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 "rmsipr.h"
  39 #include "matroska.h"
  40 #include "libavcodec/bytestream.h"
  41 #include "libavcodec/mpeg4audio.h"
  42 #include "libavutil/base64.h"
  43 #include "libavutil/intfloat.h"
  44 #include "libavutil/intreadwrite.h"
  45 #include "libavutil/avstring.h"
  46 #include "libavutil/lzo.h"
  47 #include "libavutil/dict.h"
  48 #if CONFIG_ZLIB
  49 #include <zlib.h>
  50 #endif
  51 #if CONFIG_BZLIB
  52 #include <bzlib.h>
  53 #endif
  54
  55 typedef enum {
  56     EBML_NONE,
  57     EBML_UINT,
  58     EBML_FLOAT,
  59     EBML_STR,
  60     EBML_UTF8,
  61     EBML_BIN,
  62     EBML_NEST,
  63     EBML_PASS,
  64     EBML_STOP,
  65     EBML_SINT,
  66     EBML_TYPE_COUNT
  67 } EbmlType;
  68
  69 typedef const struct EbmlSyntax {
  70     uint32_t id;
  71     EbmlType type;
  72     int list_elem_size;
  73     int data_offset;
  74     union {
  75         uint64_t    u;
  76         double      f;
  77         const char *s;
  78         const struct EbmlSyntax *n;
  79     } def;
  80 } EbmlSyntax;
  81
  82 typedef struct {
  83     int nb_elem;
  84     void *elem;
  85 } EbmlList;
  86
  87 typedef struct {
  88     int      size;
  89     uint8_t *data;
  90     int64_t  pos;
  91 } EbmlBin;
  92
  93 typedef struct {
  94     uint64_t version;
  95     uint64_t max_size;
  96     uint64_t id_length;
  97     char    *doctype;
  98     uint64_t doctype_version;
  99 } Ebml;
 100
 101 typedef struct {
 102     uint64_t algo;
 103     EbmlBin  settings;
 104 } MatroskaTrackCompression;
 105
 106 typedef struct {
 107     uint64_t algo;
 108     EbmlBin  key_id;
 109 } MatroskaTrackEncryption;
 110
 111 typedef struct {
 112     uint64_t scope;
 113     uint64_t type;
 114     MatroskaTrackCompression compression;
 115     MatroskaTrackEncryption encryption;
 116 } MatroskaTrackEncoding;
 117
 118 typedef struct {
 119     double   frame_rate;
 120     uint64_t display_width;
 121     uint64_t display_height;
 122     uint64_t pixel_width;
 123     uint64_t pixel_height;
 124     EbmlBin color_space;
 125     uint64_t stereo_mode;
 126     uint64_t alpha_mode;
 127 } MatroskaTrackVideo;
 128
 129 typedef struct {
 130     double   samplerate;
 131     double   out_samplerate;
 132     uint64_t bitdepth;
 133     uint64_t channels;
 134
 135     /* real audio header (extracted from extradata) */
 136     int      coded_framesize;
 137     int      sub_packet_h;
 138     int      frame_size;
 139     int      sub_packet_size;
 140     int      sub_packet_cnt;
 141     int      pkt_cnt;
 142     uint64_t buf_timecode;
 143     uint8_t *buf;
 144 } MatroskaTrackAudio;
 145
 146 typedef struct {
 147     uint64_t uid;
 148     uint64_t type;
 149 } MatroskaTrackPlane;
 150
 151 typedef struct {
 152     EbmlList combine_planes;
 153 } MatroskaTrackOperation;
 154
 155 typedef struct {
 156     uint64_t num;
 157     uint64_t uid;
 158     uint64_t type;
 159     char    *name;
 160     char    *codec_id;
 161     EbmlBin  codec_priv;
 162     char    *language;
 163     double time_scale;
 164     uint64_t default_duration;
 165     uint64_t flag_default;
 166     uint64_t flag_forced;
 167     uint64_t codec_delay;
 168     uint64_t seek_preroll;
 169     MatroskaTrackVideo video;
 170     MatroskaTrackAudio audio;
 171     MatroskaTrackOperation operation;
 172     EbmlList encodings;
 173
 174     AVStream *stream;
 175     int64_t end_timecode;
 176     int ms_compat;
 177     uint64_t max_block_additional_id;
 178 } MatroskaTrack;
 179
 180 typedef struct {
 181     uint64_t uid;
 182     char *filename;
 183     char *mime;
 184     EbmlBin bin;
 185
 186     AVStream *stream;
 187 } MatroskaAttachement;
 188
 189 typedef struct {
 190     uint64_t start;
 191     uint64_t end;
 192     uint64_t uid;
 193     char    *title;
 194
 195     AVChapter *chapter;
 196 } MatroskaChapter;
 197
 198 typedef struct {
 199     uint64_t track;
 200     uint64_t pos;
 201 } MatroskaIndexPos;
 202
 203 typedef struct {
 204     uint64_t time;
 205     EbmlList pos;
 206 } MatroskaIndex;
 207
 208 typedef struct {
 209     char *name;
 210     char *string;
 211     char *lang;
 212     uint64_t def;
 213     EbmlList sub;
 214 } MatroskaTag;
 215
 216 typedef struct {
 217     char    *type;
 218     uint64_t typevalue;
 219     uint64_t trackuid;
 220     uint64_t chapteruid;
 221     uint64_t attachuid;
 222 } MatroskaTagTarget;
 223
 224 typedef struct {
 225     MatroskaTagTarget target;
 226     EbmlList tag;
 227 } MatroskaTags;
 228
 229 typedef struct {
 230     uint64_t id;
 231     uint64_t pos;
 232 } MatroskaSeekhead;
 233
 234 typedef struct {
 235     uint64_t start;
 236     uint64_t length;
 237 } MatroskaLevel;
 238
 239 typedef struct {
 240     uint64_t timecode;
 241     EbmlList blocks;
 242 } MatroskaCluster;
 243
 244 typedef struct {
 245     AVFormatContext *ctx;
 246
 247     /* EBML stuff */
 248     int num_levels;
 249     MatroskaLevel levels[EBML_MAX_DEPTH];
 250     int level_up;
 251     uint32_t current_id;
 252
 253     uint64_t time_scale;
 254     double   duration;
 255     char    *title;
 256     char    *muxingapp;
 257     EbmlBin date_utc;
 258     EbmlList tracks;
 259     EbmlList attachments;
 260     EbmlList chapters;
 261     EbmlList index;
 262     EbmlList tags;
 263     EbmlList seekhead;
 264
 265     /* byte position of the segment inside the stream */
 266     int64_t segment_start;
 267
 268     /* the packet queue */
 269     AVPacket **packets;
 270     int num_packets;
 271     AVPacket *prev_pkt;
 272
 273     int done;
 274
 275     /* What to skip before effectively reading a packet. */
 276     int skip_to_keyframe;
 277     uint64_t skip_to_timecode;
 278
 279     /* File has a CUES element, but we defer parsing until it is needed. */
 280     int cues_parsing_deferred;
 281
 282     int current_cluster_num_blocks;
 283     int64_t current_cluster_pos;
 284     MatroskaCluster current_cluster;
 285
 286     /* File has SSA subtitles which prevent incremental cluster parsing. */
 287     int contains_ssa;
 288 } MatroskaDemuxContext;
 289
 290 typedef struct {
 291     uint64_t duration;
 292     int64_t  reference;
 293     uint64_t non_simple;
 294     EbmlBin  bin;
 295     uint64_t additional_id;
 296     EbmlBin  additional;
 297     int64_t discard_padding;
 298 } MatroskaBlock;
 299
 300 static EbmlSyntax ebml_header[] = {
 301     { EBML_ID_EBMLREADVERSION,        EBML_UINT, 0, offsetof(Ebml,version), {.u=EBML_VERSION} },
 302     { EBML_ID_EBMLMAXSIZELENGTH,      EBML_UINT, 0, offsetof(Ebml,max_size), {.u=8} },
 303     { EBML_ID_EBMLMAXIDLENGTH,        EBML_UINT, 0, offsetof(Ebml,id_length), {.u=4} },
 304     { EBML_ID_DOCTYPE,                EBML_STR,  0, offsetof(Ebml,doctype), {.s="(none)"} },
 305     { EBML_ID_DOCTYPEREADVERSION,     EBML_UINT, 0, offsetof(Ebml,doctype_version), {.u=1} },
 306     { EBML_ID_EBMLVERSION,            EBML_NONE },
 307     { EBML_ID_DOCTYPEVERSION,         EBML_NONE },
 308     { 0 }
 309 };
 310
 311 static EbmlSyntax ebml_syntax[] = {
 312     { EBML_ID_HEADER,                 EBML_NEST, 0, 0, {.n=ebml_header} },
 313     { 0 }
 314 };
 315
 316 static EbmlSyntax matroska_info[] = {
 317     { MATROSKA_ID_TIMECODESCALE,      EBML_UINT,  0, offsetof(MatroskaDemuxContext,time_scale), {.u=1000000} },
 318     { MATROSKA_ID_DURATION,           EBML_FLOAT, 0, offsetof(MatroskaDemuxContext,duration) },
 319     { MATROSKA_ID_TITLE,              EBML_UTF8,  0, offsetof(MatroskaDemuxContext,title) },
 320     { MATROSKA_ID_WRITINGAPP,         EBML_NONE },
 321     { MATROSKA_ID_MUXINGAPP,          EBML_UTF8, 0, offsetof(MatroskaDemuxContext,muxingapp) },
 322     { MATROSKA_ID_DATEUTC,            EBML_BIN,  0, offsetof(MatroskaDemuxContext,date_utc) },
 323     { MATROSKA_ID_SEGMENTUID,         EBML_NONE },
 324     { 0 }
 325 };
 326
 327 static EbmlSyntax matroska_track_video[] = {
 328     { MATROSKA_ID_VIDEOFRAMERATE,     EBML_FLOAT,0, offsetof(MatroskaTrackVideo,frame_rate) },
 329     { MATROSKA_ID_VIDEODISPLAYWIDTH,  EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_width), {.u=-1} },
 330     { MATROSKA_ID_VIDEODISPLAYHEIGHT, EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_height), {.u=-1} },
 331     { MATROSKA_ID_VIDEOPIXELWIDTH,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_width) },
 332     { MATROSKA_ID_VIDEOPIXELHEIGHT,   EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_height) },
 333     { MATROSKA_ID_VIDEOCOLORSPACE,    EBML_BIN,  0, offsetof(MatroskaTrackVideo,color_space) },
 334     { MATROSKA_ID_VIDEOSTEREOMODE,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,stereo_mode) },
 335     { MATROSKA_ID_VIDEOALPHAMODE,     EBML_UINT, 0, offsetof(MatroskaTrackVideo,alpha_mode) },
 336     { MATROSKA_ID_VIDEOPIXELCROPB,    EBML_NONE },
 337     { MATROSKA_ID_VIDEOPIXELCROPT,    EBML_NONE },
 338     { MATROSKA_ID_VIDEOPIXELCROPL,    EBML_NONE },
 339     { MATROSKA_ID_VIDEOPIXELCROPR,    EBML_NONE },
 340     { MATROSKA_ID_VIDEODISPLAYUNIT,   EBML_NONE },
 341     { MATROSKA_ID_VIDEOFLAGINTERLACED,EBML_NONE },
 342     { MATROSKA_ID_VIDEOASPECTRATIO,   EBML_NONE },
 343     { 0 }
 344 };
 345
 346 static EbmlSyntax matroska_track_audio[] = {
 347     { MATROSKA_ID_AUDIOSAMPLINGFREQ,  EBML_FLOAT,0, offsetof(MatroskaTrackAudio,samplerate), {.f=8000.0} },
 348     { MATROSKA_ID_AUDIOOUTSAMPLINGFREQ,EBML_FLOAT,0,offsetof(MatroskaTrackAudio,out_samplerate) },
 349     { MATROSKA_ID_AUDIOBITDEPTH,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,bitdepth) },
 350     { MATROSKA_ID_AUDIOCHANNELS,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,channels), {.u=1} },
 351     { 0 }
 352 };
 353
 354 static EbmlSyntax matroska_track_encoding_compression[] = {
 355     { MATROSKA_ID_ENCODINGCOMPALGO,   EBML_UINT, 0, offsetof(MatroskaTrackCompression,algo), {.u=0} },
 356     { MATROSKA_ID_ENCODINGCOMPSETTINGS,EBML_BIN, 0, offsetof(MatroskaTrackCompression,settings) },
 357     { 0 }
 358 };
 359
 360 static EbmlSyntax matroska_track_encoding_encryption[] = {
 361     { MATROSKA_ID_ENCODINGENCALGO,        EBML_UINT, 0, offsetof(MatroskaTrackEncryption,algo), {.u=0} },
 362     { MATROSKA_ID_ENCODINGENCKEYID,       EBML_BIN, 0, offsetof(MatroskaTrackEncryption,key_id) },
 363     { MATROSKA_ID_ENCODINGENCAESSETTINGS, EBML_NONE },
 364     { MATROSKA_ID_ENCODINGSIGALGO,        EBML_NONE },
 365     { MATROSKA_ID_ENCODINGSIGHASHALGO,    EBML_NONE },
 366     { MATROSKA_ID_ENCODINGSIGKEYID,       EBML_NONE },
 367     { MATROSKA_ID_ENCODINGSIGNATURE,      EBML_NONE },
 368     { 0 }
 369 };
 370 static EbmlSyntax matroska_track_encoding[] = {
 371     { MATROSKA_ID_ENCODINGSCOPE,      EBML_UINT, 0, offsetof(MatroskaTrackEncoding,scope), {.u=1} },
 372     { MATROSKA_ID_ENCODINGTYPE,       EBML_UINT, 0, offsetof(MatroskaTrackEncoding,type), {.u=0} },
 373     { MATROSKA_ID_ENCODINGCOMPRESSION,EBML_NEST, 0, offsetof(MatroskaTrackEncoding,compression), {.n=matroska_track_encoding_compression} },
 374     { MATROSKA_ID_ENCODINGENCRYPTION, EBML_NEST, 0, offsetof(MatroskaTrackEncoding,encryption), {.n=matroska_track_encoding_encryption} },
 375     { MATROSKA_ID_ENCODINGORDER,      EBML_NONE },
 376     { 0 }
 377 };
 378
 379 static EbmlSyntax matroska_track_encodings[] = {
 380     { MATROSKA_ID_TRACKCONTENTENCODING, EBML_NEST, sizeof(MatroskaTrackEncoding), offsetof(MatroskaTrack,encodings), {.n=matroska_track_encoding} },
 381     { 0 }
 382 };
 383
 384 static EbmlSyntax matroska_track_plane[] = {
 385     { MATROSKA_ID_TRACKPLANEUID,  EBML_UINT, 0, offsetof(MatroskaTrackPlane,uid) },
 386     { MATROSKA_ID_TRACKPLANETYPE, EBML_UINT, 0, offsetof(MatroskaTrackPlane,type) },
 387     { 0 }
 388 };
 389
 390 static EbmlSyntax matroska_track_combine_planes[] = {
 391     { MATROSKA_ID_TRACKPLANE, EBML_NEST, sizeof(MatroskaTrackPlane), offsetof(MatroskaTrackOperation,combine_planes), {.n=matroska_track_plane} },
 392     { 0 }
 393 };
 394
 395 static EbmlSyntax matroska_track_operation[] = {
 396     { MATROSKA_ID_TRACKCOMBINEPLANES, EBML_NEST, 0, 0, {.n=matroska_track_combine_planes} },
 397     { 0 }
 398 };
 399
 400 static EbmlSyntax matroska_track[] = {
 401     { MATROSKA_ID_TRACKNUMBER,          EBML_UINT, 0, offsetof(MatroskaTrack,num) },
 402     { MATROSKA_ID_TRACKNAME,            EBML_UTF8, 0, offsetof(MatroskaTrack,name) },
 403     { MATROSKA_ID_TRACKUID,             EBML_UINT, 0, offsetof(MatroskaTrack,uid) },
 404     { MATROSKA_ID_TRACKTYPE,            EBML_UINT, 0, offsetof(MatroskaTrack,type) },
 405     { MATROSKA_ID_CODECID,              EBML_STR,  0, offsetof(MatroskaTrack,codec_id) },
 406     { MATROSKA_ID_CODECPRIVATE,         EBML_BIN,  0, offsetof(MatroskaTrack,codec_priv) },
 407     { MATROSKA_ID_TRACKLANGUAGE,        EBML_UTF8, 0, offsetof(MatroskaTrack,language), {.s="eng"} },
