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 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  * totally reworked by Aurelien Jacobs <aurel@gnuage.org>
  28  * Specs available on the Matroska project page: http://www.matroska.org/.
  29  */
  30
  31 #include <stdio.h>
  32 #include "avformat.h"
  33 /* For codec_get_id(). */
  34 #include "riff.h"
  35 #include "isom.h"
  36 #include "matroska.h"
  37 #include "libavcodec/mpeg4audio.h"
  38 #include "libavutil/intfloat_readwrite.h"
  39 #include "libavutil/avstring.h"
  40 #include "libavutil/lzo.h"
  41 #ifdef CONFIG_ZLIB
  42 #include <zlib.h>
  43 #endif
  44 #ifdef CONFIG_BZLIB
  45 #include <bzlib.h>
  46 #endif
  47
  48 typedef enum {
  49     EBML_NONE,
  50     EBML_UINT,
  51     EBML_FLOAT,
  52     EBML_STR,
  53     EBML_UTF8,
  54     EBML_BIN,
  55     EBML_NEST,
  56     EBML_PASS,
  57     EBML_STOP,
  58 } EbmlType;
  59
  60 typedef const struct EbmlSyntax {
  61     uint32_t id;
  62     EbmlType type;
  63     int list_elem_size;
  64     int data_offset;
  65     union {
  66         uint64_t    u;
  67         double      f;
  68         const char *s;
  69         const struct EbmlSyntax *n;
  70     } def;
  71 } EbmlSyntax;
  72
  73 typedef struct {
  74     int nb_elem;
  75     void *elem;
  76 } EbmlList;
  77
  78 typedef struct {
  79     int      size;
  80     uint8_t *data;
  81     int64_t  pos;
  82 } EbmlBin;
  83
  84 typedef struct {
  85     uint64_t version;
  86     uint64_t max_size;
  87     uint64_t id_length;
  88     char    *doctype;
  89     uint64_t doctype_version;
  90 } Ebml;
  91
  92 typedef struct {
  93     uint64_t algo;
  94     EbmlBin  settings;
  95 } MatroskaTrackCompression;
  96
  97 typedef struct {
  98     uint64_t scope;
  99     uint64_t type;
 100     MatroskaTrackCompression compression;
 101 } MatroskaTrackEncoding;
 102
 103 typedef struct {
 104     double   frame_rate;
 105     uint64_t display_width;
 106     uint64_t display_height;
 107     uint64_t pixel_width;
 108     uint64_t pixel_height;
 109     uint64_t fourcc;
 110 } MatroskaTrackVideo;
 111
 112 typedef struct {
 113     double   samplerate;
 114     double   out_samplerate;
 115     uint64_t bitdepth;
 116     uint64_t channels;
 117
 118     /* real audio header (extracted from extradata) */
 119     int      coded_framesize;
 120     int      sub_packet_h;
 121     int      frame_size;
 122     int      sub_packet_size;
 123     int      sub_packet_cnt;
 124     int      pkt_cnt;
 125     uint8_t *buf;
 126 } MatroskaTrackAudio;
 127
 128 typedef struct {
 129     uint64_t num;
 130     uint64_t type;
 131     char    *codec_id;
 132     EbmlBin  codec_priv;
 133     char    *language;
 134     double time_scale;
 135     uint64_t default_duration;
 136     uint64_t flag_default;
 137     MatroskaTrackVideo video;
 138     MatroskaTrackAudio audio;
 139     EbmlList encodings;
 140
 141     AVStream *stream;
 142     int64_t end_timecode;
 143 } MatroskaTrack;
 144
 145 typedef struct {
 146     char *filename;
 147     char *mime;
 148     EbmlBin bin;
 149 } MatroskaAttachement;
 150
 151 typedef struct {
 152     uint64_t start;
 153     uint64_t end;
 154     uint64_t uid;
 155     char    *title;
 156 } MatroskaChapter;
 157
 158 typedef struct {
 159     uint64_t track;
 160     uint64_t pos;
 161 } MatroskaIndexPos;
 162
 163 typedef struct {
 164     uint64_t time;
 165     EbmlList pos;
 166 } MatroskaIndex;
 167
 168 typedef struct {
 169     char *name;
 170     char *string;
 171     EbmlList sub;
 172 } MatroskaTag;
 173
 174 typedef struct {
 175     uint64_t id;
 176     uint64_t pos;
 177 } MatroskaSeekhead;
 178
 179 typedef struct {
 180     uint64_t start;
 181     uint64_t length;
 182 } MatroskaLevel;
 183
 184 typedef struct {
 185     AVFormatContext *ctx;
 186
 187     /* EBML stuff */
 188     int num_levels;
 189     MatroskaLevel levels[EBML_MAX_DEPTH];
 190     int level_up;
 191
 192     uint64_t time_scale;
 193     double   duration;
 194     char    *title;
 195     EbmlList tracks;
 196     EbmlList attachments;
 197     EbmlList chapters;
 198     EbmlList index;
 199     EbmlList tags;
 200     EbmlList seekhead;
 201
 202     /* byte position of the segment inside the stream */
 203     int64_t segment_start;
 204
 205     /* the packet queue */
 206     AVPacket **packets;
 207     int num_packets;
 208     AVPacket *prev_pkt;
 209
 210     int done;
 211     int has_cluster_id;
 212
 213     /* What to skip before effectively reading a packet. */
 214     int skip_to_keyframe;
 215     uint64_t skip_to_timecode;
 216 } MatroskaDemuxContext;
 217
 218 typedef struct {
 219     uint64_t duration;
 220     int64_t  reference;
 221     EbmlBin  bin;
 222 } MatroskaBlock;
 223
 224 typedef struct {
 225     uint64_t timecode;
 226     EbmlList blocks;
 227 } MatroskaCluster;
 228
 229 static EbmlSyntax ebml_header[] = {
 230     { EBML_ID_EBMLREADVERSION,        EBML_UINT, 0, offsetof(Ebml,version), {.u=EBML_VERSION} },
 231     { EBML_ID_EBMLMAXSIZELENGTH,      EBML_UINT, 0, offsetof(Ebml,max_size), {.u=8} },
 232     { EBML_ID_EBMLMAXIDLENGTH,        EBML_UINT, 0, offsetof(Ebml,id_length), {.u=4} },
 233     { EBML_ID_DOCTYPE,                EBML_STR,  0, offsetof(Ebml,doctype), {.s="(none)"} },
 234     { EBML_ID_DOCTYPEREADVERSION,     EBML_UINT, 0, offsetof(Ebml,doctype_version), {.u=1} },
 235     { EBML_ID_EBMLVERSION,            EBML_NONE },
 236     { EBML_ID_DOCTYPEVERSION,         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     { 0 }
 254 };
 255
 256 static EbmlSyntax matroska_track_video[] = {
 257     { MATROSKA_ID_VIDEOFRAMERATE,     EBML_FLOAT,0, offsetof(MatroskaTrackVideo,frame_rate) },
 258     { MATROSKA_ID_VIDEODISPLAYWIDTH,  EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_width) },
 259     { MATROSKA_ID_VIDEODISPLAYHEIGHT, EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_height) },
 260     { MATROSKA_ID_VIDEOPIXELWIDTH,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_width) },
 261     { MATROSKA_ID_VIDEOPIXELHEIGHT,   EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_height) },
 262     { MATROSKA_ID_VIDEOCOLORSPACE,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,fourcc) },
 263     { MATROSKA_ID_VIDEOPIXELCROPB,    EBML_NONE },
 264     { MATROSKA_ID_VIDEOPIXELCROPT,    EBML_NONE },
 265     { MATROSKA_ID_VIDEOPIXELCROPL,    EBML_NONE },
 266     { MATROSKA_ID_VIDEOPIXELCROPR,    EBML_NONE },
 267     { MATROSKA_ID_VIDEODISPLAYUNIT,   EBML_NONE },
 268     { MATROSKA_ID_VIDEOFLAGINTERLACED,EBML_NONE },
 269     { MATROSKA_ID_VIDEOSTEREOMODE,    EBML_NONE },
 270     { MATROSKA_ID_VIDEOASPECTRATIO,   EBML_NONE },
 271     { 0 }
 272 };
 273
 274 static EbmlSyntax matroska_track_audio[] = {
 275     { MATROSKA_ID_AUDIOSAMPLINGFREQ,  EBML_FLOAT,0, offsetof(MatroskaTrackAudio,samplerate), {.f=8000.0} },
 276     { MATROSKA_ID_AUDIOOUTSAMPLINGFREQ,EBML_FLOAT,0,offsetof(MatroskaTrackAudio,out_samplerate) },
 277     { MATROSKA_ID_AUDIOBITDEPTH,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,bitdepth) },
 278     { MATROSKA_ID_AUDIOCHANNELS,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,channels), {.u=1} },
 279     { 0 }
 280 };
 281
 282 static EbmlSyntax matroska_track_encoding_compression[] = {
 283     { MATROSKA_ID_ENCODINGCOMPALGO,   EBML_UINT, 0, offsetof(MatroskaTrackCompression,algo), {.u=0} },
 284     { MATROSKA_ID_ENCODINGCOMPSETTINGS,EBML_BIN, 0, offsetof(MatroskaTrackCompression,settings) },
 285     { 0 }
 286 };
 287
 288 static EbmlSyntax matroska_track_encoding[] = {
 289     { MATROSKA_ID_ENCODINGSCOPE,      EBML_UINT, 0, offsetof(MatroskaTrackEncoding,scope), {.u=1} },
 290     { MATROSKA_ID_ENCODINGTYPE,       EBML_UINT, 0, offsetof(MatroskaTrackEncoding,type), {.u=0} },
