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         }
 660         return AVERROR(EIO); /* EOS or actual I/O error */
 661     }
 662
 663     /* get the length of the EBML number */
 664     read = 8 - ff_log2_tab[total];
 665     if (read > max_size) {
 666         int64_t pos = avio_tell(pb) - 1;
 667         av_log(matroska->ctx, AV_LOG_ERROR,
 668                "Invalid EBML number size tag 0x%02x at pos %"PRIu64" (0x%"PRIx64")\n",
 669                (uint8_t) total, pos, pos);
 670         return AVERROR_INVALIDDATA;
 671     }
 672
 673     /* read out length */
 674     total ^= 1 << ff_log2_tab[total];
 675     while (n++ < read)
 676         total = (total << 8) | avio_r8(pb);
 677
 678     *number = total;
 679
 680     return read;
 681 }
 682
 683 /**
 684  * Read a EBML length value.
 685  * This needs special handling for the "unknown length" case which has multiple
 686  * encodings.
 687  */
 688 static int ebml_read_length(MatroskaDemuxContext *matroska, AVIOContext *pb,
 689                             uint64_t *number)
 690 {
 691     int res = ebml_read_num(matroska, pb, 8, number);
 692     if (res > 0 && *number + 1 == 1ULL << (7 * res))
 693         *number = 0xffffffffffffffULL;
 694     return res;
 695 }
 696
 697 /*
 698  * Read the next element as an unsigned int.
 699  * 0 is success, < 0 is failure.
 700  */
 701 static int ebml_read_uint(AVIOContext *pb, int size, uint64_t *num)
 702 {
 703     int n = 0;
 704
 705     if (size > 8)
 706         return AVERROR_INVALIDDATA;
 707
 708     /* big-endian ordering; build up number */
 709     *num = 0;
 710     while (n++ < size)
 711         *num = (*num << 8) | avio_r8(pb);
 712
 713     return 0;
 714 }
 715
 716 /*
 717  * Read the next element as a float.
 718  * 0 is success, < 0 is failure.
 719  */
 720 static int ebml_read_float(AVIOContext *pb, int size, double *num)
 721 {
 722     if (size == 0) {
 723         *num = 0;
 724     } else if (size == 4) {
 725         *num = av_int2float(avio_rb32(pb));
 726     } else if (size == 8){
 727         *num = av_int2double(avio_rb64(pb));
 728     } else
 729         return AVERROR_INVALIDDATA;
 730
 731     return 0;
 732 }
 733
 734 /*
 735  * Read the next element as an ASCII string.
 736  * 0 is success, < 0 is failure.
 737  */
 738 static int ebml_read_ascii(AVIOContext *pb, int size, char **str)
 739 {
 740     char *res;
 741
 742     /* EBML strings are usually not 0-terminated, so we allocate one
 743      * byte more, read the string and NULL-terminate it ourselves. */
 744     if (!(res = av_malloc(size + 1)))
 745         return AVERROR(ENOMEM);
 746     if (avio_read(pb, (uint8_t *) res, size) != size) {
 747         av_free(res);
 748         return AVERROR(EIO);
 749     }
 750     (res)[size] = '\0';
 751     av_free(*str);
 752     *str = res;
 753
 754     return 0;
 755 }
 756
 757 /*
 758  * Read the next element as binary data.
 759  * 0 is success, < 0 is failure.
 760  */
 761 static int ebml_read_binary(AVIOContext *pb, int length, EbmlBin *bin)
 762 {
 763     av_free(bin->data);
 764     if (!(bin->data = av_malloc(length)))
 765         return AVERROR(ENOMEM);
 766
 767     bin->size = length;
 768     bin->pos  = avio_tell(pb);
 769     if (avio_read(pb, bin->data, length) != length) {
 770         av_freep(&bin->data);
 771         return AVERROR(EIO);
 772     }
 773
 774     return 0;
 775 }
 776
 777 /*
 778  * Read the next element, but only the header. The contents
 779  * are supposed to be sub-elements which can be read separately.
 780  * 0 is success, < 0 is failure.
 781  */
 782 static int ebml_read_master(MatroskaDemuxContext *matroska, uint64_t length)
 783 {
 784     AVIOContext *pb = matroska->ctx->pb;
 785     MatroskaLevel *level;
 786
 787     if (matroska->num_levels >= EBML_MAX_DEPTH) {
 788         av_log(matroska->ctx, AV_LOG_ERROR,
 789                "File moves beyond max. allowed depth (%d)\n", EBML_MAX_DEPTH);
 790         return AVERROR(ENOSYS);
 791     }
 792
 793     level = &matroska->levels[matroska->num_levels++];
 794     level->start = avio_tell(pb);
 795     level->length = length;
 796
 797     return 0;
 798 }
 799
 800 /*
 801  * Read signed/unsigned "EBML" numbers.
 802  * Return: number of bytes processed, < 0 on error
 803  */
 804 static int matroska_ebmlnum_uint(MatroskaDemuxContext *matroska,
 805                                  uint8_t *data, uint32_t size, uint64_t *num)
 806 {
 807     AVIOContext pb;
 808     ffio_init_context(&pb, data, size, 0, NULL, NULL, NULL, NULL);
 809     return ebml_read_num(matroska, &pb, FFMIN(size, 8), num);
 810 }
 811
 812 /*
 813  * Same as above, but signed.
 814  */
 815 static int matroska_ebmlnum_sint(MatroskaDemuxContext *matroska,
 816                                  uint8_t *data, uint32_t size, int64_t *num)
 817 {
 818     uint64_t unum;
 819     int res;
 820
 821     /* read as unsigned number first */
 822     if ((res = matroska_ebmlnum_uint(matroska, data, size, &unum)) < 0)
 823         return res;
 824
 825     /* make signed (weird way) */
 826     *num = unum - ((1LL << (7*res - 1)) - 1);
 827
 828     return res;
 829 }
 830
 831 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
 832                            EbmlSyntax *syntax, void *data);
 833
 834 static int ebml_parse_id(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 835                          uint32_t id, void *data)
 836 {
 837     int i;
 838     for (i=0; syntax[i].id; i++)
 839         if (id == syntax[i].id)
 840             break;
 841     if (!syntax[i].id && id == MATROSKA_ID_CLUSTER &&
 842         matroska->num_levels > 0 &&
 843         matroska->levels[matroska->num_levels-1].length == 0xffffffffffffff)
 844         return 0;  // we reached the end of an unknown size cluster
 845     if (!syntax[i].id && id != EBML_ID_VOID && id != EBML_ID_CRC32) {
 846         av_log(matroska->ctx, AV_LOG_INFO, "Unknown entry 0x%X\n", id);
 847         if (matroska->ctx->error_recognition & AV_EF_EXPLODE)
 848             return AVERROR_INVALIDDATA;
 849     }
 850     return ebml_parse_elem(matroska, &syntax[i], data);
 851 }
 852
 853 static int ebml_parse(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 854                       void *data)
 855 {
 856     if (!matroska->current_id) {
 857         uint64_t id;
 858         int res = ebml_read_num(matroska, matroska->ctx->pb, 4, &id);
 859         if (res < 0)
 860             return res;
 861         matroska->current_id = id | 1 << 7*res;
 862     }
 863     return ebml_parse_id(matroska, syntax, matroska->current_id, data);
 864 }
 865
 866 static int ebml_parse_nest(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 867                            void *data)
 868 {
 869     int i, res = 0;
 870
 871     for (i=0; syntax[i].id; i++)
 872         switch (syntax[i].type) {
 873         case EBML_UINT:
 874             *(uint64_t *)((char *)data+syntax[i].data_offset) = syntax[i].def.u;
 875             break;
 876         case EBML_FLOAT:
 877             *(double   *)((char *)data+syntax[i].data_offset) = syntax[i].def.f;
 878             break;
 879         case EBML_STR:
 880         case EBML_UTF8:
 881             *(char    **)((char *)data+syntax[i].data_offset) = av_strdup(syntax[i].def.s);
 882             break;
 883         }
 884
 885     while (!res && !ebml_level_end(matroska))
 886         res = ebml_parse(matroska, syntax, data);
 887
 888     return res;
 889 }
 890
 891 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
 892                            EbmlSyntax *syntax, void *data)
 893 {
 894     static const uint64_t max_lengths[EBML_TYPE_COUNT] = {
 895         [EBML_UINT]  = 8,
 896         [EBML_FLOAT] = 8,
 897         // max. 16 MB for strings
 898         [EBML_STR]   = 0x1000000,
 899         [EBML_UTF8]  = 0x1000000,
 900         // max. 256 MB for binary data
 901         [EBML_BIN]   = 0x10000000,
 902         // no limits for anything else
 903     };
 904     AVIOContext *pb = matroska->ctx->pb;
 905     uint32_t id = syntax->id;
 906     uint64_t length;
 907     int res;
 908     void *newelem;
 909
 910     data = (char *)data + syntax->data_offset;
