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

   1 /*
   2  * Matroska file demuxer (no muxer yet)
   3  * Copyright (c) 2003-2004 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 matroskadec.c
  24  * Matroska file demuxer
  25  * by Ronald Bultje <rbultje@ronald.bitfreak.net>
  26  * with a little help from Moritz Bunkus <moritz@bunkus.org>
  27  * Specs available on the matroska project page:
  28  * http://www.matroska.org/.
  29  */
  30
  31 #include "avformat.h"
  32 /* For codec_get_id(). */
  33 #include "riff.h"
  34 #include "isom.h"
  35 #include "matroska.h"
  36 #include "libavcodec/mpeg4audio.h"
  37 #include "libavutil/intfloat_readwrite.h"
  38 #include "libavutil/avstring.h"
  39 #include "libavutil/lzo.h"
  40 #ifdef CONFIG_ZLIB
  41 #include <zlib.h>
  42 #endif
  43 #ifdef CONFIG_BZLIB
  44 #include <bzlib.h>
  45 #endif
  46
  47 typedef enum {
  48     EBML_NONE,
  49     EBML_UINT,
  50     EBML_FLOAT,
  51     EBML_STR,
  52     EBML_UTF8,
  53     EBML_BIN,
  54     EBML_NEST,
  55     EBML_PASS,
  56     EBML_STOP,
  57 } EbmlType;
  58
  59 typedef const struct EbmlSyntax {
  60     uint32_t id;
  61     EbmlType type;
  62     int list_elem_size;
  63     int data_offset;
  64     union {
  65         uint64_t    u;
  66         double      f;
  67         const char *s;
  68         const struct EbmlSyntax *n;
  69     } def;
  70 } EbmlSyntax;
  71
  72 typedef struct {
  73     int nb_elem;
  74     void *elem;
  75 } EbmlList;
  76
  77 typedef struct {
  78     int      size;
  79     uint8_t *data;
  80     int64_t  pos;
  81 } EbmlBin;
  82
  83 typedef struct {
  84     uint64_t version;
  85     uint64_t max_size;
  86     uint64_t id_length;
  87     char    *doctype;
  88     uint64_t doctype_version;
  89 } Ebml;
  90
  91 typedef struct {
  92     uint64_t algo;
  93     EbmlBin  settings;
  94 } MatroskaTrackCompression;
  95
  96 typedef struct {
  97     uint64_t scope;
  98     uint64_t type;
  99     MatroskaTrackCompression compression;
 100 } MatroskaTrackEncoding;
 101
 102 typedef struct {
 103     double   frame_rate;
 104     uint64_t display_width;
 105     uint64_t display_height;
 106     uint64_t pixel_width;
 107     uint64_t pixel_height;
 108     uint64_t fourcc;
 109 } MatroskaTrackVideo;
 110
 111 typedef struct {
 112     double   samplerate;
 113     double   out_samplerate;
 114     uint64_t bitdepth;
 115     uint64_t channels;
 116
 117     /* real audio header (extracted from extradata) */
 118     int      coded_framesize;
 119     int      sub_packet_h;
 120     int      frame_size;
 121     int      sub_packet_size;
 122     int      sub_packet_cnt;
 123     int      pkt_cnt;
 124     uint8_t *buf;
 125 } MatroskaTrackAudio;
 126
 127 typedef struct {
 128     uint64_t num;
 129     uint64_t type;
 130     char    *codec_id;
 131     EbmlBin  codec_priv;
 132     char    *language;
 133     double time_scale;
 134     uint64_t default_duration;
 135     uint64_t flag_default;
 136     MatroskaTrackVideo video;
 137     MatroskaTrackAudio audio;
 138     EbmlList encodings;
 139
 140     AVStream *stream;
 141 } MatroskaTrack;
 142
 143 typedef struct {
 144     char *filename;
 145     char *mime;
 146     EbmlBin bin;
 147 } MatroskaAttachement;
 148
 149 typedef struct {
 150     uint64_t start;
 151     uint64_t end;
 152     uint64_t uid;
 153     char    *title;
 154 } MatroskaChapter;
 155
 156 typedef struct {
 157     uint64_t track;
 158     uint64_t pos;
 159 } MatroskaIndexPos;
 160
 161 typedef struct {
 162     uint64_t time;
 163     EbmlList pos;
 164 } MatroskaIndex;
 165
 166 typedef struct {
 167     uint64_t id;
 168     uint64_t pos;
 169 } MatroskaSeekhead;
 170
 171 typedef struct {
 172     uint64_t start;
 173     uint64_t length;
 174 } MatroskaLevel;
 175
 176 typedef struct {
 177     AVFormatContext *ctx;
 178
 179     /* ebml stuff */
 180     int num_levels;
 181     MatroskaLevel levels[EBML_MAX_DEPTH];
 182     int level_up;
 183
 184     uint64_t time_scale;
 185     double   duration;
 186     char    *title;
 187     EbmlList tracks;
 188     EbmlList attachments;
 189     EbmlList chapters;
 190     EbmlList index;
 191     EbmlList seekhead;
 192
 193     /* num_streams is the number of streams that av_new_stream() was called
 194      * for ( = that are available to the calling program). */
 195     int num_streams;
 196
 197     /* cache for ID peeking */
 198     uint32_t peek_id;
 199
 200     /* byte position of the segment inside the stream */
 201     offset_t segment_start;
 202
 203     /* The packet queue. */
 204     AVPacket **packets;
 205     int num_packets;
 206
 207     int done;
 208     int has_cluster_id;
 209
 210     /* What to skip before effectively reading a packet. */
 211     int skip_to_keyframe;
 212     AVStream *skip_to_stream;
 213 } MatroskaDemuxContext;
 214
 215 typedef struct {
 216     uint64_t duration;
 217     int64_t  reference;
 218     EbmlBin  bin;
 219 } MatroskaBlock;
 220
 221 typedef struct {
 222     uint64_t timecode;
 223     EbmlList blocks;
 224 } MatroskaCluster;
 225
 226 #define ARRAY_SIZE(x)  (sizeof(x)/sizeof(*x))
 227
 228 static EbmlSyntax ebml_header[] = {
 229     { EBML_ID_EBMLREADVERSION,        EBML_UINT, 0, offsetof(Ebml,version), {.u=EBML_VERSION} },
 230     { EBML_ID_EBMLMAXSIZELENGTH,      EBML_UINT, 0, offsetof(Ebml,max_size), {.u=8} },
 231     { EBML_ID_EBMLMAXIDLENGTH,        EBML_UINT, 0, offsetof(Ebml,id_length), {.u=4} },
 232     { EBML_ID_DOCTYPE,                EBML_STR,  0, offsetof(Ebml,doctype), {.s="(none)"} },
 233     { EBML_ID_DOCTYPEREADVERSION,     EBML_UINT, 0, offsetof(Ebml,doctype_version), {.u=1} },
 234     { EBML_ID_EBMLVERSION,            EBML_NONE },
 235     { EBML_ID_DOCTYPEVERSION,         EBML_NONE },
 236     { EBML_ID_VOID,                   EBML_NONE },
 237     { 0 }
 238 };
 239
 240 static EbmlSyntax ebml_syntax[] = {
 241     { EBML_ID_HEADER,                 EBML_NEST, 0, 0, {.n=ebml_header} },
 242     { 0 }
 243 };
 244
 245 static EbmlSyntax matroska_info[] = {
 246     { MATROSKA_ID_TIMECODESCALE,      EBML_UINT,  0, offsetof(MatroskaDemuxContext,time_scale), {.u=1000000} },
 247     { MATROSKA_ID_DURATION,           EBML_FLOAT, 0, offsetof(MatroskaDemuxContext,duration) },
 248     { MATROSKA_ID_TITLE,              EBML_UTF8,  0, offsetof(MatroskaDemuxContext,title) },
 249     { MATROSKA_ID_WRITINGAPP,         EBML_NONE },
 250     { MATROSKA_ID_MUXINGAPP,          EBML_NONE },
 251     { MATROSKA_ID_DATEUTC,            EBML_NONE },
 252     { MATROSKA_ID_SEGMENTUID,         EBML_NONE },
 253     { EBML_ID_VOID,                   EBML_NONE },
 254     { 0 }
 255 };
 256
 257 static EbmlSyntax matroska_track_video[] = {
 258     { MATROSKA_ID_VIDEOFRAMERATE,     EBML_FLOAT,0, offsetof(MatroskaTrackVideo,frame_rate) },
 259     { MATROSKA_ID_VIDEODISPLAYWIDTH,  EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_width) },
 260     { MATROSKA_ID_VIDEODISPLAYHEIGHT, EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_height) },
 261     { MATROSKA_ID_VIDEOPIXELWIDTH,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_width) },
 262     { MATROSKA_ID_VIDEOPIXELHEIGHT,   EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_height) },
