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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 #if CONFIG_LZO
1641     int olen;
1642 #endif
1643 
1644     if (pkt_size >= 10000000U)
1645         return AVERROR_INVALIDDATA;
1646 
1647     switch (encodings[0].compression.algo) {
1648     case MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP:
1649     {
1650         int header_size = encodings[0].compression.settings.size;
1651         uint8_t *header = encodings[0].compression.settings.data;
1652 
1653         if (header_size && !header) {
1654             av_log(NULL, AV_LOG_ERROR, "Compression size but no data in headerstrip\n");
1655             return -1;
1656         }
1657 
1658         if (!header_size)
1659             return 0;
1660 
1661         pkt_size = isize + header_size;
1662         pkt_data = av_malloc(pkt_size + AV_INPUT_BUFFER_PADDING_SIZE);
1663         if (!pkt_data)
1664             return AVERROR(ENOMEM);
1665 
1666         memcpy(pkt_data, header, header_size);
1667         memcpy(pkt_data + header_size, data, isize);
1668         break;
1669     }
1670 #if CONFIG_LZO
1671     case MATROSKA_TRACK_ENCODING_COMP_LZO:
1672         do {
1673             int insize = isize;
1674             olen       = pkt_size *= 3;
1675             newpktdata = av_realloc(pkt_data, pkt_size + AV_LZO_OUTPUT_PADDING
1676                                                        + AV_INPUT_BUFFER_PADDING_SIZE);
1677             if (!newpktdata) {
1678                 result = AVERROR(ENOMEM);
1679                 goto failed;
1680             }
1681             pkt_data = newpktdata;
1682             result   = av_lzo1x_decode(pkt_data, &olen, data, &insize);
1683         } while (result == AV_LZO_OUTPUT_FULL && pkt_size < 10000000);
1684         if (result) {
1685             result = AVERROR_INVALIDDATA;
1686             goto failed;
1687         }
1688         pkt_size -= olen;
1689         break;
1690 #endif
1691 #if CONFIG_ZLIB
1692     case MATROSKA_TRACK_ENCODING_COMP_ZLIB:
1693     {
1694         z_stream zstream = { 0 };
1695         if (inflateInit(&zstream) != Z_OK)
1696             return -1;
1697         zstream.next_in  = data;
1698         zstream.avail_in = isize;
1699         do {
1700             pkt_size  *= 3;
1701             newpktdata = av_realloc(pkt_data, pkt_size + AV_INPUT_BUFFER_PADDING_SIZE);
1702             if (!newpktdata) {
1703                 inflateEnd(&zstream);
1704                 result = AVERROR(ENOMEM);
1705                 goto failed;
1706             }
1707             pkt_data          = newpktdata;
1708             zstream.avail_out = pkt_size - zstream.total_out;
1709             zstream.next_out  = pkt_data + zstream.total_out;
1710             result = inflate(&zstream, Z_NO_FLUSH);
1711         } while (result == Z_OK && pkt_size < 10000000);
1712         pkt_size = zstream.total_out;
1713         inflateEnd(&zstream);
1714         if (result != Z_STREAM_END) {
1715             if (result == Z_MEM_ERROR)
1716                 result = AVERROR(ENOMEM);
1717             else
1718                 result = AVERROR_INVALIDDATA;
1719             goto failed;
1720         }
1721         break;
1722     }
1723 #endif
1724 #if CONFIG_BZLIB
1725     case MATROSKA_TRACK_ENCODING_COMP_BZLIB:
1726     {
1727         bz_stream bzstream = { 0 };
1728         if (BZ2_bzDecompressInit(&bzstream, 0, 0) != BZ_OK)
1729             return -1;
1730         bzstream.next_in  = data;
1731         bzstream.avail_in = isize;
1732         do {
1733             pkt_size  *= 3;
1734             newpktdata = av_realloc(pkt_data, pkt_size + AV_INPUT_BUFFER_PADDING_SIZE);
1735             if (!newpktdata) {
1736                 BZ2_bzDecompressEnd(&bzstream);
1737                 result = AVERROR(ENOMEM);
1738                 goto failed;
1739             }
1740             pkt_data           = newpktdata;
1741             bzstream.avail_out = pkt_size - bzstream.total_out_lo32;
1742             bzstream.next_out  = pkt_data + bzstream.total_out_lo32;
1743             result = BZ2_bzDecompress(&bzstream);
1744         } while (result == BZ_OK && pkt_size < 10000000);
1745         pkt_size = bzstream.total_out_lo32;
1746         BZ2_bzDecompressEnd(&bzstream);
1747         if (result != BZ_STREAM_END) {
1748             if (result == BZ_MEM_ERROR)
1749                 result = AVERROR(ENOMEM);
1750             else
1751                 result = AVERROR_INVALIDDATA;
1752             goto failed;
1753         }
1754         break;
1755     }
1756 #endif
1757     default:
1758         return AVERROR_INVALIDDATA;
1759     }
1760 
1761     memset(pkt_data + pkt_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
1762 
1763     *buf      = pkt_data;
1764     *buf_size = pkt_size;
1765     return 0;
1766 
1767 failed:
1768     av_free(pkt_data);
1769     return result;
1770 }
1771 
matroska_convert_tag(AVFormatContext * s,EbmlList * list,AVDictionary ** metadata,char * prefix)1772 static void matroska_convert_tag(AVFormatContext *s, EbmlList *list,
1773                                  AVDictionary **metadata, char *prefix)
1774 {
1775     MatroskaTag *tags = list->elem;
1776     char key[1024];
1777     int i;
1778 
1779     for (i = 0; i < list->nb_elem; i++) {
1780         const char *lang = tags[i].lang &&
1781                            strcmp(tags[i].lang, "und") ? tags[i].lang : NULL;
1782 
1783         if (!tags[i].name) {
1784             av_log(s, AV_LOG_WARNING, "Skipping invalid tag with no TagName.\n");
1785             continue;
1786         }
1787         if (prefix)
1788             snprintf(key, sizeof(key), "%s/%s", prefix, tags[i].name);
1789         else
1790             av_strlcpy(key, tags[i].name, sizeof(key));
1791         if (tags[i].def || !lang) {
1792             av_dict_set(metadata, key, tags[i].string, 0);
1793             if (tags[i].sub.nb_elem)
1794                 matroska_convert_tag(s, &tags[i].sub, metadata, key);
1795         }
1796         if (lang) {
1797             av_strlcat(key, "-", sizeof(key));
1798             av_strlcat(key, lang, sizeof(key));
1799             av_dict_set(metadata, key, tags[i].string, 0);
1800             if (tags[i].sub.nb_elem)
1801                 matroska_convert_tag(s, &tags[i].sub, metadata, key);
1802         }
1803     }
1804     ff_metadata_conv(metadata, NULL, ff_mkv_metadata_conv);
1805 }
1806 
matroska_convert_tags(AVFormatContext * s)1807 static void matroska_convert_tags(AVFormatContext *s)
1808 {
1809     MatroskaDemuxContext *matroska = s->priv_data;
1810     MatroskaTags *tags = matroska->tags.elem;
1811     int i, j;
1812 
1813     for (i = 0; i < matroska->tags.nb_elem; i++) {
1814         if (tags[i].target.attachuid) {
1815             MatroskaAttachment *attachment = matroska->attachments.elem;
1816             int found = 0;
1817             for (j = 0; j < matroska->attachments.nb_elem; j++) {
1818                 if (attachment[j].uid == tags[i].target.attachuid &&
1819                     attachment[j].stream) {
1820                     matroska_convert_tag(s, &tags[i].tag,
1821                                          &attachment[j].stream->metadata, NULL);
1822                     found = 1;
1823                 }
1824             }
1825             if (!found) {
1826                 av_log(s, AV_LOG_WARNING,
1827                        "The tags at index %d refer to a "
1828                        "non-existent attachment %"PRId64".\n",
1829                        i, tags[i].target.attachuid);
1830             }
1831         } else if (tags[i].target.chapteruid) {
1832             MatroskaChapter *chapter = matroska->chapters.elem;
1833             int found = 0;
1834             for (j = 0; j < matroska->chapters.nb_elem; j++) {
1835                 if (chapter[j].uid == tags[i].target.chapteruid &&
1836                     chapter[j].chapter) {
1837                     matroska_convert_tag(s, &tags[i].tag,
1838                                          &chapter[j].chapter->metadata, NULL);
1839                     found = 1;
1840                 }
1841             }
1842             if (!found) {
1843                 av_log(s, AV_LOG_WARNING,
1844                        "The tags at index %d refer to a non-existent chapter "
1845                        "%"PRId64".\n",
1846                        i, tags[i].target.chapteruid);
1847             }
1848         } else if (tags[i].target.trackuid) {
1849             MatroskaTrack *track = matroska->tracks.elem;
1850             int found = 0;
1851             for (j = 0; j < matroska->tracks.nb_elem; j++) {
1852                 if (track[j].uid == tags[i].target.trackuid &&
1853                     track[j].stream) {
1854                     matroska_convert_tag(s, &tags[i].tag,
1855                                          &track[j].stream->metadata, NULL);
1856                     found = 1;
1857                }
1858             }
1859             if (!found) {
1860                 av_log(s, AV_LOG_WARNING,
1861                        "The tags at index %d refer to a non-existent track "
1862                        "%"PRId64".\n",
1863                        i, tags[i].target.trackuid);
1864             }
1865         } else {
1866             matroska_convert_tag(s, &tags[i].tag, &s->metadata,
1867                                  tags[i].target.type);
1868         }
1869     }
1870 }
1871 
matroska_parse_seekhead_entry(MatroskaDemuxContext * matroska,int64_t pos)1872 static int matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska,
1873                                          int64_t pos)
1874 {
1875     uint32_t saved_id  = matroska->current_id;
1876     int64_t before_pos = avio_tell(matroska->ctx->pb);
1877     int ret = 0;
1878     int ret2;
1879 
1880     /* seek */
1881     if (avio_seek(matroska->ctx->pb, pos, SEEK_SET) == pos) {
1882         /* We don't want to lose our seekhead level, so we add
1883          * a dummy. This is a crude hack. */
1884         if (matroska->num_levels == EBML_MAX_DEPTH) {
1885             av_log(matroska->ctx, AV_LOG_INFO,
1886                    "Max EBML element depth (%d) reached, "
1887                    "cannot parse further.\n", EBML_MAX_DEPTH);
1888             ret = AVERROR_INVALIDDATA;
1889         } else {
1890             matroska->levels[matroska->num_levels] = (MatroskaLevel) { 0, EBML_UNKNOWN_LENGTH };
1891             matroska->num_levels++;
1892             matroska->current_id                   = 0;
1893 
1894             ret = ebml_parse(matroska, matroska_segment, matroska);
1895             if (ret == LEVEL_ENDED) {
1896                 /* This can only happen if the seek brought us beyond EOF. */
1897                 ret = AVERROR_EOF;
1898             }
1899         }
1900     }
1901     /* Seek back - notice that in all instances where this is used
1902      * it is safe to set the level to 1. */
1903     ret2 = matroska_reset_status(matroska, saved_id, before_pos);
1904     if (ret >= 0)
1905         ret = ret2;
1906 
1907     return ret;
1908 }
1909 
matroska_execute_seekhead(MatroskaDemuxContext * matroska)1910 static void matroska_execute_seekhead(MatroskaDemuxContext *matroska)
1911 {
1912     EbmlList *seekhead_list = &matroska->seekhead;
1913     int i;
1914 
1915     // we should not do any seeking in the streaming case
1916     if (!(matroska->ctx->pb->seekable & AVIO_SEEKABLE_NORMAL))
1917         return;
1918 
1919     for (i = 0; i < seekhead_list->nb_elem; i++) {
1920         MatroskaSeekhead *seekheads = seekhead_list->elem;
1921         uint32_t id = seekheads[i].id;
1922         int64_t pos = seekheads[i].pos + matroska->segment_start;
1923         MatroskaLevel1Element *elem;
1924 
1925         if (id != seekheads[i].id || pos < matroska->segment_start)
1926             continue;
1927 
1928         elem = matroska_find_level1_elem(matroska, id, pos);
1929         if (!elem || elem->parsed)
1930             continue;
1931 
1932         elem->pos = pos;
1933 
1934         // defer cues parsing until we actually need cue data.
