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

   1 /*
   2  * Matroska file demuxer
   3  * Copyright (c) 2003-2008 The FFmpeg Project
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * Matroska file demuxer
  25  * @author Ronald Bultje <rbultje@ronald.bitfreak.net>
  26  * @author with a little help from Moritz Bunkus <moritz@bunkus.org>
  27  * @author totally reworked by Aurelien Jacobs <aurel@gnuage.org>
  28  * @see specs available on the Matroska project page: http://www.matroska.org/
  29  */
  30
  31 #include <stdio.h>
  32 #include "avformat.h"
  33 #include "internal.h"
  34 #include "avio_internal.h"
  35 /* For ff_codec_get_id(). */
  36 #include "riff.h"
  37 #include "isom.h"
  38 #include "rm.h"
  39 #include "matroska.h"
  40 #include "libavcodec/mpeg4audio.h"
  41 #include "libavutil/intfloat.h"
  42 #include "libavutil/intreadwrite.h"
  43 #include "libavutil/avstring.h"
  44 #include "libavutil/lzo.h"
  45 #include "libavutil/dict.h"
  46 #if CONFIG_ZLIB
  47 #include <zlib.h>
  48 #endif
  49 #if CONFIG_BZLIB
  50 #include <bzlib.h>
  51 #endif
  52
  53 typedef enum {
  54     EBML_NONE,
  55     EBML_UINT,
  56     EBML_FLOAT,
  57     EBML_STR,
  58     EBML_UTF8,
  59     EBML_BIN,
  60     EBML_NEST,
  61     EBML_PASS,
  62     EBML_STOP,
  63     EBML_TYPE_COUNT
  64 } EbmlType;
  65
  66 typedef const struct EbmlSyntax {
  67     uint32_t id;
  68     EbmlType type;
  69     int list_elem_size;
  70     int data_offset;
  71     union {
  72         uint64_t    u;
  73         double      f;
  74         const char *s;
  75         const struct EbmlSyntax *n;
  76     } def;
  77 } EbmlSyntax;
  78
  79 typedef struct {
  80     int nb_elem;
  81     void *elem;
  82 } EbmlList;
  83
  84 typedef struct {
  85     int      size;
  86     uint8_t *data;
  87     int64_t  pos;
  88 } EbmlBin;
  89
  90 typedef struct {
  91     uint64_t version;
  92     uint64_t max_size;
  93     uint64_t id_length;
  94     char    *doctype;
  95     uint64_t doctype_version;
  96 } Ebml;
  97
  98 typedef struct {
  99     uint64_t algo;
 100     EbmlBin  settings;
 101 } MatroskaTrackCompression;
 102
 103 typedef struct {
 104     uint64_t scope;
 105     uint64_t type;
 106     MatroskaTrackCompression compression;
 107 } MatroskaTrackEncoding;
 108
 109 typedef struct {
 110     double   frame_rate;
 111     uint64_t display_width;
 112     uint64_t display_height;
 113     uint64_t pixel_width;
 114     uint64_t pixel_height;
 115     EbmlBin color_space;
 116     uint64_t stereo_mode;
 117 } MatroskaTrackVideo;
 118
 119 typedef struct {
 120     double   samplerate;
 121     double   out_samplerate;
 122     uint64_t bitdepth;
 123     uint64_t channels;
 124
 125     /* real audio header (extracted from extradata) */
 126     int      coded_framesize;
 127     int      sub_packet_h;
 128     int      frame_size;
 129     int      sub_packet_size;
 130     int      sub_packet_cnt;
 131     int      pkt_cnt;
 132     uint64_t buf_timecode;
 133     uint8_t *buf;
 134 } MatroskaTrackAudio;
 135
 136 typedef struct {
 137     uint64_t uid;
 138     uint64_t type;
 139 } MatroskaTrackPlane;
 140
 141 typedef struct {
 142     EbmlList combine_planes;
 143 } MatroskaTrackOperation;
 144
 145 typedef struct {
 146     uint64_t num;
 147     uint64_t uid;
 148     uint64_t type;
 149     char    *name;
 150     char    *codec_id;
 151     EbmlBin  codec_priv;
 152     char    *language;
 153     double time_scale;
 154     uint64_t default_duration;
 155     uint64_t flag_default;
 156     uint64_t flag_forced;
 157     MatroskaTrackVideo video;
 158     MatroskaTrackAudio audio;
 159     MatroskaTrackOperation operation;
 160     EbmlList encodings;
 161
 162     AVStream *stream;
 163     int64_t end_timecode;
 164     int ms_compat;
 165 } MatroskaTrack;
 166
 167 typedef struct {
 168     uint64_t uid;
 169     char *filename;
 170     char *mime;
 171     EbmlBin bin;
 172
 173     AVStream *stream;
 174 } MatroskaAttachement;
 175
 176 typedef struct {
 177     uint64_t start;
 178     uint64_t end;
 179     uint64_t uid;
 180     char    *title;
 181
 182     AVChapter *chapter;
 183 } MatroskaChapter;
 184
 185 typedef struct {
 186     uint64_t track;
 187     uint64_t pos;
 188 } MatroskaIndexPos;
 189
 190 typedef struct {
 191     uint64_t time;
 192     EbmlList pos;
 193 } MatroskaIndex;
 194
 195 typedef struct {
 196     char *name;
 197     char *string;
 198     char *lang;
 199     uint64_t def;
 200     EbmlList sub;
 201 } MatroskaTag;
 202
 203 typedef struct {
 204     char    *type;
 205     uint64_t typevalue;
 206     uint64_t trackuid;
 207     uint64_t chapteruid;
 208     uint64_t attachuid;
 209 } MatroskaTagTarget;
 210
 211 typedef struct {
 212     MatroskaTagTarget target;
 213     EbmlList tag;
 214 } MatroskaTags;
 215
 216 typedef struct {
 217     uint64_t id;
 218     uint64_t pos;
 219 } MatroskaSeekhead;
 220
 221 typedef struct {
 222     uint64_t start;
 223     uint64_t length;
 224 } MatroskaLevel;
 225
 226 typedef struct {
 227     uint64_t timecode;
 228     EbmlList blocks;
 229 } MatroskaCluster;
 230
 231 typedef struct {
 232     AVFormatContext *ctx;
 233
 234     /* EBML stuff */
 235     int num_levels;
 236     MatroskaLevel levels[EBML_MAX_DEPTH];
 237     int level_up;
 238     uint32_t current_id;
 239
 240     uint64_t time_scale;
 241     double   duration;
 242     char    *title;
 243     EbmlBin date_utc;
 244     EbmlList tracks;
 245     EbmlList attachments;
 246     EbmlList chapters;
 247     EbmlList index;
 248     EbmlList tags;
 249     EbmlList seekhead;
 250
 251     /* byte position of the segment inside the stream */
 252     int64_t segment_start;
 253
 254     /* the packet queue */
 255     AVPacket **packets;
 256     int num_packets;
 257     AVPacket *prev_pkt;
 258
 259     int done;
 260
 261     /* What to skip before effectively reading a packet. */
 262     int skip_to_keyframe;
 263     uint64_t skip_to_timecode;
 264
 265     /* File has a CUES element, but we defer parsing until it is needed. */
 266     int cues_parsing_deferred;
 267
 268     int current_cluster_num_blocks;
 269     int64_t current_cluster_pos;
 270     MatroskaCluster current_cluster;
 271
 272     /* File has SSA subtitles which prevent incremental cluster parsing. */
 273     int contains_ssa;
 274 } MatroskaDemuxContext;
 275
 276 typedef struct {
 277     uint64_t duration;
 278     int64_t  reference;
 279     uint64_t non_simple;
 280     EbmlBin  bin;
 281 } MatroskaBlock;
 282
 283 static EbmlSyntax ebml_header[] = {
 284     { EBML_ID_EBMLREADVERSION,        EBML_UINT, 0, offsetof(Ebml,version), {.u=EBML_VERSION} },
 285     { EBML_ID_EBMLMAXSIZELENGTH,      EBML_UINT, 0, offsetof(Ebml,max_size), {.u=8} },
 286     { EBML_ID_EBMLMAXIDLENGTH,        EBML_UINT, 0, offsetof(Ebml,id_length), {.u=4} },
 287     { EBML_ID_DOCTYPE,                EBML_STR,  0, offsetof(Ebml,doctype), {.s="(none)"} },
 288     { EBML_ID_DOCTYPEREADVERSION,     EBML_UINT, 0, offsetof(Ebml,doctype_version), {.u=1} },
 289     { EBML_ID_EBMLVERSION,            EBML_NONE },
 290     { EBML_ID_DOCTYPEVERSION,         EBML_NONE },
 291     { 0 }
 292 };
 293
 294 static EbmlSyntax ebml_syntax[] = {
 295     { EBML_ID_HEADER,                 EBML_NEST, 0, 0, {.n=ebml_header} },
 296     { 0 }
 297 };
 298
 299 static EbmlSyntax matroska_info[] = {
 300     { MATROSKA_ID_TIMECODESCALE,      EBML_UINT,  0, offsetof(MatroskaDemuxContext,time_scale), {.u=1000000} },
 301     { MATROSKA_ID_DURATION,           EBML_FLOAT, 0, offsetof(MatroskaDemuxContext,duration) },
 302     { MATROSKA_ID_TITLE,              EBML_UTF8,  0, offsetof(MatroskaDemuxContext,title) },
 303     { MATROSKA_ID_WRITINGAPP,         EBML_NONE },
 304     { MATROSKA_ID_MUXINGAPP,          EBML_NONE },
 305     { MATROSKA_ID_DATEUTC,            EBML_BIN,  0, offsetof(MatroskaDemuxContext,date_utc) },
 306     { MATROSKA_ID_SEGMENTUID,         EBML_NONE },
 307     { 0 }
 308 };
 309
 310 static EbmlSyntax matroska_track_video[] = {
 311     { MATROSKA_ID_VIDEOFRAMERATE,     EBML_FLOAT,0, offsetof(MatroskaTrackVideo,frame_rate) },
 312     { MATROSKA_ID_VIDEODISPLAYWIDTH,  EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_width) },
 313     { MATROSKA_ID_VIDEODISPLAYHEIGHT, EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_height) },
 314     { MATROSKA_ID_VIDEOPIXELWIDTH,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_width) },
 315     { MATROSKA_ID_VIDEOPIXELHEIGHT,   EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_height) },
 316     { MATROSKA_ID_VIDEOCOLORSPACE,    EBML_BIN,  0, offsetof(MatroskaTrackVideo,color_space) },
 317     { MATROSKA_ID_VIDEOSTEREOMODE,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,stereo_mode) },
 318     { MATROSKA_ID_VIDEOPIXELCROPB,    EBML_NONE },
 319     { MATROSKA_ID_VIDEOPIXELCROPT,    EBML_NONE },
 320     { MATROSKA_ID_VIDEOPIXELCROPL,    EBML_NONE },
 321     { MATROSKA_ID_VIDEOPIXELCROPR,    EBML_NONE },
 322     { MATROSKA_ID_VIDEODISPLAYUNIT,   EBML_NONE },
 323     { MATROSKA_ID_VIDEOFLAGINTERLACED,EBML_NONE },
 324     { MATROSKA_ID_VIDEOASPECTRATIO,   EBML_NONE },
 325     { 0 }
 326 };
 327
 328 static EbmlSyntax matroska_track_audio[] = {
 329     { MATROSKA_ID_AUDIOSAMPLINGFREQ,  EBML_FLOAT,0, offsetof(MatroskaTrackAudio,samplerate), {.f=8000.0} },
 330     { MATROSKA_ID_AUDIOOUTSAMPLINGFREQ,EBML_FLOAT,0,offsetof(MatroskaTrackAudio,out_samplerate) },
 331     { MATROSKA_ID_AUDIOBITDEPTH,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,bitdepth) },
 332     { MATROSKA_ID_AUDIOCHANNELS,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,channels), {.u=1} },
 333     { 0 }
 334 };
 335
 336 static EbmlSyntax matroska_track_encoding_compression[] = {
 337     { MATROSKA_ID_ENCODINGCOMPALGO,   EBML_UINT, 0, offsetof(MatroskaTrackCompression,algo), {.u=0} },
 338     { MATROSKA_ID_ENCODINGCOMPSETTINGS,EBML_BIN, 0, offsetof(MatroskaTrackCompression,settings) },
 339     { 0 }
 340 };
 341
 342 static EbmlSyntax matroska_track_encoding[] = {
