Attempt seeking to write EBML master sizes even if streamed
[libav.git] / libavformat / matroskaenc.c
1 /*
2 * Matroska muxer
3 * Copyright (c) 2007 David Conrad
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 #include "avformat.h"
23 #include "riff.h"
24 #include "isom.h"
25 #include "matroska.h"
26 #include "avc.h"
27 #include "flacenc.h"
28 #include "libavutil/intreadwrite.h"
29 #include "libavutil/md5.h"
30 #include "libavcodec/xiph.h"
31 #include "libavcodec/mpeg4audio.h"
32
33 typedef struct ebml_master {
34 int64_t pos; ///< absolute offset in the file where the master's elements start
35 int sizebytes; ///< how many bytes were reserved for the size
36 } ebml_master;
37
38 typedef struct mkv_seekhead_entry {
39 unsigned int elementid;
40 uint64_t segmentpos;
41 } mkv_seekhead_entry;
42
43 typedef struct mkv_seekhead {
44 int64_t filepos;
45 int64_t segment_offset; ///< the file offset to the beginning of the segment
46 int reserved_size; ///< -1 if appending to file
47 int max_entries;
48 mkv_seekhead_entry *entries;
49 int num_entries;
50 } mkv_seekhead;
51
52 typedef struct {
53 uint64_t pts;
54 int tracknum;
55 int64_t cluster_pos; ///< file offset of the cluster containing the block
56 } mkv_cuepoint;
57
58 typedef struct {
59 int64_t segment_offset;
60 mkv_cuepoint *entries;
61 int num_entries;
62 } mkv_cues;
63
64 typedef struct MatroskaMuxContext {
65 ebml_master segment;
66 int64_t segment_offset;
67 int64_t segment_uid;
68 ebml_master cluster;
69 int64_t cluster_pos; ///< file offset of the current cluster
70 uint64_t cluster_pts;
71 int64_t duration_offset;
72 uint64_t duration;
73 mkv_seekhead *main_seekhead;
74 mkv_seekhead *cluster_seekhead;
75 mkv_cues *cues;
76
77 struct AVMD5 *md5_ctx;
78 } MatroskaMuxContext;
79
80
81 /** 2 bytes * 3 for EBML IDs, 3 1-byte EBML lengths, 8 bytes for 64 bit
82 * offset, 4 bytes for target EBML ID */
83 #define MAX_SEEKENTRY_SIZE 21
84
85 /** per-cuepoint-track - 3 1-byte EBML IDs, 3 1-byte EBML sizes, 2
86 * 8-byte uint max */
87 #define MAX_CUETRACKPOS_SIZE 22
88
89 /** per-cuepoint - 2 1-byte EBML IDs, 2 1-byte EBML sizes, 8-byte uint max */
90 #define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
91
92
93 static int ebml_id_size(unsigned int id)
94 {
95 return (av_log2(id+1)-1)/7+1;
96 }
97
98 static void put_ebml_id(ByteIOContext *pb, unsigned int id)
99 {
100 int i = ebml_id_size(id);
101 while (i--)
102 put_byte(pb, id >> (i*8));
103 }
104
105 /**
106 * Write an EBML size meaning "unknown size".
107 *
108 * @param bytes The number of bytes the size should occupy (maximum: 8).
109 */
110 static void put_ebml_size_unknown(ByteIOContext *pb, int bytes)
111 {
112 assert(bytes <= 8);
113 put_byte(pb, 0x1ff >> bytes);
114 while (--bytes)
115 put_byte(pb, 0xff);
116 }
117
118 /**
119 * Calculate how many bytes are needed to represent a given number in EBML.
120 */
121 static int ebml_num_size(uint64_t num)
122 {
123 int bytes = 1;
124 while ((num+1) >> bytes*7) bytes++;
125 return bytes;
126 }
127
128 /**
129 * Write a number in EBML variable length format.
130 *
131 * @param bytes The number of bytes that need to be used to write the number.
132 * If zero, any number of bytes can be used.
133 */
134 static void put_ebml_num(ByteIOContext *pb, uint64_t num, int bytes)
135 {
136 int i, needed_bytes = ebml_num_size(num);
137
138 // sizes larger than this are currently undefined in EBML
139 assert(num < (1ULL<<56)-1);
140
141 if (bytes == 0)
142 // don't care how many bytes are used, so use the min
143 bytes = needed_bytes;
144 // the bytes needed to write the given size would exceed the bytes
145 // that we need to use, so write unknown size. This shouldn't happen.