 291     { MATROSKA_ID_ENCODINGCOMPRESSION,EBML_NEST, 0, offsetof(MatroskaTrackEncoding,compression), {.n=matroska_track_encoding_compression} },
 292     { MATROSKA_ID_ENCODINGORDER,      EBML_NONE },
 293     { 0 }
 294 };
 295
 296 static EbmlSyntax matroska_track_encodings[] = {
 297     { MATROSKA_ID_TRACKCONTENTENCODING, EBML_NEST, sizeof(MatroskaTrackEncoding), offsetof(MatroskaTrack,encodings), {.n=matroska_track_encoding} },
 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     { MATROSKA_ID_TRACKMAXBLKADDID,     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     { 0 }
 331 };
 332
 333 static EbmlSyntax matroska_attachment[] = {
 334     { MATROSKA_ID_FILENAME,           EBML_UTF8, 0, offsetof(MatroskaAttachement,filename) },
 335     { MATROSKA_ID_FILEMIMETYPE,       EBML_STR,  0, offsetof(MatroskaAttachement,mime) },
 336     { MATROSKA_ID_FILEDATA,           EBML_BIN,  0, offsetof(MatroskaAttachement,bin) },
 337     { MATROSKA_ID_FILEDESC,           EBML_NONE },
 338     { MATROSKA_ID_FILEUID,            EBML_NONE },
 339     { 0 }
 340 };
 341
 342 static EbmlSyntax matroska_attachments[] = {
 343     { MATROSKA_ID_ATTACHEDFILE,       EBML_NEST, sizeof(MatroskaAttachement), offsetof(MatroskaDemuxContext,attachments), {.n=matroska_attachment} },
 344     { 0 }
 345 };
 346
 347 static EbmlSyntax matroska_chapter_display[] = {
 348     { MATROSKA_ID_CHAPSTRING,         EBML_UTF8, 0, offsetof(MatroskaChapter,title) },
 349     { MATROSKA_ID_CHAPLANG,           EBML_NONE },
 350     { 0 }
 351 };
 352
 353 static EbmlSyntax matroska_chapter_entry[] = {
 354     { MATROSKA_ID_CHAPTERTIMESTART,   EBML_UINT, 0, offsetof(MatroskaChapter,start), {.u=AV_NOPTS_VALUE} },
 355     { MATROSKA_ID_CHAPTERTIMEEND,     EBML_UINT, 0, offsetof(MatroskaChapter,end), {.u=AV_NOPTS_VALUE} },
 356     { MATROSKA_ID_CHAPTERUID,         EBML_UINT, 0, offsetof(MatroskaChapter,uid) },
 357     { MATROSKA_ID_CHAPTERDISPLAY,     EBML_NEST, 0, 0, {.n=matroska_chapter_display} },
 358     { MATROSKA_ID_CHAPTERFLAGHIDDEN,  EBML_NONE },
 359     { MATROSKA_ID_CHAPTERFLAGENABLED, EBML_NONE },
 360     { MATROSKA_ID_CHAPTERPHYSEQUIV,   EBML_NONE },
 361     { MATROSKA_ID_CHAPTERATOM,        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     { MATROSKA_ID_EDITIONFLAGORDERED, EBML_NONE },
 371     { 0 }
 372 };
 373
 374 static EbmlSyntax matroska_chapters[] = {
 375     { MATROSKA_ID_EDITIONENTRY,       EBML_NEST, 0, 0, {.n=matroska_chapter} },
 376     { 0 }
 377 };
 378
 379 static EbmlSyntax matroska_index_pos[] = {
 380     { MATROSKA_ID_CUETRACK,           EBML_UINT, 0, offsetof(MatroskaIndexPos,track) },
 381     { MATROSKA_ID_CUECLUSTERPOSITION, EBML_UINT, 0, offsetof(MatroskaIndexPos,pos)   },
 382     { MATROSKA_ID_CUEBLOCKNUMBER,     EBML_NONE },
 383     { 0 }
 384 };
 385
 386 static EbmlSyntax matroska_index_entry[] = {
 387     { MATROSKA_ID_CUETIME,            EBML_UINT, 0, offsetof(MatroskaIndex,time) },
 388     { MATROSKA_ID_CUETRACKPOSITION,   EBML_NEST, sizeof(MatroskaIndexPos), offsetof(MatroskaIndex,pos), {.n=matroska_index_pos} },
 389     { 0 }
 390 };
 391
 392 static EbmlSyntax matroska_index[] = {
 393     { MATROSKA_ID_POINTENTRY,         EBML_NEST, sizeof(MatroskaIndex), offsetof(MatroskaDemuxContext,index), {.n=matroska_index_entry} },
 394     { 0 }
 395 };
 396
 397 static EbmlSyntax matroska_simpletag[] = {
 398     { MATROSKA_ID_TAGNAME,            EBML_UTF8, 0, offsetof(MatroskaTag,name) },
 399     { MATROSKA_ID_TAGSTRING,          EBML_UTF8, 0, offsetof(MatroskaTag,string) },
 400     { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTag,sub), {.n=matroska_simpletag} },
 401     { MATROSKA_ID_TAGLANG,            EBML_NONE },
 402     { MATROSKA_ID_TAGDEFAULT,         EBML_NONE },
 403     { 0 }
 404 };
 405
 406 static EbmlSyntax matroska_tag[] = {
 407     { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), 0, {.n=matroska_simpletag} },
 408     { MATROSKA_ID_TAGTARGETS,         EBML_NONE },
 409     { 0 }
 410 };
 411
 412 static EbmlSyntax matroska_tags[] = {
 413     { MATROSKA_ID_TAG,                EBML_NEST, 0, offsetof(MatroskaDemuxContext,tags), {.n=matroska_tag} },
 414     { 0 }
 415 };
 416
 417 static EbmlSyntax matroska_seekhead_entry[] = {
 418     { MATROSKA_ID_SEEKID,             EBML_UINT, 0, offsetof(MatroskaSeekhead,id) },
 419     { MATROSKA_ID_SEEKPOSITION,       EBML_UINT, 0, offsetof(MatroskaSeekhead,pos), {.u=-1} },
 420     { 0 }
 421 };
 422
 423 static EbmlSyntax matroska_seekhead[] = {
 424     { MATROSKA_ID_SEEKENTRY,          EBML_NEST, sizeof(MatroskaSeekhead), offsetof(MatroskaDemuxContext,seekhead), {.n=matroska_seekhead_entry} },
 425     { 0 }
 426 };
 427
 428 static EbmlSyntax matroska_segment[] = {
 429     { MATROSKA_ID_INFO,           EBML_NEST, 0, 0, {.n=matroska_info       } },
 430     { MATROSKA_ID_TRACKS,         EBML_NEST, 0, 0, {.n=matroska_tracks     } },
 431     { MATROSKA_ID_ATTACHMENTS,    EBML_NEST, 0, 0, {.n=matroska_attachments} },
 432     { MATROSKA_ID_CHAPTERS,       EBML_NEST, 0, 0, {.n=matroska_chapters   } },
 433     { MATROSKA_ID_CUES,           EBML_NEST, 0, 0, {.n=matroska_index      } },
 434     { MATROSKA_ID_TAGS,           EBML_NEST, 0, 0, {.n=matroska_tags       } },
 435     { MATROSKA_ID_SEEKHEAD,       EBML_NEST, 0, 0, {.n=matroska_seekhead   } },
 436     { MATROSKA_ID_CLUSTER,        EBML_STOP, 0, offsetof(MatroskaDemuxContext,has_cluster_id) },
 437     { 0 }
 438 };
 439
 440 static EbmlSyntax matroska_segments[] = {
 441     { MATROSKA_ID_SEGMENT,        EBML_NEST, 0, 0, {.n=matroska_segment    } },
 442     { 0 }
 443 };
 444
 445 static EbmlSyntax matroska_blockgroup[] = {
 446     { MATROSKA_ID_BLOCK,          EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
 447     { MATROSKA_ID_SIMPLEBLOCK,    EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
 448     { MATROSKA_ID_BLOCKDURATION,  EBML_UINT, 0, offsetof(MatroskaBlock,duration), {.u=AV_NOPTS_VALUE} },
 449     { MATROSKA_ID_BLOCKREFERENCE, EBML_UINT, 0, offsetof(MatroskaBlock,reference) },
 450     { 0 }
 451 };
 452
 453 static EbmlSyntax matroska_cluster[] = {
 454     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
 455     { MATROSKA_ID_BLOCKGROUP,     EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 456     { MATROSKA_ID_SIMPLEBLOCK,    EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
 457     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
 458     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
 459     { 0 }
 460 };
 461
 462 static EbmlSyntax matroska_clusters[] = {
 463     { MATROSKA_ID_CLUSTER,        EBML_NEST, 0, 0, {.n=matroska_cluster} },
 464     { MATROSKA_ID_INFO,           EBML_NONE },
 465     { MATROSKA_ID_CUES,           EBML_NONE },
 466     { MATROSKA_ID_TAGS,           EBML_NONE },
 467     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
 468     { 0 }
 469 };
 470
 471 #define SIZE_OFF(x) sizeof(((AVFormatContext*)0)->x),offsetof(AVFormatContext,x)
 472 const struct {
 473     const char name[16];
 474     int   size;
 475     int   offset;
 476 } metadata[] = {
 477     { "TITLE",           SIZE_OFF(title)      },
 478     { "ARTIST",          SIZE_OFF(author)     },
 479     { "WRITTEN_BY",      SIZE_OFF(author)     },
 480     { "LEAD_PERFORMER",  SIZE_OFF(author)     },
 481     { "COPYRIGHT",       SIZE_OFF(copyright)  },
 482     { "COMMENT",         SIZE_OFF(comment)    },
 483     { "ALBUM",           SIZE_OFF(album)      },
 484     { "DATE_WRITTEN",    SIZE_OFF(year)       },
 485     { "DATE_RELEASED",   SIZE_OFF(year)       },
 486     { "PART_NUMBER",     SIZE_OFF(track)      },
 487     { "GENRE",           SIZE_OFF(genre)      },
 488 };
 489
 490 /*
 491  * Return: Whether we reached the end of a level in the hierarchy or not.