 911     if (syntax->list_elem_size) {
 912         EbmlList *list = data;
 913         newelem = av_realloc(list->elem, (list->nb_elem+1)*syntax->list_elem_size);
 914         if (!newelem)
 915             return AVERROR(ENOMEM);
 916         list->elem = newelem;
 917         data = (char*)list->elem + list->nb_elem*syntax->list_elem_size;
 918         memset(data, 0, syntax->list_elem_size);
 919         list->nb_elem++;
 920     }
 921
 922     if (syntax->type != EBML_PASS && syntax->type != EBML_STOP) {
 923         matroska->current_id = 0;
 924         if ((res = ebml_read_length(matroska, pb, &length)) < 0)
 925             return res;
 926         if (max_lengths[syntax->type] && length > max_lengths[syntax->type]) {
 927             av_log(matroska->ctx, AV_LOG_ERROR,
 928                    "Invalid length 0x%"PRIx64" > 0x%"PRIx64" for syntax element %i\n",
 929                    length, max_lengths[syntax->type], syntax->type);
 930             return AVERROR_INVALIDDATA;
 931         }
 932     }
 933
 934     switch (syntax->type) {
 935     case EBML_UINT:  res = ebml_read_uint  (pb, length, data);  break;
 936     case EBML_FLOAT: res = ebml_read_float (pb, length, data);  break;
 937     case EBML_STR:
 938     case EBML_UTF8:  res = ebml_read_ascii (pb, length, data);  break;
 939     case EBML_BIN:   res = ebml_read_binary(pb, length, data);  break;
 940     case EBML_NEST:  if ((res=ebml_read_master(matroska, length)) < 0)
 941                          return res;
 942                      if (id == MATROSKA_ID_SEGMENT)
 943                          matroska->segment_start = avio_tell(matroska->ctx->pb);
 944                      return ebml_parse_nest(matroska, syntax->def.n, data);
 945     case EBML_PASS:  return ebml_parse_id(matroska, syntax->def.n, id, data);
 946     case EBML_STOP:  return 1;
 947     default:         return avio_skip(pb,length)<0 ? AVERROR(EIO) : 0;
 948     }
 949     if (res == AVERROR_INVALIDDATA)
 950         av_log(matroska->ctx, AV_LOG_ERROR, "Invalid element\n");
 951     else if (res == AVERROR(EIO))
 952         av_log(matroska->ctx, AV_LOG_ERROR, "Read error\n");
 953     return res;
 954 }
 955
 956 static void ebml_free(EbmlSyntax *syntax, void *data)
 957 {
 958     int i, j;
 959     for (i=0; syntax[i].id; i++) {
 960         void *data_off = (char *)data + syntax[i].data_offset;
 961         switch (syntax[i].type) {
 962         case EBML_STR:
 963         case EBML_UTF8:  av_freep(data_off);                      break;
 964         case EBML_BIN:   av_freep(&((EbmlBin *)data_off)->data);  break;
 965         case EBML_NEST:
 966             if (syntax[i].list_elem_size) {
 967                 EbmlList *list = data_off;
 968                 char *ptr = list->elem;
 969                 for (j=0; j<list->nb_elem; j++, ptr+=syntax[i].list_elem_size)
 970                     ebml_free(syntax[i].def.n, ptr);
 971                 av_free(list->elem);
 972             } else
 973                 ebml_free(syntax[i].def.n, data_off);
 974         default:  break;
 975         }
 976     }
 977 }
 978
 979
 980 /*
 981  * Autodetecting...
 982  */
 983 static int matroska_probe(AVProbeData *p)
 984 {
 985     uint64_t total = 0;
 986     int len_mask = 0x80, size = 1, n = 1, i;
 987
 988     /* EBML header? */
 989     if (AV_RB32(p->buf) != EBML_ID_HEADER)
 990         return 0;
 991
 992     /* length of header */
 993     total = p->buf[4];
 994     while (size <= 8 && !(total & len_mask)) {
 995         size++;
 996         len_mask >>= 1;
 997     }
 998     if (size > 8)
 999       return 0;
1000     total &= (len_mask - 1);
1001     while (n < size)
1002         total = (total << 8) | p->buf[4 + n++];
1003
1004     /* Does the probe data contain the whole header? */
1005     if (p->buf_size < 4 + size + total)
1006       return 0;
1007
1008     /* The header should contain a known document type. For now,
1009      * we don't parse the whole header but simply check for the
1010      * availability of that array of characters inside the header.
1011      * Not fully fool-proof, but good enough. */
1012     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++) {
1013         int probelen = strlen(matroska_doctypes[i]);
1014         if (total < probelen)
1015             continue;
1016         for (n = 4+size; n <= 4+size+total-probelen; n++)
1017             if (!memcmp(p->buf+n, matroska_doctypes[i], probelen))
1018                 return AVPROBE_SCORE_MAX;
1019     }
1020
1021     // probably valid EBML header but no recognized doctype
1022     return AVPROBE_SCORE_MAX/2;
1023 }
1024
1025 static MatroskaTrack *matroska_find_track_by_num(MatroskaDemuxContext *matroska,
1026                                                  int num)
1027 {
1028     MatroskaTrack *tracks = matroska->tracks.elem;
1029     int i;
1030
1031     for (i=0; i < matroska->tracks.nb_elem; i++)
1032         if (tracks[i].num == num)
1033             return &tracks[i];
1034
1035     av_log(matroska->ctx, AV_LOG_ERROR, "Invalid track number %d\n", num);
1036     return NULL;
1037 }
1038
1039 static int matroska_decode_buffer(uint8_t** buf, int* buf_size,
1040                                   MatroskaTrack *track)
1041 {
1042     MatroskaTrackEncoding *encodings = track->encodings.elem;
1043     uint8_t* data = *buf;
1044     int isize = *buf_size;
1045     uint8_t* pkt_data = NULL;
1046     uint8_t av_unused *newpktdata;
1047     int pkt_size = isize;
1048     int result = 0;
1049     int olen;
1050
1051     if (pkt_size >= 10000000U)
1052         return -1;
1053
1054     switch (encodings[0].compression.algo) {
1055     case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP:
1056         if (encodings[0].compression.settings.size && !encodings[0].compression.settings.data) {
1057             av_log(0, AV_LOG_ERROR, "Compression size but no data in headerstrip\n");
1058             return -1;
1059         }
1060         return encodings[0].compression.settings.size;
1061     case MATROSKA_TRACK_ENCODING_COMP_LZO:
1062         do {
1063             olen = pkt_size *= 3;
1064             pkt_data = av_realloc(pkt_data, pkt_size+AV_LZO_OUTPUT_PADDING);
1065             result = av_lzo1x_decode(pkt_data, &olen, data, &isize);
1066         } while (result==AV_LZO_OUTPUT_FULL && pkt_size<10000000);
1067         if (result)
1068             goto failed;
1069         pkt_size -= olen;
1070         break;
1071 #if CONFIG_ZLIB
1072     case MATROSKA_TRACK_ENCODING_COMP_ZLIB: {
1073         z_stream zstream = {0};
1074         if (inflateInit(&zstream) != Z_OK)
1075             return -1;
1076         zstream.next_in = data;
1077         zstream.avail_in = isize;
1078         do {
1079             pkt_size *= 3;
1080             newpktdata = av_realloc(pkt_data, pkt_size);
1081             if (!newpktdata) {
1082                 inflateEnd(&zstream);
1083                 goto failed;
1084             }
1085             pkt_data = newpktdata;
1086             zstream.avail_out = pkt_size - zstream.total_out;
1087             zstream.next_out = pkt_data + zstream.total_out;
1088             if (pkt_data) {
1089                 result = inflate(&zstream, Z_NO_FLUSH);
1090             } else
1091                 result = Z_MEM_ERROR;
1092         } while (result==Z_OK && pkt_size<10000000);
1093         pkt_size = zstream.total_out;
1094         inflateEnd(&zstream);
1095         if (result != Z_STREAM_END)
1096             goto failed;
1097         break;
1098     }
1099 #endif
1100 #if CONFIG_BZLIB
1101     case MATROSKA_TRACK_ENCODING_COMP_BZLIB: {
1102         bz_stream bzstream = {0};
1103         if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
1104             return -1;
1105         bzstream.next_in = data;
1106         bzstream.avail_in = isize;
1107         do {
1108             pkt_size *= 3;
1109             newpktdata = av_realloc(pkt_data, pkt_size);
1110             if (!newpktdata) {
1111                 BZ2_bzDecompressEnd(&bzstream);
1112                 goto failed;
1113             }
1114             pkt_data = newpktdata;
1115             bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