 263     { MATROSKA_ID_VIDEOCOLORSPACE,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,fourcc) },
 264     { MATROSKA_ID_VIDEOFLAGINTERLACED,EBML_NONE },
 265     { MATROSKA_ID_VIDEOSTEREOMODE,    EBML_NONE },
 266     { MATROSKA_ID_VIDEOASPECTRATIO,   EBML_NONE },
 267     { EBML_ID_VOID,                   EBML_NONE },
 268     { 0 }
 269 };
 270
 271 static EbmlSyntax matroska_track_audio[] = {
 272     { MATROSKA_ID_AUDIOSAMPLINGFREQ,  EBML_FLOAT,0, offsetof(MatroskaTrackAudio,samplerate), {.f=8000.0} },
 273     { MATROSKA_ID_AUDIOOUTSAMPLINGFREQ,EBML_FLOAT,0,offsetof(MatroskaTrackAudio,out_samplerate) },
 274     { MATROSKA_ID_AUDIOBITDEPTH,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,bitdepth) },
 275     { MATROSKA_ID_AUDIOCHANNELS,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,channels), {.u=1} },
 276     { EBML_ID_VOID,                   EBML_NONE },
 277     { 0 }
 278 };
 279
 280 static EbmlSyntax matroska_track_encoding_compression[] = {
 281     { MATROSKA_ID_ENCODINGCOMPALGO,   EBML_UINT, 0, offsetof(MatroskaTrackCompression,algo), {.u=0} },
 282     { MATROSKA_ID_ENCODINGCOMPSETTINGS,EBML_BIN, 0, offsetof(MatroskaTrackCompression,settings) },
 283     { EBML_ID_VOID,                   EBML_NONE },
 284     { 0 }
 285 };
 286
 287 static EbmlSyntax matroska_track_encoding[] = {
 288     { MATROSKA_ID_ENCODINGSCOPE,      EBML_UINT, 0, offsetof(MatroskaTrackEncoding,scope), {.u=1} },
 289     { MATROSKA_ID_ENCODINGTYPE,       EBML_UINT, 0, offsetof(MatroskaTrackEncoding,type), {.u=0} },
 290     { MATROSKA_ID_ENCODINGCOMPRESSION,EBML_NEST, 0, offsetof(MatroskaTrackEncoding,compression), {.n=matroska_track_encoding_compression} },
 291     { EBML_ID_VOID,                   EBML_NONE },
 292     { 0 }
 293 };
 294
 295 static EbmlSyntax matroska_track_encodings[] = {
 296     { MATROSKA_ID_TRACKCONTENTENCODING, EBML_NEST, sizeof(MatroskaTrackEncoding), offsetof(MatroskaTrack,encodings), {.n=matroska_track_encoding} },
 297     { EBML_ID_VOID,                   EBML_NONE },
 298     { 0 }
 299 };
 300
 301 static EbmlSyntax matroska_track[] = {
 302     { MATROSKA_ID_TRACKNUMBER,          EBML_UINT, 0, offsetof(MatroskaTrack,num) },
 303     { MATROSKA_ID_TRACKTYPE,            EBML_UINT, 0, offsetof(MatroskaTrack,type) },
 304     { MATROSKA_ID_CODECID,              EBML_STR,  0, offsetof(MatroskaTrack,codec_id) },
 305     { MATROSKA_ID_CODECPRIVATE,         EBML_BIN,  0, offsetof(MatroskaTrack,codec_priv) },
 306     { MATROSKA_ID_TRACKLANGUAGE,        EBML_UTF8, 0, offsetof(MatroskaTrack,language), {.s="eng"} },
 307     { MATROSKA_ID_TRACKDEFAULTDURATION, EBML_UINT, 0, offsetof(MatroskaTrack,default_duration) },
 308     { MATROSKA_ID_TRACKTIMECODESCALE,   EBML_FLOAT,0, offsetof(MatroskaTrack,time_scale), {.f=1.0} },
 309     { MATROSKA_ID_TRACKFLAGDEFAULT,     EBML_UINT, 0, offsetof(MatroskaTrack,flag_default), {.u=1} },
 310     { MATROSKA_ID_TRACKVIDEO,           EBML_NEST, 0, offsetof(MatroskaTrack,video), {.n=matroska_track_video} },
 311     { MATROSKA_ID_TRACKAUDIO,           EBML_NEST, 0, offsetof(MatroskaTrack,audio), {.n=matroska_track_audio} },
 312     { MATROSKA_ID_TRACKCONTENTENCODINGS,EBML_NEST, 0, 0, {.n=matroska_track_encodings} },
 313     { MATROSKA_ID_TRACKUID,             EBML_NONE },
 314     { MATROSKA_ID_TRACKNAME,            EBML_NONE },
 315     { MATROSKA_ID_TRACKFLAGENABLED,     EBML_NONE },
 316     { MATROSKA_ID_TRACKFLAGFORCED,      EBML_NONE },
 317     { MATROSKA_ID_TRACKFLAGLACING,      EBML_NONE },
 318     { MATROSKA_ID_CODECNAME,            EBML_NONE },
 319     { MATROSKA_ID_CODECDECODEALL,       EBML_NONE },
 320     { MATROSKA_ID_CODECINFOURL,         EBML_NONE },
 321     { MATROSKA_ID_CODECDOWNLOADURL,     EBML_NONE },
 322     { MATROSKA_ID_TRACKMINCACHE,        EBML_NONE },
 323     { MATROSKA_ID_TRACKMAXCACHE,        EBML_NONE },
 324     { EBML_ID_VOID,                     EBML_NONE },
 325     { 0 }
 326 };
 327
 328 static EbmlSyntax matroska_tracks[] = {
 329     { MATROSKA_ID_TRACKENTRY,         EBML_NEST, sizeof(MatroskaTrack), offsetof(MatroskaDemuxContext,tracks), {.n=matroska_track} },
 330     { EBML_ID_VOID,                   EBML_NONE },
 331     { 0 }
 332 };
 333
 334 static EbmlSyntax matroska_attachment[] = {
 335     { MATROSKA_ID_FILENAME,           EBML_UTF8, 0, offsetof(MatroskaAttachement,filename) },
 336     { MATROSKA_ID_FILEMIMETYPE,       EBML_STR,  0, offsetof(MatroskaAttachement,mime) },
 337     { MATROSKA_ID_FILEDATA,           EBML_BIN,  0, offsetof(MatroskaAttachement,bin) },
 338     { MATROSKA_ID_FILEUID,            EBML_NONE },
 339     { EBML_ID_VOID,                   EBML_NONE },
 340     { 0 }
 341 };
 342
 343 static EbmlSyntax matroska_attachments[] = {
 344     { MATROSKA_ID_ATTACHEDFILE,       EBML_NEST, sizeof(MatroskaAttachement), offsetof(MatroskaDemuxContext,attachments), {.n=matroska_attachment} },
 345     { EBML_ID_VOID,                   EBML_NONE },
 346     { 0 }
 347 };
 348
 349 static EbmlSyntax matroska_chapter_display[] = {
 350     { MATROSKA_ID_CHAPSTRING,         EBML_UTF8, 0, offsetof(MatroskaChapter,title) },
 351     { EBML_ID_VOID,                   EBML_NONE },
 352     { 0 }
 353 };
 354
 355 static EbmlSyntax matroska_chapter_entry[] = {
 356     { MATROSKA_ID_CHAPTERTIMESTART,   EBML_UINT, 0, offsetof(MatroskaChapter,start), {.u=AV_NOPTS_VALUE} },
 357     { MATROSKA_ID_CHAPTERTIMEEND,     EBML_UINT, 0, offsetof(MatroskaChapter,end), {.u=AV_NOPTS_VALUE} },
 358     { MATROSKA_ID_CHAPTERUID,         EBML_UINT, 0, offsetof(MatroskaChapter,uid) },
 359     { MATROSKA_ID_CHAPTERDISPLAY,     EBML_NEST, 0, 0, {.n=matroska_chapter_display} },
 360     { MATROSKA_ID_CHAPTERFLAGHIDDEN,  EBML_NONE },
 361     { EBML_ID_VOID,                   EBML_NONE },
 362     { 0 }
 363 };
 364
 365 static EbmlSyntax matroska_chapter[] = {
 366     { MATROSKA_ID_CHAPTERATOM,        EBML_NEST, sizeof(MatroskaChapter), offsetof(MatroskaDemuxContext,chapters), {.n=matroska_chapter_entry} },
 367     { MATROSKA_ID_EDITIONUID,         EBML_NONE },
 368     { MATROSKA_ID_EDITIONFLAGHIDDEN,  EBML_NONE },
 369     { MATROSKA_ID_EDITIONFLAGDEFAULT, EBML_NONE },
 370     { EBML_ID_VOID,                   EBML_NONE },
 371     { 0 }
 372 };
 373
 374 static EbmlSyntax matroska_chapters[] = {
 375     { MATROSKA_ID_EDITIONENTRY,       EBML_NEST, 0, 0, {.n=matroska_chapter} },
 376     { EBML_ID_VOID,                   EBML_NONE },
 377     { 0 }
 378 };
 379
 380 static EbmlSyntax matroska_index_pos[] = {
 381     { MATROSKA_ID_CUETRACK,           EBML_UINT, 0, offsetof(MatroskaIndexPos,track) },
 382     { MATROSKA_ID_CUECLUSTERPOSITION, EBML_UINT, 0, offsetof(MatroskaIndexPos,pos)   },
 383     { EBML_ID_VOID,                   EBML_NONE },
 384     { 0 }
 385 };
 386
 387 static EbmlSyntax matroska_index_entry[] = {
 388     { MATROSKA_ID_CUETIME,            EBML_UINT, 0, offsetof(MatroskaIndex,time) },
 389     { MATROSKA_ID_CUETRACKPOSITION,   EBML_NEST, sizeof(MatroskaIndexPos), offsetof(MatroskaIndex,pos), {.n=matroska_index_pos} },
 390     { EBML_ID_VOID,                   EBML_NONE },
 391     { 0 }
 392 };
 393
 394 static EbmlSyntax matroska_index[] = {
 395     { MATROSKA_ID_POINTENTRY,         EBML_NEST, sizeof(MatroskaIndex), offsetof(MatroskaDemuxContext,index), {.n=matroska_index_entry} },
