path: root/libavformat/matroskadec.c (plain)
blob: 3ec16365847a9498f47ed7f26feec62387d1db94

1	/*
2	* Matroska file demuxer
3	* Copyright (c) 2003-2008 The FFmpeg Project
4	*
5	* This file is part of FFmpeg.
6	*
7	* FFmpeg is free software; you can redistribute it and/or
8	* modify it under the terms of the GNU Lesser General Public
9	* License as published by the Free Software Foundation; either
10	* version 2.1 of the License, or (at your option) any later version.
11	*
12	* FFmpeg is distributed in the hope that it will be useful,
13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15	* Lesser General Public License for more details.
16	*
17	* You should have received a copy of the GNU Lesser General Public
18	* License along with FFmpeg; if not, write to the Free Software
19	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20	*/
21
22	/**
23	* @file
24	* Matroska file demuxer
25	* @author Ronald Bultje <rbultje@ronald.bitfreak.net>
26	* @author with a little help from Moritz Bunkus <moritz@bunkus.org>
27	* @author totally reworked by Aurelien Jacobs <aurel@gnuage.org>
28	* @see specs available on the Matroska project page: http://www.matroska.org/
29	*/
30
31	#include "config.h"
32
33	#include <inttypes.h>
34	#include <stdio.h>
35
36	#include "libavutil/avstring.h"
37	#include "libavutil/base64.h"
38	#include "libavutil/dict.h"
39	#include "libavutil/intfloat.h"
40	#include "libavutil/intreadwrite.h"
41	#include "libavutil/lzo.h"
42	#include "libavutil/mastering_display_metadata.h"
43	#include "libavutil/mathematics.h"
44	#include "libavutil/opt.h"
45	#include "libavutil/time_internal.h"
46	#include "libavutil/spherical.h"
47
48	#include "libavcodec/bytestream.h"
49	#include "libavcodec/flac.h"
50	#include "libavcodec/mpeg4audio.h"
51
52	#include "avformat.h"
53	#include "avio_internal.h"
54	#include "internal.h"
55	#include "isom.h"
56	#include "matroska.h"
57	#include "oggdec.h"
58	/* For ff_codec_get_id(). */
59	#include "riff.h"
60	#include "rmsipr.h"
61
62	#if CONFIG_BZLIB
63	#include <bzlib.h>
64	#endif
65	#if CONFIG_ZLIB
66	#include <zlib.h>
67	#endif
68
69	#include "qtpalette.h"
70
71	typedef enum {
72	EBML_NONE,
73	EBML_UINT,
74	EBML_FLOAT,
75	EBML_STR,
76	EBML_UTF8,
77	EBML_BIN,
78	EBML_NEST,
79	EBML_LEVEL1,
80	EBML_PASS,
81	EBML_STOP,
82	EBML_SINT,
83	EBML_TYPE_COUNT
84	} EbmlType;
85
86	typedef const struct EbmlSyntax {
87	uint32_t id;
88	EbmlType type;
89	int list_elem_size;
90	int data_offset;
91	union {
92	int64_t i;
93	uint64_t u;
94	double f;
95	const char *s;
96	const struct EbmlSyntax *n;
97	} def;
98	} EbmlSyntax;
99
100	typedef struct EbmlList {
101	int nb_elem;
102	void *elem;
103	} EbmlList;
104
105	typedef struct EbmlBin {
106	int size;
107	uint8_t *data;
108	int64_t pos;
109	} EbmlBin;
110
111	typedef struct Ebml {
112	uint64_t version;
113	uint64_t max_size;
114	uint64_t id_length;
115	char *doctype;
116	uint64_t doctype_version;
117	} Ebml;
118
119	typedef struct MatroskaTrackCompression {
120	uint64_t algo;
121	EbmlBin settings;
122	} MatroskaTrackCompression;
123
124	typedef struct MatroskaTrackEncryption {
125	uint64_t algo;
126	EbmlBin key_id;
127	} MatroskaTrackEncryption;
128
129	typedef struct MatroskaTrackEncoding {
130	uint64_t scope;
131	uint64_t type;
132	MatroskaTrackCompression compression;
133	MatroskaTrackEncryption encryption;
134	} MatroskaTrackEncoding;
135
136	typedef struct MatroskaMasteringMeta {
137	double r_x;
138	double r_y;
139	double g_x;
140	double g_y;
141	double b_x;
142	double b_y;
143	double white_x;
144	double white_y;
145	double max_luminance;
146	double min_luminance;
147	} MatroskaMasteringMeta;
148
149	typedef struct MatroskaTrackVideoColor {
150	uint64_t matrix_coefficients;
151	uint64_t bits_per_channel;
152	uint64_t chroma_sub_horz;
153	uint64_t chroma_sub_vert;
154	uint64_t cb_sub_horz;
155	uint64_t cb_sub_vert;
156	uint64_t chroma_siting_horz;
157	uint64_t chroma_siting_vert;
158	uint64_t range;
159	uint64_t transfer_characteristics;
160	uint64_t primaries;
161	uint64_t max_cll;
162	uint64_t max_fall;
163	MatroskaMasteringMeta mastering_meta;
164	} MatroskaTrackVideoColor;
165
166	typedef struct MatroskaTrackVideoProjection {
167	uint64_t type;
168	EbmlBin private;
169	double yaw;
170	double pitch;
171	double roll;
172	} MatroskaTrackVideoProjection;
173
174	typedef struct MatroskaTrackVideo {
175	double frame_rate;
176	uint64_t display_width;
177	uint64_t display_height;
178	uint64_t pixel_width;
179	uint64_t pixel_height;
180	EbmlBin color_space;
181	uint64_t display_unit;
182	uint64_t interlaced;
183	uint64_t field_order;
184	uint64_t stereo_mode;
185	uint64_t alpha_mode;
186	EbmlList color;
187	MatroskaTrackVideoProjection projection;
188	} MatroskaTrackVideo;
189
190	typedef struct MatroskaTrackAudio {
191	double samplerate;
192	double out_samplerate;
193	uint64_t bitdepth;
194	uint64_t channels;
195
196	/* real audio header (extracted from extradata) */
197	int coded_framesize;
198	int sub_packet_h;
199	int frame_size;
200	int sub_packet_size;
201	int sub_packet_cnt;
202	int pkt_cnt;
203	uint64_t buf_timecode;
204	uint8_t *buf;
205	} MatroskaTrackAudio;
206
207	typedef struct MatroskaTrackPlane {
208	uint64_t uid;
209	uint64_t type;
210	} MatroskaTrackPlane;
211
212	typedef struct MatroskaTrackOperation {
213	EbmlList combine_planes;
214	} MatroskaTrackOperation;
215
216	typedef struct MatroskaTrack {
217	uint64_t num;
218	uint64_t uid;
219	uint64_t type;
220	char *name;
221	char *codec_id;
222	EbmlBin codec_priv;
223	char *language;
224	double time_scale;
225	uint64_t default_duration;
226	uint64_t flag_default;
227	uint64_t flag_forced;
228	uint64_t seek_preroll;
229	MatroskaTrackVideo video;
230	MatroskaTrackAudio audio;
231	MatroskaTrackOperation operation;
232	EbmlList encodings;
233	uint64_t codec_delay;
234	uint64_t codec_delay_in_track_tb;
235
236	AVStream *stream;
237	int64_t end_timecode;
238	int ms_compat;
239	uint64_t max_block_additional_id;
240
241	uint32_t palette[AVPALETTE_COUNT];
242	int has_palette;
243	} MatroskaTrack;
244
245	typedef struct MatroskaAttachment {
246	uint64_t uid;
247	char *filename;
248	char *mime;
249	EbmlBin bin;
250
251	AVStream *stream;
252	} MatroskaAttachment;
253
254	typedef struct MatroskaChapter {
255	uint64_t start;
256	uint64_t end;
257	uint64_t uid;
258	char *title;
259
260	AVChapter *chapter;
261	} MatroskaChapter;
262
263	typedef struct MatroskaIndexPos {
264	uint64_t track;
265	uint64_t pos;
266	} MatroskaIndexPos;
267
268	typedef struct MatroskaIndex {
269	uint64_t time;
270	EbmlList pos;
271	} MatroskaIndex;
272
273	typedef struct MatroskaTag {
274	char *name;
275	char *string;
276	char *lang;
277	uint64_t def;
278	EbmlList sub;
279	} MatroskaTag;
280
281	typedef struct MatroskaTagTarget {
282	char *type;
283	uint64_t typevalue;
284	uint64_t trackuid;
285	uint64_t chapteruid;
286	uint64_t attachuid;
287	} MatroskaTagTarget;
288
289	typedef struct MatroskaTags {
290	MatroskaTagTarget target;
291	EbmlList tag;
292	} MatroskaTags;
293
294	typedef struct MatroskaSeekhead {
295	uint64_t id;
296	uint64_t pos;
297	} MatroskaSeekhead;
298
299	typedef struct MatroskaLevel {
300	uint64_t start;
301	uint64_t length;
302	} MatroskaLevel;
303
304	typedef struct MatroskaCluster {
305	uint64_t timecode;
306	EbmlList blocks;
307	} MatroskaCluster;
308
309	typedef struct MatroskaLevel1Element {
310	uint64_t id;
311	uint64_t pos;
312	int parsed;
313	} MatroskaLevel1Element;
314
315	typedef struct MatroskaDemuxContext {
316	const AVClass *class;
317	AVFormatContext *ctx;
318
319	/* EBML stuff */
320	int num_levels;
321	MatroskaLevel levels[EBML_MAX_DEPTH];
322	int level_up;
323	uint32_t current_id;
324
325	uint64_t time_scale;
326	double duration;
327	char *title;
328	char *muxingapp;
329	EbmlBin date_utc;
330	EbmlList tracks;
331	EbmlList attachments;
332	EbmlList chapters;
333	EbmlList index;
334	EbmlList tags;
335	EbmlList seekhead;
336
337	/* byte position of the segment inside the stream */
338	int64_t segment_start;
339
340	/* the packet queue */
341	AVPacket **packets;
342	int num_packets;
343	AVPacket *prev_pkt;
344
345	int done;
346
347	/* What to skip before effectively reading a packet. */
348	int skip_to_keyframe;
349	uint64_t skip_to_timecode;
350
351	/* File has a CUES element, but we defer parsing until it is needed. */
352	int cues_parsing_deferred;
353
354	/* Level1 elements and whether they were read yet */
355	MatroskaLevel1Element level1_elems[64];
356	int num_level1_elems;
357
358	int current_cluster_num_blocks;
359	int64_t current_cluster_pos;
360	MatroskaCluster current_cluster;
361
362	/* File has SSA subtitles which prevent incremental cluster parsing. */
363	int contains_ssa;
364
365	/* WebM DASH Manifest live flag/ */
366	int is_live;
367	} MatroskaDemuxContext;
368
369	typedef struct MatroskaBlock {
370	uint64_t duration;
371	int64_t reference;
372	uint64_t non_simple;
373	EbmlBin bin;
374	uint64_t additional_id;
375	EbmlBin additional;
376	int64_t discard_padding;
377	} MatroskaBlock;
378
379	static const EbmlSyntax ebml_header[] = {
380	{ EBML_ID_EBMLREADVERSION, EBML_UINT, 0, offsetof(Ebml, version), { .u = EBML_VERSION } },
381	{ EBML_ID_EBMLMAXSIZELENGTH, EBML_UINT, 0, offsetof(Ebml, max_size), { .u = 8 } },
382	{ EBML_ID_EBMLMAXIDLENGTH, EBML_UINT, 0, offsetof(Ebml, id_length), { .u = 4 } },
383	{ EBML_ID_DOCTYPE, EBML_STR, 0, offsetof(Ebml, doctype), { .s = "(none)" } },
384	{ EBML_ID_DOCTYPEREADVERSION, EBML_UINT, 0, offsetof(Ebml, doctype_version), { .u = 1 } },
385	{ EBML_ID_EBMLVERSION, EBML_NONE },
386	{ EBML_ID_DOCTYPEVERSION, EBML_NONE },
387	{ 0 }
388	};
389
390	static const EbmlSyntax ebml_syntax[] = {
391	{ EBML_ID_HEADER, EBML_NEST, 0, 0, { .n = ebml_header } },
392	{ 0 }
393	};
394
395	static const EbmlSyntax matroska_info[] = {
396	{ MATROSKA_ID_TIMECODESCALE, EBML_UINT, 0, offsetof(MatroskaDemuxContext, time_scale), { .u = 1000000 } },
397	{ MATROSKA_ID_DURATION, EBML_FLOAT, 0, offsetof(MatroskaDemuxContext, duration) },
398	{ MATROSKA_ID_TITLE, EBML_UTF8, 0, offsetof(MatroskaDemuxContext, title) },
399	{ MATROSKA_ID_WRITINGAPP, EBML_NONE },
400	{ MATROSKA_ID_MUXINGAPP, EBML_UTF8, 0, offsetof(MatroskaDemuxContext, muxingapp) },
401	{ MATROSKA_ID_DATEUTC, EBML_BIN, 0, offsetof(MatroskaDemuxContext, date_utc) },
402	{ MATROSKA_ID_SEGMENTUID, EBML_NONE },
403	{ 0 }
404	};
405
406	static const EbmlSyntax matroska_mastering_meta[] = {
407	{ MATROSKA_ID_VIDEOCOLOR_RX, EBML_FLOAT, 0, offsetof(MatroskaMasteringMeta, r_x), { .f=-1 } },
408	{ MATROSKA_ID_VIDEOCOLOR_RY, EBML_FLOAT, 0, offsetof(MatroskaMasteringMeta, r_y), { .f=-1 } },
409	{ MATROSKA_ID_VIDEOCOLOR_GX, EBML_FLOAT, 0, offsetof(MatroskaMasteringMeta, g_x), { .f=-1 } },
410	{ MATROSKA_ID_VIDEOCOLOR_GY, EBML_FLOAT, 0, offsetof(MatroskaMasteringMeta, g_y), { .f=-1 } },
411	{ MATROSKA_ID_VIDEOCOLOR_BX, EBML_FLOAT, 0, offsetof(MatroskaMasteringMeta, b_x), { .f=-1 } },
412	{ MATROSKA_ID_VIDEOCOLOR_BY, EBML_FLOAT, 0, offsetof(MatroskaMasteringMeta, b_y), { .f=-1 } },
413	{ MATROSKA_ID_VIDEOCOLOR_WHITEX, EBML_FLOAT, 0, offsetof(MatroskaMasteringMeta, white_x), { .f=-1 } },
414	{ MATROSKA_ID_VIDEOCOLOR_WHITEY, EBML_FLOAT, 0, offsetof(MatroskaMasteringMeta, white_y), { .f=-1 } },
415	{ MATROSKA_ID_VIDEOCOLOR_LUMINANCEMIN, EBML_FLOAT, 0, offsetof(MatroskaMasteringMeta, min_luminance), { .f=-1 } },
416	{ MATROSKA_ID_VIDEOCOLOR_LUMINANCEMAX, EBML_FLOAT, 0, offsetof(MatroskaMasteringMeta, max_luminance), { .f=-1 } },
417	{ 0 }
418	};
419
420	static const EbmlSyntax matroska_track_video_color[] = {
421	{ MATROSKA_ID_VIDEOCOLORMATRIXCOEFF, EBML_UINT, 0, offsetof(MatroskaTrackVideoColor, matrix_coefficients), { .u = AVCOL_SPC_UNSPECIFIED } },
422	{ MATROSKA_ID_VIDEOCOLORBITSPERCHANNEL, EBML_UINT, 0, offsetof(MatroskaTrackVideoColor, bits_per_channel), { .u=0 } },
423	{ MATROSKA_ID_VIDEOCOLORCHROMASUBHORZ, EBML_UINT, 0, offsetof(MatroskaTrackVideoColor, chroma_sub_horz), { .u=0 } },
424	{ MATROSKA_ID_VIDEOCOLORCHROMASUBVERT, EBML_UINT, 0, offsetof(MatroskaTrackVideoColor, chroma_sub_vert), { .u=0 } },
425	{ MATROSKA_ID_VIDEOCOLORCBSUBHORZ, EBML_UINT, 0, offsetof(MatroskaTrackVideoColor, cb_sub_horz), { .u=0 } },
426	{ MATROSKA_ID_VIDEOCOLORCBSUBVERT, EBML_UINT, 0, offsetof(MatroskaTrackVideoColor, cb_sub_vert), { .u=0 } },
427	{ MATROSKA_ID_VIDEOCOLORCHROMASITINGHORZ, EBML_UINT, 0, offsetof(MatroskaTrackVideoColor, chroma_siting_horz), { .u = MATROSKA_COLOUR_CHROMASITINGHORZ_UNDETERMINED } },
428	{ MATROSKA_ID_VIDEOCOLORCHROMASITINGVERT, EBML_UINT, 0, offsetof(MatroskaTrackVideoColor, chroma_siting_vert), { .u = MATROSKA_COLOUR_CHROMASITINGVERT_UNDETERMINED } },
429	{ MATROSKA_ID_VIDEOCOLORRANGE, EBML_UINT, 0, offsetof(MatroskaTrackVideoColor, range), { .u = AVCOL_RANGE_UNSPECIFIED } },
430	{ MATROSKA_ID_VIDEOCOLORTRANSFERCHARACTERISTICS, EBML_UINT, 0, offsetof(MatroskaTrackVideoColor, transfer_characteristics), { .u = AVCOL_TRC_UNSPECIFIED } },
431	{ MATROSKA_ID_VIDEOCOLORPRIMARIES, EBML_UINT, 0, offsetof(MatroskaTrackVideoColor, primaries), { .u = AVCOL_PRI_UNSPECIFIED } },
432	{ MATROSKA_ID_VIDEOCOLORMAXCLL, EBML_UINT, 0, offsetof(MatroskaTrackVideoColor, max_cll), { .u=0 } },
433	{ MATROSKA_ID_VIDEOCOLORMAXFALL, EBML_UINT, 0, offsetof(MatroskaTrackVideoColor, max_fall), { .u=0 } },
434	{ MATROSKA_ID_VIDEOCOLORMASTERINGMETA, EBML_NEST, 0, offsetof(MatroskaTrackVideoColor, mastering_meta), { .n = matroska_mastering_meta } },
435	{ 0 }
436	};
437
438	static const EbmlSyntax matroska_track_video_projection[] = {
439	{ MATROSKA_ID_VIDEOPROJECTIONTYPE, EBML_UINT, 0, offsetof(MatroskaTrackVideoProjection, type), { .u = MATROSKA_VIDEO_PROJECTION_TYPE_RECTANGULAR } },
440	{ MATROSKA_ID_VIDEOPROJECTIONPRIVATE, EBML_BIN, 0, offsetof(MatroskaTrackVideoProjection, private) },
441	{ MATROSKA_ID_VIDEOPROJECTIONPOSEYAW, EBML_FLOAT, 0, offsetof(MatroskaTrackVideoProjection, yaw), { .f=0.0 } },
442	{ MATROSKA_ID_VIDEOPROJECTIONPOSEPITCH, EBML_FLOAT, 0, offsetof(MatroskaTrackVideoProjection, pitch), { .f=0.0 } },
443	{ MATROSKA_ID_VIDEOPROJECTIONPOSEROLL, EBML_FLOAT, 0, offsetof(MatroskaTrackVideoProjection, roll), { .f=0.0 } },
444	{ 0 }
445	};
446
447	static const EbmlSyntax matroska_track_video[] = {
448	{ MATROSKA_ID_VIDEOFRAMERATE, EBML_FLOAT, 0, offsetof(MatroskaTrackVideo, frame_rate) },
449	{ MATROSKA_ID_VIDEODISPLAYWIDTH, EBML_UINT, 0, offsetof(MatroskaTrackVideo, display_width), { .u=-1 } },
450	{ MATROSKA_ID_VIDEODISPLAYHEIGHT, EBML_UINT, 0, offsetof(MatroskaTrackVideo, display_height), { .u=-1 } },
451	{ MATROSKA_ID_VIDEOPIXELWIDTH, EBML_UINT, 0, offsetof(MatroskaTrackVideo, pixel_width) },
452	{ MATROSKA_ID_VIDEOPIXELHEIGHT, EBML_UINT, 0, offsetof(MatroskaTrackVideo, pixel_height) },
453	{ MATROSKA_ID_VIDEOCOLORSPACE, EBML_BIN, 0, offsetof(MatroskaTrackVideo, color_space) },
454	{ MATROSKA_ID_VIDEOALPHAMODE, EBML_UINT, 0, offsetof(MatroskaTrackVideo, alpha_mode) },
455	{ MATROSKA_ID_VIDEOCOLOR, EBML_NEST, sizeof(MatroskaTrackVideoColor), offsetof(MatroskaTrackVideo, color), { .n = matroska_track_video_color } },
456	{ MATROSKA_ID_VIDEOPROJECTION, EBML_NEST, 0, offsetof(MatroskaTrackVideo, projection), { .n = matroska_track_video_projection } },
457	{ MATROSKA_ID_VIDEOPIXELCROPB, EBML_NONE },
458	{ MATROSKA_ID_VIDEOPIXELCROPT, EBML_NONE },
459	{ MATROSKA_ID_VIDEOPIXELCROPL, EBML_NONE },
460	{ MATROSKA_ID_VIDEOPIXELCROPR, EBML_NONE },
461	{ MATROSKA_ID_VIDEODISPLAYUNIT, EBML_UINT, 0, offsetof(MatroskaTrackVideo, display_unit), { .u= MATROSKA_VIDEO_DISPLAYUNIT_PIXELS } },
462	{ MATROSKA_ID_VIDEOFLAGINTERLACED, EBML_UINT, 0, offsetof(MatroskaTrackVideo, interlaced), { .u = MATROSKA_VIDEO_INTERLACE_FLAG_UNDETERMINED } },
463	{ MATROSKA_ID_VIDEOFIELDORDER, EBML_UINT, 0, offsetof(MatroskaTrackVideo, field_order), { .u = MATROSKA_VIDEO_FIELDORDER_UNDETERMINED } },