1116             bzstream.next_out = pkt_data + bzstream.total_out_lo32;
1117             if (pkt_data) {
1118                 result = BZ2_bzDecompress(&bzstream);
1119             } else
1120                 result = BZ_MEM_ERROR;
1121         } while (result==BZ_OK && pkt_size<10000000);
1122         pkt_size = bzstream.total_out_lo32;
1123         BZ2_bzDecompressEnd(&bzstream);
1124         if (result != BZ_STREAM_END)
1125             goto failed;
1126         break;
1127     }
1128 #endif
1129     default:
1130         return -1;
1131     }
1132
1133     *buf = pkt_data;
1134     *buf_size = pkt_size;
1135     return 0;
1136  failed:
1137     av_free(pkt_data);
1138     return -1;
1139 }
1140
1141 static void matroska_fix_ass_packet(MatroskaDemuxContext *matroska,
1142                                     AVPacket *pkt, uint64_t display_duration)
1143 {
1144     char *line, *layer, *ptr = pkt->data, *end = ptr+pkt->size;
1145     for (; *ptr!=',' && ptr<end-1; ptr++);
1146     if (*ptr == ',')
1147         ptr++;
1148     layer = ptr;
1149     for (; *ptr!=',' && ptr<end-1; ptr++);
1150     if (*ptr == ',') {
1151         int64_t end_pts = pkt->pts + display_duration;
1152         int sc = matroska->time_scale * pkt->pts / 10000000;
1153         int ec = matroska->time_scale * end_pts  / 10000000;
1154         int sh, sm, ss, eh, em, es, len;
1155         sh = sc/360000;  sc -= 360000*sh;
1156         sm = sc/  6000;  sc -=   6000*sm;
1157         ss = sc/   100;  sc -=    100*ss;
1158         eh = ec/360000;  ec -= 360000*eh;
1159         em = ec/  6000;  ec -=   6000*em;
1160         es = ec/   100;  ec -=    100*es;
1161         *ptr++ = '\0';
1162         len = 50 + end-ptr + FF_INPUT_BUFFER_PADDING_SIZE;
1163         if (!(line = av_malloc(len)))
1164             return;
1165         snprintf(line,len,"Dialogue: %s,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s\r\n",
1166                  layer, sh, sm, ss, sc, eh, em, es, ec, ptr);
1167         av_free(pkt->data);
1168         pkt->data = line;
1169         pkt->size = strlen(line);
1170     }
1171 }
1172
1173 static int matroska_merge_packets(AVPacket *out, AVPacket *in)
1174 {
1175     int ret = av_grow_packet(out, in->size);
1176     if (ret < 0)
1177         return ret;
1178     memcpy(out->data + out->size - in->size, in->data, in->size);
1179     av_destruct_packet(in);
1180     av_free(in);
1181     return 0;
1182 }
1183
1184 static void matroska_convert_tag(AVFormatContext *s, EbmlList *list,
1185                                  AVDictionary **metadata, char *prefix)
1186 {
1187     MatroskaTag *tags = list->elem;
1188     char key[1024];
1189     int i;
1190
1191     for (i=0; i < list->nb_elem; i++) {
1192         const char *lang= (tags[i].lang && strcmp(tags[i].lang, "und")) ? tags[i].lang : NULL;
1193
1194         if (!tags[i].name) {
1195             av_log(s, AV_LOG_WARNING, "Skipping invalid tag with no TagName.\n");
1196             continue;
1197         }
1198         if (prefix)  snprintf(key, sizeof(key), "%s/%s", prefix, tags[i].name);
1199         else         av_strlcpy(key, tags[i].name, sizeof(key));
1200         if (tags[i].def || !lang) {
1201         av_dict_set(metadata, key, tags[i].string, 0);
1202         if (tags[i].sub.nb_elem)
1203             matroska_convert_tag(s, &tags[i].sub, metadata, key);
1204         }
1205         if (lang) {
1206             av_strlcat(key, "-", sizeof(key));
1207             av_strlcat(key, lang, sizeof(key));
1208             av_dict_set(metadata, key, tags[i].string, 0);
1209             if (tags[i].sub.nb_elem)
1210                 matroska_convert_tag(s, &tags[i].sub, metadata, key);
1211         }
1212     }
1213     ff_metadata_conv(metadata, NULL, ff_mkv_metadata_conv);
1214 }
1215
1216 static void matroska_convert_tags(AVFormatContext *s)
1217 {
1218     MatroskaDemuxContext *matroska = s->priv_data;
1219     MatroskaTags *tags = matroska->tags.elem;
1220     int i, j;
1221
1222     for (i=0; i < matroska->tags.nb_elem; i++) {
1223         if (tags[i].target.attachuid) {
1224             MatroskaAttachement *attachment = matroska->attachments.elem;
1225             for (j=0; j<matroska->attachments.nb_elem; j++)
1226                 if (attachment[j].uid == tags[i].target.attachuid
1227                     && attachment[j].stream)
1228                     matroska_convert_tag(s, &tags[i].tag,
1229                                          &attachment[j].stream->metadata, NULL);
1230         } else if (tags[i].target.chapteruid) {
1231             MatroskaChapter *chapter = matroska->chapters.elem;
1232             for (j=0; j<matroska->chapters.nb_elem; j++)
1233                 if (chapter[j].uid == tags[i].target.chapteruid
1234                     && chapter[j].chapter)
1235                     matroska_convert_tag(s, &tags[i].tag,
1236                                          &chapter[j].chapter->metadata, NULL);
1237         } else if (tags[i].target.trackuid) {
1238             MatroskaTrack *track = matroska->tracks.elem;
1239             for (j=0; j<matroska->tracks.nb_elem; j++)
1240                 if (track[j].uid == tags[i].target.trackuid && track[j].stream)
1241                     matroska_convert_tag(s, &tags[i].tag,
1242                                          &track[j].stream->metadata, NULL);
1243         } else {
1244             matroska_convert_tag(s, &tags[i].tag, &s->metadata,
1245                                  tags[i].target.type);
1246         }
1247     }
1248 }
1249
1250 static int matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska, int idx)
1251 {
1252     EbmlList *seekhead_list = &matroska->seekhead;
1253     MatroskaSeekhead *seekhead = seekhead_list->elem;
1254     uint32_t level_up = matroska->level_up;
1255     int64_t before_pos = avio_tell(matroska->ctx->pb);
1256     uint32_t saved_id = matroska->current_id;
1257     MatroskaLevel level;
1258     int64_t offset;
1259     int ret = 0;
1260
1261     if (idx >= seekhead_list->nb_elem
1262             || seekhead[idx].id == MATROSKA_ID_SEEKHEAD
1263             || seekhead[idx].id == MATROSKA_ID_CLUSTER)
1264         return 0;
1265
1266     /* seek */
1267     offset = seekhead[idx].pos + matroska->segment_start;
1268     if (avio_seek(matroska->ctx->pb, offset, SEEK_SET) == offset) {
1269         /* We don't want to lose our seekhead level, so we add
1270          * a dummy. This is a crude hack. */
1271         if (matroska->num_levels == EBML_MAX_DEPTH) {
1272             av_log(matroska->ctx, AV_LOG_INFO,
1273                    "Max EBML element depth (%d) reached, "
1274                    "cannot parse further.\n", EBML_MAX_DEPTH);
1275             ret = AVERROR_INVALIDDATA;
1276         } else {
1277             level.start = 0;
1278             level.length = (uint64_t)-1;
1279             matroska->levels[matroska->num_levels] = level;
1280             matroska->num_levels++;
1281             matroska->current_id = 0;
1282
1283             ret = ebml_parse(matroska, matroska_segment, matroska);
1284
1285             /* remove dummy level */
1286             while (matroska->num_levels) {
1287                 uint64_t length = matroska->levels[--matroska->num_levels].length;
1288                 if (length == (uint64_t)-1)
1289                     break;
1290             }
1291         }
1292     }
1293     /* seek back */
1294     avio_seek(matroska->ctx->pb, before_pos, SEEK_SET);
1295     matroska->level_up = level_up;
1296     matroska->current_id = saved_id;
1297
1298     return ret;
1299 }
1300
1301 static void matroska_execute_seekhead(MatroskaDemuxContext *matroska)
1302 {
1303     EbmlList *seekhead_list = &matroska->seekhead;
1304     int64_t before_pos = avio_tell(matroska->ctx->pb);
1305     int i;
1306
1307     // we should not do any seeking in the streaming case
1308     if (!matroska->ctx->pb->seekable ||
1309         (matroska->ctx->flags & AVFMT_FLAG_IGNIDX))
1310         return;
1311
1312     for (i = 0; i < seekhead_list->nb_elem; i++) {
1313         MatroskaSeekhead *seekhead = seekhead_list->elem;
1314         if (seekhead[i].pos <= before_pos)
1315             continue;
1316
1317         // defer cues parsing until we actually need cue data.
