1/*
2 * Matroska file demuxer
3 * Copyright (c) 2003-2008 The FFmpeg Project
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file libavformat/matroskadec.c
24 * Matroska file demuxer
25 * by Ronald Bultje <rbultje@ronald.bitfreak.net>
26 * with a little help from Moritz Bunkus <moritz@bunkus.org>
27 * totally reworked by Aurelien Jacobs <aurel@gnuage.org>
28 * Specs available on the Matroska project page: http://www.matroska.org/.
29 */
30
31#include <stdio.h>
32#include "avformat.h"
33/* For codec_get_id(). */
34#include "riff.h"
35#include "isom.h"
36#include "matroska.h"
37#include "libavcodec/mpeg4audio.h"
38#include "libavutil/intfloat_readwrite.h"
39#include "libavutil/intreadwrite.h"
40#include "libavutil/avstring.h"
41#include "libavutil/lzo.h"
42#if CONFIG_ZLIB
43#include <zlib.h>
44#endif
45#if CONFIG_BZLIB
46#include <bzlib.h>
47#endif
48
49typedef enum {
50    EBML_NONE,
51    EBML_UINT,
52    EBML_FLOAT,
53    EBML_STR,
54    EBML_UTF8,
55    EBML_BIN,
56    EBML_NEST,
57    EBML_PASS,
58    EBML_STOP,
59} EbmlType;
60
61typedef const struct EbmlSyntax {
62    uint32_t id;
63    EbmlType type;
64    int list_elem_size;
65    int data_offset;
66    union {
67        uint64_t    u;
68        double      f;
69        const char *s;
70        const struct EbmlSyntax *n;
71    } def;
72} EbmlSyntax;
73
74typedef struct {
75    int nb_elem;
76    void *elem;
77} EbmlList;
78
79typedef struct {
80    int      size;
81    uint8_t *data;
82    int64_t  pos;
83} EbmlBin;
84
85typedef struct {
86    uint64_t version;
87    uint64_t max_size;
88    uint64_t id_length;
89    char    *doctype;
90    uint64_t doctype_version;
91} Ebml;
92
93typedef struct {
94    uint64_t algo;
95    EbmlBin  settings;
96} MatroskaTrackCompression;
97
98typedef struct {
99    uint64_t scope;
100    uint64_t type;
101    MatroskaTrackCompression compression;
102} MatroskaTrackEncoding;
103
104typedef struct {
105    double   frame_rate;
106    uint64_t display_width;
107    uint64_t display_height;
108    uint64_t pixel_width;
109    uint64_t pixel_height;
110    uint64_t fourcc;
111} MatroskaTrackVideo;
112
113typedef struct {
114    double   samplerate;
115    double   out_samplerate;
116    uint64_t bitdepth;
117    uint64_t channels;
118
119    /* real audio header (extracted from extradata) */
120    int      coded_framesize;
121    int      sub_packet_h;
122    int      frame_size;
123    int      sub_packet_size;
124    int      sub_packet_cnt;
125    int      pkt_cnt;
126    uint8_t *buf;
127} MatroskaTrackAudio;
128
129typedef struct {
130    uint64_t num;
131    uint64_t uid;
132    uint64_t type;
133    char    *name;
134    char    *codec_id;
135    EbmlBin  codec_priv;
136    char    *language;
137    double time_scale;
138    uint64_t default_duration;
139    uint64_t flag_default;
140    MatroskaTrackVideo video;
141    MatroskaTrackAudio audio;
142    EbmlList encodings;
143
144    AVStream *stream;
145    int64_t end_timecode;
146} MatroskaTrack;
147
148typedef struct {
149    uint64_t uid;
150    char *filename;
151    char *mime;
152    EbmlBin bin;
153
154    AVStream *stream;
155} MatroskaAttachement;
156
157typedef struct {
158    uint64_t start;
159    uint64_t end;
160    uint64_t uid;
161    char    *title;
162
163    AVChapter *chapter;
164} MatroskaChapter;
165
166typedef struct {
167    uint64_t track;
168    uint64_t pos;
169} MatroskaIndexPos;
170
171typedef struct {
172    uint64_t time;
173    EbmlList pos;
174} MatroskaIndex;
175
176typedef struct {
177    char *name;
178    char *string;
179    char *lang;
180    uint64_t def;
181    EbmlList sub;
182} MatroskaTag;
183
184typedef struct {
185    char    *type;
186    uint64_t typevalue;
187    uint64_t trackuid;
188    uint64_t chapteruid;
189    uint64_t attachuid;
190} MatroskaTagTarget;
191
192typedef struct {
193    MatroskaTagTarget target;
194    EbmlList tag;
195} MatroskaTags;
196
197typedef struct {
198    uint64_t id;
199    uint64_t pos;
200} MatroskaSeekhead;
201
202typedef struct {
203    uint64_t start;
204    uint64_t length;
205} MatroskaLevel;
206
207typedef struct {
208    AVFormatContext *ctx;
209
210    /* EBML stuff */
211    int num_levels;
212    MatroskaLevel levels[EBML_MAX_DEPTH];
213    int level_up;
214
215    uint64_t time_scale;
216    double   duration;
217    char    *title;
218    EbmlList tracks;
219    EbmlList attachments;
220    EbmlList chapters;
221    EbmlList index;
222    EbmlList tags;
223    EbmlList seekhead;
224
225    /* byte position of the segment inside the stream */
226    int64_t segment_start;
227
228    /* the packet queue */
229    AVPacket **packets;
230    int num_packets;
231    AVPacket *prev_pkt;
232
233    int done;
234    int has_cluster_id;
235
236    /* What to skip before effectively reading a packet. */
237    int skip_to_keyframe;
238    uint64_t skip_to_timecode;
239} MatroskaDemuxContext;
240
241typedef struct {
242    uint64_t duration;
243    int64_t  reference;
244    EbmlBin  bin;
245} MatroskaBlock;
246
247typedef struct {
248    uint64_t timecode;
249    EbmlList blocks;
250} MatroskaCluster;
251
252static EbmlSyntax ebml_header[] = {
253    { EBML_ID_EBMLREADVERSION,        EBML_UINT, 0, offsetof(Ebml,version), {.u=EBML_VERSION} },
254    { EBML_ID_EBMLMAXSIZELENGTH,      EBML_UINT, 0, offsetof(Ebml,max_size), {.u=8} },
255    { EBML_ID_EBMLMAXIDLENGTH,        EBML_UINT, 0, offsetof(Ebml,id_length), {.u=4} },
256    { EBML_ID_DOCTYPE,                EBML_STR,  0, offsetof(Ebml,doctype), {.s="(none)"} },
257    { EBML_ID_DOCTYPEREADVERSION,     EBML_UINT, 0, offsetof(Ebml,doctype_version), {.u=1} },
258    { EBML_ID_EBMLVERSION,            EBML_NONE },
259    { EBML_ID_DOCTYPEVERSION,         EBML_NONE },
260    { 0 }
261};
262
263static EbmlSyntax ebml_syntax[] = {
264    { EBML_ID_HEADER,                 EBML_NEST, 0, 0, {.n=ebml_header} },
265    { 0 }
266};
267
268static EbmlSyntax matroska_info[] = {
269    { MATROSKA_ID_TIMECODESCALE,      EBML_UINT,  0, offsetof(MatroskaDemuxContext,time_scale), {.u=1000000} },
270    { MATROSKA_ID_DURATION,           EBML_FLOAT, 0, offsetof(MatroskaDemuxContext,duration) },
271    { MATROSKA_ID_TITLE,              EBML_UTF8,  0, offsetof(MatroskaDemuxContext,title) },
272    { MATROSKA_ID_WRITINGAPP,         EBML_NONE },
273    { MATROSKA_ID_MUXINGAPP,          EBML_NONE },
274    { MATROSKA_ID_DATEUTC,            EBML_NONE },
275    { MATROSKA_ID_SEGMENTUID,         EBML_NONE },
276    { 0 }
277};
278
279static EbmlSyntax matroska_track_video[] = {
280    { MATROSKA_ID_VIDEOFRAMERATE,     EBML_FLOAT,0, offsetof(MatroskaTrackVideo,frame_rate) },
281    { MATROSKA_ID_VIDEODISPLAYWIDTH,  EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_width) },
282    { MATROSKA_ID_VIDEODISPLAYHEIGHT, EBML_UINT, 0, offsetof(MatroskaTrackVideo,display_height) },
283    { MATROSKA_ID_VIDEOPIXELWIDTH,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_width) },
284    { MATROSKA_ID_VIDEOPIXELHEIGHT,   EBML_UINT, 0, offsetof(MatroskaTrackVideo,pixel_height) },
285    { MATROSKA_ID_VIDEOCOLORSPACE,    EBML_UINT, 0, offsetof(MatroskaTrackVideo,fourcc) },
286    { MATROSKA_ID_VIDEOPIXELCROPB,    EBML_NONE },
287    { MATROSKA_ID_VIDEOPIXELCROPT,    EBML_NONE },
288    { MATROSKA_ID_VIDEOPIXELCROPL,    EBML_NONE },
289    { MATROSKA_ID_VIDEOPIXELCROPR,    EBML_NONE },
290    { MATROSKA_ID_VIDEODISPLAYUNIT,   EBML_NONE },
291    { MATROSKA_ID_VIDEOFLAGINTERLACED,EBML_NONE },
292    { MATROSKA_ID_VIDEOSTEREOMODE,    EBML_NONE },
293    { MATROSKA_ID_VIDEOASPECTRATIO,   EBML_NONE },
294    { 0 }
295};
296
297static EbmlSyntax matroska_track_audio[] = {
