "one" bit inside the first byte indicates the length of this
 600  * number.
 601  * Returns: number of bytes read, < 0 on error
 602  */
 603 static int ebml_read_num(MatroskaDemuxContext *matroska, AVIOContext *pb,
 604                          int max_size, uint64_t *number)
 605 {
 606     int read = 1, n = 1;
 607     uint64_t total = 0;
 608
 609     /* The first byte tells us the length in bytes - avio_r8() can normally
 610      * return 0, but since that's not a valid first ebmlID byte, we can
 611      * use it safely here to catch EOS. */
 612     if (!(total = avio_r8(pb))) {
 613         /* we might encounter EOS here */
 614         if (!url_feof(pb)) {
 615             int64_t pos = avio_tell(pb);
 616             av_log(matroska->ctx, AV_LOG_ERROR,
 617                    "Read error at pos. %"PRIu64" (0x%"PRIx64")\n",
 618                    pos, pos);
 619         }
 620         return AVERROR(EIO); /* EOS or actual I/O error */
 621     }
 622
 623     /* get the length of the EBML number */
 624     read = 8 - ff_log2_tab[total];
 625     if (read > max_size) {
 626         int64_t pos = avio_tell(pb) - 1;
 627         av_log(matroska->ctx, AV_LOG_ERROR,
 628                "Invalid EBML number size tag 0x%02x at pos %"PRIu64" (0x%"PRIx64")\n",
 629                (uint8_t) total, pos, pos);
 630         return AVERROR_INVALIDDATA;
 631     }
 632
 633     /* read out length */
 634     total ^= 1 << ff_log2_tab[total];
 635     while (n++ < read)
 636         total = (total << 8) | avio_r8(pb);
 637
 638     *number = total;
 639
 640     return read;
 641 }
 642
 643 /**
 644  * Read a EBML length value.
 645  * This needs special handling for the "unknown length" case which has multiple
 646  * encodings.
 647  */
 648 static int ebml_read_length(MatroskaDemuxContext *matroska, AVIOContext *pb,
 649                             uint64_t *number)
 650 {
 651     int res = ebml_read_num(matroska, pb, 8, number);
 652     if (res > 0 && *number + 1 == 1ULL << (7 * res))
 653         *number = 0xffffffffffffffULL;
 654     return res;
 655 }
 656
 657 /*
 658  * Read the next element as an unsigned int.
 659  * 0 is success, < 0 is failure.
 660  */
 661 static int ebml_read_uint(AVIOContext *pb, int size, uint64_t *num)
 662 {
 663     int n = 0;
 664
 665     if (size > 8)
 666         return AVERROR_INVALIDDATA;
 667
 668     /* big-endian ordering; build up number */
 669     *num = 0;
 670     while (n++ < size)
 671         *num = (*num << 8) | avio_r8(pb);
 672
 673     return 0;
 674 }
 675
 676 /*
 677  * Read the next element as a float.
 678  * 0 is success, < 0 is failure.
 679  */
 680 static int ebml_read_float(AVIOContext *pb, int size, double *num)
 681 {
 682     if (size == 0) {
 683         *num = 0;
 684     } else if (size == 4) {
 685         *num = av_int2float(avio_rb32(pb));
 686     } else if (size == 8){
 687         *num = av_int2double(avio_rb64(pb));
 688     } else
 689         return AVERROR_INVALIDDATA;
 690
 691     return 0;
 692 }
 693
 694 /*
 695  * Read the next element as an ASCII string.
 696  * 0 is success, < 0 is failure.
 697  */
 698 static int ebml_read_ascii(AVIOContext *pb, int size, char **str)
 699 {
 700     av_free(*str);
 701     /* EBML strings are usually not 0-terminated, so we allocate one
 702      * byte more, read the string and NULL-terminate it ourselves. */
 703     if (!(*str = av_malloc(size + 1)))
 704         return AVERROR(ENOMEM);
 705     if (avio_read(pb, (uint8_t *) *str, size) != size) {
 706         av_freep(str);
 707         return AVERROR(EIO);
 708     }
 709     (*str)[size] = '\0';
 710
 711     return 0;
 712 }
 713
 714 /*
 715  * Read the next element as binary data.
 716  * 0 is success, < 0 is failure.
 717  */
 718 static int ebml_read_binary(AVIOContext *pb, int length, EbmlBin *bin)
 719 {
 720     av_free(bin->data);
 721     if (!(bin->data = av_malloc(length)))
 722         return AVERROR(ENOMEM);
 723
 724     bin->size = length;
 725     bin->pos  = avio_tell(pb);
 726     if (avio_read(pb, bin->data, length) != length) {
 727         av_freep(&bin->data);
 728         return AVERROR(EIO);
 729     }
 730
 731     return 0;
 732 }
 733
 734 /*
 735  * Read the next element, but only the header. The contents
 736  * are supposed to be sub-elements which can be read separately.
 737  * 0 is success, < 0 is failure.
 738  */
 739 static int ebml_read_master(MatroskaDemuxContext *matroska, uint64_t length)
 740 {
 741     AVIOContext *pb = matroska->ctx->pb;
 742     MatroskaLevel *level;
 743
 744     if (matroska->num_levels >= EBML_MAX_DEPTH) {
 745         av_log(matroska->ctx, AV_LOG_ERROR,
 746                "File moves beyond max. allowed depth (%d)\n", EBML_MAX_DEPTH);
 747         return AVERROR(ENOSYS);
 748     }
 749
 750     level = &matroska->levels[matroska->num_levels++];
 751     level->start = avio_tell(pb);
 752     level->length = length;
 753
 754     return 0;
 755 }
 756
 757 /*
 758  * Read signed/unsigned "EBML" numbers.
 759  * Return: number of bytes processed, < 0 on error
 760  */
 761 static int matroska_ebmlnum_uint(MatroskaDemuxContext *matroska,
 762                                  uint8_t *data, uint32_t size, uint64_t *num)
 763 {
 764     AVIOContext pb;
 765     ffio_init_context(&pb, data, size, 0, NULL, NULL, NULL, NULL);
 766     return ebml_read_num(matroska, &pb, FFMIN(size, 8), num);
 767 }
 768
 769 /*
 770  * Same as above, but signed.