1935         if (id == MATROSKA_ID_CUES)
1936             continue;
1937 
1938         if (matroska_parse_seekhead_entry(matroska, pos) < 0) {
1939             // mark index as broken
1940             matroska->cues_parsing_deferred = -1;
1941             break;
1942         }
1943 
1944         elem->parsed = 1;
1945     }
1946 }
1947 
matroska_add_index_entries(MatroskaDemuxContext * matroska)1948 static void matroska_add_index_entries(MatroskaDemuxContext *matroska)
1949 {
1950     EbmlList *index_list;
1951     MatroskaIndex *index;
1952     uint64_t index_scale = 1;
1953     int i, j;
1954 
1955     if (matroska->ctx->flags & AVFMT_FLAG_IGNIDX)
1956         return;
1957 
1958     index_list = &matroska->index;
1959     index      = index_list->elem;
1960     if (index_list->nb_elem < 2)
1961         return;
1962     if (index[1].time > 1E14 / matroska->time_scale) {
1963         av_log(matroska->ctx, AV_LOG_WARNING, "Dropping apparently-broken index.\n");
1964         return;
1965     }
1966     for (i = 0; i < index_list->nb_elem; i++) {
1967         EbmlList *pos_list    = &index[i].pos;
1968         MatroskaIndexPos *pos = pos_list->elem;
1969         for (j = 0; j < pos_list->nb_elem; j++) {
1970             MatroskaTrack *track = matroska_find_track_by_num(matroska,
1971                                                               pos[j].track);
1972             if (track && track->stream)
1973                 av_add_index_entry(track->stream,
1974                                    pos[j].pos + matroska->segment_start,
1975                                    index[i].time / index_scale, 0, 0,
1976                                    AVINDEX_KEYFRAME);
1977         }
1978     }
1979 }
1980 
matroska_parse_cues(MatroskaDemuxContext * matroska)1981 static void matroska_parse_cues(MatroskaDemuxContext *matroska) {
1982     int i;
1983 
1984     if (matroska->ctx->flags & AVFMT_FLAG_IGNIDX)
1985         return;
1986 
1987     for (i = 0; i < matroska->num_level1_elems; i++) {
1988         MatroskaLevel1Element *elem = &matroska->level1_elems[i];
1989         if (elem->id == MATROSKA_ID_CUES && !elem->parsed) {
1990             if (matroska_parse_seekhead_entry(matroska, elem->pos) < 0)
1991                 matroska->cues_parsing_deferred = -1;
1992             elem->parsed = 1;
1993             break;
1994         }
1995     }
1996 
1997     matroska_add_index_entries(matroska);
1998 }
1999 
matroska_aac_profile(char * codec_id)2000 static int matroska_aac_profile(char *codec_id)
2001 {
2002     static const char *const aac_profiles[] = { "MAIN", "LC", "SSR" };
2003     int profile;
2004 
2005     for (profile = 0; profile < FF_ARRAY_ELEMS(aac_profiles); profile++)
2006         if (strstr(codec_id, aac_profiles[profile]))
2007             break;
2008     return profile + 1;
2009 }
2010 
matroska_aac_sri(int samplerate)2011 static int matroska_aac_sri(int samplerate)
2012 {
2013     int sri;
2014 
2015     for (sri = 0; sri < FF_ARRAY_ELEMS(avpriv_mpeg4audio_sample_rates); sri++)
2016         if (avpriv_mpeg4audio_sample_rates[sri] == samplerate)
2017             break;
2018     return sri;
2019 }
2020 
matroska_metadata_creation_time(AVDictionary ** metadata,int64_t date_utc)2021 static void matroska_metadata_creation_time(AVDictionary **metadata, int64_t date_utc)
2022 {
2023     /* Convert to seconds and adjust by number of seconds between 2001-01-01 and Epoch */
2024     avpriv_dict_set_timestamp(metadata, "creation_time", date_utc / 1000 + 978307200000000LL);
2025 }
2026 
matroska_parse_flac(AVFormatContext * s,MatroskaTrack * track,int * offset)2027 static int matroska_parse_flac(AVFormatContext *s,
2028                                MatroskaTrack *track,
2029                                int *offset)
2030 {
2031     AVStream *st = track->stream;
2032     uint8_t *p = track->codec_priv.data;
2033     int size   = track->codec_priv.size;
2034 
2035     if (size < 8 + FLAC_STREAMINFO_SIZE || p[4] & 0x7f) {
2036         av_log(s, AV_LOG_WARNING, "Invalid FLAC private data\n");
2037         track->codec_priv.size = 0;
2038         return 0;
2039     }
2040     *offset = 8;
2041     track->codec_priv.size = 8 + FLAC_STREAMINFO_SIZE;
2042 
2043     p    += track->codec_priv.size;
2044     size -= track->codec_priv.size;
2045 
2046     /* parse the remaining metadata blocks if present */
2047     while (size >= 4) {
2048         int block_last, block_type, block_size;
2049 
2050         flac_parse_block_header(p, &block_last, &block_type, &block_size);
2051 
2052         p    += 4;
2053         size -= 4;
2054         if (block_size > size)
2055             return 0;
2056 
2057         /* check for the channel mask */
2058         if (block_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
2059             AVDictionary *dict = NULL;
2060             AVDictionaryEntry *chmask;
2061 
2062             ff_vorbis_comment(s, &dict, p, block_size, 0);
2063             chmask = av_dict_get(dict, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0);
2064             if (chmask) {
2065                 uint64_t mask = strtol(chmask->value, NULL, 0);
2066                 if (!mask || mask & ~0x3ffffULL) {
2067                     av_log(s, AV_LOG_WARNING,
2068                            "Invalid value of WAVEFORMATEXTENSIBLE_CHANNEL_MASK\n");
2069                 } else
2070                     st->codecpar->channel_layout = mask;
2071             }
2072             av_dict_free(&dict);
2073         }
2074 
2075         p    += block_size;
2076         size -= block_size;
2077     }
2078 
2079     return 0;
2080 }
2081 
mkv_field_order(MatroskaDemuxContext * matroska,int64_t field_order)2082 static int mkv_field_order(MatroskaDemuxContext *matroska, int64_t field_order)
2083 {
2084     int minor, micro, bttb = 0;
2085 
2086     /* workaround a bug in our Matroska muxer, introduced in version 57.36 alongside
2087      * this function, and fixed in 57.52 */
2088     if (matroska->muxingapp && sscanf(matroska->muxingapp, "Lavf57.%d.%d", &minor, &micro) == 2)
2089         bttb = (minor >= 36 && minor <= 51 && micro >= 100);
2090 
2091     switch (field_order) {
2092     case MATROSKA_VIDEO_FIELDORDER_PROGRESSIVE:
2093         return AV_FIELD_PROGRESSIVE;
2094     case MATROSKA_VIDEO_FIELDORDER_UNDETERMINED:
2095         return AV_FIELD_UNKNOWN;
2096     case MATROSKA_VIDEO_FIELDORDER_TT:
2097         return AV_FIELD_TT;
2098     case MATROSKA_VIDEO_FIELDORDER_BB:
2099         return AV_FIELD_BB;
2100     case MATROSKA_VIDEO_FIELDORDER_BT:
2101         return bttb ? AV_FIELD_TB : AV_FIELD_BT;
2102     case MATROSKA_VIDEO_FIELDORDER_TB:
2103         return bttb ? AV_FIELD_BT : AV_FIELD_TB;
2104     default:
2105         return AV_FIELD_UNKNOWN;
2106     }
2107 }
2108 
mkv_stereo_mode_display_mul(int stereo_mode,int * h_width,int * h_height)2109 static void mkv_stereo_mode_display_mul(int stereo_mode,
2110                                         int *h_width, int *h_height)
2111 {
2112     switch (stereo_mode) {
2113         case MATROSKA_VIDEO_STEREOMODE_TYPE_MONO:
2114         case MATROSKA_VIDEO_STEREOMODE_TYPE_CHECKERBOARD_RL:
2115         case MATROSKA_VIDEO_STEREOMODE_TYPE_CHECKERBOARD_LR:
2116         case MATROSKA_VIDEO_STEREOMODE_TYPE_BOTH_EYES_BLOCK_RL:
2117         case MATROSKA_VIDEO_STEREOMODE_TYPE_BOTH_EYES_BLOCK_LR:
2118             break;
2119         case MATROSKA_VIDEO_STEREOMODE_TYPE_RIGHT_LEFT:
2120         case MATROSKA_VIDEO_STEREOMODE_TYPE_LEFT_RIGHT:
2121         case MATROSKA_VIDEO_STEREOMODE_TYPE_COL_INTERLEAVED_RL:
2122         case MATROSKA_VIDEO_STEREOMODE_TYPE_COL_INTERLEAVED_LR:
2123             *h_width = 2;
2124             break;
2125         case MATROSKA_VIDEO_STEREOMODE_TYPE_BOTTOM_TOP:
2126         case MATROSKA_VIDEO_STEREOMODE_TYPE_TOP_BOTTOM:
2127         case MATROSKA_VIDEO_STEREOMODE_TYPE_ROW_INTERLEAVED_RL:
2128         case MATROSKA_VIDEO_STEREOMODE_TYPE_ROW_INTERLEAVED_LR:
2129             *h_height = 2;
2130             break;
2131     }
2132 }
2133 
mkv_parse_video_color(AVStream * st,const MatroskaTrack * track)2134 static int mkv_parse_video_color(AVStream *st, const MatroskaTrack *track) {
2135     const MatroskaTrackVideoColor *color = track->video.color.elem;
2136     const MatroskaMasteringMeta *mastering_meta;
2137     int has_mastering_primaries, has_mastering_luminance;
2138 
2139     if (!track->video.color.nb_elem)
2140         return 0;
2141 
2142     mastering_meta = &color->mastering_meta;
2143     // Mastering primaries are CIE 1931 coords, and must be > 0.
2144     has_mastering_primaries =
2145         mastering_meta->r_x > 0 && mastering_meta->r_y > 0 &&
2146         mastering_meta->g_x > 0 && mastering_meta->g_y > 0 &&
2147         mastering_meta->b_x > 0 && mastering_meta->b_y > 0 &&
2148         mastering_meta->white_x > 0 && mastering_meta->white_y > 0;
2149     has_mastering_luminance = mastering_meta->max_luminance >
2150                                   mastering_meta->min_luminance.el.f  &&
2151                               mastering_meta->min_luminance.el.f >= 0 &&
2152                               mastering_meta->min_luminance.count;
2153 
2154     if (color->matrix_coefficients != AVCOL_SPC_RESERVED)
2155         st->codecpar->color_space = color->matrix_coefficients;
2156     if (color->primaries != AVCOL_PRI_RESERVED &&
2157         color->primaries != AVCOL_PRI_RESERVED0)
2158         st->codecpar->color_primaries = color->primaries;
2159     if (color->transfer_characteristics != AVCOL_TRC_RESERVED &&
2160         color->transfer_characteristics != AVCOL_TRC_RESERVED0)
2161         st->codecpar->color_trc = color->transfer_characteristics;
2162     if (color->range != AVCOL_RANGE_UNSPECIFIED &&
2163         color->range <= AVCOL_RANGE_JPEG)
2164         st->codecpar->color_range = color->range;
2165     if (color->chroma_siting_horz != MATROSKA_COLOUR_CHROMASITINGHORZ_UNDETERMINED &&
2166         color->chroma_siting_vert != MATROSKA_COLOUR_CHROMASITINGVERT_UNDETERMINED &&
2167         color->chroma_siting_horz  < MATROSKA_COLOUR_CHROMASITINGHORZ_NB &&
2168         color->chroma_siting_vert  < MATROSKA_COLOUR_CHROMASITINGVERT_NB) {
2169         st->codecpar->chroma_location =
2170             avcodec_chroma_pos_to_enum((color->chroma_siting_horz - 1) << 7,
2171                                        (color->chroma_siting_vert - 1) << 7);
2172     }
2173     if (color->max_cll && color->max_fall) {
2174         size_t size = 0;
2175         int ret;
2176         AVContentLightMetadata *metadata = av_content_light_metadata_alloc(&size);
2177         if (!metadata)
2178             return AVERROR(ENOMEM);
2179         ret = av_stream_add_side_data(st, AV_PKT_DATA_CONTENT_LIGHT_LEVEL,
2180                                       (uint8_t *)metadata, size);
2181         if (ret < 0) {
2182             av_freep(&metadata);
2183             return ret;
2184         }
2185         metadata->MaxCLL  = color->max_cll;
2186         metadata->MaxFALL = color->max_fall;
2187     }
2188 
2189     if (has_mastering_primaries || has_mastering_luminance) {
2190         AVMasteringDisplayMetadata *metadata =
2191             (AVMasteringDisplayMetadata*) av_stream_new_side_data(
2192                 st, AV_PKT_DATA_MASTERING_DISPLAY_METADATA,
2193                 sizeof(AVMasteringDisplayMetadata));
2194         if (!metadata) {
2195             return AVERROR(ENOMEM);
2196         }
2197         memset(metadata, 0, sizeof(AVMasteringDisplayMetadata));
2198         if (has_mastering_primaries) {
2199             metadata->display_primaries[0][0] = av_d2q(mastering_meta->r_x, INT_MAX);
2200             metadata->display_primaries[0][1] = av_d2q(mastering_meta->r_y, INT_MAX);
2201             metadata->display_primaries[1][0] = av_d2q(mastering_meta->g_x, INT_MAX);
2202             metadata->display_primaries[1][1] = av_d2q(mastering_meta->g_y, INT_MAX);
2203             metadata->display_primaries[2][0] = av_d2q(mastering_meta->b_x, INT_MAX);
2204             metadata->display_primaries[2][1] = av_d2q(mastering_meta->b_y, INT_MAX);
2205             metadata->white_point[0] = av_d2q(mastering_meta->white_x, INT_MAX);
2206             metadata->white_point[1] = av_d2q(mastering_meta->white_y, INT_MAX);
2207             metadata->has_primaries = 1;
2208         }
2209         if (has_mastering_luminance) {
2210             metadata->max_luminance = av_d2q(mastering_meta->max_luminance, INT_MAX);
2211             metadata->min_luminance = av_d2q(mastering_meta->min_luminance.el.f, INT_MAX);
2212             metadata->has_luminance = 1;
2213         }
2214     }
2215     return 0;
2216 }
2217 
mkv_parse_video_projection(AVStream * st,const MatroskaTrack * track,void * logctx)2218 static int mkv_parse_video_projection(AVStream *st, const MatroskaTrack *track,
2219                                       void *logctx)
2220 {
2221     AVSphericalMapping *spherical;
2222     const MatroskaTrackVideoProjection *mkv_projection = &track->video.projection;
2223     const uint8_t *priv_data = mkv_projection->private.data;
2224     enum AVSphericalProjection projection;
2225     size_t spherical_size;
2226     uint32_t l = 0, t = 0, r = 0, b = 0;
2227     uint32_t padding = 0;
2228     int ret;
2229 
2230     if (mkv_projection->private.size && priv_data[0] != 0) {
2231         av_log(logctx, AV_LOG_WARNING, "Unknown spherical metadata\n");
2232         return 0;
2233     }
2234 
2235     switch (track->video.projection.type) {
2236     case MATROSKA_VIDEO_PROJECTION_TYPE_EQUIRECTANGULAR:
2237         if (track->video.projection.private.size == 20) {
2238             t = AV_RB32(priv_data +  4);
2239             b = AV_RB32(priv_data +  8);
2240             l = AV_RB32(priv_data + 12);
2241             r = AV_RB32(priv_data + 16);
2242 
2243             if (b >= UINT_MAX - t || r >= UINT_MAX - l) {
2244                 av_log(logctx, AV_LOG_ERROR,
2245                        "Invalid bounding rectangle coordinates "
2246                        "%"PRIu32",%"PRIu32",%"PRIu32",%"PRIu32"\n",
2247                        l, t, r, b);
2248                 return AVERROR_INVALIDDATA;
2249             }
2250         } else if (track->video.projection.private.size != 0) {
2251             av_log(logctx, AV_LOG_ERROR, "Unknown spherical metadata\n");
2252             return AVERROR_INVALIDDATA;
2253         }
2254 
2255         if (l || t || r || b)
2256             projection = AV_SPHERICAL_EQUIRECTANGULAR_TILE;
2257         else
2258             projection = AV_SPHERICAL_EQUIRECTANGULAR;
2259         break;
2260     case MATROSKA_VIDEO_PROJECTION_TYPE_CUBEMAP:
2261         if (track->video.projection.private.size < 4) {
2262             av_log(logctx, AV_LOG_ERROR, "Missing projection private properties\n");
2263             return AVERROR_INVALIDDATA;
2264         } else if (track->video.projection.private.size == 12) {
2265             uint32_t layout = AV_RB32(priv_data + 4);
2266             if (layout) {
2267                 av_log(logctx, AV_LOG_WARNING,
2268                        "Unknown spherical cubemap layout %"PRIu32"\n", layout);
2269                 return 0;
2270             }
2271             projection = AV_SPHERICAL_CUBEMAP;
2272             padding = AV_RB32(priv_data + 8);
2273         } else {
2274             av_log(logctx, AV_LOG_ERROR, "Unknown spherical metadata\n");
2275             return AVERROR_INVALIDDATA;
2276         }
2277         break;
2278     case MATROSKA_VIDEO_PROJECTION_TYPE_RECTANGULAR:
2279         /* No Spherical metadata */
2280         return 0;
2281     default:
2282         av_log(logctx, AV_LOG_WARNING,
2283                "Unknown spherical metadata type %"PRIu64"\n",
2284                track->video.projection.type);
2285         return 0;
2286     }
2287 
2288     spherical = av_spherical_alloc(&spherical_size);
2289     if (!spherical)
2290         return AVERROR(ENOMEM);
2291 
2292     spherical->projection = projection;
2293 
2294     spherical->yaw   = (int32_t) (track->video.projection.yaw   * (1 << 16));
2295     spherical->pitch = (int32_t) (track->video.projection.pitch * (1 << 16));
2296     spherical->roll  = (int32_t) (track->video.projection.roll  * (1 << 16));
2297 
2298     spherical->padding = padding;
2299 
2300     spherical->bound_left   = l;
2301     spherical->bound_top    = t;
2302     spherical->bound_right  = r;
2303     spherical->bound_bottom = b;
2304 
2305     ret = av_stream_add_side_data(st, AV_PKT_DATA_SPHERICAL, (uint8_t *)spherical,
2306                                   spherical_size);
2307     if (ret < 0) {
2308         av_freep(&spherical);
2309         return ret;
2310     }
2311 
2312     return 0;
2313 }
2314 
get_qt_codec(MatroskaTrack * track,uint32_t * fourcc,enum AVCodecID * codec_id)2315 static int get_qt_codec(MatroskaTrack *track, uint32_t *fourcc, enum AVCodecID *codec_id)
2316 {
2317     const AVCodecTag *codec_tags;
2318 
2319     codec_tags = track->type == MATROSKA_TRACK_TYPE_VIDEO ?