 343     { MATROSKA_ID_ENCODINGSCOPE,      EBML_UINT, 0, offsetof(MatroskaTrackEncoding,scope), {.u=1} },
 344     { MATROSKA_ID_ENCODINGTYPE,       EBML_UINT, 0, offsetof(MatroskaTrackEncoding,type), {.u=0} },
 345     { MATROSKA_ID_ENCODINGCOMPRESSION,EBML_NEST, 0, offsetof(MatroskaTrackEncoding,compression), {.n=matroska_track_encoding_compression} },
 346     { MATROSKA_ID_ENCODINGORDER,      EBML_NONE },
 347     { 0 }
 348 };
 349
 350 static EbmlSyntax matroska_track_encodings[] = {
 351     { MATROSKA_ID_TRACKCONTENTENCODING, EBML_NEST, sizeof(MatroskaTrackEncoding), offsetof(MatroskaTrack,encodings), {.n=matroska_track_encoding} },
 352     { 0 }
 353 };
 354
 355 static EbmlSyntax matroska_track_plane[] = {
 356     { MATROSKA_ID_TRACKPLANEUID,  EBML_UINT, 0, offsetof(MatroskaTrackPlane,uid) },
 357     { MATROSKA_ID_TRACKPLANETYPE, EBML_UINT, 0, offsetof(MatroskaTrackPlane,type) },
 358     { 0 }
 359 };
 360
 361 static EbmlSyntax matroska_track_combine_planes[] = {
 362     { MATROSKA_ID_TRACKPLANE, EBML_NEST, sizeof(MatroskaTrackPlane), offsetof(MatroskaTrackOperation,combine_planes), {.n=matroska_track_plane} },
 363     { 0 }
 364 };
 365
 366 static EbmlSyntax matroska_track_operation[] = {
 367     { MATROSKA_ID_TRACKCOMBINEPLANES, EBML_NEST, 0, 0, {.n=matroska_track_combine_planes} },
 368     { 0 }
 369 };
 370
 371 static EbmlSyntax matroska_track[] = {
 372     { MATROSKA_ID_TRACKNUMBER,          EBML_UINT, 0, offsetof(MatroskaTrack,num) },
 373     { MATROSKA_ID_TRACKNAME,            EBML_UTF8, 0, offsetof(MatroskaTrack,name) },
 374     { MATROSKA_ID_TRACKUID,             EBML_UINT, 0, offsetof(MatroskaTrack,uid) },
 375     { MATROSKA_ID_TRACKTYPE,            EBML_UINT, 0, offsetof(MatroskaTrack,type) },
 376     { MATROSKA_ID_CODECID,              EBML_STR,  0, offsetof(MatroskaTrack,codec_id) },
 377     { MATROSKA_ID_CODECPRIVATE,         EBML_BIN,  0, offsetof(MatroskaTrack,codec_priv) },
 378     { MATROSKA_ID_TRACKLANGUAGE,        EBML_UTF8, 0, offsetof(MatroskaTrack,language), {.s="eng"} },
 379     { MATROSKA_ID_TRACKDEFAULTDURATION, EBML_UINT, 0, offsetof(MatroskaTrack,default_duration) },
 380     { MATROSKA_ID_TRACKTIMECODESCALE,   EBML_FLOAT,0, offsetof(MatroskaTrack,time_scale), {.f=1.0} },
 381     { MATROSKA_ID_TRACKFLAGDEFAULT,     EBML_UINT, 0, offsetof(MatroskaTrack,flag_default), {.u=1} },
 382     { MATROSKA_ID_TRACKFLAGFORCED,      EBML_UINT, 0, offsetof(MatroskaTrack,flag_forced), {.u=0} },
 383     { MATROSKA_ID_TRACKVIDEO,           EBML_NEST, 0, offsetof(MatroskaTrack,video), {.n=matroska_track_video} },
 384     { MATROSKA_ID_TRACKAUDIO,           EBML_NEST, 0, offsetof(MatroskaTrack,audio), {.n=matroska_track_audio} },
 385     { MATROSKA_ID_TRACKOPERATION,       EBML_NEST, 0, offsetof(MatroskaTrack,operation), {.n=matroska_track_operation} },
 386     { MATROSKA_ID_TRACKCONTENTENCODINGS,EBML_NEST, 0, 0, {.n=matroska_track_encodings} },
 387     { MATROSKA_ID_TRACKFLAGENABLED,     EBML_NONE },
 388     { MATROSKA_ID_TRACKFLAGLACING,      EBML_NONE },
 389     { MATROSKA_ID_CODECNAME,            EBML_NONE },
 390     { MATROSKA_ID_CODECDECODEALL,       EBML_NONE },
 391     { MATROSKA_ID_CODECINFOURL,         EBML_NONE },
 392     { MATROSKA_ID_CODECDOWNLOADURL,     EBML_NONE },
 393     { MATROSKA_ID_TRACKMINCACHE,        EBML_NONE },
 394     { MATROSKA_ID_TRACKMAXCACHE,        EBML_NONE },
 395     { MATROSKA_ID_TRACKMAXBLKADDID,     EBML_NONE },
 396     { 0 }
 397 };
 398
 399 static EbmlSyntax matroska_tracks[] = {
 400     { MATROSKA_ID_TRACKENTRY,         EBML_NEST, sizeof(MatroskaTrack), offsetof(MatroskaDemuxContext,tracks), {.n=matroska_track} },
 401     { 0 }
 402 };
 403
 404 static EbmlSyntax matroska_attachment[] = {
 405     { MATROSKA_ID_FILEUID,            EBML_UINT, 0, offsetof(MatroskaAttachement,uid) },
 406     { MATROSKA_ID_FILENAME,           EBML_UTF8, 0, offsetof(MatroskaAttachement,filename) },
 407     { MATROSKA_ID_FILEMIMETYPE,       EBML_STR,  0, offsetof(MatroskaAttachement,mime) },
 408     { MATROSKA_ID_FILEDATA,           EBML_BIN,  0, offsetof(MatroskaAttachement,bin) },
 409     { MATROSKA_ID_FILEDESC,           EBML_NONE },
 410     { 0 }
 411 };
 412
 413 static EbmlSyntax matroska_attachments[] = {
 414     { MATROSKA_ID_ATTACHEDFILE,       EBML_NEST, sizeof(MatroskaAttachement), offsetof(MatroskaDemuxContext,attachments), {.n=matroska_attachment} },
 415     { 0 }
 416 };
 417
 418 static EbmlSyntax matroska_chapter_display[] = {
 419     { MATROSKA_ID_CHAPSTRING,         EBML_UTF8, 0, offsetof(MatroskaChapter,title) },
 420     { MATROSKA_ID_CHAPLANG,           EBML_NONE },
 421     { 0 }
 422 };
 423
 424 static EbmlSyntax matroska_chapter_entry[] = {
 425     { MATROSKA_ID_CHAPTERTIMESTART,   EBML_UINT, 0, offsetof(MatroskaChapter,start), {.u=AV_NOPTS_VALUE} },
 426     { MATROSKA_ID_CHAPTERTIMEEND,     EBML_UINT, 0, offsetof(MatroskaChapter,end), {.u=AV_NOPTS_VALUE} },
 427     { MATROSKA_ID_CHAPTERUID,         EBML_UINT, 0, offsetof(MatroskaChapter,uid) },
 428     { MATROSKA_ID_CHAPTERDISPLAY,     EBML_NEST, 0, 0, {.n=matroska_chapter_display} },
 429     { MATROSKA_ID_CHAPTERFLAGHIDDEN,  EBML_NONE },
 430     { MATROSKA_ID_CHAPTERFLAGENABLED, EBML_NONE },
 431     { MATROSKA_ID_CHAPTERPHYSEQUIV,   EBML_NONE },
 432     { MATROSKA_ID_CHAPTERATOM,        EBML_NONE },
 433     { 0 }
 434 };
 435
 436 static EbmlSyntax matroska_chapter[] = {
 437     { MATROSKA_ID_CHAPTERATOM,        EBML_NEST, sizeof(MatroskaChapter), offsetof(MatroskaDemuxContext,chapters), {.n=matroska_chapter_entry} },
 438     { MATROSKA_ID_EDITIONUID,         EBML_NONE },
 439     { MATROSKA_ID_EDITIONFLAGHIDDEN,  EBML_NONE },
 440     { MATROSKA_ID_EDITIONFLAGDEFAULT, EBML_NONE },
 441     { MATROSKA_ID_EDITIONFLAGORDERED, EBML_NONE },
 442     { 0 }
 443 };
 444
 445 static EbmlSyntax matroska_chapters[] = {
 446     { MATROSKA_ID_EDITIONENTRY,       EBML_NEST, 0, 0, {.n=matroska_chapter} },
 447     { 0 }
 448 };
 449
 450 static EbmlSyntax matroska_index_pos[] = {
 451     { MATROSKA_ID_CUETRACK,           EBML_UINT, 0, offsetof(MatroskaIndexPos,track) },
 452     { MATROSKA_ID_CUECLUSTERPOSITION, EBML_UINT, 0, offsetof(MatroskaIndexPos,pos)   },
 453     { MATROSKA_ID_CUEBLOCKNUMBER,     EBML_NONE },
 454     { 0 }
 455 };
 456
 457 static EbmlSyntax matroska_index_entry[] = {
 458     { MATROSKA_ID_CUETIME,            EBML_UINT, 0, offsetof(MatroskaIndex,time) },
 459     { MATROSKA_ID_CUETRACKPOSITION,   EBML_NEST, sizeof(MatroskaIndexPos), offsetof(MatroskaIndex,pos), {.n=matroska_index_pos} },
 460     { 0 }
 461 };
 462
 463 static EbmlSyntax matroska_index[] = {
 464     { MATROSKA_ID_POINTENTRY,         EBML_NEST, sizeof(MatroskaIndex), offsetof(MatroskaDemuxContext,index), {.n=matroska_index_entry} },
 465     { 0 }
 466 };
 467
 468 static EbmlSyntax matroska_simpletag[] = {
 469     { MATROSKA_ID_TAGNAME,            EBML_UTF8, 0, offsetof(MatroskaTag,name) },
 470     { MATROSKA_ID_TAGSTRING,          EBML_UTF8, 0, offsetof(MatroskaTag,string) },
 471     { MATROSKA_ID_TAGLANG,            EBML_STR,  0, offsetof(MatroskaTag,lang), {.s="und"} },
 472     { MATROSKA_ID_TAGDEFAULT,         EBML_UINT, 0, offsetof(MatroskaTag,def) },
 473     { MATROSKA_ID_TAGDEFAULT_BUG,     EBML_UINT, 0, offsetof(MatroskaTag,def) },
 474     { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTag,sub), {.n=matroska_simpletag} },
 475     { 0 }
 476 };
 477
 478 static EbmlSyntax matroska_tagtargets[] = {
 479     { MATROSKA_ID_TAGTARGETS_TYPE,      EBML_STR,  0, offsetof(MatroskaTagTarget,type) },
 480     { MATROSKA_ID_TAGTARGETS_TYPEVALUE, EBML_UINT, 0, offsetof(MatroskaTagTarget,typevalue), {.u=50} },
 481     { MATROSKA_ID_TAGTARGETS_TRACKUID,  EBML_UINT, 0, offsetof(MatroskaTagTarget,trackuid) },
 482     { MATROSKA_ID_TAGTARGETS_CHAPTERUID,EBML_UINT, 0, offsetof(MatroskaTagTarget,chapteruid) },
 483     { MATROSKA_ID_TAGTARGETS_ATTACHUID, EBML_UINT, 0, offsetof(MatroskaTagTarget,attachuid) },
 484     { 0 }
 485 };
 486
 487 static EbmlSyntax matroska_tag[] = {
 488     { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTags,tag), {.n=matroska_simpletag} },
 489     { MATROSKA_ID_TAGTARGETS,         EBML_NEST, 0, offsetof(MatroskaTags,target), {.n=matroska_tagtargets} },
 490     { 0 }
 491 };
 492
 493 static EbmlSyntax matroska_tags[] = {
 494     { MATROSKA_ID_TAG,                EBML_NEST, sizeof(MatroskaTags), offsetof(MatroskaDemuxContext,tags), {.n=matroska_tag} },
 495     { 0 }
 496 };
 497
 498 static EbmlSyntax matroska_seekhead_entry[] = {
 499     { MATROSKA_ID_SEEKID,             EBML_UINT, 0, offsetof(MatroskaSeekhead,id) },
 500     { MATROSKA_ID_SEEKPOSITION,       EBML_UINT, 0, offsetof(MatroskaSeekhead,pos), {.u=-1} },
 501     { 0 }
 502 };
 503
 504 static EbmlSyntax matroska_seekhead[] = {
 505     { MATROSKA_ID_SEEKENTRY,          EBML_NEST, sizeof(MatroskaSeekhead), offsetof(MatroskaDemuxContext,seekhead), {.n=matroska_seekhead_entry} },
 506     { 0 }
 507 };
 508
 509 static EbmlSyntax matroska_segment[] = {
 510     { MATROSKA_ID_INFO,           EBML_NEST, 0, 0, {.n=matroska_info       } },
 511     { MATROSKA_ID_TRACKS,         EBML_NEST, 0, 0, {.n=matroska_tracks     } },
 512     { MATROSKA_ID_ATTACHMENTS,    EBML_NEST, 0, 0, {.n=matroska_attachments} },
 513     { MATROSKA_ID_CHAPTERS,       EBML_NEST, 0, 0, {.n=matroska_chapters   } },
 514     { MATROSKA_ID_CUES,           EBML_NEST, 0, 0, {.n=matroska_index      } },
 515     { MATROSKA_ID_TAGS,           EBML_NEST, 0, 0, {.n=matroska_tags       } },
 516     { MATROSKA_ID_SEEKHEAD,       EBML_NEST, 0, 0, {.n=matroska_seekhead   } },
 517     { MATROSKA_ID_CLUSTER,        EBML_STOP },
 518     { 0 }
 519 };
 520
 521 static EbmlSyntax matroska_segments[] = {
 522     { MATROSKA_ID_SEGMENT,        EBML_NEST, 0, 0, {.n=matroska_segment    } },
 523     { 0 }
 524 };
 525
 526 static EbmlSyntax matroska_blockgroup[] = {
 527     { MATROSKA_ID_BLOCK,          EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
 528     { MATROSKA_ID_SIMPLEBLOCK,    EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