146 assert(bytes >= needed_bytes);
147
148 num |= 1ULL << bytes*7;
149 for (i = bytes - 1; i >= 0; i--)
150 put_byte(pb, num >> i*8);
151 }
152
153 static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
154 {
155 int i, bytes = 1;
156 uint64_t tmp = val;
157 while (tmp>>=8) bytes++;
158
159 put_ebml_id(pb, elementid);
160 put_ebml_num(pb, bytes, 0);
161 for (i = bytes - 1; i >= 0; i--)
162 put_byte(pb, val >> i*8);
163 }
164
165 static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
166 {
167 put_ebml_id(pb, elementid);
168 put_ebml_num(pb, 8, 0);
169 put_be64(pb, av_dbl2int(val));
170 }
171
172 static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
173 const uint8_t *buf, int size)
174 {
175 put_ebml_id(pb, elementid);
176 put_ebml_num(pb, size, 0);
177 put_buffer(pb, buf, size);
178 }
179
180 static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
181 {
182 put_ebml_binary(pb, elementid, str, strlen(str));
183 }
184
185 /**
186 * Writes a void element of a given size. Useful for reserving space in
187 * the file to be written to later.
188 *
189 * @param size The number of bytes to reserve, which must be at least 2.
190 */
191 static void put_ebml_void(ByteIOContext *pb, uint64_t size)
192 {
193 int64_t currentpos = url_ftell(pb);
194
195 assert(size >= 2);
196
197 put_ebml_id(pb, EBML_ID_VOID);
198 // we need to subtract the length needed to store the size from the
199 // size we need to reserve so 2 cases, we use 8 bytes to store the
200 // size if possible, 1 byte otherwise
201 if (size < 10)
202 put_ebml_num(pb, size-1, 0);
203 else
204 put_ebml_num(pb, size-9, 8);
205 while(url_ftell(pb) < currentpos + size)
206 put_byte(pb, 0);
207 }
208
209 static ebml_master start_ebml_master(ByteIOContext *pb, unsigned int elementid, uint64_t expectedsize)
210 {
211 int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
212 put_ebml_id(pb, elementid);
213 put_ebml_size_unknown(pb, bytes);
214 return (ebml_master){ url_ftell(pb), bytes };
215 }
216
217 static void end_ebml_master(ByteIOContext *pb, ebml_master master)
218 {
219 int64_t pos = url_ftell(pb);
220
221 if (url_fseek(pb, master.pos - master.sizebytes, SEEK_SET) < 0)
222 return;
223 put_ebml_num(pb, pos - master.pos, master.sizebytes);
224 url_fseek(pb, pos, SEEK_SET);
225 }
226
227 static void put_xiph_size(ByteIOContext *pb, int size)
228 {
229 int i;
230 for (i = 0; i < size / 255; i++)
231 put_byte(pb, 255);
232 put_byte(pb, size % 255);
233 }
234
235 /**
236 * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
237 * elements. If a maximum number of elements is specified, enough space
238 * will be reserved at the current file location to write a seek head of
239 * that size.
240 *
241 * @param segment_offset The absolute offset to the position in the file
242 * where the segment begins.
243 * @param numelements The maximum number of elements that will be indexed
244 * by this seek head, 0 if unlimited.
245 */
246 static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, int64_t segment_offset, int numelements)
247 {
248 mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
249 if (new_seekhead == NULL)
250 return NULL;
251
252 new_seekhead->segment_offset = segment_offset;
253
254 if (numelements > 0) {
255 new_seekhead->filepos = url_ftell(pb);
256 // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
257 // and size, and 3 bytes to guarantee that an EBML void element
258 // will fit afterwards
259 new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
260 new_seekhead->max_entries = numelements;
261 put_ebml_void(pb, new_seekhead->reserved_size);
262 }
263 return new_seekhead;
264 }
265
266 static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
267 {
268 mkv_seekhead_entry *entries = seekhead->entries;
269
270 // don't store more elements than we reserved space for
271 if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
272 return -1;
273
274 entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
275 if (entries == NULL)
276 return AVERROR(ENOMEM);
277
278 entries[seekhead->num_entries ].elementid = elementid;
279 entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
280
281 seekhead->entries = entries;
282 return 0;
283 }
284
285 /**
286 * Write the seek head to the file and free it. If a maximum number of
287 * elements was specified to mkv_start_seekhead(), the seek head will
288 * be written at the location reserved for it. Otherwise, it is written
289 * at the current location in the file.