 396     { EBML_ID_VOID,                   EBML_NONE },
 397     { 0 }
 398 };
 399
 400 static EbmlSyntax matroska_tags[] = {
 401     { EBML_ID_VOID,                   EBML_NONE },
 402     { 0 }
 403 };
 404
 405 static EbmlSyntax matroska_seekhead_entry[] = {
 406     { MATROSKA_ID_SEEKID,             EBML_UINT, 0, offsetof(MatroskaSeekhead,id) },
 407     { MATROSKA_ID_SEEKPOSITION,       EBML_UINT, 0, offsetof(MatroskaSeekhead,pos), {.u=-1} },
 408     { EBML_ID_VOID,                   EBML_NONE },
 409     { 0 }
 410 };
 411
 412 static EbmlSyntax matroska_seekhead[] = {
 413     { MATROSKA_ID_SEEKENTRY,          EBML_NEST, sizeof(MatroskaSeekhead), offsetof(MatroskaDemuxContext,seekhead), {.n=matroska_seekhead_entry} },
 414     { EBML_ID_VOID,                   EBML_NONE },
 415     { 0 }
 416 };
 417
 418 static EbmlSyntax matroska_segment[] = {
 419     { MATROSKA_ID_INFO,           EBML_NEST, 0, 0, {.n=matroska_info       } },
 420     { MATROSKA_ID_TRACKS,         EBML_NEST, 0, 0, {.n=matroska_tracks     } },
 421     { MATROSKA_ID_ATTACHMENTS,    EBML_NEST, 0, 0, {.n=matroska_attachments} },
 422     { MATROSKA_ID_CHAPTERS,       EBML_NEST, 0, 0, {.n=matroska_chapters   } },
 423     { MATROSKA_ID_CUES,           EBML_NEST, 0, 0, {.n=matroska_index      } },
 424     { MATROSKA_ID_TAGS,           EBML_NEST, 0, 0, {.n=matroska_tags       } },
 425     { MATROSKA_ID_SEEKHEAD,       EBML_NEST, 0, 0, {.n=matroska_seekhead   } },
 426     { MATROSKA_ID_CLUSTER,        EBML_STOP, 0, offsetof(MatroskaDemuxContext,has_cluster_id) },
 427     { EBML_ID_VOID,               EBML_NONE },
 428     { 0 }
 429 };
 430
 431 static EbmlSyntax matroska_segments[] = {
 432     { MATROSKA_ID_SEGMENT,        EBML_NEST, 0, 0, {.n=matroska_segment    } },
 433     { 0 }
 434 };
 435
 436 static EbmlSyntax matroska_blockgroup[] = {
 437     { MATROSKA_ID_BLOCK,          EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
 438     { MATROSKA_ID_SIMPLEBLOCK,    EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
 439     { MATROSKA_ID_BLOCKDURATION,  EBML_UINT, 0, offsetof(MatroskaBlock,duration), {.u=AV_NOPTS_VALUE} },
 440     { MATROSKA_ID_BLOCKREFERENCE, EBML_UINT, 0, offsetof(MatroskaBlock,reference) },
 441     { EBML_ID_VOID,               EBML_NONE },
 442     { 0 }
 443 };
 444
 445 static EbmlSyntax matroska_cluster[] = {
 446     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
 447     { MATROSKA_ID_BLOCKGROUP,     EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 448     { MATROSKA_ID_SIMPLEBLOCK,    EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 449     { EBML_ID_VOID,               EBML_NONE },
 450     { 0 }
 451 };
 452
 453 static EbmlSyntax matroska_clusters[] = {
 454     { MATROSKA_ID_CLUSTER,        EBML_NEST, 0, 0, {.n=matroska_cluster} },
 455     { 0 }
 456 };
 457
 458 /*
 459  * Return: the amount of levels in the hierarchy that the
 460  * current element lies higher than the previous one.
 461  * The opposite isn't done - that's auto-done using master
 462  * element reading.
 463  */
 464 static int
 465 ebml_read_element_level_up (MatroskaDemuxContext *matroska)
 466 {
 467     ByteIOContext *pb = matroska->ctx->pb;
 468     offset_t pos = url_ftell(pb);
 469     int num = 0;
 470
 471     while (matroska->num_levels > 0) {
 472         MatroskaLevel *level = &matroska->levels[matroska->num_levels - 1];
 473
 474         if (pos >= level->start + level->length) {
 475             matroska->num_levels--;
 476             num++;
 477         } else {
 478             break;
 479         }
 480     }
 481
 482     return num;
 483 }
 484
 485 /*
 486  * Read: an "EBML number", which is defined as a variable-length
 487  * array of bytes. The first byte indicates the length by giving a
 488  * number of 0-bits followed by a one. The position of the first
 489  * "one" bit inside the first byte indicates the length of this
 490  * number.
 491  * Returns: num. of bytes read. < 0 on error.
 492  */
 493 static int
 494 ebml_read_num (MatroskaDemuxContext *matroska,
 495                int                   max_size,
 496                uint64_t             *number)
 497 {
 498     ByteIOContext *pb = matroska->ctx->pb;
 499     int len_mask = 0x80, read = 1, n = 1;
 500     int64_t total = 0;
 501
 502     /* the first byte tells us the length in bytes - get_byte() can normally
 503      * return 0, but since that's not a valid first ebmlID byte, we can
 504      * use it safely here to catch EOS. */
 505     if (!(total = get_byte(pb))) {
 506         /* we might encounter EOS here */
 507         if (!url_feof(pb)) {
 508             offset_t pos = url_ftell(pb);
 509             av_log(matroska->ctx, AV_LOG_ERROR,
 510                    "Read error at pos. %"PRIu64" (0x%"PRIx64")\n",
 511                    pos, pos);
 512         }
 513         return AVERROR(EIO); /* EOS or actual I/O error */
 514     }
 515
 516     /* get the length of the EBML number */
 517     while (read <= max_size && !(total & len_mask)) {
 518         read++;
 519         len_mask >>= 1;
 520     }
 521     if (read > max_size) {
 522         offset_t pos = url_ftell(pb) - 1;
 523         av_log(matroska->ctx, AV_LOG_ERROR,
 524                "Invalid EBML number size tag 0x%02x at pos %"PRIu64" (0x%"PRIx64")\n",
 525                (uint8_t) total, pos, pos);
 526         return AVERROR_INVALIDDATA;
 527     }
 528
 529     /* read out length */
 530     total &= ~len_mask;
 531     while (n++ < read)
 532         total = (total << 8) | get_byte(pb);
 533
 534     *number = total;
 535
 536     return read;
 537 }
 538
 539 /*
 540  * Read: the element content data ID.
 541  * Return: the number of bytes read or < 0 on error.
 542  */
 543 static int
 544 ebml_read_element_id (MatroskaDemuxContext *matroska,
 545                       uint32_t             *id)
 546 {
 547     int read;
 548     uint64_t total;
 549
 550     /* if we re-call this, use our cached ID */
 551     if (matroska->peek_id != 0) {
 552         *id = matroska->peek_id;
 553         return 0;
 554     }
 555
 556     /* read out the "EBML number", include tag in ID */
 557     if ((read = ebml_read_num(matroska, 4, &total)) < 0)
 558         return read;
 559     *id = matroska->peek_id  = total | (1 << (read * 7));
 560
 561     return read;
 562 }
 563
 564 /*
 565  * Read: element content length.
 566  * Return: the number of bytes read or < 0 on error.
 567  */
 568 static int
 569 ebml_read_element_length (MatroskaDemuxContext *matroska,
 570                           uint64_t             *length)
 571 {
 572     /* clear cache since we're now beyond that data point */
 573     matroska->peek_id = 0;
 574
 575     /* read out the "EBML number", include tag in ID */
 576     return ebml_read_num(matroska, 8, length);
 577 }
 578
 579 /*
 580  * Seek to a given offset.
 581  * 0 is success, -1 is failure.
 582  */
 583 static int
 584 ebml_read_seek (MatroskaDemuxContext *matroska,
 585                 offset_t              offset)
 586 {
 587     ByteIOContext *pb = matroska->ctx->pb;
 588
 589     /* clear ID cache, if any */
 590     matroska->peek_id = 0;
 591
 592     return (url_fseek(pb, offset, SEEK_SET) == offset) ? 0 : -1;
 593 }
 594
 595 /*
 596  * Read the next element as an unsigned int.