1318         if (seekhead[i].id == MATROSKA_ID_CUES) {
1319             matroska->cues_parsing_deferred = 1;
1320             continue;
1321         }
1322
1323         if (matroska_parse_seekhead_entry(matroska, i) < 0) {
1324             // mark index as broken
1325             matroska->cues_parsing_deferred = -1;
1326             break;
1327         }
1328     }
1329 }
1330
1331 static void matroska_add_index_entries(MatroskaDemuxContext *matroska) {
1332     EbmlList *index_list;
1333     MatroskaIndex *index;
1334     int index_scale = 1;
1335     int i, j;
1336
1337     index_list = &matroska->index;
1338     index = index_list->elem;
1339     if (index_list->nb_elem
1340         && index[0].time > 1E14/matroska->time_scale) {
1341         av_log(matroska->ctx, AV_LOG_WARNING, "Working around broken index.\n");
1342         index_scale = matroska->time_scale;
1343     }
1344     for (i = 0; i < index_list->nb_elem; i++) {
1345         EbmlList *pos_list = &index[i].pos;
1346         MatroskaIndexPos *pos = pos_list->elem;
1347         for (j = 0; j < pos_list->nb_elem; j++) {
1348             MatroskaTrack *track = matroska_find_track_by_num(matroska, pos[j].track);
1349             if (track && track->stream)
1350                 av_add_index_entry(track->stream,
1351                                    pos[j].pos + matroska->segment_start,
1352                                    index[i].time/index_scale, 0, 0,
1353                                    AVINDEX_KEYFRAME);
1354         }
1355     }
1356 }
1357
1358 static void matroska_parse_cues(MatroskaDemuxContext *matroska) {
1359     EbmlList *seekhead_list = &matroska->seekhead;
1360     MatroskaSeekhead *seekhead = seekhead_list->elem;
1361     int i;
1362
1363     for (i = 0; i < seekhead_list->nb_elem; i++)
1364         if (seekhead[i].id == MATROSKA_ID_CUES)
1365             break;
1366     assert(i <= seekhead_list->nb_elem);
1367
1368     if (matroska_parse_seekhead_entry(matroska, i) < 0)
1369        matroska->cues_parsing_deferred = -1;
1370     matroska_add_index_entries(matroska);
1371 }
1372
1373 static int matroska_aac_profile(char *codec_id)
1374 {
1375     static const char * const aac_profiles[] = { "MAIN", "LC", "SSR" };
1376     int profile;
1377
1378     for (profile=0; profile<FF_ARRAY_ELEMS(aac_profiles); profile++)
1379         if (strstr(codec_id, aac_profiles[profile]))
1380             break;
1381     return profile + 1;
1382 }
1383
1384 static int matroska_aac_sri(int samplerate)
1385 {
1386     int sri;
1387
1388     for (sri=0; sri<FF_ARRAY_ELEMS(avpriv_mpeg4audio_sample_rates); sri++)
1389         if (avpriv_mpeg4audio_sample_rates[sri] == samplerate)
1390             break;
1391     return sri;
1392 }
1393
1394 static void matroska_metadata_creation_time(AVDictionary **metadata, int64_t date_utc)
1395 {
1396     char buffer[32];
1397     /* Convert to seconds and adjust by number of seconds between 2001-01-01 and Epoch */
1398     time_t creation_time = date_utc / 1000000000 + 978307200;
1399     struct tm *ptm = gmtime(&creation_time);
1400     if (!ptm) return;
1401     strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", ptm);
1402     av_dict_set(metadata, "creation_time", buffer, 0);
1403 }
1404
1405 static int matroska_read_header(AVFormatContext *s)
1406 {
1407     MatroskaDemuxContext *matroska = s->priv_data;
1408     EbmlList *attachements_list = &matroska->attachments;
1409     MatroskaAttachement *attachements;
1410     EbmlList *chapters_list = &matroska->chapters;
1411     MatroskaChapter *chapters;
1412     MatroskaTrack *tracks;
1413     uint64_t max_start = 0;
1414     int64_t pos;
1415     Ebml ebml = { 0 };
1416     AVStream *st;
1417     int i, j, k, res;
1418
1419     matroska->ctx = s;
1420
1421     /* First read the EBML header. */
1422     if (ebml_parse(matroska, ebml_syntax, &ebml)
1423         || ebml.version > EBML_VERSION       || ebml.max_size > sizeof(uint64_t)
1424         || ebml.id_length > sizeof(uint32_t) || ebml.doctype_version > 3 || !ebml.doctype) {
1425         av_log(matroska->ctx, AV_LOG_ERROR,
1426                "EBML header using unsupported features\n"
1427                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
1428                ebml.version, ebml.doctype, ebml.doctype_version);
1429         ebml_free(ebml_syntax, &ebml);
1430         return AVERROR_PATCHWELCOME;
1431     } else if (ebml.doctype_version == 3) {
1432         av_log(matroska->ctx, AV_LOG_WARNING,
1433                "EBML header using unsupported features\n"
1434                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
1435                ebml.version, ebml.doctype, ebml.doctype_version);
1436     }
1437     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++)
1438         if (!strcmp(ebml.doctype, matroska_doctypes[i]))
1439             break;
1440     if (i >= FF_ARRAY_ELEMS(matroska_doctypes)) {
1441         av_log(s, AV_LOG_WARNING, "Unknown EBML doctype '%s'\n", ebml.doctype);
1442     }
1443     ebml_free(ebml_syntax, &ebml);
1444
1445     /* The next thing is a segment. */
1446     pos = avio_tell(matroska->ctx->pb);
1447     res = ebml_parse(matroska, matroska_segments, matroska);
1448     // try resyncing until we find a EBML_STOP type element.
1449     while (res != 1) {
1450         res = matroska_resync(matroska, pos);
1451         if (res < 0)
1452             return res;
1453         pos = avio_tell(matroska->ctx->pb);
1454         res = ebml_parse(matroska, matroska_segment, matroska);
1455     }
1456     matroska_execute_seekhead(matroska);
1457
1458     if (!matroska->time_scale)
1459         matroska->time_scale = 1000000;
1460     if (matroska->duration)
1461         matroska->ctx->duration = matroska->duration * matroska->time_scale
1462                                   * 1000 / AV_TIME_BASE;
1463     av_dict_set(&s->metadata, "title", matroska->title, 0);
1464
1465     if (matroska->date_utc.size == 8)
1466         matroska_metadata_creation_time(&s->metadata, AV_RB64(matroska->date_utc.data));
1467
1468     tracks = matroska->tracks.elem;
1469     for (i=0; i < matroska->tracks.nb_elem; i++) {
1470         MatroskaTrack *track = &tracks[i];
1471         enum CodecID codec_id = CODEC_ID_NONE;
1472         EbmlList *encodings_list = &track->encodings;
1473         MatroskaTrackEncoding *encodings = encodings_list->elem;
1474         uint8_t *extradata = NULL;
1475         int extradata_size = 0;
1476         int extradata_offset = 0;
1477         uint32_t fourcc = 0;
1478         AVIOContext b;
1479
1480         /* Apply some sanity checks. */
1481         if (track->type != MATROSKA_TRACK_TYPE_VIDEO &&
1482             track->type != MATROSKA_TRACK_TYPE_AUDIO &&
1483             track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
1484             av_log(matroska->ctx, AV_LOG_INFO,
1485                    "Unknown or unsupported track type %"PRIu64"\n",
1486                    track->type);
1487             continue;
1488         }
1489         if (track->codec_id == NULL)
1490             continue;
1491
1492         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1493             if (!track->default_duration && track->video.frame_rate > 0)
1494                 track->default_duration = 1000000000/track->video.frame_rate;
1495             if (!track->video.display_width)
1496                 track->video.display_width = track->video.pixel_width;
1497             if (!track->video.display_height)
1498                 track->video.display_height = track->video.pixel_height;
1499             if (track->video.color_space.size == 4)
1500                 fourcc = AV_RL32(track->video.color_space.data);
1501         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1502             if (!track->audio.out_samplerate)
1503                 track->audio.out_samplerate = track->audio.samplerate;
1504         }
1505         if (encodings_list->nb_elem > 1) {
1506             av_log(matroska->ctx, AV_LOG_ERROR,
1507                    "Multiple combined encodings not supported");
1508         } else if (encodings_list->nb_elem == 1) {
1509             if (encodings[0].type ||
1510                 (encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP &&
1511 #if CONFIG_ZLIB
1512                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_ZLIB &&
1513 #endif
1514 #if CONFIG_BZLIB
1515                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_BZLIB &&
1516 #endif
1517                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_LZO)) {
1518                 encodings[0].scope = 0;
1519                 av_log(matroska->ctx, AV_LOG_ERROR,
1520                        "Unsupported encoding type");
1521             } else if (track->codec_priv.size && encodings[0].scope&2) {
1522                 uint8_t *codec_priv = track->codec_priv.data;
1523                 int offset = matroska_decode_buffer(&track->codec_priv.data,
1524                                                     &track->codec_priv.size,
1525                                                     track);
