3 * Copyright (c) 2007 David Conrad
5 * This file is part of FFmpeg.
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.
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.
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
28 typedef struct mkv_seekhead_entry {
29 unsigned int elementid;
33 typedef struct mkv_seekhead {
35 offset_t segment_offset; ///< the file offset to the beginning of the segment
36 int reserved_size; ///< -1 if appending to file
38 mkv_seekhead_entry *entries;
45 offset_t cluster_pos; ///< file offset of the cluster containing the block
49 offset_t segment_offset;
50 mkv_cuepoint *entries;
54 typedef struct MatroskaMuxContext {
56 offset_t segment_offset;
59 offset_t cluster_pos; ///< file offset of the current cluster
61 offset_t duration_offset;
63 mkv_seekhead *main_seekhead;
64 mkv_seekhead *cluster_seekhead;
67 struct AVMD5 *md5_ctx;
70 static int ebml_id_size(unsigned int id)
72 return (av_log2(id+1)-1)/7+1;
75 static void put_ebml_id(ByteIOContext *pb, unsigned int id)
77 int i = ebml_id_size(id);
79 put_byte(pb, id >> (i*8));
83 * Write an EBML size meaning "unknown size"
85 * @param bytes The number of bytes the size should occupy. Maximum of 8.
87 static void put_ebml_size_unknown(ByteIOContext *pb, int bytes)
92 bytes = FFMIN(bytes, 8);
93 for (i = 0; i < bytes*7 + 1; i++)
95 for (i = bytes-1; i >= 0; i--)
96 put_byte(pb, value >> i*8);
99 // XXX: test this thoroughly and get rid of minbytes hack (currently needed to
100 // use up all of the space reserved in start_ebml_master)
101 static void put_ebml_size(ByteIOContext *pb, uint64_t size, int minbytes)
103 int i, bytes = minbytes;
105 // sizes larger than this are currently undefined in EBML
106 // so write "unknown" size
107 if (size >= (1ULL<<56)-1) {
108 put_ebml_size_unknown(pb, 1);
112 while ((size+1) >> bytes*7) bytes++;
114 put_byte(pb, (0x80 >> (bytes-1)) | (size >> (bytes-1)*8));
115 for (i = bytes - 2; i >= 0; i--)
116 put_byte(pb, size >> i*8);
119 static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
122 while (val >> bytes*8) bytes++;
124 put_ebml_id(pb, elementid);
125 put_ebml_size(pb, bytes, 0);
126 for (i = bytes - 1; i >= 0; i--)
127 put_byte(pb, val >> i*8);
130 static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
132 put_ebml_id(pb, elementid);
133 put_ebml_size(pb, 8, 0);
134 put_be64(pb, av_dbl2int(val));
137 static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
138 const uint8_t *buf, int size)
140 put_ebml_id(pb, elementid);
141 put_ebml_size(pb, size, 0);
142 put_buffer(pb, buf, size);
145 static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
147 put_ebml_binary(pb, elementid, str, strlen(str));
151 * Writes a void element of a given size. Useful for reserving space in the file to be
154 * @param size The amount of space to reserve, which must be at least 2.
156 static void put_ebml_void(ByteIOContext *pb, uint64_t size)
158 offset_t currentpos = url_ftell(pb);
163 put_ebml_id(pb, EBML_ID_VOID);
164 // we need to subtract the length needed to store the size from the size we need to reserve
165 // so 2 cases, we use 8 bytes to store the size if possible, 1 byte otherwise
167 put_ebml_size(pb, size-1, 0);
169 put_ebml_size(pb, size-9, 8);
170 url_fseek(pb, currentpos + size, SEEK_SET);
173 static offset_t start_ebml_master(ByteIOContext *pb, unsigned int elementid)
175 put_ebml_id(pb, elementid);
176 // XXX: this always reserves the maximum needed space to store any size value
177 // we should be smarter (additional parameter for expected size?)