298    { MATROSKA_ID_AUDIOSAMPLINGFREQ,  EBML_FLOAT,0, offsetof(MatroskaTrackAudio,samplerate), {.f=8000.0} },
299    { MATROSKA_ID_AUDIOOUTSAMPLINGFREQ,EBML_FLOAT,0,offsetof(MatroskaTrackAudio,out_samplerate) },
300    { MATROSKA_ID_AUDIOBITDEPTH,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,bitdepth) },
301    { MATROSKA_ID_AUDIOCHANNELS,      EBML_UINT, 0, offsetof(MatroskaTrackAudio,channels), {.u=1} },
302    { 0 }
303};
304
305static EbmlSyntax matroska_track_encoding_compression[] = {
306    { MATROSKA_ID_ENCODINGCOMPALGO,   EBML_UINT, 0, offsetof(MatroskaTrackCompression,algo), {.u=0} },
307    { MATROSKA_ID_ENCODINGCOMPSETTINGS,EBML_BIN, 0, offsetof(MatroskaTrackCompression,settings) },
308    { 0 }
309};
310
311static EbmlSyntax matroska_track_encoding[] = {
312    { MATROSKA_ID_ENCODINGSCOPE,      EBML_UINT, 0, offsetof(MatroskaTrackEncoding,scope), {.u=1} },
313    { MATROSKA_ID_ENCODINGTYPE,       EBML_UINT, 0, offsetof(MatroskaTrackEncoding,type), {.u=0} },
314    { MATROSKA_ID_ENCODINGCOMPRESSION,EBML_NEST, 0, offsetof(MatroskaTrackEncoding,compression), {.n=matroska_track_encoding_compression} },
315    { MATROSKA_ID_ENCODINGORDER,      EBML_NONE },
316    { 0 }
317};
318
319static EbmlSyntax matroska_track_encodings[] = {
320    { MATROSKA_ID_TRACKCONTENTENCODING, EBML_NEST, sizeof(MatroskaTrackEncoding), offsetof(MatroskaTrack,encodings), {.n=matroska_track_encoding} },
321    { 0 }
322};
323
324static EbmlSyntax matroska_track[] = {
325    { MATROSKA_ID_TRACKNUMBER,          EBML_UINT, 0, offsetof(MatroskaTrack,num) },
326    { MATROSKA_ID_TRACKNAME,            EBML_UTF8, 0, offsetof(MatroskaTrack,name) },
327    { MATROSKA_ID_TRACKUID,             EBML_UINT, 0, offsetof(MatroskaTrack,uid) },
328    { MATROSKA_ID_TRACKTYPE,            EBML_UINT, 0, offsetof(MatroskaTrack,type) },
329    { MATROSKA_ID_CODECID,              EBML_STR,  0, offsetof(MatroskaTrack,codec_id) },
330    { MATROSKA_ID_CODECPRIVATE,         EBML_BIN,  0, offsetof(MatroskaTrack,codec_priv) },
331    { MATROSKA_ID_TRACKLANGUAGE,        EBML_UTF8, 0, offsetof(MatroskaTrack,language), {.s="eng"} },
332    { MATROSKA_ID_TRACKDEFAULTDURATION, EBML_UINT, 0, offsetof(MatroskaTrack,default_duration) },
333    { MATROSKA_ID_TRACKTIMECODESCALE,   EBML_FLOAT,0, offsetof(MatroskaTrack,time_scale), {.f=1.0} },
334    { MATROSKA_ID_TRACKFLAGDEFAULT,     EBML_UINT, 0, offsetof(MatroskaTrack,flag_default), {.u=1} },
335    { MATROSKA_ID_TRACKVIDEO,           EBML_NEST, 0, offsetof(MatroskaTrack,video), {.n=matroska_track_video} },
336    { MATROSKA_ID_TRACKAUDIO,           EBML_NEST, 0, offsetof(MatroskaTrack,audio), {.n=matroska_track_audio} },
337    { MATROSKA_ID_TRACKCONTENTENCODINGS,EBML_NEST, 0, 0, {.n=matroska_track_encodings} },
338    { MATROSKA_ID_TRACKFLAGENABLED,     EBML_NONE },
339    { MATROSKA_ID_TRACKFLAGFORCED,      EBML_NONE },
340    { MATROSKA_ID_TRACKFLAGLACING,      EBML_NONE },
341    { MATROSKA_ID_CODECNAME,            EBML_NONE },
342    { MATROSKA_ID_CODECDECODEALL,       EBML_NONE },
343    { MATROSKA_ID_CODECINFOURL,         EBML_NONE },
344    { MATROSKA_ID_CODECDOWNLOADURL,     EBML_NONE },
345    { MATROSKA_ID_TRACKMINCACHE,        EBML_NONE },
346    { MATROSKA_ID_TRACKMAXCACHE,        EBML_NONE },
347    { MATROSKA_ID_TRACKMAXBLKADDID,     EBML_NONE },
348    { 0 }
349};
350
351static EbmlSyntax matroska_tracks[] = {
352    { MATROSKA_ID_TRACKENTRY,         EBML_NEST, sizeof(MatroskaTrack), offsetof(MatroskaDemuxContext,tracks), {.n=matroska_track} },
353    { 0 }
354};
355
356static EbmlSyntax matroska_attachment[] = {
357    { MATROSKA_ID_FILEUID,            EBML_UINT, 0, offsetof(MatroskaAttachement,uid) },
358    { MATROSKA_ID_FILENAME,           EBML_UTF8, 0, offsetof(MatroskaAttachement,filename) },
359    { MATROSKA_ID_FILEMIMETYPE,       EBML_STR,  0, offsetof(MatroskaAttachement,mime) },
360    { MATROSKA_ID_FILEDATA,           EBML_BIN,  0, offsetof(MatroskaAttachement,bin) },
361    { MATROSKA_ID_FILEDESC,           EBML_NONE },
362    { 0 }
363};
364
365static EbmlSyntax matroska_attachments[] = {
366    { MATROSKA_ID_ATTACHEDFILE,       EBML_NEST, sizeof(MatroskaAttachement), offsetof(MatroskaDemuxContext,attachments), {.n=matroska_attachment} },
367    { 0 }
368};
369
370static EbmlSyntax matroska_chapter_display[] = {
371    { MATROSKA_ID_CHAPSTRING,         EBML_UTF8, 0, offsetof(MatroskaChapter,title) },
372    { MATROSKA_ID_CHAPLANG,           EBML_NONE },
373    { 0 }
374};
375
376static EbmlSyntax matroska_chapter_entry[] = {
377    { MATROSKA_ID_CHAPTERTIMESTART,   EBML_UINT, 0, offsetof(MatroskaChapter,start), {.u=AV_NOPTS_VALUE} },
378    { MATROSKA_ID_CHAPTERTIMEEND,     EBML_UINT, 0, offsetof(MatroskaChapter,end), {.u=AV_NOPTS_VALUE} },
379    { MATROSKA_ID_CHAPTERUID,         EBML_UINT, 0, offsetof(MatroskaChapter,uid) },
380    { MATROSKA_ID_CHAPTERDISPLAY,     EBML_NEST, 0, 0, {.n=matroska_chapter_display} },
381    { MATROSKA_ID_CHAPTERFLAGHIDDEN,  EBML_NONE },
382    { MATROSKA_ID_CHAPTERFLAGENABLED, EBML_NONE },
383    { MATROSKA_ID_CHAPTERPHYSEQUIV,   EBML_NONE },
384    { MATROSKA_ID_CHAPTERATOM,        EBML_NONE },
385    { 0 }
386};
387
388static EbmlSyntax matroska_chapter[] = {
389    { MATROSKA_ID_CHAPTERATOM,        EBML_NEST, sizeof(MatroskaChapter), offsetof(MatroskaDemuxContext,chapters), {.n=matroska_chapter_entry} },
390    { MATROSKA_ID_EDITIONUID,         EBML_NONE },
391    { MATROSKA_ID_EDITIONFLAGHIDDEN,  EBML_NONE },
392    { MATROSKA_ID_EDITIONFLAGDEFAULT, EBML_NONE },
393    { MATROSKA_ID_EDITIONFLAGORDERED, EBML_NONE },
394    { 0 }
395};
396
397static EbmlSyntax matroska_chapters[] = {
398    { MATROSKA_ID_EDITIONENTRY,       EBML_NEST, 0, 0, {.n=matroska_chapter} },
399    { 0 }
400};
401
402static EbmlSyntax matroska_index_pos[] = {
403    { MATROSKA_ID_CUETRACK,           EBML_UINT, 0, offsetof(MatroskaIndexPos,track) },
404    { MATROSKA_ID_CUECLUSTERPOSITION, EBML_UINT, 0, offsetof(MatroskaIndexPos,pos)   },
405    { MATROSKA_ID_CUEBLOCKNUMBER,     EBML_NONE },
406    { 0 }
407};
408
409static EbmlSyntax matroska_index_entry[] = {
410    { MATROSKA_ID_CUETIME,            EBML_UINT, 0, offsetof(MatroskaIndex,time) },
411    { MATROSKA_ID_CUETRACKPOSITION,   EBML_NEST, sizeof(MatroskaIndexPos), offsetof(MatroskaIndex,pos), {.n=matroska_index_pos} },
412    { 0 }
413};
414
415static EbmlSyntax matroska_index[] = {
416    { MATROSKA_ID_POINTENTRY,         EBML_NEST, sizeof(MatroskaIndex), offsetof(MatroskaDemuxContext,index), {.n=matroska_index_entry} },
417    { 0 }
418};
419
420static EbmlSyntax matroska_simpletag[] = {
421    { MATROSKA_ID_TAGNAME,            EBML_UTF8, 0, offsetof(MatroskaTag,name) },
422    { MATROSKA_ID_TAGSTRING,          EBML_UTF8, 0, offsetof(MatroskaTag,string) },
423    { MATROSKA_ID_TAGLANG,            EBML_STR,  0, offsetof(MatroskaTag,lang), {.s="und"} },
424    { MATROSKA_ID_TAGDEFAULT,         EBML_UINT, 0, offsetof(MatroskaTag,def) },
425    { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTag,sub), {.n=matroska_simpletag} },
426    { 0 }
427};
428
429static EbmlSyntax matroska_tagtargets[] = {
430    { MATROSKA_ID_TAGTARGETS_TYPE,      EBML_STR,  0, offsetof(MatroskaTagTarget,type) },
431    { MATROSKA_ID_TAGTARGETS_TYPEVALUE, EBML_UINT, 0, offsetof(MatroskaTagTarget,typevalue), {.u=50} },
432    { MATROSKA_ID_TAGTARGETS_TRACKUID,  EBML_UINT, 0, offsetof(MatroskaTagTarget,trackuid) },
433    { MATROSKA_ID_TAGTARGETS_CHAPTERUID,EBML_UINT, 0, offsetof(MatroskaTagTarget,chapteruid) },
434    { MATROSKA_ID_TAGTARGETS_ATTACHUID, EBML_UINT, 0, offsetof(MatroskaTagTarget,attachuid) },