290 *
291 * @return The file offset where the seekhead was written.
292 */
293 static int64_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
294 {
295 ebml_master metaseek, seekentry;
296 int64_t currentpos;
297 int i;
298
299 currentpos = url_ftell(pb);
300
301 if (seekhead->reserved_size > 0)
302 url_fseek(pb, seekhead->filepos, SEEK_SET);
303
304 metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
305 for (i = 0; i < seekhead->num_entries; i++) {
306 mkv_seekhead_entry *entry = &seekhead->entries[i];
307
308 seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
309
310 put_ebml_id(pb, MATROSKA_ID_SEEKID);
311 put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
312 put_ebml_id(pb, entry->elementid);
313
314 put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
315 end_ebml_master(pb, seekentry);
316 }
317 end_ebml_master(pb, metaseek);
318
319 if (seekhead->reserved_size > 0) {
320 uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
321 put_ebml_void(pb, remaining);
322 url_fseek(pb, currentpos, SEEK_SET);
323
324 currentpos = seekhead->filepos;
325 }
326 av_free(seekhead->entries);
327 av_free(seekhead);
328
329 return currentpos;
330 }
331
332 static mkv_cues * mkv_start_cues(int64_t segment_offset)
333 {
334 mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
335 if (cues == NULL)
336 return NULL;
337
338 cues->segment_offset = segment_offset;
339 return cues;
340 }
341
342 static int mkv_add_cuepoint(mkv_cues *cues, AVPacket *pkt, int64_t cluster_pos)
343 {
344 mkv_cuepoint *entries = cues->entries;
345
346 entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
347 if (entries == NULL)
348 return AVERROR(ENOMEM);
349
350 entries[cues->num_entries ].pts = pkt->pts;
351 entries[cues->num_entries ].tracknum = pkt->stream_index + 1;
352 entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
353
354 cues->entries = entries;
355 return 0;
356 }
357
358 static int64_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues, int num_tracks)
359 {
360 ebml_master cues_element;
361 int64_t currentpos;
362 int i, j;
363
364 currentpos = url_ftell(pb);
365 cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
366
367 for (i = 0; i < cues->num_entries; i++) {
368 ebml_master cuepoint, track_positions;
369 mkv_cuepoint *entry = &cues->entries[i];
370 uint64_t pts = entry->pts;
371
372 cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
373 put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
374
375 // put all the entries from different tracks that have the exact same
376 // timestamp into the same CuePoint
377 for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
378 track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
379 put_ebml_uint(pb, MATROSKA_ID_CUETRACK , entry[j].tracknum );
380 put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
381 end_ebml_master(pb, track_positions);
382 }
383 i += j - 1;
384 end_ebml_master(pb, cuepoint);
385 }
386 end_ebml_master(pb, cues_element);
387
388 av_free(cues->entries);
389 av_free(cues);
390 return currentpos;
391 }
392
393 static int put_xiph_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
394 {
395 uint8_t *header_start[3];
396 int header_len[3];
397 int first_header_size;
398 int j;
399
400 if (codec->codec_id == CODEC_ID_VORBIS)
401 first_header_size = 30;
402 else
403 first_header_size = 42;
404
405 if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
406 first_header_size, header_start, header_len) < 0) {
407 av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
408 return -1;
409 }
410
411 put_byte(pb, 2); // number packets - 1
412 for (j = 0; j < 2; j++) {
413 put_xiph_size(pb, header_len[j]);
414 }
415 for (j = 0; j < 3; j++)
416 put_buffer(pb, header_start[j], header_len[j]);
417
418 return 0;
419 }
420
421 static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
422 {
423 int sri;
424
425 if (codec->extradata_size < 2) {
426 av_log(s, AV_LOG_WARNING, "No AAC extradata, unable to determine samplerate.\n");
427 return;
428 }
429
430 sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
431 if (sri > 12) {
432 av_log(s, AV_LOG_WARNING, "AAC samplerate index out of bounds\n");
433 return;
434 }
435 *sample_rate = ff_mpeg4audio_sample_rates[sri];
436
437 // if sbr, get output sample rate as well
438 if (codec->extradata_size == 5) {
439 sri = (codec->extradata[4] >> 3) & 0xF;
440 if (sri > 12) {
441 av_log(s, AV_LOG_WARNING, "AAC output samplerate index out of bounds\n");
