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);
100 * Calculate how many bytes are needed to represent a given size in EBML
102 static int ebml_size_bytes(uint64_t size)
105 while ((size+1) >> bytes*7) bytes++;
110 * Write a size in EBML variable length format.
112 * @param bytes The number of bytes that need to be used to write the size.
113 * If zero, any number of bytes can be used.
115 static void put_ebml_size(ByteIOContext *pb, uint64_t size, int bytes)
117 int i, needed_bytes = ebml_size_bytes(size);
119 // sizes larger than this are currently undefined in EBML
120 // so write "unknown" size
121 if (size >= (1ULL<<56)-1) {
122 put_ebml_size_unknown(pb, 1);
127 // don't care how many bytes are used, so use the min
128 bytes = needed_bytes;
129 else if (needed_bytes > bytes) {
130 // the bytes needed to write the given size would exceed the bytes
131 // that we need to use, so write unknown size. This shouldn't happen.
132 av_log(NULL, AV_LOG_WARNING, "Size of %llu needs %d bytes but only %d bytes reserved\n",
133 size, needed_bytes, bytes);
134 put_ebml_size_unknown(pb, bytes);
138 size |= 1ULL << bytes*7;
139 for (i = bytes - 1; i >= 0; i--)
140 put_byte(pb, size >> i*8);
143 static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
146 while (val >> bytes*8) bytes++;
148 put_ebml_id(pb, elementid);
149 put_ebml_size(pb, bytes, 0);
150 for (i = bytes - 1; i >= 0; i--)
151 put_byte(pb, val >> i*8);
154 static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
156 put_ebml_id(pb, elementid);
157 put_ebml_size(pb, 8, 0);
158 put_be64(pb, av_dbl2int(val));
161 static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
162 const uint8_t *buf, int size)
164 put_ebml_id(pb, elementid);
165 put_ebml_size(pb, size, 0);
166 put_buffer(pb, buf, size);
169 static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
171 put_ebml_binary(pb, elementid, str, strlen(str));
175 * Writes a void element of a given size. Useful for reserving space in the file to be
178 * @param size The amount of space to reserve, which must be at least 2.
180 static void put_ebml_void(ByteIOContext *pb, uint64_t size)
182 offset_t currentpos = url_ftell(pb);
187 put_ebml_id(pb, EBML_ID_VOID);
188 // we need to subtract the length needed to store the size from the size we need to reserve
189 // so 2 cases, we use 8 bytes to store the size if possible, 1 byte otherwise
191 put_ebml_size(pb, size-1, 0);
193 put_ebml_size(pb, size-9, 8);
194 url_fseek(pb, currentpos + size, SEEK_SET);
197 static offset_t start_ebml_master(ByteIOContext *pb, unsigned int elementid)
199 put_ebml_id(pb, elementid);
200 // XXX: this always reserves the maximum needed space to store any size value
201 // we should be smarter (additional parameter for expected size?)
202 put_ebml_size_unknown(pb, 8);
203 return url_ftell(pb);
206 static void end_ebml_master(ByteIOContext *pb, offset_t start)
208 offset_t pos = url_ftell(pb);
210 url_fseek(pb, start - 8, SEEK_SET);
211 put_ebml_size(pb, pos - start, 8);
212 url_fseek(pb, pos, SEEK_SET);
215 static void put_xiph_size(ByteIOContext *pb, int size)
218 for (i = 0; i < size / 255; i++)
220 put_byte(pb, size % 255);
224 * Initialize a mkv_seekhead element to be ready to index level 1 Matroska elements.
225 * If a maximum number of elements is specified, enough space will be reserved at
226 * the current file location to write a seek head of that size.
228 * @param segment_offset the absolute offset into the file that the segment begins
229 * @param numelements the maximum number of elements that will be indexed by this
230 * seek head, 0 if unlimited.
232 static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, offset_t segment_offset, int numelements)
234 mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
235 if (new_seekhead == NULL)
238 new_seekhead->segment_offset = segment_offset;
240 if (numelements > 0) {
241 new_seekhead->filepos = url_ftell(pb);
242 // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID and size,
243 // and 3 bytes to guarantee that an EBML void element will fit afterwards
244 // XXX: 28 bytes right now because begin_ebml_master() reserves more than necessary
245 new_seekhead->reserved_size = numelements * 28 + 13;
246 new_seekhead->max_entries = numelements;
247 put_ebml_void(pb, new_seekhead->reserved_size);
252 static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
254 mkv_seekhead_entry *entries = seekhead->entries;
255 int new_entry = seekhead->num_entries;
257 // don't store more elements than we reserved space for
258 if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
261 entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
265 entries[new_entry].elementid = elementid;
266 entries[new_entry].segmentpos = filepos - seekhead->segment_offset;
268 seekhead->entries = entries;
269 seekhead->num_entries++;
275 * Write the seek head to the file and free it. If a maximum number of elements was
276 * specified to mkv_start_seekhead(), the seek head will be written at the location
277 * reserved for it. Otherwise, it is written at the current location in the file.