464	{ MATROSKA_ID_VIDEOSTEREOMODE, EBML_UINT, 0, offsetof(MatroskaTrackVideo, stereo_mode), { .u = MATROSKA_VIDEO_STEREOMODE_TYPE_NB } },
465	{ MATROSKA_ID_VIDEOASPECTRATIO, EBML_NONE },
466	{ 0 }
467	};
468
469	static const EbmlSyntax matroska_track_audio[] = {
470	{ MATROSKA_ID_AUDIOSAMPLINGFREQ, EBML_FLOAT, 0, offsetof(MatroskaTrackAudio, samplerate), { .f = 8000.0 } },
471	{ MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, EBML_FLOAT, 0, offsetof(MatroskaTrackAudio, out_samplerate) },
472	{ MATROSKA_ID_AUDIOBITDEPTH, EBML_UINT, 0, offsetof(MatroskaTrackAudio, bitdepth) },
473	{ MATROSKA_ID_AUDIOCHANNELS, EBML_UINT, 0, offsetof(MatroskaTrackAudio, channels), { .u = 1 } },
474	{ 0 }
475	};
476
477	static const EbmlSyntax matroska_track_encoding_compression[] = {
478	{ MATROSKA_ID_ENCODINGCOMPALGO, EBML_UINT, 0, offsetof(MatroskaTrackCompression, algo), { .u = 0 } },
479	{ MATROSKA_ID_ENCODINGCOMPSETTINGS, EBML_BIN, 0, offsetof(MatroskaTrackCompression, settings) },
480	{ 0 }
481	};
482
483	static const EbmlSyntax matroska_track_encoding_encryption[] = {
484	{ MATROSKA_ID_ENCODINGENCALGO, EBML_UINT, 0, offsetof(MatroskaTrackEncryption,algo), {.u = 0} },
485	{ MATROSKA_ID_ENCODINGENCKEYID, EBML_BIN, 0, offsetof(MatroskaTrackEncryption,key_id) },
486	{ MATROSKA_ID_ENCODINGENCAESSETTINGS, EBML_NONE },
487	{ MATROSKA_ID_ENCODINGSIGALGO, EBML_NONE },
488	{ MATROSKA_ID_ENCODINGSIGHASHALGO, EBML_NONE },
489	{ MATROSKA_ID_ENCODINGSIGKEYID, EBML_NONE },
490	{ MATROSKA_ID_ENCODINGSIGNATURE, EBML_NONE },
491	{ 0 }
492	};
493	static const EbmlSyntax matroska_track_encoding[] = {
494	{ MATROSKA_ID_ENCODINGSCOPE, EBML_UINT, 0, offsetof(MatroskaTrackEncoding, scope), { .u = 1 } },
495	{ MATROSKA_ID_ENCODINGTYPE, EBML_UINT, 0, offsetof(MatroskaTrackEncoding, type), { .u = 0 } },
496	{ MATROSKA_ID_ENCODINGCOMPRESSION, EBML_NEST, 0, offsetof(MatroskaTrackEncoding, compression), { .n = matroska_track_encoding_compression } },
497	{ MATROSKA_ID_ENCODINGENCRYPTION, EBML_NEST, 0, offsetof(MatroskaTrackEncoding, encryption), { .n = matroska_track_encoding_encryption } },
498	{ MATROSKA_ID_ENCODINGORDER, EBML_NONE },
499	{ 0 }
500	};
501
502	static const EbmlSyntax matroska_track_encodings[] = {
503	{ MATROSKA_ID_TRACKCONTENTENCODING, EBML_NEST, sizeof(MatroskaTrackEncoding), offsetof(MatroskaTrack, encodings), { .n = matroska_track_encoding } },
504	{ 0 }
505	};
506
507	static const EbmlSyntax matroska_track_plane[] = {
508	{ MATROSKA_ID_TRACKPLANEUID, EBML_UINT, 0, offsetof(MatroskaTrackPlane,uid) },
509	{ MATROSKA_ID_TRACKPLANETYPE, EBML_UINT, 0, offsetof(MatroskaTrackPlane,type) },
510	{ 0 }
511	};
512
513	static const EbmlSyntax matroska_track_combine_planes[] = {
514	{ MATROSKA_ID_TRACKPLANE, EBML_NEST, sizeof(MatroskaTrackPlane), offsetof(MatroskaTrackOperation,combine_planes), {.n = matroska_track_plane} },
515	{ 0 }
516	};
517
518	static const EbmlSyntax matroska_track_operation[] = {
519	{ MATROSKA_ID_TRACKCOMBINEPLANES, EBML_NEST, 0, 0, {.n = matroska_track_combine_planes} },
520	{ 0 }
521	};
522
523	static const EbmlSyntax matroska_track[] = {
524	{ MATROSKA_ID_TRACKNUMBER, EBML_UINT, 0, offsetof(MatroskaTrack, num) },
525	{ MATROSKA_ID_TRACKNAME, EBML_UTF8, 0, offsetof(MatroskaTrack, name) },
526	{ MATROSKA_ID_TRACKUID, EBML_UINT, 0, offsetof(MatroskaTrack, uid) },
527	{ MATROSKA_ID_TRACKTYPE, EBML_UINT, 0, offsetof(MatroskaTrack, type) },
528	{ MATROSKA_ID_CODECID, EBML_STR, 0, offsetof(MatroskaTrack, codec_id) },
529	{ MATROSKA_ID_CODECPRIVATE, EBML_BIN, 0, offsetof(MatroskaTrack, codec_priv) },
530	{ MATROSKA_ID_CODECDELAY, EBML_UINT, 0, offsetof(MatroskaTrack, codec_delay) },
531	{ MATROSKA_ID_TRACKLANGUAGE, EBML_UTF8, 0, offsetof(MatroskaTrack, language), { .s = "eng" } },
532	{ MATROSKA_ID_TRACKDEFAULTDURATION, EBML_UINT, 0, offsetof(MatroskaTrack, default_duration) },
533	{ MATROSKA_ID_TRACKTIMECODESCALE, EBML_FLOAT, 0, offsetof(MatroskaTrack, time_scale), { .f = 1.0 } },
534	{ MATROSKA_ID_TRACKFLAGDEFAULT, EBML_UINT, 0, offsetof(MatroskaTrack, flag_default), { .u = 1 } },
535	{ MATROSKA_ID_TRACKFLAGFORCED, EBML_UINT, 0, offsetof(MatroskaTrack, flag_forced), { .u = 0 } },
536	{ MATROSKA_ID_TRACKVIDEO, EBML_NEST, 0, offsetof(MatroskaTrack, video), { .n = matroska_track_video } },
537	{ MATROSKA_ID_TRACKAUDIO, EBML_NEST, 0, offsetof(MatroskaTrack, audio), { .n = matroska_track_audio } },
538	{ MATROSKA_ID_TRACKOPERATION, EBML_NEST, 0, offsetof(MatroskaTrack, operation), { .n = matroska_track_operation } },
539	{ MATROSKA_ID_TRACKCONTENTENCODINGS, EBML_NEST, 0, 0, { .n = matroska_track_encodings } },
540	{ MATROSKA_ID_TRACKMAXBLKADDID, EBML_UINT, 0, offsetof(MatroskaTrack, max_block_additional_id) },
541	{ MATROSKA_ID_SEEKPREROLL, EBML_UINT, 0, offsetof(MatroskaTrack, seek_preroll) },
542	{ MATROSKA_ID_TRACKFLAGENABLED, EBML_NONE },
543	{ MATROSKA_ID_TRACKFLAGLACING, EBML_NONE },
544	{ MATROSKA_ID_CODECNAME, EBML_NONE },
545	{ MATROSKA_ID_CODECDECODEALL, EBML_NONE },
546	{ MATROSKA_ID_CODECINFOURL, EBML_NONE },
547	{ MATROSKA_ID_CODECDOWNLOADURL, EBML_NONE },
548	{ MATROSKA_ID_TRACKMINCACHE, EBML_NONE },
549	{ MATROSKA_ID_TRACKMAXCACHE, EBML_NONE },
550	{ 0 }
551	};
552
553	static const EbmlSyntax matroska_tracks[] = {
554	{ MATROSKA_ID_TRACKENTRY, EBML_NEST, sizeof(MatroskaTrack), offsetof(MatroskaDemuxContext, tracks), { .n = matroska_track } },
555	{ 0 }
556	};
557
558	static const EbmlSyntax matroska_attachment[] = {
559	{ MATROSKA_ID_FILEUID, EBML_UINT, 0, offsetof(MatroskaAttachment, uid) },
560	{ MATROSKA_ID_FILENAME, EBML_UTF8, 0, offsetof(MatroskaAttachment, filename) },
561	{ MATROSKA_ID_FILEMIMETYPE, EBML_STR, 0, offsetof(MatroskaAttachment, mime) },
562	{ MATROSKA_ID_FILEDATA, EBML_BIN, 0, offsetof(MatroskaAttachment, bin) },
563	{ MATROSKA_ID_FILEDESC, EBML_NONE },
564	{ 0 }
565	};
566
567	static const EbmlSyntax matroska_attachments[] = {
568	{ MATROSKA_ID_ATTACHEDFILE, EBML_NEST, sizeof(MatroskaAttachment), offsetof(MatroskaDemuxContext, attachments), { .n = matroska_attachment } },
569	{ 0 }
570	};
571
572	static const EbmlSyntax matroska_chapter_display[] = {
573	{ MATROSKA_ID_CHAPSTRING, EBML_UTF8, 0, offsetof(MatroskaChapter, title) },
574	{ MATROSKA_ID_CHAPLANG, EBML_NONE },
575	{ MATROSKA_ID_CHAPCOUNTRY, EBML_NONE },
576	{ 0 }
577	};
578
579	static const EbmlSyntax matroska_chapter_entry[] = {
580	{ MATROSKA_ID_CHAPTERTIMESTART, EBML_UINT, 0, offsetof(MatroskaChapter, start), { .u = AV_NOPTS_VALUE } },
581	{ MATROSKA_ID_CHAPTERTIMEEND, EBML_UINT, 0, offsetof(MatroskaChapter, end), { .u = AV_NOPTS_VALUE } },
582	{ MATROSKA_ID_CHAPTERUID, EBML_UINT, 0, offsetof(MatroskaChapter, uid) },
583	{ MATROSKA_ID_CHAPTERDISPLAY, EBML_NEST, 0, 0, { .n = matroska_chapter_display } },
584	{ MATROSKA_ID_CHAPTERFLAGHIDDEN, EBML_NONE },
585	{ MATROSKA_ID_CHAPTERFLAGENABLED, EBML_NONE },
586	{ MATROSKA_ID_CHAPTERPHYSEQUIV, EBML_NONE },
587	{ MATROSKA_ID_CHAPTERATOM, EBML_NONE },
588	{ 0 }
589	};
590
591	static const EbmlSyntax matroska_chapter[] = {
592	{ MATROSKA_ID_CHAPTERATOM, EBML_NEST, sizeof(MatroskaChapter), offsetof(MatroskaDemuxContext, chapters), { .n = matroska_chapter_entry } },
593	{ MATROSKA_ID_EDITIONUID, EBML_NONE },
594	{ MATROSKA_ID_EDITIONFLAGHIDDEN, EBML_NONE },
595	{ MATROSKA_ID_EDITIONFLAGDEFAULT, EBML_NONE },
596	{ MATROSKA_ID_EDITIONFLAGORDERED, EBML_NONE },
597	{ 0 }
598	};
599
600	static const EbmlSyntax matroska_chapters[] = {
601	{ MATROSKA_ID_EDITIONENTRY, EBML_NEST, 0, 0, { .n = matroska_chapter } },
602	{ 0 }
603	};
604
605	static const EbmlSyntax matroska_index_pos[] = {
606	{ MATROSKA_ID_CUETRACK, EBML_UINT, 0, offsetof(MatroskaIndexPos, track) },
607	{ MATROSKA_ID_CUECLUSTERPOSITION, EBML_UINT, 0, offsetof(MatroskaIndexPos, pos) },
608	{ MATROSKA_ID_CUERELATIVEPOSITION,EBML_NONE },
609	{ MATROSKA_ID_CUEDURATION, EBML_NONE },
610	{ MATROSKA_ID_CUEBLOCKNUMBER, EBML_NONE },
611	{ 0 }
612	};
613
614	static const EbmlSyntax matroska_index_entry[] = {
615	{ MATROSKA_ID_CUETIME, EBML_UINT, 0, offsetof(MatroskaIndex, time) },
616	{ MATROSKA_ID_CUETRACKPOSITION, EBML_NEST, sizeof(MatroskaIndexPos), offsetof(MatroskaIndex, pos), { .n = matroska_index_pos } },
617	{ 0 }
618	};
619
620	static const EbmlSyntax matroska_index[] = {
621	{ MATROSKA_ID_POINTENTRY, EBML_NEST, sizeof(MatroskaIndex), offsetof(MatroskaDemuxContext, index), { .n = matroska_index_entry } },
622	{ 0 }
623	};
624
625	static const EbmlSyntax matroska_simpletag[] = {
626	{ MATROSKA_ID_TAGNAME, EBML_UTF8, 0, offsetof(MatroskaTag, name) },
627	{ MATROSKA_ID_TAGSTRING, EBML_UTF8, 0, offsetof(MatroskaTag, string) },
628	{ MATROSKA_ID_TAGLANG, EBML_STR, 0, offsetof(MatroskaTag, lang), { .s = "und" } },
629	{ MATROSKA_ID_TAGDEFAULT, EBML_UINT, 0, offsetof(MatroskaTag, def) },
630	{ MATROSKA_ID_TAGDEFAULT_BUG, EBML_UINT, 0, offsetof(MatroskaTag, def) },
631	{ MATROSKA_ID_SIMPLETAG, EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTag, sub), { .n = matroska_simpletag } },
632	{ 0 }
633	};
634
635	static const EbmlSyntax matroska_tagtargets[] = {
636	{ MATROSKA_ID_TAGTARGETS_TYPE, EBML_STR, 0, offsetof(MatroskaTagTarget, type) },
637	{ MATROSKA_ID_TAGTARGETS_TYPEVALUE, EBML_UINT, 0, offsetof(MatroskaTagTarget, typevalue), { .u = 50 } },
638	{ MATROSKA_ID_TAGTARGETS_TRACKUID, EBML_UINT, 0, offsetof(MatroskaTagTarget, trackuid) },
639	{ MATROSKA_ID_TAGTARGETS_CHAPTERUID, EBML_UINT, 0, offsetof(MatroskaTagTarget, chapteruid) },
640	{ MATROSKA_ID_TAGTARGETS_ATTACHUID, EBML_UINT, 0, offsetof(MatroskaTagTarget, attachuid) },
641	{ 0 }
642	};
643
644	static const EbmlSyntax matroska_tag[] = {
645	{ MATROSKA_ID_SIMPLETAG, EBML_NEST, sizeof(MatroskaTag), offsetof(MatroskaTags, tag), { .n = matroska_simpletag } },
646	{ MATROSKA_ID_TAGTARGETS, EBML_NEST, 0, offsetof(MatroskaTags, target), { .n = matroska_tagtargets } },
647	{ 0 }
648	};
649
650	static const EbmlSyntax matroska_tags[] = {
651	{ MATROSKA_ID_TAG, EBML_NEST, sizeof(MatroskaTags), offsetof(MatroskaDemuxContext, tags), { .n = matroska_tag } },
652	{ 0 }
653	};
654
655	static const EbmlSyntax matroska_seekhead_entry[] = {
656	{ MATROSKA_ID_SEEKID, EBML_UINT, 0, offsetof(MatroskaSeekhead, id) },
657	{ MATROSKA_ID_SEEKPOSITION, EBML_UINT, 0, offsetof(MatroskaSeekhead, pos), { .u = -1 } },
658	{ 0 }
659	};
660
661	static const EbmlSyntax matroska_seekhead[] = {
662	{ MATROSKA_ID_SEEKENTRY, EBML_NEST, sizeof(MatroskaSeekhead), offsetof(MatroskaDemuxContext, seekhead), { .n = matroska_seekhead_entry } },
663	{ 0 }
664	};
665
666	static const EbmlSyntax matroska_segment[] = {
667	{ MATROSKA_ID_INFO, EBML_LEVEL1, 0, 0, { .n = matroska_info } },
668	{ MATROSKA_ID_TRACKS, EBML_LEVEL1, 0, 0, { .n = matroska_tracks } },
669	{ MATROSKA_ID_ATTACHMENTS, EBML_LEVEL1, 0, 0, { .n = matroska_attachments } },
670	{ MATROSKA_ID_CHAPTERS, EBML_LEVEL1, 0, 0, { .n = matroska_chapters } },
671	{ MATROSKA_ID_CUES, EBML_LEVEL1, 0, 0, { .n = matroska_index } },
672	{ MATROSKA_ID_TAGS, EBML_LEVEL1, 0, 0, { .n = matroska_tags } },
673	{ MATROSKA_ID_SEEKHEAD, EBML_LEVEL1, 0, 0, { .n = matroska_seekhead } },
674	{ MATROSKA_ID_CLUSTER, EBML_STOP },
675	{ 0 }
676	};
677
678	static const EbmlSyntax matroska_segments[] = {
679	{ MATROSKA_ID_SEGMENT, EBML_NEST, 0, 0, { .n = matroska_segment } },
680	{ 0 }
681	};
682
683	static const EbmlSyntax matroska_blockmore[] = {
684	{ MATROSKA_ID_BLOCKADDID, EBML_UINT, 0, offsetof(MatroskaBlock,additional_id) },
685	{ MATROSKA_ID_BLOCKADDITIONAL, EBML_BIN, 0, offsetof(MatroskaBlock,additional) },
686	{ 0 }
687	};
688
689	static const EbmlSyntax matroska_blockadditions[] = {
690	{ MATROSKA_ID_BLOCKMORE, EBML_NEST, 0, 0, {.n = matroska_blockmore} },
691	{ 0 }
692	};
693
694	static const EbmlSyntax matroska_blockgroup[] = {
695	{ MATROSKA_ID_BLOCK, EBML_BIN, 0, offsetof(MatroskaBlock, bin) },
696	{ MATROSKA_ID_BLOCKADDITIONS, EBML_NEST, 0, 0, { .n = matroska_blockadditions} },
697	{ MATROSKA_ID_SIMPLEBLOCK, EBML_BIN, 0, offsetof(MatroskaBlock, bin) },
698	{ MATROSKA_ID_BLOCKDURATION, EBML_UINT, 0, offsetof(MatroskaBlock, duration) },
699	{ MATROSKA_ID_DISCARDPADDING, EBML_SINT, 0, offsetof(MatroskaBlock, discard_padding) },
700	{ MATROSKA_ID_BLOCKREFERENCE, EBML_SINT, 0, offsetof(MatroskaBlock, reference), { .i = INT64_MIN } },
701	{ MATROSKA_ID_CODECSTATE, EBML_NONE },
702	{ 1, EBML_UINT, 0, offsetof(MatroskaBlock, non_simple), { .u = 1 } },
703	{ 0 }
704	};
705
706	static const EbmlSyntax matroska_cluster[] = {
707	{ MATROSKA_ID_CLUSTERTIMECODE, EBML_UINT, 0, offsetof(MatroskaCluster, timecode) },
708	{ MATROSKA_ID_BLOCKGROUP, EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster, blocks), { .n = matroska_blockgroup } },
709	{ MATROSKA_ID_SIMPLEBLOCK, EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster, blocks), { .n = matroska_blockgroup } },
710	{ MATROSKA_ID_CLUSTERPOSITION, EBML_NONE },
711	{ MATROSKA_ID_CLUSTERPREVSIZE, EBML_NONE },
712	{ 0 }
713	};
714
715	static const EbmlSyntax matroska_clusters[] = {
716	{ MATROSKA_ID_CLUSTER, EBML_NEST, 0, 0, { .n = matroska_cluster } },
717	{ MATROSKA_ID_INFO, EBML_NONE },
718	{ MATROSKA_ID_CUES, EBML_NONE },
719	{ MATROSKA_ID_TAGS, EBML_NONE },
720	{ MATROSKA_ID_SEEKHEAD, EBML_NONE },
721	{ 0 }
722	};
723
724	static const EbmlSyntax matroska_cluster_incremental_parsing[] = {
725	{ MATROSKA_ID_CLUSTERTIMECODE, EBML_UINT, 0, offsetof(MatroskaCluster, timecode) },
726	{ MATROSKA_ID_BLOCKGROUP, EBML_NEST, sizeof(MatroskaBlock), offsetof(MatroskaCluster, blocks), { .n = matroska_blockgroup } },
727	{ MATROSKA_ID_SIMPLEBLOCK, EBML_PASS, sizeof(MatroskaBlock), offsetof(MatroskaCluster, blocks), { .n = matroska_blockgroup } },
728	{ MATROSKA_ID_CLUSTERPOSITION, EBML_NONE },
729	{ MATROSKA_ID_CLUSTERPREVSIZE, EBML_NONE },
730	{ MATROSKA_ID_INFO, EBML_NONE },
731	{ MATROSKA_ID_CUES, EBML_NONE },
732	{ MATROSKA_ID_TAGS, EBML_NONE },
733	{ MATROSKA_ID_SEEKHEAD, EBML_NONE },
734	{ MATROSKA_ID_CLUSTER, EBML_STOP },
735	{ 0 }
736	};
737
738	static const EbmlSyntax matroska_cluster_incremental[] = {
739	{ MATROSKA_ID_CLUSTERTIMECODE, EBML_UINT, 0, offsetof(MatroskaCluster, timecode) },
740	{ MATROSKA_ID_BLOCKGROUP, EBML_STOP },
741	{ MATROSKA_ID_SIMPLEBLOCK, EBML_STOP },
742	{ MATROSKA_ID_CLUSTERPOSITION, EBML_NONE },
743	{ MATROSKA_ID_CLUSTERPREVSIZE, EBML_NONE },
744	{ 0 }
745	};
746
747	static const EbmlSyntax matroska_clusters_incremental[] = {
748	{ MATROSKA_ID_CLUSTER, EBML_NEST, 0, 0, { .n = matroska_cluster_incremental } },
749	{ MATROSKA_ID_INFO, EBML_NONE },
750	{ MATROSKA_ID_CUES, EBML_NONE },
751	{ MATROSKA_ID_TAGS, EBML_NONE },
752	{ MATROSKA_ID_SEEKHEAD, EBML_NONE },
753	{ 0 }
754	};
755
756	static const char *const matroska_doctypes[] = { "matroska", "webm" };
757
758	static int matroska_read_close(AVFormatContext *s);
759
760	static int matroska_resync(MatroskaDemuxContext *matroska, int64_t last_pos)
761	{
762	AVIOContext *pb = matroska->ctx->pb;
763	int64_t ret;
764	uint32_t id;
765	matroska->current_id = 0;
766	matroska->num_levels = 0;
767
768	/* seek to next position to resync from */
769	if ((ret = avio_seek(pb, last_pos + 1, SEEK_SET)) < 0) {
770	matroska->done = 1;
771	return ret;
772	}
773
774	id = avio_rb32(pb);
775
776	// try to find a toplevel element
777	while (!avio_feof(pb)) {
778	if (id == MATROSKA_ID_INFO || id == MATROSKA_ID_TRACKS ||
779	id == MATROSKA_ID_CUES || id == MATROSKA_ID_TAGS ||
780	id == MATROSKA_ID_SEEKHEAD || id == MATROSKA_ID_ATTACHMENTS ||
781	id == MATROSKA_ID_CLUSTER || id == MATROSKA_ID_CHAPTERS) {
782	matroska->current_id = id;
783	return 0;
784	}
785	id = (id << 8) | avio_r8(pb);
786	}
787
788	matroska->done = 1;
789	return AVERROR_EOF;
790	}
791
792	/*
793	* Return: Whether we reached the end of a level in the hierarchy or not.