 771  */
 772 static int matroska_ebmlnum_sint(MatroskaDemuxContext *matroska,
 773                                  uint8_t *data, uint32_t size, int64_t *num)
 774 {
 775     uint64_t unum;
 776     int res;
 777
 778     /* read as unsigned number first */
 779     if ((res = matroska_ebmlnum_uint(matroska, data, size, &unum)) < 0)
 780         return res;
 781
 782     /* make signed (weird way) */
 783     *num = unum - ((1LL << (7*res - 1)) - 1);
 784
 785     return res;
 786 }
 787
 788 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
 789                            EbmlSyntax *syntax, void *data);
 790
 791 static int ebml_parse_id(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 792                          uint32_t id, void *data)
 793 {
 794     int i;
 795     for (i=0; syntax[i].id; i++)
 796         if (id == syntax[i].id)
 797             break;
 798     if (!syntax[i].id && id == MATROSKA_ID_CLUSTER &&
 799         matroska->num_levels > 0 &&
 800         matroska->levels[matroska->num_levels-1].length == 0xffffffffffffff)
 801         return 0;  // we reached the end of an unknown size cluster
 802     if (!syntax[i].id && id != EBML_ID_VOID && id != EBML_ID_CRC32)
 803         av_log(matroska->ctx, AV_LOG_INFO, "Unknown entry 0x%X\n", id);
 804     return ebml_parse_elem(matroska, &syntax[i], data);
 805 }
 806
 807 static int ebml_parse(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 808                       void *data)
 809 {
 810     if (!matroska->current_id) {
 811         uint64_t id;
 812         int res = ebml_read_num(matroska, matroska->ctx->pb, 4, &id);
 813         if (res < 0)
 814             return res;
 815         matroska->current_id = id | 1 << 7*res;
 816     }
 817     return ebml_parse_id(matroska, syntax, matroska->current_id, data);
 818 }
 819
 820 static int ebml_parse_nest(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 821                            void *data)
 822 {
 823     int i, res = 0;
 824
 825     for (i=0; syntax[i].id; i++)
 826         switch (syntax[i].type) {
 827         case EBML_UINT:
 828             *(uint64_t *)((char *)data+syntax[i].data_offset) = syntax[i].def.u;
 829             break;
 830         case EBML_FLOAT:
 831             *(double   *)((char *)data+syntax[i].data_offset) = syntax[i].def.f;
 832             break;
 833         case EBML_STR:
 834         case EBML_UTF8:
 835             *(char    **)((char *)data+syntax[i].data_offset) = av_strdup(syntax[i].def.s);
 836             break;
 837         }
 838
 839     while (!res && !ebml_level_end(matroska))
 840         res = ebml_parse(matroska, syntax, data);
 841
 842     return res;
 843 }
 844
 845 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
 846                            EbmlSyntax *syntax, void *data)
 847 {
 848     static const uint64_t max_lengths[EBML_TYPE_COUNT] = {
 849         [EBML_UINT]  = 8,
 850         [EBML_FLOAT] = 8,
 851         // max. 16 MB for strings
 852         [EBML_STR]   = 0x1000000,
 853         [EBML_UTF8]  = 0x1000000,
 854         // max. 256 MB for binary data
 855         [EBML_BIN]   = 0x10000000,
 856         // no limits for anything else
 857     };
 858     AVIOContext *pb = matroska->ctx->pb;
 859     uint32_t id = syntax->id;
 860     uint64_t length;
 861     int res;
 862     void *newelem;
 863
 864     data = (char *)data + syntax->data_offset;
 865     if (syntax->list_elem_size) {
 866         EbmlList *list = data;
 867         newelem = av_realloc(list->elem, (list->nb_elem+1)*syntax->list_elem_size);
 868         if (!newelem)
 869             return AVERROR(ENOMEM);
 870         list->elem = newelem;
 871         data = (char*)list->elem + list->nb_elem*syntax->list_elem_size;
 872         memset(data, 0, syntax->list_elem_size);
 873         list->nb_elem++;
 874     }
 875
 876     if (syntax->type != EBML_PASS && syntax->type != EBML_STOP) {
 877         matroska->current_id = 0;
 878         if ((res = ebml_read_length(matroska, pb, &length)) < 0)
 879             return res;
 880         if (max_lengths[syntax->type] && length > max_lengths[syntax->type]) {
 881             av_log(matroska->ctx, AV_LOG_ERROR,
 882                    "Invalid length 0x%"PRIx64" > 0x%"PRIx64" for syntax element %i\n",
 883                    length, max_lengths[syntax->type], syntax->type);
 884             return AVERROR_INVALIDDATA;
 885         }
 886     }
 887
 888     switch (syntax->type) {
 889     case EBML_UINT:  res = ebml_read_uint  (pb, length, data);  break;
 890     case EBML_FLOAT: res = ebml_read_float (pb, length, data);  break;
 891     case EBML_STR:
 892     case EBML_UTF8:  res = ebml_read_ascii (pb, length, data);  break;
 893     case EBML_BIN:   res = ebml_read_binary(pb, length, data);  break;
 894     case EBML_NEST:  if ((res=ebml_read_master(matroska, length)) < 0)
 895                          return res;
 896                      if (id == MATROSKA_ID_SEGMENT)
 897                          matroska->segment_start = avio_tell(matroska->ctx->pb);
 898                      return ebml_parse_nest(matroska, syntax->def.n, data);
 899     case EBML_PASS:  return ebml_parse_id(matroska, syntax->def.n, id, data);
 900     case EBML_STOP:  return 1;
 901     default:         return avio_skip(pb,length)<0 ? AVERROR(EIO) : 0;
 902     }
 903     if (res == AVERROR_INVALIDDATA)
 904         av_log(matroska->ctx, AV_LOG_ERROR, "Invalid element\n");
 905     else if (res == AVERROR(EIO))
 906         av_log(matroska->ctx, AV_LOG_ERROR, "Read error\n");
 907     return res;
 908 }
 909
 910 static void ebml_free(EbmlSyntax *syntax, void *data)
 911 {
 912     int i, j;
 913     for (i=0; syntax[i].id; i++) {
 914         void *data_off = (char *)data + syntax[i].data_offset;
 915         switch (syntax[i].type) {
 916         case EBML_STR:
 917         case EBML_UTF8:  av_freep(data_off);                      break;
 918         case EBML_BIN:   av_freep(&((EbmlBin *)data_off)->data);  break;
 919         case EBML_NEST:
 920             if (syntax[i].list_elem_size) {
 921                 EbmlList *list = data_off;
 922                 char *ptr = list->elem;
 923                 for (j=0; j<list->nb_elem; j++, ptr+=syntax[i].list_elem_size)
 924                     ebml_free(syntax[i].def.n, ptr);
 925                 av_free(list->elem);
 926             } else
 927                 ebml_free(syntax[i].def.n, data_off);
 928         default:  break;
 929         }
 930     }
 931 }
 932
 933
 934 /*
 935  * Autodetecting...
 936  */
 937 static int matroska_probe(AVProbeData *p)
 938 {
 939     uint64_t total = 0;
 940     int len_mask = 0x80, size = 1, n = 1, i;
 941
 942     /* EBML header? */
 943     if (AV_RB32(p->buf) != EBML_ID_HEADER)
 944         return 0;
 945
 946     /* length of header */
 947     total = p->buf[4];
 948     while (size <= 8 && !(total & len_mask)) {
 949         size++;
 950         len_mask >>= 1;
 951     }
 952     if (size > 8)
 953       return 0;
 954     total &= (len_mask - 1);
 955     while (n < size)
 956         total = (total << 8) | p->buf[4 + n++];
 957
 958     /* Does the probe data contain the whole header? */
 959     if (p->buf_size < 4 + size + total)
 960       return 0;
 961
 962     /* The header should contain a known document type. For now,
 963      * we don't parse the whole header but simply check for the
 964      * availability of that array of characters inside the header.
