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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 #include "libavcodec/packet_internal.h"
52 
53 #include "avformat.h"
54 #include "avio_internal.h"
55 #include "internal.h"
56 #include "isom.h"
57 #include "matroska.h"
58 #include "oggdec.h"
59 /* For ff_codec_get_id(). */
60 #include "riff.h"
61 #include "rmsipr.h"
62 
63 #if CONFIG_BZLIB
64 #include <bzlib.h>
65 #endif
66 #if CONFIG_ZLIB
67 #include <zlib.h>
68 #endif
69 
70 #include "qtpalette.h"
71 
72 #define EBML_UNKNOWN_LENGTH  UINT64_MAX /* EBML unknown length, in uint64_t */
73 #define NEEDS_CHECKING                2 /* Indicates that some error checks
74                                          * still need to be performed */
75 #define LEVEL_ENDED                   3 /* return value of ebml_parse when the
76                                          * syntax level used for parsing ended. */
77 #define SKIP_THRESHOLD      1024 * 1024 /* In non-seekable mode, if more than SKIP_THRESHOLD
78                                          * of unkown, potentially damaged data is encountered,
79                                          * it is considered an error. */
80 #define UNKNOWN_EQUIV         50 * 1024 /* An unknown element is considered equivalent
81                                          * to this many bytes of unknown data for the
82                                          * SKIP_THRESHOLD check. */
83 
84 typedef enum {
85     EBML_NONE,
86     EBML_UINT,
87     EBML_SINT,
88     EBML_FLOAT,
89     EBML_STR,
90     EBML_UTF8,
91     EBML_BIN,
92     EBML_NEST,
93     EBML_LEVEL1,
94     EBML_STOP,
95     EBML_TYPE_COUNT
96 } EbmlType;
97 
98 typedef struct CountedElement {
99     union {
100         uint64_t  u;
101         int64_t   i;
102         double    f;
103         char     *s;
104     } el;
105     unsigned count;
106 } CountedElement;
107 
108 typedef const struct EbmlSyntax {
109     uint32_t id;
110     uint8_t type;
111     uint8_t is_counted;
112     size_t list_elem_size;
113     size_t data_offset;
114     union {
115         int64_t     i;
116         uint64_t    u;
117         double      f;
118         const char *s;
119         const struct EbmlSyntax *n;
120     } def;
121 } EbmlSyntax;
122 
123 typedef struct EbmlList {
124     int nb_elem;
125     unsigned int alloc_elem_size;
126     void *elem;
127 } EbmlList;
128 
129 typedef struct EbmlBin {
130     int      size;
131     AVBufferRef *buf;
132     uint8_t *data;
133     int64_t  pos;
134 } EbmlBin;
135 
136 typedef struct Ebml {
137     uint64_t version;
138     uint64_t max_size;
139     uint64_t id_length;
140     char    *doctype;
141     uint64_t doctype_version;
142 } Ebml;
143 
144 typedef struct MatroskaTrackCompression {
145     uint64_t algo;
146     EbmlBin  settings;
147 } MatroskaTrackCompression;
148 
149 typedef struct MatroskaTrackEncryption {
150     uint64_t algo;
151     EbmlBin  key_id;
152 } MatroskaTrackEncryption;
153 
154 typedef struct MatroskaTrackEncoding {
155     uint64_t scope;
156     uint64_t type;
157     MatroskaTrackCompression compression;
158     MatroskaTrackEncryption encryption;
159 } MatroskaTrackEncoding;
160 
161 typedef struct MatroskaMasteringMeta {
162     double r_x;
163     double r_y;
164     double g_x;
165     double g_y;
166     double b_x;
167     double b_y;
168     double white_x;
169     double white_y;
170     double max_luminance;
171     CountedElement min_luminance;
172 } MatroskaMasteringMeta;
173 
174 typedef struct MatroskaTrackVideoColor {
175     uint64_t matrix_coefficients;
176     uint64_t bits_per_channel;
177     uint64_t chroma_sub_horz;
178     uint64_t chroma_sub_vert;
179     uint64_t cb_sub_horz;
180     uint64_t cb_sub_vert;
181     uint64_t chroma_siting_horz;
182     uint64_t chroma_siting_vert;
183     uint64_t range;
184     uint64_t transfer_characteristics;
185     uint64_t primaries;
186     uint64_t max_cll;
187     uint64_t max_fall;
188     MatroskaMasteringMeta mastering_meta;
189 } MatroskaTrackVideoColor;
190 
191 typedef struct MatroskaTrackVideoProjection {
192     uint64_t type;
193     EbmlBin private;
194     double yaw;
195     double pitch;
196     double roll;
197 } MatroskaTrackVideoProjection;
198 
199 typedef struct MatroskaTrackVideo {
200     double   frame_rate;
201     uint64_t display_width;
202     uint64_t display_height;
203     uint64_t pixel_width;
204     uint64_t pixel_height;
205     EbmlBin  color_space;
206     uint64_t display_unit;
207     uint64_t interlaced;
208     uint64_t field_order;
209     uint64_t stereo_mode;
210     uint64_t alpha_mode;
211     EbmlList color;
212     MatroskaTrackVideoProjection projection;
213 } MatroskaTrackVideo;
214 
215 typedef struct MatroskaTrackAudio {
216     double   samplerate;
217     double   out_samplerate;
218     uint64_t bitdepth;
219     uint64_t channels;
220 
221     /* real audio header (extracted from extradata) */
222     int      coded_framesize;
223     int      sub_packet_h;
224     int      frame_size;
225     int      sub_packet_size;
226     int      sub_packet_cnt;
227     int      pkt_cnt;
228     uint64_t buf_timecode;
229     uint8_t *buf;
230 } MatroskaTrackAudio;
231 
232 typedef struct MatroskaTrackPlane {
233     uint64_t uid;
234     uint64_t type;
235 } MatroskaTrackPlane;
236 
237 typedef struct MatroskaTrackOperation {
238     EbmlList combine_planes;
239 } MatroskaTrackOperation;
240 
241 typedef struct MatroskaTrack {
242     uint64_t num;
243     uint64_t uid;
244     uint64_t type;
245     char    *name;
246     char    *codec_id;
247     EbmlBin  codec_priv;
248     char    *language;
249     double time_scale;
250     uint64_t default_duration;
251     uint64_t flag_default;
252     uint64_t flag_forced;
253     uint64_t flag_comment;
254     uint64_t flag_hearingimpaired;
255     uint64_t flag_visualimpaired;
256     uint64_t flag_textdescriptions;
257     CountedElement flag_original;
258     uint64_t seek_preroll;
259     MatroskaTrackVideo video;
260     MatroskaTrackAudio audio;
261     MatroskaTrackOperation operation;
262     EbmlList encodings;
263     uint64_t codec_delay;
264     uint64_t codec_delay_in_track_tb;
265 
266     AVStream *stream;
267     int64_t end_timecode;
268     int ms_compat;
269     int needs_decoding;
270     uint64_t max_block_additional_id;
271 
272     uint32_t palette[AVPALETTE_COUNT];
273     int has_palette;
274 } MatroskaTrack;
275 
276 typedef struct MatroskaAttachment {
277     uint64_t uid;
278     char *filename;
279     char *description;
280     char *mime;
281     EbmlBin bin;
282 
283     AVStream *stream;
284 } MatroskaAttachment;
285 
286 typedef struct MatroskaChapter {
287     uint64_t start;
288     uint64_t end;
289     uint64_t uid;
290     char    *title;
291 
292     AVChapter *chapter;
293 } MatroskaChapter;
294 
295 typedef struct MatroskaIndexPos {
296     uint64_t track;
297     uint64_t pos;
298 } MatroskaIndexPos;
299 
300 typedef struct MatroskaIndex {
301     uint64_t time;
302     EbmlList pos;
303 } MatroskaIndex;
304 
305 typedef struct MatroskaTag {
306     char *name;
307     char *string;
308     char *lang;
309     uint64_t def;
310     EbmlList sub;
311 } MatroskaTag;
312 
313 typedef struct MatroskaTagTarget {
314     char    *type;
315     uint64_t typevalue;
316     uint64_t trackuid;
317     uint64_t chapteruid;
318     uint64_t attachuid;
319 } MatroskaTagTarget;
320 
321 typedef struct MatroskaTags {
322     MatroskaTagTarget target;
323     EbmlList tag;
324 } MatroskaTags;
325 
326 typedef struct MatroskaSeekhead {
327     uint64_t id;
328     uint64_t pos;
329 } MatroskaSeekhead;
330 
331 typedef struct MatroskaLevel {
332     uint64_t start;
333     uint64_t length;
334 } MatroskaLevel;
335 
336 typedef struct MatroskaBlock {
337     uint64_t duration;
338     CountedElement reference;
339     uint64_t non_simple;
340     EbmlBin  bin;
341     uint64_t additional_id;
342     EbmlBin  additional;
343     int64_t  discard_padding;
344 } MatroskaBlock;
345 
346 typedef struct MatroskaCluster {
347     MatroskaBlock block;
348     uint64_t timecode;
349     int64_t pos;
350 } MatroskaCluster;
351 
352 typedef struct MatroskaLevel1Element {
353     int64_t  pos;
354     uint32_t id;
355     int parsed;
356 } MatroskaLevel1Element;
357 
358 typedef struct MatroskaDemuxContext {
359     const AVClass *class;
360     AVFormatContext *ctx;
361 
362     /* EBML stuff */
363     MatroskaLevel levels[EBML_MAX_DEPTH];
364     int      num_levels;
365     uint32_t current_id;
366     int64_t  resync_pos;
367     int      unknown_count;
368 
369     uint64_t time_scale;
370     double   duration;
371     char    *title;
372     char    *muxingapp;
373     EbmlBin  date_utc;
374     EbmlList tracks;
375     EbmlList attachments;
376     EbmlList chapters;
377     EbmlList index;
378     EbmlList tags;
379     EbmlList seekhead;
380 
381     /* byte position of the segment inside the stream */
382     int64_t segment_start;
383 
384     AVPacket *pkt;
385 
386     /* the packet queue */
387     PacketList *queue;
388     PacketList *queue_end;
389 
390     int done;
391 
392     /* What to skip before effectively reading a packet. */
393     int skip_to_keyframe;
394     uint64_t skip_to_timecode;
395 
396     /* File has a CUES element, but we defer parsing until it is needed. */
397     int cues_parsing_deferred;
398 
399     /* Level1 elements and whether they were read yet */
400     MatroskaLevel1Element level1_elems[64];
401     int num_level1_elems;
402 
403     MatroskaCluster current_cluster;
404 
405     /* WebM DASH Manifest live flag */
406     int is_live;
407 
408     /* Bandwidth value for WebM DASH Manifest */
409     int bandwidth;
410 } MatroskaDemuxContext;
411 
412 #define CHILD_OF(parent) { .def = { .n = parent } }
413 
414 // The following forward declarations need their size because
415 // a tentative definition with internal linkage must not be an
416 // incomplete type (6.7.2 in C90, 6.9.2 in C99).
417 // Removing the sizes breaks MSVC.
418 static EbmlSyntax ebml_syntax[3], matroska_segment[9], matroska_track_video_color[15], matroska_track_video[19],
419                   matroska_track[32], matroska_track_encoding[6], matroska_track_encodings[2],
420                   matroska_track_combine_planes[2], matroska_track_operation[2], matroska_tracks[2],
421                   matroska_attachments[2], matroska_chapter_entry[9], matroska_chapter[6], matroska_chapters[2],
422                   matroska_index_entry[3], matroska_index[2], matroska_tag[3], matroska_tags[2], matroska_seekhead[2],
423                   matroska_blockadditions[2], matroska_blockgroup[8], matroska_cluster_parsing[8];
424 
425 static EbmlSyntax ebml_header[] = {
426     { EBML_ID_EBMLREADVERSION,    EBML_UINT, 0, 0, offsetof(Ebml, version),         { .u = EBML_VERSION } },
427     { EBML_ID_EBMLMAXSIZELENGTH,  EBML_UINT, 0, 0, offsetof(Ebml, max_size),        { .u = 8 } },
428     { EBML_ID_EBMLMAXIDLENGTH,    EBML_UINT, 0, 0, offsetof(Ebml, id_length),       { .u = 4 } },
429     { EBML_ID_DOCTYPE,            EBML_STR,  0, 0, offsetof(Ebml, doctype),         { .s = "(none)" } },
430     { EBML_ID_DOCTYPEREADVERSION, EBML_UINT, 0, 0, offsetof(Ebml, doctype_version), { .u = 1 } },
431     { EBML_ID_EBMLVERSION,        EBML_NONE },
432     { EBML_ID_DOCTYPEVERSION,     EBML_NONE },
433     CHILD_OF(ebml_syntax)
434 };
435 
436 static EbmlSyntax ebml_syntax[] = {
437     { EBML_ID_HEADER,      EBML_NEST, 0, 0, 0, { .n = ebml_header } },
438     { MATROSKA_ID_SEGMENT, EBML_STOP },
439     { 0 }
440 };
441 
442 static EbmlSyntax matroska_info[] = {
443     { MATROSKA_ID_TIMECODESCALE, EBML_UINT,  0, 0, offsetof(MatroskaDemuxContext, time_scale), { .u = 1000000 } },
444     { MATROSKA_ID_DURATION,      EBML_FLOAT, 0, 0, offsetof(MatroskaDemuxContext, duration) },
445     { MATROSKA_ID_TITLE,         EBML_UTF8,  0, 0, offsetof(MatroskaDemuxContext, title) },
446     { MATROSKA_ID_WRITINGAPP,    EBML_NONE },
447     { MATROSKA_ID_MUXINGAPP,     EBML_UTF8, 0, 0, offsetof(MatroskaDemuxContext, muxingapp) },
448     { MATROSKA_ID_DATEUTC,       EBML_BIN,  0, 0, offsetof(MatroskaDemuxContext, date_utc) },
449     { MATROSKA_ID_SEGMENTUID,    EBML_NONE },
450     CHILD_OF(matroska_segment)
451 };
452 
453 static EbmlSyntax matroska_mastering_meta[] = {
454     { MATROSKA_ID_VIDEOCOLOR_RX, EBML_FLOAT, 0, 0, offsetof(MatroskaMasteringMeta, r_x) },
455     { MATROSKA_ID_VIDEOCOLOR_RY, EBML_FLOAT, 0, 0, offsetof(MatroskaMasteringMeta, r_y) },
456     { MATROSKA_ID_VIDEOCOLOR_GX, EBML_FLOAT, 0, 0, offsetof(MatroskaMasteringMeta, g_x) },
457     { MATROSKA_ID_VIDEOCOLOR_GY, EBML_FLOAT, 0, 0, offsetof(MatroskaMasteringMeta, g_y) },
458     { MATROSKA_ID_VIDEOCOLOR_BX, EBML_FLOAT, 0, 0, offsetof(MatroskaMasteringMeta, b_x) },
459     { MATROSKA_ID_VIDEOCOLOR_BY, EBML_FLOAT, 0, 0, offsetof(MatroskaMasteringMeta, b_y) },
460     { MATROSKA_ID_VIDEOCOLOR_WHITEX, EBML_FLOAT, 0, 0, offsetof(MatroskaMasteringMeta, white_x) },
461     { MATROSKA_ID_VIDEOCOLOR_WHITEY, EBML_FLOAT, 0, 0, offsetof(MatroskaMasteringMeta, white_y) },
462     { MATROSKA_ID_VIDEOCOLOR_LUMINANCEMIN, EBML_FLOAT, 1, 0, offsetof(MatroskaMasteringMeta, min_luminance) },
463     { MATROSKA_ID_VIDEOCOLOR_LUMINANCEMAX, EBML_FLOAT, 0, 0, offsetof(MatroskaMasteringMeta, max_luminance) },
464     CHILD_OF(matroska_track_video_color)
465 };
466 
467 static EbmlSyntax matroska_track_video_color[] = {
468     { MATROSKA_ID_VIDEOCOLORMATRIXCOEFF,      EBML_UINT, 0, 0, offsetof(MatroskaTrackVideoColor, matrix_coefficients), { .u = AVCOL_SPC_UNSPECIFIED } },
469     { MATROSKA_ID_VIDEOCOLORBITSPERCHANNEL,   EBML_UINT, 0, 0, offsetof(MatroskaTrackVideoColor, bits_per_channel), { .u = 0 } },
470     { MATROSKA_ID_VIDEOCOLORCHROMASUBHORZ,    EBML_UINT, 0, 0, offsetof(MatroskaTrackVideoColor, chroma_sub_horz) },
471     { MATROSKA_ID_VIDEOCOLORCHROMASUBVERT,    EBML_UINT, 0, 0, offsetof(MatroskaTrackVideoColor, chroma_sub_vert) },
472     { MATROSKA_ID_VIDEOCOLORCBSUBHORZ,        EBML_UINT, 0, 0, offsetof(MatroskaTrackVideoColor, cb_sub_horz) },
473     { MATROSKA_ID_VIDEOCOLORCBSUBVERT,        EBML_UINT, 0, 0, offsetof(MatroskaTrackVideoColor, cb_sub_vert) },
474     { MATROSKA_ID_VIDEOCOLORCHROMASITINGHORZ, EBML_UINT, 0, 0, offsetof(MatroskaTrackVideoColor, chroma_siting_horz), { .u = MATROSKA_COLOUR_CHROMASITINGHORZ_UNDETERMINED } },
475     { MATROSKA_ID_VIDEOCOLORCHROMASITINGVERT, EBML_UINT, 0, 0, offsetof(MatroskaTrackVideoColor, chroma_siting_vert), { .u = MATROSKA_COLOUR_CHROMASITINGVERT_UNDETERMINED } },
476     { MATROSKA_ID_VIDEOCOLORRANGE,            EBML_UINT, 0, 0, offsetof(MatroskaTrackVideoColor, range), { .u = AVCOL_RANGE_UNSPECIFIED } },
477     { MATROSKA_ID_VIDEOCOLORTRANSFERCHARACTERISTICS, EBML_UINT, 0, 0, offsetof(MatroskaTrackVideoColor, transfer_characteristics), { .u = AVCOL_TRC_UNSPECIFIED } },
478     { MATROSKA_ID_VIDEOCOLORPRIMARIES,        EBML_UINT, 0, 0, offsetof(MatroskaTrackVideoColor, primaries), { .u = AVCOL_PRI_UNSPECIFIED } },
479     { MATROSKA_ID_VIDEOCOLORMAXCLL,           EBML_UINT, 0, 0, offsetof(MatroskaTrackVideoColor, max_cll) },
480     { MATROSKA_ID_VIDEOCOLORMAXFALL,          EBML_UINT, 0, 0, offsetof(MatroskaTrackVideoColor, max_fall) },
481     { MATROSKA_ID_VIDEOCOLORMASTERINGMETA,    EBML_NEST, 0, 0, offsetof(MatroskaTrackVideoColor, mastering_meta), { .n = matroska_mastering_meta } },
482     CHILD_OF(matroska_track_video)
483 };
484 
485 static EbmlSyntax matroska_track_video_projection[] = {
486     { MATROSKA_ID_VIDEOPROJECTIONTYPE,        EBML_UINT,  0, 0, offsetof(MatroskaTrackVideoProjection, type), { .u = MATROSKA_VIDEO_PROJECTION_TYPE_RECTANGULAR } },
487     { MATROSKA_ID_VIDEOPROJECTIONPRIVATE,     EBML_BIN,   0, 0, offsetof(MatroskaTrackVideoProjection, private) },
488     { MATROSKA_ID_VIDEOPROJECTIONPOSEYAW,     EBML_FLOAT, 0, 0, offsetof(MatroskaTrackVideoProjection, yaw),   { .f = 0.0 } },
489     { MATROSKA_ID_VIDEOPROJECTIONPOSEPITCH,   EBML_FLOAT, 0, 0, offsetof(MatroskaTrackVideoProjection, pitch), { .f = 0.0 } },
490     { MATROSKA_ID_VIDEOPROJECTIONPOSEROLL,    EBML_FLOAT, 0, 0, offsetof(MatroskaTrackVideoProjection, roll),  { .f = 0.0 } },
491     CHILD_OF(matroska_track_video)
492 };
493 
494 static EbmlSyntax matroska_track_video[] = {
495     { MATROSKA_ID_VIDEOFRAMERATE,      EBML_FLOAT, 0, 0, offsetof(MatroskaTrackVideo, frame_rate) },
496     { MATROSKA_ID_VIDEODISPLAYWIDTH,   EBML_UINT,  0, 0, offsetof(MatroskaTrackVideo, display_width), { .u=-1 } },
497     { MATROSKA_ID_VIDEODISPLAYHEIGHT,  EBML_UINT,  0, 0, offsetof(MatroskaTrackVideo, display_height), { .u=-1 } },
498     { MATROSKA_ID_VIDEOPIXELWIDTH,     EBML_UINT,  0, 0, offsetof(MatroskaTrackVideo, pixel_width) },
499     { MATROSKA_ID_VIDEOPIXELHEIGHT,    EBML_UINT,  0, 0, offsetof(MatroskaTrackVideo, pixel_height) },
500     { MATROSKA_ID_VIDEOCOLORSPACE,     EBML_BIN,   0, 0, offsetof(MatroskaTrackVideo, color_space) },
501     { MATROSKA_ID_VIDEOALPHAMODE,      EBML_UINT,  0, 0, offsetof(MatroskaTrackVideo, alpha_mode), { .u = 0 } },
502     { MATROSKA_ID_VIDEOCOLOR,          EBML_NEST,  0, sizeof(MatroskaTrackVideoColor), offsetof(MatroskaTrackVideo, color), { .n = matroska_track_video_color } },
503     { MATROSKA_ID_VIDEOPROJECTION,     EBML_NEST,  0, 0, offsetof(MatroskaTrackVideo, projection), { .n = matroska_track_video_projection } },
504     { MATROSKA_ID_VIDEOPIXELCROPB,     EBML_NONE },
505     { MATROSKA_ID_VIDEOPIXELCROPT,     EBML_NONE },
506     { MATROSKA_ID_VIDEOPIXELCROPL,     EBML_NONE },
507     { MATROSKA_ID_VIDEOPIXELCROPR,     EBML_NONE },
508     { MATROSKA_ID_VIDEODISPLAYUNIT,    EBML_UINT,  0, 0, offsetof(MatroskaTrackVideo, display_unit), { .u= MATROSKA_VIDEO_DISPLAYUNIT_PIXELS } },
509     { MATROSKA_ID_VIDEOFLAGINTERLACED, EBML_UINT,  0, 0, offsetof(MatroskaTrackVideo, interlaced),  { .u = MATROSKA_VIDEO_INTERLACE_FLAG_UNDETERMINED } },
510     { MATROSKA_ID_VIDEOFIELDORDER,     EBML_UINT,  0, 0, offsetof(MatroskaTrackVideo, field_order), { .u = MATROSKA_VIDEO_FIELDORDER_UNDETERMINED } },
511     { MATROSKA_ID_VIDEOSTEREOMODE,     EBML_UINT,  0, 0, offsetof(MatroskaTrackVideo, stereo_mode), { .u = MATROSKA_VIDEO_STEREOMODE_TYPE_NB } },
512     { MATROSKA_ID_VIDEOASPECTRATIO,    EBML_NONE },
513     CHILD_OF(matroska_track)
514 };
515 
516 static EbmlSyntax matroska_track_audio[] = {
517     { MATROSKA_ID_AUDIOSAMPLINGFREQ,    EBML_FLOAT, 0, 0, offsetof(MatroskaTrackAudio, samplerate), { .f = 8000.0 } },
518     { MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, EBML_FLOAT, 0, 0, offsetof(MatroskaTrackAudio, out_samplerate) },
519     { MATROSKA_ID_AUDIOBITDEPTH,        EBML_UINT,  0, 0, offsetof(MatroskaTrackAudio, bitdepth) },
520     { MATROSKA_ID_AUDIOCHANNELS,        EBML_UINT,  0, 0, offsetof(MatroskaTrackAudio, channels),   { .u = 1 } },
521     CHILD_OF(matroska_track)
522 };
523 
524 static EbmlSyntax matroska_track_encoding_compression[] = {