 492  */
 493 static int ebml_level_end(MatroskaDemuxContext *matroska)
 494 {
 495     ByteIOContext *pb = matroska->ctx->pb;
 496     int64_t pos = url_ftell(pb);
 497
 498     if (matroska->num_levels > 0) {
 499         MatroskaLevel *level = &matroska->levels[matroska->num_levels - 1];
 500         if (pos - level->start >= level->length) {
 501             matroska->num_levels--;
 502             return 1;
 503         }
 504     }
 505     return 0;
 506 }
 507
 508 /*
 509  * Read: an "EBML number", which is defined as a variable-length
 510  * array of bytes. The first byte indicates the length by giving a
 511  * number of 0-bits followed by a one. The position of the first
 512  * "one" bit inside the first byte indicates the length of this
 513  * number.
 514  * Returns: number of bytes read, < 0 on error
 515  */
 516 static int ebml_read_num(MatroskaDemuxContext *matroska, ByteIOContext *pb,
 517                          int max_size, uint64_t *number)
 518 {
 519     int len_mask = 0x80, read = 1, n = 1;
 520     int64_t total = 0;
 521
 522     /* The first byte tells us the length in bytes - get_byte() can normally
 523      * return 0, but since that's not a valid first ebmlID byte, we can
 524      * use it safely here to catch EOS. */
 525     if (!(total = get_byte(pb))) {
 526         /* we might encounter EOS here */
 527         if (!url_feof(pb)) {
 528             int64_t pos = url_ftell(pb);
 529             av_log(matroska->ctx, AV_LOG_ERROR,
 530                    "Read error at pos. %"PRIu64" (0x%"PRIx64")\n",
 531                    pos, pos);
 532         }
 533         return AVERROR(EIO); /* EOS or actual I/O error */
 534     }
 535
 536     /* get the length of the EBML number */
 537     while (read <= max_size && !(total & len_mask)) {
 538         read++;
 539         len_mask >>= 1;
 540     }
 541     if (read > max_size) {
 542         int64_t pos = url_ftell(pb) - 1;
 543         av_log(matroska->ctx, AV_LOG_ERROR,
 544                "Invalid EBML number size tag 0x%02x at pos %"PRIu64" (0x%"PRIx64")\n",
 545                (uint8_t) total, pos, pos);
 546         return AVERROR_INVALIDDATA;
 547     }
 548
 549     /* read out length */
 550     total &= ~len_mask;
 551     while (n++ < read)
 552         total = (total << 8) | get_byte(pb);
 553
 554     *number = total;
 555
 556     return read;
 557 }
 558
 559 /*
 560  * Read the next element as an unsigned int.
 561  * 0 is success, < 0 is failure.
 562  */
 563 static int ebml_read_uint(ByteIOContext *pb, int size, uint64_t *num)
 564 {
 565     int n = 0;
 566
 567     if (size < 1 || size > 8)
 568         return AVERROR_INVALIDDATA;
 569
 570     /* big-endian ordering; build up number */
 571     *num = 0;
 572     while (n++ < size)
 573         *num = (*num << 8) | get_byte(pb);
 574
 575     return 0;
 576 }
 577
 578 /*
 579  * Read the next element as a float.
 580  * 0 is success, < 0 is failure.
 581  */
 582 static int ebml_read_float(ByteIOContext *pb, int size, double *num)
 583 {
 584     if (size == 4) {
 585         *num= av_int2flt(get_be32(pb));
 586     } else if(size==8){
 587         *num= av_int2dbl(get_be64(pb));
 588     } else
 589         return AVERROR_INVALIDDATA;
 590
 591     return 0;
 592 }
 593
 594 /*
 595  * Read the next element as an ASCII string.
 596  * 0 is success, < 0 is failure.
 597  */
 598 static int ebml_read_ascii(ByteIOContext *pb, int size, char **str)
 599 {
 600     av_free(*str);
 601     /* EBML strings are usually not 0-terminated, so we allocate one
 602      * byte more, read the string and NULL-terminate it ourselves. */
 603     if (!(*str = av_malloc(size + 1)))
 604         return AVERROR(ENOMEM);
 605     if (get_buffer(pb, (uint8_t *) *str, size) != size) {
 606         av_free(*str);
 607         return AVERROR(EIO);
 608     }
 609     (*str)[size] = '\0';
 610
 611     return 0;
 612 }
 613
 614 /*
 615  * Read the next element as binary data.
 616  * 0 is success, < 0 is failure.
 617  */
 618 static int ebml_read_binary(ByteIOContext *pb, int length, EbmlBin *bin)
 619 {
 620     av_free(bin->data);
 621     if (!(bin->data = av_malloc(length)))
 622         return AVERROR(ENOMEM);
 623
 624     bin->size = length;
 625     bin->pos  = url_ftell(pb);
 626     if (get_buffer(pb, bin->data, length) != length)
 627         return AVERROR(EIO);
 628
 629     return 0;
 630 }
 631
 632 /*
 633  * Read the next element, but only the header. The contents
 634  * are supposed to be sub-elements which can be read separately.
 635  * 0 is success, < 0 is failure.
 636  */
 637 static int ebml_read_master(MatroskaDemuxContext *matroska, int length)
 638 {
 639     ByteIOContext *pb = matroska->ctx->pb;
 640     MatroskaLevel *level;
 641
 642     if (matroska->num_levels >= EBML_MAX_DEPTH) {
 643         av_log(matroska->ctx, AV_LOG_ERROR,
 644                "File moves beyond max. allowed depth (%d)\n", EBML_MAX_DEPTH);
 645         return AVERROR(ENOSYS);
 646     }
 647
 648     level = &matroska->levels[matroska->num_levels++];
 649     level->start = url_ftell(pb);
 650     level->length = length;
 651
 652     return 0;
 653 }
 654
 655 /*
 656  * Read signed/unsigned "EBML" numbers.
 657  * Return: number of bytes processed, < 0 on error
 658  */
 659 static int matroska_ebmlnum_uint(MatroskaDemuxContext *matroska,
 660                                  uint8_t *data, uint32_t size, uint64_t *num)
 661 {
 662     ByteIOContext pb;
 663     init_put_byte(&pb, data, size, 0, NULL, NULL, NULL, NULL);
 664     return ebml_read_num(matroska, &pb, 8, num);
 665 }
 666
 667 /*
 668  * Same as above, but signed.
