Write the first seekhead if writing to a stream, we won't be able to seek
[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 * -1 if an error occurred.
293 */
294 static int64_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
295 {
296 ebml_master metaseek, seekentry;
297 int64_t currentpos;
298 int i;
299
300 currentpos = url_ftell(pb);
301
302 if (seekhead->reserved_size > 0)
303 if (url_fseek(pb, seekhead->filepos, SEEK_SET) < 0)
304 return -1;
305
306 metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
307 for (i = 0; i < seekhead->num_entries; i++) {
308 mkv_seekhead_entry *entry = &seekhead->entries[i];
309
310 seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
311
312 put_ebml_id(pb, MATROSKA_ID_SEEKID);
313 put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
314 put_ebml_id(pb, entry->elementid);
315
316 put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
317 end_ebml_master(pb, seekentry);
318 }
319 end_ebml_master(pb, metaseek);
320
321 if (seekhead->reserved_size > 0) {
322 uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
323 put_ebml_void(pb, remaining);
324 url_fseek(pb, currentpos, SEEK_SET);
325
326 currentpos = seekhead->filepos;
327 }
328 av_free(seekhead->entries);
329 av_free(seekhead);
330
331 return currentpos;
332 }
333
334 static mkv_cues * mkv_start_cues(int64_t segment_offset)
335 {
336 mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
337 if (cues == NULL)
338 return NULL;
339
340 cues->segment_offset = segment_offset;
341 return cues;
342 }
343
344 static int mkv_add_cuepoint(mkv_cues *cues, AVPacket *pkt, int64_t cluster_pos)
345 {
346 mkv_cuepoint *entries = cues->entries;
347
348 entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
349 if (entries == NULL)
350 return AVERROR(ENOMEM);
351
352 entries[cues->num_entries ].pts = pkt->pts;
353 entries[cues->num_entries ].tracknum = pkt->stream_index + 1;
354 entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
355
356 cues->entries = entries;
357 return 0;
358 }
359
360 static int64_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues, int num_tracks)
361 {
362 ebml_master cues_element;
363 int64_t currentpos;
364 int i, j;
365
366 currentpos = url_ftell(pb);
367 cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
368
369 for (i = 0; i < cues->num_entries; i++) {
370 ebml_master cuepoint, track_positions;
371 mkv_cuepoint *entry = &cues->entries[i];
372 uint64_t pts = entry->pts;
373
374 cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
375 put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
376
377 // put all the entries from different tracks that have the exact same
378 // timestamp into the same CuePoint
379 for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
380 track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
381 put_ebml_uint(pb, MATROSKA_ID_CUETRACK , entry[j].tracknum );
382 put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
383 end_ebml_master(pb, track_positions);
384 }
385 i += j - 1;
386 end_ebml_master(pb, cuepoint);
387 }
388 end_ebml_master(pb, cues_element);
389
390 av_free(cues->entries);
391 av_free(cues);
392 return currentpos;
393 }
394
395 static int put_xiph_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
396 {
397 uint8_t *header_start[3];
398 int header_len[3];
399 int first_header_size;
400 int j;
401
402 if (codec->codec_id == CODEC_ID_VORBIS)
403 first_header_size = 30;
404 else
405 first_header_size = 42;
406
407 if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
408 first_header_size, header_start, header_len) < 0) {
409 av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
410 return -1;
411 }
412
413 put_byte(pb, 2); // number packets - 1
414 for (j = 0; j < 2; j++) {
415 put_xiph_size(pb, header_len[j]);
416 }
417 for (j = 0; j < 3; j++)
418 put_buffer(pb, header_start[j], header_len[j]);
419
420 return 0;
421 }
422
423 static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
424 {
425 int sri;
426
427 if (codec->extradata_size < 2) {
428 av_log(s, AV_LOG_WARNING, "No AAC extradata, unable to determine samplerate.\n");
429 return;
430 }
431
432 sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
433 if (sri > 12) {
434 av_log(s, AV_LOG_WARNING, "AAC samplerate index out of bounds\n");
435 return;
436 }
437 *sample_rate = ff_mpeg4audio_sample_rates[sri];
438
439 // if sbr, get output sample rate as well
440 if (codec->extradata_size == 5) {
441 sri = (codec->extradata[4] >> 3) & 0xF;
442 if (sri > 12) {