525     { MATROSKA_ID_ENCODINGCOMPALGO,     EBML_UINT, 0, 0, offsetof(MatroskaTrackCompression, algo), { .u = MATROSKA_TRACK_ENCODING_COMP_ZLIB } },
526     { MATROSKA_ID_ENCODINGCOMPSETTINGS, EBML_BIN,  0, 0, offsetof(MatroskaTrackCompression, settings) },
527     CHILD_OF(matroska_track_encoding)
528 };
529 
530 static EbmlSyntax matroska_track_encoding_encryption[] = {
531     { MATROSKA_ID_ENCODINGENCALGO,        EBML_UINT, 0, 0, offsetof(MatroskaTrackEncryption,algo), {.u = 0} },
532     { MATROSKA_ID_ENCODINGENCKEYID,       EBML_BIN, 0, 0, offsetof(MatroskaTrackEncryption,key_id) },
533     { MATROSKA_ID_ENCODINGENCAESSETTINGS, EBML_NONE },
534     { MATROSKA_ID_ENCODINGSIGALGO,        EBML_NONE },
535     { MATROSKA_ID_ENCODINGSIGHASHALGO,    EBML_NONE },
536     { MATROSKA_ID_ENCODINGSIGKEYID,       EBML_NONE },
537     { MATROSKA_ID_ENCODINGSIGNATURE,      EBML_NONE },
538     CHILD_OF(matroska_track_encoding)
539 };
540 static EbmlSyntax matroska_track_encoding[] = {
541     { MATROSKA_ID_ENCODINGSCOPE,       EBML_UINT, 0, 0, offsetof(MatroskaTrackEncoding, scope),       { .u = 1 } },
542     { MATROSKA_ID_ENCODINGTYPE,        EBML_UINT, 0, 0, offsetof(MatroskaTrackEncoding, type),        { .u = 0 } },
543     { MATROSKA_ID_ENCODINGCOMPRESSION, EBML_NEST, 0, 0, offsetof(MatroskaTrackEncoding, compression), { .n = matroska_track_encoding_compression } },
544     { MATROSKA_ID_ENCODINGENCRYPTION,  EBML_NEST, 0, 0, offsetof(MatroskaTrackEncoding, encryption),  { .n = matroska_track_encoding_encryption } },
545     { MATROSKA_ID_ENCODINGORDER,       EBML_NONE },
546     CHILD_OF(matroska_track_encodings)
547 };
548 
549 static EbmlSyntax matroska_track_encodings[] = {
550     { MATROSKA_ID_TRACKCONTENTENCODING, EBML_NEST, 0, sizeof(MatroskaTrackEncoding), offsetof(MatroskaTrack, encodings), { .n = matroska_track_encoding } },
551     CHILD_OF(matroska_track)
552 };
553 
554 static EbmlSyntax matroska_track_plane[] = {
555     { MATROSKA_ID_TRACKPLANEUID,  EBML_UINT, 0, 0, offsetof(MatroskaTrackPlane,uid) },
556     { MATROSKA_ID_TRACKPLANETYPE, EBML_UINT, 0, 0, offsetof(MatroskaTrackPlane,type) },
557     CHILD_OF(matroska_track_combine_planes)
558 };
559 
560 static EbmlSyntax matroska_track_combine_planes[] = {
561     { MATROSKA_ID_TRACKPLANE, EBML_NEST, 0, sizeof(MatroskaTrackPlane), offsetof(MatroskaTrackOperation,combine_planes), {.n = matroska_track_plane} },
562     CHILD_OF(matroska_track_operation)
563 };
564 
565 static EbmlSyntax matroska_track_operation[] = {
566     { MATROSKA_ID_TRACKCOMBINEPLANES, EBML_NEST, 0, 0, 0, {.n = matroska_track_combine_planes} },
567     CHILD_OF(matroska_track)
568 };
569 
570 static EbmlSyntax matroska_track[] = {
571     { MATROSKA_ID_TRACKNUMBER,           EBML_UINT,  0, 0, offsetof(MatroskaTrack, num) },
572     { MATROSKA_ID_TRACKNAME,             EBML_UTF8,  0, 0, offsetof(MatroskaTrack, name) },
573     { MATROSKA_ID_TRACKUID,              EBML_UINT,  0, 0, offsetof(MatroskaTrack, uid) },
574     { MATROSKA_ID_TRACKTYPE,             EBML_UINT,  0, 0, offsetof(MatroskaTrack, type) },
575     { MATROSKA_ID_CODECID,               EBML_STR,   0, 0, offsetof(MatroskaTrack, codec_id) },
576     { MATROSKA_ID_CODECPRIVATE,          EBML_BIN,   0, 0, offsetof(MatroskaTrack, codec_priv) },
577     { MATROSKA_ID_CODECDELAY,            EBML_UINT,  0, 0, offsetof(MatroskaTrack, codec_delay),  { .u = 0 } },
578     { MATROSKA_ID_TRACKLANGUAGE,         EBML_STR,   0, 0, offsetof(MatroskaTrack, language),     { .s = "eng" } },
579     { MATROSKA_ID_TRACKDEFAULTDURATION,  EBML_UINT,  0, 0, offsetof(MatroskaTrack, default_duration) },
580     { MATROSKA_ID_TRACKTIMECODESCALE,    EBML_FLOAT, 0, 0, offsetof(MatroskaTrack, time_scale),   { .f = 1.0 } },
581     { MATROSKA_ID_TRACKFLAGCOMMENTARY,   EBML_UINT,  0, 0, offsetof(MatroskaTrack, flag_comment), { .u = 0 } },
582     { MATROSKA_ID_TRACKFLAGDEFAULT,      EBML_UINT,  0, 0, offsetof(MatroskaTrack, flag_default), { .u = 1 } },
583     { MATROSKA_ID_TRACKFLAGFORCED,       EBML_UINT,  0, 0, offsetof(MatroskaTrack, flag_forced),  { .u = 0 } },
584     { MATROSKA_ID_TRACKFLAGHEARINGIMPAIRED, EBML_UINT, 0, 0, offsetof(MatroskaTrack, flag_hearingimpaired), { .u = 0 } },
585     { MATROSKA_ID_TRACKFLAGVISUALIMPAIRED, EBML_UINT, 0, 0, offsetof(MatroskaTrack, flag_visualimpaired), { .u = 0 } },
586     { MATROSKA_ID_TRACKFLAGTEXTDESCRIPTIONS, EBML_UINT, 0, 0, offsetof(MatroskaTrack, flag_textdescriptions), { .u = 0 } },
587     { MATROSKA_ID_TRACKFLAGORIGINAL,     EBML_UINT,  1, 0, offsetof(MatroskaTrack, flag_original), {.u = 0 } },
588     { MATROSKA_ID_TRACKVIDEO,            EBML_NEST,  0, 0, offsetof(MatroskaTrack, video),        { .n = matroska_track_video } },
589     { MATROSKA_ID_TRACKAUDIO,            EBML_NEST,  0, 0, offsetof(MatroskaTrack, audio),        { .n = matroska_track_audio } },
590     { MATROSKA_ID_TRACKOPERATION,        EBML_NEST,  0, 0, offsetof(MatroskaTrack, operation),    { .n = matroska_track_operation } },
591     { MATROSKA_ID_TRACKCONTENTENCODINGS, EBML_NEST,  0, 0, 0,                                     { .n = matroska_track_encodings } },
592     { MATROSKA_ID_TRACKMAXBLKADDID,      EBML_UINT,  0, 0, offsetof(MatroskaTrack, max_block_additional_id), { .u = 0 } },
593     { MATROSKA_ID_SEEKPREROLL,           EBML_UINT,  0, 0, offsetof(MatroskaTrack, seek_preroll), { .u = 0 } },
594     { MATROSKA_ID_TRACKFLAGENABLED,      EBML_NONE },
595     { MATROSKA_ID_TRACKFLAGLACING,       EBML_NONE },
596     { MATROSKA_ID_CODECNAME,             EBML_NONE },
597     { MATROSKA_ID_CODECDECODEALL,        EBML_NONE },
598     { MATROSKA_ID_CODECINFOURL,          EBML_NONE },
599     { MATROSKA_ID_CODECDOWNLOADURL,      EBML_NONE },
600     { MATROSKA_ID_TRACKMINCACHE,         EBML_NONE },
601     { MATROSKA_ID_TRACKMAXCACHE,         EBML_NONE },
602     CHILD_OF(matroska_tracks)
603 };
604 
605 static EbmlSyntax matroska_tracks[] = {
606     { MATROSKA_ID_TRACKENTRY, EBML_NEST, 0, sizeof(MatroskaTrack), offsetof(MatroskaDemuxContext, tracks), { .n = matroska_track } },
607     CHILD_OF(matroska_segment)
608 };
609 
610 static EbmlSyntax matroska_attachment[] = {
611     { MATROSKA_ID_FILEUID,      EBML_UINT, 0, 0, offsetof(MatroskaAttachment, uid) },
612     { MATROSKA_ID_FILENAME,     EBML_UTF8, 0, 0, offsetof(MatroskaAttachment, filename) },
613     { MATROSKA_ID_FILEMIMETYPE, EBML_STR,  0, 0, offsetof(MatroskaAttachment, mime) },
614     { MATROSKA_ID_FILEDATA,     EBML_BIN,  0, 0, offsetof(MatroskaAttachment, bin) },
615     { MATROSKA_ID_FILEDESC,     EBML_UTF8, 0, 0, offsetof(MatroskaAttachment, description) },
616     CHILD_OF(matroska_attachments)
617 };
618 
619 static EbmlSyntax matroska_attachments[] = {
620     { MATROSKA_ID_ATTACHEDFILE, EBML_NEST, 0, sizeof(MatroskaAttachment), offsetof(MatroskaDemuxContext, attachments), { .n = matroska_attachment } },
621     CHILD_OF(matroska_segment)
622 };
623 
624 static EbmlSyntax matroska_chapter_display[] = {
625     { MATROSKA_ID_CHAPSTRING,  EBML_UTF8, 0, 0, offsetof(MatroskaChapter, title) },
626     { MATROSKA_ID_CHAPLANG,    EBML_NONE },
627     { MATROSKA_ID_CHAPCOUNTRY, EBML_NONE },
628     CHILD_OF(matroska_chapter_entry)
629 };
630 
631 static EbmlSyntax matroska_chapter_entry[] = {
632     { MATROSKA_ID_CHAPTERTIMESTART,   EBML_UINT, 0, 0, offsetof(MatroskaChapter, start), { .u = AV_NOPTS_VALUE } },
633     { MATROSKA_ID_CHAPTERTIMEEND,     EBML_UINT, 0, 0, offsetof(MatroskaChapter, end),   { .u = AV_NOPTS_VALUE } },
634     { MATROSKA_ID_CHAPTERUID,         EBML_UINT, 0, 0, offsetof(MatroskaChapter, uid) },
635     { MATROSKA_ID_CHAPTERDISPLAY,     EBML_NEST, 0, 0,                        0,         { .n = matroska_chapter_display } },
636     { MATROSKA_ID_CHAPTERFLAGHIDDEN,  EBML_NONE },
637     { MATROSKA_ID_CHAPTERFLAGENABLED, EBML_NONE },
638     { MATROSKA_ID_CHAPTERPHYSEQUIV,   EBML_NONE },
639     { MATROSKA_ID_CHAPTERATOM,        EBML_NONE },
640     CHILD_OF(matroska_chapter)
641 };
642 
643 static EbmlSyntax matroska_chapter[] = {
644     { MATROSKA_ID_CHAPTERATOM,        EBML_NEST, 0, sizeof(MatroskaChapter), offsetof(MatroskaDemuxContext, chapters), { .n = matroska_chapter_entry } },
645     { MATROSKA_ID_EDITIONUID,         EBML_NONE },
646     { MATROSKA_ID_EDITIONFLAGHIDDEN,  EBML_NONE },
647     { MATROSKA_ID_EDITIONFLAGDEFAULT, EBML_NONE },
648     { MATROSKA_ID_EDITIONFLAGORDERED, EBML_NONE },
649     CHILD_OF(matroska_chapters)
650 };
651 
652 static EbmlSyntax matroska_chapters[] = {
653     { MATROSKA_ID_EDITIONENTRY, EBML_NEST, 0, 0, 0, { .n = matroska_chapter } },
654     CHILD_OF(matroska_segment)
655 };
656 
657 static EbmlSyntax matroska_index_pos[] = {
658     { MATROSKA_ID_CUETRACK,           EBML_UINT, 0, 0, offsetof(MatroskaIndexPos, track) },
659     { MATROSKA_ID_CUECLUSTERPOSITION, EBML_UINT, 0, 0, offsetof(MatroskaIndexPos, pos) },
660     { MATROSKA_ID_CUERELATIVEPOSITION,EBML_NONE },
661     { MATROSKA_ID_CUEDURATION,        EBML_NONE },
662     { MATROSKA_ID_CUEBLOCKNUMBER,     EBML_NONE },
663     CHILD_OF(matroska_index_entry)
664 };
665 
666 static EbmlSyntax matroska_index_entry[] = {
667     { MATROSKA_ID_CUETIME,          EBML_UINT, 0, 0,                        offsetof(MatroskaIndex, time) },
668     { MATROSKA_ID_CUETRACKPOSITION, EBML_NEST, 0, sizeof(MatroskaIndexPos), offsetof(MatroskaIndex, pos), { .n = matroska_index_pos } },
669     CHILD_OF(matroska_index)
670 };
671 
672 static EbmlSyntax matroska_index[] = {
673     { MATROSKA_ID_POINTENTRY, EBML_NEST, 0, sizeof(MatroskaIndex), offsetof(MatroskaDemuxContext, index), { .n = matroska_index_entry } },
674     CHILD_OF(matroska_segment)
675 };
676 
677 static EbmlSyntax matroska_simpletag[] = {
678     { MATROSKA_ID_TAGNAME,        EBML_UTF8, 0, 0,                   offsetof(MatroskaTag, name) },
679     { MATROSKA_ID_TAGSTRING,      EBML_UTF8, 0, 0,                   offsetof(MatroskaTag, string) },
680     { MATROSKA_ID_TAGLANG,        EBML_STR,  0, 0,                   offsetof(MatroskaTag, lang), { .s = "und" } },
681     { MATROSKA_ID_TAGDEFAULT,     EBML_UINT, 0, 0,                   offsetof(MatroskaTag, def) },
682     { MATROSKA_ID_TAGDEFAULT_BUG, EBML_UINT, 0, 0,                   offsetof(MatroskaTag, def) },
683     { MATROSKA_ID_SIMPLETAG,      EBML_NEST, 0, sizeof(MatroskaTag), offsetof(MatroskaTag, sub),  { .n = matroska_simpletag } },
684     CHILD_OF(matroska_tag)
685 };
686 
687 static EbmlSyntax matroska_tagtargets[] = {
688     { MATROSKA_ID_TAGTARGETS_TYPE,       EBML_STR,  0, 0, offsetof(MatroskaTagTarget, type) },
689     { MATROSKA_ID_TAGTARGETS_TYPEVALUE,  EBML_UINT, 0, 0, offsetof(MatroskaTagTarget, typevalue),  { .u = 50 } },
690     { MATROSKA_ID_TAGTARGETS_TRACKUID,   EBML_UINT, 0, 0, offsetof(MatroskaTagTarget, trackuid),   { .u = 0 } },
691     { MATROSKA_ID_TAGTARGETS_CHAPTERUID, EBML_UINT, 0, 0, offsetof(MatroskaTagTarget, chapteruid), { .u = 0 } },
692     { MATROSKA_ID_TAGTARGETS_ATTACHUID,  EBML_UINT, 0, 0, offsetof(MatroskaTagTarget, attachuid),  { .u = 0 } },
693     CHILD_OF(matroska_tag)
694 };
695 
696 static EbmlSyntax matroska_tag[] = {
697     { MATROSKA_ID_SIMPLETAG,  EBML_NEST, 0, sizeof(MatroskaTag), offsetof(MatroskaTags, tag),    { .n = matroska_simpletag } },
698     { MATROSKA_ID_TAGTARGETS, EBML_NEST, 0, 0,                   offsetof(MatroskaTags, target), { .n = matroska_tagtargets } },
699     CHILD_OF(matroska_tags)
700 };
701 
702 static EbmlSyntax matroska_tags[] = {
703     { MATROSKA_ID_TAG, EBML_NEST, 0, sizeof(MatroskaTags), offsetof(MatroskaDemuxContext, tags), { .n = matroska_tag } },
704     CHILD_OF(matroska_segment)
705 };
706 
707 static EbmlSyntax matroska_seekhead_entry[] = {
708     { MATROSKA_ID_SEEKID,       EBML_UINT, 0, 0, offsetof(MatroskaSeekhead, id) },
709     { MATROSKA_ID_SEEKPOSITION, EBML_UINT, 0, 0, offsetof(MatroskaSeekhead, pos), { .u = -1 } },
710     CHILD_OF(matroska_seekhead)
711 };
712 
713 static EbmlSyntax matroska_seekhead[] = {
714     { MATROSKA_ID_SEEKENTRY, EBML_NEST, 0, sizeof(MatroskaSeekhead), offsetof(MatroskaDemuxContext, seekhead), { .n = matroska_seekhead_entry } },
715     CHILD_OF(matroska_segment)
716 };
717 
718 static EbmlSyntax matroska_segment[] = {
719     { MATROSKA_ID_CLUSTER,     EBML_STOP },
720     { MATROSKA_ID_INFO,        EBML_LEVEL1, 0, 0, 0, { .n = matroska_info } },
721     { MATROSKA_ID_TRACKS,      EBML_LEVEL1, 0, 0, 0, { .n = matroska_tracks } },
722     { MATROSKA_ID_ATTACHMENTS, EBML_LEVEL1, 0, 0, 0, { .n = matroska_attachments } },
723     { MATROSKA_ID_CHAPTERS,    EBML_LEVEL1, 0, 0, 0, { .n = matroska_chapters } },
724     { MATROSKA_ID_CUES,        EBML_LEVEL1, 0, 0, 0, { .n = matroska_index } },
725     { MATROSKA_ID_TAGS,        EBML_LEVEL1, 0, 0, 0, { .n = matroska_tags } },
726     { MATROSKA_ID_SEEKHEAD,    EBML_LEVEL1, 0, 0, 0, { .n = matroska_seekhead } },
727     { 0 }   /* We don't want to go back to level 0, so don't add the parent. */
728 };
729 
730 static EbmlSyntax matroska_segments[] = {
731     { MATROSKA_ID_SEGMENT, EBML_NEST, 0, 0, 0, { .n = matroska_segment } },
732     { 0 }
733 };
734 
735 static EbmlSyntax matroska_blockmore[] = {
736     { MATROSKA_ID_BLOCKADDID,      EBML_UINT, 0, 0, offsetof(MatroskaBlock,additional_id), { .u = 1 } },
737     { MATROSKA_ID_BLOCKADDITIONAL, EBML_BIN,  0, 0, offsetof(MatroskaBlock,additional) },
738     CHILD_OF(matroska_blockadditions)
739 };
740 
741 static EbmlSyntax matroska_blockadditions[] = {
742     { MATROSKA_ID_BLOCKMORE, EBML_NEST, 0, 0, 0, {.n = matroska_blockmore} },
743     CHILD_OF(matroska_blockgroup)
744 };
745 
746 static EbmlSyntax matroska_blockgroup[] = {
747     { MATROSKA_ID_BLOCK,          EBML_BIN,  0, 0, offsetof(MatroskaBlock, bin) },
748     { MATROSKA_ID_BLOCKADDITIONS, EBML_NEST, 0, 0, 0, { .n = matroska_blockadditions} },
749     { MATROSKA_ID_BLOCKDURATION,  EBML_UINT, 0, 0, offsetof(MatroskaBlock, duration) },
750     { MATROSKA_ID_DISCARDPADDING, EBML_SINT, 0, 0, offsetof(MatroskaBlock, discard_padding) },
751     { MATROSKA_ID_BLOCKREFERENCE, EBML_SINT, 1, 0, offsetof(MatroskaBlock, reference) },
752     { MATROSKA_ID_CODECSTATE,     EBML_NONE },
753     {                          1, EBML_UINT, 0, 0, offsetof(MatroskaBlock, non_simple), { .u = 1 } },
754     CHILD_OF(matroska_cluster_parsing)
755 };
756 
757 // The following array contains SimpleBlock and BlockGroup twice
758 // in order to reuse the other values for matroska_cluster_enter.
759 static EbmlSyntax matroska_cluster_parsing[] = {
760     { MATROSKA_ID_SIMPLEBLOCK,     EBML_BIN,  0, 0, offsetof(MatroskaBlock, bin) },
761     { MATROSKA_ID_BLOCKGROUP,      EBML_NEST, 0, 0, 0, { .n = matroska_blockgroup } },
762     { MATROSKA_ID_CLUSTERTIMECODE, EBML_UINT, 0, 0, offsetof(MatroskaCluster, timecode) },
763     { MATROSKA_ID_SIMPLEBLOCK,     EBML_STOP },
764     { MATROSKA_ID_BLOCKGROUP,      EBML_STOP },
765     { MATROSKA_ID_CLUSTERPOSITION, EBML_NONE },
766     { MATROSKA_ID_CLUSTERPREVSIZE, EBML_NONE },
767     CHILD_OF(matroska_segment)
768 };
769 
770 static EbmlSyntax matroska_cluster_enter[] = {
771     { MATROSKA_ID_CLUSTER,     EBML_NEST, 0, 0, 0, { .n = &matroska_cluster_parsing[2] } },
772     { 0 }
773 };
774 #undef CHILD_OF
775 
776 static const CodecMime mkv_image_mime_tags[] = {
777     {"image/gif"                  , AV_CODEC_ID_GIF},
778     {"image/jpeg"                 , AV_CODEC_ID_MJPEG},
779     {"image/png"                  , AV_CODEC_ID_PNG},
780     {"image/tiff"                 , AV_CODEC_ID_TIFF},
781 
782     {""                           , AV_CODEC_ID_NONE}
783 };
784 
785 static const CodecMime mkv_mime_tags[] = {
786     {"text/plain"                 , AV_CODEC_ID_TEXT},
787     {"application/x-truetype-font", AV_CODEC_ID_TTF},
788     {"application/x-font"         , AV_CODEC_ID_TTF},
789     {"application/vnd.ms-opentype", AV_CODEC_ID_OTF},
790     {"binary"                     , AV_CODEC_ID_BIN_DATA},
791 
792     {""                           , AV_CODEC_ID_NONE}
793 };
794 
795 static const char *const matroska_doctypes[] = { "matroska", "webm" };
796 
797 static int matroska_read_close(AVFormatContext *s);
798 
799 /*
800  * This function prepares the status for parsing of level 1 elements.
801  */
matroska_reset_status(MatroskaDemuxContext * matroska,uint32_t id,int64_t position)802 static int matroska_reset_status(MatroskaDemuxContext *matroska,
803                                  uint32_t id, int64_t position)
804 {
805     int64_t err = 0;
806     if (position >= 0) {
807         err = avio_seek(matroska->ctx->pb, position, SEEK_SET);
808         if (err > 0)
809             err = 0;
810     } else
811         position = avio_tell(matroska->ctx->pb);
812 
813     matroska->current_id    = id;
814     matroska->num_levels    = 1;
815     matroska->unknown_count = 0;
816     matroska->resync_pos    = position;
817     if (id)
818         matroska->resync_pos -= (av_log2(id) + 7) / 8;
819 
820     return err;
821 }
822 
matroska_resync(MatroskaDemuxContext * matroska,int64_t last_pos)823 static int matroska_resync(MatroskaDemuxContext *matroska, int64_t last_pos)
824 {
825     AVIOContext *pb = matroska->ctx->pb;
826     uint32_t id;
827 
828     /* Try to seek to the last position to resync from. If this doesn't work,
829      * we resync from the earliest position available: The start of the buffer. */
830     if (last_pos < avio_tell(pb) && avio_seek(pb, last_pos + 1, SEEK_SET) < 0) {
831         av_log(matroska->ctx, AV_LOG_WARNING,
832                "Seek to desired resync point failed. Seeking to "
833                "earliest point available instead.\n");
834         avio_seek(pb, FFMAX(avio_tell(pb) + (pb->buffer - pb->buf_ptr),
835                             last_pos + 1), SEEK_SET);
836     }
837 
838     id = avio_rb32(pb);
839 
840     // try to find a toplevel element
841     while (!avio_feof(pb)) {
842         if (id == MATROSKA_ID_INFO     || id == MATROSKA_ID_TRACKS      ||
843             id == MATROSKA_ID_CUES     || id == MATROSKA_ID_TAGS        ||
844             id == MATROSKA_ID_SEEKHEAD || id == MATROSKA_ID_ATTACHMENTS ||
845             id == MATROSKA_ID_CLUSTER  || id == MATROSKA_ID_CHAPTERS) {
846             /* Prepare the context for parsing of a level 1 element. */
847             matroska_reset_status(matroska, id, -1);
848             /* Given that we are here means that an error has occurred,
849              * so treat the segment as unknown length in order not to
850              * discard valid data that happens to be beyond the designated
851              * end of the segment. */
852             matroska->levels[0].length = EBML_UNKNOWN_LENGTH;
853             return 0;
854         }
855         id = (id << 8) | avio_r8(pb);
856     }
857 
858     matroska->done = 1;
859     return pb->error ? pb->error : AVERROR_EOF;
860 }
861 
862 /*
863  * Read: an "EBML number", which is defined as a variable-length
864  * array of bytes. The first byte indicates the length by giving a
865  * number of 0-bits followed by a one. The position of the first
866  * "one" bit inside the first byte indicates the length of this
867  * number.