 669  */
 670 static int matroska_ebmlnum_sint(MatroskaDemuxContext *matroska,
 671                                  uint8_t *data, uint32_t size, int64_t *num)
 672 {
 673     uint64_t unum;
 674     int res;
 675
 676     /* read as unsigned number first */
 677     if ((res = matroska_ebmlnum_uint(matroska, data, size, &unum)) < 0)
 678         return res;
 679
 680     /* make signed (weird way) */
 681     *num = unum - ((1LL << (7*res - 1)) - 1);
 682
 683     return res;
 684 }
 685
 686 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
 687                            EbmlSyntax *syntax, void *data);
 688
 689 static int ebml_parse_id(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 690                          uint32_t id, void *data)
 691 {
 692     int i;
 693     for (i=0; syntax[i].id; i++)
 694         if (id == syntax[i].id)
 695             break;
 696     if (!syntax[i].id && id != EBML_ID_VOID && id != EBML_ID_CRC32)
 697         av_log(matroska->ctx, AV_LOG_INFO, "Unknown entry 0x%X\n", id);
 698     return ebml_parse_elem(matroska, &syntax[i], data);
 699 }
 700
 701 static int ebml_parse(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 702                       void *data)
 703 {
 704     uint64_t id;
 705     int res = ebml_read_num(matroska, matroska->ctx->pb, 4, &id);
 706     id |= 1 << 7*res;
 707     return res < 0 ? res : ebml_parse_id(matroska, syntax, id, data);
 708 }
 709
 710 static int ebml_parse_nest(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
 711                            void *data)
 712 {
 713     int i, res = 0;
 714
 715     for (i=0; syntax[i].id; i++)
 716         switch (syntax[i].type) {
 717         case EBML_UINT:
 718             *(uint64_t *)((char *)data+syntax[i].data_offset) = syntax[i].def.u;
 719             break;
 720         case EBML_FLOAT:
 721             *(double   *)((char *)data+syntax[i].data_offset) = syntax[i].def.f;
 722             break;
 723         case EBML_STR:
 724         case EBML_UTF8:
 725             *(char    **)((char *)data+syntax[i].data_offset) = av_strdup(syntax[i].def.s);
 726             break;
 727         }
 728
 729     while (!res && !ebml_level_end(matroska))
 730         res = ebml_parse(matroska, syntax, data);
 731
 732     return res;
 733 }
 734
 735 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
 736                            EbmlSyntax *syntax, void *data)
 737 {
 738     ByteIOContext *pb = matroska->ctx->pb;
 739     uint32_t id = syntax->id;
 740     uint64_t length;
 741     int res;
 742
 743     data = (char *)data + syntax->data_offset;
 744     if (syntax->list_elem_size) {
 745         EbmlList *list = data;
 746         list->elem = av_realloc(list->elem, (list->nb_elem+1)*syntax->list_elem_size);
 747         data = (char*)list->elem + list->nb_elem*syntax->list_elem_size;
 748         memset(data, 0, syntax->list_elem_size);
 749         list->nb_elem++;
 750     }
 751
 752     if (syntax->type != EBML_PASS && syntax->type != EBML_STOP)
 753         if ((res = ebml_read_num(matroska, pb, 8, &length)) < 0)
 754             return res;
 755
 756     switch (syntax->type) {
 757     case EBML_UINT:  res = ebml_read_uint  (pb, length, data);  break;
 758     case EBML_FLOAT: res = ebml_read_float (pb, length, data);  break;
 759     case EBML_STR:
 760     case EBML_UTF8:  res = ebml_read_ascii (pb, length, data);  break;
 761     case EBML_BIN:   res = ebml_read_binary(pb, length, data);  break;
 762     case EBML_NEST:  if ((res=ebml_read_master(matroska, length)) < 0)
 763                          return res;
 764                      if (id == MATROSKA_ID_SEGMENT)
 765                          matroska->segment_start = url_ftell(matroska->ctx->pb);
 766                      return ebml_parse_nest(matroska, syntax->def.n, data);
 767     case EBML_PASS:  return ebml_parse_id(matroska, syntax->def.n, id, data);
 768     case EBML_STOP:  *(int *)data = 1;      return 1;
 769     default:         return url_fseek(pb,length,SEEK_CUR)<0 ? AVERROR(EIO) : 0;
 770     }
 771     if (res == AVERROR_INVALIDDATA)
 772         av_log(matroska->ctx, AV_LOG_ERROR, "Invalid element\n");
 773     else if (res == AVERROR(EIO))
 774         av_log(matroska->ctx, AV_LOG_ERROR, "Read error\n");
 775     return res;
 776 }
 777
 778 static void ebml_free(EbmlSyntax *syntax, void *data)
 779 {
 780     int i, j;
 781     for (i=0; syntax[i].id; i++) {
 782         void *data_off = (char *)data + syntax[i].data_offset;
 783         switch (syntax[i].type) {
 784         case EBML_STR:
 785         case EBML_UTF8:  av_freep(data_off);                      break;
 786         case EBML_BIN:   av_freep(&((EbmlBin *)data_off)->data);  break;
 787         case EBML_NEST:
 788             if (syntax[i].list_elem_size) {
 789                 EbmlList *list = data_off;
 790                 char *ptr = list->elem;
 791                 for (j=0; j<list->nb_elem; j++, ptr+=syntax[i].list_elem_size)
 792                     ebml_free(syntax[i].def.n, ptr);
 793                 av_free(list->elem);
 794             } else
 795                 ebml_free(syntax[i].def.n, data_off);
 796         default:  break;
 797         }
 798     }
 799 }
 800
 801
 802 /*
 803  * Autodetecting...
 804  */
 805 static int matroska_probe(AVProbeData *p)
 806 {
 807     uint64_t total = 0;
 808     int len_mask = 0x80, size = 1, n = 1;
 809     static const char probe_data[] = "matroska";
 810
 811     /* EBML header? */
 812     if (AV_RB32(p->buf) != EBML_ID_HEADER)
 813         return 0;
 814
 815     /* length of header */
 816     total = p->buf[4];
 817     while (size <= 8 && !(total & len_mask)) {
 818         size++;
 819         len_mask >>= 1;
 820     }
 821     if (size > 8)
 822       return 0;
 823     total &= (len_mask - 1);
 824     while (n < size)
 825         total = (total << 8) | p->buf[4 + n++];
 826
 827     /* Does the probe data contain the whole header? */
 828     if (p->buf_size < 4 + size + total)
 829       return 0;
 830
 831     /* The header must contain the document type 'matroska'. For now,
 832      * we don't parse the whole header but simply check for the
 833      * availability of that array of characters inside the header.
 834      * Not fully fool-proof, but good enough. */
 835     for (n = 4+size; n <= 4+size+total-(sizeof(probe_data)-1); n++)
 836         if (!memcmp(p->buf+n, probe_data, sizeof(probe_data)-1))
 837             return AVPROBE_SCORE_MAX;
 838
 839     return 0;
 840 }
 841
 842 static MatroskaTrack *matroska_find_track_by_num(MatroskaDemuxContext *matroska,
 843                                                  int num)
 844 {
 845     MatroskaTrack *tracks = matroska->tracks.elem;
 846     int i;
 847
 848     for (i=0; i < matroska->tracks.nb_elem; i++)
 849         if (tracks[i].num == num)
 850             return &tracks[i];
 851
 852     av_log(matroska->ctx, AV_LOG_ERROR, "Invalid track number %d\n", num);
 853     return NULL;
 854 }
 855
 856 static int matroska_decode_buffer(uint8_t** buf, int* buf_size,
 857                                   MatroskaTrack *track)
 858 {
 859     MatroskaTrackEncoding *encodings = track->encodings.elem;
 860     uint8_t* data = *buf;
 861     int isize = *buf_size;
 862     uint8_t* pkt_data = NULL;
 863     int pkt_size = isize;
 864     int result = 0;
 865     int olen;
 866
 867     switch (encodings[0].compression.algo) {
 868     case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP:
 869         return encodings[0].compression.settings.size;
 870     case MATROSKA_TRACK_ENCODING_COMP_LZO:
 871         do {
 872             olen = pkt_size *= 3;
 873             pkt_data = av_realloc(pkt_data,
 874                                   pkt_size+LZO_OUTPUT_PADDING);
 875             result = lzo1x_decode(pkt_data, &olen, data, &isize);
 876         } while (result==LZO_OUTPUT_FULL && pkt_size<10000000);
 877         if (result)
 878             goto failed;
 879         pkt_size -= olen;
 880         break;
 881 #ifdef CONFIG_ZLIB
 882     case MATROSKA_TRACK_ENCODING_COMP_ZLIB: {
 883         z_stream zstream = {0};
 884         if (inflateInit(&zstream) != Z_OK)
 885             return -1;
 886         zstream.next_in = data;
 887         zstream.avail_in = isize;
 888         do {
 889             pkt_size *= 3;
 890             pkt_data = av_realloc(pkt_data, pkt_size);
 891             zstream.avail_out = pkt_size - zstream.total_out;
 892             zstream.next_out = pkt_data + zstream.total_out;
 893             result = inflate(&zstream, Z_NO_FLUSH);
 894         } while (result==Z_OK && pkt_size<10000000);
 895         pkt_size = zstream.total_out;
 896         inflateEnd(&zstream);
 897         if (result != Z_STREAM_END)
 898             goto failed;
 899         break;
 900     }
 901 #endif
 902 #ifdef CONFIG_BZLIB
 903     case MATROSKA_TRACK_ENCODING_COMP_BZLIB: {
 904         bz_stream bzstream = {0};
 905         if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
 906             return -1;
 907         bzstream.next_in = data;
 908         bzstream.avail_in = isize;
 909         do {
 910             pkt_size *= 3;
 911             pkt_data = av_realloc(pkt_data, pkt_size);
 912             bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
 913             bzstream.next_out = pkt_data + bzstream.total_out_lo32;
