FFmpeg: libavformat/matroskadec.c Source File

00001 /*
00002  * Matroska file demuxer
00003  * Copyright (c) 2003-2008 The FFmpeg Project
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00031 #include <stdio.h>
00032 #include "avformat.h"
00033 #include "internal.h"
00034 #include "avio_internal.h"
00035 /* For ff_codec_get_id(). */
00036 #include "riff.h"
00037 #include "isom.h"
00038 #include "rm.h"
00039 #include "matroska.h"
00040 #include "libavcodec/mpeg4audio.h"
00041 #include "libavutil/intfloat.h"
00042 #include "libavutil/intreadwrite.h"
00043 #include "libavutil/avstring.h"
00044 #include "libavutil/lzo.h"
00045 #include "libavutil/dict.h"
00046 #if CONFIG_ZLIB
00047 #include <zlib.h>
00048 #endif
00049 #if CONFIG_BZLIB
00050 #include <bzlib.h>
00051 #endif
00052 
00053 typedef enum {
00054     EBML_NONE,
00055     EBML_UINT,
00056     EBML_FLOAT,
00057     EBML_STR,
00058     EBML_UTF8,
00059     EBML_BIN,
00060     EBML_NEST,
00061     EBML_PASS,
00062     EBML_STOP,
00063     EBML_TYPE_COUNT
00064 } EbmlType;
00065 
00066 typedef const struct EbmlSyntax {
00067     uint32_t id;
00068     EbmlType type;
00069     int list_elem_size;
00070     int data_offset;
00071     union {
00072         uint64_t    u;
00073         double      f;
00074         const char *s;
00075         const struct EbmlSyntax *n;
00076     } def;
00077 } EbmlSyntax;
00078 
00079 typedef struct {
00080     int nb_elem;
00081     void *elem;
00082 } EbmlList;
00083 
00084 typedef struct {
00085     int      size;
00086     uint8_t *data;
00087     int64_t  pos;
00088 } EbmlBin;
00089 
00090 typedef struct {
00091     uint64_t version;
00092     uint64_t max_size;
00093     uint64_t id_length;
00094     char    *doctype;
00095     uint64_t doctype_version;
00096 } Ebml;
00097 
00098 typedef struct {
00099     uint64_t algo;
00100     EbmlBin  settings;
00101 } MatroskaTrackCompression;
00102 
00103 typedef struct {
00104     uint64_t scope;
00105     uint64_t type;
00106     MatroskaTrackCompression compression;
00107 } MatroskaTrackEncoding;
00108 
00109 typedef struct {
00110     double   frame_rate;
00111     uint64_t display_width;
00112     uint64_t display_height;
00113     uint64_t pixel_width;
00114     uint64_t pixel_height;
00115     EbmlBin color_space;
00116     uint64_t stereo_mode;
00117 } MatroskaTrackVideo;
00118 
00119 typedef struct {
00120     double   samplerate;
00121     double   out_samplerate;
00122     uint64_t bitdepth;
00123     uint64_t channels;
00124 
00125     /* real audio header (extracted from extradata) */
00126     int      coded_framesize;
00127     int      sub_packet_h;
00128     int      frame_size;
00129     int      sub_packet_size;
00130     int      sub_packet_cnt;
00131     int      pkt_cnt;
00132     uint64_t buf_timecode;
00133     uint8_t *buf;
00134 } MatroskaTrackAudio;
00135 
00136 typedef struct {
00137     uint64_t uid;
00138     uint64_t type;
00139 } MatroskaTrackPlane;
00140 
00141 typedef struct {
00142     EbmlList combine_planes;
00143 } MatroskaTrackOperation;
00144 
00145 typedef struct {
00146     uint64_t num;
00147     uint64_t uid;
00148     uint64_t type;
00149     char    *name;
00150     char    *codec_id;
00151     EbmlBin  codec_priv;
00152     char    *language;
00153     double time_scale;
00154     uint64_t default_duration;
00155     uint64_t flag_default;
00156     uint64_t flag_forced;
00157     MatroskaTrackVideo video;
00158     MatroskaTrackAudio audio;
00159     MatroskaTrackOperation operation;
00160     EbmlList encodings;
00161 
00162     AVStream *stream;
00163     int64_t end_timecode;
00164     int ms_compat;
00165 } MatroskaTrack;
00166 
00167 typedef struct {
00168     uint64_t uid;
00169     char *filename;
00170     char *mime;
00171     EbmlBin bin;
00172 
00173     AVStream *stream;
00174 } MatroskaAttachement;
00175 
00176 typedef struct {
00177     uint64_t start;
00178     uint64_t end;
00179     uint64_t uid;
00180     char    *title;
00181 
00182     AVChapter *chapter;
00183 } MatroskaChapter;
00184 
00185 typedef struct {
00186     uint64_t track;
00187     uint64_t pos;
00188 } MatroskaIndexPos;
00189 
00190 typedef struct {
00191     uint64_t time;
00192     EbmlList pos;
00193 } MatroskaIndex;
00194 
00195 typedef struct {
00196     char *name;
00197     char *string;
00198     char *lang;
00199     uint64_t def;
00200     EbmlList sub;
00201 } MatroskaTag;
00202 
00203 typedef struct {
00204     char    *type;
00205     uint64_t typevalue;
00206     uint64_t trackuid;
00207     uint64_t chapteruid;
00208     uint64_t attachuid;
00209 } MatroskaTagTarget;
00210 
00211 typedef struct {
00212     MatroskaTagTarget target;
00213     EbmlList tag;
00214 } MatroskaTags;
00215 
00216 typedef struct {
00217     uint64_t id;
00218     uint64_t pos;
00219 } MatroskaSeekhead;
00220 
00221 typedef struct {
00222     uint64_t start;
00223     uint64_t length;
00224 } MatroskaLevel;
00225 
00226 typedef struct {
00227     uint64_t timecode;
00228     EbmlList blocks;
00229 } MatroskaCluster;
00230 
00231 typedef struct {
00232     AVFormatContext *ctx;
00233 
00234     /* EBML stuff */
00235     int num_levels;
00236     MatroskaLevel levels[EBML_MAX_DEPTH];
00237     int level_up;
00238     uint32_t current_id;
00239 
00240     uint64_t time_scale;
00241     double   duration;
00242     char    *title;
00243     EbmlBin date_utc;
00244     EbmlList tracks;
00245     EbmlList attachments;
00246     EbmlList chapters;
00247     EbmlList index;
00248     EbmlList tags;
00249     EbmlList seekhead;
00250 
00251     /* byte position of the segment inside the stream */
00252     int64_t segment_start;
00253 
00254     /* the packet queue */
00255     AVPacket **packets;
00256     int num_packets;
00257     AVPacket *prev_pkt;
00258 
00259     int done;
00260 
00261     /* What to skip before effectively reading a packet. */
00262     int skip_to_keyframe;
00263     uint64_t skip_to_timecode;
00264 
00265     /* File has a CUES element, but we defer parsing until it is needed. */
00266     int cues_parsing_deferred;
00267 
00268     int current_cluster_num_blocks;
00269     int64_t current_cluster_pos;
00270     MatroskaCluster current_cluster;
00271 
00272     /* File has SSA subtitles which prevent incremental cluster parsing. */
00273     int contains_ssa;
00274 } MatroskaDemuxContext;
00275 
00276 typedef struct {
00277     uint64_t duration;
00278     int64_t  reference;
00279     uint64_t non_simple;
00280     EbmlBin  bin;
00281 } MatroskaBlock;
00282 
00283 static EbmlSyntax ebml_header[] = {
00284     { EBML_ID_EBMLREADVERSION,        EBML_UINT, 0, offsetof(Ebml,version), {.u=EBML_VERSION} },
00285     { EBML_ID_EBMLMAXSIZELENGTH,      EBML_UINT, 0, offsetof(Ebml,max_size), {.u=8} },
00286     { EBML_ID_EBMLMAXIDLENGTH,        EBML_UINT, 0, offsetof(Ebml,id_length), {.u=4} },
00287     { EBML_ID_DOCTYPE,                EBML_STR,  0, offsetof(Ebml,doctype), {.s="(none)"} },
00288     { EBML_ID_DOCTYPEREADVERSION,     EBML_UINT, 0, offsetof(Ebml,doctype_version), {.u=1} },
00289     { EBML_ID_EBMLVERSION,            EBML_NONE },
00290     { EBML_ID_DOCTYPEVERSION,         EBML_NONE },
00291     { 0 }
00292 };
00293 
00294 static EbmlSyntax ebml_syntax[] = {
00295     { EBML_ID_HEADER,                 EBML_NEST, 0, 0, {.n=ebml_header} },
00296     { 0 }
00297 };
00298 
00299 static EbmlSyntax matroska_info[] = {
00300     { MATROSKA_ID_TIMECODESCALE,      EBML_UINT,  0, offsetof(MatroskaDemuxContext,time_scale), {.u=1000000} },
00301     { MATROSKA_ID_DURATION,           EBML_FLOAT, 0, offsetof(MatroskaDemuxContext,duration) },
00302     { MATROSKA_ID_TITLE,              EBML_UTF8,  0, offsetof(MatroskaDemuxContext,title) },
00303     { MATROSKA_ID_WRITINGAPP,         EBML_NONE },
00304     { MATROSKA_ID_MUXINGAPP,          EBML_NONE },
00305     { MATROSKA_ID_DATEUTC,            EBML_BIN,  0, offsetof(MatroskaDemuxContext,date_utc) },
00306     { MATROSKA_ID_SEGMENTUID,         EBML_NONE },
00307     { 0 }
00308 };
00309 
00310 static EbmlSyntax matroska_track_video[] = {
00311     { MATROSKA_ID_VIDEOFRAMERATE,     EBML_FLOAT,0, offsetof(MatroskaTrackVideo,frame_rate) },
00312     { MATROSKA_ID_VIDEODISPLAYWIDTH,  EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_width) },
00313     { MATROSKA_ID_VIDEODISPLAYHEIGHT, EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_height) },
00314     { MATROSKA_ID_VIDEOPIXELWIDTH,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_width) },
00315     { MATROSKA_ID_VIDEOPIXELHEIGHT,   EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_height) },
00316     { MATROSKA_ID_VIDEOCOLORSPACE,    EBML_BIN,  0, offsetof(MatroskaTrackVideo,color_space) },
00317     { MATROSKA_ID_VIDEOSTEREOMODE,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,stereo_mode) },
00318     { MATROSKA_ID_VIDEOPIXELCROPB,    EBML_NONE },
00319     { MATROSKA_ID_VIDEOPIXELCROPT,    EBML_NONE },
00320     { MATROSKA_ID_VIDEOPIXELCROPL,    EBML_NONE },
00321     { MATROSKA_ID_VIDEOPIXELCROPR,    EBML_NONE },
00322     { MATROSKA_ID_VIDEODISPLAYUNIT,   EBML_NONE },
00323     { MATROSKA_ID_VIDEOFLAGINTERLACED,EBML_NONE },
00324     { MATROSKA_ID_VIDEOASPECTRATIO,   EBML_NONE },
00325     { 0 }
00326 };
00327 
00328 static EbmlSyntax matroska_track_audio[] = {
00329     { MATROSKA_ID_AUDIOSAMPLINGFREQ,  EBML_FLOAT,0, offsetof(MatroskaTrackAudio,samplerate), {.f=8000.0} },
00330     { MATROSKA_ID_AUDIOOUTSAMPLINGFREQ,EBML_FLOAT,0,offsetof(MatroskaTrackAudio,out_samplerate) },
00331     { MATROSKA_ID_AUDIOBITDEPTH,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,bitdepth) },
00332     { MATROSKA_ID_AUDIOCHANNELS,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,channels), {.u=1} },
00333     { 0 }
00334 };
00335 
00336 static EbmlSyntax matroska_track_encoding_compression[] = {
00337     { MATROSKA_ID_ENCODINGCOMPALGO,   EBML_UINT, 0, offsetof(MatroskaTrackCompression,algo), {.u=0} },
00338     { MATROSKA_ID_ENCODINGCOMPSETTINGS,EBML_BIN, 0, offsetof(MatroskaTrackCompression,settings) },
00339     { 0 }
00340 };
00341 
00342 static EbmlSyntax matroska_track_encoding[] = {
00343     { MATROSKA_ID_ENCODINGSCOPE,      EBML_UINT, 0, offsetof(MatroskaTrackEncoding,scope), {.u=1} },