1526                 if (offset < 0) {
1527                     track->codec_priv.data = NULL;
1528                     track->codec_priv.size = 0;
1529                     av_log(matroska->ctx, AV_LOG_ERROR,
1530                            "Failed to decode codec private data\n");
1531                 } else if (offset > 0) {
1532                     track->codec_priv.data = av_malloc(track->codec_priv.size + offset);
1533                     memcpy(track->codec_priv.data,
1534                            encodings[0].compression.settings.data, offset);
1535                     memcpy(track->codec_priv.data+offset, codec_priv,
1536                            track->codec_priv.size);
1537                     track->codec_priv.size += offset;
1538                 }
1539                 if (codec_priv != track->codec_priv.data)
1540                     av_free(codec_priv);
1541             }
1542         }
1543
1544         for(j=0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++){
1545             if(!strncmp(ff_mkv_codec_tags[j].str, track->codec_id,
1546                         strlen(ff_mkv_codec_tags[j].str))){
1547                 codec_id= ff_mkv_codec_tags[j].id;
1548                 break;
1549             }
1550         }
1551
1552         st = track->stream = avformat_new_stream(s, NULL);
1553         if (st == NULL)
1554             return AVERROR(ENOMEM);
1555
1556         if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC")
1557             && track->codec_priv.size >= 40
1558             && track->codec_priv.data != NULL) {
1559             track->ms_compat = 1;
1560             fourcc = AV_RL32(track->codec_priv.data + 16);
1561             codec_id = ff_codec_get_id(ff_codec_bmp_tags, fourcc);
1562             extradata_offset = 40;
1563         } else if (!strcmp(track->codec_id, "A_MS/ACM")
1564                    && track->codec_priv.size >= 14
1565                    && track->codec_priv.data != NULL) {
1566             int ret;
1567             ffio_init_context(&b, track->codec_priv.data, track->codec_priv.size,
1568                           AVIO_FLAG_READ, NULL, NULL, NULL, NULL);
1569             ret = ff_get_wav_header(&b, st->codec, track->codec_priv.size);
1570             if (ret < 0)
1571                 return ret;
1572             codec_id = st->codec->codec_id;
1573             extradata_offset = FFMIN(track->codec_priv.size, 18);
1574         } else if (!strcmp(track->codec_id, "V_QUICKTIME")
1575                    && (track->codec_priv.size >= 86)
1576                    && (track->codec_priv.data != NULL)) {
1577             fourcc = AV_RL32(track->codec_priv.data);
1578             codec_id = ff_codec_get_id(ff_codec_movvideo_tags, fourcc);
1579         } else if (codec_id == CODEC_ID_PCM_S16BE) {
1580             switch (track->audio.bitdepth) {
1581             case  8:  codec_id = CODEC_ID_PCM_U8;     break;
1582             case 24:  codec_id = CODEC_ID_PCM_S24BE;  break;
1583             case 32:  codec_id = CODEC_ID_PCM_S32BE;  break;
1584             }
1585         } else if (codec_id == CODEC_ID_PCM_S16LE) {
1586             switch (track->audio.bitdepth) {
1587             case  8:  codec_id = CODEC_ID_PCM_U8;     break;
1588             case 24:  codec_id = CODEC_ID_PCM_S24LE;  break;
1589             case 32:  codec_id = CODEC_ID_PCM_S32LE;  break;
1590             }
1591         } else if (codec_id==CODEC_ID_PCM_F32LE && track->audio.bitdepth==64) {
1592             codec_id = CODEC_ID_PCM_F64LE;
1593         } else if (codec_id == CODEC_ID_AAC && !track->codec_priv.size) {
1594             int profile = matroska_aac_profile(track->codec_id);
1595             int sri = matroska_aac_sri(track->audio.samplerate);
1596             extradata = av_mallocz(5 + FF_INPUT_BUFFER_PADDING_SIZE);
1597             if (extradata == NULL)
1598                 return AVERROR(ENOMEM);
1599             extradata[0] = (profile << 3) | ((sri&0x0E) >> 1);
1600             extradata[1] = ((sri&0x01) << 7) | (track->audio.channels<<3);
1601             if (strstr(track->codec_id, "SBR")) {
1602                 sri = matroska_aac_sri(track->audio.out_samplerate);
1603                 extradata[2] = 0x56;
1604                 extradata[3] = 0xE5;
1605                 extradata[4] = 0x80 | (sri<<3);
1606                 extradata_size = 5;
1607             } else
1608                 extradata_size = 2;
1609         } else if (codec_id == CODEC_ID_TTA) {
1610             extradata_size = 30;
1611             extradata = av_mallocz(extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
1612             if (extradata == NULL)
1613                 return AVERROR(ENOMEM);
1614             ffio_init_context(&b, extradata, extradata_size, 1,
1615                           NULL, NULL, NULL, NULL);
1616             avio_write(&b, "TTA1", 4);
1617             avio_wl16(&b, 1);
1618             avio_wl16(&b, track->audio.channels);
1619             avio_wl16(&b, track->audio.bitdepth);
1620             avio_wl32(&b, track->audio.out_samplerate);
1621             avio_wl32(&b, matroska->ctx->duration * track->audio.out_samplerate);
1622         } else if (codec_id == CODEC_ID_RV10 || codec_id == CODEC_ID_RV20 ||
1623                    codec_id == CODEC_ID_RV30 || codec_id == CODEC_ID_RV40) {
1624             extradata_offset = 26;
1625         } else if (codec_id == CODEC_ID_RA_144) {
1626             track->audio.out_samplerate = 8000;
1627             track->audio.channels = 1;
1628         } else if ((codec_id == CODEC_ID_RA_288 || codec_id == CODEC_ID_COOK ||
1629                     codec_id == CODEC_ID_ATRAC3 || codec_id == CODEC_ID_SIPR)
1630                     && track->codec_priv.data) {
1631             int flavor;
1632
1633             ffio_init_context(&b, track->codec_priv.data,track->codec_priv.size,
1634                           0, NULL, NULL, NULL, NULL);
1635             avio_skip(&b, 22);
1636             flavor                       = avio_rb16(&b);
1637             track->audio.coded_framesize = avio_rb32(&b);
1638             avio_skip(&b, 12);
1639             track->audio.sub_packet_h    = avio_rb16(&b);
1640             track->audio.frame_size      = avio_rb16(&b);
1641             track->audio.sub_packet_size = avio_rb16(&b);
1642             track->audio.buf = av_malloc(track->audio.frame_size * track->audio.sub_packet_h);
1643             if (codec_id == CODEC_ID_RA_288) {
1644                 st->codec->block_align = track->audio.coded_framesize;
1645                 track->codec_priv.size = 0;
1646             } else {
1647                 if (codec_id == CODEC_ID_SIPR && flavor < 4) {
1648                     const int sipr_bit_rate[4] = { 6504, 8496, 5000, 16000 };
1649                     track->audio.sub_packet_size = ff_sipr_subpk_size[flavor];
1650                     st->codec->bit_rate = sipr_bit_rate[flavor];
1651                 }
1652                 st->codec->block_align = track->audio.sub_packet_size;
1653                 extradata_offset = 78;
1654             }
1655         }
1656         track->codec_priv.size -= extradata_offset;
1657
1658         if (codec_id == CODEC_ID_NONE)
1659             av_log(matroska->ctx, AV_LOG_INFO,
1660                    "Unknown/unsupported CodecID %s.\n", track->codec_id);
1661
1662         if (track->time_scale < 0.01)
1663             track->time_scale = 1.0;
1664         avpriv_set_pts_info(st, 64, matroska->time_scale*track->time_scale, 1000*1000*1000); /* 64 bit pts in ns */
1665
1666         st->codec->codec_id = codec_id;
1667         st->start_time = 0;
1668         if (strcmp(track->language, "und"))
1669             av_dict_set(&st->metadata, "language", track->language, 0);
1670         av_dict_set(&st->metadata, "title", track->name, 0);
1671
1672         if (track->flag_default)
1673             st->disposition |= AV_DISPOSITION_DEFAULT;
1674         if (track->flag_forced)
1675             st->disposition |= AV_DISPOSITION_FORCED;
1676
1677         if (!st->codec->extradata) {
1678             if(extradata){
1679                 st->codec->extradata = extradata;
1680                 st->codec->extradata_size = extradata_size;
1681             } else if(track->codec_priv.data && track->codec_priv.size > 0){
1682                 st->codec->extradata = av_mallocz(track->codec_priv.size +
1683                                                   FF_INPUT_BUFFER_PADDING_SIZE);
1684                 if(st->codec->extradata == NULL)
1685                     return AVERROR(ENOMEM);
1686                 st->codec->extradata_size = track->codec_priv.size;
1687                 memcpy(st->codec->extradata,
1688                        track->codec_priv.data + extradata_offset,
1689                        track->codec_priv.size);
1690             }
1691         }
1692
1693         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1694             MatroskaTrackPlane *planes = track->operation.combine_planes.elem;
1695
1696             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