794	*/
795	static int ebml_level_end(MatroskaDemuxContext *matroska)
796	{
797	AVIOContext *pb = matroska->ctx->pb;
798	int64_t pos = avio_tell(pb);
799
800	if (matroska->num_levels > 0) {
801	MatroskaLevel *level = &matroska->levels[matroska->num_levels - 1];
802	if (pos - level->start >= level->length || matroska->current_id) {
803	matroska->num_levels--;
804	return 1;
805	}
806	}
807	return (matroska->is_live && matroska->ctx->pb->eof_reached) ? 1 : 0;
808	}
809
810	/*
811	* Read: an "EBML number", which is defined as a variable-length
812	* array of bytes. The first byte indicates the length by giving a
813	* number of 0-bits followed by a one. The position of the first
814	* "one" bit inside the first byte indicates the length of this
815	* number.
816	* Returns: number of bytes read, < 0 on error
817	*/
818	static int ebml_read_num(MatroskaDemuxContext *matroska, AVIOContext *pb,
819	int max_size, uint64_t *number)
820	{
821	int read = 1, n = 1;
822	uint64_t total = 0;
823
824	/* The first byte tells us the length in bytes - avio_r8() can normally
825	* return 0, but since that's not a valid first ebmlID byte, we can
826	* use it safely here to catch EOS. */
827	if (!(total = avio_r8(pb))) {
828	/* we might encounter EOS here */
829	if (!avio_feof(pb)) {
830	int64_t pos = avio_tell(pb);
831	av_log(matroska->ctx, AV_LOG_ERROR,
832	"Read error at pos. %"PRIu64" (0x%"PRIx64")\n",
833	pos, pos);
834	return pb->error ? pb->error : AVERROR(EIO);
835	}
836	return AVERROR_EOF;
837	}
838
839	/* get the length of the EBML number */
840	read = 8 - ff_log2_tab[total];
841	if (read > max_size) {
842	int64_t pos = avio_tell(pb) - 1;
843	av_log(matroska->ctx, AV_LOG_ERROR,
844	"Invalid EBML number size tag 0x%02x at pos %"PRIu64" (0x%"PRIx64")\n",
845	(uint8_t) total, pos, pos);
846	return AVERROR_INVALIDDATA;
847	}
848
849	/* read out length */
850	total ^= 1 << ff_log2_tab[total];
851	while (n++ < read)
852	total = (total << 8) | avio_r8(pb);
853
854	*number = total;
855
856	return read;
857	}
858
859	/**
860	* Read a EBML length value.
861	* This needs special handling for the "unknown length" case which has multiple
862	* encodings.
863	*/
864	static int ebml_read_length(MatroskaDemuxContext *matroska, AVIOContext *pb,
865	uint64_t *number)
866	{
867	int res = ebml_read_num(matroska, pb, 8, number);
868	if (res > 0 && *number + 1 == 1ULL << (7 * res))
869	*number = 0xffffffffffffffULL;
870	return res;
871	}
872
873	/*
874	* Read the next element as an unsigned int.
875	* 0 is success, < 0 is failure.
876	*/
877	static int ebml_read_uint(AVIOContext *pb, int size, uint64_t *num)
878	{
879	int n = 0;
880
881	if (size > 8)
882	return AVERROR_INVALIDDATA;
883
884	/* big-endian ordering; build up number */
885	*num = 0;
886	while (n++ < size)
887	*num = (*num << 8) | avio_r8(pb);
888
889	return 0;
890	}
891
892	/*
893	* Read the next element as a signed int.
894	* 0 is success, < 0 is failure.
895	*/
896	static int ebml_read_sint(AVIOContext *pb, int size, int64_t *num)
897	{
898	int n = 1;
899
900	if (size > 8)
901	return AVERROR_INVALIDDATA;
902
903	if (size == 0) {
904	*num = 0;
905	} else {
906	*num = sign_extend(avio_r8(pb), 8);
907
908	/* big-endian ordering; build up number */
909	while (n++ < size)
910	*num = ((uint64_t)*num << 8) | avio_r8(pb);
911	}
912
913	return 0;
914	}
915
916	/*
917	* Read the next element as a float.
918	* 0 is success, < 0 is failure.
919	*/
920	static int ebml_read_float(AVIOContext *pb, int size, double *num)
921	{
922	if (size == 0)
923	*num = 0;
924	else if (size == 4)
925	*num = av_int2float(avio_rb32(pb));
926	else if (size == 8)
927	*num = av_int2double(avio_rb64(pb));
928	else
929	return AVERROR_INVALIDDATA;
930
931	return 0;
932	}
933
934	/*
935	* Read the next element as an ASCII string.
936	* 0 is success, < 0 is failure.
937	*/
938	static int ebml_read_ascii(AVIOContext *pb, int size, char **str)
939	{
940	char *res;
941
942	/* EBML strings are usually not 0-terminated, so we allocate one
943	* byte more, read the string and NULL-terminate it ourselves. */
944	if (!(res = av_malloc(size + 1)))
945	return AVERROR(ENOMEM);
946	if (avio_read(pb, (uint8_t *) res, size) != size) {
947	av_free(res);
948	return AVERROR(EIO);
949	}
950	(res)[size] = '\0';
951	av_free(*str);
952	*str = res;
953
954	return 0;
955	}
956
957	/*
958	* Read the next element as binary data.
959	* 0 is success, < 0 is failure.
960	*/
961	static int ebml_read_binary(AVIOContext *pb, int length, EbmlBin *bin)
962	{
963	av_fast_padded_malloc(&bin->data, &bin->size, length);
964	if (!bin->data)
965	return AVERROR(ENOMEM);
966
967	bin->size = length;
968	bin->pos = avio_tell(pb);
969	if (avio_read(pb, bin->data, length) != length) {
970	av_freep(&bin->data);
971	bin->size = 0;
972	return AVERROR(EIO);
973	}
974
975	return 0;
976	}
977
978	/*
979	* Read the next element, but only the header. The contents
980	* are supposed to be sub-elements which can be read separately.
981	* 0 is success, < 0 is failure.
982	*/
983	static int ebml_read_master(MatroskaDemuxContext *matroska, uint64_t length)
984	{
985	AVIOContext *pb = matroska->ctx->pb;
986	MatroskaLevel *level;
987
988	if (matroska->num_levels >= EBML_MAX_DEPTH) {
989	av_log(matroska->ctx, AV_LOG_ERROR,
990	"File moves beyond max. allowed depth (%d)\n", EBML_MAX_DEPTH);
991	return AVERROR(ENOSYS);
992	}
993
994	level = &matroska->levels[matroska->num_levels++];
995	level->start = avio_tell(pb);
996	level->length = length;
997
998	return 0;
999	}
1000
1001	/*
1002	* Read signed/unsigned "EBML" numbers.
1003	* Return: number of bytes processed, < 0 on error
1004	*/
1005	static int matroska_ebmlnum_uint(MatroskaDemuxContext *matroska,
1006	uint8_t *data, uint32_t size, uint64_t *num)
1007	{
1008	AVIOContext pb;
1009	ffio_init_context(&pb, data, size, 0, NULL, NULL, NULL, NULL);
1010	return ebml_read_num(matroska, &pb, FFMIN(size, 8), num);
1011	}
1012
1013	/*
1014	* Same as above, but signed.
1015	*/
1016	static int matroska_ebmlnum_sint(MatroskaDemuxContext *matroska,
1017	uint8_t *data, uint32_t size, int64_t *num)
1018	{
1019	uint64_t unum;
1020	int res;
1021
1022	/* read as unsigned number first */
1023	if ((res = matroska_ebmlnum_uint(matroska, data, size, &unum)) < 0)
1024	return res;
1025
1026	/* make signed (weird way) */
1027	*num = unum - ((1LL << (7 * res - 1)) - 1);
1028
1029	return res;
1030	}
1031
1032	static int ebml_parse_elem(MatroskaDemuxContext *matroska,
1033	EbmlSyntax *syntax, void *data);
1034
1035	static int ebml_parse_id(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
1036	uint32_t id, void *data)
1037	{
1038	int i;
1039	for (i = 0; syntax[i].id; i++)
1040	if (id == syntax[i].id)
1041	break;
1042	if (!syntax[i].id && id == MATROSKA_ID_CLUSTER &&
1043	matroska->num_levels > 0 &&
1044	matroska->levels[matroska->num_levels - 1].length == 0xffffffffffffff)
1045	return 0; // we reached the end of an unknown size cluster
1046	if (!syntax[i].id && id != EBML_ID_VOID && id != EBML_ID_CRC32) {
1047	av_log(matroska->ctx, AV_LOG_DEBUG, "Unknown entry 0x%"PRIX32"\n", id);
1048	}
1049	return ebml_parse_elem(matroska, &syntax[i], data);
1050	}
1051
1052	static int ebml_parse(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
1053	void *data)
1054	{
1055	if (!matroska->current_id) {
1056	uint64_t id;
1057	int res = ebml_read_num(matroska, matroska->ctx->pb, 4, &id);
1058	if (res < 0) {
1059	// in live mode, finish parsing if EOF is reached.
1060	return (matroska->is_live && matroska->ctx->pb->eof_reached &&
1061	res == AVERROR_EOF) ? 1 : res;
1062	}
1063	matroska->current_id = id | 1 << 7 * res;
1064	}
1065	return ebml_parse_id(matroska, syntax, matroska->current_id, data);
1066	}
1067
1068	static int ebml_parse_nest(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
1069	void *data)
1070	{
1071	int i, res = 0;
1072
1073	for (i = 0; syntax[i].id; i++)
1074	switch (syntax[i].type) {
1075	case EBML_SINT:
1076	*(int64_t *) ((char *) data + syntax[i].data_offset) = syntax[i].def.i;
1077	break;
1078	case EBML_UINT:
1079	*(uint64_t *) ((char *) data + syntax[i].data_offset) = syntax[i].def.u;
1080	break;
1081	case EBML_FLOAT:
1082	*(double *) ((char *) data + syntax[i].data_offset) = syntax[i].def.f;
1083	break;
1084	case EBML_STR:
1085	case EBML_UTF8:
1086	// the default may be NULL
1087	if (syntax[i].def.s) {
1088	uint8_t **dst = (uint8_t **) ((uint8_t *) data + syntax[i].data_offset);
1089	*dst = av_strdup(syntax[i].def.s);
1090	if (!*dst)
1091	return AVERROR(ENOMEM);
1092	}
1093	break;
1094	}
1095
1096	while (!res && !ebml_level_end(matroska))
1097	res = ebml_parse(matroska, syntax, data);
1098
1099	return res;
1100	}
1101
1102	static int is_ebml_id_valid(uint32_t id)
1103	{
1104	// Due to endian nonsense in Matroska, the highest byte with any bits set
1105	// will contain the leading length bit. This bit in turn identifies the
1106	// total byte length of the element by its position within the byte.
1107	unsigned int bits = av_log2(id);
1108	return id && (bits + 7) / 8 == (8 - bits % 8);
1109	}
1110
1111	/*
1112	* Allocate and return the entry for the level1 element with the given ID. If
1113	* an entry already exists, return the existing entry.
1114	*/
1115	static MatroskaLevel1Element *matroska_find_level1_elem(MatroskaDemuxContext *matroska,
1116	uint32_t id)
1117	{
1118	int i;
1119	MatroskaLevel1Element *elem;
1120
1121	if (!is_ebml_id_valid(id))
1122	return NULL;
1123
1124	// Some files link to all clusters; useless.
1125	if (id == MATROSKA_ID_CLUSTER)
1126	return NULL;
1127
1128	// There can be multiple seekheads.
1129	if (id != MATROSKA_ID_SEEKHEAD) {
1130	for (i = 0; i < matroska->num_level1_elems; i++) {
1131	if (matroska->level1_elems[i].id == id)
1132	return &matroska->level1_elems[i];
1133	}
1134	}
1135
1136	// Only a completely broken file would have more elements.
1137	// It also provides a low-effort way to escape from circular seekheads
1138	// (every iteration will add a level1 entry).
1139	if (matroska->num_level1_elems >= FF_ARRAY_ELEMS(matroska->level1_elems)) {
1140	av_log(matroska->ctx, AV_LOG_ERROR, "Too many level1 elements or circular seekheads.\n");
1141	return NULL;
1142	}
1143
1144	elem = &matroska->level1_elems[matroska->num_level1_elems++];
1145	*elem = (MatroskaLevel1Element){.id = id};
1146
1147	return elem;
1148	}
1149
1150	static int ebml_parse_elem(MatroskaDemuxContext *matroska,
1151	EbmlSyntax *syntax, void *data)
1152	{
1153	static const uint64_t max_lengths[EBML_TYPE_COUNT] = {
1154	[EBML_UINT] = 8,
1155	[EBML_FLOAT] = 8,
1156	// max. 16 MB for strings
1157	[EBML_STR] = 0x1000000,
1158	[EBML_UTF8] = 0x1000000,
1159	// max. 256 MB for binary data
1160	[EBML_BIN] = 0x10000000,
1161	// no limits for anything else
1162	};
1163	AVIOContext *pb = matroska->ctx->pb;
1164	uint32_t id = syntax->id;
1165	uint64_t length;
1166	int res;
1167	void *newelem;
1168	MatroskaLevel1Element *level1_elem;
1169
1170	data = (char *) data + syntax->data_offset;
1171	if (syntax->list_elem_size) {
1172	EbmlList *list = data;
1173	newelem = av_realloc_array(list->elem, list->nb_elem + 1, syntax->list_elem_size);
1174	if (!newelem)
1175	return AVERROR(ENOMEM);
1176	list->elem = newelem;
1177	data = (char *) list->elem + list->nb_elem * syntax->list_elem_size;
1178	memset(data, 0, syntax->list_elem_size);
1179	list->nb_elem++;
1180	}
1181
1182	if (syntax->type != EBML_PASS && syntax->type != EBML_STOP) {
1183	matroska->current_id = 0;
1184	if ((res = ebml_read_length(matroska, pb, &length)) < 0)
1185	return res;
1186	if (max_lengths[syntax->type] && length > max_lengths[syntax->type]) {
1187	av_log(matroska->ctx, AV_LOG_ERROR,
1188	"Invalid length 0x%"PRIx64" > 0x%"PRIx64" for syntax element %i\n",
1189	length, max_lengths[syntax->type], syntax->type);
1190	return AVERROR_INVALIDDATA;
1191	}
1192	}
1193
1194	switch (syntax->type) {
1195	case EBML_UINT:
1196	res = ebml_read_uint(pb, length, data);
1197	break;
1198	case EBML_SINT:
1199	res = ebml_read_sint(pb, length, data);
1200	break;
1201	case EBML_FLOAT:
1202	res = ebml_read_float(pb, length, data);
1203	break;
1204	case EBML_STR:
1205	case EBML_UTF8:
1206	res = ebml_read_ascii(pb, length, data);
1207	break;
1208	case EBML_BIN:
1209	res = ebml_read_binary(pb, length, data);
1210	break;
1211	case EBML_LEVEL1:
1212	case EBML_NEST:
1213	if ((res = ebml_read_master(matroska, length)) < 0)
1214	return res;
1215	if (id == MATROSKA_ID_SEGMENT)
1216	matroska->segment_start = avio_tell(matroska->ctx->pb);
1217	if (id == MATROSKA_ID_CUES)
1218	matroska->cues_parsing_deferred = 0;
1219	if (syntax->type == EBML_LEVEL1 &&
1220	(level1_elem = matroska_find_level1_elem(matroska, syntax->id))) {
1221	if (level1_elem->parsed)
1222	av_log(matroska->ctx, AV_LOG_ERROR, "Duplicate element\n");
1223	level1_elem->parsed = 1;
1224	}
1225	return ebml_parse_nest(matroska, syntax->def.n, data);
1226	case EBML_PASS:
1227	return ebml_parse_id(matroska, syntax->def.n, id, data);
1228	case EBML_STOP:
1229	return 1;
1230	default:
1231	if (ffio_limit(pb, length) != length)
1232	return AVERROR(EIO);
1233	return avio_skip(pb, length) < 0 ? AVERROR(EIO) : 0;
1234	}
1235	if (res == AVERROR_INVALIDDATA)
1236	av_log(matroska->ctx, AV_LOG_ERROR, "Invalid element\n");
1237	else if (res == AVERROR(EIO))
1238	av_log(matroska->ctx, AV_LOG_ERROR, "Read error\n");
1239	return res;
1240	}
1241
1242	static void ebml_free(EbmlSyntax *syntax, void *data)
1243	{
1244	int i, j;
1245	for (i = 0; syntax[i].id; i++) {
1246	void *data_off = (char *) data + syntax[i].data_offset;
1247	switch (syntax[i].type) {
1248	case EBML_STR:
1249	case EBML_UTF8:
1250	av_freep(data_off);
1251	break;
1252	case EBML_BIN:
1253	av_freep(&((EbmlBin *) data_off)->data);
1254	break;
1255	case EBML_LEVEL1:
1256	case EBML_NEST:
1257	if (syntax[i].list_elem_size) {
1258	EbmlList *list = data_off;
1259	char *ptr = list->elem;
1260	for (j = 0; j < list->nb_elem;
1261	j++, ptr += syntax[i].list_elem_size)
1262	ebml_free(syntax[i].def.n, ptr);
1263	av_freep(&list->elem);
1264	list->nb_elem = 0;
1265	} else
1266	ebml_free(syntax[i].def.n, data_off);
1267	default:
1268	break;
1269	}
1270	}
1271	}
1272
1273	/*
1274	* Autodetecting...
1275	*/
1276	static int matroska_probe(AVProbeData *p)
1277	{
1278	uint64_t total = 0;
1279	int len_mask = 0x80, size = 1, n = 1, i;
1280
1281	/* EBML header? */
1282	if (AV_RB32(p->buf) != EBML_ID_HEADER)
1283	return 0;
1284
1285	/* length of header */
1286	total = p->buf[4];
1287	while (size <= 8 && !(total & len_mask)) {
1288	size++;
1289	len_mask >>= 1;
1290	}
1291	if (size > 8)
1292	return 0;
1293	total &= (len_mask - 1);
1294	while (n < size)
1295	total = (total << 8) | p->buf[4 + n++];
1296
1297	/* Does the probe data contain the whole header? */
1298	if (p->buf_size < 4 + size + total)
1299	return 0;
1300
1301	/* The header should contain a known document type. For now,
1302	* we don't parse the whole header but simply check for the
1303	* availability of that array of characters inside the header.