868  * Returns: number of bytes read, < 0 on error
869  */
ebml_read_num(MatroskaDemuxContext * matroska,AVIOContext * pb,int max_size,uint64_t * number,int eof_forbidden)870 static int ebml_read_num(MatroskaDemuxContext *matroska, AVIOContext *pb,
871                          int max_size, uint64_t *number, int eof_forbidden)
872 {
873     int read, n = 1;
874     uint64_t total;
875     int64_t pos;
876 
877     /* The first byte tells us the length in bytes - except when it is zero. */
878     total = avio_r8(pb);
879     if (pb->eof_reached)
880         goto err;
881 
882     /* get the length of the EBML number */
883     read = 8 - ff_log2_tab[total];
884 
885     if (!total || read > max_size) {
886         pos = avio_tell(pb) - 1;
887         if (!total) {
888             av_log(matroska->ctx, AV_LOG_ERROR,
889                    "0x00 at pos %"PRId64" (0x%"PRIx64") invalid as first byte "
890                    "of an EBML number\n", pos, pos);
891         } else {
892             av_log(matroska->ctx, AV_LOG_ERROR,
893                    "Length %d indicated by an EBML number's first byte 0x%02x "
894                    "at pos %"PRId64" (0x%"PRIx64") exceeds max length %d.\n",
895                    read, (uint8_t) total, pos, pos, max_size);
896         }
897         return AVERROR_INVALIDDATA;
898     }
899 
900     /* read out length */
901     total ^= 1 << ff_log2_tab[total];
902     while (n++ < read)
903         total = (total << 8) | avio_r8(pb);
904 
905     if (pb->eof_reached) {
906         eof_forbidden = 1;
907         goto err;
908     }
909 
910     *number = total;
911 
912     return read;
913 
914 err:
915     pos = avio_tell(pb);
916     if (pb->error) {
917         av_log(matroska->ctx, AV_LOG_ERROR,
918                "Read error at pos. %"PRIu64" (0x%"PRIx64")\n",
919                pos, pos);
920         return pb->error;
921     }
922     if (eof_forbidden) {
923         av_log(matroska->ctx, AV_LOG_ERROR, "File ended prematurely "
924                "at pos. %"PRIu64" (0x%"PRIx64")\n", pos, pos);
925         return AVERROR(EIO);
926     }
927     return AVERROR_EOF;
928 }
929 
930 /**
931  * Read a EBML length value.
932  * This needs special handling for the "unknown length" case which has multiple
933  * encodings.
934  */
ebml_read_length(MatroskaDemuxContext * matroska,AVIOContext * pb,uint64_t * number)935 static int ebml_read_length(MatroskaDemuxContext *matroska, AVIOContext *pb,
936                             uint64_t *number)
937 {
938     int res = ebml_read_num(matroska, pb, 8, number, 1);
939     if (res > 0 && *number + 1 == 1ULL << (7 * res))
940         *number = EBML_UNKNOWN_LENGTH;
941     return res;
942 }
943 
944 /*
945  * Read the next element as an unsigned int.
946  * Returns NEEDS_CHECKING unless size == 0.
947  */
ebml_read_uint(AVIOContext * pb,int size,uint64_t default_value,uint64_t * num)948 static int ebml_read_uint(AVIOContext *pb, int size,
949                           uint64_t default_value, uint64_t *num)
950 {
951     int n = 0;
952 
953     if (size == 0) {
954         *num = default_value;
955         return 0;
956     }
957     /* big-endian ordering; build up number */
958     *num = 0;
959     while (n++ < size)
960         *num = (*num << 8) | avio_r8(pb);
961 
962     return NEEDS_CHECKING;
963 }
964 
965 /*
966  * Read the next element as a signed int.
967  * Returns NEEDS_CHECKING unless size == 0.
968  */
ebml_read_sint(AVIOContext * pb,int size,int64_t default_value,int64_t * num)969 static int ebml_read_sint(AVIOContext *pb, int size,
970                           int64_t default_value, int64_t *num)
971 {
972     int n = 1;
973 
974     if (size == 0) {
975         *num = default_value;
976         return 0;
977     } else {
978         *num = sign_extend(avio_r8(pb), 8);
979 
980         /* big-endian ordering; build up number */
981         while (n++ < size)
982             *num = ((uint64_t)*num << 8) | avio_r8(pb);
983     }
984 
985     return NEEDS_CHECKING;
986 }
987 
988 /*
989  * Read the next element as a float.
990  * Returns 0 if size == 0, NEEDS_CHECKING or < 0 on obvious failure.
991  */
ebml_read_float(AVIOContext * pb,int size,double default_value,double * num)992 static int ebml_read_float(AVIOContext *pb, int size,
993                            double default_value, double *num)
994 {
995     if (size == 0) {
996         *num = default_value;
997         return 0;
998     } else if (size == 4) {
999         *num = av_int2float(avio_rb32(pb));
1000     } else if (size == 8) {
1001         *num = av_int2double(avio_rb64(pb));
1002     } else
1003         return AVERROR_INVALIDDATA;
1004 
1005     return NEEDS_CHECKING;
1006 }
1007 
1008 /*
1009  * Read the next element as an ASCII string.
1010  * 0 is success, < 0 or NEEDS_CHECKING is failure.
1011  */
ebml_read_ascii(AVIOContext * pb,int size,const char * default_value,char ** str)1012 static int ebml_read_ascii(AVIOContext *pb, int size,
1013                            const char *default_value, char **str)
1014 {
1015     char *res;
1016     int ret;
1017 
1018     if (size == 0 && default_value) {
1019         res = av_strdup(default_value);
1020         if (!res)
1021             return AVERROR(ENOMEM);
1022     } else {
1023         /* EBML strings are usually not 0-terminated, so we allocate one
1024          * byte more, read the string and NUL-terminate it ourselves. */
1025         if (!(res = av_malloc(size + 1)))
1026             return AVERROR(ENOMEM);
1027         if ((ret = avio_read(pb, (uint8_t *) res, size)) != size) {
1028             av_free(res);
1029             return ret < 0 ? ret : NEEDS_CHECKING;
1030         }
1031         (res)[size] = '\0';
1032     }
1033     av_free(*str);
1034     *str = res;
1035 
1036     return 0;
1037 }
1038 
1039 /*
1040  * Read the next element as binary data.
1041  * 0 is success, < 0 or NEEDS_CHECKING is failure.
1042  */
ebml_read_binary(AVIOContext * pb,int length,int64_t pos,EbmlBin * bin)1043 static int ebml_read_binary(AVIOContext *pb, int length,
1044                             int64_t pos, EbmlBin *bin)
1045 {
1046     int ret;
1047 
1048     ret = av_buffer_realloc(&bin->buf, length + AV_INPUT_BUFFER_PADDING_SIZE);
1049     if (ret < 0)
1050         return ret;
1051     memset(bin->buf->data + length, 0, AV_INPUT_BUFFER_PADDING_SIZE);
1052 
1053     bin->data = bin->buf->data;
1054     bin->size = length;
1055     bin->pos  = pos;
1056     if ((ret = avio_read(pb, bin->data, length)) != length) {
1057         av_buffer_unref(&bin->buf);
1058         bin->data = NULL;
1059         bin->size = 0;
1060         return ret < 0 ? ret : NEEDS_CHECKING;
1061     }
1062 
1063     return 0;
1064 }
1065 
1066 /*
1067  * Read the next element, but only the header. The contents
1068  * are supposed to be sub-elements which can be read separately.
1069  * 0 is success, < 0 is failure.
1070  */
ebml_read_master(MatroskaDemuxContext * matroska,uint64_t length,int64_t pos)1071 static int ebml_read_master(MatroskaDemuxContext *matroska,
1072                             uint64_t length, int64_t pos)
1073 {
1074     MatroskaLevel *level;
1075 
1076     if (matroska->num_levels >= EBML_MAX_DEPTH) {
1077         av_log(matroska->ctx, AV_LOG_ERROR,
1078                "File moves beyond max. allowed depth (%d)\n", EBML_MAX_DEPTH);
1079         return AVERROR(ENOSYS);
1080     }
1081 
1082     level         = &matroska->levels[matroska->num_levels++];
1083     level->start  = pos;
1084     level->length = length;
1085 
1086     return 0;
1087 }
1088 
1089 /*
1090  * Read a signed "EBML number"
1091  * Return: number of bytes processed, < 0 on error
1092  */
matroska_ebmlnum_sint(MatroskaDemuxContext * matroska,AVIOContext * pb,int64_t * num)1093 static int matroska_ebmlnum_sint(MatroskaDemuxContext *matroska,
1094                                  AVIOContext *pb, int64_t *num)
1095 {
1096     uint64_t unum;
1097     int res;
1098 
1099     /* read as unsigned number first */
1100     if ((res = ebml_read_num(matroska, pb, 8, &unum, 1)) < 0)
1101         return res;
1102 
1103     /* make signed (weird way) */
1104     *num = unum - ((1LL << (7 * res - 1)) - 1);
1105 
1106     return res;
1107 }
1108 
1109 static int ebml_parse(MatroskaDemuxContext *matroska,
1110                       EbmlSyntax *syntax, void *data);
1111 
ebml_parse_id(EbmlSyntax * syntax,uint32_t id)1112 static EbmlSyntax *ebml_parse_id(EbmlSyntax *syntax, uint32_t id)
1113 {
1114     int i;
1115 
1116     // Whoever touches this should be aware of the duplication
1117     // existing in matroska_cluster_parsing.
1118     for (i = 0; syntax[i].id; i++)
1119         if (id == syntax[i].id)
1120             break;
1121 
1122     return &syntax[i];
1123 }
1124 
ebml_parse_nest(MatroskaDemuxContext * matroska,EbmlSyntax * syntax,void * data)1125 static int ebml_parse_nest(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
1126                            void *data)
1127 {
1128     int res;
1129 
1130     if (data) {
1131         for (int i = 0; syntax[i].id; i++) {
1132             void *dst = (char *)data + syntax[i].data_offset;
1133             switch (syntax[i].type) {
1134             case EBML_UINT:
1135                 *(uint64_t *)dst = syntax[i].def.u;
1136                 break;
1137             case EBML_SINT:
1138                 *(int64_t *) dst = syntax[i].def.i;
1139                 break;
1140             case EBML_FLOAT:
1141                 *(double *)  dst = syntax[i].def.f;
1142                 break;
1143             case EBML_STR:
1144             case EBML_UTF8:
1145                 // the default may be NULL
1146                 if (syntax[i].def.s) {
1147                     *(char**)dst = av_strdup(syntax[i].def.s);
1148                     if (!*(char**)dst)
1149                         return AVERROR(ENOMEM);
1150                 }
1151                 break;
1152             }
1153         }
1154 
1155         if (!matroska->levels[matroska->num_levels - 1].length) {
1156             matroska->num_levels--;
1157             return 0;
1158         }
1159     }
1160 
1161     do {
1162         res = ebml_parse(matroska, syntax, data);
1163     } while (!res);
1164 
1165     return res == LEVEL_ENDED ? 0 : res;
1166 }
1167 
is_ebml_id_valid(uint32_t id)1168 static int is_ebml_id_valid(uint32_t id)
1169 {
1170     // Due to endian nonsense in Matroska, the highest byte with any bits set
1171     // will contain the leading length bit. This bit in turn identifies the
1172     // total byte length of the element by its position within the byte.
1173     unsigned int bits = av_log2(id);
1174     return id && (bits + 7) / 8 ==  (8 - bits % 8);
1175 }
1176 
1177 /*
1178  * Allocate and return the entry for the level1 element with the given ID. If
1179  * an entry already exists, return the existing entry.
1180  */
matroska_find_level1_elem(MatroskaDemuxContext * matroska,uint32_t id,int64_t pos)1181 static MatroskaLevel1Element *matroska_find_level1_elem(MatroskaDemuxContext *matroska,
1182                                                         uint32_t id, int64_t pos)
1183 {
1184     int i;
1185     MatroskaLevel1Element *elem;
1186 
1187     if (!is_ebml_id_valid(id))
1188         return NULL;
1189 
1190     // Some files link to all clusters; useless.
1191     if (id == MATROSKA_ID_CLUSTER)
1192         return NULL;
1193 
1194     // There can be multiple SeekHeads and Tags.
1195     for (i = 0; i < matroska->num_level1_elems; i++) {
1196         if (matroska->level1_elems[i].id == id) {
1197             if (matroska->level1_elems[i].pos == pos ||
1198                 id != MATROSKA_ID_SEEKHEAD && id != MATROSKA_ID_TAGS)
1199                 return &matroska->level1_elems[i];
1200         }
1201     }
1202 
1203     // Only a completely broken file would have more elements.
1204     if (matroska->num_level1_elems >= FF_ARRAY_ELEMS(matroska->level1_elems)) {
1205         av_log(matroska->ctx, AV_LOG_ERROR, "Too many level1 elements.\n");
1206         return NULL;
1207     }
1208 
1209     elem = &matroska->level1_elems[matroska->num_level1_elems++];
1210     *elem = (MatroskaLevel1Element){.id = id};
1211 
1212     return elem;
1213 }
1214 
ebml_parse(MatroskaDemuxContext * matroska,EbmlSyntax * syntax,void * data)1215 static int ebml_parse(MatroskaDemuxContext *matroska,
1216                       EbmlSyntax *syntax, void *data)
1217 {
1218     static const uint64_t max_lengths[EBML_TYPE_COUNT] = {
1219         // Forbid unknown-length EBML_NONE elements.
1220         [EBML_NONE]  = EBML_UNKNOWN_LENGTH - 1,
1221         [EBML_UINT]  = 8,
1222         [EBML_SINT]  = 8,
1223         [EBML_FLOAT] = 8,
1224         // max. 16 MB for strings
1225         [EBML_STR]   = 0x1000000,
1226         [EBML_UTF8]  = 0x1000000,
1227         // max. 256 MB for binary data
1228         [EBML_BIN]   = 0x10000000,
1229         // no limits for anything else
1230     };
1231     AVIOContext *pb = matroska->ctx->pb;
1232     uint32_t id;
1233     uint64_t length;
1234     int64_t pos = avio_tell(pb), pos_alt;
1235     int res, update_pos = 1, level_check;
1236     MatroskaLevel1Element *level1_elem;
1237     MatroskaLevel *level = matroska->num_levels ? &matroska->levels[matroska->num_levels - 1] : NULL;
1238 
1239     if (!matroska->current_id) {
1240         uint64_t id;
1241         res = ebml_read_num(matroska, pb, 4, &id, 0);
1242         if (res < 0) {
1243             if (pb->eof_reached && res == AVERROR_EOF) {
1244                 if (matroska->is_live)
1245                     // in live mode, finish parsing if EOF is reached.
1246                     return 1;
1247                 if (level && pos == avio_tell(pb)) {
1248                     if (level->length == EBML_UNKNOWN_LENGTH) {
1249                         // Unknown-length levels automatically end at EOF.
1250                         matroska->num_levels--;
1251                         return LEVEL_ENDED;
1252                     } else {
1253                         av_log(matroska->ctx, AV_LOG_ERROR, "File ended prematurely "
1254                                "at pos. %"PRIu64" (0x%"PRIx64")\n", pos, pos);
1255                     }
1256                 }
1257             }
1258             return res;
1259         }
1260         matroska->current_id = id | 1 << 7 * res;
1261         pos_alt = pos + res;
1262     } else {
1263         pos_alt = pos;
1264         pos    -= (av_log2(matroska->current_id) + 7) / 8;
1265     }
1266 
1267     id = matroska->current_id;
1268 
1269     syntax = ebml_parse_id(syntax, id);
1270     if (!syntax->id && id != EBML_ID_VOID && id != EBML_ID_CRC32) {
1271         if (level && level->length == EBML_UNKNOWN_LENGTH) {
1272             // Unknown-length levels end when an element from an upper level
1273             // in the hierarchy is encountered.
1274             while (syntax->def.n) {
1275                 syntax = ebml_parse_id(syntax->def.n, id);
1276                 if (syntax->id) {
1277                     matroska->num_levels--;
1278                     return LEVEL_ENDED;
1279                 }
1280             };
1281         }
1282 
1283         av_log(matroska->ctx, AV_LOG_DEBUG, "Unknown entry 0x%"PRIX32" at pos. "
1284                                             "%"PRId64"\n", id, pos);
1285         update_pos = 0; /* Don't update resync_pos as an error might have happened. */
1286     }
1287 
1288     if (data) {
1289         data = (char *) data + syntax->data_offset;
1290         if (syntax->list_elem_size) {
1291             EbmlList *list = data;
1292             void *newelem;
1293 
1294             if ((unsigned)list->nb_elem + 1 >= UINT_MAX / syntax->list_elem_size)
1295                 return AVERROR(ENOMEM);
1296             newelem = av_fast_realloc(list->elem,
1297                                       &list->alloc_elem_size,
1298                                       (list->nb_elem + 1) * syntax->list_elem_size);
1299             if (!newelem)
1300                 return AVERROR(ENOMEM);
1301             list->elem = newelem;
1302             data = (char *) list->elem + list->nb_elem * syntax->list_elem_size;
1303             memset(data, 0, syntax->list_elem_size);
1304             list->nb_elem++;
1305         }
1306     }
1307 
1308     if (syntax->type != EBML_STOP) {
1309         matroska->current_id = 0;
1310         if ((res = ebml_read_length(matroska, pb, &length)) < 0)
1311             return res;
1312 
1313         pos_alt += res;
1314 
1315         if (matroska->num_levels > 0) {
1316             if (length != EBML_UNKNOWN_LENGTH &&
1317                 level->length != EBML_UNKNOWN_LENGTH) {
1318                 uint64_t elem_end = pos_alt + length,
1319                         level_end = level->start + level->length;
1320 
1321                 if (elem_end < level_end) {
1322                     level_check = 0;
1323                 } else if (elem_end == level_end) {
1324                     level_check = LEVEL_ENDED;
1325                 } else {
1326                     av_log(matroska->ctx, AV_LOG_ERROR,
1327                            "Element at 0x%"PRIx64" ending at 0x%"PRIx64" exceeds "
1328                            "containing master element ending at 0x%"PRIx64"\n",
1329                            pos, elem_end, level_end);
1330                     return AVERROR_INVALIDDATA;
1331                 }
1332             } else if (length != EBML_UNKNOWN_LENGTH) {
1333                 level_check = 0;
1334             } else if (level->length != EBML_UNKNOWN_LENGTH) {
1335                 av_log(matroska->ctx, AV_LOG_ERROR, "Unknown-sized element "
1336                        "at 0x%"PRIx64" inside parent with finite size\n", pos);
1337                 return AVERROR_INVALIDDATA;
1338             } else {
1339                 level_check = 0;
1340                 if (id != MATROSKA_ID_CLUSTER && (syntax->type == EBML_LEVEL1
1341                                               ||  syntax->type == EBML_NEST)) {
1342                     // According to the current specifications only clusters and
1343                     // segments are allowed to be unknown-length. We also accept
1344                     // other unknown-length master elements.
1345                     av_log(matroska->ctx, AV_LOG_WARNING,
1346                            "Found unknown-length element 0x%"PRIX32" other than "
1347                            "a cluster at 0x%"PRIx64". Spec-incompliant, but "
1348                            "parsing will nevertheless be attempted.\n", id, pos);
1349                     update_pos = -1;
1350                 }
1351             }
1352         } else
1353             level_check = 0;
1354 
1355         if (max_lengths[syntax->type] && length > max_lengths[syntax->type]) {
1356             if (length != EBML_UNKNOWN_LENGTH) {
1357                 av_log(matroska->ctx, AV_LOG_ERROR,
1358                        "Invalid length 0x%"PRIx64" > 0x%"PRIx64" for element "
1359                        "with ID 0x%"PRIX32" at 0x%"PRIx64"\n",
1360                        length, max_lengths[syntax->type], id, pos);
1361             } else if (syntax->type != EBML_NONE) {
1362                 av_log(matroska->ctx, AV_LOG_ERROR,
1363                        "Element with ID 0x%"PRIX32" at pos. 0x%"PRIx64" has "
1364                        "unknown length, yet the length of an element of its "
1365                        "type must be known.\n", id, pos);
1366             } else {
1367                 av_log(matroska->ctx, AV_LOG_ERROR,
1368                        "Found unknown-length element with ID 0x%"PRIX32" at "
1369                        "pos. 0x%"PRIx64" for which no syntax for parsing is "
1370                        "available.\n", id, pos);
1371             }
1372             return AVERROR_INVALIDDATA;
1373         }
1374 
1375         if (!(pb->seekable & AVIO_SEEKABLE_NORMAL)) {
1376             // Loosing sync will likely manifest itself as encountering unknown
1377             // elements which are not reliably distinguishable from elements
1378             // belonging to future extensions of the format.
1379             // We use a heuristic to detect such situations: If the current
1380             // element is not expected at the current syntax level and there
1381             // were only a few unknown elements in a row, then the element is
1382             // skipped or considered defective based upon the length of the
1383             // current element (i.e. how much would be skipped); if there were
1384             // more than a few skipped elements in a row and skipping the current
1385             // element would lead us more than SKIP_THRESHOLD away from the last
1386             // known good position, then it is inferred that an error occurred.
1387             // The dependency on the number of unknown elements in a row exists
1388             // because the distance to the last known good position is
1389             // automatically big if the last parsed element was big.
1390             // In both cases, each unknown element is considered equivalent to
1391             // UNKNOWN_EQUIV of skipped bytes for the check.
1392             // The whole check is only done for non-seekable output, because
1393             // in this situation skipped data can't simply be rechecked later.
1394             // This is especially important when using unkown length elements
1395             // as the check for whether a child exceeds its containing master
1396             // element is not effective in this situation.
1397             if (update_pos) {
1398                 matroska->unknown_count = 0;
1399             } else {
1400                 int64_t dist = length + UNKNOWN_EQUIV * matroska->unknown_count++;
1401 
1402                 if (matroska->unknown_count > 3)
1403                     dist += pos_alt - matroska->resync_pos;
1404 
1405                 if (dist > SKIP_THRESHOLD) {
1406                     av_log(matroska->ctx, AV_LOG_ERROR,
1407                            "Unknown element %"PRIX32" at pos. 0x%"PRIx64" with "
1408                            "length 0x%"PRIx64" considered as invalid data. Last "
1409                            "known good position 0x%"PRIx64", %d unknown elements"
1410                            " in a row\n", id, pos, length, matroska->resync_pos,
1411                            matroska->unknown_count);
1412                     return AVERROR_INVALIDDATA;
1413                 }
1414             }
1415         }
1416 
1417         if (update_pos > 0) {
1418             // We have found an element that is allowed at this place
1419             // in the hierarchy and it passed all checks, so treat the beginning
1420             // of the element as the "last known good" position.
1421             matroska->resync_pos = pos;
1422         }
1423 
1424         if (!data && length != EBML_UNKNOWN_LENGTH)
1425             goto skip;
1426     }
1427 
1428     switch (syntax->type) {
1429     case EBML_UINT:
1430         res = ebml_read_uint(pb, length, syntax->def.u, data);
1431         break;
1432     case EBML_SINT:
1433         res = ebml_read_sint(pb, length, syntax->def.i, data);
1434         break;
1435     case EBML_FLOAT:
1436         res = ebml_read_float(pb, length, syntax->def.f, data);
1437         break;
1438     case EBML_STR:
1439     case EBML_UTF8:
1440         res = ebml_read_ascii(pb, length, syntax->def.s, data);
1441         break;
1442     case EBML_BIN:
1443         res = ebml_read_binary(pb, length, pos_alt, data);
1444         break;
1445     case EBML_LEVEL1:
1446     case EBML_NEST:
1447         if ((res = ebml_read_master(matroska, length, pos_alt)) < 0)
1448             return res;
1449         if (id == MATROSKA_ID_SEGMENT)
1450             matroska->segment_start = pos_alt;
1451         if (id == MATROSKA_ID_CUES)
1452             matroska->cues_parsing_deferred = 0;
1453         if (syntax->type == EBML_LEVEL1 &&
1454             (level1_elem = matroska_find_level1_elem(matroska, syntax->id, pos))) {
1455             if (!level1_elem->pos) {
1456                 // Zero is not a valid position for a level 1 element.
1457                 level1_elem->pos = pos;
1458             } else if (level1_elem->pos != pos)
1459                 av_log(matroska->ctx, AV_LOG_ERROR, "Duplicate element\n");
1460             level1_elem->parsed = 1;
1461         }
1462         if (res = ebml_parse_nest(matroska, syntax->def.n, data))
1463             return res;
1464         break;
1465     case EBML_STOP:
1466         return 1;
1467     skip:
1468     default:
1469         if (length) {
1470             int64_t res2;
1471             if (ffio_limit(pb, length) != length) {
1472                 // ffio_limit emits its own error message,
1473                 // so we don't have to.
1474                 return AVERROR(EIO);
1475             }
1476             if ((res2 = avio_skip(pb, length - 1)) >= 0) {
1477                 // avio_skip might take us past EOF. We check for this
1478                 // by skipping only length - 1 bytes, reading a byte and
1479                 // checking the error flags. This is done in order to check
1480                 // that the element has been properly skipped even when
1481                 // no filesize (that ffio_limit relies on) is available.
1482                 avio_r8(pb);
1483                 res = NEEDS_CHECKING;
1484             } else
1485                 res = res2;
1486         } else
1487             res = 0;
1488     }
1489     if (res) {
1490         if (res == NEEDS_CHECKING) {
1491             if (pb->eof_reached) {
1492                 if (pb->error)
1493                     res = pb->error;
1494                 else
1495                     res = AVERROR_EOF;
1496             } else
1497                 goto level_check;
1498         }
1499 
1500         if (res == AVERROR_INVALIDDATA)
1501             av_log(matroska->ctx, AV_LOG_ERROR, "Invalid element\n");
1502         else if (res == AVERROR(EIO))
1503             av_log(matroska->ctx, AV_LOG_ERROR, "Read error\n");
1504         else if (res == AVERROR_EOF) {
1505             av_log(matroska->ctx, AV_LOG_ERROR, "File ended prematurely\n");
1506             res = AVERROR(EIO);
1507         }
1508 
1509         return res;
1510     }
1511 
1512 level_check:
1513     if (syntax->is_counted && data) {
1514         CountedElement *elem = data;
1515         if (elem->count != UINT_MAX)
1516             elem->count++;
1517     }
1518 
1519     if (level_check == LEVEL_ENDED && matroska->num_levels) {
1520         level = &matroska->levels[matroska->num_levels - 1];
1521         pos   = avio_tell(pb);
1522 
1523         // Given that pos >= level->start no check for
1524         // level->length != EBML_UNKNOWN_LENGTH is necessary.