435    { 0 }
436};
437
438static EbmlSyntax matroska_tag[] = {
439    { MATROSKA_ID_SIMPLETAG,          EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTags,tag), {.n=matroska_simpletag} },
440    { MATROSKA_ID_TAGTARGETS,         EBML_NEST, 0, offsetof(MatroskaTags,target), {.n=matroska_tagtargets} },
441    { 0 }
442};
443
444static EbmlSyntax matroska_tags[] = {
445    { MATROSKA_ID_TAG,                EBML_NEST, sizeof(MatroskaTags), offsetof(MatroskaDemuxContext,tags), {.n=matroska_tag} },
446    { 0 }
447};
448
449static EbmlSyntax matroska_seekhead_entry[] = {
450    { MATROSKA_ID_SEEKID,             EBML_UINT, 0, offsetof(MatroskaSeekhead,id) },
451    { MATROSKA_ID_SEEKPOSITION,       EBML_UINT, 0, offsetof(MatroskaSeekhead,pos), {.u=-1} },
452    { 0 }
453};
454
455static EbmlSyntax matroska_seekhead[] = {
456    { MATROSKA_ID_SEEKENTRY,          EBML_NEST, sizeof(MatroskaSeekhead), offsetof(MatroskaDemuxContext,seekhead), {.n=matroska_seekhead_entry} },
457    { 0 }
458};
459
460static EbmlSyntax matroska_segment[] = {
461    { MATROSKA_ID_INFO,           EBML_NEST, 0, 0, {.n=matroska_info       } },
462    { MATROSKA_ID_TRACKS,         EBML_NEST, 0, 0, {.n=matroska_tracks     } },
463    { MATROSKA_ID_ATTACHMENTS,    EBML_NEST, 0, 0, {.n=matroska_attachments} },
464    { MATROSKA_ID_CHAPTERS,       EBML_NEST, 0, 0, {.n=matroska_chapters   } },
465    { MATROSKA_ID_CUES,           EBML_NEST, 0, 0, {.n=matroska_index      } },
466    { MATROSKA_ID_TAGS,           EBML_NEST, 0, 0, {.n=matroska_tags       } },
467    { MATROSKA_ID_SEEKHEAD,       EBML_NEST, 0, 0, {.n=matroska_seekhead   } },
468    { MATROSKA_ID_CLUSTER,        EBML_STOP, 0, offsetof(MatroskaDemuxContext,has_cluster_id) },
469    { 0 }
470};
471
472static EbmlSyntax matroska_segments[] = {
473    { MATROSKA_ID_SEGMENT,        EBML_NEST, 0, 0, {.n=matroska_segment    } },
474    { 0 }
475};
476
477static EbmlSyntax matroska_blockgroup[] = {
478    { MATROSKA_ID_BLOCK,          EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
479    { MATROSKA_ID_SIMPLEBLOCK,    EBML_BIN,  0, offsetof(MatroskaBlock,bin) },
480    { MATROSKA_ID_BLOCKDURATION,  EBML_UINT, 0, offsetof(MatroskaBlock,duration), {.u=AV_NOPTS_VALUE} },
481    { MATROSKA_ID_BLOCKREFERENCE, EBML_UINT, 0, offsetof(MatroskaBlock,reference) },
482    { 0 }
483};
484
485static EbmlSyntax matroska_cluster[] = {
486    { MATROSKA_ID_CLUSTERTIMECODE,EBML_UINT,0, offsetof(MatroskaCluster,timecode) },
487    { MATROSKA_ID_BLOCKGROUP,     EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
488    { MATROSKA_ID_SIMPLEBLOCK,    EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster,blocks), {.n=matroska_blockgroup} },
489    { MATROSKA_ID_CLUSTERPOSITION,EBML_NONE },
490    { MATROSKA_ID_CLUSTERPREVSIZE,EBML_NONE },
491    { 0 }
492};
493
494static EbmlSyntax matroska_clusters[] = {
495    { MATROSKA_ID_CLUSTER,        EBML_NEST, 0, 0, {.n=matroska_cluster} },
496    { MATROSKA_ID_INFO,           EBML_NONE },
497    { MATROSKA_ID_CUES,           EBML_NONE },
498    { MATROSKA_ID_TAGS,           EBML_NONE },
499    { MATROSKA_ID_SEEKHEAD,       EBML_NONE },
500    { 0 }
501};
502
503/*
504 * Return: Whether we reached the end of a level in the hierarchy or not.
505 */
506static int ebml_level_end(MatroskaDemuxContext *matroska)
507{
508    ByteIOContext *pb = matroska->ctx->pb;
509    int64_t pos = url_ftell(pb);
510
511    if (matroska->num_levels > 0) {
512        MatroskaLevel *level = &matroska->levels[matroska->num_levels - 1];
513        if (pos - level->start >= level->length) {
514            matroska->num_levels--;
515            return 1;
516        }
517    }
518    return 0;
519}
520
521/*
522 * Read: an "EBML number", which is defined as a variable-length
523 * array of bytes. The first byte indicates the length by giving a
524 * number of 0-bits followed by a one. The position of the first
525 * "one" bit inside the first byte indicates the length of this
526 * number.
527 * Returns: number of bytes read, < 0 on error
528 */
529static int ebml_read_num(MatroskaDemuxContext *matroska, ByteIOContext *pb,
530                         int max_size, uint64_t *number)
531{
532    int len_mask = 0x80, read = 1, n = 1;
533    int64_t total = 0;
534
535    /* The first byte tells us the length in bytes - get_byte() can normally
536     * return 0, but since that's not a valid first ebmlID byte, we can
537     * use it safely here to catch EOS. */
538    if (!(total = get_byte(pb))) {
539        /* we might encounter EOS here */
540        if (!url_feof(pb)) {
541            int64_t pos = url_ftell(pb);
542            av_log(matroska->ctx, AV_LOG_ERROR,
543                   "Read error at pos. %"PRIu64" (0x%"PRIx64")\n",
544                   pos, pos);
545        }
546        return AVERROR(EIO); /* EOS or actual I/O error */
547    }
548
549    /* get the length of the EBML number */
550    while (read <= max_size && !(total & len_mask)) {
551        read++;
552        len_mask >>= 1;
553    }
554    if (read > max_size) {
555        int64_t pos = url_ftell(pb) - 1;
556        av_log(matroska->ctx, AV_LOG_ERROR,
557               "Invalid EBML number size tag 0x%02x at pos %"PRIu64" (0x%"PRIx64")\n",
558               (uint8_t) total, pos, pos);
559        return AVERROR_INVALIDDATA;
560    }
561
562    /* read out length */
563    total &= ~len_mask;
564    while (n++ < read)
565        total = (total << 8) | get_byte(pb);
566
567    *number = total;
568
569    return read;
570}
571
572/*
573 * Read the next element as an unsigned int.
574 * 0 is success, < 0 is failure.
575 */
576static int ebml_read_uint(ByteIOContext *pb, int size, uint64_t *num)
577{
578    int n = 0;
579
580    if (size < 1 || size > 8)
581        return AVERROR_INVALIDDATA;
582
583    /* big-endian ordering; build up number */
584    *num = 0;
585    while (n++ < size)
586        *num = (*num << 8) | get_byte(pb);
587
588    return 0;
589}
590
591/*
592 * Read the next element as a float.
593 * 0 is success, < 0 is failure.
594 */
595static int ebml_read_float(ByteIOContext *pb, int size, double *num)
596{
597    if (size == 4) {
598        *num= av_int2flt(get_be32(pb));
599    } else if(size==8){
600        *num= av_int2dbl(get_be64(pb));
601    } else
602        return AVERROR_INVALIDDATA;
603
604    return 0;
605}
606
607/*
608 * Read the next element as an ASCII string.
609 * 0 is success, < 0 is failure.
610 */
611static int ebml_read_ascii(ByteIOContext *pb, int size, char **str)
612{
613    av_free(*str);
614    /* EBML strings are usually not 0-terminated, so we allocate one
615     * byte more, read the string and NULL-terminate it ourselves. */
616	*str = av_malloc(size + 1);
617    if (!(*str))
618        return AVERROR(ENOMEM);
619    if (get_buffer(pb, (uint8_t *) *str, size) != size) {
620        av_free(*str);
621        return AVERROR(EIO);
622    }
623    (*str)[size] = '\0';
624
625    return 0;
626}
627
628/*
629 * Read the next element as binary data.
630 * 0 is success, < 0 is failure.
631 */
632static int ebml_read_binary(ByteIOContext *pb, int length, EbmlBin *bin)
633{
634    av_free(bin->data);
635	bin->data = av_malloc(length);
636    if (!(bin->data))
637        return AVERROR(ENOMEM);
638
639    bin->size = length;
640    bin->pos  = url_ftell(pb);
641    if (get_buffer(pb, bin->data, length) != length)
642        return AVERROR(EIO);
643
644    return 0;
645}
646
647/*
648 * Read the next element, but only the header. The contents
649 * are supposed to be sub-elements which can be read separately.
650 * 0 is success, < 0 is failure.