1304	* Not fully fool-proof, but good enough. */
1305	for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++) {
1306	size_t probelen = strlen(matroska_doctypes[i]);
1307	if (total < probelen)
1308	continue;
1309	for (n = 4 + size; n <= 4 + size + total - probelen; n++)
1310	if (!memcmp(p->buf + n, matroska_doctypes[i], probelen))
1311	return AVPROBE_SCORE_MAX;
1312	}
1313
1314	// probably valid EBML header but no recognized doctype
1315	return AVPROBE_SCORE_EXTENSION;
1316	}
1317
1318	static MatroskaTrack *matroska_find_track_by_num(MatroskaDemuxContext *matroska,
1319	int num)
1320	{
1321	MatroskaTrack *tracks = matroska->tracks.elem;
1322	int i;
1323
1324	for (i = 0; i < matroska->tracks.nb_elem; i++)
1325	if (tracks[i].num == num)
1326	return &tracks[i];
1327
1328	av_log(matroska->ctx, AV_LOG_ERROR, "Invalid track number %d\n", num);
1329	return NULL;
1330	}
1331
1332	static int matroska_decode_buffer(uint8_t **buf, int *buf_size,
1333	MatroskaTrack *track)
1334	{
1335	MatroskaTrackEncoding *encodings = track->encodings.elem;
1336	uint8_t *data = *buf;
1337	int isize = *buf_size;
1338	uint8_t *pkt_data = NULL;
1339	uint8_t av_unused *newpktdata;
1340	int pkt_size = isize;
1341	int result = 0;
1342	int olen;
1343
1344	if (pkt_size >= 10000000U)
1345	return AVERROR_INVALIDDATA;
1346
1347	switch (encodings[0].compression.algo) {
1348	case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP:
1349	{
1350	int header_size = encodings[0].compression.settings.size;
1351	uint8_t *header = encodings[0].compression.settings.data;
1352
1353	if (header_size && !header) {
1354	av_log(NULL, AV_LOG_ERROR, "Compression size but no data in headerstrip\n");
1355	return -1;
1356	}
1357
1358	if (!header_size)
1359	return 0;
1360
1361	pkt_size = isize + header_size;
1362	pkt_data = av_malloc(pkt_size);
1363	if (!pkt_data)
1364	return AVERROR(ENOMEM);
1365
1366	memcpy(pkt_data, header, header_size);
1367	memcpy(pkt_data + header_size, data, isize);
1368	break;
1369	}
1370	#if CONFIG_LZO
1371	case MATROSKA_TRACK_ENCODING_COMP_LZO:
1372	do {
1373	olen = pkt_size *= 3;
1374	newpktdata = av_realloc(pkt_data, pkt_size + AV_LZO_OUTPUT_PADDING);
1375	if (!newpktdata) {
1376	result = AVERROR(ENOMEM);
1377	goto failed;
1378	}
1379	pkt_data = newpktdata;
1380	result = av_lzo1x_decode(pkt_data, &olen, data, &isize);
1381	} while (result == AV_LZO_OUTPUT_FULL && pkt_size < 10000000);
1382	if (result) {
1383	result = AVERROR_INVALIDDATA;
1384	goto failed;
1385	}
1386	pkt_size -= olen;
1387	break;
1388	#endif
1389	#if CONFIG_ZLIB
1390	case MATROSKA_TRACK_ENCODING_COMP_ZLIB:
1391	{
1392	z_stream zstream = { 0 };
1393	if (inflateInit(&zstream) != Z_OK)
1394	return -1;
1395	zstream.next_in = data;
1396	zstream.avail_in = isize;
1397	do {
1398	pkt_size *= 3;
1399	newpktdata = av_realloc(pkt_data, pkt_size);
1400	if (!newpktdata) {
1401	inflateEnd(&zstream);
1402	result = AVERROR(ENOMEM);
1403	goto failed;
1404	}
1405	pkt_data = newpktdata;
1406	zstream.avail_out = pkt_size - zstream.total_out;
1407	zstream.next_out = pkt_data + zstream.total_out;
1408	result = inflate(&zstream, Z_NO_FLUSH);
1409	} while (result == Z_OK && pkt_size < 10000000);
1410	pkt_size = zstream.total_out;
1411	inflateEnd(&zstream);
1412	if (result != Z_STREAM_END) {
1413	if (result == Z_MEM_ERROR)
1414	result = AVERROR(ENOMEM);
1415	else
1416	result = AVERROR_INVALIDDATA;
1417	goto failed;
1418	}
1419	break;
1420	}
1421	#endif
1422	#if CONFIG_BZLIB
1423	case MATROSKA_TRACK_ENCODING_COMP_BZLIB:
1424	{
1425	bz_stream bzstream = { 0 };
1426	if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
1427	return -1;
1428	bzstream.next_in = data;
1429	bzstream.avail_in = isize;
1430	do {
1431	pkt_size *= 3;
1432	newpktdata = av_realloc(pkt_data, pkt_size);
1433	if (!newpktdata) {
1434	BZ2_bzDecompressEnd(&bzstream);
1435	result = AVERROR(ENOMEM);
1436	goto failed;
1437	}
1438	pkt_data = newpktdata;
1439	bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
1440	bzstream.next_out = pkt_data + bzstream.total_out_lo32;
1441	result = BZ2_bzDecompress(&bzstream);
1442	} while (result == BZ_OK && pkt_size < 10000000);
1443	pkt_size = bzstream.total_out_lo32;
1444	BZ2_bzDecompressEnd(&bzstream);
1445	if (result != BZ_STREAM_END) {
1446	if (result == BZ_MEM_ERROR)
1447	result = AVERROR(ENOMEM);
1448	else
1449	result = AVERROR_INVALIDDATA;
1450	goto failed;
1451	}
1452	break;
1453	}
1454	#endif
1455	default:
1456	return AVERROR_INVALIDDATA;
1457	}
1458
1459	*buf = pkt_data;
1460	*buf_size = pkt_size;
1461	return 0;
1462
1463	failed:
1464	av_free(pkt_data);
1465	return result;
1466	}
1467
1468	static void matroska_convert_tag(AVFormatContext *s, EbmlList *list,
1469	AVDictionary **metadata, char *prefix)
1470	{
1471	MatroskaTag *tags = list->elem;
1472	char key[1024];
1473	int i;
1474
1475	for (i = 0; i < list->nb_elem; i++) {
1476	const char *lang = tags[i].lang &&
1477	strcmp(tags[i].lang, "und") ? tags[i].lang : NULL;
1478
1479	if (!tags[i].name) {
1480	av_log(s, AV_LOG_WARNING, "Skipping invalid tag with no TagName.\n");
1481	continue;
1482	}
1483	if (prefix)
1484	snprintf(key, sizeof(key), "%s/%s", prefix, tags[i].name);
1485	else
1486	av_strlcpy(key, tags[i].name, sizeof(key));
1487	if (tags[i].def || !lang) {
1488	av_dict_set(metadata, key, tags[i].string, 0);
1489	if (tags[i].sub.nb_elem)
1490	matroska_convert_tag(s, &tags[i].sub, metadata, key);
1491	}
1492	if (lang) {
1493	av_strlcat(key, "-", sizeof(key));
1494	av_strlcat(key, lang, sizeof(key));
1495	av_dict_set(metadata, key, tags[i].string, 0);
1496	if (tags[i].sub.nb_elem)
1497	matroska_convert_tag(s, &tags[i].sub, metadata, key);
1498	}
1499	}
1500	ff_metadata_conv(metadata, NULL, ff_mkv_metadata_conv);
1501	}
1502
1503	static void matroska_convert_tags(AVFormatContext *s)
1504	{
1505	MatroskaDemuxContext *matroska = s->priv_data;
1506	MatroskaTags *tags = matroska->tags.elem;
1507	int i, j;
1508
1509	for (i = 0; i < matroska->tags.nb_elem; i++) {
1510	if (tags[i].target.attachuid) {
1511	MatroskaAttachment *attachment = matroska->attachments.elem;
1512	int found = 0;
1513	for (j = 0; j < matroska->attachments.nb_elem; j++) {
1514	if (attachment[j].uid == tags[i].target.attachuid &&
1515	attachment[j].stream) {
1516	matroska_convert_tag(s, &tags[i].tag,
1517	&attachment[j].stream->metadata, NULL);
1518	found = 1;
1519	}
1520	}
1521	if (!found) {
1522	av_log(NULL, AV_LOG_WARNING,
1523	"The tags at index %d refer to a "
1524	"non-existent attachment %"PRId64".\n",
1525	i, tags[i].target.attachuid);
1526	}
1527	} else if (tags[i].target.chapteruid) {
1528	MatroskaChapter *chapter = matroska->chapters.elem;
1529	int found = 0;
1530	for (j = 0; j < matroska->chapters.nb_elem; j++) {
1531	if (chapter[j].uid == tags[i].target.chapteruid &&
1532	chapter[j].chapter) {
1533	matroska_convert_tag(s, &tags[i].tag,
1534	&chapter[j].chapter->metadata, NULL);
1535	found = 1;
1536	}
1537	}
1538	if (!found) {
1539	av_log(NULL, AV_LOG_WARNING,
1540	"The tags at index %d refer to a non-existent chapter "
1541	"%"PRId64".\n",
1542	i, tags[i].target.chapteruid);
1543	}
1544	} else if (tags[i].target.trackuid) {
1545	MatroskaTrack *track = matroska->tracks.elem;
1546	int found = 0;
1547	for (j = 0; j < matroska->tracks.nb_elem; j++) {
1548	if (track[j].uid == tags[i].target.trackuid &&
1549	track[j].stream) {
1550	matroska_convert_tag(s, &tags[i].tag,
1551	&track[j].stream->metadata, NULL);
1552	found = 1;
1553	}
1554	}
1555	if (!found) {
1556	av_log(NULL, AV_LOG_WARNING,
1557	"The tags at index %d refer to a non-existent track "
1558	"%"PRId64".\n",
1559	i, tags[i].target.trackuid);
1560	}
1561	} else {
1562	matroska_convert_tag(s, &tags[i].tag, &s->metadata,
1563	tags[i].target.type);
1564	}
1565	}
1566	}
1567
1568	static int matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska,
1569	uint64_t pos)
1570	{
1571	uint32_t level_up = matroska->level_up;
1572	uint32_t saved_id = matroska->current_id;
1573	int64_t before_pos = avio_tell(matroska->ctx->pb);
1574	MatroskaLevel level;
1575	int64_t offset;
1576	int ret = 0;
1577
1578	/* seek */
1579	offset = pos + matroska->segment_start;
1580	if (avio_seek(matroska->ctx->pb, offset, SEEK_SET) == offset) {
1581	/* We don't want to lose our seekhead level, so we add
1582	* a dummy. This is a crude hack. */
1583	if (matroska->num_levels == EBML_MAX_DEPTH) {
1584	av_log(matroska->ctx, AV_LOG_INFO,
1585	"Max EBML element depth (%d) reached, "
1586	"cannot parse further.\n", EBML_MAX_DEPTH);
1587	ret = AVERROR_INVALIDDATA;
1588	} else {
1589	level.start = 0;
1590	level.length = (uint64_t) -1;
1591	matroska->levels[matroska->num_levels] = level;
1592	matroska->num_levels++;
1593	matroska->current_id = 0;
1594
1595	ret = ebml_parse(matroska, matroska_segment, matroska);
1596
1597	/* remove dummy level */
1598	while (matroska->num_levels) {
1599	uint64_t length = matroska->levels[--matroska->num_levels].length;
1600	if (length == (uint64_t) -1)
1601	break;
1602	}
1603	}
1604	}
1605	/* seek back */
1606	avio_seek(matroska->ctx->pb, before_pos, SEEK_SET);
1607	matroska->level_up = level_up;
1608	matroska->current_id = saved_id;
1609
1610	return ret;
1611	}
1612
1613	static void matroska_execute_seekhead(MatroskaDemuxContext *matroska)
1614	{
1615	EbmlList *seekhead_list = &matroska->seekhead;
1616	int i;
1617
1618	// we should not do any seeking in the streaming case
1619	if (!(matroska->ctx->pb->seekable & AVIO_SEEKABLE_NORMAL))
1620	return;
1621
1622	for (i = 0; i < seekhead_list->nb_elem; i++) {
1623	MatroskaSeekhead *seekheads = seekhead_list->elem;
1624	uint32_t id = seekheads[i].id;
1625	uint64_t pos = seekheads[i].pos;
1626
1627	MatroskaLevel1Element *elem = matroska_find_level1_elem(matroska, id);
1628	if (!elem || elem->parsed)
1629	continue;
1630
1631	elem->pos = pos;
1632
1633	// defer cues parsing until we actually need cue data.
1634	if (id == MATROSKA_ID_CUES)
1635	continue;
1636
1637	if (matroska_parse_seekhead_entry(matroska, pos) < 0) {
1638	// mark index as broken
1639	matroska->cues_parsing_deferred = -1;
1640	break;
1641	}
1642
1643	elem->parsed = 1;
1644	}
1645	}
1646
1647	static void matroska_add_index_entries(MatroskaDemuxContext *matroska)
1648	{
1649	EbmlList *index_list;
1650	MatroskaIndex *index;
1651	uint64_t index_scale = 1;
1652	int i, j;
1653
1654	if (matroska->ctx->flags & AVFMT_FLAG_IGNIDX)
1655	return;
1656
1657	index_list = &matroska->index;
1658	index = index_list->elem;
1659	if (index_list->nb_elem < 2)
1660	return;
1661	if (index[1].time > 1E14 / matroska->time_scale) {
1662	av_log(matroska->ctx, AV_LOG_WARNING, "Dropping apparently-broken index.\n");
1663	return;
1664	}
1665	for (i = 0; i < index_list->nb_elem; i++) {
1666	EbmlList *pos_list = &index[i].pos;
1667	MatroskaIndexPos *pos = pos_list->elem;
1668	for (j = 0; j < pos_list->nb_elem; j++) {
1669	MatroskaTrack *track = matroska_find_track_by_num(matroska,
1670	pos[j].track);
1671	if (track && track->stream)
1672	av_add_index_entry(track->stream,
1673	pos[j].pos + matroska->segment_start,
1674	index[i].time / index_scale, 0, 0,
1675	AVINDEX_KEYFRAME);
1676	}
1677	}
1678	}
1679
1680	static void matroska_parse_cues(MatroskaDemuxContext *matroska) {
1681	int i;
1682
1683	if (matroska->ctx->flags & AVFMT_FLAG_IGNIDX)
1684	return;
1685
1686	for (i = 0; i < matroska->num_level1_elems; i++) {
1687	MatroskaLevel1Element *elem = &matroska->level1_elems[i];
1688	if (elem->id == MATROSKA_ID_CUES && !elem->parsed) {
1689	if (matroska_parse_seekhead_entry(matroska, elem->pos) < 0)
1690	matroska->cues_parsing_deferred = -1;
1691	elem->parsed = 1;
1692	break;
1693	}
1694	}
1695
1696	matroska_add_index_entries(matroska);
1697	}
1698
1699	static int matroska_aac_profile(char *codec_id)
1700	{
1701	static const char *const aac_profiles[] = { "MAIN", "LC", "SSR" };
1702	int profile;
1703
1704	for (profile = 0; profile < FF_ARRAY_ELEMS(aac_profiles); profile++)
1705	if (strstr(codec_id, aac_profiles[profile]))
1706	break;
1707	return profile + 1;
1708	}
1709
1710	static int matroska_aac_sri(int samplerate)
1711	{
1712	int sri;
1713
1714	for (sri = 0; sri < FF_ARRAY_ELEMS(avpriv_mpeg4audio_sample_rates); sri++)
1715	if (avpriv_mpeg4audio_sample_rates[sri] == samplerate)
1716	break;
1717	return sri;
1718	}
1719
1720	static void matroska_metadata_creation_time(AVDictionary **metadata, int64_t date_utc)
1721	{
1722	/* Convert to seconds and adjust by number of seconds between 2001-01-01 and Epoch */
1723	avpriv_dict_set_timestamp(metadata, "creation_time", date_utc / 1000 + 978307200000000LL);
1724	}
1725
1726	static int matroska_parse_flac(AVFormatContext *s,
1727	MatroskaTrack *track,
1728	int *offset)
1729	{
1730	AVStream *st = track->stream;
1731	uint8_t *p = track->codec_priv.data;
1732	int size = track->codec_priv.size;
1733
1734	if (size < 8 + FLAC_STREAMINFO_SIZE || p[4] & 0x7f) {
1735	av_log(s, AV_LOG_WARNING, "Invalid FLAC private data\n");
1736	track->codec_priv.size = 0;
1737	return 0;
1738	}
1739	*offset = 8;
1740	track->codec_priv.size = 8 + FLAC_STREAMINFO_SIZE;
1741
1742	p += track->codec_priv.size;
1743	size -= track->codec_priv.size;
1744
1745	/* parse the remaining metadata blocks if present */
1746	while (size >= 4) {
1747	int block_last, block_type, block_size;
1748
1749	flac_parse_block_header(p, &block_last, &block_type, &block_size);
1750
1751	p += 4;
1752	size -= 4;
1753	if (block_size > size)
1754	return 0;
1755
1756	/* check for the channel mask */
1757	if (block_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
1758	AVDictionary *dict = NULL;
1759	AVDictionaryEntry *chmask;
1760
1761	ff_vorbis_comment(s, &dict, p, block_size, 0);
1762	chmask = av_dict_get(dict, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
1763	if (chmask) {
1764	uint64_t mask = strtol(chmask->value, NULL, 0);
1765	if (!mask || mask & ~0x3ffffULL) {
1766	av_log(s, AV_LOG_WARNING,
1767	"Invalid value of WAVEFORMATEXTENSIBLE_CHANNEL_MASK\n");
1768	} else
1769	st->codecpar->channel_layout = mask;
1770	}
1771	av_dict_free(&dict);
1772	}
1773
1774	p += block_size;
1775	size -= block_size;
1776	}
1777
1778	return 0;
1779	}
1780
1781	static int mkv_field_order(MatroskaDemuxContext *matroska, int64_t field_order)
1782	{
1783	int major, minor, micro, bttb = 0;
1784
1785	/* workaround a bug in our Matroska muxer, introduced in version 57.36 alongside
1786	* this function, and fixed in 57.52 */
1787	if (matroska->muxingapp && sscanf(matroska->muxingapp, "Lavf%d.%d.%d", &major, &minor, &micro) == 3)
1788	bttb = (major == 57 && minor >= 36 && minor <= 51 && micro >= 100);
1789
1790	switch (field_order) {
1791	case MATROSKA_VIDEO_FIELDORDER_PROGRESSIVE:
1792	return AV_FIELD_PROGRESSIVE;
1793	case MATROSKA_VIDEO_FIELDORDER_UNDETERMINED:
1794	return AV_FIELD_UNKNOWN;
1795	case MATROSKA_VIDEO_FIELDORDER_TT:
1796	return AV_FIELD_TT;
1797	case MATROSKA_VIDEO_FIELDORDER_BB:
1798	return AV_FIELD_BB;
1799	case MATROSKA_VIDEO_FIELDORDER_BT:
1800	return bttb ? AV_FIELD_TB : AV_FIELD_BT;
1801	case MATROSKA_VIDEO_FIELDORDER_TB:
1802	return bttb ? AV_FIELD_BT : AV_FIELD_TB;
1803	default:
1804	return AV_FIELD_UNKNOWN;
1805	}
1806	}
1807
1808	static void mkv_stereo_mode_display_mul(int stereo_mode,
1809	int *h_width, int *h_height)
1810	{
1811	switch (stereo_mode) {
1812	case MATROSKA_VIDEO_STEREOMODE_TYPE_MONO:
1813	case MATROSKA_VIDEO_STEREOMODE_TYPE_CHECKERBOARD_RL:
1814	case MATROSKA_VIDEO_STEREOMODE_TYPE_CHECKERBOARD_LR:
1815	case MATROSKA_VIDEO_STEREOMODE_TYPE_BOTH_EYES_BLOCK_RL:
1816	case MATROSKA_VIDEO_STEREOMODE_TYPE_BOTH_EYES_BLOCK_LR:
1817	break;
1818	case MATROSKA_VIDEO_STEREOMODE_TYPE_RIGHT_LEFT:
1819	case MATROSKA_VIDEO_STEREOMODE_TYPE_LEFT_RIGHT:
1820	case MATROSKA_VIDEO_STEREOMODE_TYPE_COL_INTERLEAVED_RL:
1821	case MATROSKA_VIDEO_STEREOMODE_TYPE_COL_INTERLEAVED_LR:
1822	*h_width = 2;
1823	break;
1824	case MATROSKA_VIDEO_STEREOMODE_TYPE_BOTTOM_TOP:
1825	case MATROSKA_VIDEO_STEREOMODE_TYPE_TOP_BOTTOM:
1826	case MATROSKA_VIDEO_STEREOMODE_TYPE_ROW_INTERLEAVED_RL:
1827	case MATROSKA_VIDEO_STEREOMODE_TYPE_ROW_INTERLEAVED_LR:
1828	*h_height = 2;
1829	break;
1830	}
1831	}
1832
1833	static int mkv_parse_video_color(AVStream *st, const MatroskaTrack *track) {
1834	const MatroskaTrackVideoColor *color = track->video.color.elem;
1835	const MatroskaMasteringMeta *mastering_meta;
1836	int has_mastering_primaries, has_mastering_luminance;
1837
1838	if (!track->video.color.nb_elem)
1839	return 0;
1840
1841	mastering_meta = &color->mastering_meta;
1842	// Mastering primaries are CIE 1931 coords, and must be > 0.
1843	has_mastering_primaries =
1844	mastering_meta->r_x > 0 && mastering_meta->r_y > 0 &&
1845	mastering_meta->g_x > 0 && mastering_meta->g_y > 0 &&
1846	mastering_meta->b_x > 0 && mastering_meta->b_y > 0 &&
1847	mastering_meta->white_x > 0 && mastering_meta->white_y > 0;
1848	has_mastering_luminance = mastering_meta->max_luminance > 0;
1849
1850	if (color->matrix_coefficients != AVCOL_SPC_RESERVED)
1851	st->codecpar->color_space = color->matrix_coefficients;
1852	if (color->primaries != AVCOL_PRI_RESERVED &&
1853	color->primaries != AVCOL_PRI_RESERVED0)
1854	st->codecpar->color_primaries = color->primaries;
1855	if (color->transfer_characteristics != AVCOL_TRC_RESERVED &&
1856	color->transfer_characteristics != AVCOL_TRC_RESERVED0)
1857	st->codecpar->color_trc = color->transfer_characteristics;
1858	if (color->range != AVCOL_RANGE_UNSPECIFIED &&
1859	color->range <= AVCOL_RANGE_JPEG)
1860	st->codecpar->color_range = color->range;
1861	if (color->chroma_siting_horz != MATROSKA_COLOUR_CHROMASITINGHORZ_UNDETERMINED &&
1862	color->chroma_siting_vert != MATROSKA_COLOUR_CHROMASITINGVERT_UNDETERMINED &&
1863	color->chroma_siting_horz < MATROSKA_COLOUR_CHROMASITINGHORZ_NB &&
1864	color->chroma_siting_vert < MATROSKA_COLOUR_CHROMASITINGVERT_NB) {
1865	st->codecpar->chroma_location =
1866	avcodec_chroma_pos_to_enum((color->chroma_siting_horz - 1) << 7,
1867	(color->chroma_siting_vert - 1) << 7);
1868	}
1869
1870	if (has_mastering_primaries || has_mastering_luminance) {
1871	// Use similar rationals as other standards.