1525         while (matroska->num_levels && pos == level->start + level->length) {
1526             matroska->num_levels--;
1527             level--;
1528         }
1529     }
1530 
1531     return level_check;
1532 }
1533 
ebml_free(EbmlSyntax * syntax,void * data)1534 static void ebml_free(EbmlSyntax *syntax, void *data)
1535 {
1536     int i, j;
1537     for (i = 0; syntax[i].id; i++) {
1538         void *data_off = (char *) data + syntax[i].data_offset;
1539         switch (syntax[i].type) {
1540         case EBML_STR:
1541         case EBML_UTF8:
1542             av_freep(data_off);
1543             break;
1544         case EBML_BIN:
1545             av_buffer_unref(&((EbmlBin *) data_off)->buf);
1546             break;
1547         case EBML_LEVEL1:
1548         case EBML_NEST:
1549             if (syntax[i].list_elem_size) {
1550                 EbmlList *list = data_off;
1551                 char *ptr = list->elem;
1552                 for (j = 0; j < list->nb_elem;
1553                      j++, ptr += syntax[i].list_elem_size)
1554                     ebml_free(syntax[i].def.n, ptr);
1555                 av_freep(&list->elem);
1556                 list->nb_elem = 0;
1557                 list->alloc_elem_size = 0;
1558             } else
1559                 ebml_free(syntax[i].def.n, data_off);
1560         default:
1561             break;
1562         }
1563     }
1564 }
1565 
1566 /*
1567  * Autodetecting...
1568  */
matroska_probe(const AVProbeData * p)1569 static int matroska_probe(const AVProbeData *p)
1570 {
1571     uint64_t total = 0;
1572     int len_mask = 0x80, size = 1, n = 1, i;
1573 
1574     /* EBML header? */
1575     if (AV_RB32(p->buf) != EBML_ID_HEADER)
1576         return 0;
1577 
1578     /* length of header */
1579     total = p->buf[4];
1580     while (size <= 8 && !(total & len_mask)) {
1581         size++;
1582         len_mask >>= 1;
1583     }
1584     if (size > 8)
1585         return 0;
1586     total &= (len_mask - 1);
1587     while (n < size)
1588         total = (total << 8) | p->buf[4 + n++];
1589 
1590     if (total + 1 == 1ULL << (7 * size)){
1591         /* Unknown-length header - simply parse the whole buffer. */
1592         total = p->buf_size - 4 - size;
1593     } else {
1594         /* Does the probe data contain the whole header? */
1595         if (p->buf_size < 4 + size + total)
1596             return 0;
1597     }
1598 
1599     /* The header should contain a known document type. For now,
1600      * we don't parse the whole header but simply check for the
1601      * availability of that array of characters inside the header.
1602      * Not fully fool-proof, but good enough. */
1603     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++) {
1604         size_t probelen = strlen(matroska_doctypes[i]);
1605         if (total < probelen)
1606             continue;
1607         for (n = 4 + size; n <= 4 + size + total - probelen; n++)
1608             if (!memcmp(p->buf + n, matroska_doctypes[i], probelen))
1609                 return AVPROBE_SCORE_MAX;
1610     }
1611 
1612     // probably valid EBML header but no recognized doctype
1613     return AVPROBE_SCORE_EXTENSION;
1614 }
1615 
matroska_find_track_by_num(MatroskaDemuxContext * matroska,uint64_t num)1616 static MatroskaTrack *matroska_find_track_by_num(MatroskaDemuxContext *matroska,
1617                                                  uint64_t num)
1618 {
1619     MatroskaTrack *tracks = matroska->tracks.elem;
1620     int i;
1621 
1622     for (i = 0; i < matroska->tracks.nb_elem; i++)
1623         if (tracks[i].num == num)
1624             return &tracks[i];
1625 
1626     av_log(matroska->ctx, AV_LOG_ERROR, "Invalid track number %"PRIu64"\n", num);
1627     return NULL;
1628 }
1629 
matroska_decode_buffer(uint8_t ** buf,int * buf_size,MatroskaTrack * track)1630 static int matroska_decode_buffer(uint8_t **buf, int *buf_size,
1631                                   MatroskaTrack *track)
1632 {
1633     MatroskaTrackEncoding *encodings = track->encodings.elem;
1634     uint8_t *data = *buf;
1635     int isize = *buf_size;
1636     uint8_t *pkt_data = NULL;
1637     uint8_t av_unused *newpktdata;
1638     int pkt_size = isize;
1639     int result = 0;
1640     int olen;
1641 
1642     if (pkt_size >= 10000000U)
1643         return AVERROR_INVALIDDATA;
1644 
1645     switch (encodings[0].compression.algo) {
1646     case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP:
1647     {
1648         int header_size = encodings[0].compression.settings.size;
1649         uint8_t *header = encodings[0].compression.settings.data;
1650 
1651         if (header_size && !header) {
1652             av_log(NULL, AV_LOG_ERROR, "Compression size but no data in headerstrip\n");
1653             return -1;
1654         }
1655 
1656         if (!header_size)
1657             return 0;
1658 
1659         pkt_size = isize + header_size;
1660         pkt_data = av_malloc(pkt_size + AV_INPUT_BUFFER_PADDING_SIZE);
1661         if (!pkt_data)
1662             return AVERROR(ENOMEM);
1663 
1664         memcpy(pkt_data, header, header_size);
1665         memcpy(pkt_data + header_size, data, isize);
1666         break;
1667     }
1668 #if CONFIG_LZO
1669     case MATROSKA_TRACK_ENCODING_COMP_LZO:
1670         do {
1671             int insize = isize;
1672             olen       = pkt_size *= 3;
1673             newpktdata = av_realloc(pkt_data, pkt_size + AV_LZO_OUTPUT_PADDING
1674                                                        + AV_INPUT_BUFFER_PADDING_SIZE);
1675             if (!newpktdata) {
1676                 result = AVERROR(ENOMEM);
1677                 goto failed;
1678             }
1679             pkt_data = newpktdata;
1680             result   = av_lzo1x_decode(pkt_data, &olen, data, &insize);
1681         } while (result == AV_LZO_OUTPUT_FULL && pkt_size < 10000000);
1682         if (result) {
1683             result = AVERROR_INVALIDDATA;
1684             goto failed;
1685         }
1686         pkt_size -= olen;
1687         break;
1688 #endif
1689 #if CONFIG_ZLIB
1690     case MATROSKA_TRACK_ENCODING_COMP_ZLIB:
1691     {
1692         z_stream zstream = { 0 };
1693         if (inflateInit(&zstream) != Z_OK)
1694             return -1;
1695         zstream.next_in  = data;
1696         zstream.avail_in = isize;
1697         do {
1698             pkt_size  *= 3;
1699             newpktdata = av_realloc(pkt_data, pkt_size + AV_INPUT_BUFFER_PADDING_SIZE);
1700             if (!newpktdata) {
1701                 inflateEnd(&zstream);
1702                 result = AVERROR(ENOMEM);
1703                 goto failed;
1704             }
1705             pkt_data          = newpktdata;
1706             zstream.avail_out = pkt_size - zstream.total_out;
1707             zstream.next_out  = pkt_data + zstream.total_out;
1708             result = inflate(&zstream, Z_NO_FLUSH);
1709         } while (result == Z_OK && pkt_size < 10000000);
1710         pkt_size = zstream.total_out;
1711         inflateEnd(&zstream);
1712         if (result != Z_STREAM_END) {
1713             if (result == Z_MEM_ERROR)
1714                 result = AVERROR(ENOMEM);
1715             else
1716                 result = AVERROR_INVALIDDATA;
1717             goto failed;
1718         }
1719         break;
1720     }
1721 #endif
1722 #if CONFIG_BZLIB
1723     case MATROSKA_TRACK_ENCODING_COMP_BZLIB:
1724     {
1725         bz_stream bzstream = { 0 };
1726         if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
1727             return -1;
1728         bzstream.next_in  = data;
1729         bzstream.avail_in = isize;
1730         do {
1731             pkt_size  *= 3;
1732             newpktdata = av_realloc(pkt_data, pkt_size + AV_INPUT_BUFFER_PADDING_SIZE);
1733             if (!newpktdata) {
1734                 BZ2_bzDecompressEnd(&bzstream);
1735                 result = AVERROR(ENOMEM);
1736                 goto failed;
1737             }
1738             pkt_data           = newpktdata;
1739             bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
1740             bzstream.next_out  = pkt_data + bzstream.total_out_lo32;
1741             result = BZ2_bzDecompress(&bzstream);
1742         } while (result == BZ_OK && pkt_size < 10000000);
1743         pkt_size = bzstream.total_out_lo32;
1744         BZ2_bzDecompressEnd(&bzstream);
1745         if (result != BZ_STREAM_END) {
1746             if (result == BZ_MEM_ERROR)
1747                 result = AVERROR(ENOMEM);
1748             else
1749                 result = AVERROR_INVALIDDATA;
1750             goto failed;
1751         }
1752         break;
1753     }
1754 #endif
1755     default:
1756         return AVERROR_INVALIDDATA;
1757     }
1758 
1759     memset(pkt_data + pkt_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
1760 
1761     *buf      = pkt_data;
1762     *buf_size = pkt_size;
1763     return 0;
1764 
1765 failed:
1766     av_free(pkt_data);
1767     return result;
1768 }
1769 
matroska_convert_tag(AVFormatContext * s,EbmlList * list,AVDictionary ** metadata,char * prefix)1770 static void matroska_convert_tag(AVFormatContext *s, EbmlList *list,
1771                                  AVDictionary **metadata, char *prefix)
1772 {
1773     MatroskaTag *tags = list->elem;
1774     char key[1024];
1775     int i;
1776 
1777     for (i = 0; i < list->nb_elem; i++) {
1778         const char *lang = tags[i].lang &&
1779                            strcmp(tags[i].lang, "und") ? tags[i].lang : NULL;
1780 
1781         if (!tags[i].name) {
1782             av_log(s, AV_LOG_WARNING, "Skipping invalid tag with no TagName.\n");
1783             continue;
1784         }
1785         if (prefix)
1786             snprintf(key, sizeof(key), "%s/%s", prefix, tags[i].name);
1787         else
1788             av_strlcpy(key, tags[i].name, sizeof(key));
1789         if (tags[i].def || !lang) {
1790             av_dict_set(metadata, key, tags[i].string, 0);
1791             if (tags[i].sub.nb_elem)
1792                 matroska_convert_tag(s, &tags[i].sub, metadata, key);
1793         }
1794         if (lang) {
1795             av_strlcat(key, "-", sizeof(key));
1796             av_strlcat(key, lang, sizeof(key));
1797             av_dict_set(metadata, key, tags[i].string, 0);
1798             if (tags[i].sub.nb_elem)
1799                 matroska_convert_tag(s, &tags[i].sub, metadata, key);
1800         }
1801     }
1802     ff_metadata_conv(metadata, NULL, ff_mkv_metadata_conv);
1803 }
1804 
matroska_convert_tags(AVFormatContext * s)1805 static void matroska_convert_tags(AVFormatContext *s)
1806 {
1807     MatroskaDemuxContext *matroska = s->priv_data;
1808     MatroskaTags *tags = matroska->tags.elem;
1809     int i, j;
1810 
1811     for (i = 0; i < matroska->tags.nb_elem; i++) {
1812         if (tags[i].target.attachuid) {
1813             MatroskaAttachment *attachment = matroska->attachments.elem;
1814             int found = 0;
1815             for (j = 0; j < matroska->attachments.nb_elem; j++) {
1816                 if (attachment[j].uid == tags[i].target.attachuid &&
1817                     attachment[j].stream) {
1818                     matroska_convert_tag(s, &tags[i].tag,
1819                                          &attachment[j].stream->metadata, NULL);
1820                     found = 1;
1821                 }
1822             }
1823             if (!found) {
1824                 av_log(s, AV_LOG_WARNING,
1825                        "The tags at index %d refer to a "
1826                        "non-existent attachment %"PRId64".\n",
1827                        i, tags[i].target.attachuid);
1828             }
1829         } else if (tags[i].target.chapteruid) {
1830             MatroskaChapter *chapter = matroska->chapters.elem;
1831             int found = 0;
1832             for (j = 0; j < matroska->chapters.nb_elem; j++) {
1833                 if (chapter[j].uid == tags[i].target.chapteruid &&
1834                     chapter[j].chapter) {
1835                     matroska_convert_tag(s, &tags[i].tag,
1836                                          &chapter[j].chapter->metadata, NULL);
1837                     found = 1;
1838                 }
1839             }
1840             if (!found) {
1841                 av_log(s, AV_LOG_WARNING,
1842                        "The tags at index %d refer to a non-existent chapter "
1843                        "%"PRId64".\n",
1844                        i, tags[i].target.chapteruid);
1845             }
1846         } else if (tags[i].target.trackuid) {
1847             MatroskaTrack *track = matroska->tracks.elem;
1848             int found = 0;
1849             for (j = 0; j < matroska->tracks.nb_elem; j++) {
1850                 if (track[j].uid == tags[i].target.trackuid &&
1851                     track[j].stream) {
1852                     matroska_convert_tag(s, &tags[i].tag,
1853                                          &track[j].stream->metadata, NULL);
1854                     found = 1;
1855                }
1856             }
1857             if (!found) {
1858                 av_log(s, AV_LOG_WARNING,
1859                        "The tags at index %d refer to a non-existent track "
1860                        "%"PRId64".\n",
1861                        i, tags[i].target.trackuid);
1862             }
1863         } else {
1864             matroska_convert_tag(s, &tags[i].tag, &s->metadata,
1865                                  tags[i].target.type);
1866         }
1867     }
1868 }
1869 
matroska_parse_seekhead_entry(MatroskaDemuxContext * matroska,int64_t pos)1870 static int matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska,
1871                                          int64_t pos)
1872 {
1873     uint32_t saved_id  = matroska->current_id;
1874     int64_t before_pos = avio_tell(matroska->ctx->pb);
1875     int ret = 0;
1876     int ret2;
1877 
1878     /* seek */
1879     if (avio_seek(matroska->ctx->pb, pos, SEEK_SET) == pos) {
1880         /* We don't want to lose our seekhead level, so we add
1881          * a dummy. This is a crude hack. */
1882         if (matroska->num_levels == EBML_MAX_DEPTH) {
1883             av_log(matroska->ctx, AV_LOG_INFO,
1884                    "Max EBML element depth (%d) reached, "
1885                    "cannot parse further.\n", EBML_MAX_DEPTH);
1886             ret = AVERROR_INVALIDDATA;
1887         } else {
1888             matroska->levels[matroska->num_levels] = (MatroskaLevel) { 0, EBML_UNKNOWN_LENGTH };
1889             matroska->num_levels++;
1890             matroska->current_id                   = 0;
1891 
1892             ret = ebml_parse(matroska, matroska_segment, matroska);
1893             if (ret == LEVEL_ENDED) {
1894                 /* This can only happen if the seek brought us beyond EOF. */
1895                 ret = AVERROR_EOF;
1896             }
1897         }
1898     }
1899     /* Seek back - notice that in all instances where this is used
1900      * it is safe to set the level to 1. */
1901     ret2 = matroska_reset_status(matroska, saved_id, before_pos);
1902     if (ret >= 0)
1903         ret = ret2;
1904 
1905     return ret;
1906 }
1907 
matroska_execute_seekhead(MatroskaDemuxContext * matroska)1908 static void matroska_execute_seekhead(MatroskaDemuxContext *matroska)
1909 {
1910     EbmlList *seekhead_list = &matroska->seekhead;
1911     int i;
1912 
1913     // we should not do any seeking in the streaming case
1914     if (!(matroska->ctx->pb->seekable & AVIO_SEEKABLE_NORMAL))
1915         return;
1916 
1917     for (i = 0; i < seekhead_list->nb_elem; i++) {
1918         MatroskaSeekhead *seekheads = seekhead_list->elem;
1919         uint32_t id = seekheads[i].id;
1920         int64_t pos = seekheads[i].pos + matroska->segment_start;
1921         MatroskaLevel1Element *elem;
1922 
1923         if (id != seekheads[i].id || pos < matroska->segment_start)
1924             continue;
1925 
1926         elem = matroska_find_level1_elem(matroska, id, pos);
1927         if (!elem || elem->parsed)
1928             continue;
1929 
1930         elem->pos = pos;
1931 
1932         // defer cues parsing until we actually need cue data.
1933         if (id == MATROSKA_ID_CUES)
1934             continue;
1935 
1936         if (matroska_parse_seekhead_entry(matroska, pos) < 0) {
1937             // mark index as broken
1938             matroska->cues_parsing_deferred = -1;
1939             break;
1940         }
1941 
1942         elem->parsed = 1;
1943     }
1944 }
1945 
matroska_add_index_entries(MatroskaDemuxContext * matroska)1946 static void matroska_add_index_entries(MatroskaDemuxContext *matroska)
1947 {
1948     EbmlList *index_list;
1949     MatroskaIndex *index;
1950     uint64_t index_scale = 1;
1951     int i, j;
1952 
1953     if (matroska->ctx->flags & AVFMT_FLAG_IGNIDX)
1954         return;
1955 
1956     index_list = &matroska->index;
1957     index      = index_list->elem;
1958     if (index_list->nb_elem < 2)
1959         return;
1960     if (index[1].time > 1E14 / matroska->time_scale) {
1961         av_log(matroska->ctx, AV_LOG_WARNING, "Dropping apparently-broken index.\n");
1962         return;
1963     }
1964     for (i = 0; i < index_list->nb_elem; i++) {
1965         EbmlList *pos_list    = &index[i].pos;
1966         MatroskaIndexPos *pos = pos_list->elem;
1967         for (j = 0; j < pos_list->nb_elem; j++) {
1968             MatroskaTrack *track = matroska_find_track_by_num(matroska,
1969                                                               pos[j].track);
1970             if (track && track->stream)
1971                 av_add_index_entry(track->stream,
1972                                    pos[j].pos + matroska->segment_start,
1973                                    index[i].time / index_scale, 0, 0,
1974                                    AVINDEX_KEYFRAME);
1975         }
1976     }
1977 }
1978 
matroska_parse_cues(MatroskaDemuxContext * matroska)1979 static void matroska_parse_cues(MatroskaDemuxContext *matroska) {
1980     int i;
1981 
1982     if (matroska->ctx->flags & AVFMT_FLAG_IGNIDX)
1983         return;
1984 
1985     for (i = 0; i < matroska->num_level1_elems; i++) {
1986         MatroskaLevel1Element *elem = &matroska->level1_elems[i];
1987         if (elem->id == MATROSKA_ID_CUES && !elem->parsed) {
1988             if (matroska_parse_seekhead_entry(matroska, elem->pos) < 0)
1989                 matroska->cues_parsing_deferred = -1;
1990             elem->parsed = 1;
1991             break;
1992         }
1993     }
1994 
1995     matroska_add_index_entries(matroska);
1996 }
1997 
matroska_aac_profile(char * codec_id)1998 static int matroska_aac_profile(char *codec_id)
1999 {
2000     static const char *const aac_profiles[] = { "MAIN", "LC", "SSR" };
2001     int profile;
2002 
2003     for (profile = 0; profile < FF_ARRAY_ELEMS(aac_profiles); profile++)
2004         if (strstr(codec_id, aac_profiles[profile]))
2005             break;
2006     return profile + 1;
2007 }
2008 
matroska_aac_sri(int samplerate)2009 static int matroska_aac_sri(int samplerate)
2010 {
2011     int sri;
2012 
2013     for (sri = 0; sri < FF_ARRAY_ELEMS(avpriv_mpeg4audio_sample_rates); sri++)
2014         if (avpriv_mpeg4audio_sample_rates[sri] == samplerate)
2015             break;
2016     return sri;
2017 }
2018 
matroska_metadata_creation_time(AVDictionary ** metadata,int64_t date_utc)2019 static void matroska_metadata_creation_time(AVDictionary **metadata, int64_t date_utc)
2020 {
2021     /* Convert to seconds and adjust by number of seconds between 2001-01-01 and Epoch */
2022     avpriv_dict_set_timestamp(metadata, "creation_time", date_utc / 1000 + 978307200000000LL);
2023 }
2024 
matroska_parse_flac(AVFormatContext * s,MatroskaTrack * track,int * offset)2025 static int matroska_parse_flac(AVFormatContext *s,
2026                                MatroskaTrack *track,
2027                                int *offset)
2028 {
2029     AVStream *st = track->stream;
2030     uint8_t *p = track->codec_priv.data;
2031     int size   = track->codec_priv.size;
2032 
2033     if (size < 8 + FLAC_STREAMINFO_SIZE || p[4] & 0x7f) {
2034         av_log(s, AV_LOG_WARNING, "Invalid FLAC private data\n");
2035         track->codec_priv.size = 0;
2036         return 0;
2037     }
2038     *offset = 8;
2039     track->codec_priv.size = 8 + FLAC_STREAMINFO_SIZE;
2040 
2041     p    += track->codec_priv.size;
2042     size -= track->codec_priv.size;
2043 
2044     /* parse the remaining metadata blocks if present */
2045     while (size >= 4) {
2046         int block_last, block_type, block_size;
2047 
2048         flac_parse_block_header(p, &block_last, &block_type, &block_size);
2049 
2050         p    += 4;
2051         size -= 4;
2052         if (block_size > size)
2053             return 0;
2054 
2055         /* check for the channel mask */
2056         if (block_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
2057             AVDictionary *dict = NULL;
2058             AVDictionaryEntry *chmask;
2059 
2060             ff_vorbis_comment(s, &dict, p, block_size, 0);
2061             chmask = av_dict_get(dict, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
2062             if (chmask) {
2063                 uint64_t mask = strtol(chmask->value, NULL, 0);
2064                 if (!mask || mask & ~0x3ffffULL) {
2065                     av_log(s, AV_LOG_WARNING,
2066                            "Invalid value of WAVEFORMATEXTENSIBLE_CHANNEL_MASK\n");
2067                 } else
2068                     st->codecpar->channel_layout = mask;
2069             }
2070             av_dict_free(&dict);
2071         }
2072 
2073         p    += block_size;
2074         size -= block_size;
2075     }
2076 
2077     return 0;
2078 }
2079 
mkv_field_order(MatroskaDemuxContext * matroska,int64_t field_order)2080 static int mkv_field_order(MatroskaDemuxContext *matroska, int64_t field_order)
2081 {
2082     int minor, micro, bttb = 0;
2083 
2084     /* workaround a bug in our Matroska muxer, introduced in version 57.36 alongside
2085      * this function, and fixed in 57.52 */
2086     if (matroska->muxingapp && sscanf(matroska->muxingapp, "Lavf57.%d.%d", &minor, &micro) == 2)
2087         bttb = (minor >= 36 && minor <= 51 && micro >= 100);
2088 
2089     switch (field_order) {
2090     case MATROSKA_VIDEO_FIELDORDER_PROGRESSIVE:
2091         return AV_FIELD_PROGRESSIVE;
2092     case MATROSKA_VIDEO_FIELDORDER_UNDETERMINED:
2093         return AV_FIELD_UNKNOWN;
2094     case MATROSKA_VIDEO_FIELDORDER_TT:
2095         return AV_FIELD_TT;
2096     case MATROSKA_VIDEO_FIELDORDER_BB:
2097         return AV_FIELD_BB;
2098     case MATROSKA_VIDEO_FIELDORDER_BT:
2099         return bttb ? AV_FIELD_TB : AV_FIELD_BT;
2100     case MATROSKA_VIDEO_FIELDORDER_TB:
2101         return bttb ? AV_FIELD_BT : AV_FIELD_TB;
2102     default:
2103         return AV_FIELD_UNKNOWN;
2104     }
2105 }
2106 
mkv_stereo_mode_display_mul(int stereo_mode,int * h_width,int * h_height)2107 static void mkv_stereo_mode_display_mul(int stereo_mode,
2108                                         int *h_width, int *h_height)
2109 {
2110     switch (stereo_mode) {
2111         case MATROSKA_VIDEO_STEREOMODE_TYPE_MONO:
2112         case MATROSKA_VIDEO_STEREOMODE_TYPE_CHECKERBOARD_RL:
2113         case MATROSKA_VIDEO_STEREOMODE_TYPE_CHECKERBOARD_LR:
2114         case MATROSKA_VIDEO_STEREOMODE_TYPE_BOTH_EYES_BLOCK_RL:
2115         case MATROSKA_VIDEO_STEREOMODE_TYPE_BOTH_EYES_BLOCK_LR:
2116             break;
2117         case MATROSKA_VIDEO_STEREOMODE_TYPE_RIGHT_LEFT:
2118         case MATROSKA_VIDEO_STEREOMODE_TYPE_LEFT_RIGHT:
2119         case MATROSKA_VIDEO_STEREOMODE_TYPE_COL_INTERLEAVED_RL:
2120         case MATROSKA_VIDEO_STEREOMODE_TYPE_COL_INTERLEAVED_LR:
2121             *h_width = 2;
2122             break;
2123         case MATROSKA_VIDEO_STEREOMODE_TYPE_BOTTOM_TOP:
2124         case MATROSKA_VIDEO_STEREOMODE_TYPE_TOP_BOTTOM:
2125         case MATROSKA_VIDEO_STEREOMODE_TYPE_ROW_INTERLEAVED_RL:
2126         case MATROSKA_VIDEO_STEREOMODE_TYPE_ROW_INTERLEAVED_LR:
2127             *h_height = 2;
2128             break;
2129     }
2130 }
2131 
mkv_parse_video_color(AVStream * st,const MatroskaTrack * track)2132 static int mkv_parse_video_color(AVStream *st, const MatroskaTrack *track) {
2133     const MatroskaTrackVideoColor *color = track->video.color.elem;
2134     const MatroskaMasteringMeta *mastering_meta;
2135     int has_mastering_primaries, has_mastering_luminance;
2136 
2137     if (!track->video.color.nb_elem)
2138         return 0;
2139 
2140     mastering_meta = &color->mastering_meta;
2141     // Mastering primaries are CIE 1931 coords, and must be > 0.