651 */
652static int ebml_read_master(MatroskaDemuxContext *matroska, int length)
653{
654    ByteIOContext *pb = matroska->ctx->pb;
655    MatroskaLevel *level;
656
657    if (matroska->num_levels >= EBML_MAX_DEPTH) {
658        av_log(matroska->ctx, AV_LOG_ERROR,
659               "File moves beyond max. allowed depth (%d)\n", EBML_MAX_DEPTH);
660        return AVERROR(ENOSYS);
661    }
662
663    level = &matroska->levels[matroska->num_levels++];
664    level->start = url_ftell(pb);
665    level->length = length;
666
667    return 0;
668}
669
670/*
671 * Read signed/unsigned "EBML" numbers.
672 * Return: number of bytes processed, < 0 on error
673 */
674static int matroska_ebmlnum_uint(MatroskaDemuxContext *matroska,
675                                 uint8_t *data, uint32_t size, uint64_t *num)
676{
677    ByteIOContext pb;
678    init_put_byte(&pb, data, size, 0, NULL, NULL, NULL, NULL);
679    return ebml_read_num(matroska, &pb, 8, num);
680}
681
682/*
683 * Same as above, but signed.
684 */
685static int matroska_ebmlnum_sint(MatroskaDemuxContext *matroska,
686                                 uint8_t *data, uint32_t size, int64_t *num)
687{
688    uint64_t unum;
689    int res;
690
691    /* read as unsigned number first */
692    if ((res = matroska_ebmlnum_uint(matroska, data, size, &unum)) < 0)
693        return res;
694
695    /* make signed (weird way) */
696    *num = unum - ((1LL << (7*res - 1)) - 1);
697
698    return res;
699}
700
701static int ebml_parse_elem(MatroskaDemuxContext *matroska,
702                           EbmlSyntax *syntax, void *data);
703
704static int ebml_parse_id(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
705                         uint32_t id, void *data)
706{
707    int i;
708    for (i=0; syntax[i].id; i++)
709        if (id == syntax[i].id)
710            break;
711    if (!syntax[i].id && id != EBML_ID_VOID && id != EBML_ID_CRC32)
712        av_log(matroska->ctx, AV_LOG_INFO, "Unknown entry 0x%X\n", id);
713    return ebml_parse_elem(matroska, &syntax[i], data);
714}
715
716static int ebml_parse(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
717                      void *data)
718{
719    uint64_t id;
720    int res = ebml_read_num(matroska, matroska->ctx->pb, 4, &id);
721    id |= 1 << 7*res;
722    return res < 0 ? res : ebml_parse_id(matroska, syntax, id, data);
723}
724
725static int ebml_parse_nest(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
726                           void *data)
727{
728    int i, res = 0;
729
730    for (i=0; syntax[i].id; i++)
731        switch (syntax[i].type) {
732        case EBML_UINT:
733            *(uint64_t *)((char *)data+syntax[i].data_offset) = syntax[i].def.u;
734            break;
735        case EBML_FLOAT:
736            *(double   *)((char *)data+syntax[i].data_offset) = syntax[i].def.f;
737            break;
738        case EBML_STR:
739        case EBML_UTF8:
740            *(char    **)((char *)data+syntax[i].data_offset) = av_strdup(syntax[i].def.s);
741            break;
742        }
743
744    while (!res && !ebml_level_end(matroska))
745        res = ebml_parse(matroska, syntax, data);
746
747    return res;
748}
749
750static int ebml_parse_elem(MatroskaDemuxContext *matroska,
751                           EbmlSyntax *syntax, void *data)
752{
753    ByteIOContext *pb = matroska->ctx->pb;
754    uint32_t id = syntax->id;
755    uint64_t length;
756    int res;
757
758    data = (char *)data + syntax->data_offset;
759    if (syntax->list_elem_size) {
760        EbmlList *list = data;
761        list->elem = av_realloc(list->elem, (list->nb_elem+1)*syntax->list_elem_size);
762        data = (char*)list->elem + list->nb_elem*syntax->list_elem_size;
763        memset(data, 0, syntax->list_elem_size);
764        list->nb_elem++;
765    }
766
767    if (syntax->type != EBML_PASS && syntax->type != EBML_STOP)
768        if ((res = ebml_read_num(matroska, pb, 8, &length)) < 0)
769            return res;
770
771    switch (syntax->type) {
772    case EBML_UINT:  res = ebml_read_uint  (pb, length, data);  break;
773    case EBML_FLOAT: res = ebml_read_float (pb, length, data);  break;
774    case EBML_STR:
775    case EBML_UTF8:  res = ebml_read_ascii (pb, length, data);  break;
776    case EBML_BIN:   res = ebml_read_binary(pb, length, data);  break;
777    case EBML_NEST:  if ((res=ebml_read_master(matroska, length)) < 0)
778                         return res;
779                     if (id == MATROSKA_ID_SEGMENT)
780                         matroska->segment_start = url_ftell(matroska->ctx->pb);
781                     return ebml_parse_nest(matroska, syntax->def.n, data);
782    case EBML_PASS:  return ebml_parse_id(matroska, syntax->def.n, id, data);
783    case EBML_STOP:  *(int *)data = 1;      return 1;
784    default:         return url_fseek(pb,length,SEEK_CUR)<0 ? AVERROR(EIO) : 0;
785    }
786    if (res == AVERROR_INVALIDDATA)
787        av_log(matroska->ctx, AV_LOG_ERROR, "Invalid element\n");
788    else if (res == AVERROR(EIO))
789        av_log(matroska->ctx, AV_LOG_ERROR, "Read error\n");
790    return res;
791}
792
793static void ebml_free(EbmlSyntax *syntax, void *data)
794{
795    int i, j;
796    for (i=0; syntax[i].id; i++) {
797        void *data_off = (char *)data + syntax[i].data_offset;
798        switch (syntax[i].type) {
799        case EBML_STR:
800        case EBML_UTF8:  av_freep(data_off);                      break;
801        case EBML_BIN:   av_freep(&((EbmlBin *)data_off)->data);  break;
802        case EBML_NEST:
803            if (syntax[i].list_elem_size) {
804                EbmlList *list = data_off;
805                char *ptr = list->elem;
806                for (j=0; j<list->nb_elem; j++, ptr+=syntax[i].list_elem_size)
807                    ebml_free(syntax[i].def.n, ptr);
808                av_free(list->elem);
809            } else
810                ebml_free(syntax[i].def.n, data_off);
811        default:  break;
812        }
813    }
814}
815
816
817/*
818 * Autodetecting...
819 */
820static int matroska_probe(AVProbeData *p)
821{
822    uint64_t total = 0;
823    int len_mask = 0x80, size = 1, n = 1;
824    static const char probe_data[] = "matroska";
825
826    /* EBML header? */
827    if (AV_RB32(p->buf) != EBML_ID_HEADER)
828        return 0;
829
830    /* length of header */
831    total = p->buf[4];
832    while (size <= 8 && !(total & len_mask)) {
833        size++;
834        len_mask >>= 1;
835    }
836    if (size > 8)
837      return 0;
838    total &= (len_mask - 1);
839    while (n < size)
840        total = (total << 8) | p->buf[4 + n++];
841
842    /* Does the probe data contain the whole header? */
843    if (p->buf_size < 4 + size + total)
844      return 0;
845
846    /* The header must contain the document type 'matroska'. For now,
847     * we don't parse the whole header but simply check for the
848     * availability of that array of characters inside the header.