443 av_log(s, AV_LOG_WARNING, "AAC output samplerate index out of bounds\n");
444 return;
445 }
446 *output_sample_rate = ff_mpeg4audio_sample_rates[sri];
447 }
448 }
449
450 static int mkv_write_codecprivate(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec, int native_id, int qt_id)
451 {
452 ByteIOContext *dyn_cp;
453 uint8_t *codecpriv;
454 int ret, codecpriv_size;
455
456 ret = url_open_dyn_buf(&dyn_cp);
457 if(ret < 0)
458 return ret;
459
460 if (native_id) {
461 if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA)
462 ret = put_xiph_codecpriv(s, dyn_cp, codec);
463 else if (codec->codec_id == CODEC_ID_FLAC)
464 ret = ff_flac_write_header(dyn_cp, codec);
465 else if (codec->codec_id == CODEC_ID_H264)
466 ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
467 else if (codec->extradata_size)
468 put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
469 } else if (codec->codec_type == CODEC_TYPE_VIDEO) {
470 if (qt_id) {
471 if (!codec->codec_tag)
472 codec->codec_tag = ff_codec_get_tag(codec_movvideo_tags, codec->codec_id);
473 if (codec->extradata_size)
474 put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
475 } else {
476 if (!codec->codec_tag)
477 codec->codec_tag = ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id);
478 if (!codec->codec_tag) {
479 av_log(s, AV_LOG_ERROR, "No bmp codec ID found.");
480 ret = -1;
481 }
482
483 ff_put_bmp_header(dyn_cp, codec, ff_codec_bmp_tags, 0);
484 }
485
486 } else if (codec->codec_type == CODEC_TYPE_AUDIO) {
487 if (!codec->codec_tag)
488 codec->codec_tag = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);
489 if (!codec->codec_tag) {
490 av_log(s, AV_LOG_ERROR, "No wav codec ID found.");
491 ret = -1;
492 }
493
494 ff_put_wav_header(dyn_cp, codec);
495 }
496
497 codecpriv_size = url_close_dyn_buf(dyn_cp, &codecpriv);
498 if (codecpriv_size)
499 put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
500 av_free(codecpriv);
501 return ret;
502 }
503
504 static int mkv_write_tracks(AVFormatContext *s)
505 {
506 MatroskaMuxContext *mkv = s->priv_data;
507 ByteIOContext *pb = s->pb;
508 ebml_master tracks;
509 int i, j, ret;
510
511 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb));
512 if (ret < 0) return ret;
513
514 tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
515 for (i = 0; i < s->nb_streams; i++) {
516 AVStream *st = s->streams[i];
517 AVCodecContext *codec = st->codec;
518 ebml_master subinfo, track;
519 int native_id = 0;
520 int qt_id = 0;
521 int bit_depth = av_get_bits_per_sample(codec->codec_id);
522 int sample_rate = codec->sample_rate;
523 int output_sample_rate = 0;
524 AVMetadataTag *tag;
525
526 if (!bit_depth)
527 bit_depth = av_get_bits_per_sample_format(codec->sample_fmt);
528
529 if (codec->codec_id == CODEC_ID_AAC)
530 get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
531
532 track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
533 put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
534 put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
535 put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
536 put_ebml_float(pb, MATROSKA_ID_TRACKTIMECODESCALE, 1.0);
537
538 if ((tag = av_metadata_get(st->metadata, "title", NULL, 0)))
539 put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
540 tag = av_metadata_get(st->metadata, "language", NULL, 0);
541 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
542
543 if (st->disposition)
544 put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
545
546 // look for a codec ID string specific to mkv to use,
547 // if none are found, use AVI codes
548 for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
549 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
550 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
551 native_id = 1;
552 break;
553 }
554 }
555
556 switch (codec->codec_type) {
557 case CODEC_TYPE_VIDEO:
558 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
559
560 if (!native_id &&
561 ff_codec_get_tag(codec_movvideo_tags, codec->codec_id) &&
562 (!ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id)
563 || codec->codec_id == CODEC_ID_SVQ1
564 || codec->codec_id == CODEC_ID_SVQ3
565 || codec->codec_id == CODEC_ID_CINEPAK))
566 qt_id = 1;
567
568 if (qt_id)
569 put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
570 else if (!native_id)
571 // if there is no mkv-specific codec ID, use VFW mode
572 put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
573
574 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
575 // XXX: interlace flag?