2142     has_mastering_primaries =
2143         mastering_meta->r_x > 0 && mastering_meta->r_y > 0 &&
2144         mastering_meta->g_x > 0 && mastering_meta->g_y > 0 &&
2145         mastering_meta->b_x > 0 && mastering_meta->b_y > 0 &&
2146         mastering_meta->white_x > 0 && mastering_meta->white_y > 0;
2147     has_mastering_luminance = mastering_meta->max_luminance >
2148                                   mastering_meta->min_luminance.el.f  &&
2149                               mastering_meta->min_luminance.el.f >= 0 &&
2150                               mastering_meta->min_luminance.count;
2151 
2152     if (color->matrix_coefficients != AVCOL_SPC_RESERVED)
2153         st->codecpar->color_space = color->matrix_coefficients;
2154     if (color->primaries != AVCOL_PRI_RESERVED &&
2155         color->primaries != AVCOL_PRI_RESERVED0)
2156         st->codecpar->color_primaries = color->primaries;
2157     if (color->transfer_characteristics != AVCOL_TRC_RESERVED &&
2158         color->transfer_characteristics != AVCOL_TRC_RESERVED0)
2159         st->codecpar->color_trc = color->transfer_characteristics;
2160     if (color->range != AVCOL_RANGE_UNSPECIFIED &&
2161         color->range <= AVCOL_RANGE_JPEG)
2162         st->codecpar->color_range = color->range;
2163     if (color->chroma_siting_horz != MATROSKA_COLOUR_CHROMASITINGHORZ_UNDETERMINED &&
2164         color->chroma_siting_vert != MATROSKA_COLOUR_CHROMASITINGVERT_UNDETERMINED &&
2165         color->chroma_siting_horz  < MATROSKA_COLOUR_CHROMASITINGHORZ_NB &&
2166         color->chroma_siting_vert  < MATROSKA_COLOUR_CHROMASITINGVERT_NB) {
2167         st->codecpar->chroma_location =
2168             avcodec_chroma_pos_to_enum((color->chroma_siting_horz - 1) << 7,
2169                                        (color->chroma_siting_vert - 1) << 7);
2170     }
2171     if (color->max_cll && color->max_fall) {
2172         size_t size = 0;
2173         int ret;
2174         AVContentLightMetadata *metadata = av_content_light_metadata_alloc(&size);
2175         if (!metadata)
2176             return AVERROR(ENOMEM);
2177         ret = av_stream_add_side_data(st, AV_PKT_DATA_CONTENT_LIGHT_LEVEL,
2178                                       (uint8_t *)metadata, size);
2179         if (ret < 0) {
2180             av_freep(&metadata);
2181             return ret;
2182         }
2183         metadata->MaxCLL  = color->max_cll;
2184         metadata->MaxFALL = color->max_fall;
2185     }
2186 
2187     if (has_mastering_primaries || has_mastering_luminance) {
2188         AVMasteringDisplayMetadata *metadata =
2189             (AVMasteringDisplayMetadata*) av_stream_new_side_data(
2190                 st, AV_PKT_DATA_MASTERING_DISPLAY_METADATA,
2191                 sizeof(AVMasteringDisplayMetadata));
2192         if (!metadata) {
2193             return AVERROR(ENOMEM);
2194         }
2195         memset(metadata, 0, sizeof(AVMasteringDisplayMetadata));
2196         if (has_mastering_primaries) {
2197             metadata->display_primaries[0][0] = av_d2q(mastering_meta->r_x, INT_MAX);
2198             metadata->display_primaries[0][1] = av_d2q(mastering_meta->r_y, INT_MAX);
2199             metadata->display_primaries[1][0] = av_d2q(mastering_meta->g_x, INT_MAX);
2200             metadata->display_primaries[1][1] = av_d2q(mastering_meta->g_y, INT_MAX);
2201             metadata->display_primaries[2][0] = av_d2q(mastering_meta->b_x, INT_MAX);
2202             metadata->display_primaries[2][1] = av_d2q(mastering_meta->b_y, INT_MAX);
2203             metadata->white_point[0] = av_d2q(mastering_meta->white_x, INT_MAX);
2204             metadata->white_point[1] = av_d2q(mastering_meta->white_y, INT_MAX);
2205             metadata->has_primaries = 1;
2206         }
2207         if (has_mastering_luminance) {
2208             metadata->max_luminance = av_d2q(mastering_meta->max_luminance, INT_MAX);
2209             metadata->min_luminance = av_d2q(mastering_meta->min_luminance.el.f, INT_MAX);
2210             metadata->has_luminance = 1;
2211         }
2212     }
2213     return 0;
2214 }
2215 
mkv_parse_video_projection(AVStream * st,const MatroskaTrack * track,void * logctx)2216 static int mkv_parse_video_projection(AVStream *st, const MatroskaTrack *track,
2217                                       void *logctx)
2218 {
2219     AVSphericalMapping *spherical;
2220     const MatroskaTrackVideoProjection *mkv_projection = &track->video.projection;
2221     const uint8_t *priv_data = mkv_projection->private.data;
2222     enum AVSphericalProjection projection;
2223     size_t spherical_size;
2224     uint32_t l = 0, t = 0, r = 0, b = 0;
2225     uint32_t padding = 0;
2226     int ret;
2227 
2228     if (mkv_projection->private.size && priv_data[0] != 0) {
2229         av_log(logctx, AV_LOG_WARNING, "Unknown spherical metadata\n");
2230         return 0;
2231     }
2232 
2233     switch (track->video.projection.type) {
2234     case MATROSKA_VIDEO_PROJECTION_TYPE_EQUIRECTANGULAR:
2235         if (track->video.projection.private.size == 20) {
2236             t = AV_RB32(priv_data +  4);
2237             b = AV_RB32(priv_data +  8);
2238             l = AV_RB32(priv_data + 12);
2239             r = AV_RB32(priv_data + 16);
2240 
2241             if (b >= UINT_MAX - t || r >= UINT_MAX - l) {
2242                 av_log(logctx, AV_LOG_ERROR,
2243                        "Invalid bounding rectangle coordinates "
2244                        "%"PRIu32",%"PRIu32",%"PRIu32",%"PRIu32"\n",
2245                        l, t, r, b);
2246                 return AVERROR_INVALIDDATA;
2247             }
2248         } else if (track->video.projection.private.size != 0) {
2249             av_log(logctx, AV_LOG_ERROR, "Unknown spherical metadata\n");
2250             return AVERROR_INVALIDDATA;
2251         }
2252 
2253         if (l || t || r || b)
2254             projection = AV_SPHERICAL_EQUIRECTANGULAR_TILE;
2255         else
2256             projection = AV_SPHERICAL_EQUIRECTANGULAR;
2257         break;
2258     case MATROSKA_VIDEO_PROJECTION_TYPE_CUBEMAP:
2259         if (track->video.projection.private.size < 4) {
2260             av_log(logctx, AV_LOG_ERROR, "Missing projection private properties\n");
2261             return AVERROR_INVALIDDATA;
2262         } else if (track->video.projection.private.size == 12) {
2263             uint32_t layout = AV_RB32(priv_data + 4);
2264             if (layout) {
2265                 av_log(logctx, AV_LOG_WARNING,
2266                        "Unknown spherical cubemap layout %"PRIu32"\n", layout);
2267                 return 0;
2268             }
2269             projection = AV_SPHERICAL_CUBEMAP;
2270             padding = AV_RB32(priv_data + 8);
2271         } else {
2272             av_log(logctx, AV_LOG_ERROR, "Unknown spherical metadata\n");
2273             return AVERROR_INVALIDDATA;
2274         }
2275         break;
2276     case MATROSKA_VIDEO_PROJECTION_TYPE_RECTANGULAR:
2277         /* No Spherical metadata */
2278         return 0;
2279     default:
2280         av_log(logctx, AV_LOG_WARNING,
2281                "Unknown spherical metadata type %"PRIu64"\n",
2282                track->video.projection.type);
2283         return 0;
2284     }
2285 
2286     spherical = av_spherical_alloc(&spherical_size);
2287     if (!spherical)
2288         return AVERROR(ENOMEM);
2289 
2290     spherical->projection = projection;
2291 
2292     spherical->yaw   = (int32_t) (track->video.projection.yaw   * (1 << 16));
2293     spherical->pitch = (int32_t) (track->video.projection.pitch * (1 << 16));
2294     spherical->roll  = (int32_t) (track->video.projection.roll  * (1 << 16));
2295 
2296     spherical->padding = padding;
2297 
2298     spherical->bound_left   = l;
2299     spherical->bound_top    = t;
2300     spherical->bound_right  = r;
2301     spherical->bound_bottom = b;
2302 
2303     ret = av_stream_add_side_data(st, AV_PKT_DATA_SPHERICAL, (uint8_t *)spherical,
2304                                   spherical_size);
2305     if (ret < 0) {
2306         av_freep(&spherical);
2307         return ret;
2308     }
2309 
2310     return 0;
2311 }
2312 
get_qt_codec(MatroskaTrack * track,uint32_t * fourcc,enum AVCodecID * codec_id)2313 static int get_qt_codec(MatroskaTrack *track, uint32_t *fourcc, enum AVCodecID *codec_id)
2314 {
2315     const AVCodecTag *codec_tags;
2316 
2317     codec_tags = track->type == MATROSKA_TRACK_TYPE_VIDEO ?
2318             ff_codec_movvideo_tags : ff_codec_movaudio_tags;
2319 
2320     /* Normalize noncompliant private data that starts with the fourcc
2321      * by expanding/shifting the data by 4 bytes and storing the data
2322      * size at the start. */
2323     if (ff_codec_get_id(codec_tags, AV_RL32(track->codec_priv.data))) {
2324         int ret = av_buffer_realloc(&track->codec_priv.buf,
2325                                     track->codec_priv.size + 4 + AV_INPUT_BUFFER_PADDING_SIZE);
2326         if (ret < 0)
2327             return ret;
2328 
2329         track->codec_priv.data = track->codec_priv.buf->data;
2330         memmove(track->codec_priv.data + 4, track->codec_priv.data, track->codec_priv.size);
2331         track->codec_priv.size += 4;
2332         AV_WB32(track->codec_priv.data, track->codec_priv.size);
2333     }
2334 
2335     *fourcc = AV_RL32(track->codec_priv.data + 4);
2336     *codec_id = ff_codec_get_id(codec_tags, *fourcc);
2337 
2338     return 0;
2339 }
2340 
matroska_parse_tracks(AVFormatContext * s)2341 static int matroska_parse_tracks(AVFormatContext *s)
2342 {
2343     MatroskaDemuxContext *matroska = s->priv_data;
2344     MatroskaTrack *tracks = matroska->tracks.elem;
2345     AVStream *st;
2346     int i, j, ret;
2347     int k;
2348 
2349     for (i = 0; i < matroska->tracks.nb_elem; i++) {
2350         MatroskaTrack *track = &tracks[i];
2351         enum AVCodecID codec_id = AV_CODEC_ID_NONE;
2352         EbmlList *encodings_list = &track->encodings;
2353         MatroskaTrackEncoding *encodings = encodings_list->elem;
2354         uint8_t *extradata = NULL;
2355         int extradata_size = 0;
2356         int extradata_offset = 0;
2357         uint32_t fourcc = 0;
2358         AVIOContext b;
2359         char* key_id_base64 = NULL;
2360         int bit_depth = -1;
2361 
2362         /* Apply some sanity checks. */
2363         if (track->type != MATROSKA_TRACK_TYPE_VIDEO &&
2364             track->type != MATROSKA_TRACK_TYPE_AUDIO &&
2365             track->type != MATROSKA_TRACK_TYPE_SUBTITLE &&
2366             track->type != MATROSKA_TRACK_TYPE_METADATA) {
2367             av_log(matroska->ctx, AV_LOG_INFO,
2368                    "Unknown or unsupported track type %"PRIu64"\n",
2369                    track->type);
2370             continue;
2371         }
2372         if (!track->codec_id)
2373             continue;
2374 
2375         if (   track->type == MATROSKA_TRACK_TYPE_AUDIO && track->codec_id[0] != 'A'
2376             || track->type == MATROSKA_TRACK_TYPE_VIDEO && track->codec_id[0] != 'V'
2377             || track->type == MATROSKA_TRACK_TYPE_SUBTITLE && track->codec_id[0] != 'D' && track->codec_id[0] != 'S'
2378             || track->type == MATROSKA_TRACK_TYPE_METADATA && track->codec_id[0] != 'D' && track->codec_id[0] != 'S'
2379         ) {
2380             av_log(matroska->ctx, AV_LOG_INFO, "Inconsistent track type\n");
2381             continue;
2382         }
2383 
2384         if (track->audio.samplerate < 0 || track->audio.samplerate > INT_MAX ||
2385             isnan(track->audio.samplerate)) {
2386             av_log(matroska->ctx, AV_LOG_WARNING,
2387                    "Invalid sample rate %f, defaulting to 8000 instead.\n",
2388                    track->audio.samplerate);
2389             track->audio.samplerate = 8000;
2390         }
2391 
2392         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
2393             if (!track->default_duration && track->video.frame_rate > 0) {
2394                 double default_duration = 1000000000 / track->video.frame_rate;
2395                 if (default_duration > UINT64_MAX || default_duration < 0) {
2396                     av_log(matroska->ctx, AV_LOG_WARNING,
2397                          "Invalid frame rate %e. Cannot calculate default duration.\n",
2398                          track->video.frame_rate);
2399                 } else {
2400                     track->default_duration = default_duration;
2401                 }
2402             }
2403             if (track->video.display_width == -1)
2404                 track->video.display_width = track->video.pixel_width;
2405             if (track->video.display_height == -1)
2406                 track->video.display_height = track->video.pixel_height;
2407             if (track->video.color_space.size == 4)
2408                 fourcc = AV_RL32(track->video.color_space.data);
2409         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
2410             if (!track->audio.out_samplerate)
2411                 track->audio.out_samplerate = track->audio.samplerate;
2412         }
2413         if (encodings_list->nb_elem > 1) {
2414             av_log(matroska->ctx, AV_LOG_ERROR,
2415                    "Multiple combined encodings not supported");
2416         } else if (encodings_list->nb_elem == 1) {
2417             if (encodings[0].type) {
2418                 if (encodings[0].encryption.key_id.size > 0) {
2419                     /* Save the encryption key id to be stored later as a
2420                        metadata tag. */
2421                     const int b64_size = AV_BASE64_SIZE(encodings[0].encryption.key_id.size);
2422                     key_id_base64 = av_malloc(b64_size);
2423                     if (key_id_base64 == NULL)
2424                         return AVERROR(ENOMEM);
2425 
2426                     av_base64_encode(key_id_base64, b64_size,
2427                                      encodings[0].encryption.key_id.data,
2428                                      encodings[0].encryption.key_id.size);
2429                 } else {
2430                     encodings[0].scope = 0;
2431                     av_log(matroska->ctx, AV_LOG_ERROR,
2432                            "Unsupported encoding type");
2433                 }
2434             } else if (
2435 #if CONFIG_ZLIB
2436                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_ZLIB  &&
2437 #endif
2438 #if CONFIG_BZLIB
2439                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_BZLIB &&
2440 #endif
2441 #if CONFIG_LZO
2442                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_LZO   &&
2443 #endif
2444                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP) {
2445                 encodings[0].scope = 0;
2446                 av_log(matroska->ctx, AV_LOG_ERROR,
2447                        "Unsupported encoding type");
2448             } else if (track->codec_priv.size && encodings[0].scope & 2) {
2449                 uint8_t *codec_priv = track->codec_priv.data;
2450                 int ret = matroska_decode_buffer(&track->codec_priv.data,
2451                                                  &track->codec_priv.size,
2452                                                  track);
2453                 if (ret < 0) {
2454                     track->codec_priv.data = NULL;
2455                     track->codec_priv.size = 0;
2456                     av_log(matroska->ctx, AV_LOG_ERROR,
2457                            "Failed to decode codec private data\n");
2458                 }
2459 
2460                 if (codec_priv != track->codec_priv.data) {
2461                     av_buffer_unref(&track->codec_priv.buf);
2462                     if (track->codec_priv.data) {
2463                         track->codec_priv.buf = av_buffer_create(track->codec_priv.data,
2464                                                                  track->codec_priv.size + AV_INPUT_BUFFER_PADDING_SIZE,
2465                                                                  NULL, NULL, 0);
2466                         if (!track->codec_priv.buf) {
2467                             av_freep(&track->codec_priv.data);
2468                             track->codec_priv.size = 0;
2469                             return AVERROR(ENOMEM);
2470                         }
2471                     }
2472                 }
2473             }
2474         }
2475         track->needs_decoding = encodings && !encodings[0].type &&
2476                                 encodings[0].scope & 1          &&
2477                                 (encodings[0].compression.algo !=
2478                                    MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP ||
2479                                  encodings[0].compression.settings.size);
2480 
2481         for (j = 0; ff_mkv_codec_tags[j].id != AV_CODEC_ID_NONE; j++) {
2482             if (av_strstart(track->codec_id, ff_mkv_codec_tags[j].str, NULL)) {
2483                 codec_id = ff_mkv_codec_tags[j].id;
2484                 break;
2485             }
2486         }
2487 
2488         st = track->stream = avformat_new_stream(s, NULL);
2489         if (!st) {
2490             av_free(key_id_base64);
2491             return AVERROR(ENOMEM);
2492         }
2493 
2494         if (key_id_base64) {
2495             /* export encryption key id as base64 metadata tag */
2496             av_dict_set(&st->metadata, "enc_key_id", key_id_base64,
2497                         AV_DICT_DONT_STRDUP_VAL);
2498         }
2499 
2500         if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC") &&
2501              track->codec_priv.size >= 40               &&
2502             track->codec_priv.data) {
2503             track->ms_compat    = 1;
2504             bit_depth           = AV_RL16(track->codec_priv.data + 14);
2505             fourcc              = AV_RL32(track->codec_priv.data + 16);
2506             codec_id            = ff_codec_get_id(ff_codec_bmp_tags,
2507                                                   fourcc);
2508             if (!codec_id)
2509                 codec_id        = ff_codec_get_id(ff_codec_movvideo_tags,
2510                                                   fourcc);
2511             extradata_offset    = 40;
2512         } else if (!strcmp(track->codec_id, "A_MS/ACM") &&
2513                    track->codec_priv.size >= 14         &&
2514                    track->codec_priv.data) {
2515             int ret;
2516             ffio_init_context(&b, track->codec_priv.data,
2517                               track->codec_priv.size,
2518                               0, NULL, NULL, NULL, NULL);
2519             ret = ff_get_wav_header(s, &b, st->codecpar, track->codec_priv.size, 0);
2520             if (ret < 0)
2521                 return ret;
2522             codec_id         = st->codecpar->codec_id;
2523             fourcc           = st->codecpar->codec_tag;
2524             extradata_offset = FFMIN(track->codec_priv.size, 18);
2525         } else if (!strcmp(track->codec_id, "A_QUICKTIME")
2526                    /* Normally 36, but allow noncompliant private data */
2527                    && (track->codec_priv.size >= 32)
2528                    && (track->codec_priv.data)) {
2529             uint16_t sample_size;
2530             int ret = get_qt_codec(track, &fourcc, &codec_id);
2531             if (ret < 0)
2532                 return ret;
2533             sample_size = AV_RB16(track->codec_priv.data + 26);
2534             if (fourcc == 0) {
2535                 if (sample_size == 8) {
2536                     fourcc = MKTAG('r','a','w',' ');
2537                     codec_id = ff_codec_get_id(ff_codec_movaudio_tags, fourcc);
2538                 } else if (sample_size == 16) {
2539                     fourcc = MKTAG('t','w','o','s');
2540                     codec_id = ff_codec_get_id(ff_codec_movaudio_tags, fourcc);
2541                 }
2542             }
2543             if ((fourcc == MKTAG('t','w','o','s') ||
2544                     fourcc == MKTAG('s','o','w','t')) &&
2545                     sample_size == 8)
2546                 codec_id = AV_CODEC_ID_PCM_S8;
2547         } else if (!strcmp(track->codec_id, "V_QUICKTIME") &&
2548                    (track->codec_priv.size >= 21)          &&
2549                    (track->codec_priv.data)) {
2550             int ret = get_qt_codec(track, &fourcc, &codec_id);
2551             if (ret < 0)
2552                 return ret;
2553             if (codec_id == AV_CODEC_ID_NONE && AV_RL32(track->codec_priv.data+4) == AV_RL32("SMI ")) {
2554                 fourcc = MKTAG('S','V','Q','3');
2555                 codec_id = ff_codec_get_id(ff_codec_movvideo_tags, fourcc);
2556             }
2557             if (codec_id == AV_CODEC_ID_NONE)
2558                 av_log(matroska->ctx, AV_LOG_ERROR,
2559                        "mov FourCC not found %s.\n", av_fourcc2str(fourcc));
2560             if (track->codec_priv.size >= 86) {
2561                 bit_depth = AV_RB16(track->codec_priv.data + 82);
2562                 ffio_init_context(&b, track->codec_priv.data,
2563                                   track->codec_priv.size,
2564                                   0, NULL, NULL, NULL, NULL);
2565                 if (ff_get_qtpalette(codec_id, &b, track->palette)) {
2566                     bit_depth &= 0x1F;
2567                     track->has_palette = 1;
2568                 }
2569             }
2570         } else if (codec_id == AV_CODEC_ID_PCM_S16BE) {
2571             switch (track->audio.bitdepth) {
2572             case  8:
2573                 codec_id = AV_CODEC_ID_PCM_U8;
2574                 break;
2575             case 24:
2576                 codec_id = AV_CODEC_ID_PCM_S24BE;
2577                 break;
2578             case 32:
2579                 codec_id = AV_CODEC_ID_PCM_S32BE;
2580                 break;
2581             }
2582         } else if (codec_id == AV_CODEC_ID_PCM_S16LE) {
2583             switch (track->audio.bitdepth) {
2584             case  8:
2585                 codec_id = AV_CODEC_ID_PCM_U8;
2586                 break;
2587             case 24:
2588                 codec_id = AV_CODEC_ID_PCM_S24LE;
2589                 break;
2590             case 32:
2591                 codec_id = AV_CODEC_ID_PCM_S32LE;
2592                 break;
2593             }
2594         } else if (codec_id == AV_CODEC_ID_PCM_F32LE &&
2595                    track->audio.bitdepth == 64) {
2596             codec_id = AV_CODEC_ID_PCM_F64LE;
2597         } else if (codec_id == AV_CODEC_ID_AAC && !track->codec_priv.size) {
2598             int profile = matroska_aac_profile(track->codec_id);
2599             int sri     = matroska_aac_sri(track->audio.samplerate);
2600             extradata   = av_mallocz(5 + AV_INPUT_BUFFER_PADDING_SIZE);
2601             if (!extradata)
2602                 return AVERROR(ENOMEM);
2603             extradata[0] = (profile << 3) | ((sri & 0x0E) >> 1);
2604             extradata[1] = ((sri & 0x01) << 7) | (track->audio.channels << 3);
2605             if (strstr(track->codec_id, "SBR")) {
2606                 sri            = matroska_aac_sri(track->audio.out_samplerate);
2607                 extradata[2]   = 0x56;
2608                 extradata[3]   = 0xE5;
2609                 extradata[4]   = 0x80 | (sri << 3);
2610                 extradata_size = 5;
2611             } else
2612                 extradata_size = 2;
2613         } else if (codec_id == AV_CODEC_ID_ALAC && track->codec_priv.size && track->codec_priv.size < INT_MAX - 12 - AV_INPUT_BUFFER_PADDING_SIZE) {
2614             /* Only ALAC's magic cookie is stored in Matroska's track headers.