442 return;
443 }
444 *output_sample_rate = ff_mpeg4audio_sample_rates[sri];
445 }
446 }
447
448 static int mkv_write_codecprivate(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec, int native_id, int qt_id)
449 {
450 ByteIOContext *dyn_cp;
451 uint8_t *codecpriv;
452 int ret, codecpriv_size;
453
454 ret = url_open_dyn_buf(&dyn_cp);
455 if(ret < 0)
456 return ret;
457
458 if (native_id) {
459 if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA)
460 ret = put_xiph_codecpriv(s, dyn_cp, codec);
461 else if (codec->codec_id == CODEC_ID_FLAC)
462 ret = ff_flac_write_header(dyn_cp, codec);
463 else if (codec->codec_id == CODEC_ID_H264)
464 ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
465 else if (codec->extradata_size)
466 put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
467 } else if (codec->codec_type == CODEC_TYPE_VIDEO) {
468 if (qt_id) {
469 if (!codec->codec_tag)
470 codec->codec_tag = ff_codec_get_tag(codec_movvideo_tags, codec->codec_id);
471 if (codec->extradata_size)
472 put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
473 } else {
474 if (!codec->codec_tag)
475 codec->codec_tag = ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id);
476 if (!codec->codec_tag) {
477 av_log(s, AV_LOG_ERROR, "No bmp codec ID found.");
478 ret = -1;
479 }
480
481 ff_put_bmp_header(dyn_cp, codec, ff_codec_bmp_tags, 0);
482 }
483
484 } else if (codec->codec_type == CODEC_TYPE_AUDIO) {
485 if (!codec->codec_tag)
486 codec->codec_tag = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);
487 if (!codec->codec_tag) {
488 av_log(s, AV_LOG_ERROR, "No wav codec ID found.");
489 ret = -1;
490 }
491
492 ff_put_wav_header(dyn_cp, codec);
493 }
494
495 codecpriv_size = url_close_dyn_buf(dyn_cp, &codecpriv);
496 if (codecpriv_size)
497 put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
498 av_free(codecpriv);
499 return ret;
500 }
501
502 static int mkv_write_tracks(AVFormatContext *s)
503 {
504 MatroskaMuxContext *mkv = s->priv_data;
505 ByteIOContext *pb = s->pb;
506 ebml_master tracks;
507 int i, j, ret;
508
509 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb));
510 if (ret < 0) return ret;
511
512 tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
513 for (i = 0; i < s->nb_streams; i++) {
514 AVStream *st = s->streams[i];
515 AVCodecContext *codec = st->codec;
516 ebml_master subinfo, track;
517 int native_id = 0;
518 int qt_id = 0;
519 int bit_depth = av_get_bits_per_sample(codec->codec_id);
520 int sample_rate = codec->sample_rate;
521 int output_sample_rate = 0;
522 AVMetadataTag *tag;
523
524 if (!bit_depth)
525 bit_depth = av_get_bits_per_sample_format(codec->sample_fmt);
526
527 if (codec->codec_id == CODEC_ID_AAC)
528 get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
529
530 track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
531 put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
532 put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
533 put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
534 put_ebml_float(pb, MATROSKA_ID_TRACKTIMECODESCALE, 1.0);
535
536 if ((tag = av_metadata_get(st->metadata, "title", NULL, 0)))
537 put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
538 tag = av_metadata_get(st->metadata, "language", NULL, 0);
539 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
540
541 if (st->disposition)
542 put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
543
544 // look for a codec ID string specific to mkv to use,
545 // if none are found, use AVI codes
546 for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
547 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
548 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
549 native_id = 1;
550 break;
551 }
552 }
553
554 switch (codec->codec_type) {
555 case CODEC_TYPE_VIDEO:
556 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
557
558 if (!native_id &&
559 ff_codec_get_tag(codec_movvideo_tags, codec->codec_id) &&
560 (!ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id)
561 || codec->codec_id == CODEC_ID_SVQ1
562 || codec->codec_id == CODEC_ID_SVQ3
563 || codec->codec_id == CODEC_ID_CINEPAK))
564 qt_id = 1;
565
566 if (qt_id)
567 put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
568 else if (!native_id)
569 // if there is no mkv-specific codec ID, use VFW mode
570 put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
571
572 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
573 // XXX: interlace flag?