1697             st->codec->codec_tag  = fourcc;
1698             st->codec->width  = track->video.pixel_width;
1699             st->codec->height = track->video.pixel_height;
1700             av_reduce(&st->sample_aspect_ratio.num,
1701                       &st->sample_aspect_ratio.den,
1702                       st->codec->height * track->video.display_width,
1703                       st->codec-> width * track->video.display_height,
1704                       255);
1705             st->need_parsing = AVSTREAM_PARSE_HEADERS;
1706             if (track->default_duration) {
1707                 av_reduce(&st->r_frame_rate.num, &st->r_frame_rate.den,
1708                           1000000000, track->default_duration, 30000);
1709                 st->avg_frame_rate = st->r_frame_rate;
1710             }
1711
1712             /* export stereo mode flag as metadata tag */
1713             if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREO_MODE_COUNT)
1714                 av_dict_set(&st->metadata, "stereo_mode", matroska_video_stereo_mode[track->video.stereo_mode], 0);
1715
1716             /* if we have virtual track, mark the real tracks */
1717             for (j=0; j < track->operation.combine_planes.nb_elem; j++) {
1718                 char buf[32];
1719                 if (planes[j].type >= MATROSKA_VIDEO_STEREO_PLANE_COUNT)
1720                     continue;
1721                 snprintf(buf, sizeof(buf), "%s_%d",
1722                          matroska_video_stereo_plane[planes[j].type], i);
1723                 for (k=0; k < matroska->tracks.nb_elem; k++)
1724                     if (planes[j].uid == tracks[k].uid) {
1725                         av_dict_set(&s->streams[k]->metadata,
1726                                     "stereo_mode", buf, 0);
1727                         break;
1728                     }
1729             }
1730         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1731             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
1732             st->codec->sample_rate = track->audio.out_samplerate;
1733             st->codec->channels = track->audio.channels;
1734             if (st->codec->codec_id != CODEC_ID_AAC)
1735             st->need_parsing = AVSTREAM_PARSE_HEADERS;
1736         } else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
1737             st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
1738             if (st->codec->codec_id == CODEC_ID_SSA)
1739                 matroska->contains_ssa = 1;
1740         }
1741     }
1742
1743     attachements = attachements_list->elem;
1744     for (j=0; j<attachements_list->nb_elem; j++) {
1745         if (!(attachements[j].filename && attachements[j].mime &&
1746               attachements[j].bin.data && attachements[j].bin.size > 0)) {
1747             av_log(matroska->ctx, AV_LOG_ERROR, "incomplete attachment\n");
1748         } else {
1749             AVStream *st = avformat_new_stream(s, NULL);
1750             if (st == NULL)
1751                 break;
1752             av_dict_set(&st->metadata, "filename",attachements[j].filename, 0);
1753             av_dict_set(&st->metadata, "mimetype", attachements[j].mime, 0);
1754             st->codec->codec_id = CODEC_ID_NONE;
1755             st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
1756             st->codec->extradata  = av_malloc(attachements[j].bin.size + FF_INPUT_BUFFER_PADDING_SIZE);
1757             if(st->codec->extradata == NULL)
1758                 break;
1759             st->codec->extradata_size = attachements[j].bin.size;
1760             memcpy(st->codec->extradata, attachements[j].bin.data, attachements[j].bin.size);
1761
1762             for (i=0; ff_mkv_mime_tags[i].id != CODEC_ID_NONE; i++) {
1763                 if (!strncmp(ff_mkv_mime_tags[i].str, attachements[j].mime,
1764                              strlen(ff_mkv_mime_tags[i].str))) {
1765                     st->codec->codec_id = ff_mkv_mime_tags[i].id;
1766                     break;
1767                 }
1768             }
1769             attachements[j].stream = st;
1770         }
1771     }
1772
1773     chapters = chapters_list->elem;
1774     for (i=0; i<chapters_list->nb_elem; i++)
1775         if (chapters[i].start != AV_NOPTS_VALUE && chapters[i].uid
1776             && (max_start==0 || chapters[i].start > max_start)) {
1777             chapters[i].chapter =
1778             avpriv_new_chapter(s, chapters[i].uid, (AVRational){1, 1000000000},
1779                            chapters[i].start, chapters[i].end,
1780                            chapters[i].title);
1781             av_dict_set(&chapters[i].chapter->metadata,
1782                              "title", chapters[i].title, 0);
1783             max_start = chapters[i].start;
1784         }
1785
1786     matroska_add_index_entries(matroska);
1787
1788     matroska_convert_tags(s);
1789
1790     return 0;
1791 }
1792
1793 /*
1794  * Put one packet in an application-supplied AVPacket struct.
1795  * Returns 0 on success or -1 on failure.
1796  */
1797 static int matroska_deliver_packet(MatroskaDemuxContext *matroska,
1798                                    AVPacket *pkt)
1799 {
1800     if (matroska->num_packets > 0) {
1801         memcpy(pkt, matroska->packets[0], sizeof(AVPacket));
1802         av_free(matroska->packets[0]);
1803         if (matroska->num_packets > 1) {
1804             void *newpackets;
1805             memmove(&matroska->packets[0], &matroska->packets[1],
1806                     (matroska->num_packets - 1) * sizeof(AVPacket *));
1807             newpackets = av_realloc(matroska->packets,
1808                             (matroska->num_packets - 1) * sizeof(AVPacket *));
1809             if (newpackets)
1810                 matroska->packets = newpackets;
1811         } else {
1812             av_freep(&matroska->packets);
1813             matroska->prev_pkt = NULL;
1814         }
1815         matroska->num_packets--;
1816         return 0;
1817     }
1818
1819     return -1;
1820 }
1821
1822 /*
1823  * Free all packets in our internal queue.
1824  */
1825 static void matroska_clear_queue(MatroskaDemuxContext *matroska)
1826 {
1827     if (matroska->packets) {
1828         int n;
1829         for (n = 0; n < matroska->num_packets; n++) {
1830             av_free_packet(matroska->packets[n]);
1831             av_free(matroska->packets[n]);
1832         }
1833         av_freep(&matroska->packets);
1834         matroska->num_packets = 0;
1835     }
1836 }
1837
1838 static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
1839                                 int size, int64_t pos, uint64_t cluster_time,
1840                                 uint64_t duration, int is_keyframe,
1841                                 int64_t cluster_pos)
1842 {
1843     uint64_t timecode = AV_NOPTS_VALUE;
1844     MatroskaTrack *track;
1845     int res = 0;
1846     AVStream *st;
1847     AVPacket *pkt;
1848     int16_t block_time;
1849     uint32_t *lace_size = NULL;
1850     int n, flags, laces = 0;
1851     uint64_t num;
1852
1853     if ((n = matroska_ebmlnum_uint(matroska, data, size, &num)) < 0) {
1854         av_log(matroska->ctx, AV_LOG_ERROR, "EBML block data error\n");
1855         return n;
1856     }
1857     data += n;
1858     size -= n;
1859
1860     track = matroska_find_track_by_num(matroska, num);
1861     if (!track || !track->stream) {
1862         av_log(matroska->ctx, AV_LOG_INFO,
1863                "Invalid stream %"PRIu64" or size %u\n", num, size);
1864         return AVERROR_INVALIDDATA;
1865     } else if (size <= 3)
1866         return 0;
1867     st = track->stream;
1868     if (st->discard >= AVDISCARD_ALL)
1869         return res;
1870     av_assert1(duration != AV_NOPTS_VALUE);
1871     if (!duration)
1872         duration = track->default_duration / matroska->time_scale;
1873
1874     block_time = AV_RB16(data);
1875     data += 2;
1876     flags = *data++;
1877     size -= 3;
1878     if (is_keyframe == -1)
1879         is_keyframe = flags & 0x80 ? AV_PKT_FLAG_KEY : 0;
1880
1881     if (cluster_time != (uint64_t)-1
1882         && (block_time >= 0 || cluster_time >= -block_time)) {
1883         timecode = cluster_time + block_time;
1884         if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE
1885             && timecode < track->end_timecode)
1886             is_keyframe = 0;  /* overlapping subtitles are not key frame */
1887         if (is_keyframe)
1888             av_add_index_entry(st, cluster_pos, timecode, 0,0,AVINDEX_KEYFRAME);
1889         track->end_timecode = FFMAX(track->end_timecode, timecode+duration);
1890     }
1891
1892     if (matroska->skip_to_keyframe && track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
1893         if (timecode < matroska->skip_to_timecode)
1894             return res;
1895         if (!st->skip_to_keyframe) {
1896             av_log(matroska->ctx, AV_LOG_ERROR, "File is broken, keyframes not correctly marked!\n");
1897             matroska->skip_to_keyframe = 0;
1898         }
1899         if (is_keyframe)
1900             matroska->skip_to_keyframe = 0;