00344     { MATROSKA_ID_ENCODINGTYPE,       EBML_UINT, 0, offsetof(MatroskaTrackEncoding,type), {.u=0} },
00345     { MATROSKA_ID_ENCODINGCOMPRESSION,EBML_NEST, 0, offsetof(MatroskaTrackEncoding,compression), {.n=matroska_track_encoding_compression} },
00346     { MATROSKA_ID_ENCODINGORDER,      EBML_NONE },
00347     { 0 }
00348 };
00349 
00350 static EbmlSyntax matroska_track_encodings[] = {
00351     { MATROSKA_ID_TRACKCONTENTENCODING, EBML_NEST, sizeof(MatroskaTrackEncoding), offsetof(MatroskaTrack,encodings), {.n=matroska_track_encoding} },
00352     { 0 }
00353 };
00354 
00355 static EbmlSyntax matroska_track_plane[] = {
00356     { MATROSKA_ID_TRACKPLANEUID,  EBML_UINT, 0, offsetof(MatroskaTrackPlane,uid) },
00357     { MATROSKA_ID_TRACKPLANETYPE, EBML_UINT, 0, offsetof(MatroskaTrackPlane,type) },
00358     { 0 }
00359 };
00360 
00361 static EbmlSyntax matroska_track_combine_planes[] = {
00362     { MATROSKA_ID_TRACKPLANE, EBML_NEST, sizeof(MatroskaTrackPlane), offsetof(MatroskaTrackOperation,combine_planes), {.n=matroska_track_plane} },
00363     { 0 }
00364 };
00365 
00366 static EbmlSyntax matroska_track_operation[] = {
00367     { MATROSKA_ID_TRACKCOMBINEPLANES, EBML_NEST, 0, 0, {.n=matroska_track_combine_planes} },
00368     { 0 }
00369 };
00370 
00371 static EbmlSyntax matroska_track[] = {
00372     { MATROSKA_ID_TRACKNUMBER,          EBML_UINT, 0, offsetof(MatroskaTrack,num) },
00373     { MATROSKA_ID_TRACKNAME,            EBML_UTF8, 0, offsetof(MatroskaTrack,name) },
00374     { MATROSKA_ID_TRACKUID,             EBML_UINT, 0, offsetof(MatroskaTrack,uid) },
00375     { MATROSKA_ID_TRACKTYPE,            EBML_UINT, 0, offsetof(MatroskaTrack,type) },
00376     { MATROSKA_ID_CODECID,              EBML_STR,  0, offsetof(MatroskaTrack,codec_id) },
00377     { MATROSKA_ID_CODECPRIVATE,         EBML_BIN,  0, offsetof(MatroskaTrack,codec_priv) },
00378     { MATROSKA_ID_TRACKLANGUAGE,        EBML_UTF8, 0, offsetof(MatroskaTrack,language), {.s="eng"} },
00379     { MATROSKA_ID_TRACKDEFAULTDURATION, EBML_UINT, 0, offsetof(MatroskaTrack,default_duration) },
00380     { MATROSKA_ID_TRACKTIMECODESCALE,   EBML_FLOAT,0, offsetof(MatroskaTrack,time_scale), {.f=1.0} },
00381     { MATROSKA_ID_TRACKFLAGDEFAULT,     EBML_UINT, 0, offsetof(MatroskaTrack,flag_default), {.u=1} },
00382     { MATROSKA_ID_TRACKFLAGFORCED,      EBML_UINT, 0, offsetof(MatroskaTrack,flag_forced), {.u=0} },
00383     { MATROSKA_ID_TRACKVIDEO,           EBML_NEST, 0, offsetof(MatroskaTrack,video), {.n=matroska_track_video} },
00384     { MATROSKA_ID_TRACKAUDIO,           EBML_NEST, 0, offsetof(MatroskaTrack,audio), {.n=matroska_track_audio} },
00385     { MATROSKA_ID_TRACKOPERATION,       EBML_NEST, 0, offsetof(MatroskaTrack,operation), {.n=matroska_track_operation} },
00386     { MATROSKA_ID_TRACKCONTENTENCODINGS,EBML_NEST, 0, 0, {.n=matroska_track_encodings} },
00387     { MATROSKA_ID_TRACKFLAGENABLED,     EBML_NONE },
00388     { MATROSKA_ID_TRACKFLAGLACING,      EBML_NONE },
00389     { MATROSKA_ID_CODECNAME,            EBML_NONE },
00390     { MATROSKA_ID_CODECDECODEALL,       EBML_NONE },
00391     { MATROSKA_ID_CODECINFOURL,         EBML_NONE },
00392     { MATROSKA_ID_CODECDOWNLOADURL,     EBML_NONE },
00393     { MATROSKA_ID_TRACKMINCACHE,        EBML_NONE },
00394     { MATROSKA_ID_TRACKMAXCACHE,        EBML_NONE },
00395     { MATROSKA_ID_TRACKMAXBLKADDID,     EBML_NONE },
00396     { 0 }
00397 };
00398 
00399 static EbmlSyntax matroska_tracks[] = {
00400     { MATROSKA_ID_TRACKENTRY,         EBML_NEST, sizeof(MatroskaTrack), offsetof(MatroskaDemuxContext,tracks), {.n=matroska_track} },
00401     { 0 }
00402 };
00403 
00404 static EbmlSyntax matroska_attachment[] = {
00405     { MATROSKA_ID_FILEUID,            EBML_UINT, 0, offsetof(MatroskaAttachement,uid) },
00406     { MATROSKA_ID_FILENAME,           EBML_UTF8, 0, offsetof(MatroskaAttachement,filename) },
00407     { MATROSKA_ID_FILEMIMETYPE,       EBML_STR,  0, offsetof(MatroskaAttachement,mime) },
00408     { MATROSKA_ID_FILEDATA,           EBML_BIN,  0, offsetof(MatroskaAttachement,bin) },
00409     { MATROSKA_ID_FILEDESC,           EBML_NONE },
00410     { 0 }
00411 };
00412 
00413 static EbmlSyntax matroska_attachments[] = {
00414     { MATROSKA_ID_ATTACHEDFILE,       EBML_NEST, sizeof(MatroskaAttachement), offsetof(MatroskaDemuxContext,attachments), {.n=matroska_attachment} },
00415     { 0 }
00416 };
00417 
00418 static EbmlSyntax matroska_chapter_display[] = {
00419     { MATROSKA_ID_CHAPSTRING,         EBML_UTF8, 0, offsetof(MatroskaChapter,title) },
00420     { MATROSKA_ID_CHAPLANG,           EBML_NONE },
00421     { 0 }
00422 };
00423 
00424 static EbmlSyntax matroska_chapter_entry[] = {
00425     { MATROSKA_ID_CHAPTERTIMESTART,   EBML_UINT, 0, offsetof(MatroskaChapter,start), {.u=AV_NOPTS_VALUE} },
00426     { MATROSKA_ID_CHAPTERTIMEEND,     EBML_UINT, 0, offsetof(MatroskaChapter,end), {.u=AV_NOPTS_VALUE} },
00427     { MATROSKA_ID_CHAPTERUID,         EBML_UINT, 0, offsetof(MatroskaChapter,uid) },
00428     { MATROSKA_ID_CHAPTERDISPLAY,     EBML_NEST, 0, 0, {.n=matroska_chapter_display} },
00429     { MATROSKA_ID_CHAPTERFLAGHIDDEN,  EBML_NONE },
00430     { MATROSKA_ID_CHAPTERFLAGENABLED, EBML_NONE },
00431     { MATROSKA_ID_CHAPTERPHYSEQUIV,   EBML_NONE },
00432     { MATROSKA_ID_CHAPTERATOM,        EBML_NONE },
00433     { 0 }
00434 };
00435 
00436 static EbmlSyntax matroska_chapter[] = {
00437     { MATROSKA_ID_CHAPTERATOM,        EBML_NEST, sizeof(MatroskaChapter), offsetof(MatroskaDemuxContext,chapters), {.n=matroska_chapter_entry} },
00438     { MATROSKA_ID_EDITIONUID,         EBML_NONE },
00439     { MATROSKA_ID_EDITIONFLAGHIDDEN,  EBML_NONE },
00440     { MATROSKA_ID_EDITIONFLAGDEFAULT, EBML_NONE },
00441     { MATROSKA_ID_EDITIONFLAGORDERED, EBML_NONE },
00442     { 0 }
00443 };
00444 
00445 static EbmlSyntax matroska_chapters[] = {
00446     { MATROSKA_ID_EDITIONENTRY,       EBML_NEST, 0, 0, {.n=matroska_chapter} },
00447     { 0 }
00448 };
00449 
00450 static EbmlSyntax matroska_index_pos[] = {
00451     { MATROSKA_ID_CUETRACK,           EBML_UINT, 0, offsetof(MatroskaIndexPos,track) },
00452     { MATROSKA_ID_CUECLUSTERPOSITION, EBML_UINT, 0, offsetof(MatroskaIndexPos,pos)   },
00453     { MATROSKA_ID_CUEBLOCKNUMBER,     EBML_NONE },
00454     { 0 }
00455 };
00456 
00457 static EbmlSyntax matroska_index_entry[] = {
00458     { MATROSKA_ID_CUETIME,            EBML_UINT, 0, offsetof(MatroskaIndex,time) },
00459     { MATROSKA_ID_CUETRACKPOSITION,   EBML_NEST, sizeof(MatroskaIndexPos), offsetof(MatroskaIndex,pos), {.n=matroska_index_pos} },
00460     { 0 }
00461 };
00462 
00463 static EbmlSyntax matroska_index[] = {
00464     { MATROSKA_ID_POINTENTRY,         EBML_NEST, sizeof(MatroskaIndex), offsetof(MatroskaDemuxContext,index), {.n=matroska_index_entry} },
00465     { 0 }
00466 };
00467 
00468 static EbmlSyntax matroska_simpletag[] = {
00469     { MATROSKA_ID_TAGNAME,            EBML_UTF8, 0, offsetof(MatroskaTag,name) },
00470     { MATROSKA_ID_TAGSTRING,          EBML_UTF8, 0, offsetof(MatroskaTag,string) },
00471     { MATROSKA_ID_TAGLANG,            EBML_STR,  0, offsetof(MatroskaTag,lang), {.s="und"} },
00472     { MATROSKA_ID_TAGDEFAULT,         EBML_UINT, 0, offsetof(MatroskaTag,def) },
00473     { MATROSKA_ID_TAGDEFAULT_BUG,     EBML_UINT, 0, offsetof(MatroskaTag,def) },
00474     { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTag,sub), {.n=matroska_simpletag} },
00475     { 0 }
00476 };
00477 
00478 static EbmlSyntax matroska_tagtargets[] = {
00479     { MATROSKA_ID_TAGTARGETS_TYPE,      EBML_STR,  0, offsetof(MatroskaTagTarget,type) },
00480     { MATROSKA_ID_TAGTARGETS_TYPEVALUE, EBML_UINT, 0, offsetof(MatroskaTagTarget,typevalue), {.u=50} },
00481     { MATROSKA_ID_TAGTARGETS_TRACKUID,  EBML_UINT, 0, offsetof(MatroskaTagTarget,trackuid) },
00482     { MATROSKA_ID_TAGTARGETS_CHAPTERUID,EBML_UINT, 0, offsetof(MatroskaTagTarget,chapteruid) },
00483     { MATROSKA_ID_TAGTARGETS_ATTACHUID, EBML_UINT, 0, offsetof(MatroskaTagTarget,attachuid) },
00484     { 0 }
00485 };
00486 
00487 static EbmlSyntax matroska_tag[] = {
00488     { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTags,tag), {.n=matroska_simpletag} },
00489     { MATROSKA_ID_TAGTARGETS,         EBML_NEST, 0, offsetof(MatroskaTags,target), {.n=matroska_tagtargets} },
00490     { 0 }
00491 };
00492 
00493 static EbmlSyntax matroska_tags[] = {
00494     { MATROSKA_ID_TAG,                EBML_NEST, sizeof(MatroskaTags), offsetof(MatroskaDemuxContext,tags), {.n=matroska_tag} },
00495     { 0 }
00496 };
00497 
00498 static EbmlSyntax matroska_seekhead_entry[] = {
00499     { MATROSKA_ID_SEEKID,             EBML_UINT, 0, offsetof(MatroskaSeekhead,id) },
00500     { MATROSKA_ID_SEEKPOSITION,       EBML_UINT, 0, offsetof(MatroskaSeekhead,pos), {.u=-1} },
00501     { 0 }
00502 };
00503 
00504 static EbmlSyntax matroska_seekhead[] = {
00505     { MATROSKA_ID_SEEKENTRY,          EBML_NEST, sizeof(MatroskaSeekhead), offsetof(MatroskaDemuxContext,seekhead), {.n=matroska_seekhead_entry} },
00506     { 0 }
00507 };
00508 
00509 static EbmlSyntax matroska_segment[] = {
00510     { MATROSKA_ID_INFO,           EBML_NEST, 0, 0, {.n=matroska_info       } },
00511     { MATROSKA_ID_TRACKS,         EBML_NEST, 0, 0, {.n=matroska_tracks     } },
00512     { MATROSKA_ID_ATTACHMENTS,    EBML_NEST, 0, 0, {.n=matroska_attachments} },
00513     { MATROSKA_ID_CHAPTERS,       EBML_NEST, 0, 0, {.n=matroska_chapters   } },
00514     { MATROSKA_ID_CUES,           EBML_NEST, 0, 0, {.n=matroska_index      } },
00515     { MATROSKA_ID_TAGS,           EBML_NEST, 0, 0, {.n=matroska_tags       } },
00516     { MATROSKA_ID_SEEKHEAD,       EBML_NEST, 0, 0, {.n=matroska_seekhead   } },
00517     { MATROSKA_ID_CLUSTER,        EBML_STOP },
00518     { 0 }
00519 };
00520 
00521 static EbmlSyntax matroska_segments[] = {
00522     { MATROSKA_ID_SEGMENT,        EBML_NEST, 0, 0, {.n=matroska_segment    } },
00523     { 0 }
00524 };
00525 
00526 static EbmlSyntax matroska_blockgroup[] = {
00527     { MATROSKA_ID_BLOCK,          EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
00528     { MATROSKA_ID_SIMPLEBLOCK,    EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