849     * Not fully fool-proof, but good enough. */
850    for (n = 4+size; n <= 4+size+total-(sizeof(probe_data)-1); n++)
851        if (!memcmp(p->buf+n, probe_data, sizeof(probe_data)-1))
852            return AVPROBE_SCORE_MAX;
853
854    return 0;
855}
856
857static MatroskaTrack *matroska_find_track_by_num(MatroskaDemuxContext *matroska,
858                                                 int num)
859{
860    MatroskaTrack *tracks = matroska->tracks.elem;
861    int i;
862
863    for (i=0; i < matroska->tracks.nb_elem; i++)
864        if (tracks[i].num == num)
865            return &tracks[i];
866
867    av_log(matroska->ctx, AV_LOG_ERROR, "Invalid track number %d\n", num);
868    return NULL;
869}
870
871static int matroska_decode_buffer(uint8_t** buf, int* buf_size,
872                                  MatroskaTrack *track)
873{
874    MatroskaTrackEncoding *encodings = track->encodings.elem;
875    uint8_t* data = *buf;
876    int isize = *buf_size;
877    uint8_t* pkt_data = NULL;
878    int pkt_size = isize;
879    int result = 0;
880    int olen;
881
882    switch (encodings[0].compression.algo) {
883    case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP:
884        return encodings[0].compression.settings.size;
885    case MATROSKA_TRACK_ENCODING_COMP_LZO:
886        do {
887            olen = pkt_size *= 3;
888            pkt_data = av_realloc(pkt_data, pkt_size+AV_LZO_OUTPUT_PADDING);
889            result = av_lzo1x_decode(pkt_data, &olen, data, &isize);
890        } while (result==AV_LZO_OUTPUT_FULL && pkt_size<10000000);
891        if (result)
892            goto failed;
893        pkt_size -= olen;
894        break;
895#if CONFIG_ZLIB
896    case MATROSKA_TRACK_ENCODING_COMP_ZLIB: {
897        z_stream zstream = {0};
898        if (inflateInit(&zstream) != Z_OK)
899            return -1;
900        zstream.next_in = data;
901        zstream.avail_in = isize;
902        do {
903            pkt_size *= 3;
904            pkt_data = av_realloc(pkt_data, pkt_size);
905            zstream.avail_out = pkt_size - zstream.total_out;
906            zstream.next_out = pkt_data + zstream.total_out;
907            result = inflate(&zstream, Z_NO_FLUSH);
908        } while (result==Z_OK && pkt_size<10000000);
909        pkt_size = zstream.total_out;
910        inflateEnd(&zstream);
911        if (result != Z_STREAM_END)
912            goto failed;
913        break;
914    }
915#endif
916#if CONFIG_BZLIB
917    case MATROSKA_TRACK_ENCODING_COMP_BZLIB: {
918        bz_stream bzstream = {0};
919        if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
920            return -1;
921        bzstream.next_in = data;
922        bzstream.avail_in = isize;
923        do {
924            pkt_size *= 3;
925            pkt_data = av_realloc(pkt_data, pkt_size);
926            bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
927            bzstream.next_out = pkt_data + bzstream.total_out_lo32;
928            result = BZ2_bzDecompress(&bzstream);
929        } while (result==BZ_OK && pkt_size<10000000);
930        pkt_size = bzstream.total_out_lo32;
931        BZ2_bzDecompressEnd(&bzstream);
932        if (result != BZ_STREAM_END)
933            goto failed;
934        break;
935    }
936#endif
937    default:
938        return -1;
939    }
940
941    *buf = pkt_data;
942    *buf_size = pkt_size;
943    return 0;
944 failed:
945    av_free(pkt_data);
946    return -1;
947}
948
949static void matroska_fix_ass_packet(MatroskaDemuxContext *matroska,
950                                    AVPacket *pkt, uint64_t display_duration)
951{
952    char *line, *layer, *ptr = pkt->data, *end = ptr+pkt->size;
953    for (; *ptr!=',' && ptr<end-1; ptr++);
954    if (*ptr == ',')
955        layer = ++ptr;
956    for (; *ptr!=',' && ptr<end-1; ptr++);
957    if (*ptr == ',') {
958        int64_t end_pts = pkt->pts + display_duration;
959        int sc = matroska->time_scale * pkt->pts / 10000000;
960        int ec = matroska->time_scale * end_pts  / 10000000;
961        int sh, sm, ss, eh, em, es, len;
962        sh = sc/360000;  sc -= 360000*sh;
963        sm = sc/  6000;  sc -=   6000*sm;
964        ss = sc/   100;  sc -=    100*ss;
965        eh = ec/360000;  ec -= 360000*eh;
966        em = ec/  6000;  ec -=   6000*em;
967        es = ec/   100;  ec -=    100*es;
968        *ptr++ = '\0';
969        len = 50 + end-ptr + FF_INPUT_BUFFER_PADDING_SIZE;
970		line = av_malloc(len);
971        if (!(line))
972            return;
973        snprintf(line,len,"Dialogue: %s,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s\r\n",
974                 layer, sh, sm, ss, sc, eh, em, es, ec, ptr);
975        av_free(pkt->data);
976        pkt->data = line;
977        pkt->size = strlen(line);
978    }
979}
980
981static void matroska_merge_packets(AVPacket *out, AVPacket *in)
982{
983    out->data = av_realloc(out->data, out->size+in->size);
984    memcpy(out->data+out->size, in->data, in->size);
985    out->size += in->size;
986    av_destruct_packet(in);
987    av_free(in);
988}
989
990static void matroska_convert_tag(AVFormatContext *s, EbmlList *list,
991                                 AVMetadata **metadata, char *prefix)
992{
993    MatroskaTag *tags = list->elem;
994    char key[1024];
995    int i;
996
997    for (i=0; i < list->nb_elem; i++) {
998        const char *lang = strcmp(tags[i].lang, "und") ? tags[i].lang : NULL;
999        if (prefix)  snprintf(key, sizeof(key), "%s/%s", prefix, tags[i].name);
1000        else         av_strlcpy(key, tags[i].name, sizeof(key));
1001        if (tags[i].def || !lang) {
1002        av_metadata_set(metadata, key, tags[i].string);
1003        if (tags[i].sub.nb_elem)
1004            matroska_convert_tag(s, &tags[i].sub, metadata, key);
1005        }
1006        if (lang) {
1007            av_strlcat(key, "-", sizeof(key));
1008            av_strlcat(key, lang, sizeof(key));
1009            av_metadata_set(metadata, key, tags[i].string);
1010            if (tags[i].sub.nb_elem)
1011                matroska_convert_tag(s, &tags[i].sub, metadata, key);
1012        }
1013    }
1014}
1015
1016static void matroska_convert_tags(AVFormatContext *s)
1017{
1018    MatroskaDemuxContext *matroska = s->priv_data;
1019    MatroskaTags *tags = matroska->tags.elem;
1020    int i, j;
1021
1022    for (i=0; i < matroska->tags.nb_elem; i++) {
1023        if (tags[i].target.attachuid) {
1024            MatroskaAttachement *attachment = matroska->attachments.elem;
1025            for (j=0; j<matroska->attachments.nb_elem; j++)
1026                if (attachment[j].uid == tags[i].target.attachuid)
1027                    matroska_convert_tag(s, &tags[i].tag,
1028                                         &attachment[j].stream->metadata, NULL);
1029        } else if (tags[i].target.chapteruid) {
1030            MatroskaChapter *chapter = matroska->chapters.elem;
1031            for (j=0; j<matroska->chapters.nb_elem; j++)
1032                if (chapter[j].uid == tags[i].target.chapteruid)
1033                    matroska_convert_tag(s, &tags[i].tag,
1034                                         &chapter[j].chapter->metadata, NULL);
1035        } else if (tags[i].target.trackuid) {
1036            MatroskaTrack *track = matroska->tracks.elem;
1037            for (j=0; j<matroska->tracks.nb_elem; j++)
1038                if (track[j].uid == tags[i].target.trackuid)
1039                    matroska_convert_tag(s, &tags[i].tag,
1040                                         &track[j].stream->metadata, NULL);
1041        } else {
1042            matroska_convert_tag(s, &tags[i].tag, &s->metadata, NULL);
1043        }
1044    }
1045}
1046
1047static void matroska_execute_seekhead(MatroskaDemuxContext *matroska)
1048{
1049    EbmlList *seekhead_list = &matroska->seekhead;
1050    MatroskaSeekhead *seekhead = seekhead_list->elem;
1051    uint32_t level_up = matroska->level_up;
1052    int64_t before_pos = url_ftell(matroska->ctx->pb);
1053    MatroskaLevel level;
1054    int i;
1055
1056    for (i=0; i<seekhead_list->nb_elem; i++) {
1057        int64_t offset = seekhead[i].pos + matroska->segment_start;
1058
1059        if (seekhead[i].pos <= before_pos
1060            || seekhead[i].id == MATROSKA_ID_SEEKHEAD
1061            || seekhead[i].id == MATROSKA_ID_CLUSTER)
1062            continue;
1063
1064        /* seek */
1065        if (url_fseek(matroska->ctx->pb, offset, SEEK_SET) != offset)
1066            continue;
1067
1068        /* We don't want to lose our seekhead level, so we add
1069         * a dummy. This is a crude hack. */
1070        if (matroska->num_levels == EBML_MAX_DEPTH) {
1071            av_log(matroska->ctx, AV_LOG_INFO,
1072                   "Max EBML element depth (%d) reached, "
1073                   "cannot parse further.\n", EBML_MAX_DEPTH);
1074            break;
1075        }
1076
1077        level.start = 0;
1078        level.length = (uint64_t)-1;
1079        matroska->levels[matroska->num_levels] = level;
1080        matroska->num_levels++;
1081
1082        ebml_parse(matroska, matroska_segment, matroska);
1083
1084        /* remove dummy level */
1085        while (matroska->num_levels) {
1086            uint64_t length = matroska->levels[--matroska->num_levels].length;
1087            if (length == (uint64_t)-1)
1088                break;
1089        }
1090    }
1091
1092    /* seek back */
1093    url_fseek(matroska->ctx->pb, before_pos, SEEK_SET);
1094    matroska->level_up = level_up;
1095}
1096
1097static int matroska_aac_profile(char *codec_id)
1098{
1099    static const char * const aac_profiles[] = { "MAIN", "LC", "SSR" };
1100    int profile;
1101
1102    for (profile=0; profile<FF_ARRAY_ELEMS(aac_profiles); profile++)
1103        if (strstr(codec_id, aac_profiles[profile]))
1104            break;
1105    return profile + 1;
1106}
1107
1108static int matroska_aac_sri(int samplerate)
1109{
1110    int sri;
1111
1112    for (sri=0; sri<FF_ARRAY_ELEMS(ff_mpeg4audio_sample_rates); sri++)
1113        if (ff_mpeg4audio_sample_rates[sri] == samplerate)
1114            break;
1115    return sri;
1116}
1117
1118static int matroska_read_header(AVFormatContext *s, AVFormatParameters *ap)
1119{
1120    MatroskaDemuxContext *matroska = s->priv_data;
1121    EbmlList *attachements_list = &matroska->attachments;
1122    MatroskaAttachement *attachements;
1123    EbmlList *chapters_list = &matroska->chapters;
1124    MatroskaChapter *chapters;
1125    MatroskaTrack *tracks;
1126    EbmlList *index_list;
1127    MatroskaIndex *index;
1128    int index_scale = 1;
1129    uint64_t max_start = 0;
1130    Ebml ebml = { 0 };