 529     { MATROSKA_ID_BLOCKDURATION,  EBML_UINT, 0, offsetof(MatroskaBlock,duration) },
 530     { MATROSKA_ID_BLOCKREFERENCE, EBML_UINT, 0, offsetof(MatroskaBlock,reference) },
 531     { 1,                          EBML_UINT, 0, offsetof(MatroskaBlock,non_simple), {.u=1} },
 532     { 0 }
 533 };
 534
 535 static EbmlSyntax matroska_cluster[] = {
 536     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
 537     { MATROSKA_ID_BLOCKGROUP,     EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 538     { MATROSKA_ID_SIMPLEBLOCK,    EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 539     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
 540     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
 541     { 0 }
 542 };
 543
 544 static EbmlSyntax matroska_clusters[] = {
 545     { MATROSKA_ID_CLUSTER,        EBML_NEST, 0, 0, {.n=matroska_cluster} },
 546     { MATROSKA_ID_INFO,           EBML_NONE },
 547     { MATROSKA_ID_CUES,           EBML_NONE },
 548     { MATROSKA_ID_TAGS,           EBML_NONE },
 549     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
 550     { 0 }
 551 };
 552
 553 static EbmlSyntax matroska_cluster_incremental_parsing[] = {
 554     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
 555     { MATROSKA_ID_BLOCKGROUP,     EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 556     { MATROSKA_ID_SIMPLEBLOCK,    EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 557     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
 558     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
 559     { MATROSKA_ID_INFO,           EBML_NONE },
 560     { MATROSKA_ID_CUES,           EBML_NONE },
 561     { MATROSKA_ID_TAGS,           EBML_NONE },
 562     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
 563     { MATROSKA_ID_CLUSTER,        EBML_STOP },
 564     { 0 }
 565 };
 566
 567 static EbmlSyntax matroska_cluster_incremental[] = {
 568     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
 569     { MATROSKA_ID_BLOCKGROUP,     EBML_STOP },
 570     { MATROSKA_ID_SIMPLEBLOCK,    EBML_STOP },
 571     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
 572     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
 573     { 0 }
 574 };
 575
 576 static EbmlSyntax matroska_clusters_incremental[] = {
 577     { MATROSKA_ID_CLUSTER,        EBML_NEST, 0, 0, {.n=matroska_cluster_incremental} },
 578     { MATROSKA_ID_INFO,           EBML_NONE },
 579     { MATROSKA_ID_CUES,           EBML_NONE },
 580     { MATROSKA_ID_TAGS,           EBML_NONE },
 581     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
 582     { 0 }
 583 };
 584
 585 static const char *const matroska_doctypes[] = { "matroska", "webm" };
 586
 587 static int matroska_resync(MatroskaDemuxContext *matroska, int64_t last_pos)
 588 {
 589     AVIOContext *pb = matroska->ctx->pb;
 590     uint32_t id;
 591     matroska->current_id = 0;
 592     matroska->num_levels = 0;
 593
 594     // seek to next position to resync from
 595     if (avio_seek(pb, last_pos + 1, SEEK_SET) < 0 || avio_tell(pb) <= last_pos)
 596         goto eof;
 597
 598     id = avio_rb32(pb);
 599
 600     // try to find a toplevel element
 601     while (!url_feof(pb)) {
 602         if (id == MATROSKA_ID_INFO || id == MATROSKA_ID_TRACKS ||
 603             id == MATROSKA_ID_CUES || id == MATROSKA_ID_TAGS ||
 604             id == MATROSKA_ID_SEEKHEAD || id == MATROSKA_ID_ATTACHMENTS ||
 605             id == MATROSKA_ID_CLUSTER || id == MATROSKA_ID_CHAPTERS)
 606         {
 607             matroska->current_id = id;
 608             return 0;
 609         }
 610         id = (id << 8) | avio_r8(pb);
 611     }
 612 eof:
 613     matroska->done = 1;
 614     return AVERROR_EOF;
 615 }
 616
 617 /*
 618  * Return: Whether we reached the end of a level in the hierarchy or not.
 619  */
 620 static int ebml_level_end(MatroskaDemuxContext *matroska)
 621 {
 622     AVIOContext *pb = matroska->ctx->pb;
 623     int64_t pos = avio_tell(pb);
 624
 625     if (matroska->num_levels > 0) {
 626         MatroskaLevel *level = &matroska->levels[matroska->num_levels - 1];
 627         if (pos - level->start >= level->length || matroska->current_id) {
 628             matroska->num_levels--;
 629             return 1;
 630         }
 631     }
 632     return 0;
 633 }
 634
 635 /*
 636  * Read: an "EBML number", which is defined as a variable-length
 637  * array of bytes. The first byte indicates the length by giving a
 638  * number of 0-bits followed by a one. The position of the first
 639  * "one" bit inside the first byte indicates the length of this
 640  * number.
 641  * Returns: number of bytes read, < 0 on error
 642  */
 643 static int ebml_read_num(MatroskaDemuxContext *matroska, AVIOContext *pb,
 644                          int max_size, uint64_t *number)
 645 {
 646     int read = 1, n = 1;
 647     uint64_t total = 0;
 648
 649     /* The first byte tells us the length in bytes - avio_r8() can normally
 650      * return 0, but since that's not a valid first ebmlID byte, we can
 651      * use it safely here to catch EOS. */
 652     if (!(total = avio_r8(pb))) {
 653         /* we might encounter EOS here */
 654         if (!url_feof(pb)) {
 655             int64_t pos = avio_tell(pb);
 656             av_log(matroska->ctx, AV_LOG_ERROR,
 657                    "Read error at pos. %"PRIu64" (0x%"PRIx64")\n",
 658                    pos, pos);
 659             return pb->error ? pb->error : AVERROR(EIO);
 660         }
 661         return AVERROR_EOF;
 662     }
 663
 664     /* get the length of the EBML number */
 665     read = 8 - ff_log2_tab[total];
 666     if (read > max_size) {
 667         int64_t pos = avio_tell(pb) - 1;
 668         av_log(matroska->ctx, AV_LOG_ERROR,
 669                "Invalid EBML number size tag 0x%02x at pos %"PRIu64" (0x%"PRIx64")\n",
 670                (uint8_t) total, pos, pos);
 671         return AVERROR_INVALIDDATA;
 672     }
 673
 674     /* read out length */
 675     total ^= 1 << ff_log2_tab[total];
 676     while (n++ < read)
 677         total = (total << 8) | avio_r8(pb);
 678
 679     *number = total;
 680
 681     return read;
 682 }
 683
 684 /**
 685  * Read a EBML length value.
 686  * This needs special handling for the "unknown length" case which has multiple
 687  * encodings.
 688  */
 689 static int ebml_read_length(MatroskaDemuxContext *matroska, AVIOContext *pb,
 690                             uint64_t *number)
 691 {
 692     int res = ebml_read_num(matroska, pb, 8, number);
 693     if (res > 0 && *number + 1 == 1ULL << (7 * res))
 694         *number = 0xffffffffffffffULL;
 695     return res;
 696 }
 697
 698 /*
 699  * Read the next element as an unsigned int.
 700  * 0 is success, < 0 is failure.
 701  */
 702 static int ebml_read_uint(AVIOContext *pb, int size, uint64_t *num)
 703 {
 704     int n = 0;
 705
 706     if (size > 8)
 707         return AVERROR_INVALIDDATA;
 708
 709     /* big-endian ordering; build up number */
 710     *num = 0;
 711     while (n++ < size)
 712         *num = (*num << 8) | avio_r8(pb);
 713
 714     return 0;
 715 }
 716
 717 /*
 718  * Read the next element as a float.
 719  * 0 is success, < 0 is failure.
 720  */
 721 static int ebml_read_float(AVIOContext *pb, int size, double *num)
 722 {
 723     if (size == 0) {
 724         *num = 0;
 725     } else if (size == 4) {
 726         *num = av_int2float(avio_rb32(pb));
 727     } else if (size == 8){
 728         *num = av_int2double(avio_rb64(pb));
 729     } else
 730         return AVERROR_INVALIDDATA;
 731
 732     return 0;
 733 }
 734
 735 /*
 736  * Read the next element as an ASCII string.
 737  * 0 is success, < 0 is failure.
 738  */
 739 static int ebml_read_ascii(AVIOContext *pb, int size, char **str)
 740 {
 741     char *res;
 742
 743     /* EBML strings are usually not 0-terminated, so we allocate one
 744      * byte more, read the string and NULL-terminate it ourselves. */
 745     if (!(res = av_malloc(size + 1)))
 746         return AVERROR(ENOMEM);
 747     if (avio_read(pb, (uint8_t *) res, size) != size) {
 748         av_free(res);
 749         return AVERROR(EIO);
 750     }
 751     (res)[size] = '\0';
 752     av_free(*str);
 753     *str = res;
 754
 755     return 0;
 756 }
 757
 758 /*
 759  * Read the next element as binary data.
 760  * 0 is success, < 0 is failure.
 761  */
 762 static int ebml_read_binary(AVIOContext *pb, int length, EbmlBin *bin)
 763 {
 764     av_free(bin->data);
 765     if (!(bin->data = av_malloc(length)))
 766         return AVERROR(ENOMEM);
 767
 768     bin->size = length;
 769     bin->pos  = avio_tell(pb);
 770     if (avio_read(pb, bin->data, length) != length) {
 771         av_freep(&bin->data);
 772         return AVERROR(EIO);
 773     }
 774
 775     return 0;
 776 }
 777
 778 /*
 779  * Read the next element, but only the header. The contents
 780  * are supposed to be sub-elements which can be read separately.
 781  * 0 is success, < 0 is failure.
 782  */
 783 static int ebml_read_master(MatroskaDemuxContext *matroska, uint64_t length)
 784 {
 785     AVIOContext *pb = matroska->ctx->pb;
 786     MatroskaLevel *level;
 787
 788     if (matroska->num_levels >= EBML_MAX_DEPTH) {
 789         av_log(matroska->ctx, AV_LOG_ERROR,
 790                "File moves beyond max. allowed depth (%d)\n", EBML_MAX_DEPTH);
 791         return AVERROR(ENOSYS);
 792     }
 793
 794     level = &matroska->levels[matroska->num_levels++];
 795     level->start = avio_tell(pb);
 796     level->length = length;
 797
 798     return 0;
 799 }
 800
 801 /*
 802  * Read signed/unsigned "EBML" numbers.
 803  * Return: number of bytes processed, < 0 on error
 804  */
 805 static int matroska_ebmlnum_uint(MatroskaDemuxContext *matroska,
 806                                  uint8_t *data, uint32_t size, uint64_t *num)
 807 {
 808     AVIOContext pb;
 809     ffio_init_context(&pb, data, size, 0, NULL, NULL, NULL, NULL);
 810     return ebml_read_num(matroska, &pb, FFMIN(size, 8), num);
 811 }
 812
 813 /*
 814  * Same as above, but signed.