574 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
575 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
576 if (st->sample_aspect_ratio.num) {
577 int d_width = codec->width*av_q2d(st->sample_aspect_ratio);
578 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width);
579 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height);
580 }
581 end_ebml_master(pb, subinfo);
582 break;
583
584 case CODEC_TYPE_AUDIO:
585 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
586
587 if (!native_id)
588 // no mkv-specific ID, use ACM mode
589 put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
590
591 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
592 put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
593 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
594 if (output_sample_rate)
595 put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
596 if (bit_depth)
597 put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
598 end_ebml_master(pb, subinfo);
599 break;
600
601 case CODEC_TYPE_SUBTITLE:
602 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
603 break;
604 default:
605 av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.");
606 break;
607 }
608 ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
609 if (ret < 0) return ret;
610
611 end_ebml_master(pb, track);
612
613 // ms precision is the de-facto standard timescale for mkv files
614 av_set_pts_info(st, 64, 1, 1000);
615 }
616 end_ebml_master(pb, tracks);
617 return 0;
618 }
619
620 static int mkv_write_chapters(AVFormatContext *s)
621 {
622 MatroskaMuxContext *mkv = s->priv_data;
623 ByteIOContext *pb = s->pb;
624 ebml_master chapters, editionentry;
625 AVRational scale = {1, 1E9};
626 int i, ret;
627
628 if (!s->nb_chapters)
629 return 0;
630
631 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CHAPTERS, url_ftell(pb));
632 if (ret < 0) return ret;
633
634 chapters = start_ebml_master(pb, MATROSKA_ID_CHAPTERS , 0);
635 editionentry = start_ebml_master(pb, MATROSKA_ID_EDITIONENTRY, 0);
636 put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGDEFAULT, 1);
637 put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGHIDDEN , 0);
638 for (i = 0; i < s->nb_chapters; i++) {
639 ebml_master chapteratom, chapterdisplay;
640 AVChapter *c = s->chapters[i];
641 AVMetadataTag *t = NULL;
642
643 chapteratom = start_ebml_master(pb, MATROSKA_ID_CHAPTERATOM, 0);
644 put_ebml_uint(pb, MATROSKA_ID_CHAPTERUID, c->id);
645 put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMESTART,
646 av_rescale_q(c->start, c->time_base, scale));
647 put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMEEND,
648 av_rescale_q(c->end, c->time_base, scale));
649 put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGHIDDEN , 0);
650 put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGENABLED, 1);
651 if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {
652 chapterdisplay = start_ebml_master(pb, MATROSKA_ID_CHAPTERDISPLAY, 0);
653 put_ebml_string(pb, MATROSKA_ID_CHAPSTRING, t->value);
654 put_ebml_string(pb, MATROSKA_ID_CHAPLANG , "und");
655 end_ebml_master(pb, chapterdisplay);
656 }
657 end_ebml_master(pb, chapteratom);
658 }
659 end_ebml_master(pb, editionentry);
660 end_ebml_master(pb, chapters);
661 return 0;
662 }
663
664 static int mkv_write_header(AVFormatContext *s)
665 {
666 MatroskaMuxContext *mkv = s->priv_data;
667 ByteIOContext *pb = s->pb;
668 ebml_master ebml_header, segment_info;
669 AVMetadataTag *tag;
670 int ret;
671
672 mkv->md5_ctx = av_mallocz(av_md5_size);
673 av_md5_init(mkv->md5_ctx);
674
675 ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
676 put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
677 put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
678 put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
679 put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
680 put_ebml_string (pb, EBML_ID_DOCTYPE , "matroska");
681 put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2);
682 put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2);
683 end_ebml_master(pb, ebml_header);
684
685 mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
686 mkv->segment_offset = url_ftell(pb);
687
688 // we write 2 seek heads - one at the end of the file to point to each
689 // cluster, and one at the beginning to point to all other level one
690 // elements (including the seek head at the end of the file), which
691 // isn't more than 10 elements if we only write one of each other