2320             ff_codec_movvideo_tags : ff_codec_movaudio_tags;
2321 
2322     /* Normalize noncompliant private data that starts with the fourcc
2323      * by expanding/shifting the data by 4 bytes and storing the data
2324      * size at the start. */
2325     if (ff_codec_get_id(codec_tags, AV_RL32(track->codec_priv.data))) {
2326         int ret = av_buffer_realloc(&track->codec_priv.buf,
2327                                     track->codec_priv.size + 4 + AV_INPUT_BUFFER_PADDING_SIZE);
2328         if (ret < 0)
2329             return ret;
2330 
2331         track->codec_priv.data = track->codec_priv.buf->data;
2332         memmove(track->codec_priv.data + 4, track->codec_priv.data, track->codec_priv.size);
2333         track->codec_priv.size += 4;
2334         AV_WB32(track->codec_priv.data, track->codec_priv.size);
2335     }
2336 
2337     *fourcc = AV_RL32(track->codec_priv.data + 4);
2338     *codec_id = ff_codec_get_id(codec_tags, *fourcc);
2339 
2340     return 0;
2341 }
2342 
matroska_parse_tracks(AVFormatContext * s)2343 static int matroska_parse_tracks(AVFormatContext *s)
2344 {
2345     MatroskaDemuxContext *matroska = s->priv_data;
2346     MatroskaTrack *tracks = matroska->tracks.elem;
2347     AVStream *st;
2348     int i, j, ret;
2349     int k;
2350 
2351     for (i = 0; i < matroska->tracks.nb_elem; i++) {
2352         MatroskaTrack *track = &tracks[i];
2353         enum AVCodecID codec_id = AV_CODEC_ID_NONE;
2354         EbmlList *encodings_list = &track->encodings;
2355         MatroskaTrackEncoding *encodings = encodings_list->elem;
2356         uint8_t *extradata = NULL;
2357         int extradata_size = 0;
2358         int extradata_offset = 0;
2359         uint32_t fourcc = 0;
2360         AVIOContext b;
2361         char* key_id_base64 = NULL;
2362         int bit_depth = -1;
2363 
2364         /* Apply some sanity checks. */
2365         if (track->type != MATROSKA_TRACK_TYPE_VIDEO &&
2366             track->type != MATROSKA_TRACK_TYPE_AUDIO &&
2367             track->type != MATROSKA_TRACK_TYPE_SUBTITLE &&
2368             track->type != MATROSKA_TRACK_TYPE_METADATA) {
2369             av_log(matroska->ctx, AV_LOG_INFO,
2370                    "Unknown or unsupported track type %"PRIu64"\n",
2371                    track->type);
2372             continue;
2373         }
2374         if (!track->codec_id)
2375             continue;
2376 
2377         if (   track->type == MATROSKA_TRACK_TYPE_AUDIO && track->codec_id[0] != 'A'
2378             || track->type == MATROSKA_TRACK_TYPE_VIDEO && track->codec_id[0] != 'V'
2379             || track->type == MATROSKA_TRACK_TYPE_SUBTITLE && track->codec_id[0] != 'D' && track->codec_id[0] != 'S'
2380             || track->type == MATROSKA_TRACK_TYPE_METADATA && track->codec_id[0] != 'D' && track->codec_id[0] != 'S'
2381         ) {
2382             av_log(matroska->ctx, AV_LOG_INFO, "Inconsistent track type\n");
2383             continue;
2384         }
2385 
2386         if (track->audio.samplerate < 0 || track->audio.samplerate > INT_MAX ||
2387             isnan(track->audio.samplerate)) {
2388             av_log(matroska->ctx, AV_LOG_WARNING,
2389                    "Invalid sample rate %f, defaulting to 8000 instead.\n",
2390                    track->audio.samplerate);
2391             track->audio.samplerate = 8000;
2392         }
2393 
2394         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
2395             if (!track->default_duration && track->video.frame_rate > 0) {
2396                 double default_duration = 1000000000 / track->video.frame_rate;
2397                 if (default_duration > UINT64_MAX || default_duration < 0) {
2398                     av_log(matroska->ctx, AV_LOG_WARNING,
2399                          "Invalid frame rate %e. Cannot calculate default duration.\n",
2400                          track->video.frame_rate);
2401                 } else {
2402                     track->default_duration = default_duration;
2403                 }
2404             }
2405             if (track->video.display_width == -1)
2406                 track->video.display_width = track->video.pixel_width;
2407             if (track->video.display_height == -1)
2408                 track->video.display_height = track->video.pixel_height;
2409             if (track->video.color_space.size == 4)
2410                 fourcc = AV_RL32(track->video.color_space.data);
2411         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
2412             if (!track->audio.out_samplerate)
2413                 track->audio.out_samplerate = track->audio.samplerate;
2414         }
2415         if (encodings_list->nb_elem > 1) {
2416             av_log(matroska->ctx, AV_LOG_ERROR,
2417                    "Multiple combined encodings not supported");
2418         } else if (encodings_list->nb_elem == 1) {
2419             if (encodings[0].type) {
2420                 if (encodings[0].encryption.key_id.size > 0) {
2421                     /* Save the encryption key id to be stored later as a
2422                        metadata tag. */
2423                     const int b64_size = AV_BASE64_SIZE(encodings[0].encryption.key_id.size);
2424                     key_id_base64 = av_malloc(b64_size);
2425                     if (key_id_base64 == NULL)
2426                         return AVERROR(ENOMEM);
2427 
2428                     av_base64_encode(key_id_base64, b64_size,
2429                                      encodings[0].encryption.key_id.data,
2430                                      encodings[0].encryption.key_id.size);
2431                 } else {
2432                     encodings[0].scope = 0;
2433                     av_log(matroska->ctx, AV_LOG_ERROR,
2434                            "Unsupported encoding type");
2435                 }
2436             } else if (
2437 #if CONFIG_ZLIB
2438                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_ZLIB  &&
2439 #endif
2440 #if CONFIG_BZLIB
2441                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_BZLIB &&
2442 #endif
2443 #if CONFIG_LZO
2444                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_LZO   &&
2445 #endif
2446                  encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP) {
2447                 encodings[0].scope = 0;
2448                 av_log(matroska->ctx, AV_LOG_ERROR,
2449                        "Unsupported encoding type");
2450             } else if (track->codec_priv.size && encodings[0].scope & 2) {
2451                 uint8_t *codec_priv = track->codec_priv.data;
2452                 int ret = matroska_decode_buffer(&track->codec_priv.data,
2453                                                  &track->codec_priv.size,
2454                                                  track);
2455                 if (ret < 0) {
2456                     track->codec_priv.data = NULL;
2457                     track->codec_priv.size = 0;
2458                     av_log(matroska->ctx, AV_LOG_ERROR,
2459                            "Failed to decode codec private data\n");
2460                 }
2461 
2462                 if (codec_priv != track->codec_priv.data) {
2463                     av_buffer_unref(&track->codec_priv.buf);
2464                     if (track->codec_priv.data) {
2465                         track->codec_priv.buf = av_buffer_create(track->codec_priv.data,
2466                                                                  track->codec_priv.size + AV_INPUT_BUFFER_PADDING_SIZE,
2467                                                                  NULL, NULL, 0);
2468                         if (!track->codec_priv.buf) {
2469                             av_freep(&track->codec_priv.data);
2470                             track->codec_priv.size = 0;
2471                             return AVERROR(ENOMEM);
2472                         }
2473                     }
2474                 }
2475             }
2476         }
2477         track->needs_decoding = encodings && !encodings[0].type &&
2478                                 encodings[0].scope & 1          &&
2479                                 (encodings[0].compression.algo !=
2480                                    MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP ||
2481                                  encodings[0].compression.settings.size);
2482 
2483         for (j = 0; ff_mkv_codec_tags[j].id != AV_CODEC_ID_NONE; j++) {
2484             if (av_strstart(track->codec_id, ff_mkv_codec_tags[j].str, NULL)) {
2485                 codec_id = ff_mkv_codec_tags[j].id;
2486                 break;
2487             }
2488         }
2489 
2490         st = track->stream = avformat_new_stream(s, NULL);
2491         if (!st) {
2492             av_free(key_id_base64);
2493             return AVERROR(ENOMEM);
2494         }
2495 
2496         if (key_id_base64) {
2497             /* export encryption key id as base64 metadata tag */
2498             av_dict_set(&st->metadata, "enc_key_id", key_id_base64,
2499                         AV_DICT_DONT_STRDUP_VAL);
2500         }
2501 
2502         if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC") &&
2503              track->codec_priv.size >= 40               &&
2504             track->codec_priv.data) {
2505             track->ms_compat    = 1;
2506             bit_depth           = AV_RL16(track->codec_priv.data + 14);
2507             fourcc              = AV_RL32(track->codec_priv.data + 16);
2508             codec_id            = ff_codec_get_id(ff_codec_bmp_tags,
2509                                                   fourcc);
2510             if (!codec_id)
2511                 codec_id        = ff_codec_get_id(ff_codec_movvideo_tags,
2512                                                   fourcc);
2513             extradata_offset    = 40;
2514         } else if (!strcmp(track->codec_id, "A_MS/ACM") &&
2515                    track->codec_priv.size >= 14         &&
2516                    track->codec_priv.data) {
2517             int ret;
2518             ffio_init_context(&b, track->codec_priv.data,
2519                               track->codec_priv.size,
2520                               0, NULL, NULL, NULL, NULL);
2521             ret = ff_get_wav_header(s, &b, st->codecpar, track->codec_priv.size, 0);
2522             if (ret < 0)
2523                 return ret;
2524             codec_id         = st->codecpar->codec_id;
2525             fourcc           = st->codecpar->codec_tag;
2526             extradata_offset = FFMIN(track->codec_priv.size, 18);
2527         } else if (!strcmp(track->codec_id, "A_QUICKTIME")
2528                    /* Normally 36, but allow noncompliant private data */
2529                    && (track->codec_priv.size >= 32)
2530                    && (track->codec_priv.data)) {
2531             uint16_t sample_size;
2532             int ret = get_qt_codec(track, &fourcc, &codec_id);
2533             if (ret < 0)
2534                 return ret;
2535             sample_size = AV_RB16(track->codec_priv.data + 26);
2536             if (fourcc == 0) {
2537                 if (sample_size == 8) {
2538                     fourcc = MKTAG('r','a','w',' ');
2539                     codec_id = ff_codec_get_id(ff_codec_movaudio_tags, fourcc);
2540                 } else if (sample_size == 16) {
2541                     fourcc = MKTAG('t','w','o','s');
2542                     codec_id = ff_codec_get_id(ff_codec_movaudio_tags, fourcc);
2543                 }
2544             }
2545             if ((fourcc == MKTAG('t','w','o','s') ||
2546                     fourcc == MKTAG('s','o','w','t')) &&
2547                     sample_size == 8)
2548                 codec_id = AV_CODEC_ID_PCM_S8;
2549         } else if (!strcmp(track->codec_id, "V_QUICKTIME") &&
2550                    (track->codec_priv.size >= 21)          &&
2551                    (track->codec_priv.data)) {
2552             int ret = get_qt_codec(track, &fourcc, &codec_id);
2553             if (ret < 0)
2554                 return ret;
2555             if (codec_id == AV_CODEC_ID_NONE && AV_RL32(track->codec_priv.data+4) == AV_RL32("SMI ")) {
2556                 fourcc = MKTAG('S','V','Q','3');
2557                 codec_id = ff_codec_get_id(ff_codec_movvideo_tags, fourcc);
2558             }
2559             if (codec_id == AV_CODEC_ID_NONE)
2560                 av_log(matroska->ctx, AV_LOG_ERROR,
2561                        "mov FourCC not found %s.\n", av_fourcc2str(fourcc));
2562             if (track->codec_priv.size >= 86) {
2563                 bit_depth = AV_RB16(track->codec_priv.data + 82);
2564                 ffio_init_context(&b, track->codec_priv.data,
2565                                   track->codec_priv.size,
2566                                   0, NULL, NULL, NULL, NULL);
2567                 if (ff_get_qtpalette(codec_id, &b, track->palette)) {
2568                     bit_depth &= 0x1F;
2569                     track->has_palette = 1;
2570                 }
2571             }
2572         } else if (codec_id == AV_CODEC_ID_PCM_S16BE) {
2573             switch (track->audio.bitdepth) {
2574             case  8:
2575                 codec_id = AV_CODEC_ID_PCM_U8;
2576                 break;
2577             case 24:
2578                 codec_id = AV_CODEC_ID_PCM_S24BE;
2579                 break;
2580             case 32:
2581                 codec_id = AV_CODEC_ID_PCM_S32BE;
2582                 break;
2583             }
2584         } else if (codec_id == AV_CODEC_ID_PCM_S16LE) {
2585             switch (track->audio.bitdepth) {
2586             case  8:
2587                 codec_id = AV_CODEC_ID_PCM_U8;
2588                 break;
2589             case 24:
2590                 codec_id = AV_CODEC_ID_PCM_S24LE;
2591                 break;
2592             case 32:
2593                 codec_id = AV_CODEC_ID_PCM_S32LE;
2594                 break;
2595             }
2596         } else if (codec_id == AV_CODEC_ID_PCM_F32LE &&
2597                    track->audio.bitdepth == 64) {
2598             codec_id = AV_CODEC_ID_PCM_F64LE;
2599         } else if (codec_id == AV_CODEC_ID_AAC && !track->codec_priv.size) {
2600             int profile = matroska_aac_profile(track->codec_id);
2601             int sri     = matroska_aac_sri(track->audio.samplerate);
2602             extradata   = av_mallocz(5 + AV_INPUT_BUFFER_PADDING_SIZE);
2603             if (!extradata)
2604                 return AVERROR(ENOMEM);
2605             extradata[0] = (profile << 3) | ((sri & 0x0E) >> 1);
2606             extradata[1] = ((sri & 0x01) << 7) | (track->audio.channels << 3);
2607             if (strstr(track->codec_id, "SBR")) {
2608                 sri            = matroska_aac_sri(track->audio.out_samplerate);
2609                 extradata[2]   = 0x56;
2610                 extradata[3]   = 0xE5;
2611                 extradata[4]   = 0x80 | (sri << 3);
2612                 extradata_size = 5;
2613             } else
2614                 extradata_size = 2;
2615         } else if (codec_id == AV_CODEC_ID_ALAC && track->codec_priv.size && track->codec_priv.size < INT_MAX - 12 - AV_INPUT_BUFFER_PADDING_SIZE) {
2616             /* Only ALAC's magic cookie is stored in Matroska's track headers.