1131    AVStream *st;
1132    int i, j;
1133
1134    matroska->ctx = s;
1135
1136    /* First read the EBML header. */
1137    if (ebml_parse(matroska, ebml_syntax, &ebml)
1138        || ebml.version > EBML_VERSION       || ebml.max_size > sizeof(uint64_t)
1139        || ebml.id_length > sizeof(uint32_t) || strcmp(ebml.doctype, "matroska")
1140        || ebml.doctype_version > 2) {
1141        av_log(matroska->ctx, AV_LOG_ERROR,
1142               "EBML header using unsupported features\n"
1143               "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
1144               ebml.version, ebml.doctype, ebml.doctype_version);
1145        return AVERROR_NOFMT;
1146    }
1147    ebml_free(ebml_syntax, &ebml);
1148
1149    /* The next thing is a segment. */
1150    if (ebml_parse(matroska, matroska_segments, matroska) < 0)
1151        return -1;
1152    matroska_execute_seekhead(matroska);
1153
1154    if (matroska->duration)
1155        matroska->ctx->duration = matroska->duration * matroska->time_scale
1156                                  * 1000 / AV_TIME_BASE;
1157    av_metadata_set(&s->metadata, "title", matroska->title);
1158
1159    tracks = matroska->tracks.elem;
1160    for (i=0; i < matroska->tracks.nb_elem; i++) {
1161        MatroskaTrack *track = &tracks[i];
1162        enum CodecID codec_id = CODEC_ID_NONE;
1163        EbmlList *encodings_list = &tracks->encodings;
1164        MatroskaTrackEncoding *encodings = encodings_list->elem;
1165        uint8_t *extradata = NULL;
1166        int extradata_size = 0;
1167        int extradata_offset = 0;
1168        ByteIOContext b;
1169
1170        /* Apply some sanity checks. */
1171        if (track->type != MATROSKA_TRACK_TYPE_VIDEO &&
1172            track->type != MATROSKA_TRACK_TYPE_AUDIO &&
1173            track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
1174            av_log(matroska->ctx, AV_LOG_INFO,
1175                   "Unknown or unsupported track type %"PRIu64"\n",
1176                   track->type);
1177            continue;
1178        }
1179        if (track->codec_id == NULL)
1180            continue;
1181
1182        if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1183            if (!track->default_duration)
1184                track->default_duration = 1000000000/track->video.frame_rate;
1185            if (!track->video.display_width)
1186                track->video.display_width = track->video.pixel_width;
1187            if (!track->video.display_height)
1188                track->video.display_height = track->video.pixel_height;
1189        } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1190            if (!track->audio.out_samplerate)
1191                track->audio.out_samplerate = track->audio.samplerate;
1192        }
1193        if (encodings_list->nb_elem > 1) {
1194            av_log(matroska->ctx, AV_LOG_ERROR,
1195                   "Multiple combined encodings no supported");
1196        } else if (encodings_list->nb_elem == 1) {
1197            if (encodings[0].type ||
1198                (encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP &&
1199#if CONFIG_ZLIB
1200                 encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_ZLIB &&
1201#endif
1202#if CONFIG_BZLIB
1203                 encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_BZLIB &&
1204#endif
1205                 encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_LZO)) {
1206                encodings[0].scope = 0;
1207                av_log(matroska->ctx, AV_LOG_ERROR,
1208                       "Unsupported encoding type");
1209            } else if (track->codec_priv.size && encodings[0].scope&2) {
1210                uint8_t *codec_priv = track->codec_priv.data;
1211                int offset = matroska_decode_buffer(&track->codec_priv.data,
1212                                                    &track->codec_priv.size,
1213                                                    track);
1214                if (offset < 0) {
1215                    track->codec_priv.data = NULL;
1216                    track->codec_priv.size = 0;
1217                    av_log(matroska->ctx, AV_LOG_ERROR,
1218                           "Failed to decode codec private data\n");
1219                } else if (offset > 0) {
1220                    track->codec_priv.data = av_malloc(track->codec_priv.size + offset);
1221                    memcpy(track->codec_priv.data,
1222                           encodings[0].compression.settings.data, offset);
1223                    memcpy(track->codec_priv.data+offset, codec_priv,
1224                           track->codec_priv.size);
1225                    track->codec_priv.size += offset;
1226                }
1227                if (codec_priv != track->codec_priv.data)
1228                    av_free(codec_priv);
1229            }
1230        }
1231
1232        for(j=0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++){
1233            if(!strncmp(ff_mkv_codec_tags[j].str, track->codec_id,
1234                        strlen(ff_mkv_codec_tags[j].str))){
1235                codec_id= ff_mkv_codec_tags[j].id;
1236                break;
1237            }
1238        }
1239
1240        st = track->stream = av_new_stream(s, 0);
1241        if (st == NULL)
1242            return AVERROR(ENOMEM);
1243
1244        if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC")
1245            && track->codec_priv.size >= 40
1246            && track->codec_priv.data != NULL) {
1247            track->video.fourcc = AV_RL32(track->codec_priv.data + 16);
1248            codec_id = codec_get_id(codec_bmp_tags, track->video.fourcc);
1249        } else if (!strcmp(track->codec_id, "A_MS/ACM")
1250                   && track->codec_priv.size >= 18
1251                   && track->codec_priv.data != NULL) {
1252            init_put_byte(&b, track->codec_priv.data, track->codec_priv.size,
1253                          URL_RDONLY, NULL, NULL, NULL, NULL);
1254            get_wav_header(&b, st->codec, track->codec_priv.size);
1255            codec_id = st->codec->codec_id;
1256            extradata_offset = 18;
1257            track->codec_priv.size -= extradata_offset;
1258        } else if (!strcmp(track->codec_id, "V_QUICKTIME")
1259                   && (track->codec_priv.size >= 86)
1260                   && (track->codec_priv.data != NULL)) {
1261            track->video.fourcc = AV_RL32(track->codec_priv.data);
1262            codec_id=codec_get_id(codec_movvideo_tags, track->video.fourcc);
1263        } else if (codec_id == CODEC_ID_PCM_S16BE) {
1264            switch (track->audio.bitdepth) {
1265            case  8:  codec_id = CODEC_ID_PCM_U8;     break;
1266            case 24:  codec_id = CODEC_ID_PCM_S24BE;  break;
1267            case 32:  codec_id = CODEC_ID_PCM_S32BE;  break;
1268            }
1269        } else if (codec_id == CODEC_ID_PCM_S16LE) {
1270            switch (track->audio.bitdepth) {
1271            case  8:  codec_id = CODEC_ID_PCM_U8;     break;
1272            case 24:  codec_id = CODEC_ID_PCM_S24LE;  break;
1273            case 32:  codec_id = CODEC_ID_PCM_S32LE;  break;
1274            }
1275        } else if (codec_id==CODEC_ID_PCM_F32LE && track->audio.bitdepth==64) {
1276            codec_id = CODEC_ID_PCM_F64LE;
1277        } else if (codec_id == CODEC_ID_AAC && !track->codec_priv.size) {
1278            int profile = matroska_aac_profile(track->codec_id);
1279            int sri = matroska_aac_sri(track->audio.samplerate);
1280            extradata = av_malloc(5);
1281            if (extradata == NULL)
1282                return AVERROR(ENOMEM);
1283            extradata[0] = (profile << 3) | ((sri&0x0E) >> 1);
1284            extradata[1] = ((sri&0x01) << 7) | (track->audio.channels<<3);
1285            if (strstr(track->codec_id, "SBR")) {
1286                sri = matroska_aac_sri(track->audio.out_samplerate);
1287                extradata[2] = 0x56;
1288                extradata[3] = 0xE5;
1289                extradata[4] = 0x80 | (sri<<3);
1290                extradata_size = 5;
1291            } else
1292                extradata_size = 2;
1293        } else if (codec_id == CODEC_ID_TTA) {
1294            extradata_size = 30;
1295            extradata = av_mallocz(extradata_size);
1296            if (extradata == NULL)
1297                return AVERROR(ENOMEM);
1298            init_put_byte(&b, extradata, extradata_size, 1,
1299                          NULL, NULL, NULL, NULL);
1300            put_buffer(&b, "TTA1", 4);
1301            put_le16(&b, 1);
1302            put_le16(&b, track->audio.channels);
1303            put_le16(&b, track->audio.bitdepth);
1304            put_le32(&b, track->audio.out_samplerate);
1305            put_le32(&b, matroska->ctx->duration * track->audio.out_samplerate);
1306        } else if (codec_id == CODEC_ID_RV10 || codec_id == CODEC_ID_RV20 ||
1307                   codec_id == CODEC_ID_RV30 || codec_id == CODEC_ID_RV40) {
1308            extradata_offset = 26;
1309            track->codec_priv.size -= extradata_offset;
1310        } else if (codec_id == CODEC_ID_RA_144) {
1311            track->audio.out_samplerate = 8000;
1312            track->audio.channels = 1;
1313        } else if (codec_id == CODEC_ID_RA_288 || codec_id == CODEC_ID_COOK ||
1314                   codec_id == CODEC_ID_ATRAC3) {
1315            init_put_byte(&b, track->codec_priv.data,track->codec_priv.size,
1316                          0, NULL, NULL, NULL, NULL);
1317            url_fskip(&b, 24);
1318            track->audio.coded_framesize = get_be32(&b);
1319            url_fskip(&b, 12);
1320            track->audio.sub_packet_h    = get_be16(&b);
1321            track->audio.frame_size      = get_be16(&b);
1322            track->audio.sub_packet_size = get_be16(&b);
1323            track->audio.buf = av_malloc(track->audio.frame_size * track->audio.sub_packet_h);
1324            if (codec_id == CODEC_ID_RA_288) {
1325                st->codec->block_align = track->audio.coded_framesize;
1326                track->codec_priv.size = 0;
1327            } else {
1328                st->codec->block_align = track->audio.sub_packet_size;
1329                extradata_offset = 78;
1330                track->codec_priv.size -= extradata_offset;
1331            }
1332        }
1333
1334        if (codec_id == CODEC_ID_NONE)
1335            av_log(matroska->ctx, AV_LOG_INFO,
1336                   "Unknown/unsupported CodecID %s.\n", track->codec_id);
1337
1338        if (track->time_scale < 0.01)
1339            track->time_scale = 1.0;