 815  */
 816 static int matroska_ebmlnum_sint(MatroskaDemuxContext *matroska,
 817                                  uint8_t *data, uint32_t size, int64_t *num)
 818 {
 819     uint64_t unum;
 820     int res;
 821
 822     /* read as unsigned number first */
 823     if ((res = matroska_ebmlnum_uint(matroska, data, size, &unum)) < 0)
 824         return res;
 825
 826     /* make signed (weird way) */
 827     *num = unum - ((1LL << (7*res - 1)) - 1);
 828
 829     return res;
 830 }
 831
 832 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
 833                            EbmlSyntax *syntax, void *data);
 834
 835 static int ebml_parse_id(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 836                          uint32_t id, void *data)
 837 {
 838     int i;
 839     for (i=0; syntax[i].id; i++)
 840         if (id == syntax[i].id)
 841             break;
 842     if (!syntax[i].id && id == MATROSKA_ID_CLUSTER &&
 843         matroska->num_levels > 0 &&
 844         matroska->levels[matroska->num_levels-1].length == 0xffffffffffffff)
 845         return 0;  // we reached the end of an unknown size cluster
 846     if (!syntax[i].id && id != EBML_ID_VOID && id != EBML_ID_CRC32) {
 847         av_log(matroska->ctx, AV_LOG_INFO, "Unknown entry 0x%X\n", id);
 848         if (matroska->ctx->error_recognition & AV_EF_EXPLODE)
 849             return AVERROR_INVALIDDATA;
 850     }
 851     return ebml_parse_elem(matroska, &syntax[i], data);
 852 }
 853
 854 static int ebml_parse(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 855                       void *data)
 856 {
 857     if (!matroska->current_id) {
 858         uint64_t id;
 859         int res = ebml_read_num(matroska, matroska->ctx->pb, 4, &id);
 860         if (res < 0)
 861             return res;
 862         matroska->current_id = id | 1 << 7*res;
 863     }
 864     return ebml_parse_id(matroska, syntax, matroska->current_id, data);
 865 }
 866
 867 static int ebml_parse_nest(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 868                            void *data)
 869 {
 870     int i, res = 0;
 871
 872     for (i=0; syntax[i].id; i++)
 873         switch (syntax[i].type) {
 874         case EBML_UINT:
 875             *(uint64_t *)((char *)data+syntax[i].data_offset) = syntax[i].def.u;
 876             break;
 877         case EBML_FLOAT:
 878             *(double   *)((char *)data+syntax[i].data_offset) = syntax[i].def.f;
 879             break;
 880         case EBML_STR:
 881         case EBML_UTF8:
 882             *(char    **)((char *)data+syntax[i].data_offset) = av_strdup(syntax[i].def.s);
 883             break;
 884         }
 885
 886     while (!res && !ebml_level_end(matroska))
 887         res = ebml_parse(matroska, syntax, data);
 888
 889     return res;
 890 }
 891
 892 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
 893                            EbmlSyntax *syntax, void *data)
 894 {
 895     static const uint64_t max_lengths[EBML_TYPE_COUNT] = {
 896         [EBML_UINT]  = 8,
 897         [EBML_FLOAT] = 8,
 898         // max. 16 MB for strings
 899         [EBML_STR]   = 0x1000000,
 900         [EBML_UTF8]  = 0x1000000,
 901         // max. 256 MB for binary data
 902         [EBML_BIN]   = 0x10000000,
 903         // no limits for anything else
 904     };
 905     AVIOContext *pb = matroska->ctx->pb;
 906     uint32_t id = syntax->id;
 907     uint64_t length;
 908     int res;
 909     void *newelem;
 910
 911     data = (char *)data + syntax->data_offset;
 912     if (syntax->list_elem_size) {
 913         EbmlList *list = data;
 914         newelem = av_realloc(list->elem, (list->nb_elem+1)*syntax->list_elem_size);
 915         if (!newelem)
 916             return AVERROR(ENOMEM);
 917         list->elem = newelem;
 918         data = (char*)list->elem + list->nb_elem*syntax->list_elem_size;
 919         memset(data, 0, syntax->list_elem_size);
 920         list->nb_elem++;
 921     }
 922
 923     if (syntax->type != EBML_PASS && syntax->type != EBML_STOP) {
 924         matroska->current_id = 0;
 925         if ((res = ebml_read_length(matroska, pb, &length)) < 0)
 926             return res;
 927         if (max_lengths[syntax->type] && length > max_lengths[syntax->type]) {
 928             av_log(matroska->ctx, AV_LOG_ERROR,
 929                    "Invalid length 0x%"PRIx64" > 0x%"PRIx64" for syntax element %i\n",
 930                    length, max_lengths[syntax->type], syntax->type);
 931             return AVERROR_INVALIDDATA;
 932         }
 933     }
 934
 935     switch (syntax->type) {
 936     case EBML_UINT:  res = ebml_read_uint  (pb, length, data);  break;
 937     case EBML_FLOAT: res = ebml_read_float (pb, length, data);  break;
 938     case EBML_STR:
 939     case EBML_UTF8:  res = ebml_read_ascii (pb, length, data);  break;
 940     case EBML_BIN:   res = ebml_read_binary(pb, length, data);  break;
 941     case EBML_NEST:  if ((res=ebml_read_master(matroska, length)) < 0)
 942                          return res;
 943                      if (id == MATROSKA_ID_SEGMENT)
 944                          matroska->segment_start = avio_tell(matroska->ctx->pb);
 945                      return ebml_parse_nest(matroska, syntax->def.n, data);
 946     case EBML_PASS:  return ebml_parse_id(matroska, syntax->def.n, id, data);
 947     case EBML_STOP:  return 1;
 948     default:         return avio_skip(pb,length)<0 ? AVERROR(EIO) : 0;
 949     }
 950     if (res == AVERROR_INVALIDDATA)
 951         av_log(matroska->ctx, AV_LOG_ERROR, "Invalid element\n");
 952     else if (res == AVERROR(EIO))
 953         av_log(matroska->ctx, AV_LOG_ERROR, "Read error\n");
 954     return res;
 955 }
 956
 957 static void ebml_free(EbmlSyntax *syntax, void *data)
 958 {
 959     int i, j;
 960     for (i=0; syntax[i].id; i++) {
 961         void *data_off = (char *)data + syntax[i].data_offset;
 962         switch (syntax[i].type) {
 963         case EBML_STR:
 964         case EBML_UTF8:  av_freep(data_off);                      break;
 965         case EBML_BIN:   av_freep(&((EbmlBin *)data_off)->data);  break;
 966         case EBML_NEST:
 967             if (syntax[i].list_elem_size) {
 968                 EbmlList *list = data_off;
 969                 char *ptr = list->elem;
 970                 for (j=0; j<list->nb_elem; j++, ptr+=syntax[i].list_elem_size)
 971                     ebml_free(syntax[i].def.n, ptr);
 972                 av_free(list->elem);
 973             } else
 974                 ebml_free(syntax[i].def.n, data_off);
 975         default:  break;
 976         }
 977     }
 978 }
 979
 980
 981 /*
 982  * Autodetecting...
 983  */
 984 static int matroska_probe(AVProbeData *p)
 985 {
 986     uint64_t total = 0;
 987     int len_mask = 0x80, size = 1, n = 1, i;
 988
 989     /* EBML header? */
 990     if (AV_RB32(p->buf) != EBML_ID_HEADER)
 991         return 0;
 992
 993     /* length of header */
 994     total = p->buf[4];
 995     while (size <= 8 && !(total & len_mask)) {
 996         size++;
 997         len_mask >>= 1;
 998     }
 999     if (size > 8)
1000       return 0;
1001     total &= (len_mask - 1);
1002     while (n < size)
1003         total = (total << 8) | p->buf[4 + n++];
1004
1005     /* Does the probe data contain the whole header? */
1006     if (p->buf_size < 4 + size + total)
1007       return 0;
1008
1009     /* The header should contain a known document type. For now,
1010      * we don't parse the whole header but simply check for the
1011      * availability of that array of characters inside the header.
1012      * Not fully fool-proof, but good enough. */
1013     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++) {
1014         int probelen = strlen(matroska_doctypes[i]);
1015         if (total < probelen)
1016             continue;
1017         for (n = 4+size; n <= 4+size+total-probelen; n++)
1018             if (!memcmp(p->buf+n, matroska_doctypes[i], probelen))
1019                 return AVPROBE_SCORE_MAX;
1020     }
1021
1022     // probably valid EBML header but no recognized doctype
1023     return AVPROBE_SCORE_MAX/2;
1024 }
1025
1026 static MatroskaTrack *matroska_find_track_by_num(MatroskaDemuxContext *matroska,
1027                                                  int num)
1028 {
1029     MatroskaTrack *tracks = matroska->tracks.elem;
1030     int i;
1031
1032     for (i=0; i < matroska->tracks.nb_elem; i++)
1033         if (tracks[i].num == num)
1034             return &tracks[i];
1035
1036     av_log(matroska->ctx, AV_LOG_ERROR, "Invalid track number %d\n", num);
1037     return NULL;
1038 }
1039
1040 static int matroska_decode_buffer(uint8_t** buf, int* buf_size,
1041                                   MatroskaTrack *track)
1042 {
1043     MatroskaTrackEncoding *encodings = track->encodings.elem;
1044     uint8_t* data = *buf;
1045     int isize = *buf_size;
1046     uint8_t* pkt_data = NULL;
1047     uint8_t av_unused *newpktdata;
1048     int pkt_size = isize;
1049     int result = 0;
1050     int olen;
1051
1052     if (pkt_size >= 10000000U)
1053         return -1;
1054
1055     switch (encodings[0].compression.algo) {
1056     case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP:
1057         if (encodings[0].compression.settings.size && !encodings[0].compression.settings.data) {
1058             av_log(0, AV_LOG_ERROR, "Compression size but no data in headerstrip\n");
1059             return -1;
1060         }
1061         return encodings[0].compression.settings.size;
1062     case MATROSKA_TRACK_ENCODING_COMP_LZO:
1063         do {
1064             olen = pkt_size *= 3;
1065             pkt_data = av_realloc(pkt_data, pkt_size+AV_LZO_OUTPUT_PADDING);
1066             result = av_lzo1x_decode(pkt_data, &olen, data, &isize);
1067         } while (result==AV_LZO_OUTPUT_FULL && pkt_size<10000000);
1068         if (result)
1069             goto failed;
1070         pkt_size -= olen;
1071         break;
1072 #if CONFIG_ZLIB
1073     case MATROSKA_TRACK_ENCODING_COMP_ZLIB: {
1074         z_stream zstream = {0};
1075         if (inflateInit(&zstream) != Z_OK)
1076             return -1;
1077         zstream.next_in = data;
1078         zstream.avail_in = isize;
1079         do {
1080             pkt_size *= 3;
1081             newpktdata = av_realloc(pkt_data, pkt_size);
1082             if (!newpktdata) {
1083                 inflateEnd(&zstream);
1084                 goto failed;
1085             }
1086             pkt_data = newpktdata;
1087             zstream.avail_out = pkt_size - zstream.total_out;
1088             zstream.next_out = pkt_data + zstream.total_out;
1089             if (pkt_data) {
1090                 result = inflate(&zstream, Z_NO_FLUSH);
1091             } else
1092                 result = Z_MEM_ERROR;
1093         } while (result==Z_OK && pkt_size<10000000);
1094         pkt_size = zstream.total_out;
1095         inflateEnd(&zstream);
1096         if (result != Z_STREAM_END)
1097             goto failed;
1098         break;
1099     }
1100 #endif
1101 #if CONFIG_BZLIB
1102     case MATROSKA_TRACK_ENCODING_COMP_BZLIB: {
1103         bz_stream bzstream = {0};
1104         if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
1105             return -1;
1106         bzstream.next_in = data;
1107         bzstream.avail_in = isize;
1108         do {
1109             pkt_size *= 3;
1110             newpktdata = av_realloc(pkt_data, pkt_size);
1111             if (!newpktdata) {
1112                 BZ2_bzDecompressEnd(&bzstream);
1113                 goto failed;
1114             }
1115             pkt_data = newpktdata;
1116             bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
1117             bzstream.next_out = pkt_data + bzstream.total_out_lo32;
1118             if (pkt_data) {
1119                 result = BZ2_bzDecompress(&bzstream);
1120             } else
1121                 result = BZ_MEM_ERROR;
1122         } while (result==BZ_OK && pkt_size<10000000);
1123         pkt_size = bzstream.total_out_lo32;
1124         BZ2_bzDecompressEnd(&bzstream);
1125         if (result != BZ_STREAM_END)
1126             goto failed;
1127         break;
1128     }
1129 #endif
1130     default:
1131         return -1;
1132     }
1133
1134     *buf = pkt_data;
1135     *buf_size = pkt_size;
1136     return 0;
1137  failed:
1138     av_free(pkt_data);
1139     return -1;
1140 }
1141
1142 static void matroska_fix_ass_packet(MatroskaDemuxContext *matroska,
1143                                     AVPacket *pkt, uint64_t display_duration)
1144 {