00529     { MATROSKA_ID_BLOCKDURATION,  EBML_UINT, 0, offsetof(MatroskaBlock,duration) },
00530     { MATROSKA_ID_BLOCKREFERENCE, EBML_UINT, 0, offsetof(MatroskaBlock,reference) },
00531     { 1,                          EBML_UINT, 0, offsetof(MatroskaBlock,non_simple), {.u=1} },
00532     { 0 }
00533 };
00534 
00535 static EbmlSyntax matroska_cluster[] = {
00536     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
00537     { MATROSKA_ID_BLOCKGROUP,     EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
00538     { MATROSKA_ID_SIMPLEBLOCK,    EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
00539     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
00540     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
00541     { 0 }
00542 };
00543 
00544 static EbmlSyntax matroska_clusters[] = {
00545     { MATROSKA_ID_CLUSTER,        EBML_NEST, 0, 0, {.n=matroska_cluster} },
00546     { MATROSKA_ID_INFO,           EBML_NONE },
00547     { MATROSKA_ID_CUES,           EBML_NONE },
00548     { MATROSKA_ID_TAGS,           EBML_NONE },
00549     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
00550     { 0 }
00551 };
00552 
00553 static EbmlSyntax matroska_cluster_incremental_parsing[] = {
00554     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
00555     { MATROSKA_ID_BLOCKGROUP,     EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
00556     { MATROSKA_ID_SIMPLEBLOCK,    EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
00557     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
00558     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
00559     { MATROSKA_ID_INFO,           EBML_NONE },
00560     { MATROSKA_ID_CUES,           EBML_NONE },
00561     { MATROSKA_ID_TAGS,           EBML_NONE },
00562     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
00563     { MATROSKA_ID_CLUSTER,        EBML_STOP },
00564     { 0 }
00565 };
00566 
00567 static EbmlSyntax matroska_cluster_incremental[] = {
00568     { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
00569     { MATROSKA_ID_BLOCKGROUP,     EBML_STOP },
00570     { MATROSKA_ID_SIMPLEBLOCK,    EBML_STOP },
00571     { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
00572     { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
00573     { 0 }
00574 };
00575 
00576 static EbmlSyntax matroska_clusters_incremental[] = {
00577     { MATROSKA_ID_CLUSTER,        EBML_NEST, 0, 0, {.n=matroska_cluster_incremental} },
00578     { MATROSKA_ID_INFO,           EBML_NONE },
00579     { MATROSKA_ID_CUES,           EBML_NONE },
00580     { MATROSKA_ID_TAGS,           EBML_NONE },
00581     { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
00582     { 0 }
00583 };
00584 
00585 static const char *const matroska_doctypes[] = { "matroska", "webm" };
00586 
00587 static int matroska_resync(MatroskaDemuxContext *matroska, int64_t last_pos)
00588 {
00589     AVIOContext *pb = matroska->ctx->pb;
00590     uint32_t id;
00591     matroska->current_id = 0;
00592     matroska->num_levels = 0;
00593 
00594     // seek to next position to resync from
00595     if (avio_seek(pb, last_pos + 1, SEEK_SET) < 0 || avio_tell(pb) <= last_pos)
00596         goto eof;
00597 
00598     id = avio_rb32(pb);
00599 
00600     // try to find a toplevel element
00601     while (!url_feof(pb)) {
00602         if (id == MATROSKA_ID_INFO || id == MATROSKA_ID_TRACKS ||
00603             id == MATROSKA_ID_CUES || id == MATROSKA_ID_TAGS ||
00604             id == MATROSKA_ID_SEEKHEAD || id == MATROSKA_ID_ATTACHMENTS ||
00605             id == MATROSKA_ID_CLUSTER || id == MATROSKA_ID_CHAPTERS)
00606         {
00607             matroska->current_id = id;
00608             return 0;
00609         }
00610         id = (id << 8) | avio_r8(pb);
00611     }
00612 eof:
00613     matroska->done = 1;
00614     return AVERROR_EOF;
00615 }
00616 
00617 /*
00618  * Return: Whether we reached the end of a level in the hierarchy or not.
00619  */
00620 static int ebml_level_end(MatroskaDemuxContext *matroska)
00621 {
00622     AVIOContext *pb = matroska->ctx->pb;
00623     int64_t pos = avio_tell(pb);
00624 
00625     if (matroska->num_levels > 0) {
00626         MatroskaLevel *level = &matroska->levels[matroska->num_levels - 1];
00627         if (pos - level->start >= level->length || matroska->current_id) {
00628             matroska->num_levels--;
00629             return 1;
00630         }
00631     }
00632     return 0;
00633 }
00634 
00635 /*
00636  * Read: an "EBML number", which is defined as a variable-length
00637  * array of bytes. The first byte indicates the length by giving a
00638  * number of 0-bits followed by a one. The position of the first
00639  * "one" bit inside the first byte indicates the length of this
00640  * number.
00641  * Returns: number of bytes read, < 0 on error
00642  */
00643 static int ebml_read_num(MatroskaDemuxContext *matroska, AVIOContext *pb,
00644                          int max_size, uint64_t *number)
00645 {
00646     int read = 1, n = 1;
00647     uint64_t total = 0;
00648 
00649     /* The first byte tells us the length in bytes - avio_r8() can normally
00650      * return 0, but since that's not a valid first ebmlID byte, we can
00651      * use it safely here to catch EOS. */
00652     if (!(total = avio_r8(pb))) {
00653         /* we might encounter EOS here */
00654         if (!url_feof(pb)) {
00655             int64_t pos = avio_tell(pb);
00656             av_log(matroska->ctx, AV_LOG_ERROR,
00657                    "Read error at pos. %"PRIu64" (0x%"PRIx64")\n",
00658                    pos, pos);
00659         }
00660         return AVERROR(EIO); /* EOS or actual I/O error */
00661     }
00662 
00663     /* get the length of the EBML number */
00664     read = 8 - ff_log2_tab[total];
00665     if (read > max_size) {
00666         int64_t pos = avio_tell(pb) - 1;
00667         av_log(matroska->ctx, AV_LOG_ERROR,
00668                "Invalid EBML number size tag 0x%02x at pos %"PRIu64" (0x%"PRIx64")\n",
00669                (uint8_t) total, pos, pos);
00670         return AVERROR_INVALIDDATA;
00671     }
00672 
00673     /* read out length */
00674     total ^= 1 << ff_log2_tab[total];
00675     while (n++ < read)
00676         total = (total << 8) | avio_r8(pb);
00677 
00678     *number = total;
00679 
00680     return read;
00681 }
00682 
00688 static int ebml_read_length(MatroskaDemuxContext *matroska, AVIOContext *pb,
00689                             uint64_t *number)
00690 {
00691     int res = ebml_read_num(matroska, pb, 8, number);
00692     if (res > 0 && *number + 1 == 1ULL << (7 * res))
00693         *number = 0xffffffffffffffULL;
00694     return res;
00695 }
00696 
00697 /*
00698  * Read the next element as an unsigned int.
00699  * 0 is success, < 0 is failure.
00700  */
00701 static int ebml_read_uint(AVIOContext *pb, int size, uint64_t *num)
00702 {
00703     int n = 0;
00704 
00705     if (size > 8)
00706         return AVERROR_INVALIDDATA;
00707 
00708     /* big-endian ordering; build up number */
00709     *num = 0;
00710     while (n++ < size)
00711         *num = (*num << 8) | avio_r8(pb);
00712 
00713     return 0;
00714 }
00715 
00716 /*
00717  * Read the next element as a float.
00718  * 0 is success, < 0 is failure.
00719  */
00720 static int ebml_read_float(AVIOContext *pb, int size, double *num)
00721 {
00722     if (size == 0) {
00723         *num = 0;
00724     } else if (size == 4) {
00725         *num = av_int2float(avio_rb32(pb));
00726     } else if (size == 8){
00727         *num = av_int2double(avio_rb64(pb));
00728     } else
00729         return AVERROR_INVALIDDATA;
00730 
00731     return 0;
00732 }
00733 
00734 /*
00735  * Read the next element as an ASCII string.
00736  * 0 is success, < 0 is failure.
00737  */
00738 static int ebml_read_ascii(AVIOContext *pb, int size, char **str)
00739 {
00740     char *res;
00741 
00742     /* EBML strings are usually not 0-terminated, so we allocate one
00743      * byte more, read the string and NULL-terminate it ourselves. */
00744     if (!(res = av_malloc(size + 1)))
00745         return AVERROR(ENOMEM);
00746     if (avio_read(pb, (uint8_t *) res, size) != size) {
00747         av_free(res);
00748         return AVERROR(EIO);
00749     }
00750     (res)[size] = '\0';
00751     av_free(*str);
00752     *str = res;
00753 
00754     return 0;
00755 }
00756 
00757 /*
00758  * Read the next element as binary data.
00759  * 0 is success, < 0 is failure.
00760  */
00761 static int ebml_read_binary(AVIOContext *pb, int length, EbmlBin *bin)
00762 {
00763     av_free(bin->data);
00764     if (!(bin->data = av_malloc(length)))
00765         return AVERROR(ENOMEM);
00766 
00767     bin->size = length;
00768     bin->pos  = avio_tell(pb);
00769     if (avio_read(pb, bin->data, length) != length) {
00770         av_freep(&bin->data);
00771         return AVERROR(EIO);
00772     }
00773 
00774     return 0;
00775 }
00776 
00777 /*
00778  * Read the next element, but only the header. The contents
00779  * are supposed to be sub-elements which can be read separately.
00780  * 0 is success, < 0 is failure.
00781  */
00782 static int ebml_read_master(MatroskaDemuxContext *matroska, uint64_t length)
00783 {
00784     AVIOContext *pb = matroska->ctx->pb;
00785     MatroskaLevel *level;
00786 
00787     if (matroska->num_levels >= EBML_MAX_DEPTH) {
00788         av_log(matroska->ctx, AV_LOG_ERROR,
00789                "File moves beyond max. allowed depth (%d)\n", EBML_MAX_DEPTH);
00790         return AVERROR(ENOSYS);
00791     }
00792 
00793     level = &matroska->levels[matroska->num_levels++];
00794     level->start = avio_tell(pb);
00795     level->length = length;
00796 
00797     return 0;
00798 }
00799 
00800 /*
00801  * Read signed/unsigned "EBML" numbers.
00802  * Return: number of bytes processed, < 0 on error
00803  */
00804 static int matroska_ebmlnum_uint(MatroskaDemuxContext *matroska,
00805                                  uint8_t *data, uint32_t size, uint64_t *num)
00806 {
00807     AVIOContext pb;
00808     ffio_init_context(&pb, data, size, 0, NULL, NULL, NULL, NULL);
00809     return ebml_read_num(matroska, &pb, FFMIN(size, 8), num);
00810 }
00811 
00812 /*
00813  * Same as above, but signed.