2617              * Create the "atom size", "tag", and "tag version" fields the
2618              * decoder expects manually. */
2619             extradata_size = 12 + track->codec_priv.size;
2620             extradata      = av_mallocz(extradata_size +
2621                                         AV_INPUT_BUFFER_PADDING_SIZE);
2622             if (!extradata)
2623                 return AVERROR(ENOMEM);
2624             AV_WB32(extradata, extradata_size);
2625             memcpy(&extradata[4], "alac", 4);
2626             AV_WB32(&extradata[8], 0);
2627             memcpy(&extradata[12], track->codec_priv.data,
2628                    track->codec_priv.size);
2629         } else if (codec_id == AV_CODEC_ID_TTA) {
2630             uint8_t *ptr;
2631             if (track->audio.channels > UINT16_MAX ||
2632                 track->audio.bitdepth > UINT16_MAX) {
2633                 av_log(matroska->ctx, AV_LOG_WARNING,
2634                        "Too large audio channel number %"PRIu64
2635                        " or bitdepth %"PRIu64". Skipping track.\n",
2636                        track->audio.channels, track->audio.bitdepth);
2637                 if (matroska->ctx->error_recognition & AV_EF_EXPLODE)
2638                     return AVERROR_INVALIDDATA;
2639                 else
2640                     continue;
2641             }
2642             if (track->audio.out_samplerate < 0 || track->audio.out_samplerate > INT_MAX)
2643                 return AVERROR_INVALIDDATA;
2644             extradata_size = 22;
2645             extradata      = av_mallocz(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
2646             if (!extradata)
2647                 return AVERROR(ENOMEM);
2648             ptr = extradata;
2649             bytestream_put_be32(&ptr, AV_RB32("TTA1"));
2650             bytestream_put_le16(&ptr, 1);
2651             bytestream_put_le16(&ptr, track->audio.channels);
2652             bytestream_put_le16(&ptr, track->audio.bitdepth);
2653             bytestream_put_le32(&ptr, track->audio.out_samplerate);
2654             bytestream_put_le32(&ptr, av_rescale(matroska->duration * matroska->time_scale,
2655                                                  track->audio.out_samplerate,
2656                                                  AV_TIME_BASE * 1000));
2657         } else if (codec_id == AV_CODEC_ID_RV10 ||
2658                    codec_id == AV_CODEC_ID_RV20 ||
2659                    codec_id == AV_CODEC_ID_RV30 ||
2660                    codec_id == AV_CODEC_ID_RV40) {
2661             extradata_offset = 26;
2662         } else if (codec_id == AV_CODEC_ID_RA_144) {
2663             track->audio.out_samplerate = 8000;
2664             track->audio.channels       = 1;
2665         } else if ((codec_id == AV_CODEC_ID_RA_288 ||
2666                     codec_id == AV_CODEC_ID_COOK   ||
2667                     codec_id == AV_CODEC_ID_ATRAC3 ||
2668                     codec_id == AV_CODEC_ID_SIPR)
2669                       && track->codec_priv.data) {
2670             int flavor;
2671 
2672             ffio_init_context(&b, track->codec_priv.data,
2673                               track->codec_priv.size,
2674                               0, NULL, NULL, NULL, NULL);
2675             avio_skip(&b, 22);
2676             flavor                       = avio_rb16(&b);
2677             track->audio.coded_framesize = avio_rb32(&b);
2678             avio_skip(&b, 12);
2679             track->audio.sub_packet_h    = avio_rb16(&b);
2680             track->audio.frame_size      = avio_rb16(&b);
2681             track->audio.sub_packet_size = avio_rb16(&b);
2682             if (track->audio.coded_framesize <= 0 ||
2683                 track->audio.sub_packet_h    <= 0 ||
2684                 track->audio.frame_size      <= 0)
2685                 return AVERROR_INVALIDDATA;
2686 
2687             if (codec_id == AV_CODEC_ID_RA_288) {
2688                 if (track->audio.sub_packet_h & 1 || 2 * track->audio.frame_size
2689                     != (int64_t)track->audio.sub_packet_h * track->audio.coded_framesize)
2690                     return AVERROR_INVALIDDATA;
2691                 st->codecpar->block_align = track->audio.coded_framesize;
2692                 track->codec_priv.size = 0;
2693             } else {
2694                 if (codec_id == AV_CODEC_ID_SIPR) {
2695                     static const int sipr_bit_rate[4] = { 6504, 8496, 5000, 16000 };
2696                     if (flavor > 3)
2697                         return AVERROR_INVALIDDATA;
2698                     track->audio.sub_packet_size = ff_sipr_subpk_size[flavor];
2699                     st->codecpar->bit_rate          = sipr_bit_rate[flavor];
2700                 } else if (track->audio.sub_packet_size <= 0 ||
2701                            track->audio.frame_size % track->audio.sub_packet_size)
2702                     return AVERROR_INVALIDDATA;
2703                 st->codecpar->block_align = track->audio.sub_packet_size;
2704                 extradata_offset       = 78;
2705             }
2706             track->audio.buf = av_malloc_array(track->audio.sub_packet_h,
2707                                                track->audio.frame_size);
2708             if (!track->audio.buf)
2709                 return AVERROR(ENOMEM);
2710         } else if (codec_id == AV_CODEC_ID_FLAC && track->codec_priv.size) {
2711             ret = matroska_parse_flac(s, track, &extradata_offset);
2712             if (ret < 0)
2713                 return ret;
2714         } else if (codec_id == AV_CODEC_ID_WAVPACK && track->codec_priv.size < 2) {
2715             av_log(matroska->ctx, AV_LOG_INFO, "Assuming WavPack version 4.10 "
2716                    "in absence of valid CodecPrivate.\n");
2717             extradata_size = 2;
2718             extradata = av_mallocz(2 + AV_INPUT_BUFFER_PADDING_SIZE);
2719             if (!extradata)
2720                 return AVERROR(ENOMEM);
2721             AV_WL16(extradata, 0x410);
2722         } else if (codec_id == AV_CODEC_ID_PRORES && track->codec_priv.size == 4) {
2723             fourcc = AV_RL32(track->codec_priv.data);
2724         } else if (codec_id == AV_CODEC_ID_VP9 && track->codec_priv.size) {
2725             /* we don't need any value stored in CodecPrivate.
2726                make sure that it's not exported as extradata. */
2727             track->codec_priv.size = 0;
2728         } else if (codec_id == AV_CODEC_ID_AV1 && track->codec_priv.size) {
2729             /* For now, propagate only the OBUs, if any. Once libavcodec is
2730                updated to handle isobmff style extradata this can be removed. */
2731             extradata_offset = 4;
2732         }
2733         track->codec_priv.size -= extradata_offset;
2734 
2735         if (codec_id == AV_CODEC_ID_NONE)
2736             av_log(matroska->ctx, AV_LOG_INFO,
2737                    "Unknown/unsupported AVCodecID %s.\n", track->codec_id);
2738 
2739         if (track->time_scale < 0.01) {
2740             av_log(matroska->ctx, AV_LOG_WARNING,
2741                    "Track TimestampScale too small %f, assuming 1.0.\n",
2742                    track->time_scale);
2743             track->time_scale = 1.0;
2744         }
2745         avpriv_set_pts_info(st, 64, matroska->time_scale * track->time_scale,
2746                             1000 * 1000 * 1000);    /* 64 bit pts in ns */
2747 
2748         /* convert the delay from ns to the track timebase */
2749         track->codec_delay_in_track_tb = av_rescale_q(track->codec_delay,
2750                                           (AVRational){ 1, 1000000000 },
2751                                           st->time_base);
2752 
2753         st->codecpar->codec_id = codec_id;
2754 
2755         if (strcmp(track->language, "und"))
2756             av_dict_set(&st->metadata, "language", track->language, 0);
2757         av_dict_set(&st->metadata, "title", track->name, 0);
2758 
2759         if (track->flag_default)
2760             st->disposition |= AV_DISPOSITION_DEFAULT;
2761         if (track->flag_forced)
2762             st->disposition |= AV_DISPOSITION_FORCED;
2763         if (track->flag_comment)
2764             st->disposition |= AV_DISPOSITION_COMMENT;
2765         if (track->flag_hearingimpaired)
2766             st->disposition |= AV_DISPOSITION_HEARING_IMPAIRED;
2767         if (track->flag_visualimpaired)
2768             st->disposition |= AV_DISPOSITION_VISUAL_IMPAIRED;
2769         if (track->flag_original.count > 0)
2770             st->disposition |= track->flag_original.el.u ? AV_DISPOSITION_ORIGINAL
2771                                                          : AV_DISPOSITION_DUB;
2772 
2773         if (!st->codecpar->extradata) {
2774             if (extradata) {
2775                 st->codecpar->extradata      = extradata;
2776                 st->codecpar->extradata_size = extradata_size;
2777             } else if (track->codec_priv.data && track->codec_priv.size > 0) {
2778                 if (ff_alloc_extradata(st->codecpar, track->codec_priv.size))
2779                     return AVERROR(ENOMEM);
2780                 memcpy(st->codecpar->extradata,
2781                        track->codec_priv.data + extradata_offset,
2782                        track->codec_priv.size);
2783             }
2784         }
2785 
2786         if (track->type == MATROSKA_TRACK_TYPE_VIDEO) {
2787             MatroskaTrackPlane *planes = track->operation.combine_planes.elem;
2788             int display_width_mul  = 1;
2789             int display_height_mul = 1;
2790 
2791             st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
2792             st->codecpar->codec_tag  = fourcc;
2793             if (bit_depth >= 0)
2794                 st->codecpar->bits_per_coded_sample = bit_depth;
2795             st->codecpar->width      = track->video.pixel_width;
2796             st->codecpar->height     = track->video.pixel_height;
2797 
2798             if (track->video.interlaced == MATROSKA_VIDEO_INTERLACE_FLAG_INTERLACED)
2799                 st->codecpar->field_order = mkv_field_order(matroska, track->video.field_order);
2800             else if (track->video.interlaced == MATROSKA_VIDEO_INTERLACE_FLAG_PROGRESSIVE)
2801                 st->codecpar->field_order = AV_FIELD_PROGRESSIVE;
2802 
2803             if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB)
2804                 mkv_stereo_mode_display_mul(track->video.stereo_mode, &display_width_mul, &display_height_mul);
2805 
2806             if (track->video.display_unit < MATROSKA_VIDEO_DISPLAYUNIT_UNKNOWN) {
2807                 av_reduce(&st->sample_aspect_ratio.num,
2808                           &st->sample_aspect_ratio.den,
2809                           st->codecpar->height * track->video.display_width  * display_width_mul,
2810                           st->codecpar->width  * track->video.display_height * display_height_mul,
2811                           255);
2812             }
2813             if (st->codecpar->codec_id != AV_CODEC_ID_HEVC)
2814                 st->need_parsing = AVSTREAM_PARSE_HEADERS;
2815 
2816             if (track->default_duration) {
2817                 int div = track->default_duration <= INT64_MAX ? 1 : 2;
2818                 av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
2819                           1000000000 / div, track->default_duration / div, 30000);
2820 #if FF_API_R_FRAME_RATE
2821                 if (   st->avg_frame_rate.num < st->avg_frame_rate.den * 1000LL
2822                     && st->avg_frame_rate.num > st->avg_frame_rate.den * 5LL)
2823                     st->r_frame_rate = st->avg_frame_rate;
2824 #endif
2825             }
2826 
2827             /* export stereo mode flag as metadata tag */
2828             if (track->video.stereo_mode && track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB)
2829                 av_dict_set(&st->metadata, "stereo_mode", ff_matroska_video_stereo_mode[track->video.stereo_mode], 0);
2830 
2831             /* export alpha mode flag as metadata tag  */
2832             if (track->video.alpha_mode)
2833                 av_dict_set(&st->metadata, "alpha_mode", "1", 0);
2834 
2835             /* if we have virtual track, mark the real tracks */
2836             for (j=0; j < track->operation.combine_planes.nb_elem; j++) {
2837                 char buf[32];
2838                 if (planes[j].type >= MATROSKA_VIDEO_STEREO_PLANE_COUNT)
2839                     continue;
2840                 snprintf(buf, sizeof(buf), "%s_%d",
2841                          ff_matroska_video_stereo_plane[planes[j].type], i);
2842                 for (k=0; k < matroska->tracks.nb_elem; k++)
2843                     if (planes[j].uid == tracks[k].uid && tracks[k].stream) {
2844                         av_dict_set(&tracks[k].stream->metadata,
2845                                     "stereo_mode", buf, 0);
2846                         break;
2847                     }
2848             }
2849             // add stream level stereo3d side data if it is a supported format
2850             if (track->video.stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB &&
2851                 track->video.stereo_mode != 10 && track->video.stereo_mode != 12) {
2852                 int ret = ff_mkv_stereo3d_conv(st, track->video.stereo_mode);
2853                 if (ret < 0)
2854                     return ret;
2855             }
2856 
2857             ret = mkv_parse_video_color(st, track);
2858             if (ret < 0)
2859                 return ret;
2860             ret = mkv_parse_video_projection(st, track, matroska->ctx);
2861             if (ret < 0)
2862                 return ret;
2863         } else if (track->type == MATROSKA_TRACK_TYPE_AUDIO) {
2864             st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
2865             st->codecpar->codec_tag   = fourcc;
2866             st->codecpar->sample_rate = track->audio.out_samplerate;
2867             st->codecpar->channels    = track->audio.channels;
2868             if (!st->codecpar->bits_per_coded_sample)
2869                 st->codecpar->bits_per_coded_sample = track->audio.bitdepth;
2870             if (st->codecpar->codec_id == AV_CODEC_ID_MP3 ||
2871                 st->codecpar->codec_id == AV_CODEC_ID_MLP ||
2872                 st->codecpar->codec_id == AV_CODEC_ID_TRUEHD)
2873                 st->need_parsing = AVSTREAM_PARSE_FULL;
2874             else if (st->codecpar->codec_id != AV_CODEC_ID_AAC)
2875                 st->need_parsing = AVSTREAM_PARSE_HEADERS;
2876             if (track->codec_delay > 0) {
2877                 st->codecpar->initial_padding = av_rescale_q(track->codec_delay,
2878                                                              (AVRational){1, 1000000000},
2879                                                              (AVRational){1, st->codecpar->codec_id == AV_CODEC_ID_OPUS ?