1145     char *line, *layer, *ptr = pkt->data, *end = ptr+pkt->size;
1146     for (; *ptr!=',' && ptr<end-1; ptr++);
1147     if (*ptr == ',')
1148         ptr++;
1149     layer = ptr;
1150     for (; *ptr!=',' && ptr<end-1; ptr++);
1151     if (*ptr == ',') {
1152         int64_t end_pts = pkt->pts + display_duration;
1153         int sc = matroska->time_scale * pkt->pts / 10000000;
1154         int ec = matroska->time_scale * end_pts  / 10000000;
1155         int sh, sm, ss, eh, em, es, len;
1156         sh = sc/360000;  sc -= 360000*sh;
1157         sm = sc/  6000;  sc -=   6000*sm;
1158         ss = sc/   100;  sc -=    100*ss;
1159         eh = ec/360000;  ec -= 360000*eh;
1160         em = ec/  6000;  ec -=   6000*em;
1161         es = ec/   100;  ec -=    100*es;
1162         *ptr++ = '\0';
1163         len = 50 + end-ptr + FF_INPUT_BUFFER_PADDING_SIZE;
1164         if (!(line = av_malloc(len)))
1165             return;
1166         snprintf(line,len,"Dialogue: %s,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s\r\n",
1167                  layer, sh, sm, ss, sc, eh, em, es, ec, ptr);
1168         av_free(pkt->data);
1169         pkt->data = line;
1170         pkt->size = strlen(line);
1171     }
1172 }
1173
1174 static int matroska_merge_packets(AVPacket *out, AVPacket *in)
1175 {
1176     int ret = av_grow_packet(out, in->size);
1177     if (ret < 0)
1178         return ret;
1179     memcpy(out->data + out->size - in->size, in->data, in->size);
1180     av_destruct_packet(in);
1181     av_free(in);
1182     return 0;
1183 }
1184
1185 static void matroska_convert_tag(AVFormatContext *s, EbmlList *list,
1186                                  AVDictionary **metadata, char *prefix)
1187 {
1188     MatroskaTag *tags = list->elem;
1189     char key[1024];
1190     int i;
1191
1192     for (i=0; i < list->nb_elem; i++) {
1193         const char *lang= (tags[i].lang && strcmp(tags[i].lang, "und")) ? tags[i].lang : NULL;
1194
1195         if (!tags[i].name) {
1196             av_log(s, AV_LOG_WARNING, "Skipping invalid tag with no TagName.\n");
1197             continue;
1198         }
1199         if (prefix)  snprintf(key, sizeof(key), "%s/%s", prefix, tags[i].name);
1200         else         av_strlcpy(key, tags[i].name, sizeof(key));
1201         if (tags[i].def || !lang) {
1202         av_dict_set(metadata, key, tags[i].string, 0);
1203         if (tags[i].sub.nb_elem)
1204             matroska_convert_tag(s, &tags[i].sub, metadata, key);
1205         }
1206         if (lang) {
1207             av_strlcat(key, "-", sizeof(key));
1208             av_strlcat(key, lang, sizeof(key));
1209             av_dict_set(metadata, key, tags[i].string, 0);
1210             if (tags[i].sub.nb_elem)
1211                 matroska_convert_tag(s, &tags[i].sub, metadata, key);
1212         }
1213     }
1214     ff_metadata_conv(metadata, NULL, ff_mkv_metadata_conv);
1215 }
1216
1217 static void matroska_convert_tags(AVFormatContext *s)
1218 {
1219     MatroskaDemuxContext *matroska = s->priv_data;
1220     MatroskaTags *tags = matroska->tags.elem;
1221     int i, j;
1222
1223     for (i=0; i < matroska->tags.nb_elem; i++) {
1224         if (tags[i].target.attachuid) {
1225             MatroskaAttachement *attachment = matroska->attachments.elem;
1226             for (j=0; j<matroska->attachments.nb_elem; j++)
1227                 if (attachment[j].uid == tags[i].target.attachuid
1228                     && attachment[j].stream)
1229                     matroska_convert_tag(s, &tags[i].tag,
1230                                          &attachment[j].stream->metadata, NULL);
1231         } else if (tags[i].target.chapteruid) {
1232             MatroskaChapter *chapter = matroska->chapters.elem;
1233             for (j=0; j<matroska->chapters.nb_elem; j++)
1234                 if (chapter[j].uid == tags[i].target.chapteruid
1235                     && chapter[j].chapter)
1236                     matroska_convert_tag(s, &tags[i].tag,
1237                                          &chapter[j].chapter->metadata, NULL);
1238         } else if (tags[i].target.trackuid) {
1239             MatroskaTrack *track = matroska->tracks.elem;
1240             for (j=0; j<matroska->tracks.nb_elem; j++)
1241                 if (track[j].uid == tags[i].target.trackuid && track[j].stream)
1242                     matroska_convert_tag(s, &tags[i].tag,
1243                                          &track[j].stream->metadata, NULL);
1244         } else {
1245             matroska_convert_tag(s, &tags[i].tag, &s->metadata,
1246                                  tags[i].target.type);
1247         }
1248     }
1249 }
1250
1251 static int matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska, int idx)
1252 {
1253     EbmlList *seekhead_list = &matroska->seekhead;
1254     MatroskaSeekhead *seekhead = seekhead_list->elem;
1255     uint32_t level_up = matroska->level_up;
1256     int64_t before_pos = avio_tell(matroska->ctx->pb);
1257     uint32_t saved_id = matroska->current_id;
1258     MatroskaLevel level;
1259     int64_t offset;
1260     int ret = 0;
1261
1262     if (idx >= seekhead_list->nb_elem
1263             || seekhead[idx].id == MATROSKA_ID_SEEKHEAD
1264             || seekhead[idx].id == MATROSKA_ID_CLUSTER)
1265         return 0;
1266
1267     /* seek */
1268     offset = seekhead[idx].pos + matroska->segment_start;
1269     if (avio_seek(matroska->ctx->pb, offset, SEEK_SET) == offset) {
1270         /* We don't want to lose our seekhead level, so we add
1271          * a dummy. This is a crude hack. */
1272         if (matroska->num_levels == EBML_MAX_DEPTH) {
1273             av_log(matroska->ctx, AV_LOG_INFO,
1274                    "Max EBML element depth (%d) reached, "
1275                    "cannot parse further.\n", EBML_MAX_DEPTH);
1276             ret = AVERROR_INVALIDDATA;
1277         } else {
1278             level.start = 0;
1279             level.length = (uint64_t)-1;
1280             matroska->levels[matroska->num_levels] = level;
1281             matroska->num_levels++;
1282             matroska->current_id = 0;
1283
1284             ret = ebml_parse(matroska, matroska_segment, matroska);
1285
1286             /* remove dummy level */
1287             while (matroska->num_levels) {
1288                 uint64_t length = matroska->levels[--matroska->num_levels].length;
1289                 if (length == (uint64_t)-1)
1290                     break;
1291             }
1292         }
1293     }
1294     /* seek back */
1295     avio_seek(matroska->ctx->pb, before_pos, SEEK_SET);
1296     matroska->level_up = level_up;
1297     matroska->current_id = saved_id;
1298
1299     return ret;
1300 }
1301
1302 static void matroska_execute_seekhead(MatroskaDemuxContext *matroska)
1303 {
1304     EbmlList *seekhead_list = &matroska->seekhead;
1305     int64_t before_pos = avio_tell(matroska->ctx->pb);
1306     int i;
1307
1308     // we should not do any seeking in the streaming case
1309     if (!matroska->ctx->pb->seekable ||
1310         (matroska->ctx->flags & AVFMT_FLAG_IGNIDX))
1311         return;
1312
1313     for (i = 0; i < seekhead_list->nb_elem; i++) {
1314         MatroskaSeekhead *seekhead = seekhead_list->elem;
1315         if (seekhead[i].pos <= before_pos)
1316             continue;
1317
1318         // defer cues parsing until we actually need cue data.
1319         if (seekhead[i].id == MATROSKA_ID_CUES) {
1320             matroska->cues_parsing_deferred = 1;
1321             continue;
1322         }
1323
1324         if (matroska_parse_seekhead_entry(matroska, i) < 0) {
1325             // mark index as broken
1326             matroska->cues_parsing_deferred = -1;
1327             break;
1328         }
1329     }
1330 }
1331
1332 static void matroska_add_index_entries(MatroskaDemuxContext *matroska) {
1333     EbmlList *index_list;
1334     MatroskaIndex *index;
1335     int index_scale = 1;
1336     int i, j;
1337
1338     index_list = &matroska->index;
1339     index = index_list->elem;
1340     if (index_list->nb_elem
1341         && index[0].time > 1E14/matroska->time_scale) {
1342         av_log(matroska->ctx, AV_LOG_WARNING, "Working around broken index.\n");
1343         index_scale = matroska->time_scale;
1344     }
1345     for (i = 0; i < index_list->nb_elem; i++) {
1346         EbmlList *pos_list = &index[i].pos;
1347         MatroskaIndexPos *pos = pos_list->elem;
1348         for (j = 0; j < pos_list->nb_elem; j++) {
1349             MatroskaTrack *track = matroska_find_track_by_num(matroska, pos[j].track);
1350             if (track && track->stream)
1351                 av_add_index_entry(track->stream,
1352                                    pos[j].pos + matroska->segment_start,
1353                                    index[i].time/index_scale, 0, 0,
1354                                    AVINDEX_KEYFRAME);
1355         }
1356     }
1357 }
1358
1359 static void matroska_parse_cues(MatroskaDemuxContext *matroska) {
1360     EbmlList *seekhead_list = &matroska->seekhead;
1361     MatroskaSeekhead *seekhead = seekhead_list->elem;
1362     int i;
1363
1364     for (i = 0; i < seekhead_list->nb_elem; i++)
1365         if (seekhead[i].id == MATROSKA_ID_CUES)
1366             break;
1367     assert(i <= seekhead_list->nb_elem);
1368
1369     if (matroska_parse_seekhead_entry(matroska, i) < 0)
1370        matroska->cues_parsing_deferred = -1;
1371     matroska_add_index_entries(matroska);
1372 }
1373
1374 static int matroska_aac_profile(char *codec_id)
1375 {
1376     static const char * const aac_profiles[] = { "MAIN", "LC", "SSR" };
1377     int profile;
1378
1379     for (profile=0; profile<FF_ARRAY_ELEMS(aac_profiles); profile++)
1380         if (strstr(codec_id, aac_profiles[profile]))
1381             break;
1382     return profile + 1;
1383 }
1384
1385 static int matroska_aac_sri(int samplerate)
1386 {
1387     int sri;
1388
1389     for (sri=0; sri<FF_ARRAY_ELEMS(avpriv_mpeg4audio_sample_rates); sri++)
1390         if (avpriv_mpeg4audio_sample_rates[sri] == samplerate)
1391             break;
1392     return sri;
1393 }
1394
1395 static void matroska_metadata_creation_time(AVDictionary **metadata, int64_t date_utc)
1396 {
1397     char buffer[32];
1398     /* Convert to seconds and adjust by number of seconds between 2001-01-01 and Epoch */
1399     time_t creation_time = date_utc / 1000000000 + 978307200;
1400     struct tm *ptm = gmtime(&creation_time);
1401     if (!ptm) return;
1402     strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", ptm);
1403     av_dict_set(metadata, "creation_time", buffer, 0);
1404 }
1405
1406 static int matroska_read_header(AVFormatContext *s)
1407 {
1408     MatroskaDemuxContext *matroska = s->priv_data;
1409     EbmlList *attachements_list = &matroska->attachments;
1410     MatroskaAttachement *attachements;
1411     EbmlList *chapters_list = &matroska->chapters;
1412     MatroskaChapter *chapters;
1413     MatroskaTrack *tracks;
1414     uint64_t max_start = 0;
1415     int64_t pos;
1416     Ebml ebml = { 0 };
1417     AVStream *st;
1418     int i, j, k, res;
1419
1420     matroska->ctx = s;
1421
1422     /* First read the EBML header. */
1423     if (ebml_parse(matroska, ebml_syntax, &ebml)
1424         || ebml.version > EBML_VERSION       || ebml.max_size > sizeof(uint64_t)
1425         || ebml.id_length > sizeof(uint32_t) || ebml.doctype_version > 3 || !ebml.doctype) {
1426         av_log(matroska->ctx, AV_LOG_ERROR,
1427                "EBML header using unsupported features\n"
1428                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
1429                ebml.version, ebml.doctype, ebml.doctype_version);
1430         ebml_free(ebml_syntax, &ebml);
1431         return AVERROR_PATCHWELCOME;
1432     } else if (ebml.doctype_version == 3) {
1433         av_log(matroska->ctx, AV_LOG_WARNING,
1434                "EBML header using unsupported features\n"
1435                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
1436                ebml.version, ebml.doctype, ebml.doctype_version);
1437     }
1438     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++)
1439         if (!strcmp(ebml.doctype, matroska_doctypes[i]))
1440             break;
1441     if (i >= FF_ARRAY_ELEMS(matroska_doctypes)) {
1442         av_log(s, AV_LOG_WARNING, "Unknown EBML doctype '%s'\n", ebml.doctype);
1443     }
1444     ebml_free(ebml_syntax, &ebml);
1445
1446     /* The next thing is a segment. */
1447     pos = avio_tell(matroska->ctx->pb);
1448     res = ebml_parse(matroska, matroska_segments, matroska);
1449     // try resyncing until we find a EBML_STOP type element.