00814  */
00815 static int matroska_ebmlnum_sint(MatroskaDemuxContext *matroska,
00816                                  uint8_t *data, uint32_t size, int64_t *num)
00817 {
00818     uint64_t unum;
00819     int res;
00820 
00821     /* read as unsigned number first */
00822     if ((res = matroska_ebmlnum_uint(matroska, data, size, &unum)) < 0)
00823         return res;
00824 
00825     /* make signed (weird way) */
00826     *num = unum - ((1LL << (7*res - 1)) - 1);
00827 
00828     return res;
00829 }
00830 
00831 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
00832                            EbmlSyntax *syntax, void *data);
00833 
00834 static int ebml_parse_id(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
00835                          uint32_t id, void *data)
00836 {
00837     int i;
00838     for (i=0; syntax[i].id; i++)
00839         if (id == syntax[i].id)
00840             break;
00841     if (!syntax[i].id && id == MATROSKA_ID_CLUSTER &&
00842         matroska->num_levels > 0 &&
00843         matroska->levels[matroska->num_levels-1].length == 0xffffffffffffff)
00844         return 0;  // we reached the end of an unknown size cluster
00845     if (!syntax[i].id && id != EBML_ID_VOID && id != EBML_ID_CRC32)
00846         av_log(matroska->ctx, AV_LOG_INFO, "Unknown entry 0x%X\n", id);
00847     return ebml_parse_elem(matroska, &syntax[i], data);
00848 }
00849 
00850 static int ebml_parse(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
00851                       void *data)
00852 {
00853     if (!matroska->current_id) {
00854         uint64_t id;
00855         int res = ebml_read_num(matroska, matroska->ctx->pb, 4, &id);
00856         if (res < 0)
00857             return res;
00858         matroska->current_id = id | 1 << 7*res;
00859     }
00860     return ebml_parse_id(matroska, syntax, matroska->current_id, data);
00861 }
00862 
00863 static int ebml_parse_nest(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
00864                            void *data)
00865 {
00866     int i, res = 0;
00867 
00868     for (i=0; syntax[i].id; i++)
00869         switch (syntax[i].type) {
00870         case EBML_UINT:
00871             *(uint64_t *)((char *)data+syntax[i].data_offset) = syntax[i].def.u;
00872             break;
00873         case EBML_FLOAT:
00874             *(double   *)((char *)data+syntax[i].data_offset) = syntax[i].def.f;
00875             break;
00876         case EBML_STR:
00877         case EBML_UTF8:
00878             *(char    **)((char *)data+syntax[i].data_offset) = av_strdup(syntax[i].def.s);
00879             break;
00880         }
00881 
00882     while (!res && !ebml_level_end(matroska))
00883         res = ebml_parse(matroska, syntax, data);
00884 
00885     return res;
00886 }
00887 
00888 static int ebml_parse_elem(MatroskaDemuxContext *matroska,
00889                            EbmlSyntax *syntax, void *data)
00890 {
00891     static const uint64_t max_lengths[EBML_TYPE_COUNT] = {
00892         [EBML_UINT]  = 8,
00893         [EBML_FLOAT] = 8,
00894         // max. 16 MB for strings
00895         [EBML_STR]   = 0x1000000,
00896         [EBML_UTF8]  = 0x1000000,
00897         // max. 256 MB for binary data
00898         [EBML_BIN]   = 0x10000000,
00899         // no limits for anything else
00900     };
00901     AVIOContext *pb = matroska->ctx->pb;
00902     uint32_t id = syntax->id;
00903     uint64_t length;
00904     int res;
00905     void *newelem;
00906 
00907     data = (char *)data + syntax->data_offset;
00908     if (syntax->list_elem_size) {
00909         EbmlList *list = data;
00910         newelem = av_realloc(list->elem, (list->nb_elem+1)*syntax->list_elem_size);
00911         if (!newelem)
00912             return AVERROR(ENOMEM);
00913         list->elem = newelem;
00914         data = (char*)list->elem + list->nb_elem*syntax->list_elem_size;
00915         memset(data, 0, syntax->list_elem_size);
00916         list->nb_elem++;
00917     }
00918 
00919     if (syntax->type != EBML_PASS && syntax->type != EBML_STOP) {
00920         matroska->current_id = 0;
00921         if ((res = ebml_read_length(matroska, pb, &length)) < 0)
00922             return res;
00923         if (max_lengths[syntax->type] && length > max_lengths[syntax->type]) {
00924             av_log(matroska->ctx, AV_LOG_ERROR,
00925                    "Invalid length 0x%"PRIx64" > 0x%"PRIx64" for syntax element %i\n",
00926                    length, max_lengths[syntax->type], syntax->type);
00927             return AVERROR_INVALIDDATA;
00928         }
00929     }
00930 
00931     switch (syntax->type) {
00932     case EBML_UINT:  res = ebml_read_uint  (pb, length, data);  break;
00933     case EBML_FLOAT: res = ebml_read_float (pb, length, data);  break;
00934     case EBML_STR:
00935     case EBML_UTF8:  res = ebml_read_ascii (pb, length, data);  break;
00936     case EBML_BIN:   res = ebml_read_binary(pb, length, data);  break;
00937     case EBML_NEST:  if ((res=ebml_read_master(matroska, length)) < 0)
00938                          return res;
00939                      if (id == MATROSKA_ID_SEGMENT)
00940                          matroska->segment_start = avio_tell(matroska->ctx->pb);
00941                      return ebml_parse_nest(matroska, syntax->def.n, data);
00942     case EBML_PASS:  return ebml_parse_id(matroska, syntax->def.n, id, data);
00943     case EBML_STOP:  return 1;
00944     default:         return avio_skip(pb,length)<0 ? AVERROR(EIO) : 0;
00945     }
00946     if (res == AVERROR_INVALIDDATA)
00947         av_log(matroska->ctx, AV_LOG_ERROR, "Invalid element\n");
00948     else if (res == AVERROR(EIO))
00949         av_log(matroska->ctx, AV_LOG_ERROR, "Read error\n");
00950     return res;
00951 }
00952 
00953 static void ebml_free(EbmlSyntax *syntax, void *data)
00954 {
00955     int i, j;
00956     for (i=0; syntax[i].id; i++) {
00957         void *data_off = (char *)data + syntax[i].data_offset;
00958         switch (syntax[i].type) {
00959         case EBML_STR:
00960         case EBML_UTF8:  av_freep(data_off);                      break;
00961         case EBML_BIN:   av_freep(&((EbmlBin *)data_off)->data);  break;
00962         case EBML_NEST:
00963             if (syntax[i].list_elem_size) {
00964                 EbmlList *list = data_off;
00965                 char *ptr = list->elem;
00966                 for (j=0; j<list->nb_elem; j++, ptr+=syntax[i].list_elem_size)
00967                     ebml_free(syntax[i].def.n, ptr);
00968                 av_free(list->elem);
00969             } else
00970                 ebml_free(syntax[i].def.n, data_off);
00971         default:  break;
00972         }
00973     }
00974 }
00975 
00976 
00977 /*
00978  * Autodetecting...
00979  */
00980 static int matroska_probe(AVProbeData *p)
00981 {
00982     uint64_t total = 0;
00983     int len_mask = 0x80, size = 1, n = 1, i;
00984 
00985     /* EBML header? */
00986     if (AV_RB32(p->buf) != EBML_ID_HEADER)
00987         return 0;
00988 
00989     /* length of header */
00990     total = p->buf[4];
00991     while (size <= 8 && !(total & len_mask)) {
00992         size++;
00993         len_mask >>= 1;
00994     }
00995     if (size > 8)
00996       return 0;
00997     total &= (len_mask - 1);
00998     while (n < size)
00999         total = (total << 8) | p->buf[4 + n++];
01000 
01001     /* Does the probe data contain the whole header? */
01002     if (p->buf_size < 4 + size + total)
01003       return 0;
01004 
01005     /* The header should contain a known document type. For now,
01006      * we don't parse the whole header but simply check for the
01007      * availability of that array of characters inside the header.
01008      * Not fully fool-proof, but good enough. */
01009     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++) {
01010         int probelen = strlen(matroska_doctypes[i]);
01011         if (total < probelen)
01012             continue;
01013         for (n = 4+size; n <= 4+size+total-probelen; n++)
01014             if (!memcmp(p->buf+n, matroska_doctypes[i], probelen))
01015                 return AVPROBE_SCORE_MAX;
01016     }
01017 
01018     // probably valid EBML header but no recognized doctype
01019     return AVPROBE_SCORE_MAX/2;
01020 }
01021 
01022 static MatroskaTrack *matroska_find_track_by_num(MatroskaDemuxContext *matroska,
01023                                                  int num)
01024 {
01025     MatroskaTrack *tracks = matroska->tracks.elem;
01026     int i;
01027 
01028     for (i=0; i < matroska->tracks.nb_elem; i++)
01029         if (tracks[i].num == num)
01030             return &tracks[i];
01031 
01032     av_log(matroska->ctx, AV_LOG_ERROR, "Invalid track number %d\n", num);
01033     return NULL;
01034 }
01035 
01036 static int matroska_decode_buffer(uint8_t** buf, int* buf_size,
01037                                   MatroskaTrack *track)
01038 {
01039     MatroskaTrackEncoding *encodings = track->encodings.elem;
01040     uint8_t* data = *buf;
01041     int isize = *buf_size;
01042     uint8_t* pkt_data = NULL;
01043     uint8_t av_unused *newpktdata;
01044     int pkt_size = isize;
01045     int result = 0;
01046     int olen;
01047 
01048     if (pkt_size >= 10000000)
01049         return -1;
01050 
01051     switch (encodings[0].compression.algo) {
01052     case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP:
01053         if (encodings[0].compression.settings.size && !encodings[0].compression.settings.data) {
01054             av_log(0, AV_LOG_ERROR, "Compression size but no data in headerstrip\n");
01055             return -1;
01056         }
01057         return encodings[0].compression.settings.size;
01058     case MATROSKA_TRACK_ENCODING_COMP_LZO:
01059         do {
01060             olen = pkt_size *= 3;
01061             pkt_data = av_realloc(pkt_data, pkt_size+AV_LZO_OUTPUT_PADDING);
01062             result = av_lzo1x_decode(pkt_data, &olen, data, &isize);
01063         } while (result==AV_LZO_OUTPUT_FULL && pkt_size<10000000);
01064         if (result)
01065             goto failed;
01066         pkt_size -= olen;
01067         break;
01068 #if CONFIG_ZLIB
01069     case MATROSKA_TRACK_ENCODING_COMP_ZLIB: {
01070         z_stream zstream = {0};
01071         if (inflateInit(&zstream) != Z_OK)
01072             return -1;
01073         zstream.next_in = data;
01074         zstream.avail_in = isize;
01075         do {
01076             pkt_size *= 3;
01077             newpktdata = av_realloc(pkt_data, pkt_size);
01078             if (!newpktdata) {
01079                 inflateEnd(&zstream);
01080                 goto failed;
01081             }
01082             pkt_data = newpktdata;
01083             zstream.avail_out = pkt_size - zstream.total_out;
01084             zstream.next_out = pkt_data + zstream.total_out;
01085             if (pkt_data) {
01086                 result = inflate(&zstream, Z_NO_FLUSH);
01087             } else
01088                 result = Z_MEM_ERROR;
01089         } while (result==Z_OK && pkt_size<10000000);
01090         pkt_size = zstream.total_out;
01091         inflateEnd(&zstream);
01092         if (result != Z_STREAM_END)
01093             goto failed;
01094         break;
01095     }
01096 #endif
01097 #if CONFIG_BZLIB
01098     case MATROSKA_TRACK_ENCODING_COMP_BZLIB: {
01099         bz_stream bzstream = {0};
01100         if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
01101             return -1;
01102         bzstream.next_in = data;
01103         bzstream.avail_in = isize;
01104         do {
01105             pkt_size *= 3;
01106             newpktdata = av_realloc(pkt_data, pkt_size);
01107             if (!newpktdata) {
01108                 BZ2_bzDecompressEnd(&bzstream);
01109                 goto failed;
01110             }
01111             pkt_data = newpktdata;
01112             bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
01113             bzstream.next_out = pkt_data + bzstream.total_out_lo32;
01114             if (pkt_data) {
01115                 result = BZ2_bzDecompress(&bzstream);
01116             } else
01117                 result = BZ_MEM_ERROR;
01118         } while (result==BZ_OK && pkt_size<10000000);
01119         pkt_size = bzstream.total_out_lo32;
01120         BZ2_bzDecompressEnd(&bzstream);
01121         if (result != BZ_STREAM_END)
01122             goto failed;
01123         break;
01124     }
01125 #endif
01126     default:
01127         return -1;
01128     }
01129 
01130     *buf = pkt_data;
01131     *buf_size = pkt_size;
01132     return 0;
01133  failed:
01134     av_free(pkt_data);
01135     return -1;
01136 }
01137 
01138 static void matroska_fix_ass_packet(MatroskaDemuxContext *matroska,
01139                                     AVPacket *pkt, uint64_t display_duration)
01140 {
01141     char *line, *layer, *ptr = pkt->data, *end = ptr+pkt->size;