2880                                                                              48000 : st->codecpar->sample_rate});
2881             }
2882             if (track->seek_preroll > 0) {
2883                 st->codecpar->seek_preroll = av_rescale_q(track->seek_preroll,
2884                                                           (AVRational){1, 1000000000},
2885                                                           (AVRational){1, st->codecpar->sample_rate});
2886             }
2887         } else if (codec_id == AV_CODEC_ID_WEBVTT) {
2888             st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
2889 
2890             if (!strcmp(track->codec_id, "D_WEBVTT/CAPTIONS")) {
2891                 st->disposition |= AV_DISPOSITION_CAPTIONS;
2892             } else if (!strcmp(track->codec_id, "D_WEBVTT/DESCRIPTIONS")) {
2893                 st->disposition |= AV_DISPOSITION_DESCRIPTIONS;
2894             } else if (!strcmp(track->codec_id, "D_WEBVTT/METADATA")) {
2895                 st->disposition |= AV_DISPOSITION_METADATA;
2896             }
2897         } else if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE) {
2898             st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
2899 
2900             if (track->flag_textdescriptions)
2901                 st->disposition |= AV_DISPOSITION_DESCRIPTIONS;
2902         }
2903     }
2904 
2905     return 0;
2906 }
2907 
matroska_read_header(AVFormatContext * s)2908 static int matroska_read_header(AVFormatContext *s)
2909 {
2910     MatroskaDemuxContext *matroska = s->priv_data;
2911     EbmlList *attachments_list = &matroska->attachments;
2912     EbmlList *chapters_list    = &matroska->chapters;
2913     MatroskaAttachment *attachments;
2914     MatroskaChapter *chapters;
2915     uint64_t max_start = 0;
2916     int64_t pos;
2917     Ebml ebml = { 0 };
2918     int i, j, res;
2919 
2920     matroska->ctx = s;
2921     matroska->cues_parsing_deferred = 1;
2922 
2923     /* First read the EBML header. */
2924     if (ebml_parse(matroska, ebml_syntax, &ebml) || !ebml.doctype) {
2925         av_log(matroska->ctx, AV_LOG_ERROR, "EBML header parsing failed\n");
2926         ebml_free(ebml_syntax, &ebml);
2927         return AVERROR_INVALIDDATA;
2928     }
2929     if (ebml.version         > EBML_VERSION      ||
2930         ebml.max_size        > sizeof(uint64_t)  ||
2931         ebml.id_length       > sizeof(uint32_t)  ||
2932         ebml.doctype_version > 3) {
2933         avpriv_report_missing_feature(matroska->ctx,
2934                                       "EBML version %"PRIu64", doctype %s, doc version %"PRIu64,
2935                                       ebml.version, ebml.doctype, ebml.doctype_version);
2936         ebml_free(ebml_syntax, &ebml);
2937         return AVERROR_PATCHWELCOME;
2938     } else if (ebml.doctype_version == 3) {
2939         av_log(matroska->ctx, AV_LOG_WARNING,
2940                "EBML header using unsupported features\n"
2941                "(EBML version %"PRIu64", doctype %s, doc version %"PRIu64")\n",
2942                ebml.version, ebml.doctype, ebml.doctype_version);
2943     }
2944     for (i = 0; i < FF_ARRAY_ELEMS(matroska_doctypes); i++)
2945         if (!strcmp(ebml.doctype, matroska_doctypes[i]))
2946             break;
2947     if (i >= FF_ARRAY_ELEMS(matroska_doctypes)) {
2948         av_log(s, AV_LOG_WARNING, "Unknown EBML doctype '%s'\n", ebml.doctype);
2949         if (matroska->ctx->error_recognition & AV_EF_EXPLODE) {
2950             ebml_free(ebml_syntax, &ebml);
2951             return AVERROR_INVALIDDATA;
2952         }
2953     }
2954     ebml_free(ebml_syntax, &ebml);
2955 
2956     matroska->pkt = av_packet_alloc();
2957     if (!matroska->pkt)
2958         return AVERROR(ENOMEM);
2959 
2960     /* The next thing is a segment. */
2961     pos = avio_tell(matroska->ctx->pb);
2962     res = ebml_parse(matroska, matroska_segments, matroska);
2963     // Try resyncing until we find an EBML_STOP type element.
2964     while (res != 1) {
2965         res = matroska_resync(matroska, pos);
2966         if (res < 0)
2967             goto fail;
2968         pos = avio_tell(matroska->ctx->pb);
2969         res = ebml_parse(matroska, matroska_segment, matroska);
2970         if (res == AVERROR(EIO)) // EOF is translated to EIO, this exists the loop on EOF
2971             goto fail;
2972     }
2973     /* Set data_offset as it might be needed later by seek_frame_generic. */
2974     if (matroska->current_id == MATROSKA_ID_CLUSTER)
2975         s->internal->data_offset = avio_tell(matroska->ctx->pb) - 4;
2976     matroska_execute_seekhead(matroska);
2977 
2978     if (!matroska->time_scale)
2979         matroska->time_scale = 1000000;
2980     if (matroska->duration)
2981         matroska->ctx->duration = matroska->duration * matroska->time_scale *
2982                                   1000 / AV_TIME_BASE;
2983     av_dict_set(&s->metadata, "title", matroska->title, 0);
2984     av_dict_set(&s->metadata, "encoder", matroska->muxingapp, 0);
2985 
2986     if (matroska->date_utc.size == 8)
2987         matroska_metadata_creation_time(&s->metadata, AV_RB64(matroska->date_utc.data));
2988 
2989     res = matroska_parse_tracks(s);
2990     if (res < 0)
2991         goto fail;
2992 
2993     attachments = attachments_list->elem;
2994     for (j = 0; j < attachments_list->nb_elem; j++) {
2995         if (!(attachments[j].filename && attachments[j].mime &&
2996               attachments[j].bin.data && attachments[j].bin.size > 0)) {
2997             av_log(matroska->ctx, AV_LOG_ERROR, "incomplete attachment\n");
2998         } else {
2999             AVStream *st = avformat_new_stream(s, NULL);
3000             if (!st)
3001                 break;
3002             av_dict_set(&st->metadata, "filename", attachments[j].filename, 0);
3003             av_dict_set(&st->metadata, "mimetype", attachments[j].mime, 0);
3004             if (attachments[j].description)
3005                 av_dict_set(&st->metadata, "title", attachments[j].description, 0);
3006             st->codecpar->codec_id   = AV_CODEC_ID_NONE;
3007 
3008             for (i = 0; mkv_image_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
3009                 if (av_strstart(attachments[j].mime, mkv_image_mime_tags[i].str, NULL)) {
3010                     st->codecpar->codec_id = mkv_image_mime_tags[i].id;
3011                     break;
3012                 }
3013             }
3014 
3015             attachments[j].stream = st;
3016 
3017             if (st->codecpar->codec_id != AV_CODEC_ID_NONE) {
3018                 AVPacket *pkt = &st->attached_pic;
3019 
3020                 st->disposition         |= AV_DISPOSITION_ATTACHED_PIC;
3021                 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
3022 
3023                 av_packet_unref(pkt);
3024                 pkt->buf          = attachments[j].bin.buf;
3025                 attachments[j].bin.buf = NULL;
3026                 pkt->data         = attachments[j].bin.data;
3027                 pkt->size         = attachments[j].bin.size;
3028                 pkt->stream_index = st->index;
3029                 pkt->flags       |= AV_PKT_FLAG_KEY;
3030             } else {
3031                 st->codecpar->codec_type = AVMEDIA_TYPE_ATTACHMENT;
3032                 if (ff_alloc_extradata(st->codecpar, attachments[j].bin.size))
3033                     break;
3034                 memcpy(st->codecpar->extradata, attachments[j].bin.data,
3035                        attachments[j].bin.size);
3036 
3037                 for (i = 0; mkv_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
3038                     if (av_strstart(attachments[j].mime, mkv_mime_tags[i].str, NULL)) {
3039                         st->codecpar->codec_id = mkv_mime_tags[i].id;
3040                         break;
3041                     }
3042                 }
3043             }
3044         }
3045     }
3046 
3047     chapters = chapters_list->elem;
3048     for (i = 0; i < chapters_list->nb_elem; i++)
3049         if (chapters[i].start != AV_NOPTS_VALUE && chapters[i].uid &&
3050             (max_start == 0 || chapters[i].start > max_start)) {
3051             chapters[i].chapter =
3052                 avpriv_new_chapter(s, chapters[i].uid,
3053                                    (AVRational) { 1, 1000000000 },
3054                                    chapters[i].start, chapters[i].end,
3055                                    chapters[i].title);
3056             max_start = chapters[i].start;
3057         }
3058 
3059     matroska_add_index_entries(matroska);
3060 
3061     matroska_convert_tags(s);
3062 
3063     return 0;
3064 fail:
3065     matroska_read_close(s);
3066     return res;
3067 }
3068 
3069 /*
3070  * Put one packet in an application-supplied AVPacket struct.
3071  * Returns 0 on success or -1 on failure.
3072  */
matroska_deliver_packet(MatroskaDemuxContext * matroska,AVPacket * pkt)3073 static int matroska_deliver_packet(MatroskaDemuxContext *matroska,
3074                                    AVPacket *pkt)
3075 {
3076     if (matroska->queue) {
3077         MatroskaTrack *tracks = matroska->tracks.elem;
3078         MatroskaTrack *track;
3079 
3080         avpriv_packet_list_get(&matroska->queue, &matroska->queue_end, pkt);
3081         track = &tracks[pkt->stream_index];
3082         if (track->has_palette) {
3083             uint8_t *pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, AVPALETTE_SIZE);
3084             if (!pal) {
3085                 av_log(matroska->ctx, AV_LOG_ERROR, "Cannot append palette to packet\n");
3086             } else {
3087                 memcpy(pal, track->palette, AVPALETTE_SIZE);
3088             }
3089             track->has_palette = 0;
3090         }
3091         return 0;
3092     }
3093 
3094     return -1;
3095 }
3096 
3097 /*
3098  * Free all packets in our internal queue.
3099  */
matroska_clear_queue(MatroskaDemuxContext * matroska)3100 static void matroska_clear_queue(MatroskaDemuxContext *matroska)
3101 {
3102     avpriv_packet_list_free(&matroska->queue, &matroska->queue_end);
3103 }
3104 
matroska_parse_laces(MatroskaDemuxContext * matroska,uint8_t ** buf,int size,int type,AVIOContext * pb,uint32_t lace_size[256],int * laces)3105 static int matroska_parse_laces(MatroskaDemuxContext *matroska, uint8_t **buf,
3106                                 int size, int type, AVIOContext *pb,
3107                                 uint32_t lace_size[256], int *laces)
3108 {
3109     int n;
3110     uint8_t *data = *buf;
3111 
3112     if (!type) {
3113         *laces    = 1;
3114         lace_size[0] = size;
3115         return 0;
3116     }
3117 
3118     if (size <= 0)
3119         return AVERROR_INVALIDDATA;
3120 
3121     *laces = *data + 1;
3122     data  += 1;
3123     size  -= 1;
3124 
3125     switch (type) {
3126     case 0x1: /* Xiph lacing */
3127     {
3128         uint8_t temp;
3129         uint32_t total = 0;
3130         for (n = 0; n < *laces - 1; n++) {
3131             lace_size[n] = 0;
3132 
3133             do {
3134                 if (size <= total)
3135                     return AVERROR_INVALIDDATA;
3136                 temp          = *data;
3137                 total        += temp;
3138                 lace_size[n] += temp;
3139                 data         += 1;
3140                 size         -= 1;
3141             } while (temp ==  0xff);
3142         }
3143         if (size < total)
3144             return AVERROR_INVALIDDATA;
3145 
3146         lace_size[n] = size - total;
3147         break;
3148     }
3149 
3150     case 0x2: /* fixed-size lacing */
3151         if (size % (*laces))
3152             return AVERROR_INVALIDDATA;
3153         for (n = 0; n < *laces; n++)
3154             lace_size[n] = size / *laces;
3155         break;
3156 
3157     case 0x3: /* EBML lacing */
3158     {
3159         uint64_t num;
3160         uint64_t total;
3161         int offset;
3162 
3163         avio_skip(pb, 4);
3164 
3165         n = ebml_read_num(matroska, pb, 8, &num, 1);
3166         if (n < 0)
3167             return n;
3168         if (num > INT_MAX)
3169             return AVERROR_INVALIDDATA;
3170 
3171         total = lace_size[0] = num;
3172         offset = n;
3173         for (n = 1; n < *laces - 1; n++) {
3174             int64_t snum;
3175             int r;
3176             r = matroska_ebmlnum_sint(matroska, pb, &snum);
3177             if (r < 0)
3178                 return r;
3179             if (lace_size[n - 1] + snum > (uint64_t)INT_MAX)
3180                 return AVERROR_INVALIDDATA;
3181 
3182             lace_size[n] = lace_size[n - 1] + snum;
3183             total       += lace_size[n];
3184             offset      += r;
3185         }
3186         data += offset;
3187         size -= offset;
3188         if (size < total)
3189             return AVERROR_INVALIDDATA;
3190 
3191         lace_size[*laces - 1] = size - total;
3192         break;
3193     }
3194     }
3195 
3196     *buf = data;
3197 
3198     return 0;
3199 }
3200 
matroska_parse_rm_audio(MatroskaDemuxContext * matroska,MatroskaTrack * track,AVStream * st,uint8_t * data,int size,uint64_t timecode,int64_t pos)3201 static int matroska_parse_rm_audio(MatroskaDemuxContext *matroska,
3202                                    MatroskaTrack *track, AVStream *st,
3203                                    uint8_t *data, int size, uint64_t timecode,
3204                                    int64_t pos)
3205 {
3206     const int a   = st->codecpar->block_align;
3207     const int sps = track->audio.sub_packet_size;
3208     const int cfs = track->audio.coded_framesize;
3209     const int h   = track->audio.sub_packet_h;
3210     const int w   = track->audio.frame_size;
3211     int y   = track->audio.sub_packet_cnt;
3212     int x;
3213 
3214     if (!track->audio.pkt_cnt) {
3215         if (track->audio.sub_packet_cnt == 0)
3216             track->audio.buf_timecode = timecode;
3217         if (st->codecpar->codec_id == AV_CODEC_ID_RA_288) {
3218             if (size < cfs * h / 2) {
3219                 av_log(matroska->ctx, AV_LOG_ERROR,
3220                        "Corrupt int4 RM-style audio packet size\n");
3221                 return AVERROR_INVALIDDATA;
3222             }
3223             for (x = 0; x < h / 2; x++)
3224                 memcpy(track->audio.buf + x * 2 * w + y * cfs,
3225                        data + x * cfs, cfs);
3226         } else if (st->codecpar->codec_id == AV_CODEC_ID_SIPR) {
3227             if (size < w) {
3228                 av_log(matroska->ctx, AV_LOG_ERROR,
3229                        "Corrupt sipr RM-style audio packet size\n");
3230                 return AVERROR_INVALIDDATA;
3231             }
3232             memcpy(track->audio.buf + y * w, data, w);
3233         } else {
3234             if (size < w) {
3235                 av_log(matroska->ctx, AV_LOG_ERROR,
3236                        "Corrupt generic RM-style audio packet size\n");
3237                 return AVERROR_INVALIDDATA;
3238             }
3239             for (x = 0; x < w / sps; x++)
3240                 memcpy(track->audio.buf +
3241                        sps * (h * x + ((h + 1) / 2) * (y & 1) + (y >> 1)),
3242                        data + x * sps, sps);
3243         }
3244 
3245         if (++track->audio.sub_packet_cnt >= h) {
3246             if (st->codecpar->codec_id == AV_CODEC_ID_SIPR)