1450     while (res != 1) {
1451         res = matroska_resync(matroska, pos);
1452         if (res < 0)
1453             return res;
1454         pos = avio_tell(matroska->ctx->pb);
1455         res = ebml_parse(matroska, matroska_segment, matroska);
1456     }
1457     matroska_execute_seekhead(matroska);
1458
1459     if (!matroska->time_scale)
1460         matroska->time_scale = 1000000;
1461     if (matroska->duration)
1462         matroska->ctx->duration = matroska->duration * matroska->time_scale
1463                                   * 1000 / AV_TIME_BASE;
1464     av_dict_set(&s->metadata, "title", matroska->title, 0);
1465
1466     if (matroska->date_utc.size == 8)
1467         matroska_metadata_creation_time(&s->metadata, AV_RB64(matroska->date_utc.data));
1468
1469     tracks = matroska->tracks.elem;
1470     for (i=0; i < matroska->tracks.nb_elem; i++) {
1471         MatroskaTrack *track = &tracks[i];
1472         enum CodecID codec_id = CODEC_ID_NONE;
1473         EbmlList *encodings_list = &track->encodings;
1474         MatroskaTrackEncoding *encodings = encodings_list->elem;
1475         uint8_t *extradata = NULL;
1476         int extradata_size = 0;
1477         int extradata_offset = 0;
1478         uint32_t fourcc = 0;
1479         AVIOContext b;
1480
1481         /* Apply some sanity checks. */
1482         if (track->type != MATROSKA_TRACK_TYPE_VIDEO &&
1483             track->type != MATROSKA_TRACK_TYPE_AUDIO &&
1484             track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
1485             av_log(matroska->ctx, AV_LOG_INFO,
1486                    "Unknown or unsupported track type %"PRIu64"\n",
1487                    track->type);
1488             continue;
1489         }
1490         if (track->codec_id == NULL)
1491             continue;
1492
1493         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1494             if (!track->default_duration && track->video.frame_rate > 0)
1495                 track->default_duration = 1000000000/track->video.frame_rate;
1496             if (!track->video.display_width)
1497                 track->video.display_width = track->video.pixel_width;
1498             if (!track->video.display_height)
1499                 track->video.display_height = track->video.pixel_height;
1500             if (track->video.color_space.size == 4)
1501                 fourcc = AV_RL32(track->video.color_space.data);
1502         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1503             if (!track->audio.out_samplerate)
1504                 track->audio.out_samplerate = track->audio.samplerate;
1505         }
1506         if (encodings_list->nb_elem > 1) {
1507             av_log(matroska->ctx, AV_LOG_ERROR,
1508                    "Multiple combined encodings not supported");
1509         } else if (encodings_list->nb_elem == 1) {
1510             if (encodings[0].type ||
1511                 (encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP &&
1512 #if CONFIG_ZLIB
1513                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_ZLIB &&
1514 #endif
1515 #if CONFIG_BZLIB
1516                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_BZLIB &&
1517 #endif
1518                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_LZO)) {
1519                 encodings[0].scope = 0;
1520                 av_log(matroska->ctx, AV_LOG_ERROR,
1521                        "Unsupported encoding type");
1522             } else if (track->codec_priv.size && encodings[0].scope&2) {
1523                 uint8_t *codec_priv = track->codec_priv.data;
1524                 int offset = matroska_decode_buffer(&track->codec_priv.data,
1525                                                     &track->codec_priv.size,
1526                                                     track);
1527                 if (offset < 0) {
1528                     track->codec_priv.data = NULL;
1529                     track->codec_priv.size = 0;
1530                     av_log(matroska->ctx, AV_LOG_ERROR,
1531                            "Failed to decode codec private data\n");
1532                 } else if (offset > 0) {
1533                     track->codec_priv.data = av_malloc(track->codec_priv.size + offset);
1534                     memcpy(track->codec_priv.data,
1535                            encodings[0].compression.settings.data, offset);
1536                     memcpy(track->codec_priv.data+offset, codec_priv,
1537                            track->codec_priv.size);
1538                     track->codec_priv.size += offset;
1539                 }
1540                 if (codec_priv != track->codec_priv.data)
1541                     av_free(codec_priv);
1542             }
1543         }
1544
1545         for(j=0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++){
1546             if(!strncmp(ff_mkv_codec_tags[j].str, track->codec_id,
1547                         strlen(ff_mkv_codec_tags[j].str))){
1548                 codec_id= ff_mkv_codec_tags[j].id;
1549                 break;
1550             }
1551         }
1552
1553         st = track->stream = avformat_new_stream(s, NULL);
1554         if (st == NULL)
1555             return AVERROR(ENOMEM);
1556
1557         if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC")
1558             && track->codec_priv.size >= 40
1559             && track->codec_priv.data != NULL) {
1560             track->ms_compat = 1;
1561             fourcc = AV_RL32(track->codec_priv.data + 16);
1562             codec_id = ff_codec_get_id(ff_codec_bmp_tags, fourcc);
1563             extradata_offset = 40;
1564         } else if (!strcmp(track->codec_id, "A_MS/ACM")
1565                    && track->codec_priv.size >= 14
1566                    && track->codec_priv.data != NULL) {
1567             int ret;
1568             ffio_init_context(&b, track->codec_priv.data, track->codec_priv.size,
1569                           AVIO_FLAG_READ, NULL, NULL, NULL, NULL);
1570             ret = ff_get_wav_header(&b, st->codec, track->codec_priv.size);
1571             if (ret < 0)
1572                 return ret;
1573             codec_id = st->codec->codec_id;
1574             extradata_offset = FFMIN(track->codec_priv.size, 18);
1575         } else if (!strcmp(track->codec_id, "V_QUICKTIME")
1576                    && (track->codec_priv.size >= 86)
1577                    && (track->codec_priv.data != NULL)) {
1578             fourcc = AV_RL32(track->codec_priv.data);
1579             codec_id = ff_codec_get_id(ff_codec_movvideo_tags, fourcc);
1580         } else if (codec_id == CODEC_ID_PCM_S16BE) {
1581             switch (track->audio.bitdepth) {
1582             case  8:  codec_id = CODEC_ID_PCM_U8;     break;
1583             case 24:  codec_id = CODEC_ID_PCM_S24BE;  break;
1584             case 32:  codec_id = CODEC_ID_PCM_S32BE;  break;
1585             }
1586         } else if (codec_id == CODEC_ID_PCM_S16LE) {
1587             switch (track->audio.bitdepth) {
1588             case  8:  codec_id = CODEC_ID_PCM_U8;     break;
1589             case 24:  codec_id = CODEC_ID_PCM_S24LE;  break;
1590             case 32:  codec_id = CODEC_ID_PCM_S32LE;  break;
1591             }
1592         } else if (codec_id==CODEC_ID_PCM_F32LE && track->audio.bitdepth==64) {
1593             codec_id = CODEC_ID_PCM_F64LE;
1594         } else if (codec_id == CODEC_ID_AAC && !track->codec_priv.size) {
1595             int profile = matroska_aac_profile(track->codec_id);
1596             int sri = matroska_aac_sri(track->audio.samplerate);
1597             extradata = av_mallocz(5 + FF_INPUT_BUFFER_PADDING_SIZE);
1598             if (extradata == NULL)
1599                 return AVERROR(ENOMEM);
1600             extradata[0] = (profile << 3) | ((sri&0x0E) >> 1);
1601             extradata[1] = ((sri&0x01) << 7) | (track->audio.channels<<3);
1602             if (strstr(track->codec_id, "SBR")) {
1603                 sri = matroska_aac_sri(track->audio.out_samplerate);
1604                 extradata[2] = 0x56;
1605                 extradata[3] = 0xE5;
1606                 extradata[4] = 0x80 | (sri<<3);
1607                 extradata_size = 5;
1608             } else
1609                 extradata_size = 2;
1610         } else if (codec_id == CODEC_ID_TTA) {
1611             extradata_size = 30;
1612             extradata = av_mallocz(extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
1613             if (extradata == NULL)
1614                 return AVERROR(ENOMEM);
1615             ffio_init_context(&b, extradata, extradata_size, 1,
1616                           NULL, NULL, NULL, NULL);
1617             avio_write(&b, "TTA1", 4);
1618             avio_wl16(&b, 1);
1619             avio_wl16(&b, track->audio.channels);
1620             avio_wl16(&b, track->audio.bitdepth);
1621             avio_wl32(&b, track->audio.out_samplerate);
1622             avio_wl32(&b, matroska->ctx->duration * track->audio.out_samplerate);
1623         } else if (codec_id == CODEC_ID_RV10 || codec_id == CODEC_ID_RV20 ||
1624                    codec_id == CODEC_ID_RV30 || codec_id == CODEC_ID_RV40) {
1625             extradata_offset = 26;
1626         } else if (codec_id == CODEC_ID_RA_144) {
1627             track->audio.out_samplerate = 8000;
1628             track->audio.channels = 1;
1629         } else if ((codec_id == CODEC_ID_RA_288 || codec_id == CODEC_ID_COOK ||
1630                     codec_id == CODEC_ID_ATRAC3 || codec_id == CODEC_ID_SIPR)
1631                     && track->codec_priv.data) {
1632             int flavor;
1633
1634             ffio_init_context(&b, track->codec_priv.data,track->codec_priv.size,
1635                           0, NULL, NULL, NULL, NULL);
1636             avio_skip(&b, 22);
1637             flavor                       = avio_rb16(&b);
1638             track->audio.coded_framesize = avio_rb32(&b);
1639             avio_skip(&b, 12);
1640             track->audio.sub_packet_h    = avio_rb16(&b);
1641             track->audio.frame_size      = avio_rb16(&b);
1642             track->audio.sub_packet_size = avio_rb16(&b);
1643             track->audio.buf = av_malloc(track->audio.frame_size * track->audio.sub_packet_h);
1644             if (codec_id == CODEC_ID_RA_288) {
1645                 st->codec->block_align = track->audio.coded_framesize;
1646                 track->codec_priv.size = 0;
1647             } else {
1648                 if (codec_id == CODEC_ID_SIPR && flavor < 4) {
1649                     const int sipr_bit_rate[4] = { 6504, 8496, 5000, 16000 };
1650                     track->audio.sub_packet_size = ff_sipr_subpk_size[flavor];
1651                     st->codec->bit_rate = sipr_bit_rate[flavor];
1652                 }
1653                 st->codec->block_align = track->audio.sub_packet_size;
1654                 extradata_offset = 78;
1655             }
1656         }
1657         track->codec_priv.size -= extradata_offset;
1658
1659         if (codec_id == CODEC_ID_NONE)
1660             av_log(matroska->ctx, AV_LOG_INFO,
1661                    "Unknown/unsupported CodecID %s.\n", track->codec_id);
1662
1663         if (track->time_scale < 0.01)
1664             track->time_scale = 1.0;
1665         avpriv_set_pts_info(st, 64, matroska->time_scale*track->time_scale, 1000*1000*1000); /* 64 bit pts in ns */
1666
1667         st->codec->codec_id = codec_id;
1668         st->start_time = 0;
1669         if (strcmp(track->language, "und"))
1670             av_dict_set(&st->metadata, "language", track->language, 0);
1671         av_dict_set(&st->metadata, "title", track->name, 0);
1672
1673         if (track->flag_default)
1674             st->disposition |= AV_DISPOSITION_DEFAULT;
1675         if (track->flag_forced)
1676             st->disposition |= AV_DISPOSITION_FORCED;
1677
1678         if (!st->codec->extradata) {
1679             if(extradata){
1680                 st->codec->extradata = extradata;
1681                 st->codec->extradata_size = extradata_size;
1682             } else if(track->codec_priv.data && track->codec_priv.size > 0){
1683                 st->codec->extradata = av_mallocz(track->codec_priv.size +
1684                                                   FF_INPUT_BUFFER_PADDING_SIZE);
1685                 if(st->codec->extradata == NULL)
1686                     return AVERROR(ENOMEM);
1687                 st->codec->extradata_size = track->codec_priv.size;
1688                 memcpy(st->codec->extradata,
1689                        track->codec_priv.data + extradata_offset,
1690                        track->codec_priv.size);
1691             }
1692         }
1693
1694         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1695             MatroskaTrackPlane *planes = track->operation.combine_planes.elem;
1696
1697             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
1698             st->codec->codec_tag  = fourcc;
1699             st->codec->width  = track->video.pixel_width;
1700             st->codec->height = track->video.pixel_height;
1701             av_reduce(&st->sample_aspect_ratio.num,
1702                       &st->sample_aspect_ratio.den,
1703                       st->codec->height * track->video.display_width,
1704                       st->codec-> width * track->video.display_height,
1705                       255);
1706             st->need_parsing = AVSTREAM_PARSE_HEADERS;