692 // currently defined level 1 element
693 mkv->main_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 10);
694 mkv->cluster_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 0);
695 if (mkv->main_seekhead == NULL || mkv->cluster_seekhead == NULL)
696 return AVERROR(ENOMEM);
697
698 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb));
699 if (ret < 0) return ret;
700
701 segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
702 put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
703 if ((tag = av_metadata_get(s->metadata, "title", NULL, 0)))
704 put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
705 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
706 put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
707 put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
708
709 // reserve space to write the segment UID later
710 mkv->segment_uid = url_ftell(pb);
711 put_ebml_void(pb, 19);
712 }
713
714 // reserve space for the duration
715 mkv->duration = 0;
716 mkv->duration_offset = url_ftell(pb);
717 put_ebml_void(pb, 11); // assumes double-precision float to be written
718 end_ebml_master(pb, segment_info);
719
720 ret = mkv_write_tracks(s);
721 if (ret < 0) return ret;
722
723 ret = mkv_write_chapters(s);
724 if (ret < 0) return ret;
725
726 ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
727 if (ret < 0) return ret;
728
729 mkv->cluster_pos = url_ftell(pb);
730 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
731 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0);
732 mkv->cluster_pts = 0;
733
734 mkv->cues = mkv_start_cues(mkv->segment_offset);
735 if (mkv->cues == NULL)
736 return AVERROR(ENOMEM);
737
738 put_flush_packet(pb);
739 return 0;
740 }
741
742 static int mkv_blockgroup_size(int pkt_size)
743 {
744 int size = pkt_size + 4;
745 size += ebml_num_size(size);
746 size += 2; // EBML ID for block and block duration
747 size += 8; // max size of block duration
748 size += ebml_num_size(size);
749 size += 1; // blockgroup EBML ID
750 return size;
751 }
752
753 static int ass_get_duration(const uint8_t *p)
754 {
755 int sh, sm, ss, sc, eh, em, es, ec;
756 uint64_t start, end;
757
758 if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
759 &sh, &sm, &ss, &sc, &eh, &em, &es, &ec) != 8)
760 return 0;
761 start = 3600000*sh + 60000*sm + 1000*ss + 10*sc;
762 end = 3600000*eh + 60000*em + 1000*es + 10*ec;
763 return end - start;
764 }
765
766 static int mkv_write_ass_blocks(AVFormatContext *s, AVPacket *pkt)
767 {
768 MatroskaMuxContext *mkv = s->priv_data;
769 ByteIOContext *pb = s->pb;
770 int i, layer = 0, max_duration = 0, size, line_size, data_size = pkt->size;
771 uint8_t *start, *end, *data = pkt->data;
772 ebml_master blockgroup;
773 char buffer[2048];
774
775 while (data_size) {
776 int duration = ass_get_duration(data);
777 max_duration = FFMAX(duration, max_duration);
778 end = memchr(data, '\n', data_size);
779 size = line_size = end ? end-data+1 : data_size;
780 size -= end ? (end[-1]=='\r')+1 : 0;
781 start = data;
782 for (i=0; i<3; i++, start++)
783 if (!(start = memchr(start, ',', size-(start-data))))
784 return max_duration;
785 size -= start - data;
786 sscanf(data, "Dialogue: %d,", &layer);
787 i = snprintf(buffer, sizeof(buffer), "%"PRId64",%d,",
788 s->streams[pkt->stream_index]->nb_frames++, layer);
789 size = FFMIN(i+size, sizeof(buffer));
790 memcpy(buffer+i, start, size-i);
791
792 av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
793 "pts %" PRId64 ", duration %d\n",
794 url_ftell(pb), size, pkt->pts, duration);
795 blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
796 put_ebml_id(pb, MATROSKA_ID_BLOCK);
797 put_ebml_num(pb, size+4, 0);
798 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
799 put_be16(pb, pkt->pts - mkv->cluster_pts);
800 put_byte(pb, 0);
801 put_buffer(pb, buffer, size);
802 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
803 end_ebml_master(pb, blockgroup);
804
805 data += line_size;
806 data_size -= line_size;
807 }
808
809 return max_duration;
810 }
811
812 static void mkv_write_block(AVFormatContext *s, unsigned int blockid, AVPacket *pkt, int flags)
813 {
814 MatroskaMuxContext *mkv = s->priv_data;
815 ByteIOContext *pb = s->pb;
816 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
817 uint8_t *data = NULL;
818 int size = pkt->size;
819
820 av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
821 "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