 965      * Not fully fool-proof, but good enough. */
 966     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++) {
 967         int probelen = strlen(matroska_doctypes[i]);
 968         if (total < probelen)
 969             continue;
 970         for (n = 4+size; n <= 4+size+total-probelen; n++)
 971             if (!memcmp(p->buf+n, matroska_doctypes[i], probelen))
 972                 return AVPROBE_SCORE_MAX;
 973     }
 974
 975     // probably valid EBML header but no recognized doctype
 976     return AVPROBE_SCORE_MAX/2;
 977 }
 978
 979 static MatroskaTrack *matroska_find_track_by_num(MatroskaDemuxContext *matroska,
 980                                                  int num)
 981 {
 982     MatroskaTrack *tracks = matroska->tracks.elem;
 983     int i;
 984
 985     for (i=0; i < matroska->tracks.nb_elem; i++)
 986         if (tracks[i].num == num)
 987             return &tracks[i];
 988
 989     av_log(matroska->ctx, AV_LOG_ERROR, "Invalid track number %d\n", num);
 990     return NULL;
 991 }
 992
 993 static int matroska_decode_buffer(uint8_t** buf, int* buf_size,
 994                                   MatroskaTrack *track)
 995 {
 996     MatroskaTrackEncoding *encodings = track->encodings.elem;
 997     uint8_t* data = *buf;
 998     int isize = *buf_size;
 999     uint8_t* pkt_data = NULL;
1000     uint8_t av_unused *newpktdata;
1001     int pkt_size = isize;
1002     int result = 0;
1003     int olen;
1004
1005     if (pkt_size >= 10000000)
1006         return -1;
1007
1008     switch (encodings[0].compression.algo) {
1009     case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP:
1010         return encodings[0].compression.settings.size;
1011     case MATROSKA_TRACK_ENCODING_COMP_LZO:
1012         do {
1013             olen = pkt_size *= 3;
1014             pkt_data = av_realloc(pkt_data, pkt_size+AV_LZO_OUTPUT_PADDING);
1015             result = av_lzo1x_decode(pkt_data, &olen, data, &isize);
1016         } while (result==AV_LZO_OUTPUT_FULL && pkt_size<10000000);
1017         if (result)
1018             goto failed;
1019         pkt_size -= olen;
1020         break;
1021 #if CONFIG_ZLIB
1022     case MATROSKA_TRACK_ENCODING_COMP_ZLIB: {
1023         z_stream zstream = {0};
1024         if (inflateInit(&zstream) != Z_OK)
1025             return -1;
1026         zstream.next_in = data;
1027         zstream.avail_in = isize;
1028         do {
1029             pkt_size *= 3;
1030             newpktdata = av_realloc(pkt_data, pkt_size);
1031             if (!newpktdata) {
1032                 inflateEnd(&zstream);
1033                 goto failed;
1034             }
1035             pkt_data = newpktdata;
1036             zstream.avail_out = pkt_size - zstream.total_out;
1037             zstream.next_out = pkt_data + zstream.total_out;
1038             if (pkt_data) {
1039                 result = inflate(&zstream, Z_NO_FLUSH);
1040             } else
1041                 result = Z_MEM_ERROR;
1042         } while (result==Z_OK && pkt_size<10000000);
1043         pkt_size = zstream.total_out;
1044         inflateEnd(&zstream);
1045         if (result != Z_STREAM_END)
1046             goto failed;
1047         break;
1048     }
1049 #endif
1050 #if CONFIG_BZLIB
1051     case MATROSKA_TRACK_ENCODING_COMP_BZLIB: {
1052         bz_stream bzstream = {0};
1053         if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
1054             return -1;
1055         bzstream.next_in = data;
1056         bzstream.avail_in = isize;
1057         do {
1058             pkt_size *= 3;
1059             newpktdata = av_realloc(pkt_data, pkt_size);
1060             if (!newpktdata) {
1061                 BZ2_bzDecompressEnd(&bzstream);
1062                 goto failed;
1063             }
1064             pkt_data = newpktdata;
1065             bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
1066             bzstream.next_out = pkt_data + bzstream.total_out_lo32;
1067             if (pkt_data) {
1068                 result = BZ2_bzDecompress(&bzstream);
1069             } else
1070                 result = BZ_MEM_ERROR;
1071         } while (result==BZ_OK && pkt_size<10000000);
1072         pkt_size = bzstream.total_out_lo32;
1073         BZ2_bzDecompressEnd(&bzstream);
1074         if (result != BZ_STREAM_END)
1075             goto failed;
1076         break;
1077     }
1078 #endif
1079     default:
1080         return -1;
1081     }
1082
1083     *buf = pkt_data;
1084     *buf_size = pkt_size;
1085     return 0;
1086  failed:
1087     av_free(pkt_data);
1088     return -1;
1089 }
1090
1091 static void matroska_fix_ass_packet(MatroskaDemuxContext *matroska,
1092                                     AVPacket *pkt, uint64_t display_duration)
1093 {
1094     char *line, *layer, *ptr = pkt->data, *end = ptr+pkt->size;
1095     for (; *ptr!=',' && ptr<end-1; ptr++);
1096     if (*ptr == ',')
1097         ptr++;
1098     layer = ptr;
1099     for (; *ptr!=',' && ptr<end-1; ptr++);
1100     if (*ptr == ',') {
1101         int64_t end_pts = pkt->pts + display_duration;
1102         int sc = matroska->time_scale * pkt->pts / 10000000;
1103         int ec = matroska->time_scale * end_pts  / 10000000;
1104         int sh, sm, ss, eh, em, es, len;
1105         sh = sc/360000;  sc -= 360000*sh;
1106         sm = sc/  6000;  sc -=   6000*sm;
1107         ss = sc/   100;  sc -=    100*ss;
1108         eh = ec/360000;  ec -= 360000*eh;
1109         em = ec/  6000;  ec -=   6000*em;
1110         es = ec/   100;  ec -=    100*es;
1111         *ptr++ = '\0';
1112         len = 50 + end-ptr + FF_INPUT_BUFFER_PADDING_SIZE;
1113         if (!(line = av_malloc(len)))
1114             return;
1115         snprintf(line,len,"Dialogue: %s,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s\r\n",
1116                  layer, sh, sm, ss, sc, eh, em, es, ec, ptr);
1117         av_free(pkt->data);
1118         pkt->data = line;
1119         pkt->size = strlen(line);
1120     }
1121 }
1122
1123 static int matroska_merge_packets(AVPacket *out, AVPacket *in)
1124 {
1125     void *newdata = av_realloc(out->data, out->size+in->size);
1126     if (!newdata)
1127         return AVERROR(ENOMEM);
1128     out->data = newdata;
1129     memcpy(out->data+out->size, in->data, in->size);
1130     out->size += in->size;
1131     av_destruct_packet(in);
1132     av_free(in);
1133     return 0;
1134 }
1135
1136 static void matroska_convert_tag(AVFormatContext *s, EbmlList *list,
1137                                  AVDictionary **metadata, char *prefix)
1138 {
1139     MatroskaTag *tags = list->elem;
1140     char key[1024];
1141     int i;
1142
1143     for (i=0; i < list->nb_elem; i++) {
1144         const char *lang = strcmp(tags[i].lang, "und") ? tags[i].lang : NULL;
1145
1146         if (!tags[i].name) {
1147             av_log(s, AV_LOG_WARNING, "Skipping invalid tag with no TagName.\n");
1148             continue;
1149         }
1150         if (prefix)  snprintf(key, sizeof(key), "%s/%s", prefix, tags[i].name);
1151         else         av_strlcpy(key, tags[i].name, sizeof(key));
1152         if (tags[i].def || !lang) {
1153         av_dict_set(metadata, key, tags[i].string, 0);
1154         if (tags[i].sub.nb_elem)
1155             matroska_convert_tag(s, &tags[i].sub, metadata, key);
1156         }
1157         if (lang) {
1158             av_strlcat(key, "-", sizeof(key));
1159             av_strlcat(key, lang, sizeof(key));
1160             av_dict_set(metadata, key, tags[i].string, 0);
1161             if (tags[i].sub.nb_elem)
1162                 matroska_convert_tag(s, &tags[i].sub, metadata, key);
1163         }
1164     }
1165     ff_metadata_conv(metadata, NULL, ff_mkv_metadata_conv);
1166 }
1167
1168 static void matroska_convert_tags(AVFormatContext *s)
1169 {
1170     MatroskaDemuxContext *matroska = s->priv_data;
1171     MatroskaTags *tags = matroska->tags.elem;
1172     int i, j;
1173
1174     for (i=0; i < matroska->tags.nb_elem; i++) {
1175         if (tags[i].target.attachuid) {
1176             MatroskaAttachement *attachment = matroska->attachments.elem;
1177             for (j=0; j<matroska->attachments.nb_elem; j++)
1178                 if (attachment[j].uid == tags[i].target.attachuid
1179                     && attachment[j].stream)
1180                     matroska_convert_tag(s, &tags[i].tag,
1181                                          &attachment[j].stream->metadata, NULL);
1182         } else if (tags[i].target.chapteruid) {
1183             MatroskaChapter *chapter = matroska->chapters.elem;
1184             for (j=0; j<matroska->chapters.nb_elem; j++)
1185                 if (chapter[j].uid == tags[i].target.chapteruid
1186                     && chapter[j].chapter)
1187                     matroska_convert_tag(s, &tags[i].tag,
1188                                          &chapter[j].chapter->metadata, NULL);
1189         } else if (tags[i].target.trackuid) {
1190             MatroskaTrack *track = matroska->tracks.elem;
1191             for (j=0; j<matroska->tracks.nb_elem; j++)
1192                 if (track[j].uid == tags[i].target.trackuid && track[j].stream)
1193                     matroska_convert_tag(s, &tags[i].tag,
1194                                          &track[j].stream->metadata, NULL);
1195         } else {
1196             matroska_convert_tag(s, &tags[i].tag, &s->metadata,
1197                                  tags[i].target.type);
1198         }
1199     }
1200 }
1201
1202 static int matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska, int idx)
1203 {
1204     EbmlList *seekhead_list = &matroska->seekhead;
1205     MatroskaSeekhead *seekhead = seekhead_list->elem;
1206     uint32_t level_up = matroska->level_up;
1207     int64_t before_pos = avio_tell(matroska->ctx->pb);
1208     uint32_t saved_id = matroska->current_id;
1209     MatroskaLevel level;
1210     int64_t offset;
1211     int ret = 0;
1212
1213     if (idx >= seekhead_list->nb_elem
1214             || seekhead[idx].id == MATROSKA_ID_SEEKHEAD
1215             || seekhead[idx].id == MATROSKA_ID_CLUSTER)
1216         return 0;
1217
1218     /* seek */
1219     offset = seekhead[idx].pos + matroska->segment_start;
1220     if (avio_seek(matroska->ctx->pb, offset, SEEK_SET) == offset) {
1221         /* We don't want to lose our seekhead level, so we add
1222          * a dummy. This is a crude hack. */
1223         if (matroska->num_levels == EBML_MAX_DEPTH) {
1224             av_log(matroska->ctx, AV_LOG_INFO,
1225                    "Max EBML element depth (%d) reached, "
1226                    "cannot parse further.\n", EBML_MAX_DEPTH);
1227             ret = AVERROR_INVALIDDATA;
1228         } else {
1229             level.start = 0;
1230             level.length = (uint64_t)-1;
1231             matroska->levels[matroska->num_levels] = level;
1232             matroska->num_levels++;
1233             matroska->current_id = 0;
1234
1235             ret = ebml_parse(matroska, matroska_segment, matroska);
1236
1237             /* remove dummy level */
1238             while (matroska->num_levels) {
1239                 uint64_t length = matroska->levels[--matroska->num_levels].length;
1240                 if (length == (uint64_t)-1)
1241                     break;
1242             }
1243         }
1244     }
1245     /* seek back */
1246     avio_seek(matroska->ctx->pb, before_pos, SEEK_SET);
1247     matroska->level_up = level_up;
1248     matroska->current_id = saved_id;
1249
1250     return ret;
1251 }
1252
1253 static void matroska_execute_seekhead(MatroskaDemuxContext *matroska)
1254 {
1255     EbmlList *seekhead_list = &matroska->seekhead;
1256     int64_t before_pos = avio_tell(matroska->ctx->pb);
1257     int i;
1258
1259     // we should not do any seeking in the streaming case
1260     if (!matroska->ctx->pb->seekable ||
1261         (matroska->ctx->flags & AVFMT_FLAG_IGNIDX))
1262         return;
1263
1264     for (i = 0; i < seekhead_list->nb_elem; i++) {
1265         MatroskaSeekhead *seekhead = seekhead_list->elem;
1266         if (seekhead[i].pos <= before_pos)
1267             continue;
1268
1269         // defer cues parsing until we actually need cue data.