1707             if (track->default_duration) {
1708                 av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
1709                           1000000000, track->default_duration, 30000);
1710 #if FF_API_R_FRAME_RATE
1711                 st->r_frame_rate = st->avg_frame_rate;
1712 #endif
1713             }
1714
1715             /* export stereo mode flag as metadata tag */
1716             if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREO_MODE_COUNT)
1717                 av_dict_set(&st->metadata, "stereo_mode", matroska_video_stereo_mode[track->video.stereo_mode], 0);
1718
1719             /* if we have virtual track, mark the real tracks */
1720             for (j=0; j < track->operation.combine_planes.nb_elem; j++) {
1721                 char buf[32];
1722                 if (planes[j].type >= MATROSKA_VIDEO_STEREO_PLANE_COUNT)
1723                     continue;
1724                 snprintf(buf, sizeof(buf), "%s_%d",
1725                          matroska_video_stereo_plane[planes[j].type], i);
1726                 for (k=0; k < matroska->tracks.nb_elem; k++)
1727                     if (planes[j].uid == tracks[k].uid) {
1728                         av_dict_set(&s->streams[k]->metadata,
1729                                     "stereo_mode", buf, 0);
1730                         break;
1731                     }
1732             }
1733         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1734             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
1735             st->codec->sample_rate = track->audio.out_samplerate;
1736             st->codec->channels = track->audio.channels;
1737             if (st->codec->codec_id != CODEC_ID_AAC)
1738             st->need_parsing = AVSTREAM_PARSE_HEADERS;
1739         } else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
1740             st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
1741             if (st->codec->codec_id == CODEC_ID_SSA)
1742                 matroska->contains_ssa = 1;
1743         }
1744     }
1745
1746     attachements = attachements_list->elem;
1747     for (j=0; j<attachements_list->nb_elem; j++) {
1748         if (!(attachements[j].filename && attachements[j].mime &&
1749               attachements[j].bin.data && attachements[j].bin.size > 0)) {
1750             av_log(matroska->ctx, AV_LOG_ERROR, "incomplete attachment\n");
1751         } else {
1752             AVStream *st = avformat_new_stream(s, NULL);
1753             if (st == NULL)
1754                 break;
1755             av_dict_set(&st->metadata, "filename",attachements[j].filename, 0);
1756             av_dict_set(&st->metadata, "mimetype", attachements[j].mime, 0);
1757             st->codec->codec_id = CODEC_ID_NONE;
1758             st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
1759             st->codec->extradata  = av_malloc(attachements[j].bin.size + FF_INPUT_BUFFER_PADDING_SIZE);
1760             if(st->codec->extradata == NULL)
1761                 break;
1762             st->codec->extradata_size = attachements[j].bin.size;
1763             memcpy(st->codec->extradata, attachements[j].bin.data, attachements[j].bin.size);
1764
1765             for (i=0; ff_mkv_mime_tags[i].id != CODEC_ID_NONE; i++) {
1766                 if (!strncmp(ff_mkv_mime_tags[i].str, attachements[j].mime,
1767                              strlen(ff_mkv_mime_tags[i].str))) {
1768                     st->codec->codec_id = ff_mkv_mime_tags[i].id;
1769                     break;
1770                 }
1771             }
1772             attachements[j].stream = st;
1773         }
1774     }
1775
1776     chapters = chapters_list->elem;
1777     for (i=0; i<chapters_list->nb_elem; i++)
1778         if (chapters[i].start != AV_NOPTS_VALUE && chapters[i].uid
1779             && (max_start==0 || chapters[i].start > max_start)) {
1780             chapters[i].chapter =
1781             avpriv_new_chapter(s, chapters[i].uid, (AVRational){1, 1000000000},
1782                            chapters[i].start, chapters[i].end,
1783                            chapters[i].title);
1784             av_dict_set(&chapters[i].chapter->metadata,
1785                              "title", chapters[i].title, 0);
1786             max_start = chapters[i].start;
1787         }
1788
1789     matroska_add_index_entries(matroska);
1790
1791     matroska_convert_tags(s);
1792
1793     return 0;
1794 }
1795
1796 /*
1797  * Put one packet in an application-supplied AVPacket struct.
1798  * Returns 0 on success or -1 on failure.
1799  */
1800 static int matroska_deliver_packet(MatroskaDemuxContext *matroska,
1801                                    AVPacket *pkt)
1802 {
1803     if (matroska->num_packets > 0) {
1804         memcpy(pkt, matroska->packets[0], sizeof(AVPacket));
1805         av_free(matroska->packets[0]);
1806         if (matroska->num_packets > 1) {
1807             void *newpackets;
1808             memmove(&matroska->packets[0], &matroska->packets[1],
1809                     (matroska->num_packets - 1) * sizeof(AVPacket *));
1810             newpackets = av_realloc(matroska->packets,
1811                             (matroska->num_packets - 1) * sizeof(AVPacket *));
1812             if (newpackets)
1813                 matroska->packets = newpackets;
1814         } else {
1815             av_freep(&matroska->packets);
1816             matroska->prev_pkt = NULL;
1817         }
1818         matroska->num_packets--;
1819         return 0;
1820     }
1821
1822     return -1;
1823 }
1824
1825 /*
1826  * Free all packets in our internal queue.
1827  */
1828 static void matroska_clear_queue(MatroskaDemuxContext *matroska)
1829 {
1830     if (matroska->packets) {
1831         int n;
1832         for (n = 0; n < matroska->num_packets; n++) {
1833             av_free_packet(matroska->packets[n]);
1834             av_free(matroska->packets[n]);
1835         }
1836         av_freep(&matroska->packets);
1837         matroska->num_packets = 0;
1838     }
1839 }
1840
1841 static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
1842                                 int size, int64_t pos, uint64_t cluster_time,
1843                                 uint64_t duration, int is_keyframe,
1844                                 int64_t cluster_pos)
1845 {
1846     uint64_t timecode = AV_NOPTS_VALUE;
1847     MatroskaTrack *track;
1848     int res = 0;
1849     AVStream *st;
1850     AVPacket *pkt;
1851     int16_t block_time;
1852     uint32_t *lace_size = NULL;
1853     int n, flags, laces = 0;
1854     uint64_t num;
1855
1856     if ((n = matroska_ebmlnum_uint(matroska, data, size, &num)) < 0) {
1857         av_log(matroska->ctx, AV_LOG_ERROR, "EBML block data error\n");
1858         return n;
1859     }
1860     data += n;
1861     size -= n;
1862
1863     track = matroska_find_track_by_num(matroska, num);
1864     if (!track || !track->stream) {
1865         av_log(matroska->ctx, AV_LOG_INFO,
1866                "Invalid stream %"PRIu64" or size %u\n", num, size);
1867         return AVERROR_INVALIDDATA;
1868     } else if (size <= 3)
1869         return 0;
1870     st = track->stream;
1871     if (st->discard >= AVDISCARD_ALL)
1872         return res;
1873     av_assert1(duration != AV_NOPTS_VALUE);
1874     if (!duration)
1875         duration = track->default_duration / matroska->time_scale;
1876
1877     block_time = AV_RB16(data);
1878     data += 2;
1879     flags = *data++;
1880     size -= 3;
1881     if (is_keyframe == -1)
1882         is_keyframe = flags & 0x80 ? AV_PKT_FLAG_KEY : 0;
1883
1884     if (cluster_time != (uint64_t)-1
1885         && (block_time >= 0 || cluster_time >= -block_time)) {
1886         timecode = cluster_time + block_time;
1887         if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE
1888             && timecode < track->end_timecode)
1889             is_keyframe = 0;  /* overlapping subtitles are not key frame */
1890         if (is_keyframe)
1891             av_add_index_entry(st, cluster_pos, timecode, 0,0,AVINDEX_KEYFRAME);
1892         track->end_timecode = FFMAX(track->end_timecode, timecode+duration);
1893     }
1894
1895     if (matroska->skip_to_keyframe && track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
1896         if (timecode < matroska->skip_to_timecode)
1897             return res;
1898         if (!st->skip_to_keyframe) {
1899             av_log(matroska->ctx, AV_LOG_ERROR, "File is broken, keyframes not correctly marked!\n");
1900             matroska->skip_to_keyframe = 0;
1901         }
1902         if (is_keyframe)
1903             matroska->skip_to_keyframe = 0;
1904     }
1905
1906     switch ((flags & 0x06) >> 1) {
1907         case 0x0: /* no lacing */
1908             laces = 1;
1909             lace_size = av_mallocz(sizeof(int));
1910             lace_size[0] = size;
1911             break;
1912
1913         case 0x1: /* Xiph lacing */
1914         case 0x2: /* fixed-size lacing */
1915         case 0x3: /* EBML lacing */
1916             av_assert0(size>0); // size <=3 is checked before size-=3 above
1917             laces = (*data) + 1;
1918             data += 1;
1919             size -= 1;
1920             lace_size = av_mallocz(laces * sizeof(int));
1921
1922             switch ((flags & 0x06) >> 1) {
1923                 case 0x1: /* Xiph lacing */ {
1924                     uint8_t temp;
1925                     uint32_t total = 0;
1926                     for (n = 0; res == 0 && n < laces - 1; n++) {
1927                         while (1) {
1928                             if (size == 0) {
1929                                 res = -1;
1930                                 break;
1931                             }
1932                             temp = *data;
1933                             lace_size[n] += temp;
1934                             data += 1;
1935                             size -= 1;
1936                             if (temp != 0xff)
1937                                 break;
1938                         }
1939                         total += lace_size[n];
1940                     }
1941                     lace_size[n] = size - total;
1942                     break;
1943                 }
1944
1945                 case 0x2: /* fixed-size lacing */
1946                     for (n = 0; n < laces; n++)
1947                         lace_size[n] = size / laces;
1948                     break;
1949
1950                 case 0x3: /* EBML lacing */ {
1951                     uint32_t total;
1952                     n = matroska_ebmlnum_uint(matroska, data, size, &num);
1953                     if (n < 0) {
1954                         av_log(matroska->ctx, AV_LOG_INFO,
1955                                "EBML block data error\n");
1956                         break;
1957                     }
1958                     data += n;
1959                     size -= n;
1960                     total = lace_size[0] = num;
1961                     for (n = 1; res == 0 && n < laces - 1; n++) {
1962                         int64_t snum;
1963                         int r;
1964                         r = matroska_ebmlnum_sint(matroska, data, size, &snum);
1965                         if (r < 0) {
1966                             av_log(matroska->ctx, AV_LOG_INFO,
1967                                    "EBML block data error\n");
1968                             break;
1969                         }
1970                         data += r;
1971                         size -= r;
1972                         lace_size[n] = lace_size[n - 1] + snum;
1973                         total += lace_size[n];
1974                     }
1975                     lace_size[laces - 1] = size - total;
1976                     break;
1977                 }
1978             }
1979             break;
1980     }
1981
1982     if (res == 0) {
1983         for (n = 0; n < laces; n++) {
1984             if (lace_size[n] > size) {
1985                 av_log(matroska->ctx, AV_LOG_ERROR, "Invalid packet size\n");
1986                 break;
1987             }
1988
1989             if ((st->codec->codec_id == CODEC_ID_RA_288 ||
1990                  st->codec->codec_id == CODEC_ID_COOK ||
1991                  st->codec->codec_id == CODEC_ID_SIPR ||
1992                  st->codec->codec_id == CODEC_ID_ATRAC3) &&
1993                  st->codec->block_align && track->audio.sub_packet_size) {
1994                 int a = st->codec->block_align;
1995                 int sps = track->audio.sub_packet_size;
1996                 int cfs = track->audio.coded_framesize;
1997                 int h = track->audio.sub_packet_h;
1998                 int y = track->audio.sub_packet_cnt;
1999                 int w = track->audio.frame_size;
2000                 int x;
2001
2002                 if (!track->audio.pkt_cnt) {
2003                     if (track->audio.sub_packet_cnt == 0)
2004                         track->audio.buf_timecode = timecode;
2005                     if (st->codec->codec_id == CODEC_ID_RA_288) {
2006                         if (size < cfs * h / 2) {
2007                             av_log(matroska->ctx, AV_LOG_ERROR,
2008                                    "Corrupt int4 RM-style audio packet size\n");
2009                             res = AVERROR_INVALIDDATA;
2010                             goto end;
2011                         }