178 put_ebml_size_unknown(pb, 8);
179 return url_ftell(pb);
182 static void end_ebml_master(ByteIOContext *pb, offset_t start)
184 offset_t pos = url_ftell(pb);
186 url_fseek(pb, start - 8, SEEK_SET);
187 put_ebml_size(pb, pos - start, 8);
188 url_fseek(pb, pos, SEEK_SET);
191 static void put_xiph_size(ByteIOContext *pb, int size)
194 for (i = 0; i < size / 255; i++)
196 put_byte(pb, size % 255);
200 * Initialize a mkv_seekhead element to be ready to index level 1 Matroska elements.
201 * If a maximum number of elements is specified, enough space will be reserved at
202 * the current file location to write a seek head of that size.
204 * @param segment_offset the absolute offset into the file that the segment begins
205 * @param numelements the maximum number of elements that will be indexed by this
206 * seek head, 0 if unlimited.
208 static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, offset_t segment_offset, int numelements)
210 mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
211 if (new_seekhead == NULL)
214 new_seekhead->segment_offset = segment_offset;
216 if (numelements > 0) {
217 new_seekhead->filepos = url_ftell(pb);
218 // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID and size,
219 // and 3 bytes to guarantee that an EBML void element will fit afterwards
220 // XXX: 28 bytes right now because begin_ebml_master() reserves more than necessary
221 new_seekhead->reserved_size = numelements * 28 + 13;
222 new_seekhead->max_entries = numelements;
223 put_ebml_void(pb, new_seekhead->reserved_size);
228 static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
230 mkv_seekhead_entry *entries = seekhead->entries;
231 int new_entry = seekhead->num_entries;
233 // don't store more elements than we reserved space for
234 if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
237 entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
241 entries[new_entry].elementid = elementid;
242 entries[new_entry].segmentpos = filepos - seekhead->segment_offset;
244 seekhead->entries = entries;
245 seekhead->num_entries++;
251 * Write the seek head to the file and free it. If a maximum number of elements was
252 * specified to mkv_start_seekhead(), the seek head will be written at the location
253 * reserved for it. Otherwise, it is written at the current location in the file.
255 * @return the file offset where the seekhead was written
257 static offset_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
259 offset_t metaseek, seekentry, currentpos;
262 currentpos = url_ftell(pb);
264 if (seekhead->reserved_size > 0)
265 url_fseek(pb, seekhead->filepos, SEEK_SET);
267 metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD);
268 for (i = 0; i < seekhead->num_entries; i++) {
269 mkv_seekhead_entry *entry = &seekhead->entries[i];
271 seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY);
273 put_ebml_id(pb, MATROSKA_ID_SEEKID);
274 put_ebml_size(pb, ebml_id_size(entry->elementid), 0);
275 put_ebml_id(pb, entry->elementid);
277 put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
278 end_ebml_master(pb, seekentry);
280 end_ebml_master(pb, metaseek);
282 if (seekhead->reserved_size > 0) {
283 uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
284 put_ebml_void(pb, remaining);
285 url_fseek(pb, currentpos, SEEK_SET);
287 currentpos = seekhead->filepos;
289 av_free(seekhead->entries);
295 static mkv_cues * mkv_start_cues(offset_t segment_offset)
297 mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
301 cues->segment_offset = segment_offset;
305 static int mkv_add_cuepoint(mkv_cues *cues, AVPacket *pkt, offset_t cluster_pos)
307 mkv_cuepoint *entries = cues->entries;
308 int new_entry = cues->num_entries;
310 entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
314 entries[new_entry].pts = pkt->pts;
315 entries[new_entry].tracknum = pkt->stream_index + 1;
316 entries[new_entry].cluster_pos = cluster_pos - cues->segment_offset;
318 cues->entries = entries;
323 static offset_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues)
325 offset_t currentpos, cues_element;
328 currentpos = url_ftell(pb);
329 cues_element = start_ebml_master(pb, MATROSKA_ID_CUES);
331 for (i = 0; i < cues->num_entries; i++) {
332 offset_t cuepoint, track_positions;
333 mkv_cuepoint *entry = &cues->entries[i];
334 uint64_t pts = entry->pts;
336 cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY);
337 put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
339 // put all the entries from different tracks that have the exact same
340 // timestamp into the same CuePoint
341 for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
342 track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION);
343 put_ebml_uint(pb, MATROSKA_ID_CUETRACK , entry[j].tracknum );