279 * @return the file offset where the seekhead was written
281 static offset_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
283 offset_t metaseek, seekentry, currentpos;
286 currentpos = url_ftell(pb);
288 if (seekhead->reserved_size > 0)
289 url_fseek(pb, seekhead->filepos, SEEK_SET);
291 metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD);
292 for (i = 0; i < seekhead->num_entries; i++) {
293 mkv_seekhead_entry *entry = &seekhead->entries[i];
295 seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY);
297 put_ebml_id(pb, MATROSKA_ID_SEEKID);
298 put_ebml_size(pb, ebml_id_size(entry->elementid), 0);
299 put_ebml_id(pb, entry->elementid);
301 put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
302 end_ebml_master(pb, seekentry);
304 end_ebml_master(pb, metaseek);
306 if (seekhead->reserved_size > 0) {
307 uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
308 put_ebml_void(pb, remaining);
309 url_fseek(pb, currentpos, SEEK_SET);
311 currentpos = seekhead->filepos;
313 av_free(seekhead->entries);
319 static mkv_cues * mkv_start_cues(offset_t segment_offset)
321 mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
325 cues->segment_offset = segment_offset;
329 static int mkv_add_cuepoint(mkv_cues *cues, AVPacket *pkt, offset_t cluster_pos)
331 mkv_cuepoint *entries = cues->entries;
332 int new_entry = cues->num_entries;
334 entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
338 entries[new_entry].pts = pkt->pts;
339 entries[new_entry].tracknum = pkt->stream_index + 1;
340 entries[new_entry].cluster_pos = cluster_pos - cues->segment_offset;
342 cues->entries = entries;
347 static offset_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues)
349 offset_t currentpos, cues_element;
352 currentpos = url_ftell(pb);
353 cues_element = start_ebml_master(pb, MATROSKA_ID_CUES);
355 for (i = 0; i < cues->num_entries; i++) {
356 offset_t cuepoint, track_positions;
357 mkv_cuepoint *entry = &cues->entries[i];
358 uint64_t pts = entry->pts;
360 cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY);
361 put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
363 // put all the entries from different tracks that have the exact same
364 // timestamp into the same CuePoint
365 for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
366 track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION);
367 put_ebml_uint(pb, MATROSKA_ID_CUETRACK , entry[j].tracknum );
368 put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
369 end_ebml_master(pb, track_positions);
372 end_ebml_master(pb, cuepoint);
374 end_ebml_master(pb, cues_element);
376 av_free(cues->entries);
381 static int put_xiph_codecpriv(ByteIOContext *pb, AVCodecContext *codec)
383 offset_t codecprivate;
384 uint8_t *header_start[3];
386 int first_header_size;
389 if (codec->codec_id == CODEC_ID_VORBIS)
390 first_header_size = 30;
392 first_header_size = 42;
394 if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
395 first_header_size, header_start, header_len) < 0) {
396 av_log(codec, AV_LOG_ERROR, "Extradata corrupt.\n");
400 codecprivate = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
401 put_byte(pb, 2); // number packets - 1
402 for (j = 0; j < 2; j++) {
403 put_xiph_size(pb, header_len[j]);
405 for (j = 0; j < 3; j++)
406 put_buffer(pb, header_start[j], header_len[j]);
407 end_ebml_master(pb, codecprivate);
412 #define FLAC_STREAMINFO_SIZE 34
414 static int put_flac_codecpriv(ByteIOContext *pb, AVCodecContext *codec)
416 offset_t codecpriv = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
418 // if the extradata_size is greater than FLAC_STREAMINFO_SIZE,
419 // assume that it's in Matroska's format already
420 if (codec->extradata_size < FLAC_STREAMINFO_SIZE) {
421 av_log(codec, AV_LOG_ERROR, "Invalid FLAC extradata\n");
423 } else if (codec->extradata_size == FLAC_STREAMINFO_SIZE) {
424 // only the streaminfo packet
426 put_xiph_size(pb, codec->extradata_size);
427 av_log(codec, AV_LOG_ERROR, "Only one packet\n");
429 put_buffer(pb, codec->extradata, codec->extradata_size);
430 end_ebml_master(pb, codecpriv);
434 static void get_aac_sample_rates(AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
436 static const int aac_sample_rates[] = {
437 96000, 88200, 64000, 48000, 44100, 32000,
438 24000, 22050, 16000, 12000, 11025, 8000,
442 if (codec->extradata_size < 2) {
443 av_log(codec, AV_LOG_WARNING, "no aac extradata, unable to determine sample rate\n");
447 sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
449 av_log(codec, AV_LOG_WARNING, "aac samplerate index out of bounds\n");
452 *sample_rate = aac_sample_rates[sri];
454 // if sbr, get output sample rate as well
455 if (codec->extradata_size == 5) {
456 sri = (codec->extradata[4] >> 3) & 0xF;
458 av_log(codec, AV_LOG_WARNING, "aac output samplerate index out of bounds\n");
461 *output_sample_rate = aac_sample_rates[sri];