2615              * Create the "atom size", "tag", and "tag version" fields the
2616              * decoder expects manually. */
2617             extradata_size = 12 + track->codec_priv.size;
2618             extradata      = av_mallocz(extradata_size +
2619                                         AV_INPUT_BUFFER_PADDING_SIZE);
2620             if (!extradata)
2621                 return AVERROR(ENOMEM);
2622             AV_WB32(extradata, extradata_size);
2623             memcpy(&extradata[4], "alac", 4);
2624             AV_WB32(&extradata[8], 0);
2625             memcpy(&extradata[12], track->codec_priv.data,
2626                    track->codec_priv.size);
2627         } else if (codec_id == AV_CODEC_ID_TTA) {
2628             uint8_t *ptr;
2629             if (track->audio.channels > UINT16_MAX ||
2630                 track->audio.bitdepth > UINT16_MAX) {
2631                 av_log(matroska->ctx, AV_LOG_WARNING,
2632                        "Too large audio channel number %"PRIu64
2633                        " or bitdepth %"PRIu64". Skipping track.\n",
2634                        track->audio.channels, track->audio.bitdepth);
2635                 if (matroska->ctx->error_recognition & AV_EF_EXPLODE)
2636                     return AVERROR_INVALIDDATA;
2637                 else
2638                     continue;
2639             }
2640             if (track->audio.out_samplerate < 0 || track->audio.out_samplerate > INT_MAX)
2641                 return AVERROR_INVALIDDATA;
2642             extradata_size = 22;
2643             extradata      = av_mallocz(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
2644             if (!extradata)
2645                 return AVERROR(ENOMEM);
2646             ptr = extradata;
2647             bytestream_put_be32(&ptr, AV_RB32("TTA1"));
2648             bytestream_put_le16(&ptr, 1);
2649             bytestream_put_le16(&ptr, track->audio.channels);
2650             bytestream_put_le16(&ptr, track->audio.bitdepth);
2651             bytestream_put_le32(&ptr, track->audio.out_samplerate);
2652             bytestream_put_le32(&ptr, av_rescale(matroska->duration * matroska->time_scale,
2653                                                  track->audio.out_samplerate,
2654                                                  AV_TIME_BASE * 1000));
2655         } else if (codec_id == AV_CODEC_ID_RV10 ||
2656                    codec_id == AV_CODEC_ID_RV20 ||
2657                    codec_id == AV_CODEC_ID_RV30 ||
2658                    codec_id == AV_CODEC_ID_RV40) {
2659             extradata_offset = 26;
2660         } else if (codec_id == AV_CODEC_ID_RA_144) {
2661             track->audio.out_samplerate = 8000;
2662             track->audio.channels       = 1;
2663         } else if ((codec_id == AV_CODEC_ID_RA_288 ||
2664                     codec_id == AV_CODEC_ID_COOK   ||
2665                     codec_id == AV_CODEC_ID_ATRAC3 ||
2666                     codec_id == AV_CODEC_ID_SIPR)
2667                       && track->codec_priv.data) {
2668             int flavor;
2669 
2670             ffio_init_context(&b, track->codec_priv.data,
2671                               track->codec_priv.size,
2672                               0, NULL, NULL, NULL, NULL);
2673             avio_skip(&b, 22);
2674             flavor                       = avio_rb16(&b);
2675             track->audio.coded_framesize = avio_rb32(&b);
2676             avio_skip(&b, 12);
2677             track->audio.sub_packet_h    = avio_rb16(&b);
2678             track->audio.frame_size      = avio_rb16(&b);
2679             track->audio.sub_packet_size = avio_rb16(&b);
2680             if (track->audio.coded_framesize <= 0 ||
2681                 track->audio.sub_packet_h    <= 0 ||
2682                 track->audio.frame_size      <= 0)
2683                 return AVERROR_INVALIDDATA;
2684 
2685             if (codec_id == AV_CODEC_ID_RA_288) {
2686                 if (track->audio.sub_packet_h & 1 || 2 * track->audio.frame_size
2687                     != (int64_t)track->audio.sub_packet_h * track->audio.coded_framesize)
2688                     return AVERROR_INVALIDDATA;
2689                 st->codecpar->block_align = track->audio.coded_framesize;
2690                 track->codec_priv.size = 0;
2691             } else {
2692                 if (codec_id == AV_CODEC_ID_SIPR) {
2693                     static const int sipr_bit_rate[4] = { 6504, 8496, 5000, 16000 };
2694                     if (flavor > 3)
2695                         return AVERROR_INVALIDDATA;
2696                     track->audio.sub_packet_size = ff_sipr_subpk_size[flavor];
2697                     st->codecpar->bit_rate          = sipr_bit_rate[flavor];
2698                 } else if (track->audio.sub_packet_size <= 0 ||
2699                            track->audio.frame_size % track->audio.sub_packet_size)
2700                     return AVERROR_INVALIDDATA;
2701                 st->codecpar->block_align = track->audio.sub_packet_size;
2702                 extradata_offset       = 78;
2703             }
2704             track->audio.buf = av_malloc_array(track->audio.sub_packet_h,
2705                                                track->audio.frame_size);
2706             if (!track->audio.buf)
2707                 return AVERROR(ENOMEM);
2708         } else if (codec_id == AV_CODEC_ID_FLAC && track->codec_priv.size) {
2709             ret = matroska_parse_flac(s, track, &extradata_offset);
2710             if (ret < 0)
2711                 return ret;
2712         } else if (codec_id == AV_CODEC_ID_WAVPACK && track->codec_priv.size < 2) {
2713             av_log(matroska->ctx, AV_LOG_INFO, "Assuming WavPack version 4.10 "
2714                    "in absence of valid CodecPrivate.\n");
2715             extradata_size = 2;
2716             extradata = av_mallocz(2 + AV_INPUT_BUFFER_PADDING_SIZE);
2717             if (!extradata)
2718                 return AVERROR(ENOMEM);
2719             AV_WL16(extradata, 0x410);
2720         } else if (codec_id == AV_CODEC_ID_PRORES && track->codec_priv.size == 4) {
2721             fourcc = AV_RL32(track->codec_priv.data);
2722         } else if (codec_id == AV_CODEC_ID_VP9 && track->codec_priv.size) {
2723             /* we don't need any value stored in CodecPrivate.
2724                make sure that it's not exported as extradata. */
2725             track->codec_priv.size = 0;
2726         } else if (codec_id == AV_CODEC_ID_AV1 && track->codec_priv.size) {
2727             /* For now, propagate only the OBUs, if any. Once libavcodec is
2728                updated to handle isobmff style extradata this can be removed. */
2729             extradata_offset = 4;
2730         }
2731         track->codec_priv.size -= extradata_offset;
2732 
2733         if (codec_id == AV_CODEC_ID_NONE)
2734             av_log(matroska->ctx, AV_LOG_INFO,
2735                    "Unknown/unsupported AVCodecID %s.\n", track->codec_id);
2736 
2737         if (track->time_scale < 0.01) {
2738             av_log(matroska->ctx, AV_LOG_WARNING,
2739                    "Track TimestampScale too small %f, assuming 1.0.\n",
2740                    track->time_scale);
2741             track->time_scale = 1.0;
2742         }
2743         avpriv_set_pts_info(st, 64, matroska->time_scale * track->time_scale,
2744                             1000 * 1000 * 1000);    /* 64 bit pts in ns */
2745 
2746         /* convert the delay from ns to the track timebase */
2747         track->codec_delay_in_track_tb = av_rescale_q(track->codec_delay,
2748                                           (AVRational){ 1, 1000000000 },
2749                                           st->time_base);
2750 
2751         st->codecpar->codec_id = codec_id;
2752 
2753         if (strcmp(track->language, "und"))
2754             av_dict_set(&st->metadata, "language", track->language, 0);
2755         av_dict_set(&st->metadata, "title", track->name, 0);
2756 
2757         if (track->flag_default)
2758             st->disposition |= AV_DISPOSITION_DEFAULT;
2759         if (track->flag_forced)
2760             st->disposition |= AV_DISPOSITION_FORCED;
2761         if (track->flag_comment)
2762             st->disposition |= AV_DISPOSITION_COMMENT;
2763         if (track->flag_hearingimpaired)
2764             st->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
2765         if (track->flag_visualimpaired)
2766             st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
2767         if (track->flag_original.count > 0)
2768             st->disposition |= track->flag_original.el.u ? AV_DISPOSITION_ORIGINAL
2769                                                          : AV_DISPOSITION_DUB;
2770 
2771         if (!st->codecpar->extradata) {
2772             if (extradata) {
2773                 st->codecpar->extradata      = extradata;
2774                 st->codecpar->extradata_size = extradata_size;
2775             } else if (track->codec_priv.data && track->codec_priv.size > 0) {
2776                 if (ff_alloc_extradata(st->codecpar, track->codec_priv.size))
2777                     return AVERROR(ENOMEM);
2778                 memcpy(st->codecpar->extradata,
2779                        track->codec_priv.data + extradata_offset,
2780                        track->codec_priv.size);
2781             }
2782         }
2783 
2784         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
2785             MatroskaTrackPlane *planes = track->operation.combine_planes.elem;
2786             int display_width_mul  = 1;
2787             int display_height_mul = 1;
2788 
2789             st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
2790             st->codecpar->codec_tag  = fourcc;
2791             if (bit_depth >= 0)
2792                 st->codecpar->bits_per_coded_sample = bit_depth;
2793             st->codecpar->width      = track->video.pixel_width;
2794             st->codecpar->height     = track->video.pixel_height;
2795 
2796             if (track->video.interlaced == MATROSKA_VIDEO_INTERLACE_FLAG_INTERLACED)
2797                 st->codecpar->field_order = mkv_field_order(matroska, track->video.field_order);
2798             else if (track->video.interlaced == MATROSKA_VIDEO_INTERLACE_FLAG_PROGRESSIVE)
2799                 st->codecpar->field_order = AV_FIELD_PROGRESSIVE;
2800 
2801             if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB)
2802                 mkv_stereo_mode_display_mul(track->video.stereo_mode, &display_width_mul, &display_height_mul);
2803 
2804             if (track->video.display_unit < MATROSKA_VIDEO_DISPLAYUNIT_UNKNOWN) {
2805                 av_reduce(&st->sample_aspect_ratio.num,
2806                           &st->sample_aspect_ratio.den,
2807                           st->codecpar->height * track->video.display_width  * display_width_mul,
2808                           st->codecpar->width  * track->video.display_height * display_height_mul,
2809                           255);
2810             }
2811             if (st->codecpar->codec_id != AV_CODEC_ID_HEVC)
2812                 st->need_parsing = AVSTREAM_PARSE_HEADERS;
2813 
2814             if (track->default_duration) {
2815                 int div = track->default_duration <= INT64_MAX ? 1 : 2;
2816                 av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
2817                           1000000000 / div, track->default_duration / div, 30000);
2818 #if FF_API_R_FRAME_RATE
2819                 if (   st->avg_frame_rate.num < st->avg_frame_rate.den * 1000LL
2820                     && st->avg_frame_rate.num > st->avg_frame_rate.den * 5LL)
2821                     st->r_frame_rate = st->avg_frame_rate;
2822 #endif
2823             }
2824 
2825             /* export stereo mode flag as metadata tag */
2826             if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB)
2827                 av_dict_set(&st->metadata, "stereo_mode", ff_matroska_video_stereo_mode[track->video.stereo_mode], 0);
2828 
2829             /* export alpha mode flag as metadata tag  */
2830             if (track->video.alpha_mode)
2831                 av_dict_set(&st->metadata, "alpha_mode", "1", 0);
2832 
2833             /* if we have virtual track, mark the real tracks */
2834             for (j=0; j < track->operation.combine_planes.nb_elem; j++) {
2835                 char buf[32];
2836                 if (planes[j].type >= MATROSKA_VIDEO_STEREO_PLANE_COUNT)
2837                     continue;
2838                 snprintf(buf, sizeof(buf), "%s_%d",
2839                          ff_matroska_video_stereo_plane[planes[j].type], i);
2840                 for (k=0; k < matroska->tracks.nb_elem; k++)
2841                     if (planes[j].uid == tracks[k].uid && tracks[k].stream) {
2842                         av_dict_set(&tracks[k].stream->metadata,
2843                                     "stereo_mode", buf, 0);
2844                         break;
2845                     }
2846             }
2847             // add stream level stereo3d side data if it is a supported format
2848             if (track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB &&
2849                 track->video.stereo_mode != 10 && track->video.stereo_mode != 12) {
2850                 int ret = ff_mkv_stereo3d_conv(st, track->video.stereo_mode);
2851                 if (ret < 0)
2852                     return ret;
2853             }
2854 
2855             ret = mkv_parse_video_color(st, track);
2856             if (ret < 0)
2857                 return ret;
2858             ret = mkv_parse_video_projection(st, track, matroska->ctx);
2859             if (ret < 0)
2860                 return ret;
2861         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
2862             st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
2863             st->codecpar->codec_tag   = fourcc;
2864             st->codecpar->sample_rate = track->audio.out_samplerate;
2865             st->codecpar->channels    = track->audio.channels;
2866             if (!st->codecpar->bits_per_coded_sample)
2867                 st->codecpar->bits_per_coded_sample = track->audio.bitdepth;
2868             if (st->codecpar->codec_id == AV_CODEC_ID_MP3 ||
2869                 st->codecpar->codec_id == AV_CODEC_ID_MLP ||
2870                 st->codecpar->codec_id == AV_CODEC_ID_TRUEHD)
2871                 st->need_parsing = AVSTREAM_PARSE_FULL;
2872             else if (st->codecpar->codec_id != AV_CODEC_ID_AAC)
2873                 st->need_parsing = AVSTREAM_PARSE_HEADERS;
2874             if (track->codec_delay > 0) {
2875                 st->codecpar->initial_padding = av_rescale_q(track->codec_delay,
2876                                                              (AVRational){1, 1000000000},
2877                                                              (AVRational){1, st->codecpar->codec_id == AV_CODEC_ID_OPUS ?
2878                                                                              48000 : st->codecpar->sample_rate});
2879             }
2880             if (track->seek_preroll > 0) {
2881                 st->codecpar->seek_preroll = av_rescale_q(track->seek_preroll,
2882                                                           (AVRational){1, 1000000000},
2883                                                           (AVRational){1, st->codecpar->sample_rate});
2884             }
2885         } else if (codec_id == AV_CODEC_ID_WEBVTT) {
2886             st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
2887 
2888             if (!strcmp(track->codec_id, "D_WEBVTT/CAPTIONS")) {
2889                 st->disposition |= AV_DISPOSITION_CAPTIONS;
2890             } else if (!strcmp(track->codec_id, "D_WEBVTT/DESCRIPTIONS")) {
2891                 st->disposition |= AV_DISPOSITION_DESCRIPTIONS;
2892             } else if (!strcmp(track->codec_id, "D_WEBVTT/METADATA")) {
2893                 st->disposition |= AV_DISPOSITION_METADATA;
2894             }
2895         } else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
2896             st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
2897 
2898             if (track->flag_textdescriptions)
2899                 st->disposition |= AV_DISPOSITION_DESCRIPTIONS;
2900         }
2901     }
2902 
2903     return 0;
2904 }
2905 
matroska_read_header(AVFormatContext * s)2906 static int matroska_read_header(AVFormatContext *s)
2907 {
2908     MatroskaDemuxContext *matroska = s->priv_data;
2909     EbmlList *attachments_list = &matroska->attachments;
2910     EbmlList *chapters_list    = &matroska->chapters;
2911     MatroskaAttachment *attachments;
2912     MatroskaChapter *chapters;
2913     uint64_t max_start = 0;
2914     int64_t pos;
2915     Ebml ebml = { 0 };
2916     int i, j, res;
2917 
2918     matroska->ctx = s;
2919     matroska->cues_parsing_deferred = 1;
2920 
2921     /* First read the EBML header. */
2922     if (ebml_parse(matroska, ebml_syntax, &ebml) || !ebml.doctype) {
2923         av_log(matroska->ctx, AV_LOG_ERROR, "EBML header parsing failed\n");
2924         ebml_free(ebml_syntax, &ebml);
2925         return AVERROR_INVALIDDATA;
2926     }
2927     if (ebml.version         > EBML_VERSION      ||
2928         ebml.max_size        > sizeof(uint64_t)  ||
2929         ebml.id_length       > sizeof(uint32_t)  ||
2930         ebml.doctype_version > 3) {
2931         avpriv_report_missing_feature(matroska->ctx,
2932                                       "EBML version %"PRIu64", doctype %s, doc version %"PRIu64,
2933                                       ebml.version, ebml.doctype, ebml.doctype_version);
2934         ebml_free(ebml_syntax, &ebml);
2935         return AVERROR_PATCHWELCOME;
2936     } else if (ebml.doctype_version == 3) {
2937         av_log(matroska->ctx, AV_LOG_WARNING,
2938                "EBML header using unsupported features\n"
2939                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
2940                ebml.version, ebml.doctype, ebml.doctype_version);
2941     }
2942     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++)
2943         if (!strcmp(ebml.doctype, matroska_doctypes[i]))
2944             break;
2945     if (i >= FF_ARRAY_ELEMS(matroska_doctypes)) {
2946         av_log(s, AV_LOG_WARNING, "Unknown EBML doctype '%s'\n", ebml.doctype);
2947         if (matroska->ctx->error_recognition & AV_EF_EXPLODE) {
2948             ebml_free(ebml_syntax, &ebml);
2949             return AVERROR_INVALIDDATA;
2950         }
2951     }
2952     ebml_free(ebml_syntax, &ebml);
2953 
2954     matroska->pkt = av_packet_alloc();
2955     if (!matroska->pkt)
2956         return AVERROR(ENOMEM);
2957 
2958     /* The next thing is a segment. */
2959     pos = avio_tell(matroska->ctx->pb);
2960     res = ebml_parse(matroska, matroska_segments, matroska);
2961     // Try resyncing until we find an EBML_STOP type element.
2962     while (res != 1) {
2963         res = matroska_resync(matroska, pos);
2964         if (res < 0)
2965             goto fail;
2966         pos = avio_tell(matroska->ctx->pb);
2967         res = ebml_parse(matroska, matroska_segment, matroska);
2968         if (res == AVERROR(EIO)) // EOF is translated to EIO, this exists the loop on EOF
2969             goto fail;
2970     }
2971     /* Set data_offset as it might be needed later by seek_frame_generic. */
2972     if (matroska->current_id == MATROSKA_ID_CLUSTER)
2973         s->internal->data_offset = avio_tell(matroska->ctx->pb) - 4;
2974     matroska_execute_seekhead(matroska);
2975 
2976     if (!matroska->time_scale)
2977         matroska->time_scale = 1000000;
2978     if (matroska->duration)
2979         matroska->ctx->duration = matroska->duration * matroska->time_scale *
2980                                   1000 / AV_TIME_BASE;
2981     av_dict_set(&s->metadata, "title", matroska->title, 0);
2982     av_dict_set(&s->metadata, "encoder", matroska->muxingapp, 0);
2983 
2984     if (matroska->date_utc.size == 8)
2985         matroska_metadata_creation_time(&s->metadata, AV_RB64(matroska->date_utc.data));
2986 
2987     res = matroska_parse_tracks(s);
2988     if (res < 0)
2989         goto fail;
2990 
2991     attachments = attachments_list->elem;
2992     for (j = 0; j < attachments_list->nb_elem; j++) {
2993         if (!(attachments[j].filename && attachments[j].mime &&
2994               attachments[j].bin.data && attachments[j].bin.size > 0)) {
2995             av_log(matroska->ctx, AV_LOG_ERROR, "incomplete attachment\n");
2996         } else {
2997             AVStream *st = avformat_new_stream(s, NULL);
2998             if (!st)
2999                 break;
3000             av_dict_set(&st->metadata, "filename", attachments[j].filename, 0);
3001             av_dict_set(&st->metadata, "mimetype", attachments[j].mime, 0);
3002             if (attachments[j].description)
3003                 av_dict_set(&st->metadata, "title", attachments[j].description, 0);
3004             st->codecpar->codec_id   = AV_CODEC_ID_NONE;
3005 
3006             for (i = 0; mkv_image_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
3007                 if (av_strstart(attachments[j].mime, mkv_image_mime_tags[i].str, NULL)) {
3008                     st->codecpar->codec_id = mkv_image_mime_tags[i].id;
3009                     break;
3010                 }
3011             }
3012 
3013             attachments[j].stream = st;
3014 
3015             if (st->codecpar->codec_id != AV_CODEC_ID_NONE) {
3016                 AVPacket *pkt = &st->attached_pic;
3017 
3018                 st->disposition         |= AV_DISPOSITION_ATTACHED_PIC;
3019                 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
3020 
3021                 av_packet_unref(pkt);
3022                 pkt->buf          = attachments[j].bin.buf;
3023                 attachments[j].bin.buf = NULL;
3024                 pkt->data         = attachments[j].bin.data;
3025                 pkt->size         = attachments[j].bin.size;
3026                 pkt->stream_index = st->index;
3027                 pkt->flags       |= AV_PKT_FLAG_KEY;
3028             } else {
3029                 st->codecpar->codec_type = AVMEDIA_TYPE_ATTACHMENT;
3030                 if (ff_alloc_extradata(st->codecpar, attachments[j].bin.size))
3031                     break;
3032                 memcpy(st->codecpar->extradata, attachments[j].bin.data,
3033                        attachments[j].bin.size);
3034 
3035                 for (i = 0; mkv_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
3036                     if (av_strstart(attachments[j].mime, mkv_mime_tags[i].str, NULL)) {
3037                         st->codecpar->codec_id = mkv_mime_tags[i].id;
3038                         break;
3039                     }
3040                 }
3041             }
3042         }
3043     }
3044 
3045     chapters = chapters_list->elem;
3046     for (i = 0; i < chapters_list->nb_elem; i++)
3047         if (chapters[i].start != AV_NOPTS_VALUE && chapters[i].uid &&
3048             (max_start == 0 || chapters[i].start > max_start)) {
3049             chapters[i].chapter =
3050                 avpriv_new_chapter(s, chapters[i].uid,
3051                                    (AVRational) { 1, 1000000000 },
3052                                    chapters[i].start, chapters[i].end,
3053                                    chapters[i].title);
3054             max_start = chapters[i].start;
3055         }
3056 
3057     matroska_add_index_entries(matroska);
3058 
3059     matroska_convert_tags(s);
3060 
3061     return 0;
3062 fail:
3063     matroska_read_close(s);
3064     return res;
3065 }
3066 
3067 /*
3068  * Put one packet in an application-supplied AVPacket struct.
3069  * Returns 0 on success or -1 on failure.
3070  */
matroska_deliver_packet(MatroskaDemuxContext * matroska,AVPacket * pkt)3071 static int matroska_deliver_packet(MatroskaDemuxContext *matroska,
3072                                    AVPacket *pkt)
3073 {
3074     if (matroska->queue) {
3075         MatroskaTrack *tracks = matroska->tracks.elem;
3076         MatroskaTrack *track;
3077 
3078         avpriv_packet_list_get(&matroska->queue, &matroska->queue_end, pkt);
3079         track = &tracks[pkt->stream_index];
3080         if (track->has_palette) {
3081             uint8_t *pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, AVPALETTE_SIZE);
3082             if (!pal) {
3083                 av_log(matroska->ctx, AV_LOG_ERROR, "Cannot append palette to packet\n");
3084             } else {
3085                 memcpy(pal, track->palette, AVPALETTE_SIZE);
3086             }
3087             track->has_palette = 0;
3088         }
3089         return 0;
3090     }
3091 
3092     return -1;
3093 }
3094 
3095 /*
3096  * Free all packets in our internal queue.