1872	const int chroma_den = 50000;
1873	const int luma_den = 10000;
1874	AVMasteringDisplayMetadata *metadata =
1875	(AVMasteringDisplayMetadata*) av_stream_new_side_data(
1876	st, AV_PKT_DATA_MASTERING_DISPLAY_METADATA,
1877	sizeof(AVMasteringDisplayMetadata));
1878	if (!metadata) {
1879	return AVERROR(ENOMEM);
1880	}
1881	memset(metadata, 0, sizeof(AVMasteringDisplayMetadata));
1882	if (has_mastering_primaries) {
1883	metadata->display_primaries[0][0] = av_make_q(
1884	round(mastering_meta->r_x * chroma_den), chroma_den);
1885	metadata->display_primaries[0][1] = av_make_q(
1886	round(mastering_meta->r_y * chroma_den), chroma_den);
1887	metadata->display_primaries[1][0] = av_make_q(
1888	round(mastering_meta->g_x * chroma_den), chroma_den);
1889	metadata->display_primaries[1][1] = av_make_q(
1890	round(mastering_meta->g_y * chroma_den), chroma_den);
1891	metadata->display_primaries[2][0] = av_make_q(
1892	round(mastering_meta->b_x * chroma_den), chroma_den);
1893	metadata->display_primaries[2][1] = av_make_q(
1894	round(mastering_meta->b_y * chroma_den), chroma_den);
1895	metadata->white_point[0] = av_make_q(
1896	round(mastering_meta->white_x * chroma_den), chroma_den);
1897	metadata->white_point[1] = av_make_q(
1898	round(mastering_meta->white_y * chroma_den), chroma_den);
1899	metadata->has_primaries = 1;
1900	}
1901	if (has_mastering_luminance) {
1902	metadata->max_luminance = av_make_q(
1903	round(mastering_meta->max_luminance * luma_den), luma_den);
1904	metadata->min_luminance = av_make_q(
1905	round(mastering_meta->min_luminance * luma_den), luma_den);
1906	metadata->has_luminance = 1;
1907	}
1908	}
1909	return 0;
1910	}
1911
1912	static int mkv_parse_video_projection(AVStream *st, const MatroskaTrack *track) {
1913	AVSphericalMapping *spherical;
1914	enum AVSphericalProjection projection;
1915	size_t spherical_size;
1916	uint32_t l = 0, t = 0, r = 0, b = 0;
1917	uint32_t padding = 0;
1918	int ret;
1919	GetByteContext gb;
1920
1921	bytestream2_init(&gb, track->video.projection.private.data,
1922	track->video.projection.private.size);
1923
1924	if (bytestream2_get_byte(&gb) != 0) {
1925	av_log(NULL, AV_LOG_WARNING, "Unknown spherical metadata\n");
1926	return 0;
1927	}
1928
1929	bytestream2_skip(&gb, 3); // flags
1930
1931	switch (track->video.projection.type) {
1932	case MATROSKA_VIDEO_PROJECTION_TYPE_EQUIRECTANGULAR:
1933	if (track->video.projection.private.size == 20) {
1934	t = bytestream2_get_be32(&gb);
1935	b = bytestream2_get_be32(&gb);
1936	l = bytestream2_get_be32(&gb);
1937	r = bytestream2_get_be32(&gb);
1938
1939	if (b >= UINT_MAX - t || r >= UINT_MAX - l) {
1940	av_log(NULL, AV_LOG_ERROR,
1941	"Invalid bounding rectangle coordinates "
1942	"%"PRIu32",%"PRIu32",%"PRIu32",%"PRIu32"\n",
1943	l, t, r, b);
1944	return AVERROR_INVALIDDATA;
1945	}
1946	} else if (track->video.projection.private.size != 0) {
1947	av_log(NULL, AV_LOG_ERROR, "Unknown spherical metadata\n");
1948	return AVERROR_INVALIDDATA;
1949	}
1950
1951	if (l || t || r || b)
1952	projection = AV_SPHERICAL_EQUIRECTANGULAR_TILE;
1953	else
1954	projection = AV_SPHERICAL_EQUIRECTANGULAR;
1955	break;
1956	case MATROSKA_VIDEO_PROJECTION_TYPE_CUBEMAP:
1957	if (track->video.projection.private.size < 4) {
1958	av_log(NULL, AV_LOG_ERROR, "Missing projection private properties\n");
1959	return AVERROR_INVALIDDATA;
1960	} else if (track->video.projection.private.size == 12) {
1961	uint32_t layout = bytestream2_get_be32(&gb);
1962	if (layout) {
1963	av_log(NULL, AV_LOG_WARNING,
1964	"Unknown spherical cubemap layout %"PRIu32"\n", layout);
1965	return 0;
1966	}
1967	projection = AV_SPHERICAL_CUBEMAP;
1968	padding = bytestream2_get_be32(&gb);
1969	} else {
1970	av_log(NULL, AV_LOG_ERROR, "Unknown spherical metadata\n");
1971	return AVERROR_INVALIDDATA;
1972	}
1973	break;
1974	default:
1975	return 0;
1976	}
1977
1978	spherical = av_spherical_alloc(&spherical_size);
1979	if (!spherical)
1980	return AVERROR(ENOMEM);
1981	spherical->projection = projection;
1982
1983	spherical->yaw = (int32_t)(track->video.projection.yaw * (1 << 16));
1984	spherical->pitch = (int32_t)(track->video.projection.pitch * (1 << 16));
1985	spherical->roll = (int32_t)(track->video.projection.roll * (1 << 16));
1986
1987	spherical->padding = padding;
1988
1989	spherical->bound_left = l;
1990	spherical->bound_top = t;
1991	spherical->bound_right = r;
1992	spherical->bound_bottom = b;
1993
1994	ret = av_stream_add_side_data(st, AV_PKT_DATA_SPHERICAL, (uint8_t *)spherical,
1995	spherical_size);
1996	if (ret < 0) {
1997	av_freep(&spherical);
1998	return ret;
1999	}
2000
2001	return 0;
2002	}
2003
2004	static int get_qt_codec(MatroskaTrack *track, uint32_t *fourcc, enum AVCodecID *codec_id)
2005	{
2006	const AVCodecTag *codec_tags;
2007
2008	codec_tags = track->type == MATROSKA_TRACK_TYPE_VIDEO ?
2009	ff_codec_movvideo_tags : ff_codec_movaudio_tags;
2010
2011	/* Normalize noncompliant private data that starts with the fourcc
2012	* by expanding/shifting the data by 4 bytes and storing the data
2013	* size at the start. */
2014	if (ff_codec_get_id(codec_tags, AV_RL32(track->codec_priv.data))) {
2015	uint8_t *p = av_realloc(track->codec_priv.data,
2016	track->codec_priv.size + 4);
2017	if (!p)
2018	return AVERROR(ENOMEM);
2019	memmove(p + 4, p, track->codec_priv.size);
2020	track->codec_priv.data = p;
2021	track->codec_priv.size += 4;
2022	AV_WB32(track->codec_priv.data, track->codec_priv.size);
2023	}
2024
2025	*fourcc = AV_RL32(track->codec_priv.data + 4);
2026	*codec_id = ff_codec_get_id(codec_tags, *fourcc);
2027
2028	return 0;
2029	}
2030
2031	static int matroska_parse_tracks(AVFormatContext *s)
2032	{
2033	MatroskaDemuxContext *matroska = s->priv_data;
2034	MatroskaTrack *tracks = matroska->tracks.elem;
2035	AVStream *st;
2036	int i, j, ret;
2037	int k;
2038
2039	for (i = 0; i < matroska->tracks.nb_elem; i++) {
2040	MatroskaTrack *track = &tracks[i];
2041	enum AVCodecID codec_id = AV_CODEC_ID_NONE;
2042	EbmlList *encodings_list = &track->encodings;
2043	MatroskaTrackEncoding *encodings = encodings_list->elem;
2044	uint8_t *extradata = NULL;
2045	int extradata_size = 0;
2046	int extradata_offset = 0;
2047	uint32_t fourcc = 0;
2048	AVIOContext b;
2049	char* key_id_base64 = NULL;
2050	int bit_depth = -1;
2051
2052	/* Apply some sanity checks. */
2053	if (track->type != MATROSKA_TRACK_TYPE_VIDEO &&
2054	track->type != MATROSKA_TRACK_TYPE_AUDIO &&
2055	track->type != MATROSKA_TRACK_TYPE_SUBTITLE &&
2056	track->type != MATROSKA_TRACK_TYPE_METADATA) {
2057	av_log(matroska->ctx, AV_LOG_INFO,
2058	"Unknown or unsupported track type %"PRIu64"\n",
2059	track->type);
2060	continue;
2061	}
2062	if (!track->codec_id)
2063	continue;
2064
2065	if (track->audio.samplerate < 0 || track->audio.samplerate > INT_MAX ||
2066	isnan(track->audio.samplerate)) {
2067	av_log(matroska->ctx, AV_LOG_WARNING,
2068	"Invalid sample rate %f, defaulting to 8000 instead.\n",
2069	track->audio.samplerate);
2070	track->audio.samplerate = 8000;
2071	}
2072
2073	if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
2074	if (!track->default_duration && track->video.frame_rate > 0)
2075	track->default_duration = 1000000000 / track->video.frame_rate;
2076	if (track->video.display_width == -1)
2077	track->video.display_width = track->video.pixel_width;
2078	if (track->video.display_height == -1)
2079	track->video.display_height = track->video.pixel_height;
2080	if (track->video.color_space.size == 4)
2081	fourcc = AV_RL32(track->video.color_space.data);
2082	} else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
2083	if (!track->audio.out_samplerate)
2084	track->audio.out_samplerate = track->audio.samplerate;
2085	}
2086	if (encodings_list->nb_elem > 1) {
2087	av_log(matroska->ctx, AV_LOG_ERROR,
2088	"Multiple combined encodings not supported");
2089	} else if (encodings_list->nb_elem == 1) {
2090	if (encodings[0].type) {
2091	if (encodings[0].encryption.key_id.size > 0) {
2092	/* Save the encryption key id to be stored later as a
2093	metadata tag. */
2094	const int b64_size = AV_BASE64_SIZE(encodings[0].encryption.key_id.size);
2095	key_id_base64 = av_malloc(b64_size);
2096	if (key_id_base64 == NULL)
2097	return AVERROR(ENOMEM);
2098
2099	av_base64_encode(key_id_base64, b64_size,
2100	encodings[0].encryption.key_id.data,
2101	encodings[0].encryption.key_id.size);
2102	} else {
2103	encodings[0].scope = 0;
2104	av_log(matroska->ctx, AV_LOG_ERROR,
2105	"Unsupported encoding type");
2106	}
2107	} else if (
2108	#if CONFIG_ZLIB
2109	encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_ZLIB &&
2110	#endif
2111	#if CONFIG_BZLIB
2112	encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_BZLIB &&
2113	#endif
2114	#if CONFIG_LZO
2115	encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_LZO &&
2116	#endif
2117	encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP) {
2118	encodings[0].scope = 0;
2119	av_log(matroska->ctx, AV_LOG_ERROR,
2120	"Unsupported encoding type");
2121	} else if (track->codec_priv.size && encodings[0].scope & 2) {
2122	uint8_t *codec_priv = track->codec_priv.data;
2123	int ret = matroska_decode_buffer(&track->codec_priv.data,
2124	&track->codec_priv.size,
2125	track);
2126	if (ret < 0) {
2127	track->codec_priv.data = NULL;
2128	track->codec_priv.size = 0;
2129	av_log(matroska->ctx, AV_LOG_ERROR,
2130	"Failed to decode codec private data\n");
2131	}
2132
2133	if (codec_priv != track->codec_priv.data)
2134	av_free(codec_priv);
2135	}
2136	}
2137
2138	for (j = 0; ff_mkv_codec_tags[j].id != AV_CODEC_ID_NONE; j++) {
2139	if (!strncmp(ff_mkv_codec_tags[j].str, track->codec_id,
2140	strlen(ff_mkv_codec_tags[j].str))) {
2141	codec_id = ff_mkv_codec_tags[j].id;
2142	break;
2143	}
2144	}
2145
2146	st = track->stream = avformat_new_stream(s, NULL);
2147	if (!st) {
2148	av_free(key_id_base64);
2149	return AVERROR(ENOMEM);
2150	}
2151
2152	if (key_id_base64) {
2153	/* export encryption key id as base64 metadata tag */
2154	av_dict_set(&st->metadata, "enc_key_id", key_id_base64, 0);
2155	av_freep(&key_id_base64);
2156	}
2157
2158	if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC") &&
2159	track->codec_priv.size >= 40 &&
2160	track->codec_priv.data) {
2161	track->ms_compat = 1;
2162	bit_depth = AV_RL16(track->codec_priv.data + 14);
2163	fourcc = AV_RL32(track->codec_priv.data + 16);
2164	codec_id = ff_codec_get_id(ff_codec_bmp_tags,
2165	fourcc);
2166	if (!codec_id)
2167	codec_id = ff_codec_get_id(ff_codec_movvideo_tags,
2168	fourcc);
2169	extradata_offset = 40;
2170	} else if (!strcmp(track->codec_id, "A_MS/ACM") &&
2171	track->codec_priv.size >= 14 &&
2172	track->codec_priv.data) {
2173	int ret;
2174	ffio_init_context(&b, track->codec_priv.data,
2175	track->codec_priv.size,
2176	0, NULL, NULL, NULL, NULL);
2177	ret = ff_get_wav_header(s, &b, st->codecpar, track->codec_priv.size, 0);
2178	if (ret < 0)
2179	return ret;
2180	codec_id = st->codecpar->codec_id;
2181	fourcc = st->codecpar->codec_tag;
2182	extradata_offset = FFMIN(track->codec_priv.size, 18);
2183	} else if (!strcmp(track->codec_id, "A_QUICKTIME")
2184	/* Normally 36, but allow noncompliant private data */
2185	&& (track->codec_priv.size >= 32)
2186	&& (track->codec_priv.data)) {
2187	uint16_t sample_size;
2188	int ret = get_qt_codec(track, &fourcc, &codec_id);
2189	if (ret < 0)
2190	return ret;
2191	sample_size = AV_RB16(track->codec_priv.data + 26);
2192	if (fourcc == 0) {
2193	if (sample_size == 8) {
2194	fourcc = MKTAG('r','a','w',' ');
2195	codec_id = ff_codec_get_id(ff_codec_movaudio_tags, fourcc);
2196	} else if (sample_size == 16) {
2197	fourcc = MKTAG('t','w','o','s');
2198	codec_id = ff_codec_get_id(ff_codec_movaudio_tags, fourcc);
2199	}
2200	}
2201	if ((fourcc == MKTAG('t','w','o','s') ||
2202	fourcc == MKTAG('s','o','w','t')) &&
2203	sample_size == 8)
2204	codec_id = AV_CODEC_ID_PCM_S8;
2205	} else if (!strcmp(track->codec_id, "V_QUICKTIME") &&
2206	(track->codec_priv.size >= 21) &&
2207	(track->codec_priv.data)) {
2208	int ret = get_qt_codec(track, &fourcc, &codec_id);
2209	if (ret < 0)
2210	return ret;
2211	if (codec_id == AV_CODEC_ID_NONE && AV_RL32(track->codec_priv.data+4) == AV_RL32("SMI ")) {
2212	fourcc = MKTAG('S','V','Q','3');
2213	codec_id = ff_codec_get_id(ff_codec_movvideo_tags, fourcc);
2214	}
2215	if (codec_id == AV_CODEC_ID_NONE)
2216	av_log(matroska->ctx, AV_LOG_ERROR,
2217	"mov FourCC not found %s.\n", av_fourcc2str(fourcc));
2218	if (track->codec_priv.size >= 86) {
2219	bit_depth = AV_RB16(track->codec_priv.data + 82);
2220	ffio_init_context(&b, track->codec_priv.data,
2221	track->codec_priv.size,
2222	0, NULL, NULL, NULL, NULL);
2223	if (ff_get_qtpalette(codec_id, &b, track->palette)) {
2224	bit_depth &= 0x1F;
2225	track->has_palette = 1;
2226	}
2227	}
2228	} else if (codec_id == AV_CODEC_ID_PCM_S16BE) {
2229	switch (track->audio.bitdepth) {
2230	case 8:
2231	codec_id = AV_CODEC_ID_PCM_U8;
2232	break;
2233	case 24:
2234	codec_id = AV_CODEC_ID_PCM_S24BE;
2235	break;
2236	case 32:
2237	codec_id = AV_CODEC_ID_PCM_S32BE;
2238	break;
2239	}
2240	} else if (codec_id == AV_CODEC_ID_PCM_S16LE) {
2241	switch (track->audio.bitdepth) {
2242	case 8:
2243	codec_id = AV_CODEC_ID_PCM_U8;
2244	break;
2245	case 24:
2246	codec_id = AV_CODEC_ID_PCM_S24LE;
2247	break;
2248	case 32:
2249	codec_id = AV_CODEC_ID_PCM_S32LE;
2250	break;
2251	}
2252	} else if (codec_id == AV_CODEC_ID_PCM_F32LE &&
2253	track->audio.bitdepth == 64) {
2254	codec_id = AV_CODEC_ID_PCM_F64LE;
2255	} else if (codec_id == AV_CODEC_ID_AAC && !track->codec_priv.size) {
2256	int profile = matroska_aac_profile(track->codec_id);
2257	int sri = matroska_aac_sri(track->audio.samplerate);
2258	extradata = av_mallocz(5 + AV_INPUT_BUFFER_PADDING_SIZE);
2259	if (!extradata)
2260	return AVERROR(ENOMEM);
2261	extradata[0] = (profile << 3) | ((sri & 0x0E) >> 1);
2262	extradata[1] = ((sri & 0x01) << 7) | (track->audio.channels << 3);
2263	if (strstr(track->codec_id, "SBR")) {
2264	sri = matroska_aac_sri(track->audio.out_samplerate);
2265	extradata[2] = 0x56;
2266	extradata[3] = 0xE5;
2267	extradata[4] = 0x80 | (sri << 3);
2268	extradata_size = 5;
2269	} else
2270	extradata_size = 2;
2271	} else if (codec_id == AV_CODEC_ID_ALAC && track->codec_priv.size && track->codec_priv.size < INT_MAX - 12 - AV_INPUT_BUFFER_PADDING_SIZE) {
2272	/* Only ALAC's magic cookie is stored in Matroska's track headers.