 408     { MATROSKA_ID_TRACKDEFAULTDURATION, EBML_UINT, 0, offsetof(MatroskaTrack,default_duration) },
 409     { MATROSKA_ID_TRACKTIMECODESCALE,   EBML_FLOAT,0, offsetof(MatroskaTrack,time_scale), {.f=1.0} },
 410     { MATROSKA_ID_TRACKFLAGDEFAULT,     EBML_UINT, 0, offsetof(MatroskaTrack,flag_default), {.u=1} },
 411     { MATROSKA_ID_TRACKFLAGFORCED,      EBML_UINT, 0, offsetof(MatroskaTrack,flag_forced), {.u=0} },
 412     { MATROSKA_ID_TRACKVIDEO,           EBML_NEST, 0, offsetof(MatroskaTrack,video), {.n=matroska_track_video} },
 413     { MATROSKA_ID_TRACKAUDIO,           EBML_NEST, 0, offsetof(MatroskaTrack,audio), {.n=matroska_track_audio} },
 414     { MATROSKA_ID_TRACKOPERATION,       EBML_NEST, 0, offsetof(MatroskaTrack,operation), {.n=matroska_track_operation} },
 415     { MATROSKA_ID_TRACKCONTENTENCODINGS,EBML_NEST, 0, 0, {.n=matroska_track_encodings} },
 416     { MATROSKA_ID_TRACKMAXBLKADDID,     EBML_UINT, 0, offsetof(MatroskaTrack,max_block_additional_id) },
 417     { MATROSKA_ID_CODECDELAY,           EBML_UINT, 0, offsetof(MatroskaTrack,codec_delay) },
 418     { MATROSKA_ID_SEEKPREROLL,          EBML_UINT, 0, offsetof(MatroskaTrack,seek_preroll) },
 419     { MATROSKA_ID_TRACKFLAGENABLED,     EBML_NONE },
 420     { MATROSKA_ID_TRACKFLAGLACING,      EBML_NONE },
 421     { MATROSKA_ID_CODECNAME,            EBML_NONE },
 422     { MATROSKA_ID_CODECDECODEALL,       EBML_NONE },
 423     { MATROSKA_ID_CODECINFOURL,         EBML_NONE },
 424     { MATROSKA_ID_CODECDOWNLOADURL,     EBML_NONE },
 425     { MATROSKA_ID_TRACKMINCACHE,        EBML_NONE },
 426     { MATROSKA_ID_TRACKMAXCACHE,        EBML_NONE },
 427     { 0 }
 428 };
 429
 430 static EbmlSyntax matroska_tracks[] = {
 431     { MATROSKA_ID_TRACKENTRY,         EBML_NEST, sizeof(MatroskaTrack), offsetof(MatroskaDemuxContext,tracks), {.n=matroska_track} },
 432     { 0 }
 433 };
 434
 435 static EbmlSyntax matroska_attachment[] = {
 436     { MATROSKA_ID_FILEUID,            EBML_UINT, 0, offsetof(MatroskaAttachement,uid) },
 437     { MATROSKA_ID_FILENAME,           EBML_UTF8, 0, offsetof(MatroskaAttachement,filename) },
 438     { MATROSKA_ID_FILEMIMETYPE,       EBML_STR,  0, offsetof(MatroskaAttachement,mime) },
 439     { MATROSKA_ID_FILEDATA,           EBML_BIN,  0, offsetof(MatroskaAttachement,bin) },
 440     { MATROSKA_ID_FILEDESC,           EBML_NONE },
 441     { 0 }
 442 };
 443
 444 static EbmlSyntax matroska_attachments[] = {
 445     { MATROSKA_ID_ATTACHEDFILE,       EBML_NEST, sizeof(MatroskaAttachement), offsetof(MatroskaDemuxContext,attachments), {.n=matroska_attachment} },
 446     { 0 }
 447 };
 448
 449 static EbmlSyntax matroska_chapter_display[] = {
 450     { MATROSKA_ID_CHAPSTRING,         EBML_UTF8, 0, offsetof(MatroskaChapter,title) },
 451     { MATROSKA_ID_CHAPLANG,           EBML_NONE },
 452     { 0 }
 453 };
 454
 455 static EbmlSyntax matroska_chapter_entry[] = {
 456     { MATROSKA_ID_CHAPTERTIMESTART,   EBML_UINT, 0, offsetof(MatroskaChapter,start), {.u=AV_NOPTS_VALUE} },
 457     { MATROSKA_ID_CHAPTERTIMEEND,     EBML_UINT, 0, offsetof(MatroskaChapter,end), {.u=AV_NOPTS_VALUE} },
 458     { MATROSKA_ID_CHAPTERUID,         EBML_UINT, 0, offsetof(MatroskaChapter,uid) },
 459     { MATROSKA_ID_CHAPTERDISPLAY,     EBML_NEST, 0, 0, {.n=matroska_chapter_display} },
 460     { MATROSKA_ID_CHAPTERFLAGHIDDEN,  EBML_NONE },
 461     { MATROSKA_ID_CHAPTERFLAGENABLED, EBML_NONE },
 462     { MATROSKA_ID_CHAPTERPHYSEQUIV,   EBML_NONE },
 463     { MATROSKA_ID_CHAPTERATOM,        EBML_NONE },
 464     { 0 }
 465 };
 466
 467 static EbmlSyntax matroska_chapter[] = {
 468     { MATROSKA_ID_CHAPTERATOM,        EBML_NEST, sizeof(MatroskaChapter), offsetof(MatroskaDemuxContext,chapters), {.n=matroska_chapter_entry} },
 469     { MATROSKA_ID_EDITIONUID,         EBML_NONE },
 470     { MATROSKA_ID_EDITIONFLAGHIDDEN,  EBML_NONE },
 471     { MATROSKA_ID_EDITIONFLAGDEFAULT, EBML_NONE },
 472     { MATROSKA_ID_EDITIONFLAGORDERED, EBML_NONE },
 473     { 0 }
 474 };
 475
 476 static EbmlSyntax matroska_chapters[] = {
 477     { MATROSKA_ID_EDITIONENTRY,       EBML_NEST, 0, 0, {.n=matroska_chapter} },
 478     { 0 }
 479 };
 480
 481 static EbmlSyntax matroska_index_pos[] = {
 482     { MATROSKA_ID_CUETRACK,           EBML_UINT, 0, offsetof(MatroskaIndexPos,track) },
 483     { MATROSKA_ID_CUECLUSTERPOSITION, EBML_UINT, 0, offsetof(MatroskaIndexPos,pos)   },
 484     { MATROSKA_ID_CUERELATIVEPOSITION,EBML_NONE },
 485     { MATROSKA_ID_CUEDURATION,        EBML_NONE },
 486     { MATROSKA_ID_CUEBLOCKNUMBER,     EBML_NONE },
 487     { 0 }
 488 };
 489
 490 static EbmlSyntax matroska_index_entry[] = {
 491     { MATROSKA_ID_CUETIME,            EBML_UINT, 0, offsetof(MatroskaIndex,time) },
 492     { MATROSKA_ID_CUETRACKPOSITION,   EBML_NEST, sizeof(MatroskaIndexPos), offsetof(MatroskaIndex,pos), {.n=matroska_index_pos} },
 493     { 0 }
 494 };
 495
 496 static EbmlSyntax matroska_index[] = {
 497     { MATROSKA_ID_POINTENTRY,         EBML_NEST, sizeof(MatroskaIndex), offsetof(MatroskaDemuxContext,index), {.n=matroska_index_entry} },
 498     { 0 }
 499 };
 500
 501 static EbmlSyntax matroska_simpletag[] = {
 502     { MATROSKA_ID_TAGNAME,            EBML_UTF8, 0, offsetof(MatroskaTag,name) },
 503     { MATROSKA_ID_TAGSTRING,          EBML_UTF8, 0, offsetof(MatroskaTag,string) },
 504     { MATROSKA_ID_TAGLANG,            EBML_STR,  0, offsetof(MatroskaTag,lang), {.s="und"} },
 505     { MATROSKA_ID_TAGDEFAULT,         EBML_UINT, 0, offsetof(MatroskaTag,def) },
 506     { MATROSKA_ID_TAGDEFAULT_BUG,     EBML_UINT, 0, offsetof(MatroskaTag,def) },
 507     { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTag,sub), {.n=matroska_simpletag} },
 508     { 0 }
 509 };
 510
 511 static EbmlSyntax matroska_tagtargets[] = {
 512     { MATROSKA_ID_TAGTARGETS_TYPE,      EBML_STR,  0, offsetof(MatroskaTagTarget,type) },
 513     { MATROSKA_ID_TAGTARGETS_TYPEVALUE, EBML_UINT, 0, offsetof(MatroskaTagTarget,typevalue), {.u=50} },
 514     { MATROSKA_ID_TAGTARGETS_TRACKUID,  EBML_UINT, 0, offsetof(MatroskaTagTarget,trackuid) },
 515     { MATROSKA_ID_TAGTARGETS_CHAPTERUID,EBML_UINT, 0, offsetof(MatroskaTagTarget,chapteruid) },
 516     { MATROSKA_ID_TAGTARGETS_ATTACHUID, EBML_UINT, 0, offsetof(MatroskaTagTarget,attachuid) },
 517     { 0 }
 518 };
 519
 520 static EbmlSyntax matroska_tag[] = {
 521     { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTags,tag), {.n=matroska_simpletag} },
 522     { MATROSKA_ID_TAGTARGETS,         EBML_NEST, 0, offsetof(MatroskaTags,target), {.n=matroska_tagtargets} },
 523     { 0 }
 524 };
 525
 526 static EbmlSyntax matroska_tags[] = {
 527     { MATROSKA_ID_TAG,                EBML_NEST, sizeof(MatroskaTags), offsetof(MatroskaDemuxContext,tags), {.n=matroska_tag} },
 528     { 0 }
 529 };
 530
 531 static EbmlSyntax matroska_seekhead_entry[] = {
 532     { MATROSKA_ID_SEEKID,             EBML_UINT, 0, offsetof(MatroskaSeekhead,id) },
 533     { MATROSKA_ID_SEEKPOSITION,       EBML_UINT, 0, offsetof(MatroskaSeekhead,pos), {.u=-1} },
 534     { 0 }
 535 };
 536
 537 static EbmlSyntax matroska_seekhead[] = {
 538     { MATROSKA_ID_SEEKENTRY,          EBML_NEST, sizeof(MatroskaSeekhead), offsetof(MatroskaDemuxContext,seekhead), {.n=matroska_seekhead_entry} },
 539     { 0 }
 540 };
 541
 542 static EbmlSyntax matroska_segment[] = {
 543     { MATROSKA_ID_INFO,           EBML_NEST, 0, 0, {.n=matroska_info       } },
 544     { MATROSKA_ID_TRACKS,         EBML_NEST, 0, 0, {.n=matroska_tracks     } },
 545     { MATROSKA_ID_ATTACHMENTS,    EBML_NEST, 0, 0, {.n=matroska_attachments} },
 546     { MATROSKA_ID_CHAPTERS,       EBML_NEST, 0, 0, {.n=matroska_chapters   } },
 547     { MATROSKA_ID_CUES,           EBML_NEST, 0, 0, {.n=matroska_index      } },
 548     { MATROSKA_ID_TAGS,           EBML_NEST, 0, 0, {.n=matroska_tags       } },
 549     { MATROSKA_ID_SEEKHEAD,       EBML_NEST, 0, 0, {.n=matroska_seekhead   } },
 550     { MATROSKA_ID_CLUSTER,        EBML_STOP },
 551     { 0 }
 552 };
 553
 554 static EbmlSyntax matroska_segments[] = {
 555     { MATROSKA_ID_SEGMENT,        EBML_NEST, 0, 0, {.n=matroska_segment    } },
 556     { 0 }
 557 };
 558
 559 static EbmlSyntax matroska_blockmore[] = {
 560     { MATROSKA_ID_BLOCKADDID,      EBML_UINT, 0, offsetof(MatroskaBlock,additional_id) },
 561     { MATROSKA_ID_BLOCKADDITIONAL, EBML_BIN,  0, offsetof(MatroskaBlock,additional) },
 562     { 0 }
 563 };
 564
 565 static EbmlSyntax matroska_blockadditions[] = {
 566     { MATROSKA_ID_BLOCKMORE, EBML_NEST, 0, 0, {.n=matroska_blockmore} },
 567     { 0 }
 568 };
 569
 570 static EbmlSyntax matroska_blockgroup[] = {
 571     { MATROSKA_ID_BLOCK,          EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
 572     { MATROSKA_ID_BLOCKADDITIONS, EBML_NEST, 0, 0, {.n=matroska_blockadditions} },
 573     { MATROSKA_ID_SIMPLEBLOCK,    EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
 574     { MATROSKA_ID_BLOCKDURATION,  EBML_UINT, 0, offsetof(MatroskaBlock,duration) },
 575     { MATROSKA_ID_DISCARDPADDING, EBML_SINT, 0, offsetof(MatroskaBlock,discard_padding) },
 576     { MATROSKA_ID_BLOCKREFERENCE, EBML_SINT, 0, offsetof(MatroskaBlock,reference) },
 577     { MATROSKA_ID_CODECSTATE,     EBML_NONE },
 578     { 1,                          EBML_UINT, 0, offsetof(MatroskaBlock,non_simple), {.u=1} },
 579     { 0 }
 580 };
 581
 582 static EbmlSyntax matroska_cluster[] = {
 583     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
 584     { MATROSKA_ID_BLOCKGROUP,     EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 585     { MATROSKA_ID_SIMPLEBLOCK,    EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 586     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
 587     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
 588     { 0 }
 589 };
 590
 591 static EbmlSyntax matroska_clusters[] = {
 592     { MATROSKA_ID_CLUSTER,        EBML_NEST, 0, 0, {.n=matroska_cluster} },
 593     { MATROSKA_ID_INFO,           EBML_NONE },
 594     { MATROSKA_ID_CUES,           EBML_NONE },
 595     { MATROSKA_ID_TAGS,           EBML_NONE },
 596     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
 597     { 0 }
 598 };
 599
 600 static EbmlSyntax matroska_cluster_incremental_parsing[] = {
 601     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
 602     { MATROSKA_ID_BLOCKGROUP,     EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 603     { MATROSKA_ID_SIMPLEBLOCK,    EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 604     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
 605     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
 606     { MATROSKA_ID_INFO,           EBML_NONE },
 607     { MATROSKA_ID_CUES,           EBML_NONE },
 608     { MATROSKA_ID_TAGS,           EBML_NONE },
 609     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
 610     { MATROSKA_ID_CLUSTER,        EBML_STOP },
 611     { 0 }
 612 };
 613
 614 static EbmlSyntax matroska_cluster_incremental[] = {
 615     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
 616     { MATROSKA_ID_BLOCKGROUP,     EBML_STOP },
 617     { MATROSKA_ID_SIMPLEBLOCK,    EBML_STOP },
 618     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
 619     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
 620     { 0 }
 621 };
 622
 623 static EbmlSyntax matroska_clusters_incremental[] = {
 624     { MATROSKA_ID_CLUSTER,        EBML_NEST, 0, 0, {.n=matroska_cluster_incremental} },
 625     { MATROSKA_ID_INFO,           EBML_NONE },
 626     { MATROSKA_ID_CUES,           EBML_NONE },
 627     { MATROSKA_ID_TAGS,           EBML_NONE },
 628     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
 629     { 0 }
 630 };
 631
 632 static const char *const matroska_doctypes[] = { "matroska", "webm" };
 633
 634 static int matroska_resync(MatroskaDemuxContext *matroska, int64_t last_pos)
 635 {
 636     AVIOContext *pb = matroska->ctx->pb;
 637     uint32_t id;
 638     matroska->current_id = 0;
 639     matroska->num_levels = 0;
 640
 641     /* seek to next position to resync from */
 642     if (avio_seek(pb, last_pos + 1, SEEK_SET) < 0)
 643         goto eof;
 644
 645     id = avio_rb32(pb);
 646
 647     // try to find a toplevel element
 648     while (!url_feof(pb)) {
 649         if (id == MATROSKA_ID_INFO     || id == MATROSKA_ID_TRACKS      ||
 650             id == MATROSKA_ID_CUES     || id == MATROSKA_ID_TAGS        ||
 651             id == MATROSKA_ID_SEEKHEAD || id == MATROSKA_ID_ATTACHMENTS ||
 652             id == MATROSKA_ID_CLUSTER  || id == MATROSKA_ID_CHAPTERS) {
 653                 matroska->current_id = id;
 654                 return 0;
 655         }
 656         id = (id << 8) | avio_r8(pb);
 657     }
 658 eof:
 659     matroska->done = 1;
 660     return AVERROR_EOF;
 661 }
 662
 663 /*
 664  * Return: Whether we reached the end of a level in the hierarchy or not.