3097  */
matroska_clear_queue(MatroskaDemuxContext * matroska)3098 static void matroska_clear_queue(MatroskaDemuxContext *matroska)
3099 {
3100     avpriv_packet_list_free(&matroska->queue, &matroska->queue_end);
3101 }
3102 
matroska_parse_laces(MatroskaDemuxContext * matroska,uint8_t ** buf,int size,int type,AVIOContext * pb,uint32_t lace_size[256],int * laces)3103 static int matroska_parse_laces(MatroskaDemuxContext *matroska, uint8_t **buf,
3104                                 int size, int type, AVIOContext *pb,
3105                                 uint32_t lace_size[256], int *laces)
3106 {
3107     int n;
3108     uint8_t *data = *buf;
3109 
3110     if (!type) {
3111         *laces    = 1;
3112         lace_size[0] = size;
3113         return 0;
3114     }
3115 
3116     if (size <= 0)
3117         return AVERROR_INVALIDDATA;
3118 
3119     *laces = *data + 1;
3120     data  += 1;
3121     size  -= 1;
3122 
3123     switch (type) {
3124     case 0x1: /* Xiph lacing */
3125     {
3126         uint8_t temp;
3127         uint32_t total = 0;
3128         for (n = 0; n < *laces - 1; n++) {
3129             lace_size[n] = 0;
3130 
3131             do {
3132                 if (size <= total)
3133                     return AVERROR_INVALIDDATA;
3134                 temp          = *data;
3135                 total        += temp;
3136                 lace_size[n] += temp;
3137                 data         += 1;
3138                 size         -= 1;
3139             } while (temp ==  0xff);
3140         }
3141         if (size < total)
3142             return AVERROR_INVALIDDATA;
3143 
3144         lace_size[n] = size - total;
3145         break;
3146     }
3147 
3148     case 0x2: /* fixed-size lacing */
3149         if (size % (*laces))
3150             return AVERROR_INVALIDDATA;
3151         for (n = 0; n < *laces; n++)
3152             lace_size[n] = size / *laces;
3153         break;
3154 
3155     case 0x3: /* EBML lacing */
3156     {
3157         uint64_t num;
3158         uint64_t total;
3159         int offset;
3160 
3161         avio_skip(pb, 4);
3162 
3163         n = ebml_read_num(matroska, pb, 8, &num, 1);
3164         if (n < 0)
3165             return n;
3166         if (num > INT_MAX)
3167             return AVERROR_INVALIDDATA;
3168 
3169         total = lace_size[0] = num;
3170         offset = n;
3171         for (n = 1; n < *laces - 1; n++) {
3172             int64_t snum;
3173             int r;
3174             r = matroska_ebmlnum_sint(matroska, pb, &snum);
3175             if (r < 0)
3176                 return r;
3177             if (lace_size[n - 1] + snum > (uint64_t)INT_MAX)
3178                 return AVERROR_INVALIDDATA;
3179 
3180             lace_size[n] = lace_size[n - 1] + snum;
3181             total       += lace_size[n];
3182             offset      += r;
3183         }
3184         data += offset;
3185         size -= offset;
3186         if (size < total)
3187             return AVERROR_INVALIDDATA;
3188 
3189         lace_size[*laces - 1] = size - total;
3190         break;
3191     }
3192     }
3193 
3194     *buf = data;
3195 
3196     return 0;
3197 }
3198 
matroska_parse_rm_audio(MatroskaDemuxContext * matroska,MatroskaTrack * track,AVStream * st,uint8_t * data,int size,uint64_t timecode,int64_t pos)3199 static int matroska_parse_rm_audio(MatroskaDemuxContext *matroska,
3200                                    MatroskaTrack *track, AVStream *st,
3201                                    uint8_t *data, int size, uint64_t timecode,
3202                                    int64_t pos)
3203 {
3204     const int a   = st->codecpar->block_align;
3205     const int sps = track->audio.sub_packet_size;
3206     const int cfs = track->audio.coded_framesize;
3207     const int h   = track->audio.sub_packet_h;
3208     const int w   = track->audio.frame_size;
3209     int y   = track->audio.sub_packet_cnt;
3210     int x;
3211 
3212     if (!track->audio.pkt_cnt) {
3213         if (track->audio.sub_packet_cnt == 0)
3214             track->audio.buf_timecode = timecode;
3215         if (st->codecpar->codec_id == AV_CODEC_ID_RA_288) {
3216             if (size < cfs * h / 2) {
3217                 av_log(matroska->ctx, AV_LOG_ERROR,
3218                        "Corrupt int4 RM-style audio packet size\n");
3219                 return AVERROR_INVALIDDATA;
3220             }
3221             for (x = 0; x < h / 2; x++)
3222                 memcpy(track->audio.buf + x * 2 * w + y * cfs,
3223                        data + x * cfs, cfs);
3224         } else if (st->codecpar->codec_id == AV_CODEC_ID_SIPR) {
3225             if (size < w) {
3226                 av_log(matroska->ctx, AV_LOG_ERROR,
3227                        "Corrupt sipr RM-style audio packet size\n");
3228                 return AVERROR_INVALIDDATA;
3229             }
3230             memcpy(track->audio.buf + y * w, data, w);
3231         } else {
3232             if (size < w) {
3233                 av_log(matroska->ctx, AV_LOG_ERROR,
3234                        "Corrupt generic RM-style audio packet size\n");
3235                 return AVERROR_INVALIDDATA;
3236             }
3237             for (x = 0; x < w / sps; x++)
3238                 memcpy(track->audio.buf +
3239                        sps * (h * x + ((h + 1) / 2) * (y & 1) + (y >> 1)),
3240                        data + x * sps, sps);
3241         }
3242 
3243         if (++track->audio.sub_packet_cnt >= h) {
3244             if (st->codecpar->codec_id == AV_CODEC_ID_SIPR)
3245                 ff_rm_reorder_sipr_data(track->audio.buf, h, w);
3246             track->audio.sub_packet_cnt = 0;
3247             track->audio.pkt_cnt        = h * w / a;
3248         }
3249     }
3250 
3251     while (track->audio.pkt_cnt) {
3252         int ret;
3253         AVPacket *pkt = matroska->pkt;
3254 
3255         ret = av_new_packet(pkt, a);
3256         if (ret < 0) {
3257             return ret;
3258         }
3259         memcpy(pkt->data,
3260                track->audio.buf + a * (h * w / a - track->audio.pkt_cnt--),
3261                a);
3262         pkt->pts                  = track->audio.buf_timecode;
3263         track->audio.buf_timecode = AV_NOPTS_VALUE;
3264         pkt->pos                  = pos;
3265         pkt->stream_index         = st->index;
3266         ret = avpriv_packet_list_put(&matroska->queue, &matroska->queue_end, pkt, NULL, 0);
3267         if (ret < 0) {
3268             av_packet_unref(pkt);
3269             return AVERROR(ENOMEM);
3270         }
3271     }
3272 
3273     return 0;
3274 }
3275 
3276 /* reconstruct full wavpack blocks from mangled matroska ones */
matroska_parse_wavpack(MatroskaTrack * track,uint8_t ** data,int * size)3277 static int matroska_parse_wavpack(MatroskaTrack *track,
3278                                   uint8_t **data, int *size)
3279 {
3280     uint8_t *dst = NULL;
3281     uint8_t *src = *data;
3282     int dstlen   = 0;
3283     int srclen   = *size;
3284     uint32_t samples;
3285     uint16_t ver;
3286     int ret, offset = 0;
3287 
3288     if (srclen < 12)
3289         return AVERROR_INVALIDDATA;
3290 
3291     av_assert1(track->stream->codecpar->extradata_size >= 2);
3292     ver = AV_RL16(track->stream->codecpar->extradata);
3293 
3294     samples = AV_RL32(src);
3295     src    += 4;
3296     srclen -= 4;
3297 
3298     while (srclen >= 8) {
3299         int multiblock;
3300         uint32_t blocksize;
3301         uint8_t *tmp;
3302 
3303         uint32_t flags = AV_RL32(src);
3304         uint32_t crc   = AV_RL32(src + 4);
3305         src    += 8;
3306         srclen -= 8;
3307 
3308         multiblock = (flags & 0x1800) != 0x1800;
3309         if (multiblock) {
3310             if (srclen < 4) {
3311                 ret = AVERROR_INVALIDDATA;
3312                 goto fail;
3313             }
3314             blocksize = AV_RL32(src);
3315             src      += 4;
3316             srclen   -= 4;
3317         } else
3318             blocksize = srclen;
3319 
3320         if (blocksize > srclen) {
3321             ret = AVERROR_INVALIDDATA;
3322             goto fail;
3323         }
3324 
3325         tmp = av_realloc(dst, dstlen + blocksize + 32 + AV_INPUT_BUFFER_PADDING_SIZE);
3326         if (!tmp) {
3327             ret = AVERROR(ENOMEM);
3328             goto fail;
3329         }
3330         dst     = tmp;
3331         dstlen += blocksize + 32;
3332 
3333         AV_WL32(dst + offset, MKTAG('w', 'v', 'p', 'k'));   // tag
3334         AV_WL32(dst + offset +  4, blocksize + 24);         // blocksize - 8
3335         AV_WL16(dst + offset +  8, ver);                    // version
3336         AV_WL16(dst + offset + 10, 0);                      // track/index_no
3337         AV_WL32(dst + offset + 12, 0);                      // total samples
3338         AV_WL32(dst + offset + 16, 0);                      // block index
3339         AV_WL32(dst + offset + 20, samples);                // number of samples
3340         AV_WL32(dst + offset + 24, flags);                  // flags
3341         AV_WL32(dst + offset + 28, crc);                    // crc
3342         memcpy(dst + offset + 32, src, blocksize);          // block data
3343 
3344         src    += blocksize;
3345         srclen -= blocksize;
3346         offset += blocksize + 32;
3347     }
3348 
3349     memset(dst + dstlen, 0, AV_INPUT_BUFFER_PADDING_SIZE);
3350 
3351     *data = dst;
3352     *size = dstlen;
3353 
3354     return 0;
3355 
3356 fail:
3357     av_freep(&dst);
3358     return ret;
3359 }
3360 
matroska_parse_prores(MatroskaTrack * track,uint8_t ** data,int * size)3361 static int matroska_parse_prores(MatroskaTrack *track,
3362                                  uint8_t **data, int *size)
3363 {
3364     uint8_t *dst;
3365     int dstlen = *size + 8;
3366 
3367     dst = av_malloc(dstlen + AV_INPUT_BUFFER_PADDING_SIZE);
3368     if (!dst)
3369         return AVERROR(ENOMEM);
3370 
3371     AV_WB32(dst, dstlen);
3372     AV_WB32(dst + 4, MKBETAG('i', 'c', 'p', 'f'));
3373     memcpy(dst + 8, *data, dstlen - 8);
3374     memset(dst + dstlen, 0, AV_INPUT_BUFFER_PADDING_SIZE);
3375 
3376     *data = dst;
3377     *size = dstlen;
3378 
3379     return 0;
3380 }
3381 
matroska_parse_webvtt(MatroskaDemuxContext * matroska,MatroskaTrack * track,AVStream * st,uint8_t * data,int data_len,uint64_t timecode,uint64_t duration,int64_t pos)3382 static int matroska_parse_webvtt(MatroskaDemuxContext *matroska,
3383                                  MatroskaTrack *track,
3384                                  AVStream *st,
3385                                  uint8_t *data, int data_len,
3386                                  uint64_t timecode,
3387                                  uint64_t duration,
3388                                  int64_t pos)
3389 {
3390     AVPacket *pkt = matroska->pkt;
3391     uint8_t *id, *settings, *text, *buf;
3392     int id_len, settings_len, text_len;
3393     uint8_t *p, *q;
3394     int err;
3395 
3396     if (data_len <= 0)
3397         return AVERROR_INVALIDDATA;
3398 
3399     p = data;
3400     q = data + data_len;
3401 
3402     id = p;
3403     id_len = -1;
3404     while (p < q) {
3405         if (*p == '\r' || *p == '\n') {
3406             id_len = p - id;
3407             if (*p == '\r')
3408                 p++;
3409             break;
3410         }
3411         p++;
3412     }
3413 
3414     if (p >= q || *p != '\n')
3415         return AVERROR_INVALIDDATA;
3416     p++;
3417 
3418     settings = p;
3419     settings_len = -1;
3420     while (p < q) {
3421         if (*p == '\r' || *p == '\n') {
3422             settings_len = p - settings;
3423             if (*p == '\r')
3424                 p++;
3425             break;
3426         }
3427         p++;
3428     }
3429 
3430     if (p >= q || *p != '\n')
3431         return AVERROR_INVALIDDATA;
3432     p++;
3433 
3434     text = p;
3435     text_len = q - p;
3436     while (text_len > 0) {
3437         const int len = text_len - 1;
3438         const uint8_t c = p[len];
3439         if (c != '\r' && c != '\n')
3440             break;
3441         text_len = len;
3442     }
3443 
3444     if (text_len <= 0)
3445         return AVERROR_INVALIDDATA;
3446 
3447     err = av_new_packet(pkt, text_len);
3448     if (err < 0) {
3449         return err;
3450     }
3451 
3452     memcpy(pkt->data, text, text_len);
3453 
3454     if (id_len > 0) {
3455         buf = av_packet_new_side_data(pkt,
3456                                       AV_PKT_DATA_WEBVTT_IDENTIFIER,
3457                                       id_len);
3458         if (!buf) {
3459             av_packet_unref(pkt);
3460             return AVERROR(ENOMEM);
3461         }
3462         memcpy(buf, id, id_len);
3463     }
3464 
3465     if (settings_len > 0) {
3466         buf = av_packet_new_side_data(pkt,
3467                                       AV_PKT_DATA_WEBVTT_SETTINGS,
3468                                       settings_len);
3469         if (!buf) {
3470             av_packet_unref(pkt);
3471             return AVERROR(ENOMEM);
3472         }
3473         memcpy(buf, settings, settings_len);
3474     }
3475 
3476     // Do we need this for subtitles?
3477     // pkt->flags = AV_PKT_FLAG_KEY;
3478 
3479     pkt->stream_index = st->index;
3480     pkt->pts = timecode;
3481 
3482     // Do we need this for subtitles?
3483     // pkt->dts = timecode;
3484 
3485     pkt->duration = duration;
3486     pkt->pos = pos;
3487 
3488     err = avpriv_packet_list_put(&matroska->queue, &matroska->queue_end, pkt, NULL, 0);
3489     if (err < 0) {
3490         av_packet_unref(pkt);
3491         return AVERROR(ENOMEM);
3492     }
3493 
3494     return 0;
3495 }
3496 
matroska_parse_frame(MatroskaDemuxContext * matroska,MatroskaTrack * track,AVStream * st,AVBufferRef * buf,uint8_t * data,int pkt_size,uint64_t timecode,uint64_t lace_duration,int64_t pos,int is_keyframe,uint8_t * additional,uint64_t additional_id,int additional_size,int64_t discard_padding)3497 static int matroska_parse_frame(MatroskaDemuxContext *matroska,
3498                                 MatroskaTrack *track, AVStream *st,
3499                                 AVBufferRef *buf, uint8_t *data, int pkt_size,
3500                                 uint64_t timecode, uint64_t lace_duration,
3501                                 int64_t pos, int is_keyframe,
3502                                 uint8_t *additional, uint64_t additional_id, int additional_size,
3503                                 int64_t discard_padding)
3504 {
3505     uint8_t *pkt_data = data;
3506     int res = 0;
3507     AVPacket *pkt = matroska->pkt;
3508 
3509     if (st->codecpar->codec_id == AV_CODEC_ID_WAVPACK) {
3510         res = matroska_parse_wavpack(track, &pkt_data, &pkt_size);
3511         if (res < 0) {
3512             av_log(matroska->ctx, AV_LOG_ERROR,
3513                    "Error parsing a wavpack block.\n");
3514             goto fail;
3515         }
3516         if (!buf)
3517             av_freep(&data);
3518         buf = NULL;
3519     }
3520 
3521     if (st->codecpar->codec_id == AV_CODEC_ID_PRORES &&
3522         AV_RB32(pkt_data + 4)  != MKBETAG('i', 'c', 'p', 'f')) {
3523         res = matroska_parse_prores(track, &pkt_data, &pkt_size);
3524         if (res < 0) {
3525             av_log(matroska->ctx, AV_LOG_ERROR,
3526                    "Error parsing a prores block.\n");
3527             goto fail;
3528         }
3529         if (!buf)
3530             av_freep(&data);
3531         buf = NULL;
3532     }
3533 
3534     if (!pkt_size && !additional_size)
3535         goto no_output;
3536 
3537     av_packet_unref(pkt);
3538     if (!buf)
3539         pkt->buf = av_buffer_create(pkt_data, pkt_size + AV_INPUT_BUFFER_PADDING_SIZE,
3540                                     NULL, NULL, 0);
3541     else
3542         pkt->buf = av_buffer_ref(buf);
3543 
3544     if (!pkt->buf) {
3545         res = AVERROR(ENOMEM);
3546         goto fail;
3547     }
3548 
3549     pkt->data         = pkt_data;
3550     pkt->size         = pkt_size;
3551     pkt->flags        = is_keyframe;
3552     pkt->stream_index = st->index;
3553 
3554     if (additional_size > 0) {
3555         uint8_t *side_data = av_packet_new_side_data(pkt,
3556                                                      AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
3557                                                      additional_size + 8);
3558         if (!side_data) {
3559             av_packet_unref(pkt);
3560             return AVERROR(ENOMEM);
3561         }
3562         AV_WB64(side_data, additional_id);
3563         memcpy(side_data + 8, additional, additional_size);
3564     }
3565 
3566     if (discard_padding) {
3567         uint8_t *side_data = av_packet_new_side_data(pkt,
3568                                                      AV_PKT_DATA_SKIP_SAMPLES,
3569                                                      10);
3570         if (!side_data) {
3571             av_packet_unref(pkt);
3572             return AVERROR(ENOMEM);
3573         }
3574         discard_padding = av_rescale_q(discard_padding,
3575                                             (AVRational){1, 1000000000},
3576                                             (AVRational){1, st->codecpar->sample_rate});
3577         if (discard_padding > 0) {
3578             AV_WL32(side_data + 4, discard_padding);
3579         } else {
3580             AV_WL32(side_data, -discard_padding);
3581         }
3582     }
3583 
3584     if (track->ms_compat)
3585         pkt->dts = timecode;
3586     else
3587         pkt->pts = timecode;
3588     pkt->pos = pos;
3589     pkt->duration = lace_duration;
3590 
3591 #if FF_API_CONVERGENCE_DURATION
3592 FF_DISABLE_DEPRECATION_WARNINGS
3593     if (st->codecpar->codec_id == AV_CODEC_ID_SUBRIP) {
3594         pkt->convergence_duration = lace_duration;
3595     }
3596 FF_ENABLE_DEPRECATION_WARNINGS
3597 #endif
3598 
3599     res = avpriv_packet_list_put(&matroska->queue, &matroska->queue_end, pkt, NULL, 0);
3600     if (res < 0) {
3601         av_packet_unref(pkt);
3602         return AVERROR(ENOMEM);
3603     }
3604 
3605     return 0;
3606 
3607 no_output:
3608 fail:
3609     if (!buf)
3610         av_free(pkt_data);
3611     return res;
3612 }
3613 
matroska_parse_block(MatroskaDemuxContext * matroska,AVBufferRef * buf,uint8_t * data,int size,int64_t pos,uint64_t cluster_time,uint64_t block_duration,int is_keyframe,uint8_t * additional,uint64_t additional_id,int additional_size,int64_t cluster_pos,int64_t discard_padding)3614 static int matroska_parse_block(MatroskaDemuxContext *matroska, AVBufferRef *buf, uint8_t *data,
3615                                 int size, int64_t pos, uint64_t cluster_time,
3616                                 uint64_t block_duration, int is_keyframe,
3617                                 uint8_t *additional, uint64_t additional_id, int additional_size,
3618                                 int64_t cluster_pos, int64_t discard_padding)
3619 {
3620     uint64_t timecode = AV_NOPTS_VALUE;
3621     MatroskaTrack *track;
3622     AVIOContext pb;
3623     int res = 0;
3624     AVStream *st;
3625     int16_t block_time;
3626     uint32_t lace_size[256];
3627     int n, flags, laces = 0;
3628     uint64_t num;
3629     int trust_default_duration;
3630 
3631     ffio_init_context(&pb, data, size, 0, NULL, NULL, NULL, NULL);
3632 
3633     if ((n = ebml_read_num(matroska, &pb, 8, &num, 1)) < 0)
3634         return n;
3635     data += n;
3636     size -= n;
3637 
3638     track = matroska_find_track_by_num(matroska, num);
3639     if (!track || size < 3)
3640         return AVERROR_INVALIDDATA;
3641 
3642     if (!(st = track->stream)) {
3643         av_log(matroska->ctx, AV_LOG_VERBOSE,
3644                "No stream associated to TrackNumber %"PRIu64". "
3645                "Ignoring Block with this TrackNumber.\n", num);
3646         return 0;
3647     }
3648 
3649     if (st->discard >= AVDISCARD_ALL)
3650         return res;
3651     if (block_duration > INT64_MAX)
3652         block_duration = INT64_MAX;
3653 
3654     block_time = sign_extend(AV_RB16(data), 16);
3655     data      += 2;
3656     flags      = *data++;
3657     size      -= 3;
3658     if (is_keyframe == -1)
3659         is_keyframe = flags & 0x80 ? AV_PKT_FLAG_KEY : 0;
3660 
3661     if (cluster_time != (uint64_t) -1 &&
3662         (block_time >= 0 || cluster_time >= -block_time)) {
3663         uint64_t timecode_cluster_in_track_tb = (double) cluster_time / track->time_scale;
3664         timecode = timecode_cluster_in_track_tb + block_time - track->codec_delay_in_track_tb;
3665         if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE &&
3666             timecode < track->end_timecode)
3667             is_keyframe = 0;  /* overlapping subtitles are not key frame */
3668         if (is_keyframe) {
3669             ff_reduce_index(matroska->ctx, st->index);
3670             av_add_index_entry(st, cluster_pos, timecode, 0, 0,
3671                                AVINDEX_KEYFRAME);
3672         }
3673     }
3674 
3675     if (matroska->skip_to_keyframe &&
3676         track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
3677         // Compare signed timecodes. Timecode may be negative due to codec delay
3678         // offset. We don't support timestamps greater than int64_t anyway - see
3679         // AVPacket's pts.
3680         if ((int64_t)timecode < (int64_t)matroska->skip_to_timecode)
3681             return res;
3682         if (is_keyframe)
3683             matroska->skip_to_keyframe = 0;
3684         else if (!st->internal->skip_to_keyframe) {
3685             av_log(matroska->ctx, AV_LOG_ERROR, "File is broken, keyframes not correctly marked!\n");
3686             matroska->skip_to_keyframe = 0;
3687         }
3688     }
3689 
3690     res = matroska_parse_laces(matroska, &data, size, (flags & 0x06) >> 1,
3691                                &pb, lace_size, &laces);
3692     if (res < 0) {
3693         av_log(matroska->ctx, AV_LOG_ERROR, "Error parsing frame sizes.\n");
3694         return res;
3695     }
3696 
3697     trust_default_duration = track->default_duration != 0;
3698     if (track->audio.samplerate == 8000 && trust_default_duration) {
3699         // If this is needed for more codecs, then add them here
3700         if (st->codecpar->codec_id == AV_CODEC_ID_AC3) {
3701             if (track->audio.samplerate != st->codecpar->sample_rate || !st->codecpar->frame_size)
3702                 trust_default_duration = 0;
3703         }
3704     }
3705 
3706     if (!block_duration && trust_default_duration)
3707         block_duration = track->default_duration * laces / matroska->time_scale;
3708 
3709     if (cluster_time != (uint64_t)-1 && (block_time >= 0 || cluster_time >= -block_time))
3710         track->end_timecode =
3711             FFMAX(track->end_timecode, timecode + block_duration);
3712 
3713     for (n = 0; n < laces; n++) {
3714         int64_t lace_duration = block_duration*(n+1) / laces - block_duration*n / laces;
3715         uint8_t *out_data = data;
3716         int      out_size = lace_size[n];
3717 
3718         if (track->needs_decoding) {
3719             res = matroska_decode_buffer(&out_data, &out_size, track);
3720             if (res < 0)
3721                 return res;
3722             /* Given that we are here means that out_data is no longer
3723              * owned by buf, so set it to NULL. This depends upon
3724              * zero-length header removal compression being ignored. */
3725             av_assert1(out_data != data);
3726             buf = NULL;
3727         }
3728 
3729         if (track->audio.buf) {
3730             res = matroska_parse_rm_audio(matroska, track, st,
3731                                           out_data, out_size,
3732                                           timecode, pos);
3733             if (!buf)
3734                 av_free(out_data);
3735             if (res)
3736                 return res;
3737         } else if (st->codecpar->codec_id == AV_CODEC_ID_WEBVTT) {
3738             res = matroska_parse_webvtt(matroska, track, st,
3739                                         out_data, out_size,
3740                                         timecode, lace_duration,
3741                                         pos);
3742             if (!buf)
3743                 av_free(out_data);
3744             if (res)
3745                 return res;
3746         } else {
3747             res = matroska_parse_frame(matroska, track, st, buf, out_data,
3748                                        out_size, timecode, lace_duration,
3749                                        pos, !n ? is_keyframe : 0,
3750                                        additional, additional_id, additional_size,
3751                                        discard_padding);
3752             if (res)
3753                 return res;
3754         }
3755 
3756         if (timecode != AV_NOPTS_VALUE)
3757             timecode = lace_duration ? timecode + lace_duration : AV_NOPTS_VALUE;
3758         data += lace_size[n];
3759     }
3760 
3761     return 0;
3762 }
3763 
matroska_parse_cluster(MatroskaDemuxContext * matroska)3764 static int matroska_parse_cluster(MatroskaDemuxContext *matroska)
3765 {
3766     MatroskaCluster *cluster = &matroska->current_cluster;
3767     MatroskaBlock     *block = &cluster->block;
3768     int res;
3769 
3770     av_assert0(matroska->num_levels <= 2);
3771 
3772     if (matroska->num_levels == 1) {
3773         res = ebml_parse(matroska, matroska_segment, NULL);
3774 
3775         if (res == 1) {
3776             /* Found a cluster: subtract the size of the ID already read. */
3777             cluster->pos = avio_tell(matroska->ctx->pb) - 4;
3778 
3779             res = ebml_parse(matroska, matroska_cluster_enter, cluster);
3780             if (res < 0)
3781                 return res;
3782         }
3783     }
3784 
3785     if (matroska->num_levels == 2) {
3786         /* We are inside a cluster. */
3787         res = ebml_parse(matroska, matroska_cluster_parsing, cluster);
3788 
3789         if (res >= 0 && block->bin.size > 0) {
3790             int is_keyframe = block->non_simple ? block->reference.count == 0 : -1;
3791             uint8_t* additional = block->additional.size > 0 ?
3792                                     block->additional.data : NULL;
3793 
3794             res = matroska_parse_block(matroska, block->bin.buf, block->bin.data,
3795                                        block->bin.size, block->bin.pos,
3796                                        cluster->timecode, block->duration,
3797                                        is_keyframe, additional, block->additional_id,
3798                                        block->additional.size, cluster->pos,
3799                                        block->discard_padding);
3800         }
3801 
3802         ebml_free(matroska_blockgroup, block);
3803         memset(block, 0, sizeof(*block));
3804     } else if (!matroska->num_levels) {
3805         if (!avio_feof(matroska->ctx->pb)) {
3806             avio_r8(matroska->ctx->pb);
3807             if (!avio_feof(matroska->ctx->pb)) {
3808                 av_log(matroska->ctx, AV_LOG_WARNING, "File extends beyond "
3809                        "end of segment.\n");
3810                 return AVERROR_INVALIDDATA;
3811             }
3812         }
3813         matroska->done = 1;
3814         return AVERROR_EOF;
3815     }
3816 
3817     return res;
3818 }
3819 
matroska_read_packet(AVFormatContext * s,AVPacket * pkt)3820 static int matroska_read_packet(AVFormatContext *s, AVPacket *pkt)
3821 {
3822     MatroskaDemuxContext *matroska = s->priv_data;
3823     int ret = 0;
3824 
3825     if (matroska->resync_pos == -1) {
3826         // This can only happen if generic seeking has been used.