3247                 ff_rm_reorder_sipr_data(track->audio.buf, h, w);
3248             track->audio.sub_packet_cnt = 0;
3249             track->audio.pkt_cnt        = h * w / a;
3250         }
3251     }
3252 
3253     while (track->audio.pkt_cnt) {
3254         int ret;
3255         AVPacket *pkt = matroska->pkt;
3256 
3257         ret = av_new_packet(pkt, a);
3258         if (ret < 0) {
3259             return ret;
3260         }
3261         memcpy(pkt->data,
3262                track->audio.buf + a * (h * w / a - track->audio.pkt_cnt--),
3263                a);
3264         pkt->pts                  = track->audio.buf_timecode;
3265         track->audio.buf_timecode = AV_NOPTS_VALUE;
3266         pkt->pos                  = pos;
3267         pkt->stream_index         = st->index;
3268         ret = avpriv_packet_list_put(&matroska->queue, &matroska->queue_end, pkt, NULL, 0);
3269         if (ret < 0) {
3270             av_packet_unref(pkt);
3271             return AVERROR(ENOMEM);
3272         }
3273     }
3274 
3275     return 0;
3276 }
3277 
3278 /* reconstruct full wavpack blocks from mangled matroska ones */
matroska_parse_wavpack(MatroskaTrack * track,uint8_t ** data,int * size)3279 static int matroska_parse_wavpack(MatroskaTrack *track,
3280                                   uint8_t **data, int *size)
3281 {
3282     uint8_t *dst = NULL;
3283     uint8_t *src = *data;
3284     int dstlen   = 0;
3285     int srclen   = *size;
3286     uint32_t samples;
3287     uint16_t ver;
3288     int ret, offset = 0;
3289 
3290     if (srclen < 12)
3291         return AVERROR_INVALIDDATA;
3292 
3293     av_assert1(track->stream->codecpar->extradata_size >= 2);
3294     ver = AV_RL16(track->stream->codecpar->extradata);
3295 
3296     samples = AV_RL32(src);
3297     src    += 4;
3298     srclen -= 4;
3299 
3300     while (srclen >= 8) {
3301         int multiblock;
3302         uint32_t blocksize;
3303         uint8_t *tmp;
3304 
3305         uint32_t flags = AV_RL32(src);
3306         uint32_t crc   = AV_RL32(src + 4);
3307         src    += 8;
3308         srclen -= 8;
3309 
3310         multiblock = (flags & 0x1800) != 0x1800;
3311         if (multiblock) {
3312             if (srclen < 4) {
3313                 ret = AVERROR_INVALIDDATA;
3314                 goto fail;
3315             }
3316             blocksize = AV_RL32(src);
3317             src      += 4;
3318             srclen   -= 4;
3319         } else
3320             blocksize = srclen;
3321 
3322         if (blocksize > srclen) {
3323             ret = AVERROR_INVALIDDATA;
3324             goto fail;
3325         }
3326 
3327         tmp = av_realloc(dst, dstlen + blocksize + 32 + AV_INPUT_BUFFER_PADDING_SIZE);
3328         if (!tmp) {
3329             ret = AVERROR(ENOMEM);
3330             goto fail;
3331         }
3332         dst     = tmp;
3333         dstlen += blocksize + 32;
3334 
3335         AV_WL32(dst + offset, MKTAG('w', 'v', 'p', 'k'));   // tag
3336         AV_WL32(dst + offset +  4, blocksize + 24);         // blocksize - 8
3337         AV_WL16(dst + offset +  8, ver);                    // version
3338         AV_WL16(dst + offset + 10, 0);                      // track/index_no
3339         AV_WL32(dst + offset + 12, 0);                      // total samples
3340         AV_WL32(dst + offset + 16, 0);                      // block index
3341         AV_WL32(dst + offset + 20, samples);                // number of samples
3342         AV_WL32(dst + offset + 24, flags);                  // flags
3343         AV_WL32(dst + offset + 28, crc);                    // crc
3344         memcpy(dst + offset + 32, src, blocksize);          // block data
3345 
3346         src    += blocksize;
3347         srclen -= blocksize;
3348         offset += blocksize + 32;
3349     }
3350 
3351     memset(dst + dstlen, 0, AV_INPUT_BUFFER_PADDING_SIZE);
3352 
3353     *data = dst;
3354     *size = dstlen;
3355 
3356     return 0;
3357 
3358 fail:
3359     av_freep(&dst);
3360     return ret;
3361 }
3362 
matroska_parse_prores(MatroskaTrack * track,uint8_t ** data,int * size)3363 static int matroska_parse_prores(MatroskaTrack *track,
3364                                  uint8_t **data, int *size)
3365 {
3366     uint8_t *dst;
3367     int dstlen = *size + 8;
3368 
3369     dst = av_malloc(dstlen + AV_INPUT_BUFFER_PADDING_SIZE);
3370     if (!dst)
3371         return AVERROR(ENOMEM);
3372 
3373     AV_WB32(dst, dstlen);
3374     AV_WB32(dst + 4, MKBETAG('i', 'c', 'p', 'f'));
3375     memcpy(dst + 8, *data, dstlen - 8);
3376     memset(dst + dstlen, 0, AV_INPUT_BUFFER_PADDING_SIZE);
3377 
3378     *data = dst;
3379     *size = dstlen;
3380 
3381     return 0;
3382 }
3383 
matroska_parse_webvtt(MatroskaDemuxContext * matroska,MatroskaTrack * track,AVStream * st,uint8_t * data,int data_len,uint64_t timecode,uint64_t duration,int64_t pos)3384 static int matroska_parse_webvtt(MatroskaDemuxContext *matroska,
3385                                  MatroskaTrack *track,
3386                                  AVStream *st,
3387                                  uint8_t *data, int data_len,
3388                                  uint64_t timecode,
3389                                  uint64_t duration,
3390                                  int64_t pos)
3391 {
3392     AVPacket *pkt = matroska->pkt;
3393     uint8_t *id, *settings, *text, *buf;
3394     int id_len, settings_len, text_len;
3395     uint8_t *p, *q;
3396     int err;
3397 
3398     if (data_len <= 0)
3399         return AVERROR_INVALIDDATA;
3400 
3401     p = data;
3402     q = data + data_len;
3403 
3404     id = p;
3405     id_len = -1;
3406     while (p < q) {
3407         if (*p == '\r' || *p == '\n') {
3408             id_len = p - id;
3409             if (*p == '\r')
3410                 p++;
3411             break;
3412         }
3413         p++;
3414     }
3415 
3416     if (p >= q || *p != '\n')
3417         return AVERROR_INVALIDDATA;
3418     p++;
3419 
3420     settings = p;
3421     settings_len = -1;
3422     while (p < q) {
3423         if (*p == '\r' || *p == '\n') {
3424             settings_len = p - settings;
3425             if (*p == '\r')
3426                 p++;
3427             break;
3428         }
3429         p++;
3430     }
3431 
3432     if (p >= q || *p != '\n')
3433         return AVERROR_INVALIDDATA;
3434     p++;
3435 
3436     text = p;
3437     text_len = q - p;
3438     while (text_len > 0) {
3439         const int len = text_len - 1;
3440         const uint8_t c = p[len];
3441         if (c != '\r' && c != '\n')
3442             break;
3443         text_len = len;
3444     }
3445 
3446     if (text_len <= 0)
3447         return AVERROR_INVALIDDATA;
3448 
3449     err = av_new_packet(pkt, text_len);
3450     if (err < 0) {
3451         return err;
3452     }
3453 
3454     memcpy(pkt->data, text, text_len);
3455 
3456     if (id_len > 0) {
3457         buf = av_packet_new_side_data(pkt,
3458                                       AV_PKT_DATA_WEBVTT_IDENTIFIER,
3459                                       id_len);
3460         if (!buf) {
3461             av_packet_unref(pkt);
3462             return AVERROR(ENOMEM);
3463         }
3464         memcpy(buf, id, id_len);
3465     }
3466 
3467     if (settings_len > 0) {
3468         buf = av_packet_new_side_data(pkt,
3469                                       AV_PKT_DATA_WEBVTT_SETTINGS,
3470                                       settings_len);
3471         if (!buf) {
3472             av_packet_unref(pkt);
3473             return AVERROR(ENOMEM);
3474         }
3475         memcpy(buf, settings, settings_len);
3476     }
3477 
3478     // Do we need this for subtitles?
3479     // pkt->flags = AV_PKT_FLAG_KEY;
3480 
3481     pkt->stream_index = st->index;
3482     pkt->pts = timecode;
3483 
3484     // Do we need this for subtitles?
3485     // pkt->dts = timecode;
3486 
3487     pkt->duration = duration;
3488     pkt->pos = pos;
3489 
3490     err = avpriv_packet_list_put(&matroska->queue, &matroska->queue_end, pkt, NULL, 0);
3491     if (err < 0) {
3492         av_packet_unref(pkt);
3493         return AVERROR(ENOMEM);
3494     }
3495 
3496     return 0;
3497 }
3498 
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)3499 static int matroska_parse_frame(MatroskaDemuxContext *matroska,
3500                                 MatroskaTrack *track, AVStream *st,
3501                                 AVBufferRef *buf, uint8_t *data, int pkt_size,
3502                                 uint64_t timecode, uint64_t lace_duration,
3503                                 int64_t pos, int is_keyframe,
3504                                 uint8_t *additional, uint64_t additional_id, int additional_size,
3505                                 int64_t discard_padding)
3506 {
3507     uint8_t *pkt_data = data;
3508     int res = 0;
3509     AVPacket *pkt = matroska->pkt;
3510 
3511     if (st->codecpar->codec_id == AV_CODEC_ID_WAVPACK) {
3512         res = matroska_parse_wavpack(track, &pkt_data, &pkt_size);
3513         if (res < 0) {
3514             av_log(matroska->ctx, AV_LOG_ERROR,
3515                    "Error parsing a wavpack block.\n");
3516             goto fail;
3517         }
3518         if (!buf)
3519             av_freep(&data);
3520         buf = NULL;
3521     }
3522 
3523     if (st->codecpar->codec_id == AV_CODEC_ID_PRORES &&
3524         AV_RB32(pkt_data + 4)  != MKBETAG('i', 'c', 'p', 'f')) {
3525         res = matroska_parse_prores(track, &pkt_data, &pkt_size);
3526         if (res < 0) {
3527             av_log(matroska->ctx, AV_LOG_ERROR,
3528                    "Error parsing a prores block.\n");
3529             goto fail;
3530         }
3531         if (!buf)
3532             av_freep(&data);
3533         buf = NULL;
3534     }
3535 
3536     if (!pkt_size && !additional_size)
3537         goto no_output;
3538 
3539     av_packet_unref(pkt);
3540     if (!buf)
3541         pkt->buf = av_buffer_create(pkt_data, pkt_size + AV_INPUT_BUFFER_PADDING_SIZE,
3542                                     NULL, NULL, 0);
3543     else
3544         pkt->buf = av_buffer_ref(buf);
3545 
3546     if (!pkt->buf) {
3547         res = AVERROR(ENOMEM);
3548         goto fail;
3549     }
3550 
3551     pkt->data         = pkt_data;
3552     pkt->size         = pkt_size;
3553     pkt->flags        = is_keyframe;
3554     pkt->stream_index = st->index;
3555 
3556     if (additional_size > 0) {
3557         uint8_t *side_data = av_packet_new_side_data(pkt,
3558                                                      AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
3559                                                      additional_size + 8);
3560         if (!side_data) {
3561             av_packet_unref(pkt);
3562             return AVERROR(ENOMEM);
3563         }
3564         AV_WB64(side_data, additional_id);
3565         memcpy(side_data + 8, additional, additional_size);
3566     }
3567 
3568     if (discard_padding) {
3569         uint8_t *side_data = av_packet_new_side_data(pkt,
3570                                                      AV_PKT_DATA_SKIP_SAMPLES,
3571                                                      10);
3572         if (!side_data) {
3573             av_packet_unref(pkt);
3574             return AVERROR(ENOMEM);
3575         }
3576         discard_padding = av_rescale_q(discard_padding,
3577                                             (AVRational){1, 1000000000},
3578                                             (AVRational){1, st->codecpar->sample_rate});
3579         if (discard_padding > 0) {
3580             AV_WL32(side_data + 4, discard_padding);
3581         } else {
3582             AV_WL32(side_data, -discard_padding);
3583         }
3584     }
3585 
3586     if (track->ms_compat)
3587         pkt->dts = timecode;
3588     else
3589         pkt->pts = timecode;
3590     pkt->pos = pos;
3591     pkt->duration = lace_duration;
3592 
3593 #if FF_API_CONVERGENCE_DURATION
3594 FF_DISABLE_DEPRECATION_WARNINGS
3595     if (st->codecpar->codec_id == AV_CODEC_ID_SUBRIP) {
3596         pkt->convergence_duration = lace_duration;
3597     }
3598 FF_ENABLE_DEPRECATION_WARNINGS
3599 #endif
3600 
3601     res = avpriv_packet_list_put(&matroska->queue, &matroska->queue_end, pkt, NULL, 0);
3602     if (res < 0) {
3603         av_packet_unref(pkt);
3604         return AVERROR(ENOMEM);
3605     }
3606 
3607     return 0;
3608 
3609 no_output:
3610 fail:
3611     if (!buf)
3612         av_free(pkt_data);
3613     return res;
3614 }
3615 
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)3616 static int matroska_parse_block(MatroskaDemuxContext *matroska, AVBufferRef *buf, uint8_t *data,
3617                                 int size, int64_t pos, uint64_t cluster_time,
3618                                 uint64_t block_duration, int is_keyframe,
3619                                 uint8_t *additional, uint64_t additional_id, int additional_size,
3620                                 int64_t cluster_pos, int64_t discard_padding)
3621 {
3622     uint64_t timecode = AV_NOPTS_VALUE;
3623     MatroskaTrack *track;
3624     AVIOContext pb;
3625     int res = 0;
3626     AVStream *st;
3627     int16_t block_time;
3628     uint32_t lace_size[256];
3629     int n, flags, laces = 0;
3630     uint64_t num;
3631     int trust_default_duration;
3632 
3633     ffio_init_context(&pb, data, size, 0, NULL, NULL, NULL, NULL);
3634 
3635     if ((n = ebml_read_num(matroska, &pb, 8, &num, 1)) < 0)
3636         return n;
3637     data += n;
3638     size -= n;
3639 
3640     track = matroska_find_track_by_num(matroska, num);
3641     if (!track || size < 3)
3642         return AVERROR_INVALIDDATA;
3643 
3644     if (!(st = track->stream)) {
3645         av_log(matroska->ctx, AV_LOG_VERBOSE,
3646                "No stream associated to TrackNumber %"PRIu64". "
3647                "Ignoring Block with this TrackNumber.\n", num);
3648         return 0;
3649     }
3650 
3651     if (st->discard >= AVDISCARD_ALL)
3652         return res;
3653     if (block_duration > INT64_MAX)
3654         block_duration = INT64_MAX;
3655 
3656     block_time = sign_extend(AV_RB16(data), 16);
3657     data      += 2;
3658     flags      = *data++;
3659     size      -= 3;
3660     if (is_keyframe == -1)
3661         is_keyframe = flags & 0x80 ? AV_PKT_FLAG_KEY : 0;
3662 
3663     if (cluster_time != (uint64_t) -1 &&
3664         (block_time >= 0 || cluster_time >= -block_time)) {
3665         uint64_t timecode_cluster_in_track_tb = (double) cluster_time / track->time_scale;
3666         timecode = timecode_cluster_in_track_tb + block_time - track->codec_delay_in_track_tb;
3667         if (track->type == MATROSKA_TRACK_TYPE_SUBTITLE &&
3668             timecode < track->end_timecode)
3669             is_keyframe = 0;  /* overlapping subtitles are not key frame */
3670         if (is_keyframe) {
3671             ff_reduce_index(matroska->ctx, st->index);
3672             av_add_index_entry(st, cluster_pos, timecode, 0, 0,
3673                                AVINDEX_KEYFRAME);
3674         }
3675     }
3676 
3677     if (matroska->skip_to_keyframe &&
3678         track->type != MATROSKA_TRACK_TYPE_SUBTITLE) {
3679         // Compare signed timecodes. Timecode may be negative due to codec delay
3680         // offset. We don't support timestamps greater than int64_t anyway - see
3681         // AVPacket's pts.