01142     for (; *ptr!=',' && ptr<end-1; ptr++);
01143     if (*ptr == ',')
01144         ptr++;
01145     layer = ptr;
01146     for (; *ptr!=',' && ptr<end-1; ptr++);
01147     if (*ptr == ',') {
01148         int64_t end_pts = pkt->pts + display_duration;
01149         int sc = matroska->time_scale * pkt->pts / 10000000;
01150         int ec = matroska->time_scale * end_pts  / 10000000;
01151         int sh, sm, ss, eh, em, es, len;
01152         sh = sc/360000;  sc -= 360000*sh;
01153         sm = sc/  6000;  sc -=   6000*sm;
01154         ss = sc/   100;  sc -=    100*ss;
01155         eh = ec/360000;  ec -= 360000*eh;
01156         em = ec/  6000;  ec -=   6000*em;
01157         es = ec/   100;  ec -=    100*es;
01158         *ptr++ = '\0';
01159         len = 50 + end-ptr + FF_INPUT_BUFFER_PADDING_SIZE;
01160         if (!(line = av_malloc(len)))
01161             return;
01162         snprintf(line,len,"Dialogue: %s,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s\r\n",
01163                  layer, sh, sm, ss, sc, eh, em, es, ec, ptr);
01164         av_free(pkt->data);
01165         pkt->data = line;
01166         pkt->size = strlen(line);
01167     }
01168 }
01169 
01170 static int matroska_merge_packets(AVPacket *out, AVPacket *in)
01171 {
01172     int ret = av_grow_packet(out, in->size);
01173     if (ret < 0)
01174         return ret;
01175     memcpy(out->data + out->size - in->size, in->data, in->size);
01176     av_destruct_packet(in);
01177     av_free(in);
01178     return 0;
01179 }
01180 
01181 static void matroska_convert_tag(AVFormatContext *s, EbmlList *list,
01182                                  AVDictionary **metadata, char *prefix)
01183 {
01184     MatroskaTag *tags = list->elem;
01185     char key[1024];
01186     int i;
01187 
01188     for (i=0; i < list->nb_elem; i++) {
01189         const char *lang= (tags[i].lang && strcmp(tags[i].lang, "und")) ? tags[i].lang : NULL;
01190 
01191         if (!tags[i].name) {
01192             av_log(s, AV_LOG_WARNING, "Skipping invalid tag with no TagName.\n");
01193             continue;
01194         }
01195         if (prefix)  snprintf(key, sizeof(key), "%s/%s", prefix, tags[i].name);
01196         else         av_strlcpy(key, tags[i].name, sizeof(key));
01197         if (tags[i].def || !lang) {
01198         av_dict_set(metadata, key, tags[i].string, 0);
01199         if (tags[i].sub.nb_elem)
01200             matroska_convert_tag(s, &tags[i].sub, metadata, key);
01201         }
01202         if (lang) {
01203             av_strlcat(key, "-", sizeof(key));
01204             av_strlcat(key, lang, sizeof(key));
01205             av_dict_set(metadata, key, tags[i].string, 0);
01206             if (tags[i].sub.nb_elem)
01207                 matroska_convert_tag(s, &tags[i].sub, metadata, key);
01208         }
01209     }
01210     ff_metadata_conv(metadata, NULL, ff_mkv_metadata_conv);
01211 }
01212 
01213 static void matroska_convert_tags(AVFormatContext *s)
01214 {
01215     MatroskaDemuxContext *matroska = s->priv_data;
01216     MatroskaTags *tags = matroska->tags.elem;
01217     int i, j;
01218 
01219     for (i=0; i < matroska->tags.nb_elem; i++) {
01220         if (tags[i].target.attachuid) {
01221             MatroskaAttachement *attachment = matroska->attachments.elem;
01222             for (j=0; j<matroska->attachments.nb_elem; j++)
01223                 if (attachment[j].uid == tags[i].target.attachuid
01224                     && attachment[j].stream)
01225                     matroska_convert_tag(s, &tags[i].tag,
01226                                          &attachment[j].stream->metadata, NULL);
01227         } else if (tags[i].target.chapteruid) {
01228             MatroskaChapter *chapter = matroska->chapters.elem;
01229             for (j=0; j<matroska->chapters.nb_elem; j++)
01230                 if (chapter[j].uid == tags[i].target.chapteruid
01231                     && chapter[j].chapter)
01232                     matroska_convert_tag(s, &tags[i].tag,
01233                                          &chapter[j].chapter->metadata, NULL);
01234         } else if (tags[i].target.trackuid) {
01235             MatroskaTrack *track = matroska->tracks.elem;
01236             for (j=0; j<matroska->tracks.nb_elem; j++)
01237                 if (track[j].uid == tags[i].target.trackuid && track[j].stream)
01238                     matroska_convert_tag(s, &tags[i].tag,
01239                                          &track[j].stream->metadata, NULL);
01240         } else {
01241             matroska_convert_tag(s, &tags[i].tag, &s->metadata,
01242                                  tags[i].target.type);
01243         }
01244     }
01245 }
01246 
01247 static int matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska, int idx)
01248 {
01249     EbmlList *seekhead_list = &matroska->seekhead;
01250     MatroskaSeekhead *seekhead = seekhead_list->elem;
01251     uint32_t level_up = matroska->level_up;
01252     int64_t before_pos = avio_tell(matroska->ctx->pb);
01253     uint32_t saved_id = matroska->current_id;
01254     MatroskaLevel level;
01255     int64_t offset;
01256     int ret = 0;
01257 
01258     if (idx >= seekhead_list->nb_elem
01259             || seekhead[idx].id == MATROSKA_ID_SEEKHEAD
01260             || seekhead[idx].id == MATROSKA_ID_CLUSTER)
01261         return 0;
01262 
01263     /* seek */
01264     offset = seekhead[idx].pos + matroska->segment_start;
01265     if (avio_seek(matroska->ctx->pb, offset, SEEK_SET) == offset) {
01266         /* We don't want to lose our seekhead level, so we add
01267          * a dummy. This is a crude hack. */
01268         if (matroska->num_levels == EBML_MAX_DEPTH) {
01269             av_log(matroska->ctx, AV_LOG_INFO,
01270                    "Max EBML element depth (%d) reached, "
01271                    "cannot parse further.\n", EBML_MAX_DEPTH);
01272             ret = AVERROR_INVALIDDATA;
01273         } else {
01274             level.start = 0;
01275             level.length = (uint64_t)-1;
01276             matroska->levels[matroska->num_levels] = level;
01277             matroska->num_levels++;
01278             matroska->current_id = 0;
01279 
01280             ret = ebml_parse(matroska, matroska_segment, matroska);
01281 
01282             /* remove dummy level */
01283             while (matroska->num_levels) {
01284                 uint64_t length = matroska->levels[--matroska->num_levels].length;
01285                 if (length == (uint64_t)-1)
01286                     break;
01287             }
01288         }
01289     }
01290     /* seek back */
01291     avio_seek(matroska->ctx->pb, before_pos, SEEK_SET);
01292     matroska->level_up = level_up;
01293     matroska->current_id = saved_id;
01294 
01295     return ret;
01296 }
01297 
01298 static void matroska_execute_seekhead(MatroskaDemuxContext *matroska)
01299 {
01300     EbmlList *seekhead_list = &matroska->seekhead;
01301     int64_t before_pos = avio_tell(matroska->ctx->pb);
01302     int i;
01303 
01304     // we should not do any seeking in the streaming case
01305     if (!matroska->ctx->pb->seekable ||
01306         (matroska->ctx->flags & AVFMT_FLAG_IGNIDX))
01307         return;
01308 
01309     for (i = 0; i < seekhead_list->nb_elem; i++) {
01310         MatroskaSeekhead *seekhead = seekhead_list->elem;
01311         if (seekhead[i].pos <= before_pos)
01312             continue;
01313 
01314         // defer cues parsing until we actually need cue data.
01315         if (seekhead[i].id == MATROSKA_ID_CUES) {
01316             matroska->cues_parsing_deferred = 1;
01317             continue;
01318         }
01319 
01320         if (matroska_parse_seekhead_entry(matroska, i) < 0) {
01321             // mark index as broken
01322             matroska->cues_parsing_deferred = -1;
01323             break;
01324         }
01325     }
01326 }
01327 
01328 static void matroska_add_index_entries(MatroskaDemuxContext *matroska) {
01329     EbmlList *index_list;
01330     MatroskaIndex *index;
01331     int index_scale = 1;
01332     int i, j;
01333 
01334     index_list = &matroska->index;
01335     index = index_list->elem;
01336     if (index_list->nb_elem
01337         && index[0].time > 1E14/matroska->time_scale) {
01338         av_log(matroska->ctx, AV_LOG_WARNING, "Working around broken index.\n");
01339         index_scale = matroska->time_scale;
01340     }
01341     for (i = 0; i < index_list->nb_elem; i++) {
01342         EbmlList *pos_list = &index[i].pos;
01343         MatroskaIndexPos *pos = pos_list->elem;
01344         for (j = 0; j < pos_list->nb_elem; j++) {
01345             MatroskaTrack *track = matroska_find_track_by_num(matroska, pos[j].track);
01346             if (track && track->stream)
01347                 av_add_index_entry(track->stream,
01348                                    pos[j].pos + matroska->segment_start,
01349                                    index[i].time/index_scale, 0, 0,
01350                                    AVINDEX_KEYFRAME);
01351         }
01352     }
01353 }
01354 
01355 static void matroska_parse_cues(MatroskaDemuxContext *matroska) {
01356     EbmlList *seekhead_list = &matroska->seekhead;
01357     MatroskaSeekhead *seekhead = seekhead_list->elem;
01358     int i;
01359 
01360     for (i = 0; i < seekhead_list->nb_elem; i++)
01361         if (seekhead[i].id == MATROSKA_ID_CUES)
01362             break;
01363     assert(i <= seekhead_list->nb_elem);
01364 
01365     if (matroska_parse_seekhead_entry(matroska, i) < 0)
01366        matroska->cues_parsing_deferred = -1;
01367     matroska_add_index_entries(matroska);
01368 }
01369 
01370 static int matroska_aac_profile(char *codec_id)
01371 {
01372     static const char * const aac_profiles[] = { "MAIN", "LC", "SSR" };
01373     int profile;
01374 
01375     for (profile=0; profile<FF_ARRAY_ELEMS(aac_profiles); profile++)
01376         if (strstr(codec_id, aac_profiles[profile]))
01377             break;
01378     return profile + 1;
01379 }
01380 
01381 static int matroska_aac_sri(int samplerate)
01382 {
01383     int sri;
01384 
01385     for (sri=0; sri<FF_ARRAY_ELEMS(avpriv_mpeg4audio_sample_rates); sri++)
01386         if (avpriv_mpeg4audio_sample_rates[sri] == samplerate)
01387             break;
01388     return sri;
01389 }
01390 
01391 static void matroska_metadata_creation_time(AVDictionary **metadata, int64_t date_utc)
01392 {
01393     char buffer[32];
01394     /* Convert to seconds and adjust by number of seconds between 2001-01-01 and Epoch */
01395     time_t creation_time = date_utc / 1000000000 + 978307200;
01396     struct tm *ptm = gmtime(&creation_time);
01397     if (!ptm) return;
01398     strftime(buffer, sizeof(buffer), "%Y-%m-%d %H:%M:%S", ptm);
01399     av_dict_set(metadata, "creation_time", buffer, 0);
01400 }
01401 
01402 static int matroska_read_header(AVFormatContext *s)
01403 {
01404     MatroskaDemuxContext *matroska = s->priv_data;
01405     EbmlList *attachements_list = &matroska->attachments;
01406     MatroskaAttachement *attachements;
01407     EbmlList *chapters_list = &matroska->chapters;
01408     MatroskaChapter *chapters;
01409     MatroskaTrack *tracks;
01410     uint64_t max_start = 0;
01411     int64_t pos;
01412     Ebml ebml = { 0 };
01413     AVStream *st;
01414     int i, j, k, res;
01415 
01416     matroska->ctx = s;
01417 
01418     /* First read the EBML header. */
01419     if (ebml_parse(matroska, ebml_syntax, &ebml)
01420         || ebml.version > EBML_VERSION       || ebml.max_size > sizeof(uint64_t)
01421         || ebml.id_length > sizeof(uint32_t) || ebml.doctype_version > 3 || !ebml.doctype) {
01422         av_log(matroska->ctx, AV_LOG_ERROR,
01423                "EBML header using unsupported features\n"
01424                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
01425                ebml.version, ebml.doctype, ebml.doctype_version);
01426         ebml_free(ebml_syntax, &ebml);
01427         return AVERROR_PATCHWELCOME;
01428     } else if (ebml.doctype_version == 3) {
01429         av_log(matroska->ctx, AV_LOG_WARNING,
01430                "EBML header using unsupported features\n"
01431                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
01432                ebml.version, ebml.doctype, ebml.doctype_version);
01433     }
01434     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++)
01435         if (!strcmp(ebml.doctype, matroska_doctypes[i]))
01436             break;
01437     if (i >= FF_ARRAY_ELEMS(matroska_doctypes)) {
01438         av_log(s, AV_LOG_WARNING, "Unknown EBML doctype '%s'\n", ebml.doctype);
01439     }
01440     ebml_free(ebml_syntax, &ebml);
01441 
01442     /* The next thing is a segment. */
01443     pos = avio_tell(matroska->ctx->pb);
01444     res = ebml_parse(matroska, matroska_segments, matroska);
01445     // try resyncing until we find a EBML_STOP type element.