3827         matroska->resync_pos = avio_tell(s->pb);
3828     }
3829 
3830     while (matroska_deliver_packet(matroska, pkt)) {
3831         if (matroska->done)
3832             return (ret < 0) ? ret : AVERROR_EOF;
3833         if (matroska_parse_cluster(matroska) < 0 && !matroska->done)
3834             ret = matroska_resync(matroska, matroska->resync_pos);
3835     }
3836 
3837     return 0;
3838 }
3839 
matroska_read_seek(AVFormatContext * s,int stream_index,int64_t timestamp,int flags)3840 static int matroska_read_seek(AVFormatContext *s, int stream_index,
3841                               int64_t timestamp, int flags)
3842 {
3843     MatroskaDemuxContext *matroska = s->priv_data;
3844     MatroskaTrack *tracks = NULL;
3845     AVStream *st = s->streams[stream_index];
3846     int i, index;
3847 
3848     /* Parse the CUES now since we need the index data to seek. */
3849     if (matroska->cues_parsing_deferred > 0) {
3850         matroska->cues_parsing_deferred = 0;
3851         matroska_parse_cues(matroska);
3852     }
3853 
3854     if (!st->nb_index_entries)
3855         goto err;
3856     timestamp = FFMAX(timestamp, st->index_entries[0].timestamp);
3857 
3858     if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->nb_index_entries - 1) {
3859         matroska_reset_status(matroska, 0, st->index_entries[st->nb_index_entries - 1].pos);
3860         while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->nb_index_entries - 1) {
3861             matroska_clear_queue(matroska);
3862             if (matroska_parse_cluster(matroska) < 0)
3863                 break;
3864         }
3865     }
3866 
3867     matroska_clear_queue(matroska);
3868     if (index < 0 || (matroska->cues_parsing_deferred < 0 && index == st->nb_index_entries - 1))
3869         goto err;
3870 
3871     tracks = matroska->tracks.elem;
3872     for (i = 0; i < matroska->tracks.nb_elem; i++) {
3873         tracks[i].audio.pkt_cnt        = 0;
3874         tracks[i].audio.sub_packet_cnt = 0;
3875         tracks[i].audio.buf_timecode   = AV_NOPTS_VALUE;
3876         tracks[i].end_timecode         = 0;
3877     }
3878 
3879     /* We seek to a level 1 element, so set the appropriate status. */
3880     matroska_reset_status(matroska, 0, st->index_entries[index].pos);
3881     if (flags & AVSEEK_FLAG_ANY) {
3882         st->internal->skip_to_keyframe = 0;
3883         matroska->skip_to_timecode = timestamp;
3884     } else {
3885         st->internal->skip_to_keyframe = 1;
3886         matroska->skip_to_timecode = st->index_entries[index].timestamp;
3887     }
3888     matroska->skip_to_keyframe = 1;
3889     matroska->done             = 0;
3890     ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
3891     return 0;
3892 err:
3893     // slightly hackish but allows proper fallback to
3894     // the generic seeking code.
3895     matroska_reset_status(matroska, 0, -1);
3896     matroska->resync_pos = -1;
3897     matroska_clear_queue(matroska);
3898     st->internal->skip_to_keyframe =
3899     matroska->skip_to_keyframe = 0;
3900     matroska->done = 0;
3901     return -1;
3902 }
3903 
matroska_read_close(AVFormatContext * s)3904 static int matroska_read_close(AVFormatContext *s)
3905 {
3906     MatroskaDemuxContext *matroska = s->priv_data;
3907     MatroskaTrack *tracks = matroska->tracks.elem;
3908     int n;
3909 
3910     matroska_clear_queue(matroska);
3911     av_packet_free(&matroska->pkt);
3912 
3913     for (n = 0; n < matroska->tracks.nb_elem; n++)
3914         if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)
3915             av_freep(&tracks[n].audio.buf);
3916     ebml_free(matroska_segment, matroska);
3917 
3918     return 0;
3919 }
3920 
3921 typedef struct {
3922     int64_t start_time_ns;
3923     int64_t end_time_ns;
3924     int64_t start_offset;
3925     int64_t end_offset;
3926 } CueDesc;
3927 
3928 /* This function searches all the Cues and returns the CueDesc corresponding to
3929  * the timestamp ts. Returned CueDesc will be such that start_time_ns <= ts <
3930  * end_time_ns. All 4 fields will be set to -1 if ts >= file's duration.
3931  */
get_cue_desc(AVFormatContext * s,int64_t ts,int64_t cues_start)3932 static CueDesc get_cue_desc(AVFormatContext *s, int64_t ts, int64_t cues_start) {
3933     MatroskaDemuxContext *matroska = s->priv_data;
3934     CueDesc cue_desc;
3935     int i;
3936     int nb_index_entries = s->streams[0]->nb_index_entries;
3937     AVIndexEntry *index_entries = s->streams[0]->index_entries;
3938     if (ts >= matroska->duration * matroska->time_scale) return (CueDesc) {-1, -1, -1, -1};
3939     for (i = 1; i < nb_index_entries; i++) {
3940         if (index_entries[i - 1].timestamp * matroska->time_scale <= ts &&
3941             index_entries[i].timestamp * matroska->time_scale > ts) {
3942             break;
3943         }
3944     }
3945     --i;
3946     cue_desc.start_time_ns = index_entries[i].timestamp * matroska->time_scale;
3947     cue_desc.start_offset = index_entries[i].pos - matroska->segment_start;
3948     if (i != nb_index_entries - 1) {
3949         cue_desc.end_time_ns = index_entries[i + 1].timestamp * matroska->time_scale;
3950         cue_desc.end_offset = index_entries[i + 1].pos - matroska->segment_start;
3951     } else {
3952         cue_desc.end_time_ns = matroska->duration * matroska->time_scale;
3953         // FIXME: this needs special handling for files where Cues appear
3954         // before Clusters. the current logic assumes Cues appear after
3955         // Clusters.
3956         cue_desc.end_offset = cues_start - matroska->segment_start;
3957     }
3958     return cue_desc;
3959 }
3960 
webm_clusters_start_with_keyframe(AVFormatContext * s)3961 static int webm_clusters_start_with_keyframe(AVFormatContext *s)
3962 {
3963     MatroskaDemuxContext *matroska = s->priv_data;
3964     uint32_t id = matroska->current_id;
3965     int64_t cluster_pos, before_pos;
3966     int index, rv = 1;
3967     if (s->streams[0]->nb_index_entries <= 0) return 0;
3968     // seek to the first cluster using cues.
3969     index = av_index_search_timestamp(s->streams[0], 0, 0);
3970     if (index < 0)  return 0;
3971     cluster_pos = s->streams[0]->index_entries[index].pos;
3972     before_pos = avio_tell(s->pb);
3973     while (1) {
3974         uint64_t cluster_id, cluster_length;
3975         int read;
3976         AVPacket *pkt;
3977         avio_seek(s->pb, cluster_pos, SEEK_SET);
3978         // read cluster id and length
3979         read = ebml_read_num(matroska, matroska->ctx->pb, 4, &cluster_id, 1);
3980         if (read < 0 || cluster_id != 0xF43B675) // done with all clusters
3981             break;
3982         read = ebml_read_length(matroska, matroska->ctx->pb, &cluster_length);
3983         if (read < 0)
3984             break;
3985 
3986         matroska_reset_status(matroska, 0, cluster_pos);
3987         matroska_clear_queue(matroska);
3988         if (matroska_parse_cluster(matroska) < 0 ||
3989             !matroska->queue) {
3990             break;
3991         }
3992         pkt = &matroska->queue->pkt;
3993         // 4 + read is the length of the cluster id and the cluster length field.
3994         cluster_pos += 4 + read + cluster_length;
3995         if (!(pkt->flags & AV_PKT_FLAG_KEY)) {
3996             rv = 0;
3997             break;
3998         }
3999     }
4000 
4001     /* Restore the status after matroska_read_header: */
4002     matroska_reset_status(matroska, id, before_pos);
4003 
4004     return rv;
4005 }
4006 
buffer_size_after_time_downloaded(int64_t time_ns,double search_sec,int64_t bps,double min_buffer,double * buffer,double * sec_to_download,AVFormatContext * s,int64_t cues_start)4007 static int buffer_size_after_time_downloaded(int64_t time_ns, double search_sec, int64_t bps,
4008                                              double min_buffer, double* buffer,
4009                                              double* sec_to_download, AVFormatContext *s,
4010                                              int64_t cues_start)
4011 {
4012     double nano_seconds_per_second = 1000000000.0;
4013     double time_sec = time_ns / nano_seconds_per_second;
4014     int rv = 0;
4015     int64_t time_to_search_ns = (int64_t)(search_sec * nano_seconds_per_second);
4016     int64_t end_time_ns = time_ns + time_to_search_ns;
4017     double sec_downloaded = 0.0;
4018     CueDesc desc_curr = get_cue_desc(s, time_ns, cues_start);
4019     if (desc_curr.start_time_ns == -1)
4020       return -1;
4021     *sec_to_download = 0.0;
4022 
4023     // Check for non cue start time.
4024     if (time_ns > desc_curr.start_time_ns) {
4025       int64_t cue_nano = desc_curr.end_time_ns - time_ns;
4026       double percent = (double)(cue_nano) / (desc_curr.end_time_ns - desc_curr.start_time_ns);
4027       double cueBytes = (desc_curr.end_offset - desc_curr.start_offset) * percent;
4028       double timeToDownload = (cueBytes * 8.0) / bps;
4029 
4030       sec_downloaded += (cue_nano / nano_seconds_per_second) - timeToDownload;
4031       *sec_to_download += timeToDownload;
4032 
4033       // Check if the search ends within the first cue.
4034       if (desc_curr.end_time_ns >= end_time_ns) {
4035           double desc_end_time_sec = desc_curr.end_time_ns / nano_seconds_per_second;
4036           double percent_to_sub = search_sec / (desc_end_time_sec - time_sec);
4037           sec_downloaded = percent_to_sub * sec_downloaded;
4038           *sec_to_download = percent_to_sub * *sec_to_download;
4039       }
4040 
4041       if ((sec_downloaded + *buffer) <= min_buffer) {
4042           return 1;
4043       }
4044 
4045       // Get the next Cue.
4046       desc_curr = get_cue_desc(s, desc_curr.end_time_ns, cues_start);
4047     }
4048 
4049     while (desc_curr.start_time_ns != -1) {
4050         int64_t desc_bytes = desc_curr.end_offset - desc_curr.start_offset;
4051         int64_t desc_ns = desc_curr.end_time_ns - desc_curr.start_time_ns;
4052         double desc_sec = desc_ns / nano_seconds_per_second;
4053         double bits = (desc_bytes * 8.0);
4054         double time_to_download = bits / bps;
4055 
4056         sec_downloaded += desc_sec - time_to_download;
4057         *sec_to_download += time_to_download;
4058 
4059         if (desc_curr.end_time_ns >= end_time_ns) {
4060             double desc_end_time_sec = desc_curr.end_time_ns / nano_seconds_per_second;
4061             double percent_to_sub = search_sec / (desc_end_time_sec - time_sec);
4062             sec_downloaded = percent_to_sub * sec_downloaded;
4063             *sec_to_download = percent_to_sub * *sec_to_download;
4064 
4065             if ((sec_downloaded + *buffer) <= min_buffer)
4066                 rv = 1;
4067             break;
4068         }
4069 
4070         if ((sec_downloaded + *buffer) <= min_buffer) {
4071             rv = 1;
4072             break;
4073         }
4074 
4075         desc_curr = get_cue_desc(s, desc_curr.end_time_ns, cues_start);
4076     }
4077     *buffer = *buffer + sec_downloaded;
4078     return rv;
4079 }
4080 
4081 /* This function computes the bandwidth of the WebM file with the help of
4082  * buffer_size_after_time_downloaded() function. Both of these functions are
4083  * adapted from WebM Tools project and are adapted to work with FFmpeg's
4084  * Matroska parsing mechanism.
4085  *
4086  * Returns the bandwidth of the file on success; -1 on error.
4087  * */
webm_dash_manifest_compute_bandwidth(AVFormatContext * s,int64_t cues_start)4088 static int64_t webm_dash_manifest_compute_bandwidth(AVFormatContext *s, int64_t cues_start)
4089 {
4090     MatroskaDemuxContext *matroska = s->priv_data;
4091     AVStream *st = s->streams[0];
4092     double bandwidth = 0.0;
4093     int i;
4094 
4095     for (i = 0; i < st->nb_index_entries; i++) {
4096         int64_t prebuffer_ns = 1000000000;
4097         int64_t time_ns = st->index_entries[i].timestamp * matroska->time_scale;
4098         double nano_seconds_per_second = 1000000000.0;
4099         int64_t prebuffered_ns = time_ns + prebuffer_ns;
4100         double prebuffer_bytes = 0.0;
4101         int64_t temp_prebuffer_ns = prebuffer_ns;
4102         int64_t pre_bytes, pre_ns;
4103         double pre_sec, prebuffer, bits_per_second;
4104         CueDesc desc_beg = get_cue_desc(s, time_ns, cues_start);
4105 
4106         // Start with the first Cue.
4107         CueDesc desc_end = desc_beg;
4108 
4109         // Figure out how much data we have downloaded for the prebuffer. This will
4110         // be used later to adjust the bits per sample to try.
4111         while (desc_end.start_time_ns != -1 && desc_end.end_time_ns < prebuffered_ns) {
4112             // Prebuffered the entire Cue.
4113             prebuffer_bytes += desc_end.end_offset - desc_end.start_offset;
4114             temp_prebuffer_ns -= desc_end.end_time_ns - desc_end.start_time_ns;
4115             desc_end = get_cue_desc(s, desc_end.end_time_ns, cues_start);
4116         }
4117         if (desc_end.start_time_ns == -1) {
4118             // The prebuffer is larger than the duration.
4119             if (matroska->duration * matroska->time_scale >= prebuffered_ns)
4120               return -1;
4121             bits_per_second = 0.0;
4122         } else {
4123             // The prebuffer ends in the last Cue. Estimate how much data was
4124             // prebuffered.
4125             pre_bytes = desc_end.end_offset - desc_end.start_offset;
4126             pre_ns = desc_end.end_time_ns - desc_end.start_time_ns;
4127             pre_sec = pre_ns / nano_seconds_per_second;
4128             prebuffer_bytes +=
4129                 pre_bytes * ((temp_prebuffer_ns / nano_seconds_per_second) / pre_sec);
4130 
4131             prebuffer = prebuffer_ns / nano_seconds_per_second;
4132 
4133             // Set this to 0.0 in case our prebuffer buffers the entire video.
4134             bits_per_second = 0.0;
4135             do {
4136                 int64_t desc_bytes = desc_end.end_offset - desc_beg.start_offset;
4137                 int64_t desc_ns = desc_end.end_time_ns - desc_beg.start_time_ns;
4138                 double desc_sec = desc_ns / nano_seconds_per_second;
4139                 double calc_bits_per_second = (desc_bytes * 8) / desc_sec;
4140 
4141                 // Drop the bps by the percentage of bytes buffered.
4142                 double percent = (desc_bytes - prebuffer_bytes) / desc_bytes;
4143                 double mod_bits_per_second = calc_bits_per_second * percent;
4144 
4145                 if (prebuffer < desc_sec) {
4146                     double search_sec =
4147                         (double)(matroska->duration * matroska->time_scale) / nano_seconds_per_second;
4148 
4149                     // Add 1 so the bits per second should be a little bit greater than file
4150                     // datarate.
4151                     int64_t bps = (int64_t)(mod_bits_per_second) + 1;
4152                     const double min_buffer = 0.0;
4153                     double buffer = prebuffer;
4154                     double sec_to_download = 0.0;
4155 
4156                     int rv = buffer_size_after_time_downloaded(prebuffered_ns, search_sec, bps,
4157                                                                min_buffer, &buffer, &sec_to_download,
4158                                                                s, cues_start);
4159                     if (rv < 0) {
4160                         return -1;
4161                     } else if (rv == 0) {
4162                         bits_per_second = (double)(bps);
4163                         break;
4164                     }
4165                 }
4166 
4167                 desc_end = get_cue_desc(s, desc_end.end_time_ns, cues_start);
4168             } while (desc_end.start_time_ns != -1);
4169         }
4170         if (bandwidth < bits_per_second) bandwidth = bits_per_second;
4171     }
4172     return (int64_t)bandwidth;
4173 }
4174 
webm_dash_manifest_cues(AVFormatContext * s,int64_t init_range)4175 static int webm_dash_manifest_cues(AVFormatContext *s, int64_t init_range)
4176 {
4177     MatroskaDemuxContext *matroska = s->priv_data;
4178     EbmlList *seekhead_list = &matroska->seekhead;
4179     MatroskaSeekhead *seekhead = seekhead_list->elem;
4180     char *buf;
4181     int64_t cues_start = -1, cues_end = -1, before_pos, bandwidth;
4182     int i;
4183     int end = 0;
4184 
4185     // determine cues start and end positions
4186     for (i = 0; i < seekhead_list->nb_elem; i++)
4187         if (seekhead[i].id == MATROSKA_ID_CUES)
4188             break;
4189 
4190     if (i >= seekhead_list->nb_elem) return -1;
4191 
4192     before_pos = avio_tell(matroska->ctx->pb);
4193     cues_start = seekhead[i].pos + matroska->segment_start;
4194     if (avio_seek(matroska->ctx->pb, cues_start, SEEK_SET) == cues_start) {
4195         // cues_end is computed as cues_start + cues_length + length of the
4196         // Cues element ID (i.e. 4) + EBML length of the Cues element.
4197         // cues_end is inclusive and the above sum is reduced by 1.
4198         uint64_t cues_length, cues_id;
4199         int bytes_read;
4200         bytes_read = ebml_read_num   (matroska, matroska->ctx->pb, 4, &cues_id, 1);
4201         if (bytes_read < 0 || cues_id != (MATROSKA_ID_CUES & 0xfffffff))
4202             return bytes_read < 0 ? bytes_read : AVERROR_INVALIDDATA;
4203         bytes_read = ebml_read_length(matroska, matroska->ctx->pb, &cues_length);
4204         if (bytes_read < 0)
4205             return bytes_read;
4206         cues_end = cues_start + 4 + bytes_read + cues_length - 1;
4207     }
4208     avio_seek(matroska->ctx->pb, before_pos, SEEK_SET);
4209     if (cues_start == -1 || cues_end == -1) return -1;
4210 
4211     // parse the cues
4212     matroska_parse_cues(matroska);
4213 
4214     // cues start
4215     av_dict_set_int(&s->streams[0]->metadata, CUES_START, cues_start, 0);
4216 
4217     // cues end
4218     av_dict_set_int(&s->streams[0]->metadata, CUES_END, cues_end, 0);
4219 
4220     // if the file has cues at the start, fix up the init range so that
4221     // it does not include it
4222     if (cues_start <= init_range)
4223         av_dict_set_int(&s->streams[0]->metadata, INITIALIZATION_RANGE, cues_start - 1, 0);
4224 
4225     // bandwidth
4226     bandwidth = webm_dash_manifest_compute_bandwidth(s, cues_start);
4227     if (bandwidth < 0) return -1;
4228     av_dict_set_int(&s->streams[0]->metadata, BANDWIDTH, bandwidth, 0);
4229 
4230     // check if all clusters start with key frames
4231     av_dict_set_int(&s->streams[0]->metadata, CLUSTER_KEYFRAME, webm_clusters_start_with_keyframe(s), 0);
4232 
4233     // store cue point timestamps as a comma separated list for checking subsegment alignment in
4234     // the muxer. assumes that each timestamp cannot be more than 20 characters long.
4235     buf = av_malloc_array(s->streams[0]->nb_index_entries, 20);
4236     if (!buf) return -1;
4237     strcpy(buf, "");
4238     for (i = 0; i < s->streams[0]->nb_index_entries; i++) {
4239         int ret = snprintf(buf + end, 20,
4240                            "%" PRId64"%s", s->streams[0]->index_entries[i].timestamp,
4241                            i != s->streams[0]->nb_index_entries - 1 ? "," : "");
4242         if (ret <= 0 || (ret == 20 && i ==  s->streams[0]->nb_index_entries - 1)) {
4243             av_log(s, AV_LOG_ERROR, "timestamp too long.\n");
4244             av_free(buf);
4245             return AVERROR_INVALIDDATA;
4246         }
4247         end += ret;
4248     }
4249     av_dict_set(&s->streams[0]->metadata, CUE_TIMESTAMPS,
4250                 buf, AV_DICT_DONT_STRDUP_VAL);
4251 
4252     return 0;
4253 }
4254 
webm_dash_manifest_read_header(AVFormatContext * s)4255 static int webm_dash_manifest_read_header(AVFormatContext *s)
4256 {
4257     char *buf;
4258     int ret = matroska_read_header(s);
4259     int64_t init_range;
4260     MatroskaTrack *tracks;
4261     MatroskaDemuxContext *matroska = s->priv_data;
4262     if (ret) {
4263         av_log(s, AV_LOG_ERROR, "Failed to read file headers\n");
4264         return -1;
4265     }
4266     if (!matroska->tracks.nb_elem || !s->nb_streams) {
4267         av_log(s, AV_LOG_ERROR, "No track found\n");
4268         ret = AVERROR_INVALIDDATA;
4269         goto fail;
4270     }
4271 
4272     if (!matroska->is_live) {
4273         buf = av_asprintf("%g", matroska->duration);
4274         if (!buf) {
4275             ret = AVERROR(ENOMEM);
4276             goto fail;
4277         }
4278         av_dict_set(&s->streams[0]->metadata, DURATION,
4279                     buf, AV_DICT_DONT_STRDUP_VAL);
4280 
4281         // initialization range
4282         // 5 is the offset of Cluster ID.
4283         init_range = avio_tell(s->pb) - 5;
4284         av_dict_set_int(&s->streams[0]->metadata, INITIALIZATION_RANGE, init_range, 0);
4285     }
4286 
4287     // basename of the file
4288     buf = strrchr(s->url, '/');
4289     av_dict_set(&s->streams[0]->metadata, FILENAME, buf ? ++buf : s->url, 0);
4290 
4291     // track number
4292     tracks = matroska->tracks.elem;
4293     av_dict_set_int(&s->streams[0]->metadata, TRACK_NUMBER, tracks[0].num, 0);
4294 
4295     // parse the cues and populate Cue related fields
4296     if (!matroska->is_live) {
4297         ret = webm_dash_manifest_cues(s, init_range);
4298         if (ret < 0) {
4299             av_log(s, AV_LOG_ERROR, "Error parsing Cues\n");
4300             goto fail;
4301         }
4302     }
4303 
4304     // use the bandwidth from the command line if it was provided
4305     if (matroska->bandwidth > 0) {
4306         av_dict_set_int(&s->streams[0]->metadata, BANDWIDTH,
4307                         matroska->bandwidth, 0);
4308     }
4309     return 0;
4310 fail:
4311     matroska_read_close(s);
4312     return ret;
4313 }
4314 
webm_dash_manifest_read_packet(AVFormatContext * s,AVPacket * pkt)4315 static int webm_dash_manifest_read_packet(AVFormatContext *s, AVPacket *pkt)
4316 {
4317     return AVERROR_EOF;
4318 }
4319 
4320 #define OFFSET(x) offsetof(MatroskaDemuxContext, x)
4321 static const AVOption options[] = {
4322     { "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 },
4323     { "bandwidth", "bandwidth of this stream to be specified in the DASH manifest.", OFFSET(bandwidth), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
4324     { NULL },
4325 };
4326 
4327 static const AVClass webm_dash_class = {
4328     .class_name = "WebM DASH Manifest demuxer",
4329     .item_name  = av_default_item_name,
4330     .option     = options,
4331     .version    = LIBAVUTIL_VERSION_INT,
4332 };
4333 
4334 AVInputFormat ff_matroska_demuxer = {
4335     .name           = "matroska,webm",
4336     .long_name      = NULL_IF_CONFIG_SMALL("Matroska / WebM"),
4337     .extensions     = "mkv,mk3d,mka,mks,webm",
4338     .priv_data_size = sizeof(MatroskaDemuxContext),
4339     .read_probe     = matroska_probe,
4340     .read_header    = matroska_read_header,
4341     .read_packet    = matroska_read_packet,
4342     .read_close     = matroska_read_close,
4343     .read_seek      = matroska_read_seek,
4344     .mime_type      = "audio/webm,audio/x-matroska,video/webm,video/x-matroska"
4345 };
4346 
4347 AVInputFormat ff_webm_dash_manifest_demuxer = {
4348     .name           = "webm_dash_manifest",
4349     .long_name      = NULL_IF_CONFIG_SMALL("WebM DASH Manifest"),
4350     .priv_data_size = sizeof(MatroskaDemuxContext),
4351     .read_header    = webm_dash_manifest_read_header,
4352     .read_packet    = webm_dash_manifest_read_packet,
4353     .read_close     = matroska_read_close,
4354     .priv_class     = &webm_dash_class,
4355 };
4356