344 put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
345 end_ebml_master(pb, track_positions);
348 end_ebml_master(pb, cuepoint);
350 end_ebml_master(pb, cues_element);
352 av_free(cues->entries);
357 static int put_xiph_codecpriv(ByteIOContext *pb, AVCodecContext *codec)
359 offset_t codecprivate;
360 uint8_t *header_start[3];
362 int first_header_size;
365 if (codec->codec_id == CODEC_ID_VORBIS)
366 first_header_size = 30;
368 first_header_size = 42;
370 if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
371 first_header_size, header_start, header_len) < 0) {
372 av_log(codec, AV_LOG_ERROR, "Extradata corrupt.\n");
376 codecprivate = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
377 put_byte(pb, 2); // number packets - 1
378 for (j = 0; j < 2; j++) {
379 put_xiph_size(pb, header_len[j]);
381 for (j = 0; j < 3; j++)
382 put_buffer(pb, header_start[j], header_len[j]);
383 end_ebml_master(pb, codecprivate);
388 #define FLAC_STREAMINFO_SIZE 34
390 static int put_flac_codecpriv(ByteIOContext *pb, AVCodecContext *codec)
392 offset_t codecpriv = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
394 // if the extradata_size is greater than FLAC_STREAMINFO_SIZE,
395 // assume that it's in Matroska's format already
396 if (codec->extradata_size < FLAC_STREAMINFO_SIZE) {
397 av_log(codec, AV_LOG_ERROR, "Invalid FLAC extradata\n");
399 } else if (codec->extradata_size == FLAC_STREAMINFO_SIZE) {
400 // only the streaminfo packet
402 put_xiph_size(pb, codec->extradata_size);
403 av_log(codec, AV_LOG_ERROR, "Only one packet\n");
405 put_buffer(pb, codec->extradata, codec->extradata_size);
406 end_ebml_master(pb, codecpriv);
410 static void get_aac_sample_rates(AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
412 static const int aac_sample_rates[] = {
413 96000, 88200, 64000, 48000, 44100, 32000,
414 24000, 22050, 16000, 12000, 11025, 8000,
418 if (codec->extradata_size < 2) {
419 av_log(codec, AV_LOG_WARNING, "no aac extradata, unable to determine sample rate\n");
423 sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
425 av_log(codec, AV_LOG_WARNING, "aac samplerate index out of bounds\n");
428 *sample_rate = aac_sample_rates[sri];
430 // if sbr, get output sample rate as well
431 if (codec->extradata_size == 5) {
432 sri = (codec->extradata[4] >> 3) & 0xF;
434 av_log(codec, AV_LOG_WARNING, "aac output samplerate index out of bounds\n");
437 *output_sample_rate = aac_sample_rates[sri];
441 static int mkv_write_tracks(AVFormatContext *s)
443 MatroskaMuxContext *mkv = s->priv_data;
444 ByteIOContext *pb = &s->pb;
448 if (mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb)) < 0)
451 tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS);
452 for (i = 0; i < s->nb_streams; i++) {
453 AVStream *st = s->streams[i];
454 AVCodecContext *codec = st->codec;
455 offset_t subinfo, track;
457 int bit_depth = av_get_bits_per_sample(codec->codec_id);
458 int sample_rate = codec->sample_rate;
459 int output_sample_rate = 0;
461 if (codec->codec_id == CODEC_ID_AAC)
462 get_aac_sample_rates(codec, &sample_rate, &output_sample_rate);
464 track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY);
465 put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
466 put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
467 put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
470 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, st->language);
472 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, "und");
474 // look for a codec id string specific to mkv to use, if none are found, use AVI codes
475 for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
476 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
477 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
484 if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA) {
485 if (put_xiph_codecpriv(pb, codec) < 0)
487 } else if (codec->codec_id == CODEC_ID_FLAC) {
488 if (put_flac_codecpriv(pb, codec) < 0)
490 } else if (codec->extradata_size) {
491 put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codec->extradata, codec->extradata_size);
495 switch (codec->codec_type) {
496 case CODEC_TYPE_VIDEO:
497 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
501 // if there is no mkv-specific codec id, use VFW mode
502 if (!codec->codec_tag)
503 codec->codec_tag = codec_get_tag(codec_bmp_tags, codec->codec_id);
505 put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_VIDEO_VFW_FOURCC);
506 bmp_header = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
507 put_bmp_header(pb, codec, codec_bmp_tags, 0);
508 end_ebml_master(pb, bmp_header);
510 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO);
511 // XXX: interlace flag?