576 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
577 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
578 if (st->sample_aspect_ratio.num) {
579 int d_width = codec->width*av_q2d(st->sample_aspect_ratio);
580 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width);
581 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height);
582 }
583 end_ebml_master(pb, subinfo);
584 break;
585
586 case CODEC_TYPE_AUDIO:
587 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
588
589 if (!native_id)
590 // no mkv-specific ID, use ACM mode
591 put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
592
593 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
594 put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
595 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
596 if (output_sample_rate)
597 put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
598 if (bit_depth)
599 put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
600 end_ebml_master(pb, subinfo);
601 break;
602
603 case CODEC_TYPE_SUBTITLE:
604 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
605 break;
606 default:
607 av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.");
608 break;
609 }
610 ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
611 if (ret < 0) return ret;
612
613 end_ebml_master(pb, track);
614
615 // ms precision is the de-facto standard timescale for mkv files
616 av_set_pts_info(st, 64, 1, 1000);
617 }
618 end_ebml_master(pb, tracks);
619 return 0;
620 }
621
622 static int mkv_write_chapters(AVFormatContext *s)
623 {
624 MatroskaMuxContext *mkv = s->priv_data;
625 ByteIOContext *pb = s->pb;
626 ebml_master chapters, editionentry;
627 AVRational scale = {1, 1E9};
628 int i, ret;
629
630 if (!s->nb_chapters)
631 return 0;
632
633 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CHAPTERS, url_ftell(pb));
634 if (ret < 0) return ret;
635
636 chapters = start_ebml_master(pb, MATROSKA_ID_CHAPTERS , 0);
637 editionentry = start_ebml_master(pb, MATROSKA_ID_EDITIONENTRY, 0);
638 put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGDEFAULT, 1);
639 put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGHIDDEN , 0);
640 for (i = 0; i < s->nb_chapters; i++) {
641 ebml_master chapteratom, chapterdisplay;
642 AVChapter *c = s->chapters[i];
643 AVMetadataTag *t = NULL;
644
645 chapteratom = start_ebml_master(pb, MATROSKA_ID_CHAPTERATOM, 0);
646 put_ebml_uint(pb, MATROSKA_ID_CHAPTERUID, c->id);
647 put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMESTART,
648 av_rescale_q(c->start, c->time_base, scale));
649 put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMEEND,
650 av_rescale_q(c->end, c->time_base, scale));
651 put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGHIDDEN , 0);
652 put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGENABLED, 1);
653 if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {
654 chapterdisplay = start_ebml_master(pb, MATROSKA_ID_CHAPTERDISPLAY, 0);
655 put_ebml_string(pb, MATROSKA_ID_CHAPSTRING, t->value);
656 put_ebml_string(pb, MATROSKA_ID_CHAPLANG , "und");
657 end_ebml_master(pb, chapterdisplay);
658 }
659 end_ebml_master(pb, chapteratom);
660 }
661 end_ebml_master(pb, editionentry);
662 end_ebml_master(pb, chapters);
663 return 0;
664 }
665
666 static int mkv_write_header(AVFormatContext *s)
667 {
668 MatroskaMuxContext *mkv = s->priv_data;
669 ByteIOContext *pb = s->pb;
670 ebml_master ebml_header, segment_info;
671 AVMetadataTag *tag;
672 int ret;
673
674 mkv->md5_ctx = av_mallocz(av_md5_size);
675 av_md5_init(mkv->md5_ctx);
676
677 ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
678 put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
679 put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
680 put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
681 put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
682 put_ebml_string (pb, EBML_ID_DOCTYPE , "matroska");
683 put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2);
684 put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2);
685 end_ebml_master(pb, ebml_header);
686
687 mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
688 mkv->segment_offset = url_ftell(pb);
689
690 // we write 2 seek heads - one at the end of the file to point to each
691 // cluster, and one at the beginning to point to all other level one
692 // elements (including the seek head at the end of the file), which
693 // isn't more than 10 elements if we only write one of each other
694 // currently defined level 1 element