1270         if (seekhead[i].id == MATROSKA_ID_CUES) {
1271             matroska->cues_parsing_deferred = 1;
1272             continue;
1273         }
1274
1275         if (matroska_parse_seekhead_entry(matroska, i) < 0) {
1276             // mark index as broken
1277             matroska->cues_parsing_deferred = -1;
1278             break;
1279         }
1280     }
1281 }
1282
1283 static void matroska_add_index_entries(MatroskaDemuxContext *matroska) {
1284     EbmlList *index_list;
1285     MatroskaIndex *index;
1286     int index_scale = 1;
1287     int i, j;
1288
1289     index_list = &matroska->index;
1290     index = index_list->elem;
1291     if (index_list->nb_elem
1292         && index[0].time > 1E14/matroska->time_scale) {
1293         av_log(matroska->ctx, AV_LOG_WARNING, "Working around broken index.\n");
1294         index_scale = matroska->time_scale;
1295     }
1296     for (i = 0; i < index_list->nb_elem; i++) {
1297         EbmlList *pos_list = &index[i].pos;
1298         MatroskaIndexPos *pos = pos_list->elem;
1299         for (j = 0; j < pos_list->nb_elem; j++) {
1300             MatroskaTrack *track = matroska_find_track_by_num(matroska, pos[j].track);
1301             if (track && track->stream)
1302                 av_add_index_entry(track->stream,
1303                                    pos[j].pos + matroska->segment_start,
1304                                    index[i].time/index_scale, 0, 0,
1305                                    AVINDEX_KEYFRAME);
1306         }
1307     }
1308 }
1309
1310 static void matroska_parse_cues(MatroskaDemuxContext *matroska) {
1311     EbmlList *seekhead_list = &matroska->seekhead;
1312     MatroskaSeekhead *seekhead = seekhead_list->elem;
1313     int i;
1314
1315     for (i = 0; i < seekhead_list->nb_elem; i++)
1316         if (seekhead[i].id == MATROSKA_ID_CUES)
1317             break;
1318     assert(i <= seekhead_list->nb_elem);
1319
1320     if (matroska_parse_seekhead_entry(matroska, i) < 0)
1321        matroska->cues_parsing_deferred = -1;
1322     matroska_add_index_entries(matroska);
1323 }
1324
1325 static int matroska_aac_profile(char *codec_id)
1326 {
1327     static const char * const aac_profiles[] = { "MAIN", "LC", "SSR" };
1328     int profile;
1329
1330     for (profile=0; profile<FF_ARRAY_ELEMS(aac_profiles); profile++)
1331         if (strstr(codec_id, aac_profiles[profile]))
1332             break;
1333     return profile + 1;
1334 }
1335
1336 static int matroska_aac_sri(int samplerate)
1337 {
1338     int sri;
1339
1340     for (sri=0; sri<FF_ARRAY_ELEMS(avpriv_mpeg4audio_sample_rates); sri++)
1341         if (avpriv_mpeg4audio_sample_rates[sri] == samplerate)
1342             break;
1343     return sri;
1344 }
1345
1346 static int matroska_read_header(AVFormatContext *s)
1347 {
1348     MatroskaDemuxContext *matroska = s->priv_data;
1349     EbmlList *attachements_list = &matroska->attachments;
1350     MatroskaAttachement *attachements;
1351     EbmlList *chapters_list = &matroska->chapters;
1352     MatroskaChapter *chapters;
1353     MatroskaTrack *tracks;
1354     uint64_t max_start = 0;
1355     int64_t pos;
1356     Ebml ebml = { 0 };
1357     AVStream *st;
1358     int i, j, k, res;
1359
1360     matroska->ctx = s;
1361
1362     /* First read the EBML header. */
1363     if (ebml_parse(matroska, ebml_syntax, &ebml)
1364         || ebml.version > EBML_VERSION       || ebml.max_size > sizeof(uint64_t)
1365         || ebml.id_length > sizeof(uint32_t) || ebml.doctype_version > 3) {
1366         av_log(matroska->ctx, AV_LOG_ERROR,
1367                "EBML header using unsupported features\n"
1368                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
1369                ebml.version, ebml.doctype, ebml.doctype_version);
1370         ebml_free(ebml_syntax, &ebml);
1371         return AVERROR_PATCHWELCOME;
1372     } else if (ebml.doctype_version == 3) {
1373         av_log(matroska->ctx, AV_LOG_WARNING,
1374                "EBML header using unsupported features\n"
1375                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
1376                ebml.version, ebml.doctype, ebml.doctype_version);
1377     }
1378     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++)
1379         if (!strcmp(ebml.doctype, matroska_doctypes[i]))
1380             break;
1381     if (i >= FF_ARRAY_ELEMS(matroska_doctypes)) {
1382         av_log(s, AV_LOG_WARNING, "Unknown EBML doctype '%s'\n", ebml.doctype);
1383     }
1384     ebml_free(ebml_syntax, &ebml);
1385
1386     /* The next thing is a segment. */
1387     pos = avio_tell(matroska->ctx->pb);
1388     res = ebml_parse(matroska, matroska_segments, matroska);
1389     // try resyncing until we find a EBML_STOP type element.