 597  * 0 is success, < 0 is failure.
 598  */
 599 static int
 600 ebml_read_uint (ByteIOContext *pb,
 601                 int            size,
 602                 uint64_t             *num)
 603 {
 604     int n = 0;
 605
 606     if (size < 1 || size > 8)
 607         return AVERROR_INVALIDDATA;
 608
 609     /* big-endian ordening; build up number */
 610     *num = 0;
 611     while (n++ < size)
 612         *num = (*num << 8) | get_byte(pb);
 613
 614     return 0;
 615 }
 616
 617 /*
 618  * Read the next element as a float.
 619  * 0 is success, < 0 is failure.
 620  */
 621 static int
 622 ebml_read_float (ByteIOContext *pb,
 623                  int            size,
 624                  double               *num)
 625 {
 626     if (size == 4) {
 627         *num= av_int2flt(get_be32(pb));
 628     } else if(size==8){
 629         *num= av_int2dbl(get_be64(pb));
 630     } else
 631         return AVERROR_INVALIDDATA;
 632
 633     return 0;
 634 }
 635
 636 /*
 637  * Read the next element as an ASCII string.
 638  * 0 is success, < 0 is failure.
 639  */
 640 static int
 641 ebml_read_ascii (ByteIOContext *pb,
 642                  int            size,
 643                  char                **str)
 644 {
 645     av_free(*str);
 646     /* ebml strings are usually not 0-terminated, so we allocate one
 647      * byte more, read the string and NULL-terminate it ourselves. */
 648     if (!(*str = av_malloc(size + 1)))
 649         return AVERROR(ENOMEM);
 650     if (get_buffer(pb, (uint8_t *) *str, size) != size) {
 651         av_free(*str);
 652         return AVERROR(EIO);
 653     }
 654     (*str)[size] = '\0';
 655
 656     return 0;
 657 }
 658
 659 /*
 660  * Read the next element, but only the header. The contents
 661  * are supposed to be sub-elements which can be read separately.
 662  * 0 is success, < 0 is failure.
 663  */
 664 static int
 665 ebml_read_master (MatroskaDemuxContext *matroska,
 666                   int                   length)
 667 {
 668     ByteIOContext *pb = matroska->ctx->pb;
 669     MatroskaLevel *level;
 670
 671     if (matroska->num_levels >= EBML_MAX_DEPTH) {
 672         av_log(matroska->ctx, AV_LOG_ERROR,
 673                "File moves beyond max. allowed depth (%d)\n", EBML_MAX_DEPTH);
 674         return AVERROR(ENOSYS);
 675     }
 676
 677     level = &matroska->levels[matroska->num_levels++];
 678     level->start = url_ftell(pb);
 679     level->length = length;
 680
 681     return 0;
 682 }
 683
 684 /*
 685  * Read the next element as binary data.
 686  * 0 is success, < 0 is failure.
 687  */
 688 static int
 689 ebml_read_binary (ByteIOContext *pb,
 690                   int            length,
 691                   EbmlBin       *bin)
 692 {
 693     av_free(bin->data);
 694     if (!(bin->data = av_malloc(length)))
 695         return AVERROR(ENOMEM);
 696
 697     bin->size = length;
 698     bin->pos  = url_ftell(pb);
 699     if (get_buffer(pb, bin->data, length) != length)
 700         return AVERROR(EIO);
 701
 702     return 0;
 703 }
 704
 705 /*
 706  * Read signed/unsigned "EBML" numbers.
 707  * Return: number of bytes processed, < 0 on error.
 708  * XXX: use ebml_read_num().
 709  */
 710 static int
 711 matroska_ebmlnum_uint (uint8_t  *data,
 712                        uint32_t  size,
 713                        uint64_t *num)
 714 {
 715     int len_mask = 0x80, read = 1, n = 1, num_ffs = 0;
 716     uint64_t total;
 717
 718     if (size <= 0)
 719         return AVERROR_INVALIDDATA;
 720
 721     total = data[0];
 722     while (read <= 8 && !(total & len_mask)) {
 723         read++;
 724         len_mask >>= 1;
 725     }
 726     if (read > 8)
 727         return AVERROR_INVALIDDATA;
 728
 729     if ((total &= (len_mask - 1)) == len_mask - 1)
 730         num_ffs++;
 731     if (size < read)
 732         return AVERROR_INVALIDDATA;
 733     while (n < read) {
 734         if (data[n] == 0xff)
 735             num_ffs++;
 736         total = (total << 8) | data[n];
 737         n++;
 738     }
 739
 740     if (read == num_ffs)
 741         *num = (uint64_t)-1;
 742     else
 743         *num = total;
 744
 745     return read;
 746 }
 747
 748 /*
 749  * Same as above, but signed.
 750  */
 751 static int
 752 matroska_ebmlnum_sint (uint8_t  *data,
 753                        uint32_t  size,
 754                        int64_t  *num)
 755 {
 756     uint64_t unum;
 757     int res;
 758
 759     /* read as unsigned number first */
 760     if ((res = matroska_ebmlnum_uint(data, size, &unum)) < 0)
 761         return res;
 762
 763     /* make signed (weird way) */
 764     if (unum == (uint64_t)-1)
 765         *num = INT64_MAX;
 766     else
 767         *num = unum - ((1LL << ((7 * res) - 1)) - 1);
 768
 769     return res;
 770 }
 771
 772
 773 static MatroskaTrack *
 774 matroska_find_track_by_num (MatroskaDemuxContext *matroska,
 775                             int                   num)
 776 {
 777     MatroskaTrack *tracks = matroska->tracks.elem;
 778     int i;
 779
 780     for (i=0; i < matroska->tracks.nb_elem; i++)
 781         if (tracks[i].num == num)
 782             return &tracks[i];
 783
 784     av_log(matroska->ctx, AV_LOG_ERROR, "Invalid track number %d\n", num);
 785     return NULL;
 786 }
 787
 788
 789 /*
 790  * Put one packet in an application-supplied AVPacket struct.
 791  * Returns 0 on success or -1 on failure.
 792  */
 793 static int
 794 matroska_deliver_packet (MatroskaDemuxContext *matroska,
 795                          AVPacket             *pkt)
 796 {
 797     if (matroska->num_packets > 0) {
 798         memcpy(pkt, matroska->packets[0], sizeof(AVPacket));
 799         av_free(matroska->packets[0]);
 800         if (matroska->num_packets > 1) {
 801             memmove(&matroska->packets[0], &matroska->packets[1],
 802                     (matroska->num_packets - 1) * sizeof(AVPacket *));
 803             matroska->packets =
 804                 av_realloc(matroska->packets, (matroska->num_packets - 1) *
 805                            sizeof(AVPacket *));
 806         } else {
 807             av_freep(&matroska->packets);
 808         }
 809         matroska->num_packets--;
 810         return 0;
 811     }
 812
 813     return -1;
 814 }
 815
 816 /*
 817  * Put a packet into our internal queue. Will be delivered to the
 818  * user/application during the next get_packet() call.
 819  */
 820 static void
 821 matroska_queue_packet (MatroskaDemuxContext *matroska,
 822                        AVPacket             *pkt)
 823 {
 824     matroska->packets =
 825         av_realloc(matroska->packets, (matroska->num_packets + 1) *
 826                    sizeof(AVPacket *));
 827     matroska->packets[matroska->num_packets] = pkt;
 828     matroska->num_packets++;
 829 }
 830
 831 /*
 832  * Free all packets in our internal queue.
 833  */
 834 static void
 835 matroska_clear_queue (MatroskaDemuxContext *matroska)
 836 {
 837     if (matroska->packets) {
 838         int n;
 839         for (n = 0; n < matroska->num_packets; n++) {
 840             av_free_packet(matroska->packets[n]);
 841             av_free(matroska->packets[n]);
 842         }
 843         av_free(matroska->packets);
 844         matroska->packets = NULL;
 845         matroska->num_packets = 0;
 846     }
 847 }
 848
 849
 850 /*
 851  * Autodetecting...
 852  */
 853 static int
 854 matroska_probe (AVProbeData *p)
 855 {
 856     uint64_t total = 0;
 857     int len_mask = 0x80, size = 1, n = 1;
 858     uint8_t probe_data[] = { 'm', 'a', 't', 'r', 'o', 's', 'k', 'a' };
 859
 860     /* ebml header? */
 861     if (AV_RB32(p->buf) != EBML_ID_HEADER)
 862         return 0;
 863
 864     /* length of header */
 865     total = p->buf[4];
 866     while (size <= 8 && !(total & len_mask)) {
 867         size++;
 868         len_mask >>= 1;
 869     }
 870     if (size > 8)
 871       return 0;
 872     total &= (len_mask - 1);
 873     while (n < size)
 874         total = (total << 8) | p->buf[4 + n++];
 875
 876     /* does the probe data contain the whole header? */
 877     if (p->buf_size < 4 + size + total)
 878       return 0;
 879
 880     /* the header must contain the document type 'matroska'. For now,
 881      * we don't parse the whole header but simply check for the
 882      * availability of that array of characters inside the header.