 914             result = BZ2_bzDecompress(&bzstream);
 915         } while (result==BZ_OK && pkt_size<10000000);
 916         pkt_size = bzstream.total_out_lo32;
 917         BZ2_bzDecompressEnd(&bzstream);
 918         if (result != BZ_STREAM_END)
 919             goto failed;
 920         break;
 921     }
 922 #endif
 923     default:
 924         return -1;
 925     }
 926
 927     *buf = pkt_data;
 928     *buf_size = pkt_size;
 929     return 0;
 930  failed:
 931     av_free(pkt_data);
 932     return -1;
 933 }
 934
 935 static void matroska_fix_ass_packet(MatroskaDemuxContext *matroska,
 936                                     AVPacket *pkt, uint64_t display_duration)
 937 {
 938     char *line, *layer, *ptr = pkt->data, *end = ptr+pkt->size;
 939     for (; *ptr!=',' && ptr<end-1; ptr++);
 940     if (*ptr == ',')
 941         layer = ++ptr;
 942     for (; *ptr!=',' && ptr<end-1; ptr++);
 943     if (*ptr == ',') {
 944         int64_t end_pts = pkt->pts + display_duration;
 945         int sc = matroska->time_scale * pkt->pts / 10000000;
 946         int ec = matroska->time_scale * end_pts  / 10000000;
 947         int sh, sm, ss, eh, em, es, len;
 948         sh = sc/360000;  sc -= 360000*sh;
 949         sm = sc/  6000;  sc -=   6000*sm;
 950         ss = sc/   100;  sc -=    100*ss;
 951         eh = ec/360000;  ec -= 360000*eh;
 952         em = ec/  6000;  ec -=   6000*em;
 953         es = ec/   100;  ec -=    100*es;
 954         *ptr++ = '\0';
 955         len = 50 + end-ptr + FF_INPUT_BUFFER_PADDING_SIZE;
 956         if (!(line = av_malloc(len)))
 957             return;
 958         snprintf(line,len,"Dialogue: %s,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s\r\n",
 959                  layer, sh, sm, ss, sc, eh, em, es, ec, ptr);
 960         av_free(pkt->data);
 961         pkt->data = line;
 962         pkt->size = strlen(line);
 963     }
 964 }
 965
 966 static void matroska_merge_packets(AVPacket *out, AVPacket *in)
 967 {
 968     out->data = av_realloc(out->data, out->size+in->size);
 969     memcpy(out->data+out->size, in->data, in->size);
 970     out->size += in->size;
 971     av_destruct_packet(in);
 972     av_free(in);
 973 }
 974
 975 static void matroska_convert_tags(AVFormatContext *s, EbmlList *list)
 976 {
 977     MatroskaTag *tags = list->elem;
 978     int i, j;
 979
 980     for (i=0; i < list->nb_elem; i++) {
 981         for (j=0; j < FF_ARRAY_ELEMS(metadata); j++){
 982             if (!strcmp(tags[i].name, metadata[j].name)) {
 983                 int *ptr = (int *)((char *)s + metadata[j].offset);
 984                 if (*ptr)  continue;
 985                 if (metadata[j].size > sizeof(int))
 986                     av_strlcpy((char *)ptr, tags[i].string, metadata[j].size);
 987                 else
 988                     *ptr = atoi(tags[i].string);
 989             }
 990         }
 991         if (tags[i].sub.nb_elem)
 992             matroska_convert_tags(s, &tags[i].sub);
 993     }
 994 }
 995
 996 static void matroska_execute_seekhead(MatroskaDemuxContext *matroska)
 997 {
 998     EbmlList *seekhead_list = &matroska->seekhead;
 999     MatroskaSeekhead *seekhead = seekhead_list->elem;
1000     uint32_t level_up = matroska->level_up;
1001     int64_t before_pos = url_ftell(matroska->ctx->pb);
1002     MatroskaLevel level;
1003     int i;
1004
1005     for (i=0; i<seekhead_list->nb_elem; i++) {
1006         int64_t offset = seekhead[i].pos + matroska->segment_start;
1007
1008         if (seekhead[i].pos <= before_pos
1009             || seekhead[i].id == MATROSKA_ID_SEEKHEAD
1010             || seekhead[i].id == MATROSKA_ID_CLUSTER)
1011             continue;
1012
1013         /* seek */
1014         if (url_fseek(matroska->ctx->pb, offset, SEEK_SET) != offset)
1015             continue;
1016
1017         /* We don't want to lose our seekhead level, so we add
1018          * a dummy. This is a crude hack. */
1019         if (matroska->num_levels == EBML_MAX_DEPTH) {
1020             av_log(matroska->ctx, AV_LOG_INFO,
1021                    "Max EBML element depth (%d) reached, "
1022                    "cannot parse further.\n", EBML_MAX_DEPTH);
1023             break;
1024         }
1025
1026         level.start = 0;
1027         level.length = (uint64_t)-1;
1028         matroska->levels[matroska->num_levels] = level;
1029         matroska->num_levels++;
1030
1031         ebml_parse(matroska, matroska_segment, matroska);
1032
1033         /* remove dummy level */
1034         while (matroska->num_levels) {
1035             uint64_t length = matroska->levels[--matroska->num_levels].length;
1036             if (length == (uint64_t)-1)
1037                 break;
1038         }
1039     }
1040
1041     /* seek back */
1042     url_fseek(matroska->ctx->pb, before_pos, SEEK_SET);
1043     matroska->level_up = level_up;
1044 }
1045
1046 static int matroska_aac_profile(char *codec_id)
1047 {
1048     static const char * const aac_profiles[] = { "MAIN", "LC", "SSR" };
1049     int profile;
1050
1051     for (profile=0; profile<FF_ARRAY_ELEMS(aac_profiles); profile++)
1052         if (strstr(codec_id, aac_profiles[profile]))
1053             break;
1054     return profile + 1;
1055 }
1056
1057 static int matroska_aac_sri(int samplerate)
1058 {
1059     int sri;
1060
1061     for (sri=0; sri<FF_ARRAY_ELEMS(ff_mpeg4audio_sample_rates); sri++)
1062         if (ff_mpeg4audio_sample_rates[sri] == samplerate)
1063             break;
1064     return sri;
1065 }
1066
1067 static int matroska_read_header(AVFormatContext *s, AVFormatParameters *ap)
1068 {
1069     MatroskaDemuxContext *matroska = s->priv_data;
1070     EbmlList *attachements_list = &matroska->attachments;
1071     MatroskaAttachement *attachements;
1072     EbmlList *chapters_list = &matroska->chapters;
1073     MatroskaChapter *chapters;
1074     MatroskaTrack *tracks;
1075     EbmlList *index_list;
1076     MatroskaIndex *index;
1077     Ebml ebml = { 0 };
1078     AVStream *st;
1079     int i, j;
1080
1081     matroska->ctx = s;
1082
1083     /* First read the EBML header. */
1084     if (ebml_parse(matroska, ebml_syntax, &ebml)
1085         || ebml.version > EBML_VERSION       || ebml.max_size > sizeof(uint64_t)
1086         || ebml.id_length > sizeof(uint32_t) || strcmp(ebml.doctype, "matroska")
1087         || ebml.doctype_version > 2) {
1088         av_log(matroska->ctx, AV_LOG_ERROR,
1089                "EBML header using unsupported features\n"
1090                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
1091                ebml.version, ebml.doctype, ebml.doctype_version);
1092         return AVERROR_NOFMT;
1093     }
1094     ebml_free(ebml_syntax, &ebml);
1095
1096     /* The next thing is a segment. */
1097     if (ebml_parse(matroska, matroska_segments, matroska) < 0)
1098         return -1;
1099     matroska_execute_seekhead(matroska);
1100
1101     if (matroska->duration)
1102         matroska->ctx->duration = matroska->duration * matroska->time_scale
1103                                   * 1000 / AV_TIME_BASE;
1104     if (matroska->title)
1105         strncpy(matroska->ctx->title, matroska->title,
1106                 sizeof(matroska->ctx->title)-1);
1107     matroska_convert_tags(s, &matroska->tags);
1108
1109     tracks = matroska->tracks.elem;
1110     for (i=0; i < matroska->tracks.nb_elem; i++) {
1111         MatroskaTrack *track = &tracks[i];
1112         enum CodecID codec_id = CODEC_ID_NONE;
1113         EbmlList *encodings_list = &tracks->encodings;
1114         MatroskaTrackEncoding *encodings = encodings_list->elem;
1115         uint8_t *extradata = NULL;
1116         int extradata_size = 0;
1117         int extradata_offset = 0;
1118
1119         /* Apply some sanity checks. */
1120         if (track->type != MATROSKA_TRACK_TYPE_VIDEO &&
1121             track->type != MATROSKA_TRACK_TYPE_AUDIO &&
1122             track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
1123             av_log(matroska->ctx, AV_LOG_INFO,
1124                    "Unknown or unsupported track type %"PRIu64"\n",
1125                    track->type);
1126             continue;
1127         }
1128         if (track->codec_id == NULL)
1129             continue;
1130
1131         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1132             if (!track->default_duration)
1133                 track->default_duration = 1000000000/track->video.frame_rate;
1134             if (!track->video.display_width)
1135                 track->video.display_width = track->video.pixel_width;
1136             if (!track->video.display_height)
1137                 track->video.display_height = track->video.pixel_height;
1138         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1139             if (!track->audio.out_samplerate)
1140                 track->audio.out_samplerate = track->audio.samplerate;
1141         }
1142         if (encodings_list->nb_elem > 1) {
1143             av_log(matroska->ctx, AV_LOG_ERROR,
1144                    "Multiple combined encodings no supported");
1145         } else if (encodings_list->nb_elem == 1) {
1146             if (encodings[0].type ||
1147                 (encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP &&
1148 #ifdef CONFIG_ZLIB
1149                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_ZLIB &&
1150 #endif