 665  */
 666 static int ebml_level_end(MatroskaDemuxContext *matroska)
 667 {
 668     AVIOContext *pb = matroska->ctx->pb;
 669     int64_t pos = avio_tell(pb);
 670
 671     if (matroska->num_levels > 0) {
 672         MatroskaLevel *level = &matroska->levels[matroska->num_levels - 1];
 673         if (pos - level->start >= level->length || matroska->current_id) {
 674             matroska->num_levels--;
 675             return 1;
 676         }
 677     }
 678     return 0;
 679 }
 680
 681 /*
 682  * Read: an "EBML number", which is defined as a variable-length
 683  * array of bytes. The first byte indicates the length by giving a
 684  * number of 0-bits followed by a one. The position of the first
 685  * "one" bit inside the first byte indicates the length of this
 686  * number.
 687  * Returns: number of bytes read, < 0 on error
 688  */
 689 static int ebml_read_num(MatroskaDemuxContext *matroska, AVIOContext *pb,
 690                          int max_size, uint64_t *number)
 691 {
 692     int read = 1, n = 1;
 693     uint64_t total = 0;
 694
 695     /* The first byte tells us the length in bytes - avio_r8() can normally
 696      * return 0, but since that's not a valid first ebmlID byte, we can
 697      * use it safely here to catch EOS. */
 698     if (!(total = avio_r8(pb))) {
 699         /* we might encounter EOS here */
 700         if (!url_feof(pb)) {
 701             int64_t pos = avio_tell(pb);
 702             av_log(matroska->ctx, AV_LOG_ERROR,
 703                    "Read error at pos. %"PRIu64" (0x%"PRIx64")\n",
 704                    pos, pos);
 705             return pb->error ? pb->error : AVERROR(EIO);
 706         }
 707         return AVERROR_EOF;
 708     }
 709
 710     /* get the length of the EBML number */
 711     read = 8 - ff_log2_tab[total];
 712     if (read > max_size) {
 713         int64_t pos = avio_tell(pb) - 1;
 714         av_log(matroska->ctx, AV_LOG_ERROR,
 715                "Invalid EBML number size tag 0x%02x at pos %"PRIu64" (0x%"PRIx64")\n",
 716                (uint8_t) total, pos, pos);
 717         return AVERROR_INVALIDDATA;
 718     }
 719
 720     /* read out length */
 721     total ^= 1 << ff_log2_tab[total];
 722     while (n++ < read)
 723         total = (total << 8) | avio_r8(pb);
 724
 725     *number = total;
 726
 727     return read;
 728 }
 729
 730 /**
 731  * Read a EBML length value.
 732  * This needs special handling for the "unknown length" case which has multiple
 733  * encodings.
 734  */
 735 static int ebml_read_length(MatroskaDemuxContext *matroska, AVIOContext *pb,
 736                             uint64_t *number)
 737 {
 738     int res = ebml_read_num(matroska, pb, 8, number);
 739     if (res > 0 && *number + 1 == 1ULL << (7 * res))
 740         *number = 0xffffffffffffffULL;
 741     return res;
 742 }
 743
 744 /*
 745  * Read the next element as an unsigned int.
 746  * 0 is success, < 0 is failure.
 747  */
 748 static int ebml_read_uint(AVIOContext *pb, int size, uint64_t *num)
 749 {
 750     int n = 0;
 751
 752     if (size > 8)
 753         return AVERROR_INVALIDDATA;
 754
 755     /* big-endian ordering; build up number */
 756     *num = 0;
 757     while (n++ < size)
 758         *num = (*num << 8) | avio_r8(pb);
 759
 760     return 0;
 761 }
 762
 763 /*
 764  * Read the next element as a signed int.
 765  * 0 is success, < 0 is failure.
 766  */
 767 static int ebml_read_sint(AVIOContext *pb, int size, int64_t *num)
 768 {
 769     int n = 1;
 770
 771     if (size > 8)
 772         return AVERROR_INVALIDDATA;
 773
 774     if (size == 0) {
 775         *num = 0;
 776     } else {
 777         *num = sign_extend(avio_r8(pb), 8);
 778
 779         /* big-endian ordering; build up number */
 780         while (n++ < size)
 781             *num = (*num << 8) | avio_r8(pb);
 782     }
 783
 784     return 0;
 785 }
 786
 787 /*
 788  * Read the next element as a float.
 789  * 0 is success, < 0 is failure.
 790  */
 791 static int ebml_read_float(AVIOContext *pb, int size, double *num)
 792 {
 793     if (size == 0) {
 794         *num = 0;
 795     } else if (size == 4) {
 796         *num = av_int2float(avio_rb32(pb));
 797     } else if (size == 8){
 798         *num = av_int2double(avio_rb64(pb));
 799     } else
 800         return AVERROR_INVALIDDATA;
 801
 802     return 0;
 803 }
 804
 805 /*
 806  * Read the next element as an ASCII string.
 807  * 0 is success, < 0 is failure.
 808  */
 809 static int ebml_read_ascii(AVIOContext *pb, int size, char **str)
 810 {
 811     char *res;
 812
 813     /* EBML strings are usually not 0-terminated, so we allocate one
 814      * byte more, read the string and NULL-terminate it ourselves. */
 815     if (!(res = av_malloc(size + 1)))
 816         return AVERROR(ENOMEM);
 817     if (avio_read(pb, (uint8_t *) res, size) != size) {
 818         av_free(res);
 819         return AVERROR(EIO);
 820     }
 821     (res)[size] = '\0';
 822     av_free(*str);
 823     *str = res;
 824
 825     return 0;
 826 }
 827
 828 /*
 829  * Read the next element as binary data.
 830  * 0 is success, < 0 is failure.
 831  */
 832 static int ebml_read_binary(AVIOContext *pb, int length, EbmlBin *bin)
 833 {
 834     av_fast_padded_malloc(&bin->data, &bin->size, length);
 835     if (!bin->data)
 836         return AVERROR(ENOMEM);
 837
 838     bin->size = length;
 839     bin->pos  = avio_tell(pb);
 840     if (avio_read(pb, bin->data, length) != length) {
 841         av_freep(&bin->data);
 842         bin->size = 0;
 843         return AVERROR(EIO);
 844     }
 845
 846     return 0;
 847 }
 848
 849 /*
 850  * Read the next element, but only the header. The contents
 851  * are supposed to be sub-elements which can be read separately.
 852  * 0 is success, < 0 is failure.
 853  */
 854 static int ebml_read_master(MatroskaDemuxContext *matroska, uint64_t length)
 855 {
 856     AVIOContext *pb = matroska->ctx->pb;
 857     MatroskaLevel *level;
 858
 859     if (matroska->num_levels >= EBML_MAX_DEPTH) {
 860         av_log(matroska->ctx, AV_LOG_ERROR,
 861                "File moves beyond max. allowed depth (%d)\n", EBML_MAX_DEPTH);
 862         return AVERROR(ENOSYS);
 863     }
 864
 865     level = &matroska->levels[matroska->num_levels++];
 866     level->start = avio_tell(pb);
 867     level->length = length;
 868
 869     return 0;
 870 }
 871
 872 /*
 873  * Read signed/unsigned "EBML" numbers.
 874  * Return: number of bytes processed, < 0 on error
 875  */
 876 static int matroska_ebmlnum_uint(MatroskaDemuxContext *matroska,
 877                                  uint8_t *data, uint32_t size, uint64_t *num)
 878 {
 879     AVIOContext pb;
 880     ffio_init_context(&pb, data, size, 0, NULL, NULL, NULL, NULL);
 881     return ebml_read_num(matroska, &pb, FFMIN(size, 8), num);
 882 }
 883
 884 /*
 885  * Same as above, but signed.
 886  */
 887 static int matroska_ebmlnum_sint(MatroskaDemuxContext *matroska,
 888                                  uint8_t *data, uint32_t size, int64_t *num)
 889 {
 890     uint64_t unum;
 891     int res;
 892
 893     /* read as unsigned number first */
 894     if ((res = matroska_ebmlnum_uint(matroska, data, size, &unum)) < 0)
 895         return res;
 896
 897     /* make signed (weird way) */
 898     *num = unum - ((1LL << (7*res - 1)) - 1);
 899
 900     return res;
 901 }
 902
 903 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
 904                            EbmlSyntax *syntax, void *data);
 905
 906 static int ebml_parse_id(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 907                          uint32_t id, void *data)
 908 {
 909     int i;
 910     for (i=0; syntax[i].id; i++)
 911         if (id == syntax[i].id)
 912             break;
 913     if (!syntax[i].id && id == MATROSKA_ID_CLUSTER &&
 914         matroska->num_levels > 0 &&
 915         matroska->levels[matroska->num_levels-1].length == 0xffffffffffffff)
 916         return 0;  // we reached the end of an unknown size cluster
 917     if (!syntax[i].id && id != EBML_ID_VOID && id != EBML_ID_CRC32) {
 918         av_log(matroska->ctx, AV_LOG_INFO, "Unknown entry 0x%X\n", id);
 919         if (matroska->ctx->error_recognition & AV_EF_EXPLODE)
 920             return AVERROR_INVALIDDATA;
 921     }
 922     return ebml_parse_elem(matroska, &syntax[i], data);
 923 }
 924
 925 static int ebml_parse(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 926                       void *data)
 927 {
 928     if (!matroska->current_id) {
 929         uint64_t id;
 930         int res = ebml_read_num(matroska, matroska->ctx->pb, 4, &id);
 931         if (res < 0)
 932             return res;
 933         matroska->current_id = id | 1 << 7*res;
 934     }
 935     return ebml_parse_id(matroska, syntax, matroska->current_id, data);
 936 }
 937
 938 static int ebml_parse_nest(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 939                            void *data)
 940 {
 941     int i, res = 0;
 942
 943     for (i=0; syntax[i].id; i++)
 944         switch (syntax[i].type) {
 945         case EBML_UINT:
 946             *(uint64_t *)((char *)data+syntax[i].data_offset) = syntax[i].def.u;
 947             break;
 948         case EBML_FLOAT:
 949             *(double   *)((char *)data+syntax[i].data_offset) = syntax[i].def.f;
 950             break;
 951         case EBML_STR:
 952         case EBML_UTF8:
 953             // the default may be NULL
 954             if (syntax[i].def.s) {
 955                 uint8_t **dst = (uint8_t**)((uint8_t*)data + syntax[i].data_offset);
 956                 *dst = av_strdup(syntax[i].def.s);
 957                 if (!*dst)
 958                     return AVERROR(ENOMEM);
 959             }
 960             break;
 961         }
 962
 963     while (!res && !ebml_level_end(matroska))
 964         res = ebml_parse(matroska, syntax, data);
 965
 966     return res;
 967 }
 968
 969 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
 970                            EbmlSyntax *syntax, void *data)
 971 {
 972     static const uint64_t max_lengths[EBML_TYPE_COUNT] = {
 973         [EBML_UINT]  = 8,
 974         [EBML_FLOAT] = 8,
 975         // max. 16 MB for strings
 976         [EBML_STR]   = 0x1000000,
 977         [EBML_UTF8]  = 0x1000000,
 978         // max. 256 MB for binary data
 979         [EBML_BIN]   = 0x10000000,
 980         // no limits for anything else
 981     };
 982     AVIOContext *pb = matroska->ctx->pb;
 983     uint32_t id = syntax->id;
 984     uint64_t length;
 985     int res;
 986     void *newelem;
 987
 988     data = (char *)data + syntax->data_offset;
 989     if (syntax->list_elem_size) {
 990         EbmlList *list = data;
 991         newelem = av_realloc_array(list->elem, list->nb_elem+1, syntax->list_elem_size);
 992         if (!newelem)
 993             return AVERROR(ENOMEM);
 994         list->elem = newelem;
 995         data = (char*)list->elem + list->nb_elem*syntax->list_elem_size;
 996         memset(data, 0, syntax->list_elem_size);
 997         list->nb_elem++;
 998     }
 999
1000     if (syntax->type != EBML_PASS && syntax->type != EBML_STOP) {
1001         matroska->current_id = 0;
1002         if ((res = ebml_read_length(matroska, pb, &length)) < 0)
1003             return res;
1004         if (max_lengths[syntax->type] && length > max_lengths[syntax->type]) {
1005             av_log(matroska->ctx, AV_LOG_ERROR,
1006                    "Invalid length 0x%"PRIx64" > 0x%"PRIx64" for syntax element %i\n",
1007                    length, max_lengths[syntax->type], syntax->type);
1008             return AVERROR_INVALIDDATA;
1009         }
1010     }
1011
1012     switch (syntax->type) {
1013     case EBML_UINT:  res = ebml_read_uint  (pb, length, data);  break;
1014     case EBML_SINT:  res = ebml_read_sint  (pb, length, data);  break;
1015     case EBML_FLOAT: res = ebml_read_float (pb, length, data);  break;
1016     case EBML_STR:
1017     case EBML_UTF8:  res = ebml_read_ascii (pb, length, data);  break;
1018     case EBML_BIN:   res = ebml_read_binary(pb, length, data);  break;
1019     case EBML_NEST:  if ((res=ebml_read_master(matroska, length)) < 0)
1020                          return res;
1021                      if (id == MATROSKA_ID_SEGMENT)
1022                          matroska->segment_start = avio_tell(matroska->ctx->pb);
1023                      return ebml_parse_nest(matroska, syntax->def.n, data);
1024     case EBML_PASS:  return ebml_parse_id(matroska, syntax->def.n, id, data);
1025     case EBML_STOP:  return 1;
1026     default:
1027         if(ffio_limit(pb, length) != length)
1028             return AVERROR(EIO);
1029         return avio_skip(pb,length)<0 ? AVERROR(EIO) : 0;
1030     }
1031     if (res == AVERROR_INVALIDDATA)
1032         av_log(matroska->ctx, AV_LOG_ERROR, "Invalid element\n");
1033     else if (res == AVERROR(EIO))
1034         av_log(matroska->ctx, AV_LOG_ERROR, "Read error\n");
1035     return res;
1036 }
1037
1038 static void ebml_free(EbmlSyntax *syntax, void *data)
1039 {
1040     int i, j;
1041     for (i=0; syntax[i].id; i++) {
1042         void *data_off = (char *)data + syntax[i].data_offset;
1043         switch (syntax[i].type) {
1044         case EBML_STR:
1045         case EBML_UTF8:  av_freep(data_off);                      break;
1046         case EBML_BIN:   av_freep(&((EbmlBin *)data_off)->data);  break;
1047         case EBML_NEST:
1048             if (syntax[i].list_elem_size) {
1049                 EbmlList *list = data_off;
1050                 char *ptr = list->elem;
1051                 for (j=0; j<list->nb_elem; j++, ptr+=syntax[i].list_elem_size)
1052                     ebml_free(syntax[i].def.n, ptr);
1053                 av_free(list->elem);
1054             } else
1055                 ebml_free(syntax[i].def.n, data_off);
1056         default:  break;
1057         }
1058     }
1059 }
1060
1061
1062 /*
1063  * Autodetecting...