 883      * Not fully fool-proof, but good enough. */
 884     for (n = 4 + size; n <= 4 + size + total - sizeof(probe_data); n++)
 885         if (!memcmp (&p->buf[n], probe_data, sizeof(probe_data)))
 886             return AVPROBE_SCORE_MAX;
 887
 888     return 0;
 889 }
 890
 891 static int ebml_parse(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 892                       void *data, int once);
 893
 894 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
 895                            EbmlSyntax *syntax, void *data)
 896 {
 897     ByteIOContext *pb = matroska->ctx->pb;
 898     uint32_t id = syntax->id;
 899     uint64_t length;
 900     int res;
 901
 902     data = (char *)data + syntax->data_offset;
 903     if (syntax->list_elem_size) {
 904         EbmlList *list = data;
 905         list->elem = av_realloc(list->elem, (list->nb_elem+1)*syntax->list_elem_size);
 906         data = (char*)list->elem + list->nb_elem*syntax->list_elem_size;
 907         memset(data, 0, syntax->list_elem_size);
 908         list->nb_elem++;
 909     }
 910
 911     if (syntax->type != EBML_PASS && syntax->type != EBML_STOP)
 912         if ((res = ebml_read_element_id(matroska, &id)) < 0 ||
 913             (res = ebml_read_element_length(matroska, &length)) < 0)
 914             return res;
 915
 916     switch (syntax->type) {
 917     case EBML_UINT:  res = ebml_read_uint  (pb, length, data);  break;
 918     case EBML_FLOAT: res = ebml_read_float (pb, length, data);  break;
 919     case EBML_STR:
 920     case EBML_UTF8:  res = ebml_read_ascii (pb, length, data);  break;
 921     case EBML_BIN:   res = ebml_read_binary(pb, length, data);  break;
 922     case EBML_NEST:  if ((res=ebml_read_master(matroska, length)) < 0)
 923                          return res;
 924                      if (id == MATROSKA_ID_SEGMENT)
 925                          matroska->segment_start = url_ftell(matroska->ctx->pb);
 926                      return ebml_parse(matroska, syntax->def.n, data, 0);
 927     case EBML_PASS:  return ebml_parse(matroska, syntax->def.n, data, 1);
 928     case EBML_STOP:  *(int *)data = 1;      return 1;
 929     default:         url_fskip(pb, length); return 0;
 930     }
 931     if (res == AVERROR_INVALIDDATA)
 932         av_log(matroska->ctx, AV_LOG_ERROR, "Invalid element\n");
 933     else if (res == AVERROR(EIO))
 934         av_log(matroska->ctx, AV_LOG_ERROR, "Read error\n");
 935     return res;
 936 }
 937
 938 static int ebml_parse_id(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 939                          uint32_t id, void *data)
 940 {
 941     int i;
 942     for (i=0; syntax[i].id; i++)
 943         if (id == syntax[i].id)
 944             break;
 945     if (!syntax[i].id)
 946         av_log(matroska->ctx, AV_LOG_INFO, "Unknown entry 0x%X\n", id);
 947     return ebml_parse_elem(matroska, &syntax[i], data);
 948 }
 949
 950 static int ebml_parse(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 951                       void *data, int once)
 952 {
 953     int i, res = 0, res2;
 954     uint32_t id = 0;
 955
 956     for (i=0; syntax[i].id; i++)
 957         switch (syntax[i].type) {
 958         case EBML_UINT:
 959             *(uint64_t *)((char *)data+syntax[i].data_offset) = syntax[i].def.u;
 960             break;
 961         case EBML_FLOAT:
 962             *(double   *)((char *)data+syntax[i].data_offset) = syntax[i].def.f;
 963             break;
 964         case EBML_STR:
 965         case EBML_UTF8:
 966             *(char    **)((char *)data+syntax[i].data_offset) = av_strdup(syntax[i].def.s);
 967             break;
 968         }
 969
 970     while (!res) {
 971         res2 = ebml_read_element_id(matroska, &id);
 972         if (res2 < 0)
 973             break;
 974         if (res2 > 0)
 975             matroska->level_up = ebml_read_element_level_up(matroska);
 976         if (matroska->level_up) {
 977             matroska->level_up--;
 978             break;
 979         }
 980
 981         res = ebml_parse_id(matroska, syntax, id, data);
 982         if (once)
 983             break;
 984     }
 985
 986     return res;
 987 }
 988
 989 static void ebml_free(EbmlSyntax *syntax, void *data)
 990 {
 991     int i, j;
 992     for (i=0; syntax[i].id; i++) {
 993         void *data_off = (char *)data + syntax[i].data_offset;
 994         switch (syntax[i].type) {
 995         case EBML_STR:
 996         case EBML_UTF8:  av_freep(data_off);                      break;
 997         case EBML_BIN:   av_freep(&((EbmlBin *)data_off)->data);  break;
 998         case EBML_NEST:
 999             if (syntax[i].list_elem_size) {
1000                 EbmlList *list = data_off;
1001                 char *ptr = list->elem;
1002                 for (j=0; j<list->nb_elem; j++, ptr+=syntax[i].list_elem_size)
1003                     ebml_free(syntax[i].def.n, ptr);
1004                 av_free(list->elem);
1005             } else
1006                 ebml_free(syntax[i].def.n, data_off);
1007         default:  break;
1008         }
1009     }
1010 }
1011
1012 static int
1013 matroska_decode_buffer(uint8_t** buf, int* buf_size, MatroskaTrack *track)
1014 {
1015     MatroskaTrackEncoding *encodings = track->encodings.elem;
1016     uint8_t* data = *buf;
1017     int isize = *buf_size;
1018     uint8_t* pkt_data = NULL;
1019     int pkt_size = isize;
1020     int result = 0;
1021     int olen;
1022
1023     switch (encodings[0].compression.algo) {
1024     case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP:
1025         return encodings[0].compression.settings.size;
1026     case MATROSKA_TRACK_ENCODING_COMP_LZO:
1027         do {
1028             olen = pkt_size *= 3;
1029             pkt_data = av_realloc(pkt_data,
1030                                   pkt_size+LZO_OUTPUT_PADDING);
1031             result = lzo1x_decode(pkt_data, &olen, data, &isize);
1032         } while (result==LZO_OUTPUT_FULL && pkt_size<10000000);
1033         if (result)
1034             goto failed;
1035         pkt_size -= olen;
1036         break;
1037 #ifdef CONFIG_ZLIB
1038     case MATROSKA_TRACK_ENCODING_COMP_ZLIB: {
1039         z_stream zstream = {0};
1040         if (inflateInit(&zstream) != Z_OK)
1041             return -1;
1042         zstream.next_in = data;
1043         zstream.avail_in = isize;
1044         do {
1045             pkt_size *= 3;
1046             pkt_data = av_realloc(pkt_data, pkt_size);
1047             zstream.avail_out = pkt_size - zstream.total_out;
1048             zstream.next_out = pkt_data + zstream.total_out;
1049             result = inflate(&zstream, Z_NO_FLUSH);
1050         } while (result==Z_OK && pkt_size<10000000);
1051         pkt_size = zstream.total_out;
1052         inflateEnd(&zstream);
1053         if (result != Z_STREAM_END)
1054             goto failed;
1055         break;
1056     }
1057 #endif
1058 #ifdef CONFIG_BZLIB
1059     case MATROSKA_TRACK_ENCODING_COMP_BZLIB: {
1060         bz_stream bzstream = {0};
1061         if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
1062             return -1;
1063         bzstream.next_in = data;
1064         bzstream.avail_in = isize;
1065         do {
1066             pkt_size *= 3;
1067             pkt_data = av_realloc(pkt_data, pkt_size);
1068             bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
1069             bzstream.next_out = pkt_data + bzstream.total_out_lo32;
1070             result = BZ2_bzDecompress(&bzstream);
1071         } while (result==BZ_OK && pkt_size<10000000);
1072         pkt_size = bzstream.total_out_lo32;
1073         BZ2_bzDecompressEnd(&bzstream);
1074         if (result != BZ_STREAM_END)
1075             goto failed;
1076         break;
1077     }
1078 #endif
1079     }
1080
1081     *buf = pkt_data;
1082     *buf_size = pkt_size;
1083     return 0;
1084  failed:
1085     av_free(pkt_data);
1086     return -1;
1087 }
1088
1089 static void
1090 matroska_execute_seekhead(MatroskaDemuxContext *matroska)
1091 {
1092     EbmlList *seekhead_list = &matroska->seekhead;
1093     MatroskaSeekhead *seekhead = seekhead_list->elem;
1094     uint32_t peek_id_cache = matroska->peek_id;
1095     uint32_t level_up = matroska->level_up;
1096     offset_t before_pos = url_ftell(matroska->ctx->pb);
1097     MatroskaLevel level;
1098     int i;
1099
1100     for (i=0; i<seekhead_list->nb_elem; i++) {
1101         if (seekhead[i].pos <= before_pos
1102             || seekhead[i].id == MATROSKA_ID_SEEKHEAD
1103             || seekhead[i].id == MATROSKA_ID_CLUSTER)
1104             continue;
1105
1106         /* seek */
1107         if (ebml_read_seek(matroska,
1108                            seekhead[i].pos+matroska->segment_start) < 0)
1109             continue;
1110
1111         /* we don't want to lose our seekhead level, so we add
1112          * a dummy. This is a crude hack. */
1113         if (matroska->num_levels == EBML_MAX_DEPTH) {
1114             av_log(matroska->ctx, AV_LOG_INFO,
1115                    "Max EBML element depth (%d) reached, "
1116                    "cannot parse further.\n", EBML_MAX_DEPTH);
1117             break;
1118         }
1119
1120         level.start = 0;
1121         level.length = (uint64_t)-1;
1122         matroska->levels[matroska->num_levels] = level;