1901     }
1902
1903     switch ((flags & 0x06) >> 1) {
1904         case 0x0: /* no lacing */
1905             laces = 1;
1906             lace_size = av_mallocz(sizeof(int));
1907             lace_size[0] = size;
1908             break;
1909
1910         case 0x1: /* Xiph lacing */
1911         case 0x2: /* fixed-size lacing */
1912         case 0x3: /* EBML lacing */
1913             av_assert0(size>0); // size <=3 is checked before size-=3 above
1914             laces = (*data) + 1;
1915             data += 1;
1916             size -= 1;
1917             lace_size = av_mallocz(laces * sizeof(int));
1918
1919             switch ((flags & 0x06) >> 1) {
1920                 case 0x1: /* Xiph lacing */ {
1921                     uint8_t temp;
1922                     uint32_t total = 0;
1923                     for (n = 0; res == 0 && n < laces - 1; n++) {
1924                         while (1) {
1925                             if (size == 0) {
1926                                 res = -1;
1927                                 break;
1928                             }
1929                             temp = *data;
1930                             lace_size[n] += temp;
1931                             data += 1;
1932                             size -= 1;
1933                             if (temp != 0xff)
1934                                 break;
1935                         }
1936                         total += lace_size[n];
1937                     }
1938                     lace_size[n] = size - total;
1939                     break;
1940                 }
1941
1942                 case 0x2: /* fixed-size lacing */
1943                     for (n = 0; n < laces; n++)
1944                         lace_size[n] = size / laces;
1945                     break;
1946
1947                 case 0x3: /* EBML lacing */ {
1948                     uint32_t total;
1949                     n = matroska_ebmlnum_uint(matroska, data, size, &num);
1950                     if (n < 0) {
1951                         av_log(matroska->ctx, AV_LOG_INFO,
1952                                "EBML block data error\n");
1953                         break;
1954                     }
1955                     data += n;
1956                     size -= n;
1957                     total = lace_size[0] = num;
1958                     for (n = 1; res == 0 && n < laces - 1; n++) {
1959                         int64_t snum;
1960                         int r;
1961                         r = matroska_ebmlnum_sint(matroska, data, size, &snum);
1962                         if (r < 0) {
1963                             av_log(matroska->ctx, AV_LOG_INFO,
1964                                    "EBML block data error\n");
1965                             break;
1966                         }
1967                         data += r;
1968                         size -= r;
1969                         lace_size[n] = lace_size[n - 1] + snum;
1970                         total += lace_size[n];
1971                     }
1972                     lace_size[laces - 1] = size - total;
1973                     break;
1974                 }
1975             }
1976             break;
1977     }
1978
1979     if (res == 0) {
1980         for (n = 0; n < laces; n++) {
1981             if (lace_size[n] > size) {
1982                 av_log(matroska->ctx, AV_LOG_ERROR, "Invalid packet size\n");
1983                 break;
1984             }
1985
1986             if ((st->codec->codec_id == CODEC_ID_RA_288 ||
1987                  st->codec->codec_id == CODEC_ID_COOK ||
1988                  st->codec->codec_id == CODEC_ID_SIPR ||
1989                  st->codec->codec_id == CODEC_ID_ATRAC3) &&
1990                  st->codec->block_align && track->audio.sub_packet_size) {
1991                 int a = st->codec->block_align;
1992                 int sps = track->audio.sub_packet_size;
1993                 int cfs = track->audio.coded_framesize;
1994                 int h = track->audio.sub_packet_h;
1995                 int y = track->audio.sub_packet_cnt;
1996                 int w = track->audio.frame_size;
1997                 int x;
1998
1999                 if (!track->audio.pkt_cnt) {
2000                     if (track->audio.sub_packet_cnt == 0)
2001                         track->audio.buf_timecode = timecode;
2002                     if (st->codec->codec_id == CODEC_ID_RA_288) {
2003                         if (size < cfs * h / 2) {
2004                             av_log(matroska->ctx, AV_LOG_ERROR,
2005                                    "Corrupt int4 RM-style audio packet size\n");
2006                             res = AVERROR_INVALIDDATA;
2007                             goto end;
2008                         }
2009                         for (x=0; x<h/2; x++)
2010                             memcpy(track->audio.buf+x*2*w+y*cfs,
2011                                    data+x*cfs, cfs);
2012                     } else if (st->codec->codec_id == CODEC_ID_SIPR) {
2013                         if (size < w) {
2014                             av_log(matroska->ctx, AV_LOG_ERROR,
2015                                    "Corrupt sipr RM-style audio packet size\n");
2016                             res = AVERROR_INVALIDDATA;
2017                             goto end;
2018                         }
2019                         memcpy(track->audio.buf + y*w, data, w);
2020                     } else {
2021                         if (size < sps * w / sps) {
2022                             av_log(matroska->ctx, AV_LOG_ERROR,
2023                                    "Corrupt generic RM-style audio packet size\n");
2024                             res = AVERROR_INVALIDDATA;
2025                             goto end;
2026                         }
2027                         for (x=0; x<w/sps; x++)
2028                             memcpy(track->audio.buf+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), data+x*sps, sps);
2029                     }
2030
2031                     if (++track->audio.sub_packet_cnt >= h) {
2032                         if (st->codec->codec_id == CODEC_ID_SIPR)
2033                             ff_rm_reorder_sipr_data(track->audio.buf, h, w);
2034                         track->audio.sub_packet_cnt = 0;
2035                         track->audio.pkt_cnt = h*w / a;
2036                     }
2037                 }
2038                 while (track->audio.pkt_cnt) {
2039                     pkt = av_mallocz(sizeof(AVPacket));
2040                     av_new_packet(pkt, a);
2041                     memcpy(pkt->data, track->audio.buf
2042                            + a * (h*w / a - track->audio.pkt_cnt--), a);
2043                     pkt->pts = track->audio.buf_timecode;
2044                     track->audio.buf_timecode = AV_NOPTS_VALUE;
2045                     pkt->pos = pos;
2046                     pkt->stream_index = st->index;
2047                     dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
2048                 }
2049             } else {
2050                 MatroskaTrackEncoding *encodings = track->encodings.elem;
2051                 int offset = 0;
2052                 uint32_t pkt_size = lace_size[n];
2053                 uint8_t *pkt_data = data;
2054
2055                 if (encodings && encodings->scope & 1) {
2056                     offset = matroska_decode_buffer(&pkt_data,&pkt_size, track);
2057                     if (offset < 0)
2058                         continue;
2059                     av_assert0(offset + pkt_size >= pkt_size);
2060                 }
2061
2062                 pkt = av_mallocz(sizeof(AVPacket));
2063                 /* XXX: prevent data copy... */
2064                 if (av_new_packet(pkt, pkt_size+offset) < 0) {
2065                     av_free(pkt);
2066                     res = AVERROR(ENOMEM);
2067                     break;
2068                 }
2069                 if (offset)
2070                     memcpy (pkt->data, encodings->compression.settings.data, offset);
2071                 memcpy (pkt->data+offset, pkt_data, pkt_size);
2072
2073                 if (pkt_data != data)
2074                     av_free(pkt_data);
2075
2076                 if (n == 0)
2077                     pkt->flags = is_keyframe;
2078                 pkt->stream_index = st->index;
2079
2080                 if (track->ms_compat)
2081                     pkt->dts = timecode;
2082                 else
2083                     pkt->pts = timecode;
2084                 pkt->pos = pos;
2085                 if (st->codec->codec_id == CODEC_ID_TEXT)
2086                     pkt->convergence_duration = duration;
2087                 else if (track->type != MATROSKA_TRACK_TYPE_SUBTITLE)
2088                     pkt->duration = duration;
2089
2090                 if (st->codec->codec_id == CODEC_ID_SSA)
2091                     matroska_fix_ass_packet(matroska, pkt, duration);
2092
2093                 if (matroska->prev_pkt &&
2094                     timecode != AV_NOPTS_VALUE &&