465 static int mkv_write_tracks(AVFormatContext *s)
467 MatroskaMuxContext *mkv = s->priv_data;
468 ByteIOContext *pb = &s->pb;
472 if (mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb)) < 0)
475 tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS);
476 for (i = 0; i < s->nb_streams; i++) {
477 AVStream *st = s->streams[i];
478 AVCodecContext *codec = st->codec;
479 offset_t subinfo, track;
481 int bit_depth = av_get_bits_per_sample(codec->codec_id);
482 int sample_rate = codec->sample_rate;
483 int output_sample_rate = 0;
485 if (codec->codec_id == CODEC_ID_AAC)
486 get_aac_sample_rates(codec, &sample_rate, &output_sample_rate);
488 track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY);
489 put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
490 put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
491 put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
494 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, st->language);
496 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, "und");
498 // look for a codec id string specific to mkv to use, if none are found, use AVI codes
499 for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
500 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
501 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
508 if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA) {
509 if (put_xiph_codecpriv(pb, codec) < 0)
511 } else if (codec->codec_id == CODEC_ID_FLAC) {
512 if (put_flac_codecpriv(pb, codec) < 0)
514 } else if (codec->extradata_size) {
515 put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codec->extradata, codec->extradata_size);
519 switch (codec->codec_type) {
520 case CODEC_TYPE_VIDEO:
521 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
525 // if there is no mkv-specific codec id, use VFW mode
526 if (!codec->codec_tag)
527 codec->codec_tag = codec_get_tag(codec_bmp_tags, codec->codec_id);
529 put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_VIDEO_VFW_FOURCC);
530 bmp_header = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
531 put_bmp_header(pb, codec, codec_bmp_tags, 0);
532 end_ebml_master(pb, bmp_header);
534 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO);
535 // XXX: interlace flag?
536 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
537 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
538 if (codec->sample_aspect_ratio.num) {
539 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , codec->sample_aspect_ratio.num);
540 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->sample_aspect_ratio.den);
542 end_ebml_master(pb, subinfo);
545 case CODEC_TYPE_AUDIO:
546 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
550 // no mkv-specific ID, use ACM mode
551 codec->codec_tag = codec_get_tag(codec_wav_tags, codec->codec_id);
552 if (!codec->codec_tag) {
553 av_log(s, AV_LOG_ERROR, "no codec id found for stream %d", i);
557 put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_AUDIO_ACM);
558 wav_header = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
559 put_wav_header(pb, codec);
560 end_ebml_master(pb, wav_header);
562 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO);
563 put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
564 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
565 if (output_sample_rate)
566 put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
568 put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
569 end_ebml_master(pb, subinfo);
572 case CODEC_TYPE_SUBTITLE:
573 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
576 av_log(s, AV_LOG_ERROR, "Only audio and video are supported for Matroska.");
579 end_ebml_master(pb, track);
581 // ms precision is the de-facto standard timescale for mkv files
582 av_set_pts_info(st, 64, 1, 1000);
584 end_ebml_master(pb, tracks);
588 static int mkv_write_header(AVFormatContext *s)
590 MatroskaMuxContext *mkv = s->priv_data;
591 ByteIOContext *pb = &s->pb;
592 offset_t ebml_header, segment_info;
594 mkv->md5_ctx = av_mallocz(av_md5_size);
595 av_md5_init(mkv->md5_ctx);
597 ebml_header = start_ebml_master(pb, EBML_ID_HEADER);
598 put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
599 put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
600 put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
601 put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
602 put_ebml_string (pb, EBML_ID_DOCTYPE , "matroska");
603 put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2);
604 put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2);
605 end_ebml_master(pb, ebml_header);
607 mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT);
608 mkv->segment_offset = url_ftell(pb);
610 // we write 2 seek heads - one at the end of the file to point to each cluster, and
611 // one at the beginning to point to all other level one elements (including the seek