1123         matroska->num_levels++;
1124
1125         ebml_parse_id(matroska, matroska_segment, seekhead[i].id, matroska);
1126
1127         /* remove dummy level */
1128         while (matroska->num_levels) {
1129             uint64_t length = matroska->levels[--matroska->num_levels].length;
1130             if (length == (uint64_t)-1)
1131                 break;
1132         }
1133     }
1134
1135     /* seek back */
1136     ebml_read_seek(matroska, before_pos);
1137     matroska->peek_id = peek_id_cache;
1138     matroska->level_up = level_up;
1139 }
1140
1141 static int
1142 matroska_aac_profile (char *codec_id)
1143 {
1144     static const char *aac_profiles[] = { "MAIN", "LC", "SSR" };
1145     int profile;
1146
1147     for (profile=0; profile<ARRAY_SIZE(aac_profiles); profile++)
1148         if (strstr(codec_id, aac_profiles[profile]))
1149             break;
1150     return profile + 1;
1151 }
1152
1153 static int
1154 matroska_aac_sri (int samplerate)
1155 {
1156     int sri;
1157
1158     for (sri=0; sri<ARRAY_SIZE(ff_mpeg4audio_sample_rates); sri++)
1159         if (ff_mpeg4audio_sample_rates[sri] == samplerate)
1160             break;
1161     return sri;
1162 }
1163
1164 static int
1165 matroska_read_header (AVFormatContext    *s,
1166                       AVFormatParameters *ap)
1167 {
1168     MatroskaDemuxContext *matroska = s->priv_data;
1169     EbmlList *attachements_list = &matroska->attachments;
1170     MatroskaAttachement *attachements;
1171     EbmlList *chapters_list = &matroska->chapters;
1172     MatroskaChapter *chapters;
1173     MatroskaTrack *tracks;
1174     EbmlList *index_list;
1175     MatroskaIndex *index;
1176     Ebml ebml = { 0 };
1177     AVStream *st;
1178     int i, j;
1179
1180     matroska->ctx = s;
1181
1182     /* First read the EBML header. */
1183     if (ebml_parse(matroska, ebml_syntax, &ebml, 1)
1184         || ebml.version > EBML_VERSION       || ebml.max_size > sizeof(uint64_t)
1185         || ebml.id_length > sizeof(uint32_t) || strcmp(ebml.doctype, "matroska")
1186         || ebml.doctype_version > 2) {
1187         av_log(matroska->ctx, AV_LOG_ERROR,
1188                "EBML header using unsupported features\n"
1189                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
1190                ebml.version, ebml.doctype, ebml.doctype_version);
1191         return AVERROR_NOFMT;
1192     }
1193     ebml_free(ebml_syntax, &ebml);
1194
1195     /* The next thing is a segment. */
1196     if (ebml_parse(matroska, matroska_segments, matroska, 1) < 0)
1197         return -1;
1198     matroska_execute_seekhead(matroska);
1199
1200     if (matroska->duration)
1201         matroska->ctx->duration = matroska->duration * matroska->time_scale
1202                                   * 1000 / AV_TIME_BASE;
1203     if (matroska->title)
1204         strncpy(matroska->ctx->title, matroska->title,
1205                 sizeof(matroska->ctx->title)-1);
1206
1207     tracks = matroska->tracks.elem;
1208     for (i=0; i < matroska->tracks.nb_elem; i++) {
1209         MatroskaTrack *track = &tracks[i];
1210         enum CodecID codec_id = CODEC_ID_NONE;
1211         EbmlList *encodings_list = &tracks->encodings;
1212         MatroskaTrackEncoding *encodings = encodings_list->elem;
1213         uint8_t *extradata = NULL;
1214         int extradata_size = 0;
1215         int extradata_offset = 0;
1216
1217         /* Apply some sanity checks. */
1218         if (track->type != MATROSKA_TRACK_TYPE_VIDEO &&
1219             track->type != MATROSKA_TRACK_TYPE_AUDIO &&
1220             track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
1221             av_log(matroska->ctx, AV_LOG_INFO,
1222                    "Unknown or unsupported track type %"PRIu64"\n",
1223                    track->type);
1224             continue;
1225         }
1226         if (track->codec_id == NULL)
1227             continue;
1228
1229         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1230             if (!track->default_duration)
1231                 track->default_duration = 1000000000/track->video.frame_rate;
1232             if (!track->video.display_width)
1233                 track->video.display_width = track->video.pixel_width;
1234             if (!track->video.display_height)
1235                 track->video.display_height = track->video.pixel_height;
1236         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1237             if (!track->audio.out_samplerate)
1238                 track->audio.out_samplerate = track->audio.samplerate;
1239         }
1240         if (encodings_list->nb_elem > 1) {
1241             av_log(matroska->ctx, AV_LOG_ERROR,
1242                    "Multiple combined encodings no supported");
1243         } else if (encodings_list->nb_elem == 1) {
1244             if (encodings[0].type ||
1245                 (encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP &&
1246 #ifdef CONFIG_ZLIB
1247                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_ZLIB &&
1248 #endif
1249 #ifdef CONFIG_BZLIB
1250                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_BZLIB &&
1251 #endif
1252                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_LZO)) {
1253                 encodings[0].scope = 0;
1254                 av_log(matroska->ctx, AV_LOG_ERROR,
1255                        "Unsupported encoding type");
1256             } else if (track->codec_priv.size && encodings[0].scope&2) {
1257                 uint8_t *codec_priv = track->codec_priv.data;
1258                 int offset = matroska_decode_buffer(&track->codec_priv.data,
1259                                                     &track->codec_priv.size,
1260                                                     track);
1261                 if (offset < 0) {
1262                     track->codec_priv.data = NULL;
1263                     track->codec_priv.size = 0;
1264                     av_log(matroska->ctx, AV_LOG_ERROR,
1265                            "Failed to decode codec private data\n");
1266                 } else if (offset > 0) {
1267                     track->codec_priv.data = av_malloc(track->codec_priv.size + offset);
1268                     memcpy(track->codec_priv.data,
1269                            encodings[0].compression.settings.data, offset);
1270                     memcpy(track->codec_priv.data+offset, codec_priv,
1271                            track->codec_priv.size);
1272                     track->codec_priv.size += offset;
1273                 }
1274                 if (codec_priv != track->codec_priv.data)
1275                     av_free(codec_priv);
1276             }
1277         }
1278
1279         for(j=0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++){
1280             if(!strncmp(ff_mkv_codec_tags[j].str, track->codec_id,
1281                         strlen(ff_mkv_codec_tags[j].str))){
1282                 codec_id= ff_mkv_codec_tags[j].id;
1283                 break;
1284             }
1285         }
1286
1287         st = track->stream = av_new_stream(s, matroska->num_streams++);
1288         if (st == NULL)
1289             return AVERROR(ENOMEM);
1290
1291         if (!strcmp(track->codec_id, MATROSKA_CODEC_ID_VIDEO_VFW_FOURCC)
1292             && track->codec_priv.size >= 40
1293             && track->codec_priv.data != NULL) {
1294             track->video.fourcc = AV_RL32(track->codec_priv.data + 16);
1295             codec_id = codec_get_id(codec_bmp_tags, track->video.fourcc);
1296         } else if (!strcmp(track->codec_id, MATROSKA_CODEC_ID_AUDIO_ACM)
1297                    && track->codec_priv.size >= 18
1298                    && track->codec_priv.data != NULL) {
1299             uint16_t tag = AV_RL16(track->codec_priv.data);
1300             codec_id = codec_get_id(codec_wav_tags, tag);
1301         } else if (!strcmp(track->codec_id, "V_QUICKTIME")
1302                    && (track->codec_priv.size >= 86)
1303                    && (track->codec_priv.data != NULL)) {
1304             track->video.fourcc = AV_RL32(track->codec_priv.data);
1305             codec_id=codec_get_id(codec_movvideo_tags, track->video.fourcc);
1306         } else if (codec_id == CODEC_ID_AAC && !track->codec_priv.size) {
1307             int profile = matroska_aac_profile(track->codec_id);
1308             int sri = matroska_aac_sri(track->audio.samplerate);
1309             extradata = av_malloc(5);
1310             if (extradata == NULL)
1311                 return AVERROR(ENOMEM);
1312             extradata[0] = (profile << 3) | ((sri&0x0E) >> 1);
1313             extradata[1] = ((sri&0x01) << 7) | (track->audio.channels<<3);
1314             if (strstr(track->codec_id, "SBR")) {
1315                 sri = matroska_aac_sri(track->audio.out_samplerate);
1316                 extradata[2] = 0x56;
1317                 extradata[3] = 0xE5;
1318                 extradata[4] = 0x80 | (sri<<3);
1319                 extradata_size = 5;
1320             } else
1321                 extradata_size = 2;
1322         } else if (codec_id == CODEC_ID_TTA) {
1323             ByteIOContext b;
1324             extradata_size = 30;
1325             extradata = av_mallocz(extradata_size);
1326             if (extradata == NULL)