695 mkv->main_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 10);
696 mkv->cluster_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 0);
697 if (mkv->main_seekhead == NULL || mkv->cluster_seekhead == NULL)
698 return AVERROR(ENOMEM);
699
700 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb));
701 if (ret < 0) return ret;
702
703 segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
704 put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
705 if ((tag = av_metadata_get(s->metadata, "title", NULL, 0)))
706 put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
707 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
708 put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
709 put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
710
711 // reserve space to write the segment UID later
712 mkv->segment_uid = url_ftell(pb);
713 put_ebml_void(pb, 19);
714 }
715
716 // reserve space for the duration
717 mkv->duration = 0;
718 mkv->duration_offset = url_ftell(pb);
719 put_ebml_void(pb, 11); // assumes double-precision float to be written
720 end_ebml_master(pb, segment_info);
721
722 ret = mkv_write_tracks(s);
723 if (ret < 0) return ret;
724
725 ret = mkv_write_chapters(s);
726 if (ret < 0) return ret;
727
728 ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
729 if (ret < 0) return ret;
730
731 mkv->cluster_pos = url_ftell(pb);
732 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
733 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0);
734 mkv->cluster_pts = 0;
735
736 if (url_is_streamed(s->pb))
737 mkv_write_seekhead(pb, mkv->main_seekhead);
738
739 mkv->cues = mkv_start_cues(mkv->segment_offset);
740 if (mkv->cues == NULL)
741 return AVERROR(ENOMEM);
742
743 put_flush_packet(pb);
744 return 0;
745 }
746
747 static int mkv_blockgroup_size(int pkt_size)
748 {
749 int size = pkt_size + 4;
750 size += ebml_num_size(size);
751 size += 2; // EBML ID for block and block duration
752 size += 8; // max size of block duration
753 size += ebml_num_size(size);
754 size += 1; // blockgroup EBML ID
755 return size;
756 }
757
758 static int ass_get_duration(const uint8_t *p)
759 {
760 int sh, sm, ss, sc, eh, em, es, ec;
761 uint64_t start, end;
762
763 if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
764 &sh, &sm, &ss, &sc, &eh, &em, &es, &ec) != 8)
765 return 0;
766 start = 3600000*sh + 60000*sm + 1000*ss + 10*sc;
767 end = 3600000*eh + 60000*em + 1000*es + 10*ec;
768 return end - start;
769 }
770
771 static int mkv_write_ass_blocks(AVFormatContext *s, AVPacket *pkt)
772 {
773 MatroskaMuxContext *mkv = s->priv_data;
774 ByteIOContext *pb = s->pb;
775 int i, layer = 0, max_duration = 0, size, line_size, data_size = pkt->size;
776 uint8_t *start, *end, *data = pkt->data;
777 ebml_master blockgroup;
778 char buffer[2048];
779
780 while (data_size) {
781 int duration = ass_get_duration(data);
782 max_duration = FFMAX(duration, max_duration);
783 end = memchr(data, '\n', data_size);
784 size = line_size = end ? end-data+1 : data_size;
785 size -= end ? (end[-1]=='\r')+1 : 0;
786 start = data;
787 for (i=0; i<3; i++, start++)
788 if (!(start = memchr(start, ',', size-(start-data))))
789 return max_duration;
790 size -= start - data;
791 sscanf(data, "Dialogue: %d,", &layer);
792 i = snprintf(buffer, sizeof(buffer), "%"PRId64",%d,",
793 s->streams[pkt->stream_index]->nb_frames++, layer);
794 size = FFMIN(i+size, sizeof(buffer));
795 memcpy(buffer+i, start, size-i);
796
797 av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
798 "pts %" PRId64 ", duration %d\n",
799 url_ftell(pb), size, pkt->pts, duration);
800 blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
801 put_ebml_id(pb, MATROSKA_ID_BLOCK);
802 put_ebml_num(pb, size+4, 0);
803 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
804 put_be16(pb, pkt->pts - mkv->cluster_pts);
805 put_byte(pb, 0);
806 put_buffer(pb, buffer, size);
807 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
808 end_ebml_master(pb, blockgroup);
809
810 data += line_size;
811 data_size -= line_size;
812 }
813
814 return max_duration;
815 }
816
817 static void mkv_write_block(AVFormatContext *s, unsigned int blockid, AVPacket *pkt, int flags)
818 {
819 MatroskaMuxContext *mkv = s->priv_data;
820 ByteIOContext *pb = s->pb;
821 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
822 uint8_t *data = NULL;
823 int size = pkt->size;
824
825 av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
826 "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