1390     while (res != 1) {
1391         res = matroska_resync(matroska, pos);
1392         if (res < 0)
1393             return res;
1394         pos = avio_tell(matroska->ctx->pb);
1395         res = ebml_parse(matroska, matroska_segment, matroska);
1396     }
1397     matroska_execute_seekhead(matroska);
1398
1399     if (!matroska->time_scale)
1400         matroska->time_scale = 1000000;
1401     if (matroska->duration)
1402         matroska->ctx->duration = matroska->duration * matroska->time_scale
1403                                   * 1000 / AV_TIME_BASE;
1404     av_dict_set(&s->metadata, "title", matroska->title, 0);
1405
1406     tracks = matroska->tracks.elem;
1407     for (i=0; i < matroska->tracks.nb_elem; i++) {
1408         MatroskaTrack *track = &tracks[i];
1409         enum CodecID codec_id = CODEC_ID_NONE;
1410         EbmlList *encodings_list = &track->encodings;
1411         MatroskaTrackEncoding *encodings = encodings_list->elem;
1412         uint8_t *extradata = NULL;
1413         int extradata_size = 0;
1414         int extradata_offset = 0;
1415         uint32_t fourcc = 0;
1416         AVIOContext b;
1417
1418         /* Apply some sanity checks. */
1419         if (track->type != MATROSKA_TRACK_TYPE_VIDEO &&
1420             track->type != MATROSKA_TRACK_TYPE_AUDIO &&
1421             track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
1422             av_log(matroska->ctx, AV_LOG_INFO,
1423                    "Unknown or unsupported track type %"PRIu64"\n",
1424                    track->type);
1425             continue;
1426         }
1427         if (track->codec_id == NULL)
1428             continue;
1429
1430         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1431             if (!track->default_duration)
1432                 track->default_duration = 1000000000/track->video.frame_rate;
1433             if (!track->video.display_width)
1434                 track->video.display_width = track->video.pixel_width;
1435             if (!track->video.display_height)
1436                 track->video.display_height = track->video.pixel_height;
1437             if (track->video.color_space.size == 4)
1438                 fourcc = AV_RL32(track->video.color_space.data);
1439         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1440             if (!track->audio.out_samplerate)
1441                 track->audio.out_samplerate = track->audio.samplerate;
1442         }
1443         if (encodings_list->nb_elem > 1) {
1444             av_log(matroska->ctx, AV_LOG_ERROR,
1445                    "Multiple combined encodings not supported");
1446         } else if (encodings_list->nb_elem == 1) {
1447             if (encodings[0].type ||
1448                 (encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP &&
1449 #if CONFIG_ZLIB
1450                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_ZLIB &&
1451 #endif
1452 #if CONFIG_BZLIB
1453                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_BZLIB &&
1454 #endif
1455                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_LZO)) {
1456                 encodings[0].scope = 0;
1457                 av_log(matroska->ctx, AV_LOG_ERROR,
1458                        "Unsupported encoding type");
1459             } else if (track->codec_priv.size && encodings[0].scope&2) {
1460                 uint8_t *codec_priv = track->codec_priv.data;
1461                 int offset = matroska_decode_buffer(&track->codec_priv.data,
1462                                                     &track->codec_priv.size,
1463                                                     track);
1464                 if (offset < 0) {
1465                     track->codec_priv.data = NULL;
1466                     track->codec_priv.size = 0;
1467                     av_log(matroska->ctx, AV_LOG_ERROR,
1468                            "Failed to decode codec private data\n");
1469                 } else if (offset > 0) {
1470                     track->codec_priv.data = av_malloc(track->codec_priv.size + offset);
1471                     memcpy(track->codec_priv.data,
1472                            encodings[0].compression.settings.data, offset);
1473                     memcpy(track->codec_priv.data+offset, codec_priv,
1474                            track->codec_priv.size);
1475                     track->codec_priv.size += offset;
1476                 }
1477                 if (codec_priv != track->codec_priv.data)
1478                     av_free(codec_priv);
1479             }
1480         }
1481
1482         for(j=0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++){
1483             if(!strncmp(ff_mkv_codec_tags[j].str, track->codec_id,
1484                         strlen(ff_mkv_codec_tags[j].str))){
1485                 codec_id= ff_mkv_codec_tags[j].id;
1486                 break;
1487             }
1488         }
1489
1490         st = track->stream = avformat_new_stream(s, NULL);
1491         if (st == NULL)
1492             return AVERROR(ENOMEM);
1493
1494         if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC")
1495             && track->codec_priv.size >= 40
1496             && track->codec_priv.data != NULL) {
1497             track->ms_compat = 1;
1498             fourcc = AV_RL32(track->codec_priv.data + 16);
1499             codec_id = ff_codec_get_id(ff_codec_bmp_tags, fourcc);
1500             extradata_offset = 40;
1501         } else if (!strcmp(track->codec_id, "A_MS/ACM")
1502                    && track->codec_priv.size >= 14
1503                    && track->codec_priv.data != NULL) {
1504             int ret;
1505             ffio_init_context(&b, track->codec_priv.data, track->codec_priv.size,
1506                           AVIO_FLAG_READ, NULL, NULL, NULL, NULL);
1507             ret = ff_get_wav_header(&b, st->codec, track->codec_priv.size);
1508             if (ret < 0)
1509                 return ret;
1510             codec_id = st->codec->codec_id;
1511             extradata_offset = FFMIN(track->codec_priv.size, 18);
1512         } else if (!strcmp(track->codec_id, "V_QUICKTIME")
1513                    && (track->codec_priv.size >= 86)
1514                    && (track->codec_priv.data != NULL)) {
1515             fourcc = AV_RL32(track->codec_priv.data);
1516             codec_id = ff_codec_get_id(ff_codec_movvideo_tags, fourcc);
1517         } else if (codec_id == CODEC_ID_PCM_S16BE) {
1518             switch (track->audio.bitdepth) {
1519             case  8:  codec_id = CODEC_ID_PCM_U8;     break;
1520             case 24:  codec_id = CODEC_ID_PCM_S24BE;  break;
1521             case 32:  codec_id = CODEC_ID_PCM_S32BE;  break;
1522             }
1523         } else if (codec_id == CODEC_ID_PCM_S16LE) {
1524             switch (track->audio.bitdepth) {
1525             case  8:  codec_id = CODEC_ID_PCM_U8;     break;
1526             case 24:  codec_id = CODEC_ID_PCM_S24LE;  break;
1527             case 32:  codec_id = CODEC_ID_PCM_S32LE;  break;
1528             }
1529         } else if (codec_id==CODEC_ID_PCM_F32LE && track->audio.bitdepth==64) {
1530             codec_id = CODEC_ID_PCM_F64LE;
1531         } else if (codec_id == CODEC_ID_AAC && !track->codec_priv.size) {
1532             int profile = matroska_aac_profile(track->codec_id);
1533             int sri = matroska_aac_sri(track->audio.samplerate);
1534             extradata = av_mallocz(5 + FF_INPUT_BUFFER_PADDING_SIZE);
1535             if (extradata == NULL)
1536                 return AVERROR(ENOMEM);
1537             extradata[0] = (profile << 3) | ((sri&0x0E) >> 1);
1538             extradata[1] = ((sri&0x01) << 7) | (track->audio.channels<<3);
1539             if (strstr(track->codec_id, "SBR")) {
1540                 sri = matroska_aac_sri(track->audio.out_samplerate);
1541                 extradata[2] = 0x56;
1542                 extradata[3] = 0xE5;
1543                 extradata[4] = 0x80 | (sri<<3);
1544                 extradata_size = 5;
1545             } else
1546                 extradata_size = 2;
1547         } else if (codec_id == CODEC_ID_TTA) {
1548             extradata_size = 30;
1549             extradata = av_mallocz(extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
1550             if (extradata == NULL)
1551                 return AVERROR(ENOMEM);
1552             ffio_init_context(&b, extradata, extradata_size, 1,
1553                           NULL, NULL, NULL, NULL);
1554             avio_write(&b, "TTA1", 4);
1555             avio_wl16(&b, 1);
1556             avio_wl16(&b, track->audio.channels);
1557             avio_wl16(&b, track->audio.bitdepth);
1558             avio_wl32(&b, track->audio.out_samplerate);
1559             avio_wl32(&b, matroska->ctx->duration * track->audio.out_samplerate);
1560         } else if (codec_id == CODEC_ID_RV10 || codec_id == CODEC_ID_RV20 ||
1561                    codec_id == CODEC_ID_RV30 || codec_id == CODEC_ID_RV40) {
1562             extradata_offset = 26;
1563         } else if (codec_id == CODEC_ID_RA_144) {
1564             track->audio.out_samplerate = 8000;
1565             track->audio.channels = 1;
1566         } else if (codec_id == CODEC_ID_RA_288 || codec_id == CODEC_ID_COOK ||