2273	* Create the "atom size", "tag", and "tag version" fields the
2274	* decoder expects manually. */
2275	extradata_size = 12 + track->codec_priv.size;
2276	extradata = av_mallocz(extradata_size +
2277	AV_INPUT_BUFFER_PADDING_SIZE);
2278	if (!extradata)
2279	return AVERROR(ENOMEM);
2280	AV_WB32(extradata, extradata_size);
2281	memcpy(&extradata[4], "alac", 4);
2282	AV_WB32(&extradata[8], 0);
2283	memcpy(&extradata[12], track->codec_priv.data,
2284	track->codec_priv.size);
2285	} else if (codec_id == AV_CODEC_ID_TTA) {
2286	extradata_size = 30;
2287	extradata = av_mallocz(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
2288	if (!extradata)
2289	return AVERROR(ENOMEM);
2290	ffio_init_context(&b, extradata, extradata_size, 1,
2291	NULL, NULL, NULL, NULL);
2292	avio_write(&b, "TTA1", 4);
2293	avio_wl16(&b, 1);
2294	if (track->audio.channels > UINT16_MAX ||
2295	track->audio.bitdepth > UINT16_MAX) {
2296	av_log(matroska->ctx, AV_LOG_WARNING,
2297	"Too large audio channel number %"PRIu64
2298	" or bitdepth %"PRIu64". Skipping track.\n",
2299	track->audio.channels, track->audio.bitdepth);
2300	av_freep(&extradata);
2301	if (matroska->ctx->error_recognition & AV_EF_EXPLODE)
2302	return AVERROR_INVALIDDATA;
2303	else
2304	continue;
2305	}
2306	avio_wl16(&b, track->audio.channels);
2307	avio_wl16(&b, track->audio.bitdepth);
2308	if (track->audio.out_samplerate < 0 || track->audio.out_samplerate > INT_MAX)
2309	return AVERROR_INVALIDDATA;
2310	avio_wl32(&b, track->audio.out_samplerate);
2311	avio_wl32(&b, av_rescale((matroska->duration * matroska->time_scale),
2312	track->audio.out_samplerate,
2313	AV_TIME_BASE * 1000));
2314	} else if (codec_id == AV_CODEC_ID_RV10 ||
2315	codec_id == AV_CODEC_ID_RV20 ||
2316	codec_id == AV_CODEC_ID_RV30 ||
2317	codec_id == AV_CODEC_ID_RV40) {
2318	extradata_offset = 26;
2319	} else if (codec_id == AV_CODEC_ID_RA_144) {
2320	track->audio.out_samplerate = 8000;
2321	track->audio.channels = 1;
2322	} else if ((codec_id == AV_CODEC_ID_RA_288 ||
2323	codec_id == AV_CODEC_ID_COOK ||
2324	codec_id == AV_CODEC_ID_ATRAC3 ||
2325	codec_id == AV_CODEC_ID_SIPR)
2326	&& track->codec_priv.data) {
2327	int flavor;
2328
2329	ffio_init_context(&b, track->codec_priv.data,
2330	track->codec_priv.size,
2331	0, NULL, NULL, NULL, NULL);
2332	avio_skip(&b, 22);
2333	flavor = avio_rb16(&b);
2334	track->audio.coded_framesize = avio_rb32(&b);
2335	avio_skip(&b, 12);
2336	track->audio.sub_packet_h = avio_rb16(&b);
2337	track->audio.frame_size = avio_rb16(&b);
2338	track->audio.sub_packet_size = avio_rb16(&b);
2339	if (flavor < 0 ||
2340	track->audio.coded_framesize <= 0 ||
2341	track->audio.sub_packet_h <= 0 ||
2342	track->audio.frame_size <= 0 ||
2343	track->audio.sub_packet_size <= 0 && codec_id != AV_CODEC_ID_SIPR)
2344	return AVERROR_INVALIDDATA;
2345	track->audio.buf = av_malloc_array(track->audio.sub_packet_h,
2346	track->audio.frame_size);
2347	if (!track->audio.buf)
2348	return AVERROR(ENOMEM);
2349	if (codec_id == AV_CODEC_ID_RA_288) {
2350	st->codecpar->block_align = track->audio.coded_framesize;
2351	track->codec_priv.size = 0;
2352	} else {
2353	if (codec_id == AV_CODEC_ID_SIPR && flavor < 4) {
2354	static const int sipr_bit_rate[4] = { 6504, 8496, 5000, 16000 };
2355	track->audio.sub_packet_size = ff_sipr_subpk_size[flavor];
2356	st->codecpar->bit_rate = sipr_bit_rate[flavor];
2357	}
2358	st->codecpar->block_align = track->audio.sub_packet_size;
2359	extradata_offset = 78;
2360	}
2361	} else if (codec_id == AV_CODEC_ID_FLAC && track->codec_priv.size) {
2362	ret = matroska_parse_flac(s, track, &extradata_offset);
2363	if (ret < 0)
2364	return ret;
2365	} else if (codec_id == AV_CODEC_ID_PRORES && track->codec_priv.size == 4) {
2366	fourcc = AV_RL32(track->codec_priv.data);
2367	}
2368	track->codec_priv.size -= extradata_offset;
2369
2370	if (codec_id == AV_CODEC_ID_NONE)
2371	av_log(matroska->ctx, AV_LOG_INFO,
2372	"Unknown/unsupported AVCodecID %s.\n", track->codec_id);
2373
2374	if (track->time_scale < 0.01)
2375	track->time_scale = 1.0;
2376	avpriv_set_pts_info(st, 64, matroska->time_scale * track->time_scale,
2377	1000 * 1000 * 1000); /* 64 bit pts in ns */
2378
2379	/* convert the delay from ns to the track timebase */
2380	track->codec_delay_in_track_tb = av_rescale_q(track->codec_delay,
2381	(AVRational){ 1, 1000000000 },
2382	st->time_base);
2383
2384	st->codecpar->codec_id = codec_id;
2385
2386	if (strcmp(track->language, "und"))
2387	av_dict_set(&st->metadata, "language", track->language, 0);
2388	av_dict_set(&st->metadata, "title", track->name, 0);
2389
2390	if (track->flag_default)
2391	st->disposition |= AV_DISPOSITION_DEFAULT;
2392	if (track->flag_forced)
2393	st->disposition |= AV_DISPOSITION_FORCED;
2394
2395	if (!st->codecpar->extradata) {
2396	if (extradata) {
2397	st->codecpar->extradata = extradata;
2398	st->codecpar->extradata_size = extradata_size;
2399	} else if (track->codec_priv.data && track->codec_priv.size > 0) {
2400	if (ff_alloc_extradata(st->codecpar, track->codec_priv.size))
2401	return AVERROR(ENOMEM);
2402	memcpy(st->codecpar->extradata,
2403	track->codec_priv.data + extradata_offset,
2404	track->codec_priv.size);
2405	}
2406	}
2407
2408	if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
2409	MatroskaTrackPlane *planes = track->operation.combine_planes.elem;
2410	int display_width_mul = 1;
2411	int display_height_mul = 1;
2412
2413	st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
2414	st->codecpar->codec_tag = fourcc;
2415	if (bit_depth >= 0)
2416	st->codecpar->bits_per_coded_sample = bit_depth;
2417	st->codecpar->width = track->video.pixel_width;
2418	st->codecpar->height = track->video.pixel_height;
2419
2420	if (track->video.interlaced == MATROSKA_VIDEO_INTERLACE_FLAG_INTERLACED)
2421	st->codecpar->field_order = mkv_field_order(matroska, track->video.field_order);
2422	else if (track->video.interlaced == MATROSKA_VIDEO_INTERLACE_FLAG_PROGRESSIVE)
2423	st->codecpar->field_order = AV_FIELD_PROGRESSIVE;
2424
2425	if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB)
2426	mkv_stereo_mode_display_mul(track->video.stereo_mode, &display_width_mul, &display_height_mul);
2427
2428	if (track->video.display_unit < MATROSKA_VIDEO_DISPLAYUNIT_UNKNOWN) {
2429	av_reduce(&st->sample_aspect_ratio.num,
2430	&st->sample_aspect_ratio.den,
2431	st->codecpar->height * track->video.display_width * display_width_mul,
2432	st->codecpar->width * track->video.display_height * display_height_mul,
2433	255);
2434	}
2435	if (st->codecpar->codec_id != AV_CODEC_ID_HEVC)
2436	st->need_parsing = AVSTREAM_PARSE_HEADERS;
2437
2438	if (track->default_duration) {
2439	av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
2440	1000000000, track->default_duration, 30000);
2441	#if FF_API_R_FRAME_RATE
2442	if ( st->avg_frame_rate.num < st->avg_frame_rate.den * 1000LL
2443	&& st->avg_frame_rate.num > st->avg_frame_rate.den * 5LL)
2444	st->r_frame_rate = st->avg_frame_rate;
2445	#endif
2446	}
2447
2448	/* export stereo mode flag as metadata tag */
2449	if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB)
2450	av_dict_set(&st->metadata, "stereo_mode", ff_matroska_video_stereo_mode[track->video.stereo_mode], 0);
2451
2452	/* export alpha mode flag as metadata tag */
2453	if (track->video.alpha_mode)
2454	av_dict_set(&st->metadata, "alpha_mode", "1", 0);
2455
2456	/* if we have virtual track, mark the real tracks */
2457	for (j=0; j < track->operation.combine_planes.nb_elem; j++) {
2458	char buf[32];
2459	if (planes[j].type >= MATROSKA_VIDEO_STEREO_PLANE_COUNT)
2460	continue;
2461	snprintf(buf, sizeof(buf), "%s_%d",
2462	ff_matroska_video_stereo_plane[planes[j].type], i);
2463	for (k=0; k < matroska->tracks.nb_elem; k++)
2464	if (planes[j].uid == tracks[k].uid && tracks[k].stream) {
2465	av_dict_set(&tracks[k].stream->metadata,
2466	"stereo_mode", buf, 0);
2467	break;
2468	}
2469	}
2470	// add stream level stereo3d side data if it is a supported format
2471	if (track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB &&
2472	track->video.stereo_mode != 10 && track->video.stereo_mode != 12) {
2473	int ret = ff_mkv_stereo3d_conv(st, track->video.stereo_mode);
2474	if (ret < 0)
2475	return ret;
2476	}
2477
2478	ret = mkv_parse_video_color(st, track);
2479	if (ret < 0)
2480	return ret;
2481	ret = mkv_parse_video_projection(st, track);
2482	if (ret < 0)
2483	return ret;
2484	} else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
2485	st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
2486	st->codecpar->codec_tag = fourcc;
2487	st->codecpar->sample_rate = track->audio.out_samplerate;
2488	st->codecpar->channels = track->audio.channels;
2489	if (!st->codecpar->bits_per_coded_sample)
2490	st->codecpar->bits_per_coded_sample = track->audio.bitdepth;
2491	if (st->codecpar->codec_id == AV_CODEC_ID_MP3)
2492	st->need_parsing = AVSTREAM_PARSE_FULL;
2493	else if (st->codecpar->codec_id != AV_CODEC_ID_AAC)
2494	st->need_parsing = AVSTREAM_PARSE_HEADERS;
2495	if (track->codec_delay > 0) {
2496	st->codecpar->initial_padding = av_rescale_q(track->codec_delay,
2497	(AVRational){1, 1000000000},
2498	(AVRational){1, st->codecpar->codec_id == AV_CODEC_ID_OPUS ?
2499	48000 : st->codecpar->sample_rate});
2500	}
2501	if (track->seek_preroll > 0) {
2502	st->codecpar->seek_preroll = av_rescale_q(track->seek_preroll,
2503	(AVRational){1, 1000000000},
2504	(AVRational){1, st->codecpar->sample_rate});
2505	}
2506	} else if (codec_id == AV_CODEC_ID_WEBVTT) {
2507	st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
2508
2509	if (!strcmp(track->codec_id, "D_WEBVTT/CAPTIONS")) {
2510	st->disposition |= AV_DISPOSITION_CAPTIONS;
2511	} else if (!strcmp(track->codec_id, "D_WEBVTT/DESCRIPTIONS")) {
2512	st->disposition |= AV_DISPOSITION_DESCRIPTIONS;
2513	} else if (!strcmp(track->codec_id, "D_WEBVTT/METADATA")) {
2514	st->disposition |= AV_DISPOSITION_METADATA;
2515	}
2516	} else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
2517	st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
2518	if (st->codecpar->codec_id == AV_CODEC_ID_ASS)
2519	matroska->contains_ssa = 1;
2520	}
2521	}
2522
2523	return 0;
2524	}
2525
2526	static int matroska_read_header(AVFormatContext *s)
2527	{
2528	MatroskaDemuxContext *matroska = s->priv_data;
2529	EbmlList *attachments_list = &matroska->attachments;
2530	EbmlList *chapters_list = &matroska->chapters;
2531	MatroskaAttachment *attachments;
2532	MatroskaChapter *chapters;
2533	uint64_t max_start = 0;
2534	int64_t pos;
2535	Ebml ebml = { 0 };
2536	int i, j, res;
2537
2538	matroska->ctx = s;
2539	matroska->cues_parsing_deferred = 1;
2540
2541	/* First read the EBML header. */
2542	if (ebml_parse(matroska, ebml_syntax, &ebml) || !ebml.doctype) {
2543	av_log(matroska->ctx, AV_LOG_ERROR, "EBML header parsing failed\n");
2544	ebml_free(ebml_syntax, &ebml);
2545	return AVERROR_INVALIDDATA;
2546	}
2547	if (ebml.version > EBML_VERSION ||
2548	ebml.max_size > sizeof(uint64_t) ||
2549	ebml.id_length > sizeof(uint32_t) ||
2550	ebml.doctype_version > 3) {
2551	avpriv_report_missing_feature(matroska->ctx,
2552	"EBML version %"PRIu64", doctype %s, doc version %"PRIu64,
2553	ebml.version, ebml.doctype, ebml.doctype_version);
2554	ebml_free(ebml_syntax, &ebml);
2555	return AVERROR_PATCHWELCOME;
2556	} else if (ebml.doctype_version == 3) {
2557	av_log(matroska->ctx, AV_LOG_WARNING,
2558	"EBML header using unsupported features\n"
2559	"(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
2560	ebml.version, ebml.doctype, ebml.doctype_version);
2561	}
2562	for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++)
2563	if (!strcmp(ebml.doctype, matroska_doctypes[i]))
2564	break;
2565	if (i >= FF_ARRAY_ELEMS(matroska_doctypes)) {
2566	av_log(s, AV_LOG_WARNING, "Unknown EBML doctype '%s'\n", ebml.doctype);
2567	if (matroska->ctx->error_recognition & AV_EF_EXPLODE) {
2568	ebml_free(ebml_syntax, &ebml);
2569	return AVERROR_INVALIDDATA;
2570	}
2571	}
2572	ebml_free(ebml_syntax, &ebml);
2573
2574	/* The next thing is a segment. */
2575	pos = avio_tell(matroska->ctx->pb);
2576	res = ebml_parse(matroska, matroska_segments, matroska);
2577	// try resyncing until we find a EBML_STOP type element.
2578	while (res != 1) {
2579	res = matroska_resync(matroska, pos);
2580	if (res < 0)
2581	goto fail;
2582	pos = avio_tell(matroska->ctx->pb);
2583	res = ebml_parse(matroska, matroska_segment, matroska);
2584	}
2585	matroska_execute_seekhead(matroska);
2586
2587	if (!matroska->time_scale)
2588	matroska->time_scale = 1000000;
2589	if (matroska->duration)
2590	matroska->ctx->duration = matroska->duration * matroska->time_scale *
2591	1000 / AV_TIME_BASE;
2592	av_dict_set(&s->metadata, "title", matroska->title, 0);
2593	av_dict_set(&s->metadata, "encoder", matroska->muxingapp, 0);
2594
2595	if (matroska->date_utc.size == 8)
2596	matroska_metadata_creation_time(&s->metadata, AV_RB64(matroska->date_utc.data));
2597
2598	res = matroska_parse_tracks(s);
2599	if (res < 0)
2600	goto fail;
2601
2602	attachments = attachments_list->elem;
2603	for (j = 0; j < attachments_list->nb_elem; j++) {
2604	if (!(attachments[j].filename && attachments[j].mime &&
2605	attachments[j].bin.data && attachments[j].bin.size > 0)) {
2606	av_log(matroska->ctx, AV_LOG_ERROR, "incomplete attachment\n");
2607	} else {
2608	AVStream *st = avformat_new_stream(s, NULL);
2609	if (!st)
2610	break;
2611	av_dict_set(&st->metadata, "filename", attachments[j].filename, 0);
2612	av_dict_set(&st->metadata, "mimetype", attachments[j].mime, 0);
2613	st->codecpar->codec_id = AV_CODEC_ID_NONE;
2614
2615	for (i = 0; ff_mkv_image_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
2616	if (!strncmp(ff_mkv_image_mime_tags[i].str, attachments[j].mime,
2617	strlen(ff_mkv_image_mime_tags[i].str))) {
2618	st->codecpar->codec_id = ff_mkv_image_mime_tags[i].id;
2619	break;
2620	}
2621	}
2622
2623	attachments[j].stream = st;
2624
2625	if (st->codecpar->codec_id != AV_CODEC_ID_NONE) {
2626	st->disposition |= AV_DISPOSITION_ATTACHED_PIC;
2627	st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
2628
2629	av_init_packet(&st->attached_pic);
2630	if ((res = av_new_packet(&st->attached_pic, attachments[j].bin.size)) < 0)
2631	return res;
2632	memcpy(st->attached_pic.data, attachments[j].bin.data, attachments[j].bin.size);
2633	st->attached_pic.stream_index = st->index;
2634	st->attached_pic.flags |= AV_PKT_FLAG_KEY;
2635	} else {
2636	st->codecpar->codec_type = AVMEDIA_TYPE_ATTACHMENT;
2637	if (ff_alloc_extradata(st->codecpar, attachments[j].bin.size))
2638	break;
2639	memcpy(st->codecpar->extradata, attachments[j].bin.data,
2640	attachments[j].bin.size);
2641
2642	for (i = 0; ff_mkv_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
2643	if (!strncmp(ff_mkv_mime_tags[i].str, attachments[j].mime,
2644	strlen(ff_mkv_mime_tags[i].str))) {
2645	st->codecpar->codec_id = ff_mkv_mime_tags[i].id;
2646	break;
2647	}
2648	}
2649	}
2650	}
2651	}
2652
2653	chapters = chapters_list->elem;
2654	for (i = 0; i < chapters_list->nb_elem; i++)
2655	if (chapters[i].start != AV_NOPTS_VALUE && chapters[i].uid &&
2656	(max_start == 0 || chapters[i].start > max_start)) {
2657	chapters[i].chapter =
2658	avpriv_new_chapter(s, chapters[i].uid,
2659	(AVRational) { 1, 1000000000 },
2660	chapters[i].start, chapters[i].end,
2661	chapters[i].title);
2662	if (chapters[i].chapter) {
2663	av_dict_set(&chapters[i].chapter->metadata,
2664	"title", chapters[i].title, 0);
2665	}
2666	max_start = chapters[i].start;
2667	}
2668
2669	matroska_add_index_entries(matroska);
2670
2671	matroska_convert_tags(s);
2672
2673	return 0;
2674	fail:
2675	matroska_read_close(s);
2676	return res;
2677	}
2678
2679	/*
2680	* Put one packet in an application-supplied AVPacket struct.
2681	* Returns 0 on success or -1 on failure.
2682	*/
2683	static int matroska_deliver_packet(MatroskaDemuxContext *matroska,
2684	AVPacket *pkt)
2685	{
2686	if (matroska->num_packets > 0) {
2687	MatroskaTrack *tracks = matroska->tracks.elem;
2688	MatroskaTrack *track;
2689	memcpy(pkt, matroska->packets[0], sizeof(AVPacket));
2690	av_freep(&matroska->packets[0]);
2691	track = &tracks[pkt->stream_index];
2692	if (track->has_palette) {
2693	uint8_t *pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, AVPALETTE_SIZE);
2694	if (!pal) {
2695	av_log(matroska->ctx, AV_LOG_ERROR, "Cannot append palette to packet\n");
2696	} else {
2697	memcpy(pal, track->palette, AVPALETTE_SIZE);
2698	}
2699	track->has_palette = 0;
2700	}
2701	if (matroska->num_packets > 1) {
2702	void *newpackets;
2703	memmove(&matroska->packets[0], &matroska->packets[1],
2704	(matroska->num_packets - 1) * sizeof(AVPacket *));
2705	newpackets = av_realloc(matroska->packets,
2706	(matroska->num_packets - 1) *
2707	sizeof(AVPacket *));
2708	if (newpackets)
2709	matroska->packets = newpackets;
2710	} else {
2711	av_freep(&matroska->packets);
2712	matroska->prev_pkt = NULL;
2713	}
2714	matroska->num_packets--;
2715	return 0;
2716	}
2717
2718	return -1;
2719	}
2720
2721	/*
2722	* Free all packets in our internal queue.