1151 #ifdef CONFIG_BZLIB
1152                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_BZLIB &&
1153 #endif
1154                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_LZO)) {
1155                 encodings[0].scope = 0;
1156                 av_log(matroska->ctx, AV_LOG_ERROR,
1157                        "Unsupported encoding type");
1158             } else if (track->codec_priv.size && encodings[0].scope&2) {
1159                 uint8_t *codec_priv = track->codec_priv.data;
1160                 int offset = matroska_decode_buffer(&track->codec_priv.data,
1161                                                     &track->codec_priv.size,
1162                                                     track);
1163                 if (offset < 0) {
1164                     track->codec_priv.data = NULL;
1165                     track->codec_priv.size = 0;
1166                     av_log(matroska->ctx, AV_LOG_ERROR,
1167                            "Failed to decode codec private data\n");
1168                 } else if (offset > 0) {
1169                     track->codec_priv.data = av_malloc(track->codec_priv.size + offset);
1170                     memcpy(track->codec_priv.data,
1171                            encodings[0].compression.settings.data, offset);
1172                     memcpy(track->codec_priv.data+offset, codec_priv,
1173                            track->codec_priv.size);
1174                     track->codec_priv.size += offset;
1175                 }
1176                 if (codec_priv != track->codec_priv.data)
1177                     av_free(codec_priv);
1178             }
1179         }
1180
1181         for(j=0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++){
1182             if(!strncmp(ff_mkv_codec_tags[j].str, track->codec_id,
1183                         strlen(ff_mkv_codec_tags[j].str))){
1184                 codec_id= ff_mkv_codec_tags[j].id;
1185                 break;
1186             }
1187         }
1188
1189         st = track->stream = av_new_stream(s, 0);
1190         if (st == NULL)
1191             return AVERROR(ENOMEM);
1192
1193         if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC")
1194             && track->codec_priv.size >= 40
1195             && track->codec_priv.data != NULL) {
1196             track->video.fourcc = AV_RL32(track->codec_priv.data + 16);
1197             codec_id = codec_get_id(codec_bmp_tags, track->video.fourcc);
1198         } else if (!strcmp(track->codec_id, "A_MS/ACM")
1199                    && track->codec_priv.size >= 18
1200                    && track->codec_priv.data != NULL) {
1201             uint16_t tag = AV_RL16(track->codec_priv.data);
1202             codec_id = codec_get_id(codec_wav_tags, tag);
1203         } else if (!strcmp(track->codec_id, "V_QUICKTIME")
1204                    && (track->codec_priv.size >= 86)
1205                    && (track->codec_priv.data != NULL)) {
1206             track->video.fourcc = AV_RL32(track->codec_priv.data);
1207             codec_id=codec_get_id(codec_movvideo_tags, track->video.fourcc);
1208         } else if (codec_id == CODEC_ID_PCM_S16BE) {
1209             switch (track->audio.bitdepth) {
1210             case  8:  codec_id = CODEC_ID_PCM_U8;     break;
1211             case 24:  codec_id = CODEC_ID_PCM_S24BE;  break;
1212             case 32:  codec_id = CODEC_ID_PCM_S32BE;  break;
1213             }
1214         } else if (codec_id == CODEC_ID_PCM_S16LE) {
1215             switch (track->audio.bitdepth) {
1216             case  8:  codec_id = CODEC_ID_PCM_U8;     break;
1217             case 24:  codec_id = CODEC_ID_PCM_S24LE;  break;
1218             case 32:  codec_id = CODEC_ID_PCM_S32LE;  break;
1219             }
1220         } else if (codec_id==CODEC_ID_PCM_F32LE && track->audio.bitdepth==64) {
1221             codec_id = CODEC_ID_PCM_F64LE;
1222         } else if (codec_id == CODEC_ID_AAC && !track->codec_priv.size) {
1223             int profile = matroska_aac_profile(track->codec_id);
1224             int sri = matroska_aac_sri(track->audio.samplerate);
1225             extradata = av_malloc(5);
1226             if (extradata == NULL)
1227                 return AVERROR(ENOMEM);
1228             extradata[0] = (profile << 3) | ((sri&0x0E) >> 1);
1229             extradata[1] = ((sri&0x01) << 7) | (track->audio.channels<<3);
1230             if (strstr(track->codec_id, "SBR")) {
1231                 sri = matroska_aac_sri(track->audio.out_samplerate);
1232                 extradata[2] = 0x56;
1233                 extradata[3] = 0xE5;
1234                 extradata[4] = 0x80 | (sri<<3);
1235                 extradata_size = 5;
1236             } else
1237                 extradata_size = 2;
1238         } else if (codec_id == CODEC_ID_TTA) {
1239             ByteIOContext b;
1240             extradata_size = 30;
1241             extradata = av_mallocz(extradata_size);
1242             if (extradata == NULL)
1243                 return AVERROR(ENOMEM);
1244             init_put_byte(&b, extradata, extradata_size, 1,
1245                           NULL, NULL, NULL, NULL);
1246             put_buffer(&b, "TTA1", 4);
1247             put_le16(&b, 1);
1248             put_le16(&b, track->audio.channels);
1249             put_le16(&b, track->audio.bitdepth);
1250             put_le32(&b, track->audio.out_samplerate);
1251             put_le32(&b, matroska->ctx->duration * track->audio.out_samplerate);
1252         } else if (codec_id == CODEC_ID_RV10 || codec_id == CODEC_ID_RV20 ||
1253                    codec_id == CODEC_ID_RV30 || codec_id == CODEC_ID_RV40) {
1254             extradata_offset = 26;
1255             track->codec_priv.size -= extradata_offset;
1256         } else if (codec_id == CODEC_ID_RA_144) {
1257             track->audio.out_samplerate = 8000;
1258             track->audio.channels = 1;
1259         } else if (codec_id == CODEC_ID_RA_288 || codec_id == CODEC_ID_COOK ||
1260                    codec_id == CODEC_ID_ATRAC3) {
1261             ByteIOContext b;
1262
1263             init_put_byte(&b, track->codec_priv.data,track->codec_priv.size,
1264                           0, NULL, NULL, NULL, NULL);
1265             url_fskip(&b, 24);
1266             track->audio.coded_framesize = get_be32(&b);
1267             url_fskip(&b, 12);
1268             track->audio.sub_packet_h    = get_be16(&b);
1269             track->audio.frame_size      = get_be16(&b);
1270             track->audio.sub_packet_size = get_be16(&b);
1271             track->audio.buf = av_malloc(track->audio.frame_size * track->audio.sub_packet_h);
1272             if (codec_id == CODEC_ID_RA_288) {
1273                 st->codec->block_align = track->audio.coded_framesize;
1274                 track->codec_priv.size = 0;
1275             } else {
1276                 st->codec->block_align = track->audio.sub_packet_size;
1277                 extradata_offset = 78;
1278                 track->codec_priv.size -= extradata_offset;
1279             }
1280         }
1281
1282         if (codec_id == CODEC_ID_NONE)
1283             av_log(matroska->ctx, AV_LOG_INFO,
1284                    "Unknown/unsupported CodecID %s.\n", track->codec_id);
1285
1286         if (track->time_scale < 0.01)
1287             track->time_scale = 1.0;
1288         av_set_pts_info(st, 64, matroska->time_scale*track->time_scale, 1000*1000*1000); /* 64 bit pts in ns */
1289
1290         st->codec->codec_id = codec_id;
1291         st->start_time = 0;
1292         if (strcmp(track->language, "und"))
1293             av_strlcpy(st->language, track->language, 4);
1294
1295         if (track->flag_default)
1296             st->disposition |= AV_DISPOSITION_DEFAULT;
1297
1298         if (track->default_duration)
1299             av_reduce(&st->codec->time_base.num, &st->codec->time_base.den,
1300                       track->default_duration, 1000000000, 30000);
1301
1302         if(extradata){
1303             st->codec->extradata = extradata;
1304             st->codec->extradata_size = extradata_size;
1305         } else if(track->codec_priv.data && track->codec_priv.size > 0){
1306             st->codec->extradata = av_malloc(track->codec_priv.size);
1307             if(st->codec->extradata == NULL)
1308                 return AVERROR(ENOMEM);
1309             st->codec->extradata_size = track->codec_priv.size;
1310             memcpy(st->codec->extradata,
1311                    track->codec_priv.data + extradata_offset,
1312                    track->codec_priv.size);
1313         }
1314
1315         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1316             st->codec->codec_type = CODEC_TYPE_VIDEO;
1317             st->codec->codec_tag  = track->video.fourcc;
1318             st->codec->width  = track->video.pixel_width;
1319             st->codec->height = track->video.pixel_height;
1320             av_reduce(&st->sample_aspect_ratio.num,
1321                       &st->sample_aspect_ratio.den,
1322                       st->codec->height * track->video.display_width,
1323                       st->codec-> width * track->video.display_height,
1324                       255);
1325             st->need_parsing = AVSTREAM_PARSE_HEADERS;
1326         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1327             st->codec->codec_type = CODEC_TYPE_AUDIO;