2095                     matroska->prev_pkt->pts == timecode &&
2096                     matroska->prev_pkt->stream_index == st->index &&
2097                     st->codec->codec_id == CODEC_ID_SSA)
2098                     matroska_merge_packets(matroska->prev_pkt, pkt);
2099                 else {
2100                     dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
2101                     matroska->prev_pkt = pkt;
2102                 }
2103             }
2104
2105             if (timecode != AV_NOPTS_VALUE)
2106                 timecode = duration ? timecode + duration : AV_NOPTS_VALUE;
2107             data += lace_size[n];
2108             size -= lace_size[n];
2109         }
2110     }
2111
2112 end:
2113     av_free(lace_size);
2114     return res;
2115 }
2116
2117 static int matroska_parse_cluster_incremental(MatroskaDemuxContext *matroska)
2118 {
2119     EbmlList *blocks_list;
2120     MatroskaBlock *blocks;
2121     int i, res;
2122     res = ebml_parse(matroska,
2123                      matroska_cluster_incremental_parsing,
2124                      &matroska->current_cluster);
2125     if (res == 1) {
2126         /* New Cluster */
2127         if (matroska->current_cluster_pos)
2128             ebml_level_end(matroska);
2129         ebml_free(matroska_cluster, &matroska->current_cluster);
2130         memset(&matroska->current_cluster, 0, sizeof(MatroskaCluster));
2131         matroska->current_cluster_num_blocks = 0;
2132         matroska->current_cluster_pos = avio_tell(matroska->ctx->pb);
2133         matroska->prev_pkt = NULL;
2134         /* sizeof the ID which was already read */
2135         if (matroska->current_id)
2136             matroska->current_cluster_pos -= 4;
2137         res = ebml_parse(matroska,
2138                          matroska_clusters_incremental,
2139                          &matroska->current_cluster);
2140         /* Try parsing the block again. */
2141         if (res == 1)
2142             res = ebml_parse(matroska,
2143                              matroska_cluster_incremental_parsing,
2144                              &matroska->current_cluster);
2145     }
2146
2147     if (!res &&
2148         matroska->current_cluster_num_blocks <
2149             matroska->current_cluster.blocks.nb_elem) {
2150         blocks_list = &matroska->current_cluster.blocks;
2151         blocks = blocks_list->elem;
2152
2153         matroska->current_cluster_num_blocks = blocks_list->nb_elem;
2154         i = blocks_list->nb_elem - 1;
2155         if (blocks[i].bin.size > 0 && blocks[i].bin.data) {
2156             int is_keyframe = blocks[i].non_simple ? !blocks[i].reference : -1;
2157             if (!blocks[i].non_simple)
2158                 blocks[i].duration = 0;
2159             res = matroska_parse_block(matroska,
2160                                        blocks[i].bin.data, blocks[i].bin.size,
2161                                        blocks[i].bin.pos,
2162                                        matroska->current_cluster.timecode,
2163                                        blocks[i].duration, is_keyframe,
2164                                        matroska->current_cluster_pos);
2165         }
2166     }
2167
2168     if (res < 0)  matroska->done = 1;
2169     return res;
2170 }
2171
2172 static int matroska_parse_cluster(MatroskaDemuxContext *matroska)
2173 {
2174     MatroskaCluster cluster = { 0 };
2175     EbmlList *blocks_list;
2176     MatroskaBlock *blocks;
2177     int i, res;
2178     int64_t pos;
2179     if (!matroska->contains_ssa)
2180         return matroska_parse_cluster_incremental(matroska);
2181     pos = avio_tell(matroska->ctx->pb);
2182     matroska->prev_pkt = NULL;
2183     if (matroska->current_id)
2184         pos -= 4;  /* sizeof the ID which was already read */
2185     res = ebml_parse(matroska, matroska_clusters, &cluster);
2186     blocks_list = &cluster.blocks;
2187     blocks = blocks_list->elem;
2188     for (i=0; i<blocks_list->nb_elem; i++)
2189         if (blocks[i].bin.size > 0 && blocks[i].bin.data) {
2190             int is_keyframe = blocks[i].non_simple ? !blocks[i].reference : -1;
2191             res=matroska_parse_block(matroska,
2192                                      blocks[i].bin.data, blocks[i].bin.size,
2193                                      blocks[i].bin.pos,  cluster.timecode,
2194                                      blocks[i].duration, is_keyframe,
2195                                      pos);
2196         }
2197     ebml_free(matroska_cluster, &cluster);
2198     return res;
2199 }
2200
2201 static int matroska_read_packet(AVFormatContext *s, AVPacket *pkt)
2202 {
2203     MatroskaDemuxContext *matroska = s->priv_data;
2204
2205     while (matroska_deliver_packet(matroska, pkt)) {
2206         int64_t pos = avio_tell(matroska->ctx->pb);
2207         if (matroska->done)
2208             return AVERROR_EOF;
2209         if (matroska_parse_cluster(matroska) < 0)
2210             matroska_resync(matroska, pos);
2211     }
2212
2213     return 0;
2214 }
2215
2216 static int matroska_read_seek(AVFormatContext *s, int stream_index,
2217                               int64_t timestamp, int flags)
2218 {
2219     MatroskaDemuxContext *matroska = s->priv_data;
2220     MatroskaTrack *tracks = matroska->tracks.elem;
2221     AVStream *st = s->streams[stream_index];
2222     int i, index, index_sub, index_min;
2223
2224     /* Parse the CUES now since we need the index data to seek. */
2225     if (matroska->cues_parsing_deferred > 0) {
2226         matroska->cues_parsing_deferred = 0;
2227         matroska_parse_cues(matroska);
2228     }
2229
2230     if (!st->nb_index_entries)
2231         goto err;
2232     timestamp = FFMAX(timestamp, st->index_entries[0].timestamp);
2233
2234     if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
2235         avio_seek(s->pb, st->index_entries[st->nb_index_entries-1].pos, SEEK_SET);
2236         matroska->current_id = 0;
2237         while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
2238             matroska->prev_pkt = NULL;
2239             matroska_clear_queue(matroska);
2240             if (matroska_parse_cluster(matroska) < 0)
2241                 break;
2242         }
2243     }
2244
2245     matroska_clear_queue(matroska);
2246     if (index < 0 || (matroska->cues_parsing_deferred < 0 && index == st->nb_index_entries - 1))
2247         goto err;
2248
2249     index_min = index;
2250     for (i=0; i < matroska->tracks.nb_elem; i++) {
2251         tracks[i].audio.pkt_cnt = 0;
2252         tracks[i].audio.sub_packet_cnt = 0;
2253         tracks[i].audio.buf_timecode = AV_NOPTS_VALUE;
2254         tracks[i].end_timecode = 0;
2255         if (tracks[i].type == MATROSKA_TRACK_TYPE_SUBTITLE
2256             && !tracks[i].stream->discard != AVDISCARD_ALL) {
2257             index_sub = av_index_search_timestamp(tracks[i].stream, st->index_entries[index].timestamp, AVSEEK_FLAG_BACKWARD);
2258             if (index_sub >= 0
2259                 && st->index_entries[index_sub].pos < st->index_entries[index_min].pos
2260                 && st->index_entries[index].timestamp - st->index_entries[index_sub].timestamp < 30000000000/matroska->time_scale)
2261                 index_min = index_sub;
2262         }
2263     }
2264
2265     avio_seek(s->pb, st->index_entries[index_min].pos, SEEK_SET);
2266     matroska->current_id = 0;
2267     st->skip_to_keyframe =
2268     matroska->skip_to_keyframe = !(flags & AVSEEK_FLAG_ANY);
2269     matroska->skip_to_timecode = st->index_entries[index].timestamp;
2270     matroska->done = 0;
2271     matroska->num_levels = 0;
2272     ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
2273     return 0;
2274 err:
2275     // slightly hackish but allows proper fallback to
2276     // the generic seeking code.
2277     matroska_clear_queue(matroska);
2278     matroska->current_id = 0;
2279     st->skip_to_keyframe =
2280     matroska->skip_to_keyframe = 0;
2281     matroska->done = 0;
2282     matroska->num_levels = 0;
2283     return -1;
2284 }
2285
2286 static int matroska_read_close(AVFormatContext *s)
2287 {
2288     MatroskaDemuxContext *matroska = s->priv_data;
2289     MatroskaTrack *tracks = matroska->tracks.elem;
2290     int n;
2291
2292     matroska_clear_queue(matroska);
2293
2294     for (n=0; n < matroska->tracks.nb_elem; n++)
2295         if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)
2296             av_free(tracks[n].audio.buf);
2297     ebml_free(matroska_cluster, &matroska->current_cluster);
2298     ebml_free(matroska_segment, matroska);
2299
2300     return 0;
2301 }
2302
2303 AVInputFormat ff_matroska_demuxer = {
2304     .name           = "matroska,webm",
2305     .long_name      = NULL_IF_CONFIG_SMALL("Matroska/WebM file format"),
2306     .priv_data_size = sizeof(MatroskaDemuxContext),
2307     .read_probe     = matroska_probe,
2308     .read_header    = matroska_read_header,
2309     .read_packet    = matroska_read_packet,
2310     .read_close     = matroska_read_close,
2311     .read_seek      = matroska_read_seek,
2312 };