612 // head at the end of the file), which isn't more than 10 elements if we only write one
613 // of each other currently defined level 1 element
614 mkv->main_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 10);
615 mkv->cluster_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 0);
617 if (mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb)) < 0)
620 segment_info = start_ebml_master(pb, MATROSKA_ID_INFO);
621 put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
622 if (strlen(s->title))
623 put_ebml_string(pb, MATROSKA_ID_TITLE, s->title);
624 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
625 put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
626 put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
628 // reserve space to write the segment UID later
629 mkv->segment_uid = url_ftell(pb);
630 put_ebml_void(pb, 19);
633 // reserve space for the duration
635 mkv->duration_offset = url_ftell(pb);
636 put_ebml_void(pb, 11); // assumes double-precision float to be written
637 end_ebml_master(pb, segment_info);
639 if (mkv_write_tracks(s) < 0)
642 if (mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb)) < 0)
645 mkv->cluster_pos = url_ftell(pb);
646 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER);
647 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0);
648 mkv->cluster_pts = 0;
650 mkv->cues = mkv_start_cues(mkv->segment_offset);
651 if (mkv->cues == NULL)
657 static void mkv_write_block(AVFormatContext *s, unsigned int blockid, AVPacket *pkt, int flags)
659 MatroskaMuxContext *mkv = s->priv_data;
660 ByteIOContext *pb = &s->pb;
662 av_log(s, AV_LOG_DEBUG, "Writing block at offset %llu, size %d, pts %lld, dts %lld, duration %d, flags %d\n",
663 url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
664 put_ebml_id(pb, blockid);
665 put_ebml_size(pb, pkt->size + 4, 0);
666 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
667 put_be16(pb, pkt->pts - mkv->cluster_pts);
669 put_buffer(pb, pkt->data, pkt->size);
672 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
674 MatroskaMuxContext *mkv = s->priv_data;
675 ByteIOContext *pb = &s->pb;
676 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
677 int keyframe = !!(pkt->flags & PKT_FLAG_KEY);
679 // start a new cluster every 5 MB or 5 sec
680 if (url_ftell(pb) > mkv->cluster_pos + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) {
681 av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %llu bytes, pts %llu\n", url_ftell(pb), pkt->pts);
682 end_ebml_master(pb, mkv->cluster);
684 if (mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb)) < 0)
687 mkv->cluster_pos = url_ftell(pb);
688 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER);
689 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts);
690 mkv->cluster_pts = pkt->pts;
691 av_md5_update(mkv->md5_ctx, pkt->data, FFMIN(200, pkt->size));
694 if (codec->codec_type != CODEC_TYPE_SUBTITLE) {
695 mkv_write_block(s, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
697 offset_t blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP);
698 mkv_write_block(s, MATROSKA_ID_BLOCK, pkt, 0);
699 put_ebml_uint(pb, MATROSKA_ID_DURATION, pkt->duration);
700 end_ebml_master(pb, blockgroup);
703 if (codec->codec_type == CODEC_TYPE_VIDEO && keyframe) {
704 if (mkv_add_cuepoint(mkv->cues, pkt, mkv->cluster_pos) < 0)
708 mkv->duration = pkt->pts + pkt->duration;
712 static int mkv_write_trailer(AVFormatContext *s)
714 MatroskaMuxContext *mkv = s->priv_data;
715 ByteIOContext *pb = &s->pb;
716 offset_t currentpos, second_seekhead, cuespos;
718 end_ebml_master(pb, mkv->cluster);
720 cuespos = mkv_write_cues(pb, mkv->cues);
721 second_seekhead = mkv_write_seekhead(pb, mkv->cluster_seekhead);
723 mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES , cuespos);
724 mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_SEEKHEAD, second_seekhead);
725 mkv_write_seekhead(pb, mkv->main_seekhead);
727 // update the duration
728 av_log(s, AV_LOG_DEBUG, "end duration = %llu\n", mkv->duration);
729 currentpos = url_ftell(pb);
730 url_fseek(pb, mkv->duration_offset, SEEK_SET);
731 put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
733 // write the md5sum of some frames as the segment UID
734 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
735 uint8_t segment_uid[16];
736 av_md5_final(mkv->md5_ctx, segment_uid);
737 url_fseek(pb, mkv->segment_uid, SEEK_SET);
738 put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
740 url_fseek(pb, currentpos, SEEK_SET);
742 end_ebml_master(pb, mkv->segment);
743 av_free(mkv->md5_ctx);
747 AVOutputFormat matroska_muxer = {
749 "Matroska File Format",
752 sizeof(MatroskaMuxContext),
758 .codec_tag = (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},
759 .subtitle_codec = CODEC_ID_TEXT,
762 AVOutputFormat matroska_audio_muxer = {
764 "Matroska File Format",
767 sizeof(MatroskaMuxContext),
773 .codec_tag = (const AVCodecTag*[]){codec_wav_tags, 0},