3682         if ((int64_t)timecode < (int64_t)matroska->skip_to_timecode)
3683             return res;
3684         if (is_keyframe)
3685             matroska->skip_to_keyframe = 0;
3686         else if (!st->internal->skip_to_keyframe) {
3687             av_log(matroska->ctx, AV_LOG_ERROR, "File is broken, keyframes not correctly marked!\n");
3688             matroska->skip_to_keyframe = 0;
3689         }
3690     }
3691 
3692     res = matroska_parse_laces(matroska, &data, size, (flags & 0x06) >> 1,
3693                                &pb, lace_size, &laces);
3694     if (res < 0) {
3695         av_log(matroska->ctx, AV_LOG_ERROR, "Error parsing frame sizes.\n");
3696         return res;
3697     }
3698 
3699     trust_default_duration = track->default_duration != 0;
3700     if (track->audio.samplerate == 8000 && trust_default_duration) {
3701         // If this is needed for more codecs, then add them here
3702         if (st->codecpar->codec_id == AV_CODEC_ID_AC3) {
3703             if (track->audio.samplerate != st->codecpar->sample_rate || !st->codecpar->frame_size)
3704                 trust_default_duration = 0;
3705         }
3706     }
3707 
3708     if (!block_duration && trust_default_duration)
3709         block_duration = track->default_duration * laces / matroska->time_scale;
3710 
3711     if (cluster_time != (uint64_t)-1 && (block_time >= 0 || cluster_time >= -block_time))
3712         track->end_timecode =
3713             FFMAX(track->end_timecode, timecode + block_duration);
3714 
3715     for (n = 0; n < laces; n++) {
3716         int64_t lace_duration = block_duration*(n+1) / laces - block_duration*n / laces;
3717         uint8_t *out_data = data;
3718         int      out_size = lace_size[n];
3719 
3720         if (track->needs_decoding) {
3721             res = matroska_decode_buffer(&out_data, &out_size, track);
3722             if (res < 0)
3723                 return res;
3724             /* Given that we are here means that out_data is no longer
3725              * owned by buf, so set it to NULL. This depends upon
3726              * zero-length header removal compression being ignored. */
3727             av_assert1(out_data != data);
3728             buf = NULL;
3729         }
3730 
3731         if (track->audio.buf) {
3732             res = matroska_parse_rm_audio(matroska, track, st,
3733                                           out_data, out_size,
3734                                           timecode, pos);
3735             if (!buf)
3736                 av_free(out_data);
3737             if (res)
3738                 return res;
3739         } else if (st->codecpar->codec_id == AV_CODEC_ID_WEBVTT) {
3740             res = matroska_parse_webvtt(matroska, track, st,
3741                                         out_data, out_size,
3742                                         timecode, lace_duration,
3743                                         pos);
3744             if (!buf)
3745                 av_free(out_data);
3746             if (res)
3747                 return res;
3748         } else {
3749             res = matroska_parse_frame(matroska, track, st, buf, out_data,
3750                                        out_size, timecode, lace_duration,
3751                                        pos, !n ? is_keyframe : 0,
3752                                        additional, additional_id, additional_size,
3753                                        discard_padding);
3754             if (res)
3755                 return res;
3756         }
3757 
3758         if (timecode != AV_NOPTS_VALUE)
3759             timecode = lace_duration ? timecode + lace_duration : AV_NOPTS_VALUE;
3760         data += lace_size[n];
3761     }
3762 
3763     return 0;
3764 }
3765 
matroska_parse_cluster(MatroskaDemuxContext * matroska)3766 static int matroska_parse_cluster(MatroskaDemuxContext *matroska)
3767 {
3768     MatroskaCluster *cluster = &matroska->current_cluster;
3769     MatroskaBlock     *block = &cluster->block;
3770     int res;
3771 
3772     av_assert0(matroska->num_levels <= 2);
3773 
3774     if (matroska->num_levels == 1) {
3775         res = ebml_parse(matroska, matroska_segment, NULL);
3776 
3777         if (res == 1) {
3778             /* Found a cluster: subtract the size of the ID already read. */
3779             cluster->pos = avio_tell(matroska->ctx->pb) - 4;
3780 
3781             res = ebml_parse(matroska, matroska_cluster_enter, cluster);
3782             if (res < 0)
3783                 return res;
3784         }
3785     }
3786 
3787     if (matroska->num_levels == 2) {
3788         /* We are inside a cluster. */
3789         res = ebml_parse(matroska, matroska_cluster_parsing, cluster);
3790 
3791         if (res >= 0 && block->bin.size > 0) {
3792             int is_keyframe = block->non_simple ? block->reference.count == 0 : -1;
3793             uint8_t* additional = block->additional.size > 0 ?
3794                                     block->additional.data : NULL;
3795 
3796             res = matroska_parse_block(matroska, block->bin.buf, block->bin.data,
3797                                        block->bin.size, block->bin.pos,
3798                                        cluster->timecode, block->duration,
3799                                        is_keyframe, additional, block->additional_id,
3800                                        block->additional.size, cluster->pos,
3801                                        block->discard_padding);
3802         }
3803 
3804         ebml_free(matroska_blockgroup, block);
3805         memset(block, 0, sizeof(*block));
3806     } else if (!matroska->num_levels) {
3807         if (!avio_feof(matroska->ctx->pb)) {
3808             avio_r8(matroska->ctx->pb);
3809             if (!avio_feof(matroska->ctx->pb)) {
3810                 av_log(matroska->ctx, AV_LOG_WARNING, "File extends beyond "
3811                        "end of segment.\n");
3812                 return AVERROR_INVALIDDATA;
3813             }
3814         }
3815         matroska->done = 1;
3816         return AVERROR_EOF;
3817     }
3818 
3819     return res;
3820 }
3821 
matroska_read_packet(AVFormatContext * s,AVPacket * pkt)3822 static int matroska_read_packet(AVFormatContext *s, AVPacket *pkt)
3823 {
3824     MatroskaDemuxContext *matroska = s->priv_data;
3825     int ret = 0;
3826 
3827     if (matroska->resync_pos == -1) {
3828         // This can only happen if generic seeking has been used.
3829         matroska->resync_pos = avio_tell(s->pb);
3830     }
3831 
3832     while (matroska_deliver_packet(matroska, pkt)) {
3833         if (matroska->done)
3834             return (ret < 0) ? ret : AVERROR_EOF;
3835         if (matroska_parse_cluster(matroska) < 0 && !matroska->done)
3836             ret = matroska_resync(matroska, matroska->resync_pos);
3837     }
3838 
3839     return 0;
3840 }
3841 
matroska_read_seek(AVFormatContext * s,int stream_index,int64_t timestamp,int flags)3842 static int matroska_read_seek(AVFormatContext *s, int stream_index,
3843                               int64_t timestamp, int flags)
3844 {
3845     MatroskaDemuxContext *matroska = s->priv_data;
3846     MatroskaTrack *tracks = NULL;
3847     AVStream *st = s->streams[stream_index];
3848     int i, index;
3849 
3850     /* Parse the CUES now since we need the index data to seek. */
3851     if (matroska->cues_parsing_deferred > 0) {
3852         matroska->cues_parsing_deferred = 0;
3853         matroska_parse_cues(matroska);
3854     }
3855 
3856     if (!st->nb_index_entries)
3857         goto err;
3858     timestamp = FFMAX(timestamp, st->index_entries[0].timestamp);
3859 
3860     if ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->nb_index_entries - 1) {
3861         matroska_reset_status(matroska, 0, st->index_entries[st->nb_index_entries - 1].pos);
3862         while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0 || index == st->nb_index_entries - 1) {
3863             matroska_clear_queue(matroska);
3864             if (matroska_parse_cluster(matroska) < 0)
3865                 break;
3866         }
3867     }
3868 
3869     matroska_clear_queue(matroska);
3870     if (index < 0 || (matroska->cues_parsing_deferred < 0 && index == st->nb_index_entries - 1))
3871         goto err;
3872 
3873     tracks = matroska->tracks.elem;
3874     for (i = 0; i < matroska->tracks.nb_elem; i++) {
3875         tracks[i].audio.pkt_cnt        = 0;
3876         tracks[i].audio.sub_packet_cnt = 0;
3877         tracks[i].audio.buf_timecode   = AV_NOPTS_VALUE;
3878         tracks[i].end_timecode         = 0;
3879     }
3880 
3881     /* We seek to a level 1 element, so set the appropriate status. */
3882     matroska_reset_status(matroska, 0, st->index_entries[index].pos);
3883     if (flags & AVSEEK_FLAG_ANY) {
3884         st->internal->skip_to_keyframe = 0;
3885         matroska->skip_to_timecode = timestamp;
3886     } else {
3887         st->internal->skip_to_keyframe = 1;
3888         matroska->skip_to_timecode = st->index_entries[index].timestamp;
3889     }
3890     matroska->skip_to_keyframe = 1;
3891     matroska->done             = 0;
3892     ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
3893     return 0;
3894 err:
3895     // slightly hackish but allows proper fallback to
3896     // the generic seeking code.
3897     matroska_reset_status(matroska, 0, -1);
3898     matroska->resync_pos = -1;
3899     matroska_clear_queue(matroska);
3900     st->internal->skip_to_keyframe =
3901     matroska->skip_to_keyframe = 0;
3902     matroska->done = 0;
3903     return -1;
3904 }
3905 
matroska_read_close(AVFormatContext * s)3906 static int matroska_read_close(AVFormatContext *s)
3907 {
3908     MatroskaDemuxContext *matroska = s->priv_data;
3909     MatroskaTrack *tracks = matroska->tracks.elem;
3910     int n;
3911 
3912     matroska_clear_queue(matroska);
3913     av_packet_free(&matroska->pkt);
3914 
3915     for (n = 0; n < matroska->tracks.nb_elem; n++)
3916         if (tracks[n].type == MATROSKA_TRACK_TYPE_AUDIO)
3917             av_freep(&tracks[n].audio.buf);
3918     ebml_free(matroska_segment, matroska);
3919 
3920     return 0;
3921 }
3922 
3923 typedef struct {
3924     int64_t start_time_ns;
3925     int64_t end_time_ns;
3926     int64_t start_offset;
3927     int64_t end_offset;
3928 } CueDesc;
3929 
3930 /* This function searches all the Cues and returns the CueDesc corresponding to
3931  * the timestamp ts. Returned CueDesc will be such that start_time_ns <= ts <
3932  * end_time_ns. All 4 fields will be set to -1 if ts >= file's duration.
3933  */
get_cue_desc(AVFormatContext * s,int64_t ts,int64_t cues_start)3934 static CueDesc get_cue_desc(AVFormatContext *s, int64_t ts, int64_t cues_start) {
3935     MatroskaDemuxContext *matroska = s->priv_data;
3936     CueDesc cue_desc;
3937     int i;
3938     int nb_index_entries = s->streams[0]->nb_index_entries;
3939     AVIndexEntry *index_entries = s->streams[0]->index_entries;
3940     if (ts >= matroska->duration * matroska->time_scale) return (CueDesc) {-1, -1, -1, -1};
3941     for (i = 1; i < nb_index_entries; i++) {
3942         if (index_entries[i - 1].timestamp * matroska->time_scale <= ts &&
3943             index_entries[i].timestamp * matroska->time_scale > ts) {
3944             break;
3945         }
3946     }
3947     --i;
3948     cue_desc.start_time_ns = index_entries[i].timestamp * matroska->time_scale;
3949     cue_desc.start_offset = index_entries[i].pos - matroska->segment_start;
3950     if (i != nb_index_entries - 1) {
3951         cue_desc.end_time_ns = index_entries[i + 1].timestamp * matroska->time_scale;
3952         cue_desc.end_offset = index_entries[i + 1].pos - matroska->segment_start;
3953     } else {
3954         cue_desc.end_time_ns = matroska->duration * matroska->time_scale;
3955         // FIXME: this needs special handling for files where Cues appear
3956         // before Clusters. the current logic assumes Cues appear after
3957         // Clusters.
3958         cue_desc.end_offset = cues_start - matroska->segment_start;
3959     }
3960     return cue_desc;
3961 }
3962 
webm_clusters_start_with_keyframe(AVFormatContext * s)3963 static int webm_clusters_start_with_keyframe(AVFormatContext *s)
3964 {
3965     MatroskaDemuxContext *matroska = s->priv_data;
3966     uint32_t id = matroska->current_id;
3967     int64_t cluster_pos, before_pos;
3968     int index, rv = 1;
3969     if (s->streams[0]->nb_index_entries <= 0) return 0;
3970     // seek to the first cluster using cues.
3971     index = av_index_search_timestamp(s->streams[0], 0, 0);
3972     if (index < 0)  return 0;
3973     cluster_pos = s->streams[0]->index_entries[index].pos;
3974     before_pos = avio_tell(s->pb);
3975     while (1) {
3976         uint64_t cluster_id, cluster_length;
3977         int read;
3978         AVPacket *pkt;
3979         avio_seek(s->pb, cluster_pos, SEEK_SET);
3980         // read cluster id and length
3981         read = ebml_read_num(matroska, matroska->ctx->pb, 4, &cluster_id, 1);
3982         if (read < 0 || cluster_id != 0xF43B675) // done with all clusters
3983             break;
3984         read = ebml_read_length(matroska, matroska->ctx->pb, &cluster_length);
3985         if (read < 0)
3986             break;
3987 
3988         matroska_reset_status(matroska, 0, cluster_pos);
3989         matroska_clear_queue(matroska);
3990         if (matroska_parse_cluster(matroska) < 0 ||
3991             !matroska->queue) {
3992             break;
3993         }
3994         pkt = &matroska->queue->pkt;
3995         // 4 + read is the length of the cluster id and the cluster length field.
3996         cluster_pos += 4 + read + cluster_length;
3997         if (!(pkt->flags & AV_PKT_FLAG_KEY)) {
3998             rv = 0;
3999             break;
4000         }
4001     }
4002 
4003     /* Restore the status after matroska_read_header: */
4004     matroska_reset_status(matroska, id, before_pos);
4005 
4006     return rv;
4007 }
4008 
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)4009 static int buffer_size_after_time_downloaded(int64_t time_ns, double search_sec, int64_t bps,
4010                                              double min_buffer, double* buffer,
4011                                              double* sec_to_download, AVFormatContext *s,
4012                                              int64_t cues_start)
4013 {
4014     double nano_seconds_per_second = 1000000000.0;
4015     double time_sec = time_ns / nano_seconds_per_second;
4016     int rv = 0;
4017     int64_t time_to_search_ns = (int64_t)(search_sec * nano_seconds_per_second);
4018     int64_t end_time_ns = time_ns + time_to_search_ns;
4019     double sec_downloaded = 0.0;
4020     CueDesc desc_curr = get_cue_desc(s, time_ns, cues_start);
4021     if (desc_curr.start_time_ns == -1)
4022       return -1;
4023     *sec_to_download = 0.0;
4024 
4025     // Check for non cue start time.
4026     if (time_ns > desc_curr.start_time_ns) {
4027       int64_t cue_nano = desc_curr.end_time_ns - time_ns;
4028       double percent = (double)(cue_nano) / (desc_curr.end_time_ns - desc_curr.start_time_ns);
4029       double cueBytes = (desc_curr.end_offset - desc_curr.start_offset) * percent;
4030       double timeToDownload = (cueBytes * 8.0) / bps;
4031 
4032       sec_downloaded += (cue_nano / nano_seconds_per_second) - timeToDownload;
4033       *sec_to_download += timeToDownload;
4034 
4035       // Check if the search ends within the first cue.