1340        av_set_pts_info(st, 64, matroska->time_scale*track->time_scale, 1000*1000*1000); /* 64 bit pts in ns */
1341
1342        st->codec->codec_id = codec_id;
1343        st->start_time = 0;
1344        if (strcmp(track->language, "und"))
1345            av_metadata_set(&st->metadata, "language", track->language);
1346        av_metadata_set(&st->metadata, "description", track->name);
1347
1348        if (track->flag_default)
1349            st->disposition |= AV_DISPOSITION_DEFAULT;
1350
1351        if (track->default_duration)
1352            av_reduce(&st->codec->time_base.num, &st->codec->time_base.den,
1353                      track->default_duration, 1000000000, 30000);
1354
1355        if(extradata){
1356            st->codec->extradata = extradata;
1357            st->codec->extradata_size = extradata_size;
1358        } else if(track->codec_priv.data && track->codec_priv.size > 0){
1359            st->codec->extradata = av_mallocz(track->codec_priv.size +
1360                                              FF_INPUT_BUFFER_PADDING_SIZE);
1361            if(st->codec->extradata == NULL)
1362                return AVERROR(ENOMEM);
1363            st->codec->extradata_size = track->codec_priv.size;
1364            memcpy(st->codec->extradata,
1365                   track->codec_priv.data + extradata_offset,
1366                   track->codec_priv.size);
1367        }
1368
1369        if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
1370            st->codec->codec_type = CODEC_TYPE_VIDEO;
1371            st->codec->codec_tag  = track->video.fourcc;
1372            st->codec->width  = track->video.pixel_width;
1373            st->codec->height = track->video.pixel_height;
1374            av_reduce(&st->sample_aspect_ratio.num,
1375                      &st->sample_aspect_ratio.den,
1376                      st->codec->height * track->video.display_width,
1377                      st->codec-> width * track->video.display_height,
1378                      255);
1379            st->need_parsing = AVSTREAM_PARSE_HEADERS;
1380        } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
1381            st->codec->codec_type = CODEC_TYPE_AUDIO;
1382            st->codec->sample_rate = track->audio.out_samplerate;
1383            st->codec->channels = track->audio.channels;
1384        } else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
1385            st->codec->codec_type = CODEC_TYPE_SUBTITLE;
1386        }
1387    }
1388
1389    attachements = attachements_list->elem;
1390    for (j=0; j<attachements_list->nb_elem; j++) {
1391        if (!(attachements[j].filename && attachements[j].mime &&
1392              attachements[j].bin.data && attachements[j].bin.size > 0)) {
1393            av_log(matroska->ctx, AV_LOG_ERROR, "incomplete attachment\n");
1394        } else {
1395            AVStream *st = av_new_stream(s, 0);
1396            if (st == NULL)
1397                break;
1398            av_metadata_set(&st->metadata, "filename",attachements[j].filename);
1399            st->codec->codec_id = CODEC_ID_NONE;
1400            st->codec->codec_type = CODEC_TYPE_ATTACHMENT;
1401            st->codec->extradata  = av_malloc(attachements[j].bin.size);
1402            if(st->codec->extradata == NULL)
1403                break;
1404            st->codec->extradata_size = attachements[j].bin.size;
1405            memcpy(st->codec->extradata, attachements[j].bin.data, attachements[j].bin.size);
1406
1407            for (i=0; ff_mkv_mime_tags[i].id != CODEC_ID_NONE; i++) {
1408                if (!strncmp(ff_mkv_mime_tags[i].str, attachements[j].mime,
1409                             strlen(ff_mkv_mime_tags[i].str))) {
1410                    st->codec->codec_id = ff_mkv_mime_tags[i].id;
1411                    break;
1412                }
1413            }
1414            attachements[j].stream = st;
1415        }
1416    }
1417
1418    chapters = chapters_list->elem;
1419    for (i=0; i<chapters_list->nb_elem; i++)
1420        if (chapters[i].start != AV_NOPTS_VALUE && chapters[i].uid
1421            && (max_start==0 || chapters[i].start > max_start)) {
1422            chapters[i].chapter =
1423            ff_new_chapter(s, chapters[i].uid, (AVRational){1, 1000000000},
1424                           chapters[i].start, chapters[i].end,
1425                           chapters[i].title);
1426            av_metadata_set(&chapters[i].chapter->metadata,
1427                            "title", chapters[i].title);
1428            max_start = chapters[i].start;
1429        }
1430
1431    index_list = &matroska->index;
1432    index = index_list->elem;
1433    if (index_list->nb_elem
1434        && index[0].time > 100000000000000/matroska->time_scale) {
1435        av_log(matroska->ctx, AV_LOG_WARNING, "Working around broken index.\n");
1436        index_scale = matroska->time_scale;
1437    }
1438    for (i=0; i<index_list->nb_elem; i++) {
1439        EbmlList *pos_list = &index[i].pos;
1440        MatroskaIndexPos *pos = pos_list->elem;
1441        for (j=0; j<pos_list->nb_elem; j++) {
1442            MatroskaTrack *track = matroska_find_track_by_num(matroska,
1443                                                              pos[j].track);
1444            if (track && track->stream)
1445                av_add_index_entry(track->stream,
1446                                   pos[j].pos + matroska->segment_start,
1447                                   index[i].time/index_scale, 0, 0,
1448                                   AVINDEX_KEYFRAME);
1449        }
1450    }
1451
1452    matroska_convert_tags(s);
1453
1454    return 0;
1455}
1456
1457/*
1458 * Put one packet in an application-supplied AVPacket struct.
1459 * Returns 0 on success or -1 on failure.
1460 */
1461static int matroska_deliver_packet(MatroskaDemuxContext *matroska,
1462                                   AVPacket *pkt)
1463{
1464    if (matroska->num_packets > 0) {
1465        memcpy(pkt, matroska->packets[0], sizeof(AVPacket));
1466        av_free(matroska->packets[0]);
1467        if (matroska->num_packets > 1) {
1468            memmove(&matroska->packets[0], &matroska->packets[1],
1469                    (matroska->num_packets - 1) * sizeof(AVPacket *));
1470            matroska->packets =
1471                av_realloc(matroska->packets, (matroska->num_packets - 1) *
1472                           sizeof(AVPacket *));
1473        } else {
1474            av_freep(&matroska->packets);
1475        }
1476        matroska->num_packets--;
1477        return 0;
1478    }
1479
1480    return -1;
1481}
1482
1483/*
1484 * Free all packets in our internal queue.
1485 */
1486static void matroska_clear_queue(MatroskaDemuxContext *matroska)
1487{
1488    if (matroska->packets) {
1489        int n;
1490        for (n = 0; n < matroska->num_packets; n++) {
1491            av_free_packet(matroska->packets[n]);
1492            av_free(matroska->packets[n]);
1493        }
1494        av_freep(&matroska->packets);
1495        matroska->num_packets = 0;
1496    }
1497}
1498
1499static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
1500                                int size, int64_t pos, uint64_t cluster_time,
1501                                uint64_t duration, int is_keyframe,
1502                                int64_t cluster_pos)
1503{
1504    uint64_t timecode = AV_NOPTS_VALUE;
1505    MatroskaTrack *track;
1506    int res = 0;
1507    AVStream *st;
1508    AVPacket *pkt;
1509    int16_t block_time;
1510    uint32_t *lace_size = NULL;
1511    int n, flags, laces = 0;
1512    uint64_t num;
1513
1514    if ((n = matroska_ebmlnum_uint(matroska, data, size, &num)) < 0) {
1515        av_log(matroska->ctx, AV_LOG_ERROR, "EBML block data error\n");
1516        return res;
1517    }
1518    data += n;
1519    size -= n;
1520
1521    track = matroska_find_track_by_num(matroska, num);
1522    if (size <= 3 || !track || !track->stream) {
1523        av_log(matroska->ctx, AV_LOG_INFO,
1524               "Invalid stream %"PRIu64" or size %u\n", num, size);
1525        return res;
1526    }
1527    st = track->stream;
1528    if (st->discard >= AVDISCARD_ALL)
1529        return res;
1530    if (duration == AV_NOPTS_VALUE)
1531        duration = track->default_duration / matroska->time_scale;
1532
1533    block_time = AV_RB16(data);
1534    data += 2;
1535    flags = *data++;
1536    size -= 3;
1537    if (is_keyframe == -1)
1538        is_keyframe = flags & 0x80 ? PKT_FLAG_KEY : 0;
1539
1540    if (cluster_time != (uint64_t)-1
1541        && (block_time >= 0 || cluster_time >= -block_time)) {
1542        timecode = cluster_time + block_time;
1543        if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE
1544            && timecode < track->end_timecode)
1545            is_keyframe = 0;  /* overlapping subtitles are not key frame */
1546        if (is_keyframe)
1547            av_add_index_entry(st, cluster_pos, timecode, 0,0,AVINDEX_KEYFRAME);
1548        track->end_timecode = FFMAX(track->end_timecode, timecode+duration);
1549    }
1550
1551    if (matroska->skip_to_keyframe && track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
1552        if (!is_keyframe || timecode < matroska->skip_to_timecode)
1553            return res;
1554        matroska->skip_to_keyframe = 0;
1555    }
1556
1557    switch ((flags & 0x06) >> 1) {
1558        case 0x0: /* no lacing */
1559            laces = 1;
1560            lace_size = av_mallocz(sizeof(int));
1561            lace_size[0] = size;
1562            break;
1563
1564        case 0x1: /* Xiph lacing */
1565        case 0x2: /* fixed-size lacing */
1566        case 0x3: /* EBML lacing */
1567            assert(size>0); // size <=3 is checked before size-=3 above
1568            laces = (*data) + 1;
1569            data += 1;
1570            size -= 1;
1571            lace_size = av_mallocz(laces * sizeof(int));
1572
1573            switch ((flags & 0x06) >> 1) {
1574                case 0x1: /* Xiph lacing */ {
1575                    uint8_t temp;
1576                    uint32_t total = 0;
1577                    for (n = 0; res == 0 && n < laces - 1; n++) {
1578                        while (1) {
1579                            if (size == 0) {
1580                                res = -1;
1581                                break;
1582                            }
1583                            temp = *data;
1584                            lace_size[n] += temp;
1585                            data += 1;
1586                            size -= 1;
1587                            if (temp != 0xff)
1588                                break;
1589                        }
1590                        total += lace_size[n];