1567                    codec_id == CODEC_ID_ATRAC3 || codec_id == CODEC_ID_SIPR) {
1568             int flavor;
1569             ffio_init_context(&b, track->codec_priv.data,track->codec_priv.size,
1570                           0, NULL, NULL, NULL, NULL);
1571             avio_skip(&b, 22);
1572             flavor                       = avio_rb16(&b);
1573             track->audio.coded_framesize = avio_rb32(&b);
1574             avio_skip(&b, 12);
1575             track->audio.sub_packet_h    = avio_rb16(&b);
1576             track->audio.frame_size      = avio_rb16(&b);
1577             track->audio.sub_packet_size = avio_rb16(&b);
1578             track->audio.buf = av_malloc(track->audio.frame_size * track->audio.sub_packet_h);
1579             if (codec_id == CODEC_ID_RA_288) {
1580                 st->codec->block_align = track->audio.coded_framesize;
1581                 track->codec_priv.size = 0;
1582             } else {
1583                 if (codec_id == CODEC_ID_SIPR && flavor < 4) {
1584                     const int sipr_bit_rate[4] = { 6504, 8496, 5000, 16000 };
1585                     track->audio.sub_packet_size = ff_sipr_subpk_size[flavor];
1586                     st->codec->bit_rate = sipr_bit_rate[flavor];
1587                 }
1588                 st->codec->block_align = track->audio.sub_packet_size;
1589                 extradata_offset = 78;
1590             }
1591         }
1592         track->codec_priv.size -= extradata_offset;
1593
1594         if (codec_id == CODEC_ID_NONE)
1595             av_log(matroska->ctx, AV_LOG_INFO,
1596                    "Unknown/unsupported CodecID %s.\n", track->codec_id);
1597
1598         if (track->time_scale < 0.01)
1599             track->time_scale = 1.0;
1600         avpriv_set_pts_info(st, 64, matroska->time_scale*track->time_scale, 1000*1000*1000); /* 64 bit pts in ns */
1601
1602         st->codec->codec_id = codec_id;
1603         st->start_time = 0;
1604         if (strcmp(track->language, "und"))
1605             av_dict_set(&st->metadata, "language", track->language, 0);
1606         av_dict_set(&st->metadata, "title", track->name, 0);
1607
1608         if (track->flag_default)
1609             st->disposition |= AV_DISPOSITION_DEFAULT;
1610         if (track->flag_forced)
1611             st->disposition |= AV_DISPOSITION_FORCED;
1612
1613         if (!st->codec->extradata) {
1614             if(extradata){
1615                 st->codec->extradata = extradata;
1616                 st->codec->extradata_size = extradata_size;
1617             } else if(track->codec_priv.data && track->codec_priv.size > 0){
1618                 st->codec->extradata = av_mallocz(track->codec_priv.size +
1619                                                   FF_INPUT_BUFFER_PADDING_SIZE);
1620                 if(st->codec->extradata == NULL)
1621                     return AVERROR(ENOMEM);
1622                 st->codec->extradata_size = track->codec_priv.size;
1623                 memcpy(st->codec->extradata,
1624                        track->codec_priv.data + extradata_offset,
1625                        track->codec_priv.size);
1626             }
1627         }
1628
1629         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1630             MatroskaTrackPlane *planes = track->operation.combine_planes.elem;
1631
1632             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
1633             st->codec->codec_tag  = fourcc;
1634             st->codec->width  = track->video.pixel_width;
1635             st->codec->height = track->video.pixel_height;
1636             av_reduce(&st->sample_aspect_ratio.num,
1637                       &st->sample_aspect_ratio.den,
1638                       st->codec->height * track->video.display_width,
1639                       st->codec-> width * track->video.display_height,
1640                       255);
1641             st->need_parsing = AVSTREAM_PARSE_HEADERS;
1642             if (track->default_duration)
1643                 st->avg_frame_rate = av_d2q(1000000000.0/track->default_duration, INT_MAX);
1644
1645             /* export stereo mode flag as metadata tag */
1646             if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREO_MODE_COUNT)
1647                 av_dict_set(&st->metadata, "stereo_mode", matroska_video_stereo_mode[track->video.stereo_mode], 0);
1648
1649             /* if we have virtual track, mark the real tracks */
1650             for (j=0; j < track->operation.combine_planes.nb_elem; j++) {
1651                 char buf[32];
1652                 if (planes[j].type >= MATROSKA_VIDEO_STEREO_PLANE_COUNT)
1653                     continue;
1654                 snprintf(buf, sizeof(buf), "%s_%d",
1655                          matroska_video_stereo_plane[planes[j].type], i);
1656                 for (k=0; k < matroska->tracks.nb_elem; k++)
1657                     if (planes[j].uid == tracks[k].uid) {
1658                         av_dict_set(&s->streams[k]->metadata,
1659                                     "stereo_mode", buf, 0);
1660                         break;
1661                     }
1662             }
1663         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1664             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
1665             st->codec->sample_rate = track->audio.out_samplerate;
1666             st->codec->channels = track->audio.channels;
1667             if (st->codec->codec_id != CODEC_ID_AAC)
1668             st->need_parsing = AVSTREAM_PARSE_HEADERS;
1669         } else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
1670             st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
1671         }
1672     }
1673
1674     attachements = attachements_list->elem;
1675     for (j=0; j<attachements_list->nb_elem; j++) {
1676         if (!(attachements[j].filename && attachements[j].mime &&
1677               attachements[j].bin.data && attachements[j].bin.size > 0)) {
1678             av_log(matroska->ctx, AV_LOG_ERROR, "incomplete attachment\n");
1679         } else {
1680             AVStream *st = avformat_new_stream(s, NULL);
1681             if (st == NULL)
1682                 break;
1683             av_dict_set(&st->metadata, "filename",attachements[j].filename, 0);
1684             av_dict_set(&st->metadata, "mimetype", attachements[j].mime, 0);
1685             st->codec->codec_id = CODEC_ID_NONE;
1686             st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
1687             st->codec->extradata  = av_malloc(attachements[j].bin.size + FF_INPUT_BUFFER_PADDING_SIZE);
1688             if(st->codec->extradata == NULL)
1689                 break;
1690             st->codec->extradata_size = attachements[j].bin.size;
1691             memcpy(st->codec->extradata, attachements[j].bin.data, attachements[j].bin.size);
1692
1693             for (i=0; ff_mkv_mime_tags[i].id != CODEC_ID_NONE; i++) {
1694                 if (!strncmp(ff_mkv_mime_tags[i].str, attachements[j].mime,
1695                              strlen(ff_mkv_mime_tags[i].str))) {
1696                     st->codec->codec_id = ff_mkv_mime_tags[i].id;
1697                     break;
1698                 }
1699             }
1700             attachements[j].stream = st;
1701         }
1702     }
1703
1704     chapters = chapters_list->elem;
1705     for (i=0; i<chapters_list->nb_elem; i++)
1706         if (chapters[i].start != AV_NOPTS_VALUE && chapters[i].uid
1707             && (max_start==0 || chapters[i].start > max_start)) {
1708             chapters[i].chapter =
1709             avpriv_new_chapter(s, chapters[i].uid, (AVRational){1, 1000000000},
1710                            chapters[i].start, chapters[i].end,
1711                            chapters[i].title);
1712             av_dict_set(&chapters[i].chapter->metadata,
1713                              "title", chapters[i].title, 0);
1714             max_start = chapters[i].start;
1715         }
1716
1717     matroska_add_index_entries(matroska);
1718
1719     matroska_convert_tags(s);
1720
1721     return 0;
1722 }
1723
1724 /*
1725  * Put one packet in an application-supplied AVPacket struct.
1726  * Returns 0 on success or -1 on failure.
1727  */
1728 static int matroska_deliver_packet(MatroskaDemuxContext *matroska,
1729                                    AVPacket *pkt)
1730 {
1731     if (matroska->num_packets > 0) {
1732         memcpy(pkt, matroska->packets[0], sizeof(AVPacket));
1733         av_free(matroska->packets[0]);
1734         if (matroska->num_packets > 1) {
1735             void *newpackets;
1736             memmove(&matroska->packets[0], &matroska->packets[1],
1737                     (matroska->num_packets - 1) * sizeof(AVPacket *));
1738             newpackets = av_realloc(matroska->packets,
1739                             (matroska->num_packets - 1) * sizeof(AVPacket *));
1740             if (newpackets)
1741                 matroska->packets = newpackets;
1742         } else {
1743             av_freep(&matroska->packets);
1744         }
1745         matroska->num_packets--;
1746         return 0;
1747     }
1748
1749     return -1;
1750 }
1751
1752 /*
1753  * Free all packets in our internal queue.