1328             st->codec->sample_rate = track->audio.out_samplerate;
1329             st->codec->channels = track->audio.channels;
1330         } else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
1331             st->codec->codec_type = CODEC_TYPE_SUBTITLE;
1332         }
1333     }
1334
1335     attachements = attachements_list->elem;
1336     for (j=0; j<attachements_list->nb_elem; j++) {
1337         if (!(attachements[j].filename && attachements[j].mime &&
1338               attachements[j].bin.data && attachements[j].bin.size > 0)) {
1339             av_log(matroska->ctx, AV_LOG_ERROR, "incomplete attachment\n");
1340         } else {
1341             AVStream *st = av_new_stream(s, 0);
1342             if (st == NULL)
1343                 break;
1344             st->filename          = av_strdup(attachements[j].filename);
1345             st->codec->codec_id = CODEC_ID_NONE;
1346             st->codec->codec_type = CODEC_TYPE_ATTACHMENT;
1347             st->codec->extradata  = av_malloc(attachements[j].bin.size);
1348             if(st->codec->extradata == NULL)
1349                 break;
1350             st->codec->extradata_size = attachements[j].bin.size;
1351             memcpy(st->codec->extradata, attachements[j].bin.data, attachements[j].bin.size);
1352
1353             for (i=0; ff_mkv_mime_tags[i].id != CODEC_ID_NONE; i++) {
1354                 if (!strncmp(ff_mkv_mime_tags[i].str, attachements[j].mime,
1355                              strlen(ff_mkv_mime_tags[i].str))) {
1356                     st->codec->codec_id = ff_mkv_mime_tags[i].id;
1357                     break;
1358                 }
1359             }
1360         }
1361     }
1362
1363     chapters = chapters_list->elem;
1364     for (i=0; i<chapters_list->nb_elem; i++)
1365         if (chapters[i].start != AV_NOPTS_VALUE && chapters[i].uid)
1366             ff_new_chapter(s, chapters[i].uid, (AVRational){1, 1000000000},
1367                            chapters[i].start, chapters[i].end,
1368                            chapters[i].title);
1369
1370     index_list = &matroska->index;
1371     index = index_list->elem;
1372     for (i=0; i<index_list->nb_elem; i++) {
1373         EbmlList *pos_list = &index[i].pos;
1374         MatroskaIndexPos *pos = pos_list->elem;
1375         for (j=0; j<pos_list->nb_elem; j++) {
1376             MatroskaTrack *track = matroska_find_track_by_num(matroska,
1377                                                               pos[j].track);
1378             if (track && track->stream)
1379                 av_add_index_entry(track->stream,
1380                                    pos[j].pos + matroska->segment_start,
1381                                    index[i].time, 0, 0, AVINDEX_KEYFRAME);
1382         }
1383     }
1384
1385     return 0;
1386 }
1387
1388 /*
1389  * Put one packet in an application-supplied AVPacket struct.
1390  * Returns 0 on success or -1 on failure.
1391  */
1392 static int matroska_deliver_packet(MatroskaDemuxContext *matroska,
1393                                    AVPacket *pkt)
1394 {
1395     if (matroska->num_packets > 0) {
1396         memcpy(pkt, matroska->packets[0], sizeof(AVPacket));
1397         av_free(matroska->packets[0]);
1398         if (matroska->num_packets > 1) {
1399             memmove(&matroska->packets[0], &matroska->packets[1],
1400                     (matroska->num_packets - 1) * sizeof(AVPacket *));
1401             matroska->packets =
1402                 av_realloc(matroska->packets, (matroska->num_packets - 1) *
1403                            sizeof(AVPacket *));
1404         } else {
1405             av_freep(&matroska->packets);
1406         }
1407         matroska->num_packets--;
1408         return 0;
1409     }
1410
1411     return -1;
1412 }
1413
1414 /*
1415  * Free all packets in our internal queue.
1416  */
1417 static void matroska_clear_queue(MatroskaDemuxContext *matroska)
1418 {
1419     if (matroska->packets) {
1420         int n;
1421         for (n = 0; n < matroska->num_packets; n++) {
1422             av_free_packet(matroska->packets[n]);
1423             av_free(matroska->packets[n]);
1424         }
1425         av_freep(&matroska->packets);
1426         matroska->num_packets = 0;
1427     }
1428 }
1429
1430 static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
1431                                 int size, int64_t pos, uint64_t cluster_time,
1432                                 uint64_t duration, int is_keyframe,
1433                                 int64_t cluster_pos)
1434 {
1435     uint64_t timecode = AV_NOPTS_VALUE;
1436     MatroskaTrack *track;
1437     int res = 0;
1438     AVStream *st;
1439     AVPacket *pkt;
1440     int16_t block_time;
1441     uint32_t *lace_size = NULL;
1442     int n, flags, laces = 0;
1443     uint64_t num;
1444
1445     if ((n = matroska_ebmlnum_uint(matroska, data, size, &num)) < 0) {
1446         av_log(matroska->ctx, AV_LOG_ERROR, "EBML block data error\n");
1447         return res;
1448     }
1449     data += n;
1450     size -= n;
1451
1452     track = matroska_find_track_by_num(matroska, num);
1453     if (size <= 3 || !track || !track->stream) {
1454         av_log(matroska->ctx, AV_LOG_INFO,
1455                "Invalid stream %"PRIu64" or size %u\n", num, size);
1456         return res;
1457     }
1458     st = track->stream;
1459     if (st->discard >= AVDISCARD_ALL)
1460         return res;
1461     if (duration == AV_NOPTS_VALUE)
1462         duration = track->default_duration / matroska->time_scale;
1463
1464     block_time = AV_RB16(data);
1465     data += 2;
1466     flags = *data++;
1467     size -= 3;
1468     if (is_keyframe == -1)
1469         is_keyframe = flags & 0x80 ? PKT_FLAG_KEY : 0;
1470
1471     if (cluster_time != (uint64_t)-1
1472         && (block_time >= 0 || cluster_time >= -block_time)) {
1473         timecode = cluster_time + block_time;
1474         if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE
1475             && timecode < track->end_timecode)
1476             is_keyframe = 0;  /* overlapping subtitles are not key frame */
1477         if (is_keyframe)
1478             av_add_index_entry(st, cluster_pos, timecode, 0,0,AVINDEX_KEYFRAME);
1479         track->end_timecode = FFMAX(track->end_timecode, timecode+duration);
1480     }
1481
1482     if (matroska->skip_to_keyframe && track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
1483         if (!is_keyframe || timecode < matroska->skip_to_timecode)
1484             return res;
1485         matroska->skip_to_keyframe = 0;
1486     }
1487
1488     switch ((flags & 0x06) >> 1) {
1489         case 0x0: /* no lacing */
1490             laces = 1;
1491             lace_size = av_mallocz(sizeof(int));
1492             lace_size[0] = size;
1493             break;
1494
1495         case 0x1: /* Xiph lacing */
1496         case 0x2: /* fixed-size lacing */
1497         case 0x3: /* EBML lacing */
1498             assert(size>0); // size <=3 is checked before size-=3 above
1499             laces = (*data) + 1;
1500             data += 1;
1501             size -= 1;
1502             lace_size = av_mallocz(laces * sizeof(int));
1503
1504             switch ((flags & 0x06) >> 1) {
1505                 case 0x1: /* Xiph lacing */ {
1506                     uint8_t temp;
1507                     uint32_t total = 0;
1508                     for (n = 0; res == 0 && n < laces - 1; n++) {
1509                         while (1) {
1510                             if (size == 0) {
1511                                 res = -1;
1512                                 break;
1513                             }
1514                             temp = *data;
1515                             lace_size[n] += temp;
1516                             data += 1;
1517                             size -= 1;
1518                             if (temp != 0xff)
1519                                 break;
1520                         }
1521                         total += lace_size[n];
1522                     }
1523                     lace_size[n] = size - total;
1524                     break;
1525                 }
1526
1527                 case 0x2: /* fixed-size lacing */
1528                     for (n = 0; n < laces; n++)
1529                         lace_size[n] = size / laces;
1530                     break;
1531
1532                 case 0x3: /* EBML lacing */ {
1533                     uint32_t total;
1534                     n = matroska_ebmlnum_uint(matroska, data, size, &num);
1535                     if (n < 0) {
1536                         av_log(matroska->ctx, AV_LOG_INFO,
1537                                "EBML block data error\n");
1538                         break;
1539                     }
1540                     data += n;
1541                     size -= n;
1542                     total = lace_size[0] = num;
1543                     for (n = 1; res == 0 && n < laces - 1; n++) {
1544                         int64_t snum;
1545                         int r;
1546                         r = matroska_ebmlnum_sint(matroska, data, size, &snum);
1547                         if (r < 0) {
1548                             av_log(matroska->ctx, AV_LOG_INFO,
1549                                    "EBML block data error\n");
1550                             break;
1551                         }
1552                         data += r;