2012                         for (x=0; x<h/2; x++)
2013                             memcpy(track->audio.buf+x*2*w+y*cfs,
2014                                    data+x*cfs, cfs);
2015                     } else if (st->codec->codec_id == CODEC_ID_SIPR) {
2016                         if (size < w) {
2017                             av_log(matroska->ctx, AV_LOG_ERROR,
2018                                    "Corrupt sipr RM-style audio packet size\n");
2019                             res = AVERROR_INVALIDDATA;
2020                             goto end;
2021                         }
2022                         memcpy(track->audio.buf + y*w, data, w);
2023                     } else {
2024                         if (size < sps * w / sps) {
2025                             av_log(matroska->ctx, AV_LOG_ERROR,
2026                                    "Corrupt generic RM-style audio packet size\n");
2027                             res = AVERROR_INVALIDDATA;
2028                             goto end;
2029                         }
2030                         for (x=0; x<w/sps; x++)
2031                             memcpy(track->audio.buf+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), data+x*sps, sps);
2032                     }
2033
2034                     if (++track->audio.sub_packet_cnt >= h) {
2035                         if (st->codec->codec_id == CODEC_ID_SIPR)
2036                             ff_rm_reorder_sipr_data(track->audio.buf, h, w);
2037                         track->audio.sub_packet_cnt = 0;
2038                         track->audio.pkt_cnt = h*w / a;
2039                     }
2040                 }
2041                 while (track->audio.pkt_cnt) {
2042                     pkt = av_mallocz(sizeof(AVPacket));
2043                     av_new_packet(pkt, a);
2044                     memcpy(pkt->data, track->audio.buf
2045                            + a * (h*w / a - track->audio.pkt_cnt--), a);
2046                     pkt->pts = track->audio.buf_timecode;
2047                     track->audio.buf_timecode = AV_NOPTS_VALUE;
2048                     pkt->pos = pos;
2049                     pkt->stream_index = st->index;
2050                     dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
2051                 }
2052             } else {
2053                 MatroskaTrackEncoding *encodings = track->encodings.elem;
2054                 int offset = 0;
2055                 uint32_t pkt_size = lace_size[n];
2056                 uint8_t *pkt_data = data;
2057
2058                 if (encodings && encodings->scope & 1) {
2059                     offset = matroska_decode_buffer(&pkt_data,&pkt_size, track);
2060                     if (offset < 0)
2061                         continue;
2062                     av_assert0(offset + pkt_size >= pkt_size);
2063                 }
2064
2065                 pkt = av_mallocz(sizeof(AVPacket));
2066                 /* XXX: prevent data copy... */
2067                 if (av_new_packet(pkt, pkt_size+offset) < 0) {
2068                     av_free(pkt);
2069                     res = AVERROR(ENOMEM);
2070                     break;
2071                 }
2072                 if (offset)
2073                     memcpy (pkt->data, encodings->compression.settings.data, offset);
2074                 memcpy (pkt->data+offset, pkt_data, pkt_size);
2075
2076                 if (pkt_data != data)
2077                     av_free(pkt_data);
2078
2079                 if (n == 0)
2080                     pkt->flags = is_keyframe;
2081                 pkt->stream_index = st->index;
2082
2083                 if (track->ms_compat)
2084                     pkt->dts = timecode;
2085                 else
2086                     pkt->pts = timecode;
2087                 pkt->pos = pos;
2088                 if (st->codec->codec_id == CODEC_ID_TEXT)
2089                     pkt->convergence_duration = duration;
2090                 else if (track->type != MATROSKA_TRACK_TYPE_SUBTITLE)
2091                     pkt->duration = duration;
2092
2093                 if (st->codec->codec_id == CODEC_ID_SSA)
2094                     matroska_fix_ass_packet(matroska, pkt, duration);
2095
2096                 if (matroska->prev_pkt &&
2097                     timecode != AV_NOPTS_VALUE &&
2098                     matroska->prev_pkt->pts == timecode &&
2099                     matroska->prev_pkt->stream_index == st->index &&
2100                     st->codec->codec_id == CODEC_ID_SSA)
2101                     matroska_merge_packets(matroska->prev_pkt, pkt);
2102                 else {
2103                     dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
2104                     matroska->prev_pkt = pkt;
2105                 }
2106             }
2107
2108             if (timecode != AV_NOPTS_VALUE)
2109                 timecode = duration ? timecode + duration : AV_NOPTS_VALUE;
2110             data += lace_size[n];
2111             size -= lace_size[n];
2112         }
2113     }
2114
2115 end:
2116     av_free(lace_size);
2117     return res;
2118 }
2119
2120 static int matroska_parse_cluster_incremental(MatroskaDemuxContext *matroska)
2121 {
2122     EbmlList *blocks_list;
2123     MatroskaBlock *blocks;
2124     int i, res;
2125     res = ebml_parse(matroska,
2126                      matroska_cluster_incremental_parsing,
2127                      &matroska->current_cluster);
2128     if (res == 1) {
2129         /* New Cluster */
2130         if (matroska->current_cluster_pos)
2131             ebml_level_end(matroska);
2132         ebml_free(matroska_cluster, &matroska->current_cluster);
2133         memset(&matroska->current_cluster, 0, sizeof(MatroskaCluster));
2134         matroska->current_cluster_num_blocks = 0;
2135         matroska->current_cluster_pos = avio_tell(matroska->ctx->pb);
2136         matroska->prev_pkt = NULL;
2137         /* sizeof the ID which was already read */
2138         if (matroska->current_id)
2139             matroska->current_cluster_pos -= 4;
2140         res = ebml_parse(matroska,
2141                          matroska_clusters_incremental,
2142                          &matroska->current_cluster);
2143         /* Try parsing the block again. */
2144         if (res == 1)
2145             res = ebml_parse(matroska,
2146                              matroska_cluster_incremental_parsing,
2147                              &matroska->current_cluster);
2148     }
2149
2150     if (!res &&
2151         matroska->current_cluster_num_blocks <
2152             matroska->current_cluster.blocks.nb_elem) {
2153         blocks_list = &matroska->current_cluster.blocks;
2154         blocks = blocks_list->elem;
2155
2156         matroska->current_cluster_num_blocks = blocks_list->nb_elem;
2157         i = blocks_list->nb_elem - 1;
2158         if (blocks[i].bin.size > 0 && blocks[i].bin.data) {
2159             int is_keyframe = blocks[i].non_simple ? !blocks[i].reference : -1;
2160             if (!blocks[i].non_simple)
2161                 blocks[i].duration = 0;
2162             res = matroska_parse_block(matroska,
2163                                        blocks[i].bin.data, blocks[i].bin.size,
2164                                        blocks[i].bin.pos,
2165                                        matroska->current_cluster.timecode,
2166                                        blocks[i].duration, is_keyframe,
2167                                        matroska->current_cluster_pos);
2168         }
2169     }
2170
2171     if (res < 0)  matroska->done = 1;
2172     return res;
2173 }
2174
2175 static int matroska_parse_cluster(MatroskaDemuxContext *matroska)
2176 {
2177     MatroskaCluster cluster = { 0 };
2178     EbmlList *blocks_list;
2179     MatroskaBlock *blocks;
2180     int i, res;
2181     int64_t pos;
2182     if (!matroska->contains_ssa)
2183         return matroska_parse_cluster_incremental(matroska);
2184     pos = avio_tell(matroska->ctx->pb);
2185     matroska->prev_pkt = NULL;
2186     if (matroska->current_id)
2187         pos -= 4;  /* sizeof the ID which was already read */
2188     res = ebml_parse(matroska, matroska_clusters, &cluster);
2189     blocks_list = &cluster.blocks;
2190     blocks = blocks_list->elem;
2191     for (i=0; i<blocks_list->nb_elem; i++)
2192         if (blocks[i].bin.size > 0 && blocks[i].bin.data) {
2193             int is_keyframe = blocks[i].non_simple ? !blocks[i].reference : -1;
2194             res=matroska_parse_block(matroska,
2195                                      blocks[i].bin.data, blocks[i].bin.size,
2196                                      blocks[i].bin.pos,  cluster.timecode,
2197                                      blocks[i].duration, is_keyframe,
2198                                      pos);
2199         }
2200     ebml_free(matroska_cluster, &cluster);
2201     return res;
2202 }
2203
2204 static int matroska_read_packet(AVFormatContext *s, AVPacket *pkt)
2205 {
2206     MatroskaDemuxContext *matroska = s->priv_data;
2207
2208     while (matroska_deliver_packet(matroska, pkt)) {
2209         int64_t pos = avio_tell(matroska->ctx->pb);
2210         if (matroska->done)
2211             return AVERROR_EOF;
2212         if (matroska_parse_cluster(matroska) < 0)
2213             matroska_resync(matroska, pos);
2214     }
2215
2216     return 0;
2217 }
2218
2219 static int matroska_read_seek(AVFormatContext *s, int stream_index,
2220                               int64_t timestamp, int flags)
2221 {
2222     MatroskaDemuxContext *matroska = s->priv_data;
2223     MatroskaTrack *tracks = matroska->tracks.elem;
2224     AVStream *st = s->streams[stream_index];
2225     int i, index, index_sub, index_min;
2226
2227     /* Parse the CUES now since we need the index data to seek. */
2228     if (matroska->cues_parsing_deferred > 0) {
2229         matroska->cues_parsing_deferred = 0;
2230         matroska_parse_cues(matroska);
2231     }
2232
2233     if (!st->nb_index_entries)
2234         goto err;
2235     timestamp = FFMAX(timestamp, st->index_entries[0].timestamp);
2236
2237     if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
2238         avio_seek(s->pb, st->index_entries[st->nb_index_entries-1].pos, SEEK_SET);
2239         matroska->current_id = 0;
2240         while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
2241             matroska->prev_pkt = NULL;
2242             matroska_clear_queue(matroska);
2243             if (matroska_parse_cluster(matroska) < 0)
2244                 break;
2245         }
2246     }
2247
2248     matroska_clear_queue(matroska);
2249     if (index < 0 || (matroska->cues_parsing_deferred < 0 && index == st->nb_index_entries - 1))
2250         goto err;
2251
2252     index_min = index;
2253     for (i=0; i < matroska->tracks.nb_elem; i++) {
2254         tracks[i].audio.pkt_cnt = 0;
2255         tracks[i].audio.sub_packet_cnt = 0;
2256         tracks[i].audio.buf_timecode = AV_NOPTS_VALUE;
2257         tracks[i].end_timecode = 0;
2258         if (tracks[i].type == MATROSKA_TRACK_TYPE_SUBTITLE
2259             && !tracks[i].stream->discard != AVDISCARD_ALL) {
2260             index_sub = av_index_search_timestamp(tracks[i].stream, st->index_entries[index].timestamp, AVSEEK_FLAG_BACKWARD);
2261             if (index_sub >= 0
2262                 && st->index_entries[index_sub].pos < st->index_entries[index_min].pos
2263                 && st->index_entries[index].timestamp - st->index_entries[index_sub].timestamp < 30000000000/matroska->time_scale)
2264                 index_min = index_sub;
2265         }
2266     }
2267
2268     avio_seek(s->pb, st->index_entries[index_min].pos, SEEK_SET);
2269     matroska->current_id = 0;
2270     st->skip_to_keyframe =
2271     matroska->skip_to_keyframe = !(flags & AVSEEK_FLAG_ANY);
2272     matroska->skip_to_timecode = st->index_entries[index].timestamp;
2273     matroska->done = 0;
2274     matroska->num_levels = 0;
2275     ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
2276     return 0;
2277 err:
2278     // slightly hackish but allows proper fallback to
2279     // the generic seeking code.
2280     matroska_clear_queue(matroska);
2281     matroska->current_id = 0;
2282     st->skip_to_keyframe =
2283     matroska->skip_to_keyframe = 0;
2284     matroska->done = 0;
2285     matroska->num_levels = 0;
2286     return -1;
2287 }
2288
2289 static int matroska_read_close(AVFormatContext *s)
2290 {
2291     MatroskaDemuxContext *matroska = s->priv_data;
2292     MatroskaTrack *tracks = matroska->tracks.elem;
2293     int n;
2294
2295     matroska_clear_queue(matroska);
2296
2297     for (n=0; n < matroska->tracks.nb_elem; n++)
2298         if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)
2299             av_free(tracks[n].audio.buf);
2300     ebml_free(matroska_cluster, &matroska->current_cluster);
2301     ebml_free(matroska_segment, matroska);
2302
2303     return 0;
2304 }
2305
2306 AVInputFormat ff_matroska_demuxer = {
2307     .name           = "matroska,webm",
2308     .long_name      = NULL_IF_CONFIG_SMALL("Matroska / WebM"),
2309     .priv_data_size = sizeof(MatroskaDemuxContext),
2310     .read_probe     = matroska_probe,
2311     .read_header    = matroska_read_header,
2312     .read_packet    = matroska_read_packet,
2313     .read_close     = matroska_read_close,
2314     .read_seek      = matroska_read_seek,
2315 };