512 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
513 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
514 if (codec->sample_aspect_ratio.num) {
515 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , codec->sample_aspect_ratio.num);
516 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->sample_aspect_ratio.den);
518 end_ebml_master(pb, subinfo);
521 case CODEC_TYPE_AUDIO:
522 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
526 // no mkv-specific ID, use ACM mode
527 codec->codec_tag = codec_get_tag(codec_wav_tags, codec->codec_id);
528 if (!codec->codec_tag) {
529 av_log(s, AV_LOG_ERROR, "no codec id found for stream %d", i);
533 put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_AUDIO_ACM);
534 wav_header = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
535 put_wav_header(pb, codec);
536 end_ebml_master(pb, wav_header);
538 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO);
539 put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
540 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
541 if (output_sample_rate)
542 put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
544 put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
545 end_ebml_master(pb, subinfo);
548 case CODEC_TYPE_SUBTITLE:
549 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
552 av_log(s, AV_LOG_ERROR, "Only audio and video are supported for Matroska.");
555 end_ebml_master(pb, track);
557 // ms precision is the de-facto standard timescale for mkv files
558 av_set_pts_info(st, 64, 1, 1000);
560 end_ebml_master(pb, tracks);
564 static int mkv_write_header(AVFormatContext *s)
566 MatroskaMuxContext *mkv = s->priv_data;
567 ByteIOContext *pb = &s->pb;
568 offset_t ebml_header, segment_info;
570 mkv->md5_ctx = av_mallocz(av_md5_size);
571 av_md5_init(mkv->md5_ctx);
573 ebml_header = start_ebml_master(pb, EBML_ID_HEADER);
574 put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
575 put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
576 put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
577 put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
578 put_ebml_string (pb, EBML_ID_DOCTYPE , "matroska");
579 put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2);
580 put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2);
581 end_ebml_master(pb, ebml_header);
583 mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT);
584 mkv->segment_offset = url_ftell(pb);
586 // we write 2 seek heads - one at the end of the file to point to each cluster, and
587 // one at the beginning to point to all other level one elements (including the seek
588 // head at the end of the file), which isn't more than 10 elements if we only write one
589 // of each other currently defined level 1 element
590 mkv->main_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 10);
591 mkv->cluster_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 0);
593 if (mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb)) < 0)
596 segment_info = start_ebml_master(pb, MATROSKA_ID_INFO);
597 put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
598 if (strlen(s->title))
599 put_ebml_string(pb, MATROSKA_ID_TITLE, s->title);
600 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
601 put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
602 put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
604 // reserve space to write the segment UID later
605 mkv->segment_uid = url_ftell(pb);
606 put_ebml_void(pb, 19);
609 // reserve space for the duration
611 mkv->duration_offset = url_ftell(pb);
612 put_ebml_void(pb, 11); // assumes double-precision float to be written
613 end_ebml_master(pb, segment_info);
615 if (mkv_write_tracks(s) < 0)
618 if (mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb)) < 0)