827 url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
828 if (codec->codec_id == CODEC_ID_H264 && codec->extradata_size > 0 &&
829 (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
830 ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
831 else
832 data = pkt->data;
833 put_ebml_id(pb, blockid);
834 put_ebml_num(pb, size+4, 0);
835 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
836 put_be16(pb, pkt->pts - mkv->cluster_pts);
837 put_byte(pb, flags);
838 put_buffer(pb, data, size);
839 if (data != pkt->data)
840 av_free(data);
841 }
842
843 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
844 {
845 MatroskaMuxContext *mkv = s->priv_data;
846 ByteIOContext *pb = s->pb;
847 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
848 int keyframe = !!(pkt->flags & PKT_FLAG_KEY);
849 int duration = pkt->duration;
850 int ret;
851
852 // start a new cluster every 5 MB or 5 sec
853 if (url_ftell(pb) > mkv->cluster_pos + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) {
854 av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
855 " bytes, pts %" PRIu64 "\n", url_ftell(pb), pkt->pts);
856 end_ebml_master(pb, mkv->cluster);
857
858 ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
859 if (ret < 0) return ret;
860
861 mkv->cluster_pos = url_ftell(pb);
862 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
863 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts);
864 mkv->cluster_pts = pkt->pts;
865 av_md5_update(mkv->md5_ctx, pkt->data, FFMIN(200, pkt->size));
866 }
867
868 if (codec->codec_type != CODEC_TYPE_SUBTITLE) {
869 mkv_write_block(s, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
870 } else if (codec->codec_id == CODEC_ID_SSA) {
871 duration = mkv_write_ass_blocks(s, pkt);
872 } else {
873 ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
874 duration = pkt->convergence_duration;
875 mkv_write_block(s, MATROSKA_ID_BLOCK, pkt, 0);
876 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
877 end_ebml_master(pb, blockgroup);
878 }
879
880 if (codec->codec_type == CODEC_TYPE_VIDEO && keyframe) {
881 ret = mkv_add_cuepoint(mkv->cues, pkt, mkv->cluster_pos);
882 if (ret < 0) return ret;
883 }
884
885 mkv->duration = FFMAX(mkv->duration, pkt->pts + duration);
886 return 0;
887 }
888
889 static int mkv_write_trailer(AVFormatContext *s)
890 {
891 MatroskaMuxContext *mkv = s->priv_data;
892 ByteIOContext *pb = s->pb;
893 int64_t currentpos, second_seekhead, cuespos;
894 int ret;
895
896 end_ebml_master(pb, mkv->cluster);
897
898 if (!url_is_streamed(pb)) {
899 cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
900 second_seekhead = mkv_write_seekhead(pb, mkv->cluster_seekhead);
901
902 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES , cuespos);
903 if (ret < 0) return ret;
904 if (second_seekhead >= 0) {
905 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_SEEKHEAD, second_seekhead);
906 if (ret < 0) return ret;
907 }
908 mkv_write_seekhead(pb, mkv->main_seekhead);
909
910 // update the duration
911 av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
912 currentpos = url_ftell(pb);
913 url_fseek(pb, mkv->duration_offset, SEEK_SET);
914 put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
915
916 // write the md5sum of some frames as the segment UID
917 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
918 uint8_t segment_uid[16];
919 av_md5_final(mkv->md5_ctx, segment_uid);
920 url_fseek(pb, mkv->segment_uid, SEEK_SET);
921 put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
922 }
923 url_fseek(pb, currentpos, SEEK_SET);
924 }
925
926 end_ebml_master(pb, mkv->segment);
927 av_free(mkv->md5_ctx);
928 put_flush_packet(pb);
929 return 0;
930 }
931
932 AVOutputFormat matroska_muxer = {
933 "matroska",
934 NULL_IF_CONFIG_SMALL("Matroska file format"),
935 "video/x-matroska",
936 "mkv",
937 sizeof(MatroskaMuxContext),
938 CODEC_ID_MP2,
939 CODEC_ID_MPEG4,
940 mkv_write_header,
941 mkv_write_packet,
942 mkv_write_trailer,
943 .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
944 .codec_tag = (const AVCodecTag* const []){ff_codec_bmp_tags, ff_codec_wav_tags, 0},
945 .subtitle_codec = CODEC_ID_TEXT,
946 };
947
948 AVOutputFormat matroska_audio_muxer = {
949 "matroska",
950 NULL_IF_CONFIG_SMALL("Matroska file format"),
951 "audio/x-matroska",
952 "mka",
953 sizeof(MatroskaMuxContext),
954 CODEC_ID_MP2,
955 CODEC_ID_NONE,
956 mkv_write_header,
957 mkv_write_packet,
958 mkv_write_trailer,
959 .flags = AVFMT_GLOBALHEADER,
960 .codec_tag = (const AVCodecTag* const []){ff_codec_wav_tags, 0},
961 };