1327                 return AVERROR(ENOMEM);
1328             init_put_byte(&b, extradata, extradata_size, 1,
1329                           NULL, NULL, NULL, NULL);
1330             put_buffer(&b, "TTA1", 4);
1331             put_le16(&b, 1);
1332             put_le16(&b, track->audio.channels);
1333             put_le16(&b, track->audio.bitdepth);
1334             put_le32(&b, track->audio.out_samplerate);
1335             put_le32(&b, matroska->ctx->duration * track->audio.out_samplerate);
1336         } else if (codec_id == CODEC_ID_RV10 || codec_id == CODEC_ID_RV20 ||
1337                    codec_id == CODEC_ID_RV30 || codec_id == CODEC_ID_RV40) {
1338             extradata_offset = 26;
1339             track->codec_priv.size -= extradata_offset;
1340         } else if (codec_id == CODEC_ID_RA_144) {
1341             track->audio.out_samplerate = 8000;
1342             track->audio.channels = 1;
1343         } else if (codec_id == CODEC_ID_RA_288 || codec_id == CODEC_ID_COOK ||
1344                    codec_id == CODEC_ID_ATRAC3) {
1345             ByteIOContext b;
1346
1347             init_put_byte(&b, track->codec_priv.data,track->codec_priv.size,
1348                           0, NULL, NULL, NULL, NULL);
1349             url_fskip(&b, 24);
1350             track->audio.coded_framesize = get_be32(&b);
1351             url_fskip(&b, 12);
1352             track->audio.sub_packet_h    = get_be16(&b);
1353             track->audio.frame_size      = get_be16(&b);
1354             track->audio.sub_packet_size = get_be16(&b);
1355             track->audio.buf = av_malloc(track->audio.frame_size * track->audio.sub_packet_h);
1356             if (codec_id == CODEC_ID_RA_288) {
1357                 st->codec->block_align = track->audio.coded_framesize;
1358                 track->codec_priv.size = 0;
1359             } else {
1360                 st->codec->block_align = track->audio.sub_packet_size;
1361                 extradata_offset = 78;
1362                 track->codec_priv.size -= extradata_offset;
1363             }
1364         }
1365
1366         if (codec_id == CODEC_ID_NONE)
1367             av_log(matroska->ctx, AV_LOG_INFO,
1368                    "Unknown/unsupported CodecID %s.\n", track->codec_id);
1369
1370         av_set_pts_info(st, 64, matroska->time_scale*track->time_scale, 1000*1000*1000); /* 64 bit pts in ns */
1371
1372         st->codec->codec_id = codec_id;
1373         st->start_time = 0;
1374         if (strcmp(track->language, "und"))
1375             av_strlcpy(st->language, track->language, 4);
1376
1377         if (track->flag_default)
1378             st->disposition |= AV_DISPOSITION_DEFAULT;
1379
1380         if (track->default_duration)
1381             av_reduce(&st->codec->time_base.num, &st->codec->time_base.den,
1382                       track->default_duration, 1000000000, 30000);
1383
1384         if(extradata){
1385             st->codec->extradata = extradata;
1386             st->codec->extradata_size = extradata_size;
1387         } else if(track->codec_priv.data && track->codec_priv.size > 0){
1388             st->codec->extradata = av_malloc(track->codec_priv.size);
1389             if(st->codec->extradata == NULL)
1390                 return AVERROR(ENOMEM);
1391             st->codec->extradata_size = track->codec_priv.size;
1392             memcpy(st->codec->extradata,
1393                    track->codec_priv.data + extradata_offset,
1394                    track->codec_priv.size);
1395         }
1396
1397         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1398             st->codec->codec_type = CODEC_TYPE_VIDEO;
1399             st->codec->codec_tag  = track->video.fourcc;
1400             st->codec->width  = track->video.pixel_width;
1401             st->codec->height = track->video.pixel_height;
1402             av_reduce(&st->codec->sample_aspect_ratio.num,
1403                       &st->codec->sample_aspect_ratio.den,
1404                       st->codec->height * track->video.display_width,
1405                       st->codec-> width * track->video.display_height,
1406                       255);
1407             st->need_parsing = AVSTREAM_PARSE_HEADERS;
1408         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1409             st->codec->codec_type = CODEC_TYPE_AUDIO;
1410             st->codec->sample_rate = track->audio.out_samplerate;
1411             st->codec->channels = track->audio.channels;
1412         } else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
1413             st->codec->codec_type = CODEC_TYPE_SUBTITLE;
1414         }
1415     }
1416
1417     attachements = attachements_list->elem;
1418     for (j=0; j<attachements_list->nb_elem; j++) {
1419         if (!(attachements[j].filename && attachements[j].mime &&
1420               attachements[j].bin.data && attachements[j].bin.size > 0)) {
1421             av_log(matroska->ctx, AV_LOG_ERROR, "incomplete attachment\n");
1422         } else {
1423             AVStream *st = av_new_stream(s, matroska->num_streams++);
1424             if (st == NULL)
1425                 break;
1426             st->filename          = av_strdup(attachements[j].filename);
1427             st->codec->codec_id = CODEC_ID_NONE;
1428             st->codec->codec_type = CODEC_TYPE_ATTACHMENT;
1429             st->codec->extradata  = av_malloc(attachements[j].bin.size);
1430             if(st->codec->extradata == NULL)
1431                 break;
1432             st->codec->extradata_size = attachements[j].bin.size;
1433             memcpy(st->codec->extradata, attachements[j].bin.data, attachements[j].bin.size);
1434
1435             for (i=0; ff_mkv_mime_tags[i].id != CODEC_ID_NONE; i++) {
1436                 if (!strncmp(ff_mkv_mime_tags[i].str, attachements[j].mime,
1437                              strlen(ff_mkv_mime_tags[i].str))) {
1438                     st->codec->codec_id = ff_mkv_mime_tags[i].id;
1439                     break;
1440                 }
1441             }
1442         }
1443     }
1444
1445     chapters = chapters_list->elem;
1446     for (i=0; i<chapters_list->nb_elem; i++)
1447         if (chapters[i].start != AV_NOPTS_VALUE && chapters[i].uid)
1448             ff_new_chapter(s, chapters[i].uid, (AVRational){1, 1000000000},
1449                            chapters[i].start, chapters[i].end,
1450                            chapters[i].title);
1451
1452     index_list = &matroska->index;
1453     index = index_list->elem;
1454     for (i=0; i<index_list->nb_elem; i++) {
1455         EbmlList *pos_list = &index[i].pos;
1456         MatroskaIndexPos *pos = pos_list->elem;
1457         for (j=0; j<pos_list->nb_elem; j++) {
1458             MatroskaTrack *track = matroska_find_track_by_num(matroska,
1459                                                               pos[j].track);
1460             if (track && track->stream)
1461                 av_add_index_entry(track->stream,
1462                                    pos[j].pos + matroska->segment_start,
1463                                    index[i].time*matroska->time_scale/AV_TIME_BASE,
1464                                    0, 0, AVINDEX_KEYFRAME);
1465         }
1466     }
1467
1468     return 0;
1469 }
1470
1471 static int
1472 matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data, int size,
1473                      int64_t pos, uint64_t cluster_time, uint64_t duration,
1474                      int is_keyframe)
1475 {
1476     MatroskaTrack *track;
1477     int res = 0;
1478     AVStream *st;
1479     AVPacket *pkt;
1480     int16_t block_time;
1481     uint32_t *lace_size = NULL;
1482     int n, flags, laces = 0;
1483     uint64_t num;
1484
1485     if ((n = matroska_ebmlnum_uint(data, size, &num)) < 0) {
1486         av_log(matroska->ctx, AV_LOG_ERROR, "EBML block data error\n");
1487         return res;
1488     }
1489     data += n;
1490     size -= n;
1491
1492     track = matroska_find_track_by_num(matroska, num);
1493     if (size <= 3 || !track || !track->stream) {
1494         av_log(matroska->ctx, AV_LOG_INFO,
1495                "Invalid stream %"PRIu64" or size %u\n", num, size);
1496         return res;
1497     }
1498     st = track->stream;
1499     if (st->discard >= AVDISCARD_ALL)
1500         return res;
1501     if (duration == AV_NOPTS_VALUE)
1502         duration = track->default_duration / matroska->time_scale;
1503
1504     block_time = AV_RB16(data);
1505     data += 2;
1506     flags = *data++;
1507     size -= 3;
1508     if (is_keyframe == -1)
1509         is_keyframe = flags & 0x80 ? PKT_FLAG_KEY : 0;
1510
1511     if (matroska->skip_to_keyframe) {
1512         if (!is_keyframe || st != matroska->skip_to_stream)
1513             return res;
1514         matroska->skip_to_keyframe = 0;
1515     }
1516
1517     switch ((flags & 0x06) >> 1) {
1518         case 0x0: /* no lacing */
1519             laces = 1;
1520             lace_size = av_mallocz(sizeof(int));
1521             lace_size[0] = size;
1522             break;
1523
1524         case 0x1: /* xiph lacing */
1525         case 0x2: /* fixed-size lacing */
1526         case 0x3: /* EBML lacing */
1527             assert(size>0); // size <=3 is checked before size-=3 above
1528             laces = (*data) + 1;
1529             data += 1;