1064  */
1065 static int matroska_probe(AVProbeData *p)
1066 {
1067     uint64_t total = 0;
1068     int len_mask = 0x80, size = 1, n = 1, i;
1069
1070     /* EBML header? */
1071     if (AV_RB32(p->buf) != EBML_ID_HEADER)
1072         return 0;
1073
1074     /* length of header */
1075     total = p->buf[4];
1076     while (size <= 8 && !(total & len_mask)) {
1077         size++;
1078         len_mask >>= 1;
1079     }
1080     if (size > 8)
1081       return 0;
1082     total &= (len_mask - 1);
1083     while (n < size)
1084         total = (total << 8) | p->buf[4 + n++];
1085
1086     /* Does the probe data contain the whole header? */
1087     if (p->buf_size < 4 + size + total)
1088       return 0;
1089
1090     /* The header should contain a known document type. For now,
1091      * we don't parse the whole header but simply check for the
1092      * availability of that array of characters inside the header.
1093      * Not fully fool-proof, but good enough. */
1094     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++) {
1095         int probelen = strlen(matroska_doctypes[i]);
1096         if (total < probelen)
1097             continue;
1098         for (n = 4+size; n <= 4+size+total-probelen; n++)
1099             if (!memcmp(p->buf+n, matroska_doctypes[i], probelen))
1100                 return AVPROBE_SCORE_MAX;
1101     }
1102
1103     // probably valid EBML header but no recognized doctype
1104     return AVPROBE_SCORE_EXTENSION;
1105 }
1106
1107 static MatroskaTrack *matroska_find_track_by_num(MatroskaDemuxContext *matroska,
1108                                                  int num)
1109 {
1110     MatroskaTrack *tracks = matroska->tracks.elem;
1111     int i;
1112
1113     for (i=0; i < matroska->tracks.nb_elem; i++)
1114         if (tracks[i].num == num)
1115             return &tracks[i];
1116
1117     av_log(matroska->ctx, AV_LOG_ERROR, "Invalid track number %d\n", num);
1118     return NULL;
1119 }
1120
1121 static int matroska_decode_buffer(uint8_t** buf, int* buf_size,
1122                                   MatroskaTrack *track)
1123 {
1124     MatroskaTrackEncoding *encodings = track->encodings.elem;
1125     uint8_t* data = *buf;
1126     int isize = *buf_size;
1127     uint8_t* pkt_data = NULL;
1128     uint8_t av_unused *newpktdata;
1129     int pkt_size = isize;
1130     int result = 0;
1131     int olen;
1132
1133     if (pkt_size >= 10000000U)
1134         return AVERROR_INVALIDDATA;
1135
1136     switch (encodings[0].compression.algo) {
1137     case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP: {
1138         int header_size = encodings[0].compression.settings.size;
1139         uint8_t *header = encodings[0].compression.settings.data;
1140
1141         if (header_size && !header) {
1142             av_log(NULL, AV_LOG_ERROR, "Compression size but no data in headerstrip\n");
1143             return -1;
1144         }
1145
1146         if (!header_size)
1147             return 0;
1148
1149         pkt_size = isize + header_size;
1150         pkt_data = av_malloc(pkt_size);
1151         if (!pkt_data)
1152             return AVERROR(ENOMEM);
1153
1154         memcpy(pkt_data, header, header_size);
1155         memcpy(pkt_data + header_size, data, isize);
1156         break;
1157     }
1158 #if CONFIG_LZO
1159     case MATROSKA_TRACK_ENCODING_COMP_LZO:
1160         do {
1161             olen = pkt_size *= 3;
1162             newpktdata = av_realloc(pkt_data, pkt_size + AV_LZO_OUTPUT_PADDING);
1163             if (!newpktdata) {
1164                 result = AVERROR(ENOMEM);
1165                 goto failed;
1166             }
1167             pkt_data = newpktdata;
1168             result = av_lzo1x_decode(pkt_data, &olen, data, &isize);
1169         } while (result==AV_LZO_OUTPUT_FULL && pkt_size<10000000);
1170         if (result) {
1171             result = AVERROR_INVALIDDATA;
1172             goto failed;
1173         }
1174         pkt_size -= olen;
1175         break;
1176 #endif
1177 #if CONFIG_ZLIB
1178     case MATROSKA_TRACK_ENCODING_COMP_ZLIB: {
1179         z_stream zstream = {0};
1180         if (inflateInit(&zstream) != Z_OK)
1181             return -1;
1182         zstream.next_in = data;
1183         zstream.avail_in = isize;
1184         do {
1185             pkt_size *= 3;
1186             newpktdata = av_realloc(pkt_data, pkt_size);
1187             if (!newpktdata) {
1188                 inflateEnd(&zstream);
1189                 goto failed;
1190             }
1191             pkt_data = newpktdata;
1192             zstream.avail_out = pkt_size - zstream.total_out;
1193             zstream.next_out = pkt_data + zstream.total_out;
1194             if (pkt_data) {
1195                 result = inflate(&zstream, Z_NO_FLUSH);
1196             } else
1197                 result = Z_MEM_ERROR;
1198         } while (result==Z_OK && pkt_size<10000000);
1199         pkt_size = zstream.total_out;
1200         inflateEnd(&zstream);
1201         if (result != Z_STREAM_END) {
1202             if (result == Z_MEM_ERROR)
1203                 result = AVERROR(ENOMEM);
1204             else
1205                 result = AVERROR_INVALIDDATA;
1206             goto failed;
1207         }
1208         break;
1209     }
1210 #endif
1211 #if CONFIG_BZLIB
1212     case MATROSKA_TRACK_ENCODING_COMP_BZLIB: {
1213         bz_stream bzstream = {0};
1214         if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
1215             return -1;
1216         bzstream.next_in = data;
1217         bzstream.avail_in = isize;
1218         do {
1219             pkt_size *= 3;
1220             newpktdata = av_realloc(pkt_data, pkt_size);
1221             if (!newpktdata) {
1222                 BZ2_bzDecompressEnd(&bzstream);
1223                 goto failed;
1224             }
1225             pkt_data = newpktdata;
1226             bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
1227             bzstream.next_out = pkt_data + bzstream.total_out_lo32;
1228             if (pkt_data) {
1229                 result = BZ2_bzDecompress(&bzstream);
1230             } else
1231                 result = BZ_MEM_ERROR;
1232         } while (result==BZ_OK && pkt_size<10000000);
1233         pkt_size = bzstream.total_out_lo32;
1234         BZ2_bzDecompressEnd(&bzstream);
1235         if (result != BZ_STREAM_END) {
1236             if (result == BZ_MEM_ERROR)
1237                 result = AVERROR(ENOMEM);
1238             else
1239                 result = AVERROR_INVALIDDATA;
1240             goto failed;
1241         }
1242         break;
1243     }
1244 #endif
1245     default:
1246         return AVERROR_INVALIDDATA;
1247     }
1248
1249     *buf = pkt_data;
1250     *buf_size = pkt_size;
1251     return 0;
1252  failed:
1253     av_free(pkt_data);
1254     return result;
1255 }
1256
1257 #if FF_API_ASS_SSA
1258 static void matroska_fix_ass_packet(MatroskaDemuxContext *matroska,
1259                                     AVPacket *pkt, uint64_t display_duration)
1260 {
1261     AVBufferRef *line;
1262     char *layer, *ptr = pkt->data, *end = ptr+pkt->size;
1263     for (; *ptr!=',' && ptr<end-1; ptr++);
1264     if (*ptr == ',')
1265         ptr++;
1266     layer = ptr;
1267     for (; *ptr!=',' && ptr<end-1; ptr++);
1268     if (*ptr == ',') {
1269         int64_t end_pts = pkt->pts + display_duration;
1270         int sc = matroska->time_scale * pkt->pts / 10000000;
1271         int ec = matroska->time_scale * end_pts  / 10000000;
1272         int sh, sm, ss, eh, em, es, len;
1273         sh = sc/360000;  sc -= 360000*sh;
1274         sm = sc/  6000;  sc -=   6000*sm;
1275         ss = sc/   100;  sc -=    100*ss;
1276         eh = ec/360000;  ec -= 360000*eh;
1277         em = ec/  6000;  ec -=   6000*em;
1278         es = ec/   100;  ec -=    100*es;
1279         *ptr++ = '\0';
1280         len = 50 + end-ptr + FF_INPUT_BUFFER_PADDING_SIZE;
1281         if (!(line = av_buffer_alloc(len)))
1282             return;
1283         snprintf(line->data, len,"Dialogue: %s,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s\r\n",
1284                  layer, sh, sm, ss, sc, eh, em, es, ec, ptr);
1285         av_buffer_unref(&pkt->buf);
1286         pkt->buf  = line;
1287         pkt->data = line->data;
1288         pkt->size = strlen(line->data);
1289     }
1290 }
1291
1292 static int matroska_merge_packets(AVPacket *out, AVPacket *in)
1293 {
1294     int ret = av_grow_packet(out, in->size);
1295     if (ret < 0)
1296         return ret;
1297
1298     memcpy(out->data + out->size - in->size, in->data, in->size);
1299
1300     av_free_packet(in);
1301     av_free(in);
1302     return 0;
1303 }
1304 #endif
1305
1306 static void matroska_convert_tag(AVFormatContext *s, EbmlList *list,
1307                                  AVDictionary **metadata, char *prefix)
1308 {
1309     MatroskaTag *tags = list->elem;
1310     char key[1024];
1311     int i;
1312
1313     for (i=0; i < list->nb_elem; i++) {
1314         const char *lang = tags[i].lang && strcmp(tags[i].lang, "und") ?
1315                            tags[i].lang : NULL;
1316
1317         if (!tags[i].name) {
1318             av_log(s, AV_LOG_WARNING, "Skipping invalid tag with no TagName.\n");
1319             continue;
1320         }
1321         if (prefix)  snprintf(key, sizeof(key), "%s/%s", prefix, tags[i].name);
1322         else         av_strlcpy(key, tags[i].name, sizeof(key));
1323         if (tags[i].def || !lang) {
1324         av_dict_set(metadata, key, tags[i].string, 0);
1325         if (tags[i].sub.nb_elem)
1326             matroska_convert_tag(s, &tags[i].sub, metadata, key);
1327         }
1328         if (lang) {
1329             av_strlcat(key, "-", sizeof(key));
1330             av_strlcat(key, lang, sizeof(key));
1331             av_dict_set(metadata, key, tags[i].string, 0);
1332             if (tags[i].sub.nb_elem)
1333                 matroska_convert_tag(s, &tags[i].sub, metadata, key);
1334         }
1335     }
1336     ff_metadata_conv(metadata, NULL, ff_mkv_metadata_conv);
1337 }
1338
1339 static void matroska_convert_tags(AVFormatContext *s)
1340 {
1341     MatroskaDemuxContext *matroska = s->priv_data;
1342     MatroskaTags *tags = matroska->tags.elem;
1343     int i, j;
1344
1345     for (i=0; i < matroska->tags.nb_elem; i++) {
1346         if (tags[i].target.attachuid) {
1347             MatroskaAttachement *attachment = matroska->attachments.elem;
1348             for (j=0; j<matroska->attachments.nb_elem; j++)
1349                 if (attachment[j].uid == tags[i].target.attachuid
1350                     && attachment[j].stream)
1351                     matroska_convert_tag(s, &tags[i].tag,
1352                                          &attachment[j].stream->metadata, NULL);
1353         } else if (tags[i].target.chapteruid) {
1354             MatroskaChapter *chapter = matroska->chapters.elem;
1355             for (j=0; j<matroska->chapters.nb_elem; j++)
1356                 if (chapter[j].uid == tags[i].target.chapteruid
1357                     && chapter[j].chapter)
1358                     matroska_convert_tag(s, &tags[i].tag,
1359                                          &chapter[j].chapter->metadata, NULL);
1360         } else if (tags[i].target.trackuid) {
1361             MatroskaTrack *track = matroska->tracks.elem;
1362             for (j=0; j<matroska->tracks.nb_elem; j++)
1363                 if (track[j].uid == tags[i].target.trackuid && track[j].stream)
1364                     matroska_convert_tag(s, &tags[i].tag,
1365                                          &track[j].stream->metadata, NULL);
1366         } else {
1367             matroska_convert_tag(s, &tags[i].tag, &s->metadata,
1368                                  tags[i].target.type);
1369         }
1370     }
1371 }
1372
1373 static int matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska, int idx)
1374 {
1375     EbmlList *seekhead_list = &matroska->seekhead;
1376     MatroskaSeekhead *seekhead = seekhead_list->elem;
1377     uint32_t level_up = matroska->level_up;
1378     int64_t before_pos = avio_tell(matroska->ctx->pb);
1379     uint32_t saved_id = matroska->current_id;
1380     MatroskaLevel level;
1381     int64_t offset;
1382     int ret = 0;
1383
1384     if (idx >= seekhead_list->nb_elem
1385             || seekhead[idx].id == MATROSKA_ID_SEEKHEAD
1386             || seekhead[idx].id == MATROSKA_ID_CLUSTER)
1387         return 0;
1388
1389     /* seek */
1390     offset = seekhead[idx].pos + matroska->segment_start;
1391     if (avio_seek(matroska->ctx->pb, offset, SEEK_SET) == offset) {
1392         /* We don't want to lose our seekhead level, so we add
1393          * a dummy. This is a crude hack. */
1394         if (matroska->num_levels == EBML_MAX_DEPTH) {
1395             av_log(matroska->ctx, AV_LOG_INFO,
1396                    "Max EBML element depth (%d) reached, "
1397                    "cannot parse further.\n", EBML_MAX_DEPTH);
1398             ret = AVERROR_INVALIDDATA;
1399         } else {
1400             level.start = 0;
1401             level.length = (uint64_t)-1;
1402             matroska->levels[matroska->num_levels] = level;
1403             matroska->num_levels++;
1404             matroska->current_id = 0;
1405
1406             ret = ebml_parse(matroska, matroska_segment, matroska);
1407
1408             /* remove dummy level */
1409             while (matroska->num_levels) {
1410                 uint64_t length = matroska->levels[--matroska->num_levels].length;
1411                 if (length == (uint64_t)-1)
1412                     break;
1413             }
1414         }
1415     }
1416     /* seek back */
1417     avio_seek(matroska->ctx->pb, before_pos, SEEK_SET);
1418     matroska->level_up = level_up;
1419     matroska->current_id = saved_id;
1420
1421     return ret;
1422 }
1423
1424 static void matroska_execute_seekhead(MatroskaDemuxContext *matroska)
1425 {
1426     EbmlList *seekhead_list = &matroska->seekhead;
1427     int64_t before_pos = avio_tell(matroska->ctx->pb);
1428     int i;
1429
1430     // we should not do any seeking in the streaming case
1431     if (!matroska->ctx->pb->seekable ||
1432         (matroska->ctx->flags & AVFMT_FLAG_IGNIDX))
1433         return;
1434
1435     for (i = 0; i < seekhead_list->nb_elem; i++) {
1436         MatroskaSeekhead *seekhead = seekhead_list->elem;
1437         if (seekhead[i].pos <= before_pos)
1438             continue;
1439
1440         // defer cues parsing until we actually need cue data.