4036       if (desc_curr.end_time_ns >= end_time_ns) {
4037           double desc_end_time_sec = desc_curr.end_time_ns / nano_seconds_per_second;
4038           double percent_to_sub = search_sec / (desc_end_time_sec - time_sec);
4039           sec_downloaded = percent_to_sub * sec_downloaded;
4040           *sec_to_download = percent_to_sub * *sec_to_download;
4041       }
4042 
4043       if ((sec_downloaded + *buffer) <= min_buffer) {
4044           return 1;
4045       }
4046 
4047       // Get the next Cue.
4048       desc_curr = get_cue_desc(s, desc_curr.end_time_ns, cues_start);
4049     }
4050 
4051     while (desc_curr.start_time_ns != -1) {
4052         int64_t desc_bytes = desc_curr.end_offset - desc_curr.start_offset;
4053         int64_t desc_ns = desc_curr.end_time_ns - desc_curr.start_time_ns;
4054         double desc_sec = desc_ns / nano_seconds_per_second;
4055         double bits = (desc_bytes * 8.0);
4056         double time_to_download = bits / bps;
4057 
4058         sec_downloaded += desc_sec - time_to_download;
4059         *sec_to_download += time_to_download;
4060 
4061         if (desc_curr.end_time_ns >= end_time_ns) {
4062             double desc_end_time_sec = desc_curr.end_time_ns / nano_seconds_per_second;
4063             double percent_to_sub = search_sec / (desc_end_time_sec - time_sec);
4064             sec_downloaded = percent_to_sub * sec_downloaded;
4065             *sec_to_download = percent_to_sub * *sec_to_download;
4066 
4067             if ((sec_downloaded + *buffer) <= min_buffer)
4068                 rv = 1;
4069             break;
4070         }
4071 
4072         if ((sec_downloaded + *buffer) <= min_buffer) {
4073             rv = 1;
4074             break;
4075         }
4076 
4077         desc_curr = get_cue_desc(s, desc_curr.end_time_ns, cues_start);
4078     }
4079     *buffer = *buffer + sec_downloaded;
4080     return rv;
4081 }
4082 
4083 /* This function computes the bandwidth of the WebM file with the help of
4084  * buffer_size_after_time_downloaded() function. Both of these functions are
4085  * adapted from WebM Tools project and are adapted to work with FFmpeg's
4086  * Matroska parsing mechanism.
4087  *
4088  * Returns the bandwidth of the file on success; -1 on error.
4089  * */
webm_dash_manifest_compute_bandwidth(AVFormatContext * s,int64_t cues_start)4090 static int64_t webm_dash_manifest_compute_bandwidth(AVFormatContext *s, int64_t cues_start)
4091 {
4092     MatroskaDemuxContext *matroska = s->priv_data;
4093     AVStream *st = s->streams[0];
4094     double bandwidth = 0.0;
4095     int i;
4096 
4097     for (i = 0; i < st->nb_index_entries; i++) {
4098         int64_t prebuffer_ns = 1000000000;
4099         int64_t time_ns = st->index_entries[i].timestamp * matroska->time_scale;
4100         double nano_seconds_per_second = 1000000000.0;
4101         int64_t prebuffered_ns = time_ns + prebuffer_ns;
4102         double prebuffer_bytes = 0.0;
4103         int64_t temp_prebuffer_ns = prebuffer_ns;
4104         int64_t pre_bytes, pre_ns;
4105         double pre_sec, prebuffer, bits_per_second;
4106         CueDesc desc_beg = get_cue_desc(s, time_ns, cues_start);
4107 
4108         // Start with the first Cue.
4109         CueDesc desc_end = desc_beg;
4110 
4111         // Figure out how much data we have downloaded for the prebuffer. This will
4112         // be used later to adjust the bits per sample to try.
4113         while (desc_end.start_time_ns != -1 && desc_end.end_time_ns < prebuffered_ns) {
4114             // Prebuffered the entire Cue.
4115             prebuffer_bytes += desc_end.end_offset - desc_end.start_offset;
4116             temp_prebuffer_ns -= desc_end.end_time_ns - desc_end.start_time_ns;
4117             desc_end = get_cue_desc(s, desc_end.end_time_ns, cues_start);
4118         }
4119         if (desc_end.start_time_ns == -1) {
4120             // The prebuffer is larger than the duration.
4121             if (matroska->duration * matroska->time_scale >= prebuffered_ns)
4122               return -1;
4123             bits_per_second = 0.0;
4124         } else {
4125             // The prebuffer ends in the last Cue. Estimate how much data was
4126             // prebuffered.
4127             pre_bytes = desc_end.end_offset - desc_end.start_offset;
4128             pre_ns = desc_end.end_time_ns - desc_end.start_time_ns;
4129             pre_sec = pre_ns / nano_seconds_per_second;
4130             prebuffer_bytes +=
4131                 pre_bytes * ((temp_prebuffer_ns / nano_seconds_per_second) / pre_sec);
4132 
4133             prebuffer = prebuffer_ns / nano_seconds_per_second;
4134 
4135             // Set this to 0.0 in case our prebuffer buffers the entire video.
4136             bits_per_second = 0.0;
4137             do {
4138                 int64_t desc_bytes = desc_end.end_offset - desc_beg.start_offset;
4139                 int64_t desc_ns = desc_end.end_time_ns - desc_beg.start_time_ns;
4140                 double desc_sec = desc_ns / nano_seconds_per_second;
4141                 double calc_bits_per_second = (desc_bytes * 8) / desc_sec;
4142 
4143                 // Drop the bps by the percentage of bytes buffered.
4144                 double percent = (desc_bytes - prebuffer_bytes) / desc_bytes;
4145                 double mod_bits_per_second = calc_bits_per_second * percent;
4146 
4147                 if (prebuffer < desc_sec) {
4148                     double search_sec =
4149                         (double)(matroska->duration * matroska->time_scale) / nano_seconds_per_second;
4150 
4151                     // Add 1 so the bits per second should be a little bit greater than file
4152                     // datarate.
4153                     int64_t bps = (int64_t)(mod_bits_per_second) + 1;
4154                     const double min_buffer = 0.0;
4155                     double buffer = prebuffer;
4156                     double sec_to_download = 0.0;
4157 
4158                     int rv = buffer_size_after_time_downloaded(prebuffered_ns, search_sec, bps,
4159                                                                min_buffer, &buffer, &sec_to_download,
4160                                                                s, cues_start);
4161                     if (rv < 0) {
4162                         return -1;
4163                     } else if (rv == 0) {
4164                         bits_per_second = (double)(bps);
4165                         break;
4166                     }
4167                 }
4168 
4169                 desc_end = get_cue_desc(s, desc_end.end_time_ns, cues_start);
4170             } while (desc_end.start_time_ns != -1);
4171         }
4172         if (bandwidth < bits_per_second) bandwidth = bits_per_second;
4173     }
4174     return (int64_t)bandwidth;
4175 }
4176 
webm_dash_manifest_cues(AVFormatContext * s,int64_t init_range)4177 static int webm_dash_manifest_cues(AVFormatContext *s, int64_t init_range)
4178 {
4179     MatroskaDemuxContext *matroska = s->priv_data;
4180     EbmlList *seekhead_list = &matroska->seekhead;
4181     MatroskaSeekhead *seekhead = seekhead_list->elem;
4182     char *buf;
4183     int64_t cues_start = -1, cues_end = -1, before_pos, bandwidth;
4184     int i;
4185     int end = 0;
4186 
4187     // determine cues start and end positions
4188     for (i = 0; i < seekhead_list->nb_elem; i++)
4189         if (seekhead[i].id == MATROSKA_ID_CUES)
4190             break;
4191 
4192     if (i >= seekhead_list->nb_elem) return -1;
4193 
4194     before_pos = avio_tell(matroska->ctx->pb);
4195     cues_start = seekhead[i].pos + matroska->segment_start;
4196     if (avio_seek(matroska->ctx->pb, cues_start, SEEK_SET) == cues_start) {
4197         // cues_end is computed as cues_start + cues_length + length of the
4198         // Cues element ID (i.e. 4) + EBML length of the Cues element.
4199         // cues_end is inclusive and the above sum is reduced by 1.
4200         uint64_t cues_length, cues_id;
4201         int bytes_read;
4202         bytes_read = ebml_read_num   (matroska, matroska->ctx->pb, 4, &cues_id, 1);
4203         if (bytes_read < 0 || cues_id != (MATROSKA_ID_CUES & 0xfffffff))
4204             return bytes_read < 0 ? bytes_read : AVERROR_INVALIDDATA;
4205         bytes_read = ebml_read_length(matroska, matroska->ctx->pb, &cues_length);
4206         if (bytes_read < 0)
4207             return bytes_read;
4208         cues_end = cues_start + 4 + bytes_read + cues_length - 1;
4209     }
4210     avio_seek(matroska->ctx->pb, before_pos, SEEK_SET);
4211     if (cues_start == -1 || cues_end == -1) return -1;
4212 
4213     // parse the cues
4214     matroska_parse_cues(matroska);
4215 
4216     // cues start
4217     av_dict_set_int(&s->streams[0]->metadata, CUES_START, cues_start, 0);
4218 
4219     // cues end
4220     av_dict_set_int(&s->streams[0]->metadata, CUES_END, cues_end, 0);
4221 
4222     // if the file has cues at the start, fix up the init range so that
4223     // it does not include it
4224     if (cues_start <= init_range)
4225         av_dict_set_int(&s->streams[0]->metadata, INITIALIZATION_RANGE, cues_start - 1, 0);
4226 
4227     // bandwidth
4228     bandwidth = webm_dash_manifest_compute_bandwidth(s, cues_start);
4229     if (bandwidth < 0) return -1;
4230     av_dict_set_int(&s->streams[0]->metadata, BANDWIDTH, bandwidth, 0);
4231 
4232     // check if all clusters start with key frames
4233     av_dict_set_int(&s->streams[0]->metadata, CLUSTER_KEYFRAME, webm_clusters_start_with_keyframe(s), 0);
4234 
4235     // store cue point timestamps as a comma separated list for checking subsegment alignment in
4236     // the muxer. assumes that each timestamp cannot be more than 20 characters long.
4237     buf = av_malloc_array(s->streams[0]->nb_index_entries, 20);
4238     if (!buf) return -1;
4239     strcpy(buf, "");
4240     for (i = 0; i < s->streams[0]->nb_index_entries; i++) {
4241         int ret = snprintf(buf + end, 20,
4242                            "%" PRId64"%s", s->streams[0]->index_entries[i].timestamp,
4243                            i != s->streams[0]->nb_index_entries - 1 ? "," : "");
4244         if (ret <= 0 || (ret == 20 && i ==  s->streams[0]->nb_index_entries - 1)) {
4245             av_log(s, AV_LOG_ERROR, "timestamp too long.\n");
4246             av_free(buf);
4247             return AVERROR_INVALIDDATA;
4248         }
4249         end += ret;
4250     }
4251     av_dict_set(&s->streams[0]->metadata, CUE_TIMESTAMPS,
4252                 buf, AV_DICT_DONT_STRDUP_VAL);
4253 
4254     return 0;
4255 }
4256 
webm_dash_manifest_read_header(AVFormatContext * s)4257 static int webm_dash_manifest_read_header(AVFormatContext *s)
4258 {
4259     char *buf;
4260     int ret = matroska_read_header(s);
4261     int64_t init_range;
4262     MatroskaTrack *tracks;
4263     MatroskaDemuxContext *matroska = s->priv_data;
4264     if (ret) {
4265         av_log(s, AV_LOG_ERROR, "Failed to read file headers\n");
4266         return -1;
4267     }
4268     if (!matroska->tracks.nb_elem || !s->nb_streams) {
4269         av_log(s, AV_LOG_ERROR, "No track found\n");
4270         ret = AVERROR_INVALIDDATA;
4271         goto fail;
4272     }
4273 
4274     if (!matroska->is_live) {
4275         buf = av_asprintf("%g", matroska->duration);
4276         if (!buf) {
4277             ret = AVERROR(ENOMEM);
4278             goto fail;
4279         }
4280         av_dict_set(&s->streams[0]->metadata, DURATION,
4281                     buf, AV_DICT_DONT_STRDUP_VAL);
4282 
4283         // initialization range
4284         // 5 is the offset of Cluster ID.
4285         init_range = avio_tell(s->pb) - 5;
4286         av_dict_set_int(&s->streams[0]->metadata, INITIALIZATION_RANGE, init_range, 0);
4287     }
4288 
4289     // basename of the file
4290     buf = strrchr(s->url, '/');
4291     av_dict_set(&s->streams[0]->metadata, FILENAME, buf ? ++buf : s->url, 0);
4292 
4293     // track number
4294     tracks = matroska->tracks.elem;
4295     av_dict_set_int(&s->streams[0]->metadata, TRACK_NUMBER, tracks[0].num, 0);
4296 
4297     // parse the cues and populate Cue related fields
4298     if (!matroska->is_live) {
4299         ret = webm_dash_manifest_cues(s, init_range);
4300         if (ret < 0) {
4301             av_log(s, AV_LOG_ERROR, "Error parsing Cues\n");
4302             goto fail;
4303         }
4304     }
4305 
4306     // use the bandwidth from the command line if it was provided
4307     if (matroska->bandwidth > 0) {
4308         av_dict_set_int(&s->streams[0]->metadata, BANDWIDTH,
4309                         matroska->bandwidth, 0);
4310     }
4311     return 0;
4312 fail:
4313     matroska_read_close(s);
4314     return ret;
4315 }
4316 
webm_dash_manifest_read_packet(AVFormatContext * s,AVPacket * pkt)4317 static int webm_dash_manifest_read_packet(AVFormatContext *s, AVPacket *pkt)
4318 {
4319     return AVERROR_EOF;
4320 }
4321 
4322 #define OFFSET(x) offsetof(MatroskaDemuxContext, x)
4323 static const AVOption options[] = {
4324     { "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 },
4325     { "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 },
4326     { NULL },
4327 };
4328 
4329 static const AVClass webm_dash_class = {
4330     .class_name = "WebM DASH Manifest demuxer",
4331     .item_name  = av_default_item_name,
4332     .option     = options,
4333     .version    = LIBAVUTIL_VERSION_INT,
4334 };
4335 
4336 AVInputFormat ff_matroska_demuxer = {
4337     .name           = "matroska,webm",
4338     .long_name      = NULL_IF_CONFIG_SMALL("Matroska / WebM"),
4339     .extensions     = "mkv,mk3d,mka,mks,webm",
4340     .priv_data_size = sizeof(MatroskaDemuxContext),
4341     .read_probe     = matroska_probe,
4342     .read_header    = matroska_read_header,
4343     .read_packet    = matroska_read_packet,
4344     .read_close     = matroska_read_close,
4345     .read_seek      = matroska_read_seek,
4346     .mime_type      = "audio/webm,audio/x-matroska,video/webm,video/x-matroska"
4347 };
4348 
4349 AVInputFormat ff_webm_dash_manifest_demuxer = {
4350     .name           = "webm_dash_manifest",
4351     .long_name      = NULL_IF_CONFIG_SMALL("WebM DASH Manifest"),
4352     .priv_data_size = sizeof(MatroskaDemuxContext),
4353     .read_header    = webm_dash_manifest_read_header,
4354     .read_packet    = webm_dash_manifest_read_packet,
4355     .read_close     = matroska_read_close,
4356     .priv_class     = &webm_dash_class,
4357 };
4358