01446     while (res != 1) {
01447         res = matroska_resync(matroska, pos);
01448         if (res < 0)
01449             return res;
01450         pos = avio_tell(matroska->ctx->pb);
01451         res = ebml_parse(matroska, matroska_segment, matroska);
01452     }
01453     matroska_execute_seekhead(matroska);
01454 
01455     if (!matroska->time_scale)
01456         matroska->time_scale = 1000000;
01457     if (matroska->duration)
01458         matroska->ctx->duration = matroska->duration * matroska->time_scale
01459                                   * 1000 / AV_TIME_BASE;
01460     av_dict_set(&s->metadata, "title", matroska->title, 0);
01461 
01462     if (matroska->date_utc.size == 8)
01463         matroska_metadata_creation_time(&s->metadata, AV_RB64(matroska->date_utc.data));
01464 
01465     tracks = matroska->tracks.elem;
01466     for (i=0; i < matroska->tracks.nb_elem; i++) {
01467         MatroskaTrack *track = &tracks[i];
01468         enum CodecID codec_id = CODEC_ID_NONE;
01469         EbmlList *encodings_list = &track->encodings;
01470         MatroskaTrackEncoding *encodings = encodings_list->elem;
01471         uint8_t *extradata = NULL;
01472         int extradata_size = 0;
01473         int extradata_offset = 0;
01474         uint32_t fourcc = 0;
01475         AVIOContext b;
01476 
01477         /* Apply some sanity checks. */
01478         if (track->type != MATROSKA_TRACK_TYPE_VIDEO &&
01479             track->type != MATROSKA_TRACK_TYPE_AUDIO &&
01480             track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
01481             av_log(matroska->ctx, AV_LOG_INFO,
01482                    "Unknown or unsupported track type %"PRIu64"\n",
01483                    track->type);
01484             continue;
01485         }
01486         if (track->codec_id == NULL)
01487             continue;
01488 
01489         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
01490             if (!track->default_duration && track->video.frame_rate > 0)
01491                 track->default_duration = 1000000000/track->video.frame_rate;
01492             if (!track->video.display_width)
01493                 track->video.display_width = track->video.pixel_width;
01494             if (!track->video.display_height)
01495                 track->video.display_height = track->video.pixel_height;
01496             if (track->video.color_space.size == 4)
01497                 fourcc = AV_RL32(track->video.color_space.data);
01498         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
01499             if (!track->audio.out_samplerate)
01500                 track->audio.out_samplerate = track->audio.samplerate;
01501         }
01502         if (encodings_list->nb_elem > 1) {
01503             av_log(matroska->ctx, AV_LOG_ERROR,
01504                    "Multiple combined encodings not supported");
01505         } else if (encodings_list->nb_elem == 1) {
01506             if (encodings[0].type ||
01507                 (encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP &&
01508 #if CONFIG_ZLIB
01509                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_ZLIB &&
01510 #endif
01511 #if CONFIG_BZLIB
01512                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_BZLIB &&
01513 #endif
01514                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_LZO)) {
01515                 encodings[0].scope = 0;
01516                 av_log(matroska->ctx, AV_LOG_ERROR,
01517                        "Unsupported encoding type");
01518             } else if (track->codec_priv.size && encodings[0].scope&2) {
01519                 uint8_t *codec_priv = track->codec_priv.data;
01520                 int offset = matroska_decode_buffer(&track->codec_priv.data,
01521                                                     &track->codec_priv.size,
01522                                                     track);
01523                 if (offset < 0) {
01524                     track->codec_priv.data = NULL;
01525                     track->codec_priv.size = 0;
01526                     av_log(matroska->ctx, AV_LOG_ERROR,
01527                            "Failed to decode codec private data\n");
01528                 } else if (offset > 0) {
01529                     track->codec_priv.data = av_malloc(track->codec_priv.size + offset);
01530                     memcpy(track->codec_priv.data,
01531                            encodings[0].compression.settings.data, offset);
01532                     memcpy(track->codec_priv.data+offset, codec_priv,
01533                            track->codec_priv.size);
01534                     track->codec_priv.size += offset;
01535                 }
01536                 if (codec_priv != track->codec_priv.data)
01537                     av_free(codec_priv);
01538             }
01539         }
01540 
01541         for(j=0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++){
01542             if(!strncmp(ff_mkv_codec_tags[j].str, track->codec_id,
01543                         strlen(ff_mkv_codec_tags[j].str))){
01544                 codec_id= ff_mkv_codec_tags[j].id;
01545                 break;
01546             }
01547         }
01548 
01549         st = track->stream = avformat_new_stream(s, NULL);
01550         if (st == NULL)
01551             return AVERROR(ENOMEM);
01552 
01553         if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC")
01554             && track->codec_priv.size >= 40
01555             && track->codec_priv.data != NULL) {
01556             track->ms_compat = 1;
01557             fourcc = AV_RL32(track->codec_priv.data + 16);
01558             codec_id = ff_codec_get_id(ff_codec_bmp_tags, fourcc);
01559             extradata_offset = 40;
01560         } else if (!strcmp(track->codec_id, "A_MS/ACM")
01561                    && track->codec_priv.size >= 14
01562                    && track->codec_priv.data != NULL) {
01563             int ret;
01564             ffio_init_context(&b, track->codec_priv.data, track->codec_priv.size,
01565                           AVIO_FLAG_READ, NULL, NULL, NULL, NULL);
01566             ret = ff_get_wav_header(&b, st->codec, track->codec_priv.size);
01567             if (ret < 0)
01568                 return ret;
01569             codec_id = st->codec->codec_id;
01570             extradata_offset = FFMIN(track->codec_priv.size, 18);
01571         } else if (!strcmp(track->codec_id, "V_QUICKTIME")
01572                    && (track->codec_priv.size >= 86)
01573                    && (track->codec_priv.data != NULL)) {
01574             fourcc = AV_RL32(track->codec_priv.data);
01575             codec_id = ff_codec_get_id(ff_codec_movvideo_tags, fourcc);
01576         } else if (codec_id == CODEC_ID_PCM_S16BE) {
01577             switch (track->audio.bitdepth) {
01578             case  8:  codec_id = CODEC_ID_PCM_U8;     break;
01579             case 24:  codec_id = CODEC_ID_PCM_S24BE;  break;
01580             case 32:  codec_id = CODEC_ID_PCM_S32BE;  break;
01581             }
01582         } else if (codec_id == CODEC_ID_PCM_S16LE) {
01583             switch (track->audio.bitdepth) {
01584             case  8:  codec_id = CODEC_ID_PCM_U8;     break;
01585             case 24:  codec_id = CODEC_ID_PCM_S24LE;  break;
01586             case 32:  codec_id = CODEC_ID_PCM_S32LE;  break;
01587             }
01588         } else if (codec_id==CODEC_ID_PCM_F32LE && track->audio.bitdepth==64) {
01589             codec_id = CODEC_ID_PCM_F64LE;
01590         } else if (codec_id == CODEC_ID_AAC && !track->codec_priv.size) {
01591             int profile = matroska_aac_profile(track->codec_id);
01592             int sri = matroska_aac_sri(track->audio.samplerate);
01593             extradata = av_mallocz(5 + FF_INPUT_BUFFER_PADDING_SIZE);
01594             if (extradata == NULL)
01595                 return AVERROR(ENOMEM);
01596             extradata[0] = (profile << 3) | ((sri&0x0E) >> 1);
01597             extradata[1] = ((sri&0x01) << 7) | (track->audio.channels<<3);
01598             if (strstr(track->codec_id, "SBR")) {
01599                 sri = matroska_aac_sri(track->audio.out_samplerate);
01600                 extradata[2] = 0x56;
01601                 extradata[3] = 0xE5;
01602                 extradata[4] = 0x80 | (sri<<3);
01603                 extradata_size = 5;
01604             } else
01605                 extradata_size = 2;
01606         } else if (codec_id == CODEC_ID_TTA) {
01607             extradata_size = 30;
01608             extradata = av_mallocz(extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
01609             if (extradata == NULL)
01610                 return AVERROR(ENOMEM);
01611             ffio_init_context(&b, extradata, extradata_size, 1,
01612                           NULL, NULL, NULL, NULL);
01613             avio_write(&b, "TTA1", 4);
01614             avio_wl16(&b, 1);
01615             avio_wl16(&b, track->audio.channels);
01616             avio_wl16(&b, track->audio.bitdepth);
01617             avio_wl32(&b, track->audio.out_samplerate);
01618             avio_wl32(&b, matroska->ctx->duration * track->audio.out_samplerate);
01619         } else if (codec_id == CODEC_ID_RV10 || codec_id == CODEC_ID_RV20 ||
01620                    codec_id == CODEC_ID_RV30 || codec_id == CODEC_ID_RV40) {
01621             extradata_offset = 26;
01622         } else if (codec_id == CODEC_ID_RA_144) {
01623             track->audio.out_samplerate = 8000;
01624             track->audio.channels = 1;
01625         } else if ((codec_id == CODEC_ID_RA_288 || codec_id == CODEC_ID_COOK ||
01626                     codec_id == CODEC_ID_ATRAC3 || codec_id == CODEC_ID_SIPR)
01627                     && track->codec_priv.data) {
01628             int flavor;
01629 
01630             ffio_init_context(&b, track->codec_priv.data,track->codec_priv.size,
01631                           0, NULL, NULL, NULL, NULL);
01632             avio_skip(&b, 22);
01633             flavor                       = avio_rb16(&b);
01634             track->audio.coded_framesize = avio_rb32(&b);
01635             avio_skip(&b, 12);
01636             track->audio.sub_packet_h    = avio_rb16(&b);
01637             track->audio.frame_size      = avio_rb16(&b);
01638             track->audio.sub_packet_size = avio_rb16(&b);
01639             track->audio.buf = av_malloc(track->audio.frame_size * track->audio.sub_packet_h);
01640             if (codec_id == CODEC_ID_RA_288) {
01641                 st->codec->block_align = track->audio.coded_framesize;
01642                 track->codec_priv.size = 0;
01643             } else {
01644                 if (codec_id == CODEC_ID_SIPR && flavor < 4) {
01645                     const int sipr_bit_rate[4] = { 6504, 8496, 5000, 16000 };
01646                     track->audio.sub_packet_size = ff_sipr_subpk_size[flavor];
01647                     st->codec->bit_rate = sipr_bit_rate[flavor];
01648                 }
01649                 st->codec->block_align = track->audio.sub_packet_size;
01650                 extradata_offset = 78;
01651             }
01652         }
01653         track->codec_priv.size -= extradata_offset;
01654 
01655         if (codec_id == CODEC_ID_NONE)
01656             av_log(matroska->ctx, AV_LOG_INFO,
01657                    "Unknown/unsupported CodecID %s.\n", track->codec_id);
01658 
01659         if (track->time_scale < 0.01)
01660             track->time_scale = 1.0;
01661         avpriv_set_pts_info(st, 64, matroska->time_scale*track->time_scale, 1000*1000*1000); /* 64 bit pts in ns */
01662 
01663         st->codec->codec_id = codec_id;
01664         st->start_time = 0;
01665         if (strcmp(track->language, "und"))
01666             av_dict_set(&st->metadata, "language", track->language, 0);
01667         av_dict_set(&st->metadata, "title", track->name, 0);
01668 
01669         if (track->flag_default)
01670             st->disposition |= AV_DISPOSITION_DEFAULT;
01671         if (track->flag_forced)
01672             st->disposition |= AV_DISPOSITION_FORCED;
01673 
01674         if (!st->codec->extradata) {
01675             if(extradata){
01676                 st->codec->extradata = extradata;
01677                 st->codec->extradata_size = extradata_size;
01678             } else if(track->codec_priv.data && track->codec_priv.size > 0){
01679                 st->codec->extradata = av_mallocz(track->codec_priv.size +
01680                                                   FF_INPUT_BUFFER_PADDING_SIZE);
01681                 if(st->codec->extradata == NULL)
01682                     return AVERROR(ENOMEM);
01683                 st->codec->extradata_size = track->codec_priv.size;
01684                 memcpy(st->codec->extradata,
01685                        track->codec_priv.data + extradata_offset,
01686                        track->codec_priv.size);
01687             }
01688         }
01689 
01690         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
01691             MatroskaTrackPlane *planes = track->operation.combine_planes.elem;
01692 
01693             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
01694             st->codec->codec_tag  = fourcc;
01695             st->codec->width  = track->video.pixel_width;
01696             st->codec->height = track->video.pixel_height;
01697             av_reduce(&st->sample_aspect_ratio.num,
01698                       &st->sample_aspect_ratio.den,
01699                       st->codec->height * track->video.display_width,
01700                       st->codec-> width * track->video.display_height,
01701                       255);
01702             st->need_parsing = AVSTREAM_PARSE_HEADERS;