1441         if (seekhead[i].id == MATROSKA_ID_CUES) {
1442             matroska->cues_parsing_deferred = 1;
1443             continue;
1444         }
1445
1446         if (matroska_parse_seekhead_entry(matroska, i) < 0) {
1447             // mark index as broken
1448             matroska->cues_parsing_deferred = -1;
1449             break;
1450         }
1451     }
1452 }
1453
1454 static void matroska_add_index_entries(MatroskaDemuxContext *matroska) {
1455     EbmlList *index_list;
1456     MatroskaIndex *index;
1457     int index_scale = 1;
1458     int i, j;
1459
1460     index_list = &matroska->index;
1461     index = index_list->elem;
1462     if (index_list->nb_elem
1463         && index[0].time > 1E14/matroska->time_scale) {
1464         av_log(matroska->ctx, AV_LOG_WARNING, "Working around broken index.\n");
1465         index_scale = matroska->time_scale;
1466     }
1467     for (i = 0; i < index_list->nb_elem; i++) {
1468         EbmlList *pos_list = &index[i].pos;
1469         MatroskaIndexPos *pos = pos_list->elem;
1470         for (j = 0; j < pos_list->nb_elem; j++) {
1471             MatroskaTrack *track = matroska_find_track_by_num(matroska, pos[j].track);
1472             if (track && track->stream)
1473                 av_add_index_entry(track->stream,
1474                                    pos[j].pos + matroska->segment_start,
1475                                    index[i].time/index_scale, 0, 0,
1476                                    AVINDEX_KEYFRAME);
1477         }
1478     }
1479 }
1480
1481 static void matroska_parse_cues(MatroskaDemuxContext *matroska) {
1482     EbmlList *seekhead_list = &matroska->seekhead;
1483     MatroskaSeekhead *seekhead = seekhead_list->elem;
1484     int i;
1485
1486     for (i = 0; i < seekhead_list->nb_elem; i++)
1487         if (seekhead[i].id == MATROSKA_ID_CUES)
1488             break;
1489     av_assert1(i <= seekhead_list->nb_elem);
1490
1491     if (matroska_parse_seekhead_entry(matroska, i) < 0)
1492        matroska->cues_parsing_deferred = -1;
1493     matroska_add_index_entries(matroska);
1494 }
1495
1496 static int matroska_aac_profile(char *codec_id)
1497 {
1498     static const char * const aac_profiles[] = { "MAIN", "LC", "SSR" };
1499     int profile;
1500
1501     for (profile=0; profile<FF_ARRAY_ELEMS(aac_profiles); profile++)
1502         if (strstr(codec_id, aac_profiles[profile]))
1503             break;
1504     return profile + 1;
1505 }
1506
1507 static int matroska_aac_sri(int samplerate)
1508 {
1509     int sri;
1510
1511     for (sri=0; sri<FF_ARRAY_ELEMS(avpriv_mpeg4audio_sample_rates); sri++)
1512         if (avpriv_mpeg4audio_sample_rates[sri] == samplerate)
1513             break;
1514     return sri;
1515 }
1516
1517 static void matroska_metadata_creation_time(AVDictionary **metadata, int64_t date_utc)
1518 {
1519     char buffer[32];
1520     /* Convert to seconds and adjust by number of seconds between 2001-01-01 and Epoch */
1521     time_t creation_time = date_utc / 1000000000 + 978307200;
1522     struct tm *ptm = gmtime(&creation_time);
1523     if (!ptm) return;
1524     strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", ptm);
1525     av_dict_set(metadata, "creation_time", buffer, 0);
1526 }
1527
1528 static int matroska_read_header(AVFormatContext *s)
1529 {
1530     MatroskaDemuxContext *matroska = s->priv_data;
1531     EbmlList *attachements_list = &matroska->attachments;
1532     MatroskaAttachement *attachements;
1533     EbmlList *chapters_list = &matroska->chapters;
1534     MatroskaChapter *chapters;
1535     MatroskaTrack *tracks;
1536     uint64_t max_start = 0;
1537     int64_t pos;
1538     Ebml ebml = { 0 };
1539     AVStream *st;
1540     int i, j, k, res;
1541
1542     matroska->ctx = s;
1543
1544     /* First read the EBML header. */
1545     if (ebml_parse(matroska, ebml_syntax, &ebml)
1546         || ebml.version > EBML_VERSION       || ebml.max_size > sizeof(uint64_t)
1547         || ebml.id_length > sizeof(uint32_t) || ebml.doctype_version > 3 || !ebml.doctype) {
1548         av_log(matroska->ctx, AV_LOG_ERROR,
1549                "EBML header using unsupported features\n"
1550                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
1551                ebml.version, ebml.doctype, ebml.doctype_version);
1552         ebml_free(ebml_syntax, &ebml);
1553         return AVERROR_PATCHWELCOME;
1554     } else if (ebml.doctype_version == 3) {
1555         av_log(matroska->ctx, AV_LOG_WARNING,
1556                "EBML header using unsupported features\n"
1557                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
1558                ebml.version, ebml.doctype, ebml.doctype_version);
1559     }
1560     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++)
1561         if (!strcmp(ebml.doctype, matroska_doctypes[i]))
1562             break;
1563     if (i >= FF_ARRAY_ELEMS(matroska_doctypes)) {
1564         av_log(s, AV_LOG_WARNING, "Unknown EBML doctype '%s'\n", ebml.doctype);
1565         if (matroska->ctx->error_recognition & AV_EF_EXPLODE) {
1566             ebml_free(ebml_syntax, &ebml);
1567             return AVERROR_INVALIDDATA;
1568         }
1569     }
1570     ebml_free(ebml_syntax, &ebml);
1571
1572     /* The next thing is a segment. */
1573     pos = avio_tell(matroska->ctx->pb);
1574     res = ebml_parse(matroska, matroska_segments, matroska);
1575     // try resyncing until we find a EBML_STOP type element.
1576     while (res != 1) {
1577         res = matroska_resync(matroska, pos);
1578         if (res < 0)
1579             return res;
1580         pos = avio_tell(matroska->ctx->pb);
1581         res = ebml_parse(matroska, matroska_segment, matroska);
1582     }
1583     matroska_execute_seekhead(matroska);
1584
1585     if (!matroska->time_scale)
1586         matroska->time_scale = 1000000;
1587     if (matroska->duration)
1588         matroska->ctx->duration = matroska->duration * matroska->time_scale
1589                                   * 1000 / AV_TIME_BASE;
1590     av_dict_set(&s->metadata, "title", matroska->title, 0);
1591     av_dict_set(&s->metadata, "encoder", matroska->muxingapp, 0);
1592
1593     if (matroska->date_utc.size == 8)
1594         matroska_metadata_creation_time(&s->metadata, AV_RB64(matroska->date_utc.data));
1595
1596     tracks = matroska->tracks.elem;
1597     for (i=0; i < matroska->tracks.nb_elem; i++) {
1598         MatroskaTrack *track = &tracks[i];
1599         enum AVCodecID codec_id = AV_CODEC_ID_NONE;
1600         EbmlList *encodings_list = &track->encodings;
1601         MatroskaTrackEncoding *encodings = encodings_list->elem;
1602         uint8_t *extradata = NULL;
1603         int extradata_size = 0;
1604         int extradata_offset = 0;
1605         uint32_t fourcc = 0;
1606         AVIOContext b;
1607         char* key_id_base64 = NULL;
1608
1609         /* Apply some sanity checks. */
1610         if (track->type != MATROSKA_TRACK_TYPE_VIDEO &&
1611             track->type != MATROSKA_TRACK_TYPE_AUDIO &&
1612             track->type != MATROSKA_TRACK_TYPE_SUBTITLE &&
1613             track->type != MATROSKA_TRACK_TYPE_METADATA) {
1614             av_log(matroska->ctx, AV_LOG_INFO,
1615                    "Unknown or unsupported track type %"PRIu64"\n",
1616                    track->type);
1617             continue;
1618         }
1619         if (track->codec_id == NULL)
1620             continue;
1621
1622         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1623             if (!track->default_duration && track->video.frame_rate > 0)
1624                 track->default_duration = 1000000000/track->video.frame_rate;
1625             if (track->video.display_width == -1)
1626                 track->video.display_width = track->video.pixel_width;
1627             if (track->video.display_height == -1)
1628                 track->video.display_height = track->video.pixel_height;
1629             if (track->video.color_space.size == 4)
1630                 fourcc = AV_RL32(track->video.color_space.data);
1631         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1632             if (!track->audio.out_samplerate)
1633                 track->audio.out_samplerate = track->audio.samplerate;
1634         }
1635         if (encodings_list->nb_elem > 1) {
1636             av_log(matroska->ctx, AV_LOG_ERROR,
1637                    "Multiple combined encodings not supported");
1638         } else if (encodings_list->nb_elem == 1) {
1639             if (encodings[0].type) {
1640                 if (encodings[0].encryption.key_id.size > 0) {
1641                     /* Save the encryption key id to be stored later as a
1642                        metadata tag. */
1643                     const int b64_size = AV_BASE64_SIZE(encodings[0].encryption.key_id.size);
1644                     key_id_base64 = av_malloc(b64_size);
1645                     if (key_id_base64 == NULL)
1646                         return AVERROR(ENOMEM);
1647
1648                     av_base64_encode(key_id_base64, b64_size,
1649                                      encodings[0].encryption.key_id.data,
1650                                      encodings[0].encryption.key_id.size);
1651                 } else {
1652                     encodings[0].scope = 0;
1653                     av_log(matroska->ctx, AV_LOG_ERROR,
1654                            "Unsupported encoding type");
1655                 }
1656             } else if (
1657 #if CONFIG_ZLIB
1658                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_ZLIB &&
1659 #endif
1660 #if CONFIG_BZLIB
1661                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_BZLIB &&
1662 #endif
1663 #if CONFIG_LZO
1664                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_LZO &&
1665 #endif
1666                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP) {
1667                 encodings[0].scope = 0;
1668                 av_log(matroska->ctx, AV_LOG_ERROR,
1669                        "Unsupported encoding type");
1670             } else if (track->codec_priv.size && encodings[0].scope&2) {
1671                 uint8_t *codec_priv = track->codec_priv.data;
1672                 int ret = matroska_decode_buffer(&track->codec_priv.data,
1673                                                  &track->codec_priv.size,
1674                                                  track);
1675                 if (ret < 0) {
1676                     track->codec_priv.data = NULL;
1677                     track->codec_priv.size = 0;
1678                     av_log(matroska->ctx, AV_LOG_ERROR,
1679                            "Failed to decode codec private data\n");
1680                 }
1681
1682                 if (codec_priv != track->codec_priv.data)
1683                     av_free(codec_priv);
1684             }
1685         }
1686
1687         for(j=0; ff_mkv_codec_tags[j].id != AV_CODEC_ID_NONE; j++){
1688             if(!strncmp(ff_mkv_codec_tags[j].str, track->codec_id,
1689                         strlen(ff_mkv_codec_tags[j].str))){
1690                 codec_id= ff_mkv_codec_tags[j].id;
1691                 break;
1692             }
1693         }
1694
1695         st = track->stream = avformat_new_stream(s, NULL);
1696         if (st == NULL) {
1697             av_free(key_id_base64);
1698             return AVERROR(ENOMEM);
1699         }
1700
1701         if (key_id_base64) {
1702             /* export encryption key id as base64 metadata tag */
1703             av_dict_set(&st->metadata, "enc_key_id", key_id_base64, 0);
1704             av_freep(&key_id_base64);
1705         }
1706
1707         if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC")
1708             && track->codec_priv.size >= 40
1709             && track->codec_priv.data != NULL) {
1710             track->ms_compat = 1;
1711             fourcc = AV_RL32(track->codec_priv.data + 16);
1712             codec_id = ff_codec_get_id(ff_codec_bmp_tags, fourcc);
1713             extradata_offset = 40;
1714         } else if (!strcmp(track->codec_id, "A_MS/ACM")
1715                    && track->codec_priv.size >= 14
1716                    && track->codec_priv.data != NULL) {
1717             int ret;
1718             ffio_init_context(&b, track->codec_priv.data, track->codec_priv.size,
1719                               0, NULL, NULL, NULL, NULL);
1720             ret = ff_get_wav_header(&b, st->codec, track->codec_priv.size);
1721             if (ret < 0)
1722                 return ret;
1723             codec_id = st->codec->codec_id;
1724             extradata_offset = FFMIN(track->codec_priv.size, 18);
1725         } else if (!strcmp(track->codec_id, "V_QUICKTIME")
1726                    && (track->codec_priv.size >= 86)
1727                    && (track->codec_priv.data != NULL)) {
1728             fourcc = AV_RL32(track->codec_priv.data);
1729             codec_id = ff_codec_get_id(ff_codec_movvideo_tags, fourcc);
1730         } else if (codec_id == AV_CODEC_ID_PCM_S16BE) {
1731             switch (track->audio.bitdepth) {
1732             case  8:  codec_id = AV_CODEC_ID_PCM_U8;     break;
1733             case 24:  codec_id = AV_CODEC_ID_PCM_S24BE;  break;
1734             case 32:  codec_id = AV_CODEC_ID_PCM_S32BE;  break;
1735             }
1736         } else if (codec_id == AV_CODEC_ID_PCM_S16LE) {
1737             switch (track->audio.bitdepth) {
1738             case  8:  codec_id = AV_CODEC_ID_PCM_U8;     break;
1739             case 24:  codec_id = AV_CODEC_ID_PCM_S24LE;  break;
1740             case 32:  codec_id = AV_CODEC_ID_PCM_S32LE;  break;
1741             }
1742         } else if (codec_id==AV_CODEC_ID_PCM_F32LE && track->audio.bitdepth==64) {
1743             codec_id = AV_CODEC_ID_PCM_F64LE;
1744         } else if (codec_id == AV_CODEC_ID_AAC && !track->codec_priv.size) {
1745             int profile = matroska_aac_profile(track->codec_id);
1746             int sri = matroska_aac_sri(track->audio.samplerate);
1747             extradata = av_mallocz(5 + FF_INPUT_BUFFER_PADDING_SIZE);
1748             if (extradata == NULL)
1749                 return AVERROR(ENOMEM);
1750             extradata[0] = (profile << 3) | ((sri&0x0E) >> 1);
1751             extradata[1] = ((sri&0x01) << 7) | (track->audio.channels<<3);
1752             if (strstr(track->codec_id, "SBR")) {
1753                 sri = matroska_aac_sri(track->audio.out_samplerate);
1754                 extradata[2] = 0x56;
1755                 extradata[3] = 0xE5;
1756                 extradata[4] = 0x80 | (sri<<3);
1757                 extradata_size = 5;
1758             } else
1759                 extradata_size = 2;
1760         } else if (codec_id == AV_CODEC_ID_ALAC && track->codec_priv.size && track->codec_priv.size < INT_MAX - 12 - FF_INPUT_BUFFER_PADDING_SIZE) {
1761             /* Only ALAC's magic cookie is stored in Matroska's track headers.