1530             size -= 1;
1531             lace_size = av_mallocz(laces * sizeof(int));
1532
1533             switch ((flags & 0x06) >> 1) {
1534                 case 0x1: /* xiph lacing */ {
1535                     uint8_t temp;
1536                     uint32_t total = 0;
1537                     for (n = 0; res == 0 && n < laces - 1; n++) {
1538                         while (1) {
1539                             if (size == 0) {
1540                                 res = -1;
1541                                 break;
1542                             }
1543                             temp = *data;
1544                             lace_size[n] += temp;
1545                             data += 1;
1546                             size -= 1;
1547                             if (temp != 0xff)
1548                                 break;
1549                         }
1550                         total += lace_size[n];
1551                     }
1552                     lace_size[n] = size - total;
1553                     break;
1554                 }
1555
1556                 case 0x2: /* fixed-size lacing */
1557                     for (n = 0; n < laces; n++)
1558                         lace_size[n] = size / laces;
1559                     break;
1560
1561                 case 0x3: /* EBML lacing */ {
1562                     uint32_t total;
1563                     n = matroska_ebmlnum_uint(data, size, &num);
1564                     if (n < 0) {
1565                         av_log(matroska->ctx, AV_LOG_INFO,
1566                                "EBML block data error\n");
1567                         break;
1568                     }
1569                     data += n;
1570                     size -= n;
1571                     total = lace_size[0] = num;
1572                     for (n = 1; res == 0 && n < laces - 1; n++) {
1573                         int64_t snum;
1574                         int r;
1575                         r = matroska_ebmlnum_sint (data, size, &snum);
1576                         if (r < 0) {
1577                             av_log(matroska->ctx, AV_LOG_INFO,
1578                                    "EBML block data error\n");
1579                             break;
1580                         }
1581                         data += r;
1582                         size -= r;
1583                         lace_size[n] = lace_size[n - 1] + snum;
1584                         total += lace_size[n];
1585                     }
1586                     lace_size[n] = size - total;
1587                     break;
1588                 }
1589             }
1590             break;
1591     }
1592
1593     if (res == 0) {
1594         uint64_t timecode = AV_NOPTS_VALUE;
1595
1596         if (cluster_time != (uint64_t)-1
1597             && (block_time >= 0 || cluster_time >= -block_time))
1598             timecode = cluster_time + block_time;
1599
1600         for (n = 0; n < laces; n++) {
1601             if (st->codec->codec_id == CODEC_ID_RA_288 ||
1602                 st->codec->codec_id == CODEC_ID_COOK ||
1603                 st->codec->codec_id == CODEC_ID_ATRAC3) {
1604                 int a = st->codec->block_align;
1605                 int sps = track->audio.sub_packet_size;
1606                 int cfs = track->audio.coded_framesize;
1607                 int h = track->audio.sub_packet_h;
1608                 int y = track->audio.sub_packet_cnt;
1609                 int w = track->audio.frame_size;
1610                 int x;
1611
1612                 if (!track->audio.pkt_cnt) {
1613                     if (st->codec->codec_id == CODEC_ID_RA_288)
1614                         for (x=0; x<h/2; x++)
1615                             memcpy(track->audio.buf+x*2*w+y*cfs,
1616                                    data+x*cfs, cfs);
1617                     else
1618                         for (x=0; x<w/sps; x++)
1619                             memcpy(track->audio.buf+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), data+x*sps, sps);
1620
1621                     if (++track->audio.sub_packet_cnt >= h) {
1622                         track->audio.sub_packet_cnt = 0;
1623                         track->audio.pkt_cnt = h*w / a;
1624                     }
1625                 }
1626                 while (track->audio.pkt_cnt) {
1627                     pkt = av_mallocz(sizeof(AVPacket));
1628                     av_new_packet(pkt, a);
1629                     memcpy(pkt->data, track->audio.buf
1630                            + a * (h*w / a - track->audio.pkt_cnt--), a);
1631                     pkt->pos = pos;
1632                     pkt->stream_index = st->index;
1633                     matroska_queue_packet(matroska, pkt);
1634                 }
1635             } else {
1636                 MatroskaTrackEncoding *encodings = track->encodings.elem;
1637                 int offset = 0, pkt_size = lace_size[n];
1638                 uint8_t *pkt_data = data;
1639
1640                 if (encodings && encodings->scope & 1) {
1641                     offset = matroska_decode_buffer(&pkt_data,&pkt_size, track);
1642                     if (offset < 0)
1643                         continue;
1644                 }
1645
1646                 pkt = av_mallocz(sizeof(AVPacket));
1647                 /* XXX: prevent data copy... */
1648                 if (av_new_packet(pkt, pkt_size+offset) < 0) {
1649                     av_free(pkt);
1650                     res = AVERROR(ENOMEM);
1651                     n = laces-1;
1652                     break;
1653                 }
1654                 if (offset)
1655                     memcpy (pkt->data, encodings->compression.settings.data, offset);
1656                 memcpy (pkt->data+offset, pkt_data, pkt_size);
1657
1658                 if (pkt_data != data)
1659                     av_free(pkt_data);
1660
1661                 if (n == 0)
1662                     pkt->flags = is_keyframe;
1663                 pkt->stream_index = st->index;
1664
1665                 pkt->pts = timecode;
1666                 pkt->pos = pos;
1667                 pkt->duration = duration;
1668
1669                 matroska_queue_packet(matroska, pkt);
1670             }
1671
1672             if (timecode != AV_NOPTS_VALUE)
1673                 timecode = duration ? timecode + duration : AV_NOPTS_VALUE;
1674             data += lace_size[n];
1675         }
1676     }
1677
1678     av_free(lace_size);
1679     return res;
1680 }
1681
1682 static int
1683 matroska_parse_cluster (MatroskaDemuxContext *matroska)
1684 {
1685     MatroskaCluster cluster = { 0 };
1686     EbmlList *blocks_list;
1687     MatroskaBlock *blocks;
1688     int i, res = ebml_parse(matroska, matroska_clusters, &cluster, 1);
1689     blocks_list = &cluster.blocks;
1690     blocks = blocks_list->elem;
1691     for (i=0; !res && i<blocks_list->nb_elem; i++)
1692         if (blocks[i].bin.size > 0)
1693             res=matroska_parse_block(matroska,
1694                                      blocks[i].bin.data, blocks[i].bin.size,
1695                                      blocks[i].bin.pos,  cluster.timecode,
1696                                      blocks[i].duration, !blocks[i].reference);
1697     ebml_free(matroska_cluster, &cluster);
1698     return res;
1699 }
1700
1701 static int
1702 matroska_read_packet (AVFormatContext *s,
1703                       AVPacket        *pkt)
1704 {
1705     MatroskaDemuxContext *matroska = s->priv_data;
1706
1707     while (matroska_deliver_packet(matroska, pkt)) {
1708         if (matroska->done)
1709             return AVERROR(EIO);
1710         if (matroska_parse_cluster(matroska) < 0)
1711             matroska->done = 1;
1712     }
1713
1714     return 0;
1715 }
1716
1717 static int
1718 matroska_read_seek (AVFormatContext *s, int stream_index, int64_t timestamp,
1719                     int flags)
1720 {
1721     MatroskaDemuxContext *matroska = s->priv_data;
1722     AVStream *st = s->streams[stream_index];
1723     int index;
1724
1725     index = av_index_search_timestamp(st, timestamp, flags);
1726     if (index < 0)
1727         return 0;
1728
1729     matroska_clear_queue(matroska);
1730
1731     url_fseek(s->pb, st->index_entries[index].pos, SEEK_SET);
1732     matroska->skip_to_keyframe = !(flags & AVSEEK_FLAG_ANY);
1733     matroska->skip_to_stream = st;
1734     matroska->peek_id = 0;
1735     av_update_cur_dts(s, st, st->index_entries[index].timestamp);
1736     return 0;
1737 }
1738
1739 static int
1740 matroska_read_close (AVFormatContext *s)
1741 {
1742     MatroskaDemuxContext *matroska = s->priv_data;
1743     MatroskaTrack *tracks = matroska->tracks.elem;
1744     int n;
1745
1746     matroska_clear_queue(matroska);
1747
1748     for (n=0; n < matroska->tracks.nb_elem; n++)
1749         if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)
1750             av_free(tracks[n].audio.buf);
1751     ebml_free(matroska_segment, matroska);
1752
1753     return 0;
1754 }
1755
1756 AVInputFormat matroska_demuxer = {
1757     "matroska",
1758     NULL_IF_CONFIG_SMALL("Matroska file format"),
1759     sizeof(MatroskaDemuxContext),
1760     matroska_probe,
1761     matroska_read_header,
1762     matroska_read_packet,
1763     matroska_read_close,
1764     matroska_read_seek,
1765 };