01703             if (track->default_duration) {
01704                 av_reduce(&st->r_frame_rate.num, &st->r_frame_rate.den,
01705                           1000000000, track->default_duration, 30000);
01706                 st->avg_frame_rate = st->r_frame_rate;
01707             }
01708 
01709             /* export stereo mode flag as metadata tag */
01710             if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREO_MODE_COUNT)
01711                 av_dict_set(&st->metadata, "stereo_mode", matroska_video_stereo_mode[track->video.stereo_mode], 0);
01712 
01713             /* if we have virtual track, mark the real tracks */
01714             for (j=0; j < track->operation.combine_planes.nb_elem; j++) {
01715                 char buf[32];
01716                 if (planes[j].type >= MATROSKA_VIDEO_STEREO_PLANE_COUNT)
01717                     continue;
01718                 snprintf(buf, sizeof(buf), "%s_%d",
01719                          matroska_video_stereo_plane[planes[j].type], i);
01720                 for (k=0; k < matroska->tracks.nb_elem; k++)
01721                     if (planes[j].uid == tracks[k].uid) {
01722                         av_dict_set(&s->streams[k]->metadata,
01723                                     "stereo_mode", buf, 0);
01724                         break;
01725                     }
01726             }
01727         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
01728             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
01729             st->codec->sample_rate = track->audio.out_samplerate;
01730             st->codec->channels = track->audio.channels;
01731             if (st->codec->codec_id != CODEC_ID_AAC)
01732             st->need_parsing = AVSTREAM_PARSE_HEADERS;
01733         } else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
01734             st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
01735             if (st->codec->codec_id == CODEC_ID_SSA)
01736                 matroska->contains_ssa = 1;
01737         }
01738     }
01739 
01740     attachements = attachements_list->elem;
01741     for (j=0; j<attachements_list->nb_elem; j++) {
01742         if (!(attachements[j].filename && attachements[j].mime &&
01743               attachements[j].bin.data && attachements[j].bin.size > 0)) {
01744             av_log(matroska->ctx, AV_LOG_ERROR, "incomplete attachment\n");
01745         } else {
01746             AVStream *st = avformat_new_stream(s, NULL);
01747             if (st == NULL)
01748                 break;
01749             av_dict_set(&st->metadata, "filename",attachements[j].filename, 0);
01750             av_dict_set(&st->metadata, "mimetype", attachements[j].mime, 0);
01751             st->codec->codec_id = CODEC_ID_NONE;
01752             st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
01753             st->codec->extradata  = av_malloc(attachements[j].bin.size + FF_INPUT_BUFFER_PADDING_SIZE);
01754             if(st->codec->extradata == NULL)
01755                 break;
01756             st->codec->extradata_size = attachements[j].bin.size;
01757             memcpy(st->codec->extradata, attachements[j].bin.data, attachements[j].bin.size);
01758 
01759             for (i=0; ff_mkv_mime_tags[i].id != CODEC_ID_NONE; i++) {
01760                 if (!strncmp(ff_mkv_mime_tags[i].str, attachements[j].mime,
01761                              strlen(ff_mkv_mime_tags[i].str))) {
01762                     st->codec->codec_id = ff_mkv_mime_tags[i].id;
01763                     break;
01764                 }
01765             }
01766             attachements[j].stream = st;
01767         }
01768     }
01769 
01770     chapters = chapters_list->elem;
01771     for (i=0; i<chapters_list->nb_elem; i++)
01772         if (chapters[i].start != AV_NOPTS_VALUE && chapters[i].uid
01773             && (max_start==0 || chapters[i].start > max_start)) {
01774             chapters[i].chapter =
01775             avpriv_new_chapter(s, chapters[i].uid, (AVRational){1, 1000000000},
01776                            chapters[i].start, chapters[i].end,
01777                            chapters[i].title);
01778             av_dict_set(&chapters[i].chapter->metadata,
01779                              "title", chapters[i].title, 0);
01780             max_start = chapters[i].start;
01781         }
01782 
01783     matroska_add_index_entries(matroska);
01784 
01785     matroska_convert_tags(s);
01786 
01787     return 0;
01788 }
01789 
01790 /*
01791  * Put one packet in an application-supplied AVPacket struct.
01792  * Returns 0 on success or -1 on failure.
01793  */
01794 static int matroska_deliver_packet(MatroskaDemuxContext *matroska,
01795                                    AVPacket *pkt)
01796 {
01797     if (matroska->num_packets > 0) {
01798         memcpy(pkt, matroska->packets[0], sizeof(AVPacket));
01799         av_free(matroska->packets[0]);
01800         if (matroska->num_packets > 1) {
01801             void *newpackets;
01802             memmove(&matroska->packets[0], &matroska->packets[1],
01803                     (matroska->num_packets - 1) * sizeof(AVPacket *));
01804             newpackets = av_realloc(matroska->packets,
01805                             (matroska->num_packets - 1) * sizeof(AVPacket *));
01806             if (newpackets)
01807                 matroska->packets = newpackets;
01808         } else {
01809             av_freep(&matroska->packets);
01810             matroska->prev_pkt = NULL;
01811         }
01812         matroska->num_packets--;
01813         return 0;
01814     }
01815 
01816     return -1;
01817 }
01818 
01819 /*
01820  * Free all packets in our internal queue.
01821  */
01822 static void matroska_clear_queue(MatroskaDemuxContext *matroska)
01823 {
01824     if (matroska->packets) {
01825         int n;
01826         for (n = 0; n < matroska->num_packets; n++) {
01827             av_free_packet(matroska->packets[n]);
01828             av_free(matroska->packets[n]);
01829         }
01830         av_freep(&matroska->packets);
01831         matroska->num_packets = 0;
01832     }
01833 }
01834 
01835 static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
01836                                 int size, int64_t pos, uint64_t cluster_time,
01837                                 uint64_t duration, int is_keyframe,
01838                                 int64_t cluster_pos)
01839 {
01840     uint64_t timecode = AV_NOPTS_VALUE;
01841     MatroskaTrack *track;
01842     int res = 0;
01843     AVStream *st;
01844     AVPacket *pkt;
01845     int16_t block_time;
01846     uint32_t *lace_size = NULL;
01847     int n, flags, laces = 0;
01848     uint64_t num;
01849 
01850     if ((n = matroska_ebmlnum_uint(matroska, data, size, &num)) < 0) {
01851         av_log(matroska->ctx, AV_LOG_ERROR, "EBML block data error\n");
01852         return n;
01853     }
01854     data += n;
01855     size -= n;
01856 
01857     track = matroska_find_track_by_num(matroska, num);
01858     if (!track || !track->stream) {
01859         av_log(matroska->ctx, AV_LOG_INFO,
01860                "Invalid stream %"PRIu64" or size %u\n", num, size);
01861         return AVERROR_INVALIDDATA;
01862     } else if (size <= 3)
01863         return 0;
01864     st = track->stream;
01865     if (st->discard >= AVDISCARD_ALL)
01866         return res;
01867     av_assert1(duration != AV_NOPTS_VALUE);
01868     if (!duration)
01869         duration = track->default_duration / matroska->time_scale;
01870 
01871     block_time = AV_RB16(data);
01872     data += 2;
01873     flags = *data++;
01874     size -= 3;
01875     if (is_keyframe == -1)
01876         is_keyframe = flags & 0x80 ? AV_PKT_FLAG_KEY : 0;
01877 
01878     if (cluster_time != (uint64_t)-1
01879         && (block_time >= 0 || cluster_time >= -block_time)) {
01880         timecode = cluster_time + block_time;
01881         if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE
01882             && timecode < track->end_timecode)
01883             is_keyframe = 0;  /* overlapping subtitles are not key frame */
01884         if (is_keyframe)
01885             av_add_index_entry(st, cluster_pos, timecode, 0,0,AVINDEX_KEYFRAME);
01886         track->end_timecode = FFMAX(track->end_timecode, timecode+duration);
01887     }
01888 
01889     if (matroska->skip_to_keyframe && track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
01890         if (timecode < matroska->skip_to_timecode)
01891             return res;
01892         if (!st->skip_to_keyframe) {
01893             av_log(matroska->ctx, AV_LOG_ERROR, "File is broken, keyframes not correctly marked!\n");
01894             matroska->skip_to_keyframe = 0;
01895         }
01896         if (is_keyframe)
01897             matroska->skip_to_keyframe = 0;
01898     }
01899 
01900     switch ((flags & 0x06) >> 1) {
01901         case 0x0: /* no lacing */
01902             laces = 1;
01903             lace_size = av_mallocz(sizeof(int));
01904             lace_size[0] = size;
01905             break;
01906 
01907         case 0x1: /* Xiph lacing */
01908         case 0x2: /* fixed-size lacing */
01909         case 0x3: /* EBML lacing */
01910             assert(size>0); // size <=3 is checked before size-=3 above
01911             laces = (*data) + 1;
01912             data += 1;
01913             size -= 1;
01914             lace_size = av_mallocz(laces * sizeof(int));
01915 
01916             switch ((flags & 0x06) >> 1) {
01917                 case 0x1: /* Xiph lacing */ {
01918                     uint8_t temp;
01919                     uint32_t total = 0;
01920                     for (n = 0; res == 0 && n < laces - 1; n++) {
01921                         while (1) {
01922                             if (size == 0) {
01923                                 res = -1;
01924                                 break;
01925                             }
01926                             temp = *data;
01927                             lace_size[n] += temp;
01928                             data += 1;
01929                             size -= 1;
01930                             if (temp != 0xff)
01931                                 break;
01932                         }
01933                         total += lace_size[n];
01934                     }
01935                     lace_size[n] = size - total;
01936                     break;
01937                 }
01938 
01939                 case 0x2: /* fixed-size lacing */
01940                     for (n = 0; n < laces; n++)
01941                         lace_size[n] = size / laces;
01942                     break;
01943 
01944                 case 0x3: /* EBML lacing */ {
01945                     uint32_t total;
01946                     n = matroska_ebmlnum_uint(matroska, data, size, &num);
01947                     if (n < 0) {
01948                         av_log(matroska->ctx, AV_LOG_INFO,
01949                                "EBML block data error\n");
01950                         break;
01951                     }
01952                     data += n;
01953                     size -= n;
01954                     total = lace_size[0] = num;
01955                     for (n = 1; res == 0 && n < laces - 1; n++) {
01956                         int64_t snum;
01957                         int r;
01958                         r = matroska_ebmlnum_sint(matroska, data, size, &snum);
01959                         if (r < 0) {
01960                             av_log(matroska->ctx, AV_LOG_INFO,
01961                                    "EBML block data error\n");
01962                             break;
01963                         }
01964                         data += r;
01965                         size -= r;
01966                         lace_size[n] = lace_size[n - 1] + snum;
01967                         total += lace_size[n];
01968                     }
01969                     lace_size[laces - 1] = size - total;
01970                     break;
01971                 }
01972             }
01973             break;
01974     }
01975 
01976     if (res == 0) {
01977         for (n = 0; n < laces; n++) {
01978             if ((st->codec->codec_id == CODEC_ID_RA_288 ||
01979                  st->codec->codec_id == CODEC_ID_COOK ||
01980                  st->codec->codec_id == CODEC_ID_SIPR ||
01981                  st->codec->codec_id == CODEC_ID_ATRAC3) &&
01982                  st->codec->block_align && track->audio.sub_packet_size) {
01983                 int a = st->codec->block_align;
01984                 int sps = track->audio.sub_packet_size;
01985                 int cfs = track->audio.coded_framesize;
01986                 int h = track->audio.sub_packet_h;
01987                 int y = track->audio.sub_packet_cnt;
01988                 int w = track->audio.frame_size;
01989                 int x;
01990 
01991                 if (!track->audio.pkt_cnt) {
01992                     if (track->audio.sub_packet_cnt == 0)
01993                         track->audio.buf_timecode = timecode;
01994                     if (st->codec->codec_id == CODEC_ID_RA_288) {
01995                         if (size < cfs * h / 2) {
01996                             av_log(matroska->ctx, AV_LOG_ERROR,
01997                                    "Corrupt int4 RM-style audio packet size\n");
01998                             res = AVERROR_INVALIDDATA;
01999                             goto end;
02000                         }
02001                         for (x=0; x<h/2; x++)
02002                             memcpy(track->audio.buf+x*2*w+y*cfs,
02003                                    data+x*cfs, cfs);