1762                Create the "atom size", "tag", and "tag version" fields the
1763                decoder expects manually. */
1764             extradata_size = 12 + track->codec_priv.size;
1765             extradata = av_mallocz(extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
1766             if (extradata == NULL)
1767                 return AVERROR(ENOMEM);
1768             AV_WB32(extradata, extradata_size);
1769             memcpy(&extradata[4], "alac", 4);
1770             AV_WB32(&extradata[8], 0);
1771             memcpy(&extradata[12], track->codec_priv.data,
1772                                    track->codec_priv.size);
1773         } else if (codec_id == AV_CODEC_ID_TTA) {
1774             extradata_size = 30;
1775             extradata = av_mallocz(extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
1776             if (extradata == NULL)
1777                 return AVERROR(ENOMEM);
1778             ffio_init_context(&b, extradata, extradata_size, 1,
1779                           NULL, NULL, NULL, NULL);
1780             avio_write(&b, "TTA1", 4);
1781             avio_wl16(&b, 1);
1782             avio_wl16(&b, track->audio.channels);
1783             avio_wl16(&b, track->audio.bitdepth);
1784             if (track->audio.out_samplerate < 0 || track->audio.out_samplerate > INT_MAX)
1785                 return AVERROR_INVALIDDATA;
1786             avio_wl32(&b, track->audio.out_samplerate);
1787             avio_wl32(&b, av_rescale((matroska->duration * matroska->time_scale), track->audio.out_samplerate, AV_TIME_BASE * 1000));
1788         } else if (codec_id == AV_CODEC_ID_RV10 || codec_id == AV_CODEC_ID_RV20 ||
1789                    codec_id == AV_CODEC_ID_RV30 || codec_id == AV_CODEC_ID_RV40) {
1790             extradata_offset = 26;
1791         } else if (codec_id == AV_CODEC_ID_RA_144) {
1792             track->audio.out_samplerate = 8000;
1793             track->audio.channels = 1;
1794         } else if ((codec_id == AV_CODEC_ID_RA_288 || codec_id == AV_CODEC_ID_COOK ||
1795                     codec_id == AV_CODEC_ID_ATRAC3 || codec_id == AV_CODEC_ID_SIPR)
1796                     && track->codec_priv.data) {
1797             int flavor;
1798
1799             ffio_init_context(&b, track->codec_priv.data,track->codec_priv.size,
1800                           0, NULL, NULL, NULL, NULL);
1801             avio_skip(&b, 22);
1802             flavor                       = avio_rb16(&b);
1803             track->audio.coded_framesize = avio_rb32(&b);
1804             avio_skip(&b, 12);
1805             track->audio.sub_packet_h    = avio_rb16(&b);
1806             track->audio.frame_size      = avio_rb16(&b);
1807             track->audio.sub_packet_size = avio_rb16(&b);
1808             if (flavor < 0 || track->audio.coded_framesize <= 0 ||
1809                 track->audio.sub_packet_h <= 0 || track->audio.frame_size <= 0 ||
1810                 track->audio.sub_packet_size <= 0)
1811                 return AVERROR_INVALIDDATA;
1812             track->audio.buf = av_malloc_array(track->audio.sub_packet_h, track->audio.frame_size);
1813             if (!track->audio.buf)
1814                 return AVERROR(ENOMEM);
1815             if (codec_id == AV_CODEC_ID_RA_288) {
1816                 st->codec->block_align = track->audio.coded_framesize;
1817                 track->codec_priv.size = 0;
1818             } else {
1819                 if (codec_id == AV_CODEC_ID_SIPR && flavor < 4) {
1820                     static const int sipr_bit_rate[4] = { 6504, 8496, 5000, 16000 };
1821                     track->audio.sub_packet_size = ff_sipr_subpk_size[flavor];
1822                     st->codec->bit_rate = sipr_bit_rate[flavor];
1823                 }
1824                 st->codec->block_align = track->audio.sub_packet_size;
1825                 extradata_offset = 78;
1826             }
1827         }
1828         track->codec_priv.size -= extradata_offset;
1829
1830         if (codec_id == AV_CODEC_ID_NONE)
1831             av_log(matroska->ctx, AV_LOG_INFO,
1832                    "Unknown/unsupported AVCodecID %s.\n", track->codec_id);
1833
1834         if (track->time_scale < 0.01)
1835             track->time_scale = 1.0;
1836         avpriv_set_pts_info(st, 64, matroska->time_scale*track->time_scale, 1000*1000*1000); /* 64 bit pts in ns */
1837
1838         st->codec->codec_id = codec_id;
1839
1840         if (strcmp(track->language, "und"))
1841             av_dict_set(&st->metadata, "language", track->language, 0);
1842         av_dict_set(&st->metadata, "title", track->name, 0);
1843
1844         if (track->flag_default)
1845             st->disposition |= AV_DISPOSITION_DEFAULT;
1846         if (track->flag_forced)
1847             st->disposition |= AV_DISPOSITION_FORCED;
1848
1849         if (!st->codec->extradata) {
1850             if(extradata){
1851                 st->codec->extradata = extradata;
1852                 st->codec->extradata_size = extradata_size;
1853             } else if(track->codec_priv.data && track->codec_priv.size > 0){
1854                 if (ff_alloc_extradata(st->codec, track->codec_priv.size))
1855                     return AVERROR(ENOMEM);
1856                 memcpy(st->codec->extradata,
1857                        track->codec_priv.data + extradata_offset,
1858                        track->codec_priv.size);
1859             }
1860         }
1861
1862         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1863             MatroskaTrackPlane *planes = track->operation.combine_planes.elem;
1864
1865             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
1866             st->codec->codec_tag  = fourcc;
1867             st->codec->width  = track->video.pixel_width;
1868             st->codec->height = track->video.pixel_height;
1869             av_reduce(&st->sample_aspect_ratio.num,
1870                       &st->sample_aspect_ratio.den,
1871                       st->codec->height * track->video.display_width,
1872                       st->codec-> width * track->video.display_height,
1873                       255);
1874             if (st->codec->codec_id != AV_CODEC_ID_HEVC)
1875                 st->need_parsing = AVSTREAM_PARSE_HEADERS;
1876
1877             if (track->default_duration) {
1878                 av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
1879                           1000000000, track->default_duration, 30000);
1880 #if FF_API_R_FRAME_RATE
1881                 if (st->avg_frame_rate.num < st->avg_frame_rate.den * 1000L)
1882                     st->r_frame_rate = st->avg_frame_rate;
1883 #endif
1884             }
1885
1886             /* export stereo mode flag as metadata tag */
1887             if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREO_MODE_COUNT)
1888                 av_dict_set(&st->metadata, "stereo_mode", ff_matroska_video_stereo_mode[track->video.stereo_mode], 0);
1889
1890             /* export alpha mode flag as metadata tag  */
1891             if (track->video.alpha_mode)
1892                 av_dict_set(&st->metadata, "alpha_mode", "1", 0);
1893
1894             /* if we have virtual track, mark the real tracks */
1895             for (j=0; j < track->operation.combine_planes.nb_elem; j++) {
1896                 char buf[32];
1897                 if (planes[j].type >= MATROSKA_VIDEO_STEREO_PLANE_COUNT)
1898                     continue;
1899                 snprintf(buf, sizeof(buf), "%s_%d",
1900                          ff_matroska_video_stereo_plane[planes[j].type], i);
1901                 for (k=0; k < matroska->tracks.nb_elem; k++)
1902                     if (planes[j].uid == tracks[k].uid) {
1903                         av_dict_set(&s->streams[k]->metadata,
1904                                     "stereo_mode", buf, 0);
1905                         break;
1906                     }
1907             }
1908         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1909             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
1910             st->codec->sample_rate = track->audio.out_samplerate;
1911             st->codec->channels = track->audio.channels;
1912             st->codec->bits_per_coded_sample = track->audio.bitdepth;
1913             if (st->codec->codec_id != AV_CODEC_ID_AAC)
1914             st->need_parsing = AVSTREAM_PARSE_HEADERS;
1915             if (track->codec_delay > 0) {
1916                 st->codec->delay = av_rescale_q(track->codec_delay,
1917                                                 (AVRational){1, 1000000000},
1918                                                 (AVRational){1, st->codec->sample_rate});
1919             }
1920             if (track->seek_preroll > 0) {
1921                 av_codec_set_seek_preroll(st->codec,
1922                                           av_rescale_q(track->seek_preroll,
1923                                                        (AVRational){1, 1000000000},
1924                                                        (AVRational){1, st->codec->sample_rate}));
1925             }
1926         } else if (codec_id == AV_CODEC_ID_WEBVTT) {
1927             st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
1928
1929             if (!strcmp(track->codec_id, "D_WEBVTT/CAPTIONS")) {
1930                 st->disposition |= AV_DISPOSITION_CAPTIONS;
1931             } else if (!strcmp(track->codec_id, "D_WEBVTT/DESCRIPTIONS")) {
1932                 st->disposition |= AV_DISPOSITION_DESCRIPTIONS;
1933             } else if (!strcmp(track->codec_id, "D_WEBVTT/METADATA")) {
1934                 st->disposition |= AV_DISPOSITION_METADATA;
1935             }
1936         } else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
1937             st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
1938 #if FF_API_ASS_SSA
1939             if (st->codec->codec_id == AV_CODEC_ID_SSA ||
1940                 st->codec->codec_id == AV_CODEC_ID_ASS)
1941 #else
1942             if (st->codec->codec_id == AV_CODEC_ID_ASS)
1943 #endif
1944                 matroska->contains_ssa = 1;
1945         }
1946     }
1947
1948     attachements = attachements_list->elem;
1949     for (j=0; j<attachements_list->nb_elem; j++) {
1950         if (!(attachements[j].filename && attachements[j].mime &&
1951               attachements[j].bin.data && attachements[j].bin.size > 0)) {
1952             av_log(matroska->ctx, AV_LOG_ERROR, "incomplete attachment\n");
1953         } else {
1954             AVStream *st = avformat_new_stream(s, NULL);
1955             if (st == NULL)
1956                 break;
1957             av_dict_set(&st->metadata, "filename",attachements[j].filename, 0);
1958             av_dict_set(&st->metadata, "mimetype", attachements[j].mime, 0);
1959             st->codec->codec_id = AV_CODEC_ID_NONE;
1960             st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
1961             if (ff_alloc_extradata(st->codec, attachements[j].bin.size))
1962                 break;
1963             memcpy(st->codec->extradata, attachements[j].bin.data, attachements[j].bin.size);
1964
1965             for (i=0; ff_mkv_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
1966                 if (!strncmp(ff_mkv_mime_tags[i].str, attachements[j].mime,
1967                              strlen(ff_mkv_mime_tags[i].str))) {
1968                     st->codec->codec_id = ff_mkv_mime_tags[i].id;
1969                     break;
1970                 }
1971             }
1972             attachements[j].stream = st;
1973         }
1974     }
1975
1976     chapters = chapters_list->elem;
1977     for (i=0; i<chapters_list->nb_elem; i++)
1978         if (chapters[i].start != AV_NOPTS_VALUE && chapters[i].uid
1979             && (max_start==0 || chapters[i].start > max_start)) {
1980             chapters[i].chapter =
1981             avpriv_new_chapter(s, chapters[i].uid, (AVRational){1, 1000000000},
1982                            chapters[i].start, chapters[i].end,
1983                            chapters[i].title);
1984             av_dict_set(&chapters[i].chapter->metadata,
1985                              "title", chapters[i].title, 0);
1986             max_start = chapters[i].start;
1987         }
1988
1989     matroska_add_index_entries(matroska);
1990
1991     matroska_convert_tags(s);
1992
1993     return 0;
1994 }
1995
1996 /*
1997  * Put one packet in an application-supplied AVPacket struct.
1998  * Returns 0 on success or -1 on failure.
1999  */
2000 static int matroska_deliver_packet(MatroskaDemuxContext *matroska,
2001                                    AVPacket *pkt)
2002 {
2003     if (matroska->num_packets > 0) {
2004         memcpy(pkt, matroska->packets[0], sizeof(AVPacket));
2005         av_free(matroska->packets[0]);
2006         if (matroska->num_packets > 1) {
2007             void *newpackets;
2008             memmove(&matroska->packets[0], &matroska->packets[1],
2009                     (matroska->num_packets - 1) * sizeof(AVPacket *));
2010             newpackets = av_realloc(matroska->packets,
2011                             (matroska->num_packets - 1) * sizeof(AVPacket *));
2012             if (newpackets)
2013                 matroska->packets = newpackets;
2014         } else {
2015             av_freep(&matroska->packets);
2016             matroska->prev_pkt = NULL;
2017         }
2018         matroska->num_packets--;
2019         return 0;
2020     }
2021
2022     return -1;
2023 }
2024
2025 /*
2026  * Free all packets in our internal queue.