621 mkv->cluster_pos = url_ftell(pb);
622 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER);
623 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0);
624 mkv->cluster_pts = 0;
626 mkv->cues = mkv_start_cues(mkv->segment_offset);
627 if (mkv->cues == NULL)
633 static void mkv_write_block(AVFormatContext *s, unsigned int blockid, AVPacket *pkt, int flags)
635 MatroskaMuxContext *mkv = s->priv_data;
636 ByteIOContext *pb = &s->pb;
638 av_log(s, AV_LOG_DEBUG, "Writing block at offset %llu, size %d, pts %lld, dts %lld, duration %d, flags %d\n",
639 url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
640 put_ebml_id(pb, blockid);
641 put_ebml_size(pb, pkt->size + 4, 0);
642 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
643 put_be16(pb, pkt->pts - mkv->cluster_pts);
645 put_buffer(pb, pkt->data, pkt->size);
648 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
650 MatroskaMuxContext *mkv = s->priv_data;
651 ByteIOContext *pb = &s->pb;
652 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
653 int keyframe = !!(pkt->flags & PKT_FLAG_KEY);
655 // start a new cluster every 5 MB or 5 sec
656 if (url_ftell(pb) > mkv->cluster + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) {
657 av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %llu bytes, pts %llu\n", url_ftell(pb), pkt->pts);
658 end_ebml_master(pb, mkv->cluster);
660 if (mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb)) < 0)
663 mkv->cluster_pos = url_ftell(pb);
664 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER);
665 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts);
666 mkv->cluster_pts = pkt->pts;
667 av_md5_update(mkv->md5_ctx, pkt->data, FFMIN(200, pkt->size));
670 if (codec->codec_type != CODEC_TYPE_SUBTITLE) {
671 mkv_write_block(s, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
673 offset_t blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP);
674 mkv_write_block(s, MATROSKA_ID_BLOCK, pkt, 0);
675 put_ebml_uint(pb, MATROSKA_ID_DURATION, pkt->duration);
676 end_ebml_master(pb, blockgroup);
679 if (codec->codec_type == CODEC_TYPE_VIDEO && keyframe) {
680 if (mkv_add_cuepoint(mkv->cues, pkt, mkv->cluster_pos) < 0)
684 mkv->duration = pkt->pts + pkt->duration;
688 static int mkv_write_trailer(AVFormatContext *s)
690 MatroskaMuxContext *mkv = s->priv_data;
691 ByteIOContext *pb = &s->pb;
692 offset_t currentpos, second_seekhead, cuespos;
694 end_ebml_master(pb, mkv->cluster);
696 cuespos = mkv_write_cues(pb, mkv->cues);
697 second_seekhead = mkv_write_seekhead(pb, mkv->cluster_seekhead);
699 mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES , cuespos);
700 mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_SEEKHEAD, second_seekhead);
701 mkv_write_seekhead(pb, mkv->main_seekhead);
703 // update the duration
704 av_log(s, AV_LOG_DEBUG, "end duration = %llu\n", mkv->duration);
705 currentpos = url_ftell(pb);
706 url_fseek(pb, mkv->duration_offset, SEEK_SET);
707 put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
709 // write the md5sum of some frames as the segment UID
710 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
711 uint8_t segment_uid[16];
712 av_md5_final(mkv->md5_ctx, segment_uid);
713 url_fseek(pb, mkv->segment_uid, SEEK_SET);
714 put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
716 url_fseek(pb, currentpos, SEEK_SET);
718 end_ebml_master(pb, mkv->segment);
719 av_free(mkv->md5_ctx);
723 AVOutputFormat matroska_muxer = {
725 "Matroska File Format",
728 sizeof(MatroskaMuxContext),
734 .codec_tag = (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},
737 AVOutputFormat matroska_audio_muxer = {
739 "Matroska File Format",
742 sizeof(MatroskaMuxContext),
748 .codec_tag = (const AVCodecTag*[]){codec_wav_tags, 0},