02004                     } else if (st->codec->codec_id == CODEC_ID_SIPR) {
02005                         if (size < w) {
02006                             av_log(matroska->ctx, AV_LOG_ERROR,
02007                                    "Corrupt sipr RM-style audio packet size\n");
02008                             res = AVERROR_INVALIDDATA;
02009                             goto end;
02010                         }
02011                         memcpy(track->audio.buf + y*w, data, w);
02012                     } else {
02013                         if (size < sps * w / sps) {
02014                             av_log(matroska->ctx, AV_LOG_ERROR,
02015                                    "Corrupt generic RM-style audio packet size\n");
02016                             res = AVERROR_INVALIDDATA;
02017                             goto end;
02018                         }
02019                         for (x=0; x<w/sps; x++)
02020                             memcpy(track->audio.buf+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), data+x*sps, sps);
02021                     }
02022 
02023                     if (++track->audio.sub_packet_cnt >= h) {
02024                         if (st->codec->codec_id == CODEC_ID_SIPR)
02025                             ff_rm_reorder_sipr_data(track->audio.buf, h, w);
02026                         track->audio.sub_packet_cnt = 0;
02027                         track->audio.pkt_cnt = h*w / a;
02028                     }
02029                 }
02030                 while (track->audio.pkt_cnt) {
02031                     pkt = av_mallocz(sizeof(AVPacket));
02032                     av_new_packet(pkt, a);
02033                     memcpy(pkt->data, track->audio.buf
02034                            + a * (h*w / a - track->audio.pkt_cnt--), a);
02035                     pkt->pts = track->audio.buf_timecode;
02036                     track->audio.buf_timecode = AV_NOPTS_VALUE;
02037                     pkt->pos = pos;
02038                     pkt->stream_index = st->index;
02039                     dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
02040                 }
02041             } else {
02042                 MatroskaTrackEncoding *encodings = track->encodings.elem;
02043                 int offset = 0, pkt_size = lace_size[n];
02044                 uint8_t *pkt_data = data;
02045 
02046                 if (pkt_size > size) {
02047                     av_log(matroska->ctx, AV_LOG_ERROR, "Invalid packet size\n");
02048                     break;
02049                 }
02050 
02051                 if (encodings && encodings->scope & 1) {
02052                     offset = matroska_decode_buffer(&pkt_data,&pkt_size, track);
02053                     if (offset < 0)
02054                         continue;
02055                 }
02056 
02057                 pkt = av_mallocz(sizeof(AVPacket));
02058                 /* XXX: prevent data copy... */
02059                 if (av_new_packet(pkt, pkt_size+offset) < 0) {
02060                     av_free(pkt);
02061                     res = AVERROR(ENOMEM);
02062                     break;
02063                 }
02064                 if (offset)
02065                     memcpy (pkt->data, encodings->compression.settings.data, offset);
02066                 memcpy (pkt->data+offset, pkt_data, pkt_size);
02067 
02068                 if (pkt_data != data)
02069                     av_free(pkt_data);
02070 
02071                 if (n == 0)
02072                     pkt->flags = is_keyframe;
02073                 pkt->stream_index = st->index;
02074 
02075                 if (track->ms_compat)
02076                     pkt->dts = timecode;
02077                 else
02078                     pkt->pts = timecode;
02079                 pkt->pos = pos;
02080                 if (st->codec->codec_id == CODEC_ID_TEXT)
02081                     pkt->convergence_duration = duration;
02082                 else if (track->type != MATROSKA_TRACK_TYPE_SUBTITLE)
02083                     pkt->duration = duration;
02084 
02085                 if (st->codec->codec_id == CODEC_ID_SSA)
02086                     matroska_fix_ass_packet(matroska, pkt, duration);
02087 
02088                 if (matroska->prev_pkt &&
02089                     timecode != AV_NOPTS_VALUE &&
02090                     matroska->prev_pkt->pts == timecode &&
02091                     matroska->prev_pkt->stream_index == st->index &&
02092                     st->codec->codec_id == CODEC_ID_SSA)
02093                     matroska_merge_packets(matroska->prev_pkt, pkt);
02094                 else {
02095                     dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
02096                     matroska->prev_pkt = pkt;
02097                 }
02098             }
02099 
02100             if (timecode != AV_NOPTS_VALUE)
02101                 timecode = duration ? timecode + duration : AV_NOPTS_VALUE;
02102             data += lace_size[n];
02103             size -= lace_size[n];
02104         }
02105     }
02106 
02107 end:
02108     av_free(lace_size);
02109     return res;
02110 }
02111 
02112 static int matroska_parse_cluster_incremental(MatroskaDemuxContext *matroska)
02113 {
02114     EbmlList *blocks_list;
02115     MatroskaBlock *blocks;
02116     int i, res;
02117     res = ebml_parse(matroska,
02118                      matroska_cluster_incremental_parsing,
02119                      &matroska->current_cluster);
02120     if (res == 1) {
02121         /* New Cluster */
02122         if (matroska->current_cluster_pos)
02123             ebml_level_end(matroska);
02124         ebml_free(matroska_cluster, &matroska->current_cluster);
02125         memset(&matroska->current_cluster, 0, sizeof(MatroskaCluster));
02126         matroska->current_cluster_num_blocks = 0;
02127         matroska->current_cluster_pos = avio_tell(matroska->ctx->pb);
02128         matroska->prev_pkt = NULL;
02129         /* sizeof the ID which was already read */
02130         if (matroska->current_id)
02131             matroska->current_cluster_pos -= 4;
02132         res = ebml_parse(matroska,
02133                          matroska_clusters_incremental,
02134                          &matroska->current_cluster);
02135         /* Try parsing the block again. */
02136         if (res == 1)
02137             res = ebml_parse(matroska,
02138                              matroska_cluster_incremental_parsing,
02139                              &matroska->current_cluster);
02140     }
02141 
02142     if (!res &&
02143         matroska->current_cluster_num_blocks <
02144             matroska->current_cluster.blocks.nb_elem) {
02145         blocks_list = &matroska->current_cluster.blocks;
02146         blocks = blocks_list->elem;
02147 
02148         matroska->current_cluster_num_blocks = blocks_list->nb_elem;
02149         i = blocks_list->nb_elem - 1;
02150         if (blocks[i].bin.size > 0 && blocks[i].bin.data) {
02151             int is_keyframe = blocks[i].non_simple ? !blocks[i].reference : -1;
02152             if (!blocks[i].non_simple)
02153                 blocks[i].duration = 0;
02154             res = matroska_parse_block(matroska,
02155                                        blocks[i].bin.data, blocks[i].bin.size,
02156                                        blocks[i].bin.pos,
02157                                        matroska->current_cluster.timecode,
02158                                        blocks[i].duration, is_keyframe,
02159                                        matroska->current_cluster_pos);
02160         }
02161     }
02162 
02163     if (res < 0)  matroska->done = 1;
02164     return res;
02165 }
02166 
02167 static int matroska_parse_cluster(MatroskaDemuxContext *matroska)
02168 {
02169     MatroskaCluster cluster = { 0 };
02170     EbmlList *blocks_list;
02171     MatroskaBlock *blocks;
02172     int i, res;
02173     int64_t pos;
02174     if (!matroska->contains_ssa)
02175         return matroska_parse_cluster_incremental(matroska);
02176     pos = avio_tell(matroska->ctx->pb);
02177     matroska->prev_pkt = NULL;
02178     if (matroska->current_id)
02179         pos -= 4;  /* sizeof the ID which was already read */
02180     res = ebml_parse(matroska, matroska_clusters, &cluster);
02181     blocks_list = &cluster.blocks;
02182     blocks = blocks_list->elem;
02183     for (i=0; i<blocks_list->nb_elem; i++)
02184         if (blocks[i].bin.size > 0 && blocks[i].bin.data) {
02185             int is_keyframe = blocks[i].non_simple ? !blocks[i].reference : -1;
02186             res=matroska_parse_block(matroska,
02187                                      blocks[i].bin.data, blocks[i].bin.size,
02188                                      blocks[i].bin.pos,  cluster.timecode,
02189                                      blocks[i].duration, is_keyframe,
02190                                      pos);
02191         }
02192     ebml_free(matroska_cluster, &cluster);
02193     return res;
02194 }
02195 
02196 static int matroska_read_packet(AVFormatContext *s, AVPacket *pkt)
02197 {
02198     MatroskaDemuxContext *matroska = s->priv_data;
02199 
02200     while (matroska_deliver_packet(matroska, pkt)) {
02201         int64_t pos = avio_tell(matroska->ctx->pb);
02202         if (matroska->done)
02203             return AVERROR_EOF;
02204         if (matroska_parse_cluster(matroska) < 0)
02205             matroska_resync(matroska, pos);
02206     }
02207 
02208     return 0;
02209 }
02210 
02211 static int matroska_read_seek(AVFormatContext *s, int stream_index,
02212                               int64_t timestamp, int flags)
02213 {
02214     MatroskaDemuxContext *matroska = s->priv_data;
02215     MatroskaTrack *tracks = matroska->tracks.elem;
02216     AVStream *st = s->streams[stream_index];
02217     int i, index, index_sub, index_min;
02218 
02219     /* Parse the CUES now since we need the index data to seek. */
02220     if (matroska->cues_parsing_deferred > 0) {
02221         matroska->cues_parsing_deferred = 0;
02222         matroska_parse_cues(matroska);
02223     }
02224 
02225     if (!st->nb_index_entries)
02226         goto err;
02227     timestamp = FFMAX(timestamp, st->index_entries[0].timestamp);
02228 
02229     if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
02230         avio_seek(s->pb, st->index_entries[st->nb_index_entries-1].pos, SEEK_SET);
02231         matroska->current_id = 0;
02232         while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
02233             matroska->prev_pkt = NULL;
02234             matroska_clear_queue(matroska);
02235             if (matroska_parse_cluster(matroska) < 0)
02236                 break;
02237         }
02238     }
02239 
02240     matroska_clear_queue(matroska);
02241     if (index < 0 || (matroska->cues_parsing_deferred < 0 && index == st->nb_index_entries - 1))
02242         goto err;
02243 
02244     index_min = index;
02245     for (i=0; i < matroska->tracks.nb_elem; i++) {
02246         tracks[i].audio.pkt_cnt = 0;
02247         tracks[i].audio.sub_packet_cnt = 0;
02248         tracks[i].audio.buf_timecode = AV_NOPTS_VALUE;
02249         tracks[i].end_timecode = 0;
02250         if (tracks[i].type == MATROSKA_TRACK_TYPE_SUBTITLE
02251             && !tracks[i].stream->discard != AVDISCARD_ALL) {
02252             index_sub = av_index_search_timestamp(tracks[i].stream, st->index_entries[index].timestamp, AVSEEK_FLAG_BACKWARD);
02253             if (index_sub >= 0
02254                 && st->index_entries[index_sub].pos < st->index_entries[index_min].pos
02255                 && st->index_entries[index].timestamp - st->index_entries[index_sub].timestamp < 30000000000/matroska->time_scale)
02256                 index_min = index_sub;
02257         }
02258     }
02259 
02260     avio_seek(s->pb, st->index_entries[index_min].pos, SEEK_SET);
02261     matroska->current_id = 0;
02262     st->skip_to_keyframe =
02263     matroska->skip_to_keyframe = !(flags & AVSEEK_FLAG_ANY);
02264     matroska->skip_to_timecode = st->index_entries[index].timestamp;
02265     matroska->done = 0;
02266     matroska->num_levels = 0;
02267     ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
02268     return 0;
02269 err:
02270     // slightly hackish but allows proper fallback to
02271     // the generic seeking code.
02272     matroska_clear_queue(matroska);
02273     matroska->current_id = 0;
02274     st->skip_to_keyframe =
02275     matroska->skip_to_keyframe = 0;
02276     matroska->done = 0;
02277     matroska->num_levels = 0;
02278     return -1;
02279 }
02280 
02281 static int matroska_read_close(AVFormatContext *s)
02282 {
02283     MatroskaDemuxContext *matroska = s->priv_data;
02284     MatroskaTrack *tracks = matroska->tracks.elem;
02285     int n;
02286 
02287     matroska_clear_queue(matroska);
02288 
02289     for (n=0; n < matroska->tracks.nb_elem; n++)
02290         if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)
02291             av_free(tracks[n].audio.buf);
02292     ebml_free(matroska_cluster, &matroska->current_cluster);
02293     ebml_free(matroska_segment, matroska);
02294 
02295     return 0;
02296 }
02297 
02298 AVInputFormat ff_matroska_demuxer = {
02299     .name           = "matroska,webm",
02300     .long_name      = NULL_IF_CONFIG_SMALL("Matroska/WebM file format"),
02301     .priv_data_size = sizeof(MatroskaDemuxContext),
02302     .read_probe     = matroska_probe,
02303     .read_header    = matroska_read_header,
02304     .read_packet    = matroska_read_packet,
02305     .read_close     = matroska_read_close,
02306     .read_seek      = matroska_read_seek,
02307 };