2027  */
2028 static void matroska_clear_queue(MatroskaDemuxContext *matroska)
2029 {
2030     matroska->prev_pkt = NULL;
2031     if (matroska->packets) {
2032         int n;
2033         for (n = 0; n < matroska->num_packets; n++) {
2034             av_free_packet(matroska->packets[n]);
2035             av_free(matroska->packets[n]);
2036         }
2037         av_freep(&matroska->packets);
2038         matroska->num_packets = 0;
2039     }
2040 }
2041
2042 static int matroska_parse_laces(MatroskaDemuxContext *matroska, uint8_t **buf,
2043                                 int* buf_size, int type,
2044                                 uint32_t **lace_buf, int *laces)
2045 {
2046     int res = 0, n, size = *buf_size;
2047     uint8_t *data = *buf;
2048     uint32_t *lace_size;
2049
2050     if (!type) {
2051         *laces = 1;
2052         *lace_buf = av_mallocz(sizeof(int));
2053         if (!*lace_buf)
2054             return AVERROR(ENOMEM);
2055
2056         *lace_buf[0] = size;
2057         return 0;
2058     }
2059
2060     av_assert0(size > 0);
2061     *laces = *data + 1;
2062     data += 1;
2063     size -= 1;
2064     lace_size = av_mallocz(*laces * sizeof(int));
2065     if (!lace_size)
2066         return AVERROR(ENOMEM);
2067
2068     switch (type) {
2069     case 0x1: /* Xiph lacing */ {
2070         uint8_t temp;
2071         uint32_t total = 0;
2072         for (n = 0; res == 0 && n < *laces - 1; n++) {
2073             while (1) {
2074                 if (size <= total) {
2075                     res = AVERROR_INVALIDDATA;
2076                     break;
2077                 }
2078                 temp = *data;
2079                 total += temp;
2080                 lace_size[n] += temp;
2081                 data += 1;
2082                 size -= 1;
2083                 if (temp != 0xff)
2084                     break;
2085             }
2086         }
2087         if (size <= total) {
2088             res = AVERROR_INVALIDDATA;
2089             break;
2090         }
2091
2092         lace_size[n] = size - total;
2093         break;
2094     }
2095
2096     case 0x2: /* fixed-size lacing */
2097         if (size % (*laces)) {
2098             res = AVERROR_INVALIDDATA;
2099             break;
2100         }
2101         for (n = 0; n < *laces; n++)
2102             lace_size[n] = size / *laces;
2103         break;
2104
2105     case 0x3: /* EBML lacing */ {
2106         uint64_t num;
2107         uint64_t total;
2108         n = matroska_ebmlnum_uint(matroska, data, size, &num);
2109         if (n < 0 || num > INT_MAX) {
2110             av_log(matroska->ctx, AV_LOG_INFO,
2111                    "EBML block data error\n");
2112             res = n<0 ? n : AVERROR_INVALIDDATA;
2113             break;
2114         }
2115         data += n;
2116         size -= n;
2117         total = lace_size[0] = num;
2118         for (n = 1; res == 0 && n < *laces - 1; n++) {
2119             int64_t snum;
2120             int r;
2121             r = matroska_ebmlnum_sint(matroska, data, size, &snum);
2122             if (r < 0 || lace_size[n - 1] + snum > (uint64_t)INT_MAX) {
2123                 av_log(matroska->ctx, AV_LOG_INFO,
2124                        "EBML block data error\n");
2125                 res = r<0 ? r : AVERROR_INVALIDDATA;
2126                 break;
2127             }
2128             data += r;
2129             size -= r;
2130             lace_size[n] = lace_size[n - 1] + snum;
2131             total += lace_size[n];
2132         }
2133         if (size <= total) {
2134             res = AVERROR_INVALIDDATA;
2135             break;
2136         }
2137         lace_size[*laces - 1] = size - total;
2138         break;
2139     }
2140     }
2141
2142     *buf      = data;
2143     *lace_buf = lace_size;
2144     *buf_size = size;
2145
2146     return res;
2147 }
2148
2149 static int matroska_parse_rm_audio(MatroskaDemuxContext *matroska,
2150                                    MatroskaTrack *track,
2151                                    AVStream *st,
2152                                    uint8_t *data, int size,
2153                                    uint64_t timecode,
2154                                    int64_t pos)
2155 {
2156     int a = st->codec->block_align;
2157     int sps = track->audio.sub_packet_size;
2158     int cfs = track->audio.coded_framesize;
2159     int h = track->audio.sub_packet_h;
2160     int y = track->audio.sub_packet_cnt;
2161     int w = track->audio.frame_size;
2162     int x;
2163
2164     if (!track->audio.pkt_cnt) {
2165         if (track->audio.sub_packet_cnt == 0)
2166             track->audio.buf_timecode = timecode;
2167         if (st->codec->codec_id == AV_CODEC_ID_RA_288) {
2168             if (size < cfs * h / 2) {
2169                 av_log(matroska->ctx, AV_LOG_ERROR,
2170                        "Corrupt int4 RM-style audio packet size\n");
2171                 return AVERROR_INVALIDDATA;
2172             }
2173             for (x=0; x<h/2; x++)
2174                 memcpy(track->audio.buf+x*2*w+y*cfs,
2175                        data+x*cfs, cfs);
2176         } else if (st->codec->codec_id == AV_CODEC_ID_SIPR) {
2177             if (size < w) {
2178                 av_log(matroska->ctx, AV_LOG_ERROR,
2179                        "Corrupt sipr RM-style audio packet size\n");
2180                 return AVERROR_INVALIDDATA;
2181             }
2182             memcpy(track->audio.buf + y*w, data, w);
2183         } else {
2184             if (size < sps * w / sps || h<=0) {
2185                 av_log(matroska->ctx, AV_LOG_ERROR,
2186                        "Corrupt generic RM-style audio packet size\n");
2187                 return AVERROR_INVALIDDATA;
2188             }
2189             for (x=0; x<w/sps; x++)
2190                 memcpy(track->audio.buf+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), data+x*sps, sps);
2191         }
2192
2193         if (++track->audio.sub_packet_cnt >= h) {
2194             if (st->codec->codec_id == AV_CODEC_ID_SIPR)
2195                 ff_rm_reorder_sipr_data(track->audio.buf, h, w);
2196             track->audio.sub_packet_cnt = 0;
2197             track->audio.pkt_cnt = h*w / a;
2198         }
2199     }
2200
2201     while (track->audio.pkt_cnt) {
2202         AVPacket *pkt = NULL;
2203         if (!(pkt = av_mallocz(sizeof(AVPacket))) || av_new_packet(pkt, a) < 0){
2204             av_free(pkt);
2205             return AVERROR(ENOMEM);
2206         }
2207         memcpy(pkt->data, track->audio.buf
2208                + a * (h*w / a - track->audio.pkt_cnt--), a);
2209         pkt->pts = track->audio.buf_timecode;
2210         track->audio.buf_timecode = AV_NOPTS_VALUE;
2211         pkt->pos = pos;
2212         pkt->stream_index = st->index;
2213         dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
2214     }
2215
2216     return 0;
2217 }
2218
2219 /* reconstruct full wavpack blocks from mangled matroska ones */
2220 static int matroska_parse_wavpack(MatroskaTrack *track, uint8_t *src,
2221                                   uint8_t **pdst, int *size)
2222 {
2223     uint8_t *dst = NULL;
2224     int dstlen   = 0;
2225     int srclen   = *size;
2226     uint32_t samples;
2227     uint16_t ver;
2228     int ret, offset = 0;
2229
2230     if (srclen < 12 || track->stream->codec->extradata_size < 2)
2231         return AVERROR_INVALIDDATA;
2232
2233     ver = AV_RL16(track->stream->codec->extradata);
2234
2235     samples = AV_RL32(src);
2236     src    += 4;
2237     srclen -= 4;
2238
2239     while (srclen >= 8) {
2240         int multiblock;
2241         uint32_t blocksize;
2242         uint8_t *tmp;
2243
2244         uint32_t flags = AV_RL32(src);
2245         uint32_t crc   = AV_RL32(src + 4);
2246         src    += 8;
2247         srclen -= 8;
2248
2249         multiblock = (flags & 0x1800) != 0x1800;
2250         if (multiblock) {
2251             if (srclen < 4) {
2252                 ret = AVERROR_INVALIDDATA;
2253                 goto fail;
2254             }
2255             blocksize = AV_RL32(src);
2256             src    += 4;
2257             srclen -= 4;
2258         } else
2259             blocksize = srclen;
2260
2261         if (blocksize > srclen) {
2262             ret = AVERROR_INVALIDDATA;
2263             goto fail;
2264         }
2265
2266         tmp = av_realloc(dst, dstlen + blocksize + 32);
2267         if (!tmp) {
2268             ret = AVERROR(ENOMEM);
2269             goto fail;
2270         }
2271         dst     = tmp;
2272         dstlen += blocksize + 32;
2273
2274         AV_WL32(dst + offset,      MKTAG('w', 'v', 'p', 'k')); // tag
2275         AV_WL32(dst + offset + 4,  blocksize + 24);            // blocksize - 8
2276         AV_WL16(dst + offset + 8,  ver);                       // version
2277         AV_WL16(dst + offset + 10, 0);                         // track/index_no
2278         AV_WL32(dst + offset + 12, 0);                         // total samples
2279         AV_WL32(dst + offset + 16, 0);                         // block index
2280         AV_WL32(dst + offset + 20, samples);                   // number of samples
2281         AV_WL32(dst + offset + 24, flags);                     // flags
2282         AV_WL32(dst + offset + 28, crc);                       // crc
2283         memcpy (dst + offset + 32, src, blocksize);            // block data
2284
2285         src    += blocksize;
2286         srclen -= blocksize;
2287         offset += blocksize + 32;
2288     }
2289
2290     *pdst = dst;
2291     *size = dstlen;
2292
2293     return 0;
2294
2295 fail:
2296     av_freep(&dst);
2297     return ret;
2298 }
2299
2300 static int matroska_parse_webvtt(MatroskaDemuxContext *matroska,
2301                                  MatroskaTrack *track,
2302                                  AVStream *st,
2303                                  uint8_t *data, int data_len,
2304                                  uint64_t timecode,
2305                                  uint64_t duration,
2306                                  int64_t pos)
2307 {
2308     AVPacket *pkt;
2309     uint8_t *id, *settings, *text, *buf;
2310     int id_len, settings_len, text_len;
2311     uint8_t *p, *q;
2312     int err;
2313
2314     if (data_len <= 0)
2315         return AVERROR_INVALIDDATA;
2316
2317     p = data;
2318     q = data + data_len;
2319
2320     id = p;
2321     id_len = -1;
2322     while (p < q) {
2323         if (*p == '\r' || *p == '\n') {
2324             id_len = p - id;
2325             if (*p == '\r')
2326                 p++;
2327             break;
2328         }
2329         p++;
2330     }
2331
2332     if (p >= q || *p != '\n')
2333         return AVERROR_INVALIDDATA;
2334     p++;
2335
2336     settings = p;
2337     settings_len = -1;
2338     while (p < q) {
2339         if (*p == '\r' || *p == '\n') {
2340             settings_len = p - settings;
2341             if (*p == '\r')
2342                 p++;
2343             break;
2344         }
2345         p++;
2346     }
2347
2348     if (p >= q || *p != '\n')
2349         return AVERROR_INVALIDDATA;
2350     p++;
2351
2352     text = p;
2353     text_len = q - p;
2354     while (text_len > 0) {
2355         const int len = text_len - 1;
2356         const uint8_t c = p[len];
2357         if (c != '\r' && c != '\n')
2358             break;
2359         text_len = len;
2360     }
2361
2362     if (text_len <= 0)
2363         return AVERROR_INVALIDDATA;
2364
2365     pkt = av_mallocz(sizeof(*pkt));
2366     err = av_new_packet(pkt, text_len);
2367     if (err < 0) {
2368         av_free(pkt);
2369         return AVERROR(err);
2370     }
2371
2372     memcpy(pkt->data, text, text_len);
2373
2374     if (id_len > 0) {
2375         buf = av_packet_new_side_data(pkt,
2376                                       AV_PKT_DATA_WEBVTT_IDENTIFIER,
2377                                       id_len);
2378         if (buf == NULL) {
2379             av_free(pkt);
2380             return AVERROR(ENOMEM);
2381         }
2382         memcpy(buf, id, id_len);
2383     }
2384
2385     if (settings_len > 0) {
2386         buf = av_packet_new_side_data(pkt,
2387                                       AV_PKT_DATA_WEBVTT_SETTINGS,
2388                                       settings_len);
2389         if (buf == NULL) {
2390             av_free(pkt);
2391             return AVERROR(ENOMEM);
2392         }
2393         memcpy(buf, settings, settings_len);
2394     }
2395
2396     // Do we need this for subtitles?
2397     // pkt->flags = AV_PKT_FLAG_KEY;
2398
2399     pkt->stream_index = st->index;
2400     pkt->pts = timecode;
2401
2402     // Do we need this for subtitles?
2403     // pkt->dts = timecode;
2404
2405     pkt->duration = duration;
2406     pkt->pos = pos;
2407
2408     dynarray_add(&matroska->packets, &matroska->num_packets, pkt);
2409     matroska->prev_pkt = pkt;
2410
2411     return 0;
2412 }
2413
2414 static int matroska_parse_frame(MatroskaDemuxContext *matroska,
2415                                 MatroskaTrack *track,
2416                                 AVStream *st,
2417                                 uint8_t *data, int pkt_size,
2418                                 uint64_t timecode, uint64_t lace_duration,
2419                                 int64_t pos, int is_keyframe,
2420                                 uint8_t *additional, uint64_t additional_id, int additional_size,
2421                                 int64_t discard_padding)
2422 {
2423     MatroskaTrackEncoding *encodings = track->encodings.elem;
2424     uint8_t *pkt_data = data;
2425     int offset = 0, res;
2426     AVPacket *pkt;
2427
2428     if (encodings && !encodings->type && encodings->scope & 1) {
2429         res = matroska_decode_buffer(&pkt_data, &pkt_size, track);
2430         if (res < 0)
2431             return res;
2432     }
2433
2434     if (st->codec->codec_id == AV_CODEC_ID_WAVPACK) {
2435         uint8_t *wv_data;
2436         res = matroska_parse_wavpack(track, pkt_data, &wv_data, &pkt_size);
2437         if (res < 0) {
2438             av_log(matroska->ctx, AV_LOG_ERROR, "Error parsing a wavpack block.\n");
2439             goto fail;
2440         }
2441         if (pkt_data != data)
2442             av_freep(&pkt_data);
2443         pkt_data = wv_data;
2444     }
2445
2446     if (st->codec->codec_id == AV_CODEC_ID_PRORES)
2447         offset = 8;
2448
2449     pkt = av_mallocz(sizeof(AVPacket));
2450     /* XXX: prevent data copy... */
2451     if (av_new_packet(pkt, pkt_size + offset) < 0) {
2452         av_free(pkt);
2453         res = AVERROR(ENOMEM);
2454         goto fail;
2455     }
2456
2457     if (st->codec->codec_id == AV_CODEC_ID_PRORES) {
2458         uint8_t *buf = pkt->data;
2459         bytestream_put_be32(&buf, pkt_size);
2460         bytestream_put_be32(&buf, MKBETAG('i', 'c', 'p', 'f'));
2461     }
2462
2463     memcpy(pkt->data + offset, pkt_data, pkt_size);
2464
2465     if (pkt_data != data)
2466         av_freep(&pkt_data);
2467
2468     pkt->flags = is_keyframe;
2469     pkt->stream_index = st->index;
2470
2471     if (additional_size > 0) {
2472         uint8_t *side_data = av_packet_new_side_data(pkt,
2473                                                      AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
2474                                                      additional_size + 8);
2475         if(side_data == NULL) {
2476             av_free_packet(pkt);
2477             av_free(pkt);
2478             return AVERROR(ENOMEM);
2479         }
2480         AV_WB64(side_data, additional_id);
2481         memcpy(side_data + 8, additional, additional_size);
2482     }
2483
2484     if (discard_padding) {
2485         uint8_t *side_data = av_packet_new_side_data(pkt,
2486                                                      AV_PKT_DATA_SKIP_SAMPLES,
2487                                                      10);
2488         if(side_data == NULL) {
2489             av_free_packet(pkt);
2490             av_free(pkt);
2491             return AVERROR(ENOMEM);
2492         }
2493         AV_WL32(side_data, 0);
2494         AV_WL32(side_data + 4, av_rescale_q(discard_padding,
2495                                             (AVRational){1, 1000000000},
2496                                             (AVRational){1, st->codec->sample_rate}));
2497     }
2498
2499     if (track->ms_compat)
2500         pkt->dts = timecode;
2501     else
2502         pkt->pts = timecode;
2503     pkt->pos = pos;
2504     if (st->codec->codec_id == AV_CODEC_ID_SUBRIP) {
2505         /*
2506          * For backward compatibility.
2507          * Historically, we have put subtitle duration
2508          * in convergence_duration, on the off chance
2509          * that the time_scale is less than 1us, which
2510          * could result in a 32bit overflow on the
2511          * normal duration field.
2512          */
2513         pkt->convergence_duration = lace_duration;
2514     }
2515
2516     if (track->type != MATROSKA_TRACK_TYPE_SUBTITLE ||
2517         lace_duration <= INT_MAX) {
2518         /*
2519          * For non subtitle tracks, just store the duration
2520          * as normal.