2723	*/
2724	static void matroska_clear_queue(MatroskaDemuxContext *matroska)
2725	{
2726	matroska->prev_pkt = NULL;
2727	if (matroska->packets) {
2728	int n;
2729	for (n = 0; n < matroska->num_packets; n++) {
2730	av_packet_unref(matroska->packets[n]);
2731	av_freep(&matroska->packets[n]);
2732	}
2733	av_freep(&matroska->packets);
2734	matroska->num_packets = 0;
2735	}
2736	}
2737
2738	static int matroska_parse_laces(MatroskaDemuxContext *matroska, uint8_t **buf,
2739	int *buf_size, int type,
2740	uint32_t **lace_buf, int *laces)
2741	{
2742	int res = 0, n, size = *buf_size;
2743	uint8_t *data = *buf;
2744	uint32_t *lace_size;
2745
2746	if (!type) {
2747	*laces = 1;
2748	*lace_buf = av_mallocz(sizeof(int));
2749	if (!*lace_buf)
2750	return AVERROR(ENOMEM);
2751
2752	*lace_buf[0] = size;
2753	return 0;
2754	}
2755
2756	av_assert0(size > 0);
2757	*laces = *data + 1;
2758	data += 1;
2759	size -= 1;
2760	lace_size = av_mallocz(*laces * sizeof(int));
2761	if (!lace_size)
2762	return AVERROR(ENOMEM);
2763
2764	switch (type) {
2765	case 0x1: /* Xiph lacing */
2766	{
2767	uint8_t temp;
2768	uint32_t total = 0;
2769	for (n = 0; res == 0 && n < *laces - 1; n++) {
2770	while (1) {
2771	if (size <= total) {
2772	res = AVERROR_INVALIDDATA;
2773	break;
2774	}
2775	temp = *data;
2776	total += temp;
2777	lace_size[n] += temp;
2778	data += 1;
2779	size -= 1;
2780	if (temp != 0xff)
2781	break;
2782	}
2783	}
2784	if (size <= total) {
2785	res = AVERROR_INVALIDDATA;
2786	break;
2787	}
2788
2789	lace_size[n] = size - total;
2790	break;
2791	}
2792
2793	case 0x2: /* fixed-size lacing */
2794	if (size % (*laces)) {
2795	res = AVERROR_INVALIDDATA;
2796	break;
2797	}
2798	for (n = 0; n < *laces; n++)
2799	lace_size[n] = size / *laces;
2800	break;
2801
2802	case 0x3: /* EBML lacing */
2803	{
2804	uint64_t num;
2805	uint64_t total;
2806	n = matroska_ebmlnum_uint(matroska, data, size, &num);
2807	if (n < 0 || num > INT_MAX) {
2808	av_log(matroska->ctx, AV_LOG_INFO,
2809	"EBML block data error\n");
2810	res = n<0 ? n : AVERROR_INVALIDDATA;
2811	break;
2812	}
2813	data += n;
2814	size -= n;
2815	total = lace_size[0] = num;
2816	for (n = 1; res == 0 && n < *laces - 1; n++) {
2817	int64_t snum;
2818	int r;
2819	r = matroska_ebmlnum_sint(matroska, data, size, &snum);
2820	if (r < 0 || lace_size[n - 1] + snum > (uint64_t)INT_MAX) {
2821	av_log(matroska->ctx, AV_LOG_INFO,
2822	"EBML block data error\n");
2823	res = r<0 ? r : AVERROR_INVALIDDATA;
2824	break;
2825	}
2826	data += r;
2827	size -= r;
2828	lace_size[n] = lace_size[n - 1] + snum;
2829	total += lace_size[n];
2830	}
2831	if (size <= total) {
2832	res = AVERROR_INVALIDDATA;
2833	break;
2834	}
2835	lace_size[*laces - 1] = size - total;
2836	break;
2837	}
2838	}
2839
2840	*buf = data;
2841	*lace_buf = lace_size;
2842	*buf_size = size;
2843
2844	return res;
2845	}
2846
2847	static int matroska_parse_rm_audio(MatroskaDemuxContext *matroska,
2848	MatroskaTrack *track, AVStream *st,
2849	uint8_t *data, int size, uint64_t timecode,
2850	int64_t pos)
2851	{
2852	int a = st->codecpar->block_align;
2853	int sps = track->audio.sub_packet_size;
2854	int cfs = track->audio.coded_framesize;
2855	int h = track->audio.sub_packet_h;
2856	int y = track->audio.sub_packet_cnt;
2857	int w = track->audio.frame_size;
2858	int x;
2859
2860	if (!track->audio.pkt_cnt) {
2861	if (track->audio.sub_packet_cnt == 0)
2862	track->audio.buf_timecode = timecode;
2863	if (st->codecpar->codec_id == AV_CODEC_ID_RA_288) {
2864	if (size < cfs * h / 2) {
2865	av_log(matroska->ctx, AV_LOG_ERROR,
2866	"Corrupt int4 RM-style audio packet size\n");
2867	return AVERROR_INVALIDDATA;
2868	}
2869	for (x = 0; x < h / 2; x++)
2870	memcpy(track->audio.buf + x * 2 * w + y * cfs,
2871	data + x * cfs, cfs);
2872	} else if (st->codecpar->codec_id == AV_CODEC_ID_SIPR) {
2873	if (size < w) {
2874	av_log(matroska->ctx, AV_LOG_ERROR,
2875	"Corrupt sipr RM-style audio packet size\n");
2876	return AVERROR_INVALIDDATA;
2877	}
2878	memcpy(track->audio.buf + y * w, data, w);
2879	} else {
2880	if (size < sps * w / sps || h<=0 || w%sps) {
2881	av_log(matroska->ctx, AV_LOG_ERROR,
2882	"Corrupt generic RM-style audio packet size\n");
2883	return AVERROR_INVALIDDATA;
2884	}
2885	for (x = 0; x < w / sps; x++)
2886	memcpy(track->audio.buf +
2887	sps * (h * x + ((h + 1) / 2) * (y & 1) + (y >> 1)),
2888	data + x * sps, sps);
2889	}
2890
2891	if (++track->audio.sub_packet_cnt >= h) {
2892	if (st->codecpar->codec_id == AV_CODEC_ID_SIPR)
2893	ff_rm_reorder_sipr_data(track->audio.buf, h, w);
2894	track->audio.sub_packet_cnt = 0;
2895	track->audio.pkt_cnt = h * w / a;
2896	}
2897	}
2898
2899	while (track->audio.pkt_cnt) {
2900	int ret;
2901	AVPacket *pkt = av_mallocz(sizeof(AVPacket));
2902	if (!pkt)
2903	return AVERROR(ENOMEM);
2904
2905	ret = av_new_packet(pkt, a);
2906	if (ret < 0) {
2907	av_free(pkt);
2908	return ret;
2909	}
2910	memcpy(pkt->data,
2911	track->audio.buf + a * (h * w / a - track->audio.pkt_cnt--),
2912	a);
2913	pkt->pts = track->audio.buf_timecode;
2914	track->audio.buf_timecode = AV_NOPTS_VALUE;
2915	pkt->pos = pos;
2916	pkt->stream_index = st->index;
2917	dynarray_add(&matroska->packets, &matroska->num_packets, pkt);
2918	}
2919
2920	return 0;
2921	}
2922
2923	/* reconstruct full wavpack blocks from mangled matroska ones */
2924	static int matroska_parse_wavpack(MatroskaTrack *track, uint8_t *src,
2925	uint8_t **pdst, int *size)
2926	{
2927	uint8_t *dst = NULL;
2928	int dstlen = 0;
2929	int srclen = *size;
2930	uint32_t samples;
2931	uint16_t ver;
2932	int ret, offset = 0;
2933
2934	if (srclen < 12 || track->stream->codecpar->extradata_size < 2)
2935	return AVERROR_INVALIDDATA;
2936
2937	ver = AV_RL16(track->stream->codecpar->extradata);
2938
2939	samples = AV_RL32(src);
2940	src += 4;
2941	srclen -= 4;
2942
2943	while (srclen >= 8) {
2944	int multiblock;
2945	uint32_t blocksize;
2946	uint8_t *tmp;
2947
2948	uint32_t flags = AV_RL32(src);
2949	uint32_t crc = AV_RL32(src + 4);
2950	src += 8;
2951	srclen -= 8;
2952
2953	multiblock = (flags & 0x1800) != 0x1800;
2954	if (multiblock) {
2955	if (srclen < 4) {
2956	ret = AVERROR_INVALIDDATA;
2957	goto fail;
2958	}
2959	blocksize = AV_RL32(src);
2960	src += 4;
2961	srclen -= 4;
2962	} else
2963	blocksize = srclen;
2964
2965	if (blocksize > srclen) {
2966	ret = AVERROR_INVALIDDATA;
2967	goto fail;
2968	}
2969
2970	tmp = av_realloc(dst, dstlen + blocksize + 32);
2971	if (!tmp) {
2972	ret = AVERROR(ENOMEM);
2973	goto fail;
2974	}
2975	dst = tmp;
2976	dstlen += blocksize + 32;
2977
2978	AV_WL32(dst + offset, MKTAG('w', 'v', 'p', 'k')); // tag
2979	AV_WL32(dst + offset + 4, blocksize + 24); // blocksize - 8
2980	AV_WL16(dst + offset + 8, ver); // version
2981	AV_WL16(dst + offset + 10, 0); // track/index_no
2982	AV_WL32(dst + offset + 12, 0); // total samples
2983	AV_WL32(dst + offset + 16, 0); // block index
2984	AV_WL32(dst + offset + 20, samples); // number of samples
2985	AV_WL32(dst + offset + 24, flags); // flags
2986	AV_WL32(dst + offset + 28, crc); // crc
2987	memcpy(dst + offset + 32, src, blocksize); // block data
2988
2989	src += blocksize;
2990	srclen -= blocksize;
2991	offset += blocksize + 32;
2992	}
2993
2994	*pdst = dst;
2995	*size = dstlen;
2996
2997	return 0;
2998
2999	fail:
3000	av_freep(&dst);
3001	return ret;
3002	}
3003
3004	static int matroska_parse_webvtt(MatroskaDemuxContext *matroska,
3005	MatroskaTrack *track,
3006	AVStream *st,
3007	uint8_t *data, int data_len,
3008	uint64_t timecode,
3009	uint64_t duration,
3010	int64_t pos)
3011	{
3012	AVPacket *pkt;
3013	uint8_t *id, *settings, *text, *buf;
3014	int id_len, settings_len, text_len;
3015	uint8_t *p, *q;
3016	int err;
3017
3018	if (data_len <= 0)
3019	return AVERROR_INVALIDDATA;
3020
3021	p = data;
3022	q = data + data_len;
3023
3024	id = p;
3025	id_len = -1;
3026	while (p < q) {
3027	if (*p == '\r' || *p == '\n') {
3028	id_len = p - id;
3029	if (*p == '\r')
3030	p++;
3031	break;
3032	}
3033	p++;
3034	}
3035
3036	if (p >= q || *p != '\n')
3037	return AVERROR_INVALIDDATA;
3038	p++;
3039
3040	settings = p;
3041	settings_len = -1;
3042	while (p < q) {
3043	if (*p == '\r' || *p == '\n') {
3044	settings_len = p - settings;
3045	if (*p == '\r')
3046	p++;
3047	break;
3048	}
3049	p++;
3050	}
3051
3052	if (p >= q || *p != '\n')
3053	return AVERROR_INVALIDDATA;
3054	p++;
3055
3056	text = p;
3057	text_len = q - p;
3058	while (text_len > 0) {
3059	const int len = text_len - 1;
3060	const uint8_t c = p[len];
3061	if (c != '\r' && c != '\n')
3062	break;
3063	text_len = len;
3064	}
3065
3066	if (text_len <= 0)
3067	return AVERROR_INVALIDDATA;
3068
3069	pkt = av_mallocz(sizeof(*pkt));
3070	if (!pkt)
3071	return AVERROR(ENOMEM);
3072	err = av_new_packet(pkt, text_len);
3073	if (err < 0) {
3074	av_free(pkt);
3075	return AVERROR(err);
3076	}
3077
3078	memcpy(pkt->data, text, text_len);
3079
3080	if (id_len > 0) {
3081	buf = av_packet_new_side_data(pkt,
3082	AV_PKT_DATA_WEBVTT_IDENTIFIER,
3083	id_len);
3084	if (!buf) {
3085	av_free(pkt);
3086	return AVERROR(ENOMEM);
3087	}
3088	memcpy(buf, id, id_len);
3089	}
3090
3091	if (settings_len > 0) {
3092	buf = av_packet_new_side_data(pkt,
3093	AV_PKT_DATA_WEBVTT_SETTINGS,
3094	settings_len);
3095	if (!buf) {
3096	av_free(pkt);
3097	return AVERROR(ENOMEM);
3098	}
3099	memcpy(buf, settings, settings_len);
3100	}
3101
3102	// Do we need this for subtitles?
3103	// pkt->flags = AV_PKT_FLAG_KEY;
3104
3105	pkt->stream_index = st->index;
3106	pkt->pts = timecode;
3107
3108	// Do we need this for subtitles?
3109	// pkt->dts = timecode;
3110
3111	pkt->duration = duration;
3112	pkt->pos = pos;
3113
3114	dynarray_add(&matroska->packets, &matroska->num_packets, pkt);
3115	matroska->prev_pkt = pkt;
3116
3117	return 0;
3118	}
3119
3120	static int matroska_parse_frame(MatroskaDemuxContext *matroska,
3121	MatroskaTrack *track, AVStream *st,
3122	uint8_t *data, int pkt_size,
3123	uint64_t timecode, uint64_t lace_duration,
3124	int64_t pos, int is_keyframe,
3125	uint8_t *additional, uint64_t additional_id, int additional_size,
3126	int64_t discard_padding)
3127	{
3128	MatroskaTrackEncoding *encodings = track->encodings.elem;
3129	uint8_t *pkt_data = data;
3130	int offset = 0, res;
3131	AVPacket *pkt;
3132
3133	if (encodings && !encodings->type && encodings->scope & 1) {
3134	res = matroska_decode_buffer(&pkt_data, &pkt_size, track);
3135	if (res < 0)
3136	return res;
3137	}
3138
3139	if (st->codecpar->codec_id == AV_CODEC_ID_WAVPACK) {
3140	uint8_t *wv_data;
3141	res = matroska_parse_wavpack(track, pkt_data, &wv_data, &pkt_size);
3142	if (res < 0) {
3143	av_log(matroska->ctx, AV_LOG_ERROR,
3144	"Error parsing a wavpack block.\n");
3145	goto fail;
3146	}
3147	if (pkt_data != data)
3148	av_freep(&pkt_data);
3149	pkt_data = wv_data;
3150	}
3151
3152	if (st->codecpar->codec_id == AV_CODEC_ID_PRORES &&
3153	AV_RB32(&data[4]) != MKBETAG('i', 'c', 'p', 'f'))
3154	offset = 8;
3155
3156	pkt = av_mallocz(sizeof(AVPacket));
3157	if (!pkt) {
3158	if (pkt_data != data)
3159	av_freep(&pkt_data);
3160	return AVERROR(ENOMEM);
3161	}
3162	/* XXX: prevent data copy... */
3163	if (av_new_packet(pkt, pkt_size + offset) < 0) {
3164	av_free(pkt);
3165	res = AVERROR(ENOMEM);
3166	goto fail;
3167	}
3168
3169	if (st->codecpar->codec_id == AV_CODEC_ID_PRORES && offset == 8) {
3170	uint8_t *buf = pkt->data;
3171	bytestream_put_be32(&buf, pkt_size);
3172	bytestream_put_be32(&buf, MKBETAG('i', 'c', 'p', 'f'));
3173	}
3174
3175	memcpy(pkt->data + offset, pkt_data, pkt_size);
3176
3177	if (pkt_data != data)
3178	av_freep(&pkt_data);
3179
3180	pkt->flags = is_keyframe;
3181	pkt->stream_index = st->index;
3182
3183	if (additional_size > 0) {
3184	uint8_t *side_data = av_packet_new_side_data(pkt,
3185	AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
3186	additional_size + 8);
3187	if (!side_data) {
3188	av_packet_unref(pkt);
3189	av_free(pkt);
3190	return AVERROR(ENOMEM);
3191	}
3192	AV_WB64(side_data, additional_id);
3193	memcpy(side_data + 8, additional, additional_size);
3194	}
3195
3196	if (discard_padding) {
3197	uint8_t *side_data = av_packet_new_side_data(pkt,
3198	AV_PKT_DATA_SKIP_SAMPLES,
3199	10);
3200	if (!side_data) {
3201	av_packet_unref(pkt);
3202	av_free(pkt);
3203	return AVERROR(ENOMEM);
3204	}
3205	discard_padding = av_rescale_q(discard_padding,
3206	(AVRational){1, 1000000000},
3207	(AVRational){1, st->codecpar->sample_rate});
3208	if (discard_padding > 0) {
3209	AV_WL32(side_data + 4, discard_padding);
3210	} else {
3211	AV_WL32(side_data, -discard_padding);
3212	}
3213	}
3214
3215	if (track->ms_compat)
3216	pkt->dts = timecode;
3217	else
3218	pkt->pts = timecode;
3219	pkt->pos = pos;
3220	pkt->duration = lace_duration;
3221
3222	#if FF_API_CONVERGENCE_DURATION
3223	FF_DISABLE_DEPRECATION_WARNINGS
3224	if (st->codecpar->codec_id == AV_CODEC_ID_SUBRIP) {
3225	pkt->convergence_duration = lace_duration;
3226	}
3227	FF_ENABLE_DEPRECATION_WARNINGS
3228	#endif
3229
3230	dynarray_add(&matroska->packets, &matroska->num_packets, pkt);
3231	matroska->prev_pkt = pkt;
3232
3233	return 0;
3234
3235	fail:
3236	if (pkt_data != data)
3237	av_freep(&pkt_data);
3238	return res;
3239	}
3240
3241	static int matroska_parse_block(MatroskaDemuxContext *matroska, uint8_t *data,
3242	int size, int64_t pos, uint64_t cluster_time,
3243	uint64_t block_duration, int is_keyframe,
3244	uint8_t *additional, uint64_t additional_id, int additional_size,
3245	int64_t cluster_pos, int64_t discard_padding)
3246	{
3247	uint64_t timecode = AV_NOPTS_VALUE;
3248	MatroskaTrack *track;
3249	int res = 0;
3250	AVStream *st;
3251	int16_t block_time;
3252	uint32_t *lace_size = NULL;
3253	int n, flags, laces = 0;
3254	uint64_t num;
3255	int trust_default_duration = 1;
3256
3257	if ((n = matroska_ebmlnum_uint(matroska, data, size, &num)) < 0) {
3258	av_log(matroska->ctx, AV_LOG_ERROR, "EBML block data error\n");
3259	return n;
3260	}
3261	data += n;
3262	size -= n;
3263
3264	track = matroska_find_track_by_num(matroska, num);
3265	if (!track || !track->stream) {
3266	av_log(matroska->ctx, AV_LOG_INFO,
3267	"Invalid stream %"PRIu64" or size %u\n", num, size);
3268	return AVERROR_INVALIDDATA;
3269	} else if (size <= 3)
3270	return 0;
3271	st = track->stream;
3272	if (st->discard >= AVDISCARD_ALL)
3273	return res;
3274	av_assert1(block_duration != AV_NOPTS_VALUE);
3275
3276	block_time = sign_extend(AV_RB16(data), 16);
3277	data += 2;
3278	flags = *data++;
3279	size -= 3;
3280	if (is_keyframe == -1)
3281	is_keyframe = flags & 0x80 ? AV_PKT_FLAG_KEY : 0;
3282
3283	if (cluster_time != (uint64_t) -1 &&
3284	(block_time >= 0 || cluster_time >= -block_time)) {
3285	timecode = cluster_time + block_time - track->codec_delay_in_track_tb;
3286	if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE &&
3287	timecode < track->end_timecode)
3288	is_keyframe = 0; /* overlapping subtitles are not key frame */
3289	if (is_keyframe) {
3290	ff_reduce_index(matroska->ctx, st->index);
3291	av_add_index_entry(st, cluster_pos, timecode, 0, 0,
3292	AVINDEX_KEYFRAME);
3293	}
3294	}
3295
3296	if (matroska->skip_to_keyframe &&
3297	track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
3298	// Compare signed timecodes. Timecode may be negative due to codec delay
3299	// offset. We don't support timestamps greater than int64_t anyway - see
3300	// AVPacket's pts.
3301	if ((int64_t)timecode < (int64_t)matroska->skip_to_timecode)
3302	return res;
3303	if (is_keyframe)
3304	matroska->skip_to_keyframe = 0;
3305	else if (!st->skip_to_keyframe) {
3306	av_log(matroska->ctx, AV_LOG_ERROR, "File is broken, keyframes not correctly marked!\n");
3307	matroska->skip_to_keyframe = 0;
3308	}
3309	}
3310
3311	res = matroska_parse_laces(matroska, &data, &size, (flags & 0x06) >> 1,
3312	&lace_size, &laces);
3313
3314	if (res)
3315	goto end;
3316
3317	if (track->audio.samplerate == 8000) {
3318	// If this is needed for more codecs, then add them here
3319	if (st->codecpar->codec_id == AV_CODEC_ID_AC3) {
3320	if (track->audio.samplerate != st->codecpar->sample_rate || !st->codecpar->frame_size)
3321	trust_default_duration = 0;
3322	}
3323	}
3324
3325	if (!block_duration && trust_default_duration)
3326	block_duration = track->default_duration * laces / matroska->time_scale;
3327
3328	if (cluster_time != (uint64_t)-1 && (block_time >= 0 || cluster_time >= -block_time))
3329	track->end_timecode =
3330	FFMAX(track->end_timecode, timecode + block_duration);
3331
3332	for (n = 0; n < laces; n++) {
3333	int64_t lace_duration = block_duration*(n+1) / laces - block_duration*n / laces;
3334
3335	if (lace_size[n] > size) {
3336	av_log(matroska->ctx, AV_LOG_ERROR, "Invalid packet size\n");
3337	break;
3338	}
3339
3340	if ((st->codecpar->codec_id == AV_CODEC_ID_RA_288 ||
3341	st->codecpar->codec_id == AV_CODEC_ID_COOK ||
3342	st->codecpar->codec_id == AV_CODEC_ID_SIPR ||
3343	st->codecpar->codec_id == AV_CODEC_ID_ATRAC3) &&
3344	st->codecpar->block_align && track->audio.sub_packet_size) {
3345	res = matroska_parse_rm_audio(matroska, track, st, data,
3346	lace_size[n],
3347	timecode, pos);
3348	if (res)
3349	goto end;
3350
3351	} else if (st->codecpar->codec_id == AV_CODEC_ID_WEBVTT) {
3352	res = matroska_parse_webvtt(matroska, track, st,
3353	data, lace_size[n],
3354	timecode, lace_duration,
3355	pos);
3356	if (res)
3357	goto end;
3358	} else {
3359	res = matroska_parse_frame(matroska, track, st, data, lace_size[n],
3360	timecode, lace_duration, pos,
3361	!n ? is_keyframe : 0,
3362	additional, additional_id, additional_size,
3363	discard_padding);
3364	if (res)
3365	goto end;
3366	}
3367
3368	if (timecode != AV_NOPTS_VALUE)
3369	timecode = lace_duration ? timecode + lace_duration : AV_NOPTS_VALUE;
3370	data += lace_size[n];
3371	size -= lace_size[n];
3372	}
3373
3374	end:
3375	av_free(lace_size);
3376	return res;
3377	}
3378
3379	static int matroska_parse_cluster_incremental(MatroskaDemuxContext *matroska)
3380	{
3381	EbmlList *blocks_list;
3382	MatroskaBlock *blocks;
3383	int i, res;
3384	res = ebml_parse(matroska,
3385	matroska_cluster_incremental_parsing,
3386	&matroska->current_cluster);
3387	if (res == 1) {
3388	/* New Cluster */
3389	if (matroska->current_cluster_pos)
3390	ebml_level_end(matroska);
3391	ebml_free(matroska_cluster, &matroska->current_cluster);
3392	memset(&matroska->current_cluster, 0, sizeof(MatroskaCluster));
3393	matroska->current_cluster_num_blocks = 0;
3394	matroska->current_cluster_pos = avio_tell(matroska->ctx->pb);
3395	matroska->prev_pkt = NULL;
3396	/* sizeof the ID which was already read */
3397	if (matroska->current_id)
3398	matroska->current_cluster_pos -= 4;
3399	res = ebml_parse(matroska,
3400	matroska_clusters_incremental,
3401	&matroska->current_cluster);
3402	/* Try parsing the block again. */
3403	if (res == 1)
3404	res = ebml_parse(matroska,
3405	matroska_cluster_incremental_parsing,
3406	&matroska->current_cluster);
3407	}
3408
3409	if (!res &&
3410	matroska->current_cluster_num_blocks <
3411	matroska->current_cluster.blocks.nb_elem) {
3412	blocks_list = &matroska->current_cluster.blocks;
3413	blocks = blocks_list->elem;
3414
3415	matroska->current_cluster_num_blocks = blocks_list->nb_elem;
3416	i = blocks_list->nb_elem - 1;
3417	if (blocks[i].bin.size > 0 && blocks[i].bin.data) {
3418	int is_keyframe = blocks[i].non_simple ? blocks[i].reference == INT64_MIN : -1;
3419	uint8_t* additional = blocks[i].additional.size > 0 ?