822 url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
823 if (codec->codec_id == CODEC_ID_H264 && codec->extradata_size > 0 &&
824 (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
825 ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
826 else
827 data = pkt->data;
828 put_ebml_id(pb, blockid);
829 put_ebml_num(pb, size+4, 0);
830 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
831 put_be16(pb, pkt->pts - mkv->cluster_pts);
832 put_byte(pb, flags);
833 put_buffer(pb, data, size);
834 if (data != pkt->data)
835 av_free(data);
836 }
837
838 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
839 {
840 MatroskaMuxContext *mkv = s->priv_data;
841 ByteIOContext *pb = s->pb;
842 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
843 int keyframe = !!(pkt->flags & PKT_FLAG_KEY);
844 int duration = pkt->duration;
845 int ret;
846
847 // start a new cluster every 5 MB or 5 sec
848 if (url_ftell(pb) > mkv->cluster_pos + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) {
849 av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
850 " bytes, pts %" PRIu64 "\n", url_ftell(pb), pkt->pts);
851 end_ebml_master(pb, mkv->cluster);
852
853 ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
854 if (ret < 0) return ret;
855
856 mkv->cluster_pos = url_ftell(pb);
857 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
858 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts);
859 mkv->cluster_pts = pkt->pts;
860 av_md5_update(mkv->md5_ctx, pkt->data, FFMIN(200, pkt->size));
861 }
862
863 if (codec->codec_type != CODEC_TYPE_SUBTITLE) {
864 mkv_write_block(s, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
865 } else if (codec->codec_id == CODEC_ID_SSA) {
866 duration = mkv_write_ass_blocks(s, pkt);
867 } else {
868 ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
869 duration = pkt->convergence_duration;
870 mkv_write_block(s, MATROSKA_ID_BLOCK, pkt, 0);
871 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
872 end_ebml_master(pb, blockgroup);
873 }
874
875 if (codec->codec_type == CODEC_TYPE_VIDEO && keyframe) {
876 ret = mkv_add_cuepoint(mkv->cues, pkt, mkv->cluster_pos);
877 if (ret < 0) return ret;
878 }
879
880 mkv->duration = FFMAX(mkv->duration, pkt->pts + duration);
881 return 0;
882 }
883
884 static int mkv_write_trailer(AVFormatContext *s)
885 {
886 MatroskaMuxContext *mkv = s->priv_data;
887 ByteIOContext *pb = s->pb;
888 int64_t currentpos, second_seekhead, cuespos;
889 int ret;
890
891 end_ebml_master(pb, mkv->cluster);
892
893 if (!url_is_streamed(pb)) {
894 cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
895 second_seekhead = mkv_write_seekhead(pb, mkv->cluster_seekhead);
896
897 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES , cuespos);
898 if (ret < 0) return ret;
899 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_SEEKHEAD, second_seekhead);
900 if (ret < 0) return ret;
901 mkv_write_seekhead(pb, mkv->main_seekhead);
902
903 // update the duration
904 av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
905 currentpos = url_ftell(pb);
906 url_fseek(pb, mkv->duration_offset, SEEK_SET);
907 put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
908
909 // write the md5sum of some frames as the segment UID
910 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
911 uint8_t segment_uid[16];
912 av_md5_final(mkv->md5_ctx, segment_uid);
913 url_fseek(pb, mkv->segment_uid, SEEK_SET);
914 put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
915 }
916 url_fseek(pb, currentpos, SEEK_SET);
917 }
918
919 end_ebml_master(pb, mkv->segment);
920 av_free(mkv->md5_ctx);
921 put_flush_packet(pb);
922 return 0;
923 }
924
925 AVOutputFormat matroska_muxer = {
926 "matroska",
927 NULL_IF_CONFIG_SMALL("Matroska file format"),
928 "video/x-matroska",
929 "mkv",
930 sizeof(MatroskaMuxContext),
931 CODEC_ID_MP2,
932 CODEC_ID_MPEG4,
933 mkv_write_header,
934 mkv_write_packet,
935 mkv_write_trailer,
936 .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
937 .codec_tag = (const AVCodecTag* const []){ff_codec_bmp_tags, ff_codec_wav_tags, 0},
938 .subtitle_codec = CODEC_ID_TEXT,
939 };
940
941 AVOutputFormat matroska_audio_muxer = {
942 "matroska",
943 NULL_IF_CONFIG_SMALL("Matroska file format"),
944 "audio/x-matroska",
945 "mka",
946 sizeof(MatroskaMuxContext),
947 CODEC_ID_MP2,
948 CODEC_ID_NONE,
949 mkv_write_header,
950 mkv_write_packet,
951 mkv_write_trailer,
952 .flags = AVFMT_GLOBALHEADER,
953 .codec_tag = (const AVCodecTag* const []){ff_codec_wav_tags, 0},
954 };