2521          *
2522          * If it's a subtitle track and duration value does
2523          * not overflow a uint32, then also store it normally.
2524          */
2525         pkt->duration = lace_duration;
2526     }
2527
2528 #if FF_API_ASS_SSA
2529     if (st->codec->codec_id == AV_CODEC_ID_SSA)
2530         matroska_fix_ass_packet(matroska, pkt, lace_duration);
2531
2532     if (matroska->prev_pkt &&
2533         timecode != AV_NOPTS_VALUE &&
2534         matroska->prev_pkt->pts == timecode &&
2535         matroska->prev_pkt->stream_index == st->index &&
2536         st->codec->codec_id == AV_CODEC_ID_SSA)
2537         matroska_merge_packets(matroska->prev_pkt, pkt);
2538     else {
2539         dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
2540         matroska->prev_pkt = pkt;
2541     }
2542 #else
2543     dynarray_add(&matroska->packets, &matroska->num_packets, pkt);
2544     matroska->prev_pkt = pkt;
2545 #endif
2546
2547     return 0;
2548 fail:
2549     if (pkt_data != data)
2550         av_freep(&pkt_data);
2551     return res;
2552 }
2553
2554 static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
2555                                 int size, int64_t pos, uint64_t cluster_time,
2556                                 uint64_t block_duration, int is_keyframe,
2557                                 uint8_t *additional, uint64_t additional_id, int additional_size,
2558                                 int64_t cluster_pos, int64_t discard_padding)
2559 {
2560     uint64_t timecode = AV_NOPTS_VALUE;
2561     MatroskaTrack *track;
2562     int res = 0;
2563     AVStream *st;
2564     int16_t block_time;
2565     uint32_t *lace_size = NULL;
2566     int n, flags, laces = 0;
2567     uint64_t num;
2568     int trust_default_duration = 1;
2569
2570     if ((n = matroska_ebmlnum_uint(matroska, data, size, &num)) < 0) {
2571         av_log(matroska->ctx, AV_LOG_ERROR, "EBML block data error\n");
2572         return n;
2573     }
2574     data += n;
2575     size -= n;
2576
2577     track = matroska_find_track_by_num(matroska, num);
2578     if (!track || !track->stream) {
2579         av_log(matroska->ctx, AV_LOG_INFO,
2580                "Invalid stream %"PRIu64" or size %u\n", num, size);
2581         return AVERROR_INVALIDDATA;
2582     } else if (size <= 3)
2583         return 0;
2584     st = track->stream;
2585     if (st->discard >= AVDISCARD_ALL)
2586         return res;
2587     av_assert1(block_duration != AV_NOPTS_VALUE);
2588
2589     block_time = sign_extend(AV_RB16(data), 16);
2590     data += 2;
2591     flags = *data++;
2592     size -= 3;
2593     if (is_keyframe == -1)
2594         is_keyframe = flags & 0x80 ? AV_PKT_FLAG_KEY : 0;
2595
2596     if (cluster_time != (uint64_t)-1
2597         && (block_time >= 0 || cluster_time >= -block_time)) {
2598         timecode = cluster_time + block_time;
2599         if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE
2600             && timecode < track->end_timecode)
2601             is_keyframe = 0;  /* overlapping subtitles are not key frame */
2602         if (is_keyframe)
2603             av_add_index_entry(st, cluster_pos, timecode, 0,0,AVINDEX_KEYFRAME);
2604     }
2605
2606     if (matroska->skip_to_keyframe && track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
2607         if (timecode < matroska->skip_to_timecode)
2608             return res;
2609         if (is_keyframe)
2610             matroska->skip_to_keyframe = 0;
2611         else if (!st->skip_to_keyframe) {
2612             av_log(matroska->ctx, AV_LOG_ERROR, "File is broken, keyframes not correctly marked!\n");
2613             matroska->skip_to_keyframe = 0;
2614         }
2615     }
2616
2617     res = matroska_parse_laces(matroska, &data, &size, (flags & 0x06) >> 1,
2618                                &lace_size, &laces);
2619
2620     if (res)
2621         goto end;
2622
2623     if (track->audio.samplerate == 8000) {
2624         // If this is needed for more codecs, then add them here
2625         if (st->codec->codec_id == AV_CODEC_ID_AC3) {
2626             if(track->audio.samplerate != st->codec->sample_rate || !st->codec->frame_size)
2627                 trust_default_duration = 0;
2628         }
2629     }
2630
2631     if (!block_duration && trust_default_duration)
2632         block_duration = track->default_duration * laces / matroska->time_scale;
2633
2634     if (cluster_time != (uint64_t)-1 && (block_time >= 0 || cluster_time >= -block_time))
2635         track->end_timecode =
2636             FFMAX(track->end_timecode, timecode + block_duration);
2637
2638     for (n = 0; n < laces; n++) {
2639         int64_t lace_duration = block_duration*(n+1) / laces - block_duration*n / laces;
2640
2641         if (lace_size[n] > size) {
2642             av_log(matroska->ctx, AV_LOG_ERROR, "Invalid packet size\n");
2643             break;
2644         }
2645
2646         if ((st->codec->codec_id == AV_CODEC_ID_RA_288 ||
2647              st->codec->codec_id == AV_CODEC_ID_COOK ||
2648              st->codec->codec_id == AV_CODEC_ID_SIPR ||
2649              st->codec->codec_id == AV_CODEC_ID_ATRAC3) &&
2650              st->codec->block_align && track->audio.sub_packet_size) {
2651
2652             res = matroska_parse_rm_audio(matroska, track, st, data,
2653                                           lace_size[n],
2654                                           timecode, pos);
2655             if (res)
2656                 goto end;
2657
2658         } else if (st->codec->codec_id == AV_CODEC_ID_WEBVTT) {
2659             res = matroska_parse_webvtt(matroska, track, st,
2660                                         data, lace_size[n],
2661                                         timecode, lace_duration,
2662                                         pos);
2663             if (res)
2664                 goto end;
2665
2666         } else {
2667             res = matroska_parse_frame(matroska, track, st, data, lace_size[n],
2668                                       timecode, lace_duration,
2669                                       pos, !n? is_keyframe : 0,
2670                                       additional, additional_id, additional_size,
2671                                       discard_padding);
2672             if (res)
2673                 goto end;
2674         }
2675
2676         if (timecode != AV_NOPTS_VALUE)
2677             timecode = lace_duration ? timecode + lace_duration : AV_NOPTS_VALUE;
2678         data += lace_size[n];
2679         size -= lace_size[n];
2680     }
2681
2682 end:
2683     av_free(lace_size);
2684     return res;
2685 }
2686
2687 static int matroska_parse_cluster_incremental(MatroskaDemuxContext *matroska)
2688 {
2689     EbmlList *blocks_list;
2690     MatroskaBlock *blocks;
2691     int i, res;
2692     res = ebml_parse(matroska,
2693                      matroska_cluster_incremental_parsing,
2694                      &matroska->current_cluster);
2695     if (res == 1) {
2696         /* New Cluster */
2697         if (matroska->current_cluster_pos)
2698             ebml_level_end(matroska);
2699         ebml_free(matroska_cluster, &matroska->current_cluster);
2700         memset(&matroska->current_cluster, 0, sizeof(MatroskaCluster));
2701         matroska->current_cluster_num_blocks = 0;
2702         matroska->current_cluster_pos = avio_tell(matroska->ctx->pb);
2703         matroska->prev_pkt = NULL;
2704         /* sizeof the ID which was already read */
2705         if (matroska->current_id)
2706             matroska->current_cluster_pos -= 4;
2707         res = ebml_parse(matroska,
2708                          matroska_clusters_incremental,
2709                          &matroska->current_cluster);
2710         /* Try parsing the block again. */
2711         if (res == 1)
2712             res = ebml_parse(matroska,
2713                              matroska_cluster_incremental_parsing,
2714                              &matroska->current_cluster);
2715     }
2716
2717     if (!res &&
2718         matroska->current_cluster_num_blocks <
2719             matroska->current_cluster.blocks.nb_elem) {
2720         blocks_list = &matroska->current_cluster.blocks;
2721         blocks = blocks_list->elem;
2722
2723         matroska->current_cluster_num_blocks = blocks_list->nb_elem;
2724         i = blocks_list->nb_elem - 1;
2725         if (blocks[i].bin.size > 0 && blocks[i].bin.data) {
2726             int is_keyframe = blocks[i].non_simple ? !blocks[i].reference : -1;
2727             uint8_t* additional = blocks[i].additional.size > 0 ?
2728                                     blocks[i].additional.data : NULL;
2729             if (!blocks[i].non_simple)
2730                 blocks[i].duration = 0;
2731             res = matroska_parse_block(matroska,
2732                                        blocks[i].bin.data, blocks[i].bin.size,
2733                                        blocks[i].bin.pos,
2734                                        matroska->current_cluster.timecode,
2735                                        blocks[i].duration, is_keyframe,
2736                                        additional, blocks[i].additional_id,
2737                                        blocks[i].additional.size,
2738                                        matroska->current_cluster_pos,
2739                                        blocks[i].discard_padding);
2740         }
2741     }
2742
2743     return res;
2744 }
2745
2746 static int matroska_parse_cluster(MatroskaDemuxContext *matroska)
2747 {
2748     MatroskaCluster cluster = { 0 };
2749     EbmlList *blocks_list;
2750     MatroskaBlock *blocks;
2751     int i, res;
2752     int64_t pos;
2753     if (!matroska->contains_ssa)
2754         return matroska_parse_cluster_incremental(matroska);
2755     pos = avio_tell(matroska->ctx->pb);
2756     matroska->prev_pkt = NULL;
2757     if (matroska->current_id)
2758         pos -= 4;  /* sizeof the ID which was already read */
2759     res = ebml_parse(matroska, matroska_clusters, &cluster);
2760     blocks_list = &cluster.blocks;
2761     blocks = blocks_list->elem;
2762     for (i=0; i<blocks_list->nb_elem; i++)
2763         if (blocks[i].bin.size > 0 && blocks[i].bin.data) {
2764             int is_keyframe = blocks[i].non_simple ? !blocks[i].reference : -1;
2765             res=matroska_parse_block(matroska,
2766                                      blocks[i].bin.data, blocks[i].bin.size,
2767                                      blocks[i].bin.pos,  cluster.timecode,
2768                                      blocks[i].duration, is_keyframe, NULL, 0, 0,
2769                                      pos, blocks[i].discard_padding);
2770         }
2771     ebml_free(matroska_cluster, &cluster);
2772     return res;
2773 }
2774
2775 static int matroska_read_packet(AVFormatContext *s, AVPacket *pkt)
2776 {
2777     MatroskaDemuxContext *matroska = s->priv_data;
2778
2779     while (matroska_deliver_packet(matroska, pkt)) {
2780         int64_t pos = avio_tell(matroska->ctx->pb);
2781         if (matroska->done)
2782             return AVERROR_EOF;
2783         if (matroska_parse_cluster(matroska) < 0)
2784             matroska_resync(matroska, pos);
2785     }
2786
2787     return 0;
2788 }
2789
2790 static int matroska_read_seek(AVFormatContext *s, int stream_index,
2791                               int64_t timestamp, int flags)
2792 {
2793     MatroskaDemuxContext *matroska = s->priv_data;
2794     MatroskaTrack *tracks = matroska->tracks.elem;
2795     AVStream *st = s->streams[stream_index];
2796     int i, index, index_sub, index_min;
2797
2798     /* Parse the CUES now since we need the index data to seek. */
2799     if (matroska->cues_parsing_deferred > 0) {
2800         matroska->cues_parsing_deferred = 0;
2801         matroska_parse_cues(matroska);
2802     }
2803
2804     if (!st->nb_index_entries)
2805         goto err;
2806     timestamp = FFMAX(timestamp, st->index_entries[0].timestamp);
2807
2808     if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
2809         avio_seek(s->pb, st->index_entries[st->nb_index_entries-1].pos, SEEK_SET);
2810         matroska->current_id = 0;
2811         while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
2812             matroska_clear_queue(matroska);
2813             if (matroska_parse_cluster(matroska) < 0)
2814                 break;
2815         }
2816     }
2817
2818     matroska_clear_queue(matroska);
2819     if (index < 0 || (matroska->cues_parsing_deferred < 0 && index == st->nb_index_entries - 1))
2820         goto err;
2821
2822     index_min = index;
2823     for (i=0; i < matroska->tracks.nb_elem; i++) {
2824         tracks[i].audio.pkt_cnt = 0;
2825         tracks[i].audio.sub_packet_cnt = 0;
2826         tracks[i].audio.buf_timecode = AV_NOPTS_VALUE;
2827         tracks[i].end_timecode = 0;
2828         if (tracks[i].type == MATROSKA_TRACK_TYPE_SUBTITLE
2829             && tracks[i].stream->discard != AVDISCARD_ALL) {
2830             index_sub = av_index_search_timestamp(tracks[i].stream, st->index_entries[index].timestamp, AVSEEK_FLAG_BACKWARD);
2831             while(index_sub >= 0
2832                   && index_min >= 0
2833                   && tracks[i].stream->index_entries[index_sub].pos < st->index_entries[index_min].pos
2834                   && st->index_entries[index].timestamp - tracks[i].stream->index_entries[index_sub].timestamp < 30000000000/matroska->time_scale)
2835                 index_min--;
2836         }
2837     }
2838
2839     avio_seek(s->pb, st->index_entries[index_min].pos, SEEK_SET);
2840     matroska->current_id = 0;
2841     if (flags & AVSEEK_FLAG_ANY) {
2842         st->skip_to_keyframe = 0;
2843         matroska->skip_to_timecode = timestamp;
2844     } else {
2845         st->skip_to_keyframe = 1;
2846         matroska->skip_to_timecode = st->index_entries[index].timestamp;
2847     }
2848     matroska->skip_to_keyframe = 1;
2849     matroska->done = 0;
2850     matroska->num_levels = 0;
2851     ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
2852     return 0;
2853 err:
2854     // slightly hackish but allows proper fallback to
2855     // the generic seeking code.
2856     matroska_clear_queue(matroska);
2857     matroska->current_id = 0;
2858     st->skip_to_keyframe =
2859     matroska->skip_to_keyframe = 0;
2860     matroska->done = 0;
2861     matroska->num_levels = 0;
2862     return -1;
2863 }
2864
2865 static int matroska_read_close(AVFormatContext *s)
2866 {
2867     MatroskaDemuxContext *matroska = s->priv_data;
2868     MatroskaTrack *tracks = matroska->tracks.elem;
2869     int n;
2870
2871     matroska_clear_queue(matroska);
2872
2873     for (n=0; n < matroska->tracks.nb_elem; n++)
2874         if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)
2875             av_free(tracks[n].audio.buf);
2876     ebml_free(matroska_cluster, &matroska->current_cluster);
2877     ebml_free(matroska_segment, matroska);
2878
2879     return 0;
2880 }
2881
2882 AVInputFormat ff_matroska_demuxer = {
2883     .name           = "matroska,webm",
2884     .long_name      = NULL_IF_CONFIG_SMALL("Matroska / WebM"),
2885     .priv_data_size = sizeof(MatroskaDemuxContext),
2886     .read_probe     = matroska_probe,
2887     .read_header    = matroska_read_header,
2888     .read_packet    = matroska_read_packet,
2889     .read_close     = matroska_read_close,
2890     .read_seek      = matroska_read_seek,
2891 };