1754  */
1755 static void matroska_clear_queue(MatroskaDemuxContext *matroska)
1756 {
1757     if (matroska->packets) {
1758         int n;
1759         for (n = 0; n < matroska->num_packets; n++) {
1760             av_free_packet(matroska->packets[n]);
1761             av_free(matroska->packets[n]);
1762         }
1763         av_freep(&matroska->packets);
1764         matroska->num_packets = 0;
1765     }
1766 }
1767
1768 static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
1769                                 int size, int64_t pos, uint64_t cluster_time,
1770                                 uint64_t duration, int is_keyframe,
1771                                 int64_t cluster_pos)
1772 {
1773     uint64_t timecode = AV_NOPTS_VALUE;
1774     MatroskaTrack *track;
1775     int res = 0;
1776     AVStream *st;
1777     AVPacket *pkt;
1778     int16_t block_time;
1779     uint32_t *lace_size = NULL;
1780     int n, flags, laces = 0;
1781     uint64_t num;
1782
1783     if ((n = matroska_ebmlnum_uint(matroska, data, size, &num)) < 0) {
1784         av_log(matroska->ctx, AV_LOG_ERROR, "EBML block data error\n");
1785         return AVERROR_INVALIDDATA;
1786     }
1787     data += n;
1788     size -= n;
1789
1790     track = matroska_find_track_by_num(matroska, num);
1791     if (!track || !track->stream) {
1792         av_log(matroska->ctx, AV_LOG_INFO,
1793                "Invalid stream %"PRIu64" or size %u\n", num, size);
1794         return AVERROR_INVALIDDATA;
1795     } else if (size <= 3)
1796         return 0;
1797     st = track->stream;
1798     if (st->discard >= AVDISCARD_ALL)
1799         return res;
1800     if (!duration)
1801         duration = track->default_duration / matroska->time_scale;
1802
1803     block_time = AV_RB16(data);
1804     data += 2;
1805     flags = *data++;
1806     size -= 3;
1807     if (is_keyframe == -1)
1808         is_keyframe = flags & 0x80 ? AV_PKT_FLAG_KEY : 0;
1809
1810     if (cluster_time != (uint64_t)-1
1811         && (block_time >= 0 || cluster_time >= -block_time)) {
1812         timecode = cluster_time + block_time;
1813         if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE
1814             && timecode < track->end_timecode)
1815             is_keyframe = 0;  /* overlapping subtitles are not key frame */
1816         if (is_keyframe)
1817             av_add_index_entry(st, cluster_pos, timecode, 0,0,AVINDEX_KEYFRAME);
1818         track->end_timecode = FFMAX(track->end_timecode, timecode+duration);
1819     }
1820
1821     if (matroska->skip_to_keyframe && track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
1822         if (!is_keyframe || timecode < matroska->skip_to_timecode)
1823             return res;
1824         matroska->skip_to_keyframe = 0;
1825     }
1826
1827     switch ((flags & 0x06) >> 1) {
1828         case 0x0: /* no lacing */
1829             laces = 1;
1830             lace_size = av_mallocz(sizeof(int));
1831             lace_size[0] = size;
1832             break;
1833
1834         case 0x1: /* Xiph lacing */
1835         case 0x2: /* fixed-size lacing */
1836         case 0x3: /* EBML lacing */
1837             assert(size>0); // size <=3 is checked before size-=3 above
1838             laces = (*data) + 1;
1839             data += 1;
1840             size -= 1;
1841             lace_size = av_mallocz(laces * sizeof(int));
1842
1843             switch ((flags & 0x06) >> 1) {
1844                 case 0x1: /* Xiph lacing */ {
1845                     uint8_t temp;
1846                     uint32_t total = 0;
1847                     for (n = 0; res == 0 && n < laces - 1; n++) {
1848                         while (1) {
1849                             if (size == 0) {
1850                                 res = -1;
1851                                 break;
1852                             }
1853                             temp = *data;
1854                             lace_size[n] += temp;
1855                             data += 1;
1856                             size -= 1;
1857                             if (temp != 0xff)
1858                                 break;
1859                         }
1860                         total += lace_size[n];
1861                     }
1862                     lace_size[n] = size - total;
1863                     break;
1864                 }
1865
1866                 case 0x2: /* fixed-size lacing */
1867                     for (n = 0; n < laces; n++)
1868                         lace_size[n] = size / laces;
1869                     break;
1870
1871                 case 0x3: /* EBML lacing */ {
1872                     uint32_t total;
1873                     n = matroska_ebmlnum_uint(matroska, data, size, &num);
1874                     if (n < 0) {
1875                         av_log(matroska->ctx, AV_LOG_INFO,
1876                                "EBML block data error\n");
1877                         break;
1878                     }
1879                     data += n;
1880                     size -= n;
1881                     total = lace_size[0] = num;
1882                     for (n = 1; res == 0 && n < laces - 1; n++) {
1883                         int64_t snum;
1884                         int r;
1885                         r = matroska_ebmlnum_sint(matroska, data, size, &snum);
1886                         if (r < 0) {
1887                             av_log(matroska->ctx, AV_LOG_INFO,
1888                                    "EBML block data error\n");
1889                             break;
1890                         }
1891                         data += r;
1892                         size -= r;
1893                         lace_size[n] = lace_size[n - 1] + snum;
1894                         total += lace_size[n];
1895                     }
1896                     lace_size[laces - 1] = size - total;
1897                     break;
1898                 }
1899             }
1900             break;
1901     }
1902
1903     if (res == 0) {
1904         for (n = 0; n < laces; n++) {
1905             if ((st->codec->codec_id == CODEC_ID_RA_288 ||
1906                  st->codec->codec_id == CODEC_ID_COOK ||
1907                  st->codec->codec_id == CODEC_ID_SIPR ||
1908                  st->codec->codec_id == CODEC_ID_ATRAC3) &&
1909                  st->codec->block_align && track->audio.sub_packet_size) {
1910                 int a = st->codec->block_align;
1911                 int sps = track->audio.sub_packet_size;
1912                 int cfs = track->audio.coded_framesize;
1913                 int h = track->audio.sub_packet_h;
1914                 int y = track->audio.sub_packet_cnt;
1915                 int w = track->audio.frame_size;
1916                 int x;
1917
1918                 if (!track->audio.pkt_cnt) {
1919                     if (track->audio.sub_packet_cnt == 0)
1920                         track->audio.buf_timecode = timecode;
1921                     if (st->codec->codec_id == CODEC_ID_RA_288)
1922                         for (x=0; x<h/2; x++)
1923                             memcpy(track->audio.buf+x*2*w+y*cfs,
1924                                    data+x*cfs, cfs);
1925                     else if (st->codec->codec_id == CODEC_ID_SIPR)
1926                         memcpy(track->audio.buf + y*w, data, w);
1927                     else
1928                         for (x=0; x<w/sps; x++)
1929                             memcpy(track->audio.buf+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), data+x*sps, sps);
1930
1931                     if (++track->audio.sub_packet_cnt >= h) {
1932                         if (st->codec->codec_id == CODEC_ID_SIPR)
1933                             ff_rm_reorder_sipr_data(track->audio.buf, h, w);
1934                         track->audio.sub_packet_cnt = 0;
1935                         track->audio.pkt_cnt = h*w / a;
1936                     }
1937                 }
1938                 while (track->audio.pkt_cnt) {
1939                     pkt = av_mallocz(sizeof(AVPacket));
1940                     av_new_packet(pkt, a);
1941                     memcpy(pkt->data, track->audio.buf
1942                            + a * (h*w / a - track->audio.pkt_cnt--), a);
1943                     pkt->pts = track->audio.buf_timecode;
1944                     track->audio.buf_timecode = AV_NOPTS_VALUE;
1945                     pkt->pos = pos;
1946                     pkt->stream_index = st->index;