1553                         size -= r;
1554                         lace_size[n] = lace_size[n - 1] + snum;
1555                         total += lace_size[n];
1556                     }
1557                     lace_size[n] = size - total;
1558                     break;
1559                 }
1560             }
1561             break;
1562     }
1563
1564     if (res == 0) {
1565         for (n = 0; n < laces; n++) {
1566             if (st->codec->codec_id == CODEC_ID_RA_288 ||
1567                 st->codec->codec_id == CODEC_ID_COOK ||
1568                 st->codec->codec_id == CODEC_ID_ATRAC3) {
1569                 int a = st->codec->block_align;
1570                 int sps = track->audio.sub_packet_size;
1571                 int cfs = track->audio.coded_framesize;
1572                 int h = track->audio.sub_packet_h;
1573                 int y = track->audio.sub_packet_cnt;
1574                 int w = track->audio.frame_size;
1575                 int x;
1576
1577                 if (!track->audio.pkt_cnt) {
1578                     if (st->codec->codec_id == CODEC_ID_RA_288)
1579                         for (x=0; x<h/2; x++)
1580                             memcpy(track->audio.buf+x*2*w+y*cfs,
1581                                    data+x*cfs, cfs);
1582                     else
1583                         for (x=0; x<w/sps; x++)
1584                             memcpy(track->audio.buf+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), data+x*sps, sps);
1585
1586                     if (++track->audio.sub_packet_cnt >= h) {
1587                         track->audio.sub_packet_cnt = 0;
1588                         track->audio.pkt_cnt = h*w / a;
1589                     }
1590                 }
1591                 while (track->audio.pkt_cnt) {
1592                     pkt = av_mallocz(sizeof(AVPacket));
1593                     av_new_packet(pkt, a);
1594                     memcpy(pkt->data, track->audio.buf
1595                            + a * (h*w / a - track->audio.pkt_cnt--), a);
1596                     pkt->pos = pos;
1597                     pkt->stream_index = st->index;
1598                     dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
1599                 }
1600             } else {
1601                 MatroskaTrackEncoding *encodings = track->encodings.elem;
1602                 int offset = 0, pkt_size = lace_size[n];
1603                 uint8_t *pkt_data = data;
1604
1605                 if (encodings && encodings->scope & 1) {
1606                     offset = matroska_decode_buffer(&pkt_data,&pkt_size, track);
1607                     if (offset < 0)
1608                         continue;
1609                 }
1610
1611                 pkt = av_mallocz(sizeof(AVPacket));
1612                 /* XXX: prevent data copy... */
1613                 if (av_new_packet(pkt, pkt_size+offset) < 0) {
1614                     av_free(pkt);
1615                     res = AVERROR(ENOMEM);
1616                     n = laces-1;
1617                     break;
1618                 }
1619                 if (offset)
1620                     memcpy (pkt->data, encodings->compression.settings.data, offset);
1621                 memcpy (pkt->data+offset, pkt_data, pkt_size);
1622
1623                 if (pkt_data != data)
1624                     av_free(pkt_data);
1625
1626                 if (n == 0)
1627                     pkt->flags = is_keyframe;
1628                 pkt->stream_index = st->index;
1629
1630                 pkt->pts = timecode;
1631                 pkt->pos = pos;
1632                 if (st->codec->codec_id == CODEC_ID_TEXT)
1633                     pkt->convergence_duration = duration;
1634                 else if (track->type != MATROSKA_TRACK_TYPE_SUBTITLE)
1635                     pkt->duration = duration;
1636
1637                 if (st->codec->codec_id == CODEC_ID_SSA)
1638                     matroska_fix_ass_packet(matroska, pkt, duration);
1639
1640                 if (matroska->prev_pkt &&
1641                     timecode != AV_NOPTS_VALUE &&
1642                     matroska->prev_pkt->pts == timecode &&
1643                     matroska->prev_pkt->stream_index == st->index)
1644                     matroska_merge_packets(matroska->prev_pkt, pkt);
1645                 else {
1646                     dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
1647                     matroska->prev_pkt = pkt;
1648                 }
1649             }
1650
1651             if (timecode != AV_NOPTS_VALUE)
1652                 timecode = duration ? timecode + duration : AV_NOPTS_VALUE;
1653             data += lace_size[n];
1654         }
1655     }
1656
1657     av_free(lace_size);
1658     return res;
1659 }
1660
1661 static int matroska_parse_cluster(MatroskaDemuxContext *matroska)
1662 {
1663     MatroskaCluster cluster = { 0 };
1664     EbmlList *blocks_list;
1665     MatroskaBlock *blocks;
1666     int i, res;
1667     int64_t pos = url_ftell(matroska->ctx->pb);
1668     matroska->prev_pkt = NULL;
1669     if (matroska->has_cluster_id){
1670         /* For the first cluster we parse, its ID was already read as
1671            part of matroska_read_header(), so don't read it again */
1672         res = ebml_parse_id(matroska, matroska_clusters,
1673                             MATROSKA_ID_CLUSTER, &cluster);
1674         pos -= 4;  /* sizeof the ID which was already read */
1675         matroska->has_cluster_id = 0;
1676     } else
1677         res = ebml_parse(matroska, matroska_clusters, &cluster);
1678     blocks_list = &cluster.blocks;
1679     blocks = blocks_list->elem;
1680     for (i=0; i<blocks_list->nb_elem; i++)
1681         if (blocks[i].bin.size > 0)
1682             res=matroska_parse_block(matroska,
1683                                      blocks[i].bin.data, blocks[i].bin.size,
1684                                      blocks[i].bin.pos,  cluster.timecode,
1685                                      blocks[i].duration, !blocks[i].reference,
1686                                      pos);
1687     ebml_free(matroska_cluster, &cluster);
1688     if (res < 0)  matroska->done = 1;
1689     return res;
1690 }
1691
1692 static int matroska_read_packet(AVFormatContext *s, AVPacket *pkt)
1693 {
1694     MatroskaDemuxContext *matroska = s->priv_data;
1695
1696     while (matroska_deliver_packet(matroska, pkt)) {
1697         if (matroska->done)
1698             return AVERROR(EIO);
1699         matroska_parse_cluster(matroska);
1700     }
1701
1702     return 0;
1703 }
1704
1705 static int matroska_read_seek(AVFormatContext *s, int stream_index,
1706                               int64_t timestamp, int flags)
1707 {
1708     MatroskaDemuxContext *matroska = s->priv_data;
1709     MatroskaTrack *tracks = matroska->tracks.elem;
1710     AVStream *st = s->streams[stream_index];
1711     int i, index, index_sub, index_min;
1712
1713     if (!st->nb_index_entries)
1714         return 0;
1715     timestamp = FFMAX(timestamp, st->index_entries[0].timestamp);
1716
1717     if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
1718         url_fseek(s->pb, st->index_entries[st->nb_index_entries-1].pos, SEEK_SET);
1719         while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
1720             matroska_clear_queue(matroska);
1721             if (matroska_parse_cluster(matroska) < 0)
1722                 break;
1723         }
1724     }
1725
1726     matroska_clear_queue(matroska);
1727     if (index < 0)
1728         return 0;
1729
1730     index_min = index;
1731     for (i=0; i < matroska->tracks.nb_elem; i++) {
1732         tracks[i].end_timecode = 0;
1733         if (tracks[i].type == MATROSKA_TRACK_TYPE_SUBTITLE
1734             && !tracks[i].stream->discard != AVDISCARD_ALL) {
1735             index_sub = av_index_search_timestamp(tracks[i].stream, st->index_entries[index].timestamp, AVSEEK_FLAG_BACKWARD);
1736             if (index_sub >= 0
1737                 && st->index_entries[index_sub].pos < st->index_entries[index_min].pos
1738                 && st->index_entries[index].timestamp - st->index_entries[index_sub].timestamp < 30000000000/matroska->time_scale)
1739                 index_min = index_sub;
1740         }
1741     }
1742
1743     url_fseek(s->pb, st->index_entries[index_min].pos, SEEK_SET);
1744     matroska->skip_to_keyframe = !(flags & AVSEEK_FLAG_ANY);
1745     matroska->skip_to_timecode = st->index_entries[index].timestamp;
1746     matroska->done = 0;
1747     av_update_cur_dts(s, st, st->index_entries[index].timestamp);
1748     return 0;
1749 }
1750
1751 static int matroska_read_close(AVFormatContext *s)
1752 {
1753     MatroskaDemuxContext *matroska = s->priv_data;
1754     MatroskaTrack *tracks = matroska->tracks.elem;
1755     int n;
1756
1757     matroska_clear_queue(matroska);
1758
1759     for (n=0; n < matroska->tracks.nb_elem; n++)
1760         if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)
1761             av_free(tracks[n].audio.buf);
1762     ebml_free(matroska_segment, matroska);
1763
1764     return 0;
1765 }
1766
1767 AVInputFormat matroska_demuxer = {
1768     "matroska",
1769     NULL_IF_CONFIG_SMALL("Matroska file format"),
1770     sizeof(MatroskaDemuxContext),
1771     matroska_probe,
1772     matroska_read_header,
1773     matroska_read_packet,
1774     matroska_read_close,
1775     matroska_read_seek,
1776 };