3420	blocks[i].additional.data : NULL;
3421	if (!blocks[i].non_simple)
3422	blocks[i].duration = 0;
3423	res = matroska_parse_block(matroska, blocks[i].bin.data,
3424	blocks[i].bin.size, blocks[i].bin.pos,
3425	matroska->current_cluster.timecode,
3426	blocks[i].duration, is_keyframe,
3427	additional, blocks[i].additional_id,
3428	blocks[i].additional.size,
3429	matroska->current_cluster_pos,
3430	blocks[i].discard_padding);
3431	}
3432	}
3433
3434	return res;
3435	}
3436
3437	static int matroska_parse_cluster(MatroskaDemuxContext *matroska)
3438	{
3439	MatroskaCluster cluster = { 0 };
3440	EbmlList *blocks_list;
3441	MatroskaBlock *blocks;
3442	int i, res;
3443	int64_t pos;
3444
3445	if (!matroska->contains_ssa)
3446	return matroska_parse_cluster_incremental(matroska);
3447	pos = avio_tell(matroska->ctx->pb);
3448	matroska->prev_pkt = NULL;
3449	if (matroska->current_id)
3450	pos -= 4; /* sizeof the ID which was already read */
3451	res = ebml_parse(matroska, matroska_clusters, &cluster);
3452	blocks_list = &cluster.blocks;
3453	blocks = blocks_list->elem;
3454	for (i = 0; i < blocks_list->nb_elem; i++)
3455	if (blocks[i].bin.size > 0 && blocks[i].bin.data) {
3456	int is_keyframe = blocks[i].non_simple ? blocks[i].reference == INT64_MIN : -1;
3457	res = matroska_parse_block(matroska, blocks[i].bin.data,
3458	blocks[i].bin.size, blocks[i].bin.pos,
3459	cluster.timecode, blocks[i].duration,
3460	is_keyframe, NULL, 0, 0, pos,
3461	blocks[i].discard_padding);
3462	}
3463	ebml_free(matroska_cluster, &cluster);
3464	return res;
3465	}
3466
3467	static int matroska_read_packet(AVFormatContext *s, AVPacket *pkt)
3468	{
3469	MatroskaDemuxContext *matroska = s->priv_data;
3470	int ret = 0;
3471
3472	while (matroska_deliver_packet(matroska, pkt)) {
3473	int64_t pos = avio_tell(matroska->ctx->pb);
3474	if (matroska->done)
3475	return (ret < 0) ? ret : AVERROR_EOF;
3476	if (matroska_parse_cluster(matroska) < 0)
3477	ret = matroska_resync(matroska, pos);
3478	}
3479
3480	return ret;
3481	}
3482
3483	static int matroska_read_seek(AVFormatContext *s, int stream_index,
3484	int64_t timestamp, int flags)
3485	{
3486	MatroskaDemuxContext *matroska = s->priv_data;
3487	MatroskaTrack *tracks = NULL;
3488	AVStream *st = s->streams[stream_index];
3489	int i, index, index_min;
3490
3491	/* Parse the CUES now since we need the index data to seek. */
3492	if (matroska->cues_parsing_deferred > 0) {
3493	matroska->cues_parsing_deferred = 0;
3494	matroska_parse_cues(matroska);
3495	}
3496
3497	if (!st->nb_index_entries)
3498	goto err;
3499	timestamp = FFMAX(timestamp, st->index_entries[0].timestamp);
3500
3501	if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->nb_index_entries - 1) {
3502	avio_seek(s->pb, st->index_entries[st->nb_index_entries - 1].pos,
3503	SEEK_SET);
3504	matroska->current_id = 0;
3505	while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->nb_index_entries - 1) {
3506	matroska_clear_queue(matroska);
3507	if (matroska_parse_cluster(matroska) < 0)
3508	break;
3509	}
3510	}
3511
3512	matroska_clear_queue(matroska);
3513	if (index < 0 || (matroska->cues_parsing_deferred < 0 && index == st->nb_index_entries - 1))
3514	goto err;
3515
3516	index_min = index;
3517	tracks = matroska->tracks.elem;
3518	for (i = 0; i < matroska->tracks.nb_elem; i++) {
3519	tracks[i].audio.pkt_cnt = 0;
3520	tracks[i].audio.sub_packet_cnt = 0;
3521	tracks[i].audio.buf_timecode = AV_NOPTS_VALUE;
3522	tracks[i].end_timecode = 0;
3523	}
3524
3525	avio_seek(s->pb, st->index_entries[index_min].pos, SEEK_SET);
3526	matroska->current_id = 0;
3527	if (flags & AVSEEK_FLAG_ANY) {
3528	st->skip_to_keyframe = 0;
3529	matroska->skip_to_timecode = timestamp;
3530	} else {
3531	st->skip_to_keyframe = 1;
3532	matroska->skip_to_timecode = st->index_entries[index].timestamp;
3533	}
3534	matroska->skip_to_keyframe = 1;
3535	matroska->done = 0;
3536	matroska->num_levels = 0;
3537	ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
3538	return 0;
3539	err:
3540	// slightly hackish but allows proper fallback to
3541	// the generic seeking code.
3542	matroska_clear_queue(matroska);
3543	matroska->current_id = 0;
3544	st->skip_to_keyframe =
3545	matroska->skip_to_keyframe = 0;
3546	matroska->done = 0;
3547	matroska->num_levels = 0;
3548	return -1;
3549	}
3550
3551	static int matroska_read_close(AVFormatContext *s)
3552	{
3553	MatroskaDemuxContext *matroska = s->priv_data;
3554	MatroskaTrack *tracks = matroska->tracks.elem;
3555	int n;
3556
3557	matroska_clear_queue(matroska);
3558
3559	for (n = 0; n < matroska->tracks.nb_elem; n++)
3560	if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)
3561	av_freep(&tracks[n].audio.buf);
3562	ebml_free(matroska_cluster, &matroska->current_cluster);
3563	ebml_free(matroska_segment, matroska);
3564
3565	return 0;
3566	}
3567
3568	typedef struct {
3569	int64_t start_time_ns;
3570	int64_t end_time_ns;
3571	int64_t start_offset;
3572	int64_t end_offset;
3573	} CueDesc;
3574
3575	/* This function searches all the Cues and returns the CueDesc corresponding the
3576	* the timestamp ts. Returned CueDesc will be such that start_time_ns <= ts <
3577	* end_time_ns. All 4 fields will be set to -1 if ts >= file's duration.
3578	*/
3579	static CueDesc get_cue_desc(AVFormatContext *s, int64_t ts, int64_t cues_start) {
3580	MatroskaDemuxContext *matroska = s->priv_data;
3581	CueDesc cue_desc;
3582	int i;
3583	int nb_index_entries = s->streams[0]->nb_index_entries;
3584	AVIndexEntry *index_entries = s->streams[0]->index_entries;
3585	if (ts >= matroska->duration * matroska->time_scale) return (CueDesc) {-1, -1, -1, -1};
3586	for (i = 1; i < nb_index_entries; i++) {
3587	if (index_entries[i - 1].timestamp * matroska->time_scale <= ts &&
3588	index_entries[i].timestamp * matroska->time_scale > ts) {
3589	break;
3590	}
3591	}
3592	--i;
3593	cue_desc.start_time_ns = index_entries[i].timestamp * matroska->time_scale;
3594	cue_desc.start_offset = index_entries[i].pos - matroska->segment_start;
3595	if (i != nb_index_entries - 1) {
3596	cue_desc.end_time_ns = index_entries[i + 1].timestamp * matroska->time_scale;
3597	cue_desc.end_offset = index_entries[i + 1].pos - matroska->segment_start;
3598	} else {
3599	cue_desc.end_time_ns = matroska->duration * matroska->time_scale;
3600	// FIXME: this needs special handling for files where Cues appear
3601	// before Clusters. the current logic assumes Cues appear after
3602	// Clusters.
3603	cue_desc.end_offset = cues_start - matroska->segment_start;
3604	}
3605	return cue_desc;
3606	}
3607
3608	static int webm_clusters_start_with_keyframe(AVFormatContext *s)
3609	{
3610	MatroskaDemuxContext *matroska = s->priv_data;
3611	int64_t cluster_pos, before_pos;
3612	int index, rv = 1;
3613	if (s->streams[0]->nb_index_entries <= 0) return 0;
3614	// seek to the first cluster using cues.
3615	index = av_index_search_timestamp(s->streams[0], 0, 0);
3616	if (index < 0) return 0;
3617	cluster_pos = s->streams[0]->index_entries[index].pos;
3618	before_pos = avio_tell(s->pb);
3619	while (1) {
3620	int64_t cluster_id = 0, cluster_length = 0;
3621	AVPacket *pkt;
3622	avio_seek(s->pb, cluster_pos, SEEK_SET);
3623	// read cluster id and length
3624	ebml_read_num(matroska, matroska->ctx->pb, 4, &cluster_id);
3625	ebml_read_length(matroska, matroska->ctx->pb, &cluster_length);
3626	if (cluster_id != 0xF43B675) { // done with all clusters
3627	break;
3628	}
3629	avio_seek(s->pb, cluster_pos, SEEK_SET);
3630	matroska->current_id = 0;
3631	matroska_clear_queue(matroska);
3632	if (matroska_parse_cluster(matroska) < 0 ||
3633	matroska->num_packets <= 0) {
3634	break;
3635	}
3636	pkt = matroska->packets[0];
3637	cluster_pos += cluster_length + 12; // 12 is the offset of the cluster id and length.
3638	if (!(pkt->flags & AV_PKT_FLAG_KEY)) {
3639	rv = 0;
3640	break;
3641	}
3642	}
3643	avio_seek(s->pb, before_pos, SEEK_SET);
3644	return rv;
3645	}
3646
3647	static int buffer_size_after_time_downloaded(int64_t time_ns, double search_sec, int64_t bps,
3648	double min_buffer, double* buffer,
3649	double* sec_to_download, AVFormatContext *s,
3650	int64_t cues_start)
3651	{
3652	double nano_seconds_per_second = 1000000000.0;
3653	double time_sec = time_ns / nano_seconds_per_second;
3654	int rv = 0;
3655	int64_t time_to_search_ns = (int64_t)(search_sec * nano_seconds_per_second);
3656	int64_t end_time_ns = time_ns + time_to_search_ns;
3657	double sec_downloaded = 0.0;
3658	CueDesc desc_curr = get_cue_desc(s, time_ns, cues_start);
3659	if (desc_curr.start_time_ns == -1)
3660	return -1;
3661	*sec_to_download = 0.0;
3662
3663	// Check for non cue start time.
3664	if (time_ns > desc_curr.start_time_ns) {
3665	int64_t cue_nano = desc_curr.end_time_ns - time_ns;
3666	double percent = (double)(cue_nano) / (desc_curr.end_time_ns - desc_curr.start_time_ns);
3667	double cueBytes = (desc_curr.end_offset - desc_curr.start_offset) * percent;
3668	double timeToDownload = (cueBytes * 8.0) / bps;
3669
3670	sec_downloaded += (cue_nano / nano_seconds_per_second) - timeToDownload;
3671	*sec_to_download += timeToDownload;
3672
3673	// Check if the search ends within the first cue.
3674	if (desc_curr.end_time_ns >= end_time_ns) {
3675	double desc_end_time_sec = desc_curr.end_time_ns / nano_seconds_per_second;
3676	double percent_to_sub = search_sec / (desc_end_time_sec - time_sec);
3677	sec_downloaded = percent_to_sub * sec_downloaded;
3678	*sec_to_download = percent_to_sub * *sec_to_download;
3679	}
3680
3681	if ((sec_downloaded + *buffer) <= min_buffer) {
3682	return 1;
3683	}
3684
3685	// Get the next Cue.
3686	desc_curr = get_cue_desc(s, desc_curr.end_time_ns, cues_start);
3687	}
3688
3689	while (desc_curr.start_time_ns != -1) {
3690	int64_t desc_bytes = desc_curr.end_offset - desc_curr.start_offset;
3691	int64_t desc_ns = desc_curr.end_time_ns - desc_curr.start_time_ns;
3692	double desc_sec = desc_ns / nano_seconds_per_second;
3693	double bits = (desc_bytes * 8.0);
3694	double time_to_download = bits / bps;
3695
3696	sec_downloaded += desc_sec - time_to_download;
3697	*sec_to_download += time_to_download;
3698
3699	if (desc_curr.end_time_ns >= end_time_ns) {
3700	double desc_end_time_sec = desc_curr.end_time_ns / nano_seconds_per_second;
3701	double percent_to_sub = search_sec / (desc_end_time_sec - time_sec);
3702	sec_downloaded = percent_to_sub * sec_downloaded;
3703	*sec_to_download = percent_to_sub * *sec_to_download;
3704
3705	if ((sec_downloaded + *buffer) <= min_buffer)
3706	rv = 1;
3707	break;
3708	}
3709
3710	if ((sec_downloaded + *buffer) <= min_buffer) {
3711	rv = 1;
3712	break;
3713	}
3714
3715	desc_curr = get_cue_desc(s, desc_curr.end_time_ns, cues_start);
3716	}
3717	*buffer = *buffer + sec_downloaded;
3718	return rv;
3719	}
3720
3721	/* This function computes the bandwidth of the WebM file with the help of
3722	* buffer_size_after_time_downloaded() function. Both of these functions are
3723	* adapted from WebM Tools project and are adapted to work with FFmpeg's
3724	* Matroska parsing mechanism.
3725	*
3726	* Returns the bandwidth of the file on success; -1 on error.
3727	* */
3728	static int64_t webm_dash_manifest_compute_bandwidth(AVFormatContext *s, int64_t cues_start)
3729	{
3730	MatroskaDemuxContext *matroska = s->priv_data;
3731	AVStream *st = s->streams[0];
3732	double bandwidth = 0.0;
3733	int i;
3734
3735	for (i = 0; i < st->nb_index_entries; i++) {
3736	int64_t prebuffer_ns = 1000000000;
3737	int64_t time_ns = st->index_entries[i].timestamp * matroska->time_scale;
3738	double nano_seconds_per_second = 1000000000.0;
3739	int64_t prebuffered_ns = time_ns + prebuffer_ns;
3740	double prebuffer_bytes = 0.0;
3741	int64_t temp_prebuffer_ns = prebuffer_ns;
3742	int64_t pre_bytes, pre_ns;
3743	double pre_sec, prebuffer, bits_per_second;
3744	CueDesc desc_beg = get_cue_desc(s, time_ns, cues_start);
3745
3746	// Start with the first Cue.
3747	CueDesc desc_end = desc_beg;
3748
3749	// Figure out how much data we have downloaded for the prebuffer. This will
3750	// be used later to adjust the bits per sample to try.
3751	while (desc_end.start_time_ns != -1 && desc_end.end_time_ns < prebuffered_ns) {
3752	// Prebuffered the entire Cue.
3753	prebuffer_bytes += desc_end.end_offset - desc_end.start_offset;
3754	temp_prebuffer_ns -= desc_end.end_time_ns - desc_end.start_time_ns;
3755	desc_end = get_cue_desc(s, desc_end.end_time_ns, cues_start);
3756	}
3757	if (desc_end.start_time_ns == -1) {
3758	// The prebuffer is larger than the duration.
3759	if (matroska->duration * matroska->time_scale >= prebuffered_ns)
3760	return -1;
3761	bits_per_second = 0.0;
3762	} else {
3763	// The prebuffer ends in the last Cue. Estimate how much data was
3764	// prebuffered.
3765	pre_bytes = desc_end.end_offset - desc_end.start_offset;
3766	pre_ns = desc_end.end_time_ns - desc_end.start_time_ns;
3767	pre_sec = pre_ns / nano_seconds_per_second;
3768	prebuffer_bytes +=
3769	pre_bytes * ((temp_prebuffer_ns / nano_seconds_per_second) / pre_sec);
3770
3771	prebuffer = prebuffer_ns / nano_seconds_per_second;
3772
3773	// Set this to 0.0 in case our prebuffer buffers the entire video.
3774	bits_per_second = 0.0;
3775	do {
3776	int64_t desc_bytes = desc_end.end_offset - desc_beg.start_offset;
3777	int64_t desc_ns = desc_end.end_time_ns - desc_beg.start_time_ns;
3778	double desc_sec = desc_ns / nano_seconds_per_second;
3779	double calc_bits_per_second = (desc_bytes * 8) / desc_sec;
3780
3781	// Drop the bps by the percentage of bytes buffered.
3782	double percent = (desc_bytes - prebuffer_bytes) / desc_bytes;
3783	double mod_bits_per_second = calc_bits_per_second * percent;
3784
3785	if (prebuffer < desc_sec) {
3786	double search_sec =
3787	(double)(matroska->duration * matroska->time_scale) / nano_seconds_per_second;
3788
3789	// Add 1 so the bits per second should be a little bit greater than file
3790	// datarate.
3791	int64_t bps = (int64_t)(mod_bits_per_second) + 1;
3792	const double min_buffer = 0.0;
3793	double buffer = prebuffer;
3794	double sec_to_download = 0.0;
3795
3796	int rv = buffer_size_after_time_downloaded(prebuffered_ns, search_sec, bps,
3797	min_buffer, &buffer, &sec_to_download,
3798	s, cues_start);
3799	if (rv < 0) {
3800	return -1;
3801	} else if (rv == 0) {
3802	bits_per_second = (double)(bps);
3803	break;
3804	}
3805	}
3806
3807	desc_end = get_cue_desc(s, desc_end.end_time_ns, cues_start);
3808	} while (desc_end.start_time_ns != -1);
3809	}
3810	if (bandwidth < bits_per_second) bandwidth = bits_per_second;
3811	}
3812	return (int64_t)bandwidth;
3813	}
3814
3815	static int webm_dash_manifest_cues(AVFormatContext *s)
3816	{
3817	MatroskaDemuxContext *matroska = s->priv_data;
3818	EbmlList *seekhead_list = &matroska->seekhead;
3819	MatroskaSeekhead *seekhead = seekhead_list->elem;
3820	char *buf;
3821	int64_t cues_start = -1, cues_end = -1, before_pos, bandwidth;
3822	int i;
3823
3824	// determine cues start and end positions
3825	for (i = 0; i < seekhead_list->nb_elem; i++)
3826	if (seekhead[i].id == MATROSKA_ID_CUES)
3827	break;
3828
3829	if (i >= seekhead_list->nb_elem) return -1;
3830
3831	before_pos = avio_tell(matroska->ctx->pb);
3832	cues_start = seekhead[i].pos + matroska->segment_start;
3833	if (avio_seek(matroska->ctx->pb, cues_start, SEEK_SET) == cues_start) {
3834	// cues_end is computed as cues_start + cues_length + length of the
3835	// Cues element ID + EBML length of the Cues element. cues_end is
3836	// inclusive and the above sum is reduced by 1.
3837	uint64_t cues_length = 0, cues_id = 0, bytes_read = 0;
3838	bytes_read += ebml_read_num(matroska, matroska->ctx->pb, 4, &cues_id);
3839	bytes_read += ebml_read_length(matroska, matroska->ctx->pb, &cues_length);
3840	cues_end = cues_start + cues_length + bytes_read - 1;
3841	}
3842	avio_seek(matroska->ctx->pb, before_pos, SEEK_SET);
3843	if (cues_start == -1 || cues_end == -1) return -1;
3844
3845	// parse the cues
3846	matroska_parse_cues(matroska);
3847
3848	// cues start
3849	av_dict_set_int(&s->streams[0]->metadata, CUES_START, cues_start, 0);
3850
3851	// cues end
3852	av_dict_set_int(&s->streams[0]->metadata, CUES_END, cues_end, 0);
3853
3854	// bandwidth
3855	bandwidth = webm_dash_manifest_compute_bandwidth(s, cues_start);
3856	if (bandwidth < 0) return -1;
3857	av_dict_set_int(&s->streams[0]->metadata, BANDWIDTH, bandwidth, 0);
3858
3859	// check if all clusters start with key frames
3860	av_dict_set_int(&s->streams[0]->metadata, CLUSTER_KEYFRAME, webm_clusters_start_with_keyframe(s), 0);
3861
3862	// store cue point timestamps as a comma separated list for checking subsegment alignment in
3863	// the muxer. assumes that each timestamp cannot be more than 20 characters long.
3864	buf = av_malloc_array(s->streams[0]->nb_index_entries, 20 * sizeof(char));
3865	if (!buf) return -1;
3866	strcpy(buf, "");
3867	for (i = 0; i < s->streams[0]->nb_index_entries; i++) {
3868	snprintf(buf, (i + 1) * 20 * sizeof(char),
3869	"%s%" PRId64, buf, s->streams[0]->index_entries[i].timestamp);
3870	if (i != s->streams[0]->nb_index_entries - 1)
3871	strncat(buf, ",", sizeof(char));
3872	}
3873	av_dict_set(&s->streams[0]->metadata, CUE_TIMESTAMPS, buf, 0);
3874	av_free(buf);
3875
3876	return 0;
3877	}
3878
3879	static int webm_dash_manifest_read_header(AVFormatContext *s)
3880	{
3881	char *buf;
3882	int ret = matroska_read_header(s);
3883	MatroskaTrack *tracks;
3884	MatroskaDemuxContext *matroska = s->priv_data;
3885	if (ret) {
3886	av_log(s, AV_LOG_ERROR, "Failed to read file headers\n");
3887	return -1;
3888	}
3889	if (!s->nb_streams) {
3890	matroska_read_close(s);
3891	av_log(s, AV_LOG_ERROR, "No streams found\n");
3892	return AVERROR_INVALIDDATA;
3893	}
3894
3895	if (!matroska->is_live) {
3896	buf = av_asprintf("%g", matroska->duration);
3897	if (!buf) return AVERROR(ENOMEM);
3898	av_dict_set(&s->streams[0]->metadata, DURATION, buf, 0);
3899	av_free(buf);
3900
3901	// initialization range
3902	// 5 is the offset of Cluster ID.
3903	av_dict_set_int(&s->streams[0]->metadata, INITIALIZATION_RANGE, avio_tell(s->pb) - 5, 0);
3904	}
3905
3906	// basename of the file
3907	buf = strrchr(s->filename, '/');
3908	av_dict_set(&s->streams[0]->metadata, FILENAME, buf ? ++buf : s->filename, 0);
3909
3910	// track number
3911	tracks = matroska->tracks.elem;
3912	av_dict_set_int(&s->streams[0]->metadata, TRACK_NUMBER, tracks[0].num, 0);
3913
3914	// parse the cues and populate Cue related fields
3915	return matroska->is_live ? 0 : webm_dash_manifest_cues(s);
3916	}
3917
3918	static int webm_dash_manifest_read_packet(AVFormatContext *s, AVPacket *pkt)
3919	{
3920	return AVERROR_EOF;
3921	}
3922
3923	#define OFFSET(x) offsetof(MatroskaDemuxContext, x)
3924	static const AVOption options[] = {
3925	{ "live", "flag indicating that the input is a live file that only has the headers.", OFFSET(is_live), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM },
3926	{ NULL },
3927	};
3928
3929	static const AVClass webm_dash_class = {
3930	.class_name = "WebM DASH Manifest demuxer",
3931	.item_name = av_default_item_name,
3932	.option = options,
3933	.version = LIBAVUTIL_VERSION_INT,
3934	};
3935
3936	AVInputFormat ff_matroska_demuxer = {
3937	.name = "matroska,webm",
3938	.long_name = NULL_IF_CONFIG_SMALL("Matroska / WebM"),
3939	.extensions = "mkv,mk3d,mka,mks",
3940	.priv_data_size = sizeof(MatroskaDemuxContext),
3941	.read_probe = matroska_probe,
3942	.read_header = matroska_read_header,
3943	.read_packet = matroska_read_packet,
3944	.read_close = matroska_read_close,
3945	.read_seek = matroska_read_seek,
3946	.mime_type = "audio/webm,audio/x-matroska,video/webm,video/x-matroska"
3947	};
3948
3949	AVInputFormat ff_webm_dash_manifest_demuxer = {
3950	.name = "webm_dash_manifest",
3951	.long_name = NULL_IF_CONFIG_SMALL("WebM DASH Manifest"),
3952	.priv_data_size = sizeof(MatroskaDemuxContext),
3953	.read_header = webm_dash_manifest_read_header,
3954	.read_packet = webm_dash_manifest_read_packet,
3955	.read_close = matroska_read_close,
3956	.priv_class = &webm_dash_class,
3957	};
3958