1947                     dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
1948                 }
1949             } else {
1950                 MatroskaTrackEncoding *encodings = track->encodings.elem;
1951                 int offset = 0, pkt_size = lace_size[n];
1952                 uint8_t *pkt_data = data;
1953
1954                 if (pkt_size > size) {
1955                     av_log(matroska->ctx, AV_LOG_ERROR, "Invalid packet size\n");
1956                     break;
1957                 }
1958
1959                 if (encodings && encodings->scope & 1) {
1960                     offset = matroska_decode_buffer(&pkt_data,&pkt_size, track);
1961                     if (offset < 0)
1962                         continue;
1963                 }
1964
1965                 pkt = av_mallocz(sizeof(AVPacket));
1966                 /* XXX: prevent data copy... */
1967                 if (av_new_packet(pkt, pkt_size+offset) < 0) {
1968                     av_free(pkt);
1969                     res = AVERROR(ENOMEM);
1970                     break;
1971                 }
1972                 if (offset)
1973                     memcpy (pkt->data, encodings->compression.settings.data, offset);
1974                 memcpy (pkt->data+offset, pkt_data, pkt_size);
1975
1976                 if (pkt_data != data)
1977                     av_free(pkt_data);
1978
1979                 if (n == 0)
1980                     pkt->flags = is_keyframe;
1981                 pkt->stream_index = st->index;
1982
1983                 if (track->ms_compat)
1984                     pkt->dts = timecode;
1985                 else
1986                     pkt->pts = timecode;
1987                 pkt->pos = pos;
1988                 if (st->codec->codec_id == CODEC_ID_TEXT)
1989                     pkt->convergence_duration = duration;
1990                 else if (track->type != MATROSKA_TRACK_TYPE_SUBTITLE)
1991                     pkt->duration = duration;
1992
1993                 if (st->codec->codec_id == CODEC_ID_SSA)
1994                     matroska_fix_ass_packet(matroska, pkt, duration);
1995
1996                 if (matroska->prev_pkt &&
1997                     timecode != AV_NOPTS_VALUE &&
1998                     matroska->prev_pkt->pts == timecode &&
1999                     matroska->prev_pkt->stream_index == st->index &&
2000                     st->codec->codec_id == CODEC_ID_SSA)
2001                     matroska_merge_packets(matroska->prev_pkt, pkt);
2002                 else {
2003                     dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
2004                     matroska->prev_pkt = pkt;
2005                 }
2006             }
2007
2008             if (timecode != AV_NOPTS_VALUE)
2009                 timecode = duration ? timecode + duration : AV_NOPTS_VALUE;
2010             data += lace_size[n];
2011             size -= lace_size[n];
2012         }
2013     }
2014
2015     av_free(lace_size);
2016     return res;
2017 }
2018
2019 static int matroska_parse_cluster(MatroskaDemuxContext *matroska)
2020 {
2021     MatroskaCluster cluster = { 0 };
2022     EbmlList *blocks_list;
2023     MatroskaBlock *blocks;
2024     int i, res;
2025     int64_t pos = avio_tell(matroska->ctx->pb);
2026     matroska->prev_pkt = NULL;
2027     if (matroska->current_id)
2028         pos -= 4;  /* sizeof the ID which was already read */
2029     res = ebml_parse(matroska, matroska_clusters, &cluster);
2030     blocks_list = &cluster.blocks;
2031     blocks = blocks_list->elem;
2032     for (i=0; i<blocks_list->nb_elem; i++)
2033         if (blocks[i].bin.size > 0 && blocks[i].bin.data) {
2034             int is_keyframe = blocks[i].non_simple ? !blocks[i].reference : -1;
2035             res=matroska_parse_block(matroska,
2036                                      blocks[i].bin.data, blocks[i].bin.size,
2037                                      blocks[i].bin.pos,  cluster.timecode,
2038                                      blocks[i].duration, is_keyframe,
2039                                      pos);
2040         }
2041     ebml_free(matroska_cluster, &cluster);
2042     return res;
2043 }
2044
2045 static int matroska_read_packet(AVFormatContext *s, AVPacket *pkt)
2046 {
2047     MatroskaDemuxContext *matroska = s->priv_data;
2048
2049     while (matroska_deliver_packet(matroska, pkt)) {
2050         int64_t pos = avio_tell(matroska->ctx->pb);
2051         if (matroska->done)
2052             return AVERROR_EOF;
2053         if (matroska_parse_cluster(matroska) < 0)
2054             matroska_resync(matroska, pos);
2055     }
2056
2057     return 0;
2058 }
2059
2060 static int matroska_read_seek(AVFormatContext *s, int stream_index,
2061                               int64_t timestamp, int flags)
2062 {
2063     MatroskaDemuxContext *matroska = s->priv_data;
2064     MatroskaTrack *tracks = matroska->tracks.elem;
2065     AVStream *st = s->streams[stream_index];
2066     int i, index, index_sub, index_min;
2067
2068     /* Parse the CUES now since we need the index data to seek. */
2069     if (matroska->cues_parsing_deferred > 0) {
2070         matroska->cues_parsing_deferred = 0;
2071         matroska_parse_cues(matroska);
2072     }
2073
2074     if (!st->nb_index_entries)
2075         goto err;
2076     timestamp = FFMAX(timestamp, st->index_entries[0].timestamp);
2077
2078     if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
2079         avio_seek(s->pb, st->index_entries[st->nb_index_entries-1].pos, SEEK_SET);
2080         matroska->current_id = 0;
2081         while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
2082             matroska_clear_queue(matroska);
2083             if (matroska_parse_cluster(matroska) < 0)
2084                 break;
2085         }
2086     }
2087
2088     matroska_clear_queue(matroska);
2089     if (index < 0 || (matroska->cues_parsing_deferred < 0 && index == st->nb_index_entries - 1))
2090         goto err;
2091
2092     index_min = index;
2093     for (i=0; i < matroska->tracks.nb_elem; i++) {
2094         tracks[i].audio.pkt_cnt = 0;
2095         tracks[i].audio.sub_packet_cnt = 0;
2096         tracks[i].audio.buf_timecode = AV_NOPTS_VALUE;
2097         tracks[i].end_timecode = 0;
2098         if (tracks[i].type == MATROSKA_TRACK_TYPE_SUBTITLE
2099             && !tracks[i].stream->discard != AVDISCARD_ALL) {
2100             index_sub = av_index_search_timestamp(tracks[i].stream, st->index_entries[index].timestamp, AVSEEK_FLAG_BACKWARD);
2101             if (index_sub >= 0
2102                 && st->index_entries[index_sub].pos < st->index_entries[index_min].pos
2103                 && st->index_entries[index].timestamp - st->index_entries[index_sub].timestamp < 30000000000/matroska->time_scale)
2104                 index_min = index_sub;
2105         }
2106     }
2107
2108     avio_seek(s->pb, st->index_entries[index_min].pos, SEEK_SET);
2109     matroska->current_id = 0;
2110     matroska->skip_to_keyframe = !(flags & AVSEEK_FLAG_ANY);
2111     matroska->skip_to_timecode = st->index_entries[index].timestamp;
2112     matroska->done = 0;
2113     matroska->num_levels = 0;
2114     ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
2115     return 0;
2116 err:
2117     // slightly hackish but allows proper fallback to
2118     // the generic seeking code.
2119     matroska_clear_queue(matroska);
2120     matroska->current_id = 0;
2121     matroska->skip_to_keyframe = 0;
2122     matroska->done = 0;
2123     matroska->num_levels = 0;
2124     return -1;
2125 }
2126
2127 static int matroska_read_close(AVFormatContext *s)
2128 {
2129     MatroskaDemuxContext *matroska = s->priv_data;
2130     MatroskaTrack *tracks = matroska->tracks.elem;
2131     int n;
2132
2133     matroska_clear_queue(matroska);
2134
2135     for (n=0; n < matroska->tracks.nb_elem; n++)
2136         if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)
2137             av_free(tracks[n].audio.buf);
2138     ebml_free(matroska_segment, matroska);
2139
2140     return 0;
2141 }
2142
2143 AVInputFormat ff_matroska_demuxer = {
2144     .name           = "matroska,webm",
2145     .long_name      = NULL_IF_CONFIG_SMALL("Matroska/WebM file format"),
2146     .priv_data_size = sizeof(MatroskaDemuxContext),
2147     .read_probe     = matroska_probe,
2148     .read_header    = matroska_read_header,
2149     .read_packet    = matroska_read_packet,
2150     .read_close     = matroska_read_close,
2151     .read_seek      = matroska_read_seek,
2152 };