1591                    }
1592                    lace_size[n] = size - total;
1593                    break;
1594                }
1595
1596                case 0x2: /* fixed-size lacing */
1597                    for (n = 0; n < laces; n++)
1598                        lace_size[n] = size / laces;
1599                    break;
1600
1601                case 0x3: /* EBML lacing */ {
1602                    uint32_t total;
1603                    n = matroska_ebmlnum_uint(matroska, data, size, &num);
1604                    if (n < 0) {
1605                        av_log(matroska->ctx, AV_LOG_INFO,
1606                               "EBML block data error\n");
1607                        break;
1608                    }
1609                    data += n;
1610                    size -= n;
1611                    total = lace_size[0] = num;
1612                    for (n = 1; res == 0 && n < laces - 1; n++) {
1613                        int64_t snum;
1614                        int r;
1615                        r = matroska_ebmlnum_sint(matroska, data, size, &snum);
1616                        if (r < 0) {
1617                            av_log(matroska->ctx, AV_LOG_INFO,
1618                                   "EBML block data error\n");
1619                            break;
1620                        }
1621                        data += r;
1622                        size -= r;
1623                        lace_size[n] = lace_size[n - 1] + snum;
1624                        total += lace_size[n];
1625                    }
1626                    lace_size[n] = size - total;
1627                    break;
1628                }
1629            }
1630            break;
1631    }
1632
1633    if (res == 0) {
1634        for (n = 0; n < laces; n++) {
1635            if (st->codec->codec_id == CODEC_ID_RA_288 ||
1636                st->codec->codec_id == CODEC_ID_COOK ||
1637                st->codec->codec_id == CODEC_ID_ATRAC3) {
1638                int a = st->codec->block_align;
1639                int sps = track->audio.sub_packet_size;
1640                int cfs = track->audio.coded_framesize;
1641                int h = track->audio.sub_packet_h;
1642                int y = track->audio.sub_packet_cnt;
1643                int w = track->audio.frame_size;
1644                int x;
1645
1646                if (!track->audio.pkt_cnt) {
1647                    if (st->codec->codec_id == CODEC_ID_RA_288)
1648                        for (x=0; x<h/2; x++)
1649                            memcpy(track->audio.buf+x*2*w+y*cfs,
1650                                   data+x*cfs, cfs);
1651                    else
1652                        for (x=0; x<w/sps; x++)
1653                            memcpy(track->audio.buf+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), data+x*sps, sps);
1654
1655                    if (++track->audio.sub_packet_cnt >= h) {
1656                        track->audio.sub_packet_cnt = 0;
1657                        track->audio.pkt_cnt = h*w / a;
1658                    }
1659                }
1660                while (track->audio.pkt_cnt) {
1661                    pkt = av_mallocz(sizeof(AVPacket));
1662                    av_new_packet(pkt, a);
1663                    memcpy(pkt->data, track->audio.buf
1664                           + a * (h*w / a - track->audio.pkt_cnt--), a);
1665                    pkt->pos = pos;
1666                    pkt->stream_index = st->index;
1667                    dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
1668                }
1669            } else {
1670                MatroskaTrackEncoding *encodings = track->encodings.elem;
1671                int offset = 0, pkt_size = lace_size[n];
1672                uint8_t *pkt_data = data;
1673
1674                if (encodings && encodings->scope & 1) {
1675                    offset = matroska_decode_buffer(&pkt_data,&pkt_size, track);
1676                    if (offset < 0)
1677                        continue;
1678                }
1679
1680                pkt = av_mallocz(sizeof(AVPacket));
1681                /* XXX: prevent data copy... */
1682                if (av_new_packet(pkt, pkt_size+offset) < 0) {
1683                    av_free(pkt);
1684                    res = AVERROR(ENOMEM);
1685                    n = laces-1;
1686                    break;
1687                }
1688                if (offset)
1689                    memcpy (pkt->data, encodings->compression.settings.data, offset);
1690                memcpy (pkt->data+offset, pkt_data, pkt_size);
1691
1692                if (pkt_data != data)
1693                    av_free(pkt_data);
1694
1695                if (n == 0)
1696                    pkt->flags = is_keyframe;
1697                pkt->stream_index = st->index;
1698
1699                pkt->pts = timecode;
1700                pkt->pos = pos;
1701                if (st->codec->codec_id == CODEC_ID_TEXT)
1702                    pkt->convergence_duration = duration;
1703                else if (track->type != MATROSKA_TRACK_TYPE_SUBTITLE)
1704                    pkt->duration = duration;
1705
1706                if (st->codec->codec_id == CODEC_ID_SSA)
1707                    matroska_fix_ass_packet(matroska, pkt, duration);
1708
1709                if (matroska->prev_pkt &&
1710                    timecode != AV_NOPTS_VALUE &&
1711                    matroska->prev_pkt->pts == timecode &&
1712                    matroska->prev_pkt->stream_index == st->index)
1713                    matroska_merge_packets(matroska->prev_pkt, pkt);
1714                else {
1715                    dynarray_add(&matroska->packets,&matroska->num_packets,pkt);
1716                    matroska->prev_pkt = pkt;
1717                }
1718            }
1719
1720            if (timecode != AV_NOPTS_VALUE)
1721                timecode = duration ? timecode + duration : AV_NOPTS_VALUE;
1722            data += lace_size[n];
1723        }
1724    }
1725
1726    av_free(lace_size);
1727    return res;
1728}
1729
1730static int matroska_parse_cluster(MatroskaDemuxContext *matroska)
1731{
1732    MatroskaCluster cluster = { 0 };
1733    EbmlList *blocks_list;
1734    MatroskaBlock *blocks;
1735    int i, res;
1736    int64_t pos = url_ftell(matroska->ctx->pb);
1737    matroska->prev_pkt = NULL;
1738    if (matroska->has_cluster_id){
1739        /* For the first cluster we parse, its ID was already read as
1740           part of matroska_read_header(), so don't read it again */
1741        res = ebml_parse_id(matroska, matroska_clusters,
1742                            MATROSKA_ID_CLUSTER, &cluster);
1743        pos -= 4;  /* sizeof the ID which was already read */
1744        matroska->has_cluster_id = 0;
1745    } else
1746        res = ebml_parse(matroska, matroska_clusters, &cluster);
1747    blocks_list = &cluster.blocks;
1748    blocks = blocks_list->elem;
1749    for (i=0; i<blocks_list->nb_elem; i++)
1750        if (blocks[i].bin.size > 0)
1751            res=matroska_parse_block(matroska,
1752                                     blocks[i].bin.data, blocks[i].bin.size,
1753                                     blocks[i].bin.pos,  cluster.timecode,
1754                                     blocks[i].duration, !blocks[i].reference,
1755                                     pos);
1756    ebml_free(matroska_cluster, &cluster);
1757    if (res < 0)  matroska->done = 1;
1758    return res;
1759}
1760
1761static int matroska_read_packet(AVFormatContext *s, AVPacket *pkt)
1762{
1763    MatroskaDemuxContext *matroska = s->priv_data;
1764
1765    while (matroska_deliver_packet(matroska, pkt)) {
1766        if (matroska->done)
1767            return AVERROR_EOF;
1768        matroska_parse_cluster(matroska);
1769    }
1770
1771    return 0;
1772}
1773
1774static int matroska_read_seek(AVFormatContext *s, int stream_index,
1775                              int64_t timestamp, int flags)
1776{
1777    MatroskaDemuxContext *matroska = s->priv_data;
1778    MatroskaTrack *tracks = matroska->tracks.elem;
1779    AVStream *st = s->streams[stream_index];
1780    int i, index, index_sub, index_min;
1781
1782    if (!st->nb_index_entries)
1783        return 0;
1784    timestamp = FFMAX(timestamp, st->index_entries[0].timestamp);
1785
1786    if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
1787        url_fseek(s->pb, st->index_entries[st->nb_index_entries-1].pos, SEEK_SET);
1788        while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
1789            matroska_clear_queue(matroska);
1790            if (matroska_parse_cluster(matroska) < 0)
1791                break;
1792        }
1793    }
1794
1795    matroska_clear_queue(matroska);
1796    if (index < 0)
1797        return 0;
1798
1799    index_min = index;
1800    for (i=0; i < matroska->tracks.nb_elem; i++) {
1801        tracks[i].end_timecode = 0;
1802        if (tracks[i].type == MATROSKA_TRACK_TYPE_SUBTITLE
1803            && !tracks[i].stream->discard != AVDISCARD_ALL) {
1804            index_sub = av_index_search_timestamp(tracks[i].stream, st->index_entries[index].timestamp, AVSEEK_FLAG_BACKWARD);
1805            if (index_sub >= 0
1806                && st->index_entries[index_sub].pos < st->index_entries[index_min].pos
1807                && st->index_entries[index].timestamp - st->index_entries[index_sub].timestamp < 30000000000/matroska->time_scale)
1808                index_min = index_sub;
1809        }
1810    }
1811
1812    url_fseek(s->pb, st->index_entries[index_min].pos, SEEK_SET);
1813    matroska->skip_to_keyframe = !(flags & AVSEEK_FLAG_ANY);
1814    matroska->skip_to_timecode = st->index_entries[index].timestamp;
1815    matroska->done = 0;
1816    av_update_cur_dts(s, st, st->index_entries[index].timestamp);
1817    return 0;
1818}
1819
1820static int matroska_read_close(AVFormatContext *s)
1821{
1822    MatroskaDemuxContext *matroska = s->priv_data;
1823    MatroskaTrack *tracks = matroska->tracks.elem;
1824    int n;
1825
1826    matroska_clear_queue(matroska);
1827
1828    for (n=0; n < matroska->tracks.nb_elem; n++)
1829        if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)
1830            av_free(tracks[n].audio.buf);
1831    ebml_free(matroska_segment, matroska);
1832
1833    return 0;
1834}
1835
1836AVInputFormat matroska_demuxer = {
1837    "matroska",
1838    NULL_IF_CONFIG_SMALL("Matroska file format"),
1839    sizeof(MatroskaDemuxContext),
1840    matroska_probe,
1841    matroska_read_header,
1842    matroska_read_packet,
1843    matroska_read_close,
1844    matroska_read_seek,
1845    .metadata_conv = ff_mkv_metadata_conv,
1846};
1847