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 #include "libavutil/intreadwrite.h"
29 #include "libavutil/md5.h"
30 #include "libavcodec/xiph.h"
31 #include "libavcodec/mpeg4audio.h"
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
38 typedef struct mkv_seekhead_entry {
39 unsigned int elementid;
43 typedef struct mkv_seekhead {
45 int64_t segment_offset; ///< the file offset to the beginning of the segment
46 int reserved_size; ///< -1 if appending to file
48 mkv_seekhead_entry *entries;
55 int64_t cluster_pos; ///< file offset of the cluster containing the block
59 int64_t segment_offset;
60 mkv_cuepoint *entries;
68 typedef struct MatroskaMuxContext {
69 ByteIOContext *dyn_bc;
71 int64_t segment_offset;
74 int64_t cluster_pos; ///< file offset of the current cluster
76 int64_t duration_offset;
78 mkv_seekhead *main_seekhead;
79 mkv_seekhead *cluster_seekhead;
83 struct AVMD5 *md5_ctx;
87 /** 2 bytes * 3 for EBML IDs, 3 1-byte EBML lengths, 8 bytes for 64 bit
88 * offset, 4 bytes for target EBML ID */
89 #define MAX_SEEKENTRY_SIZE 21
91 /** per-cuepoint-track - 3 1-byte EBML IDs, 3 1-byte EBML sizes, 2
93 #define MAX_CUETRACKPOS_SIZE 22
95 /** per-cuepoint - 2 1-byte EBML IDs, 2 1-byte EBML sizes, 8-byte uint max */
96 #define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
99 static int ebml_id_size(unsigned int id)
101 return (av_log2(id+1)-1)/7+1;
104 static void put_ebml_id(ByteIOContext *pb, unsigned int id)
106 int i = ebml_id_size(id);
108 put_byte(pb, id >> (i*8));
112 * Write an EBML size meaning "unknown size".
114 * @param bytes The number of bytes the size should occupy (maximum: 8).
116 static void put_ebml_size_unknown(ByteIOContext *pb, int bytes)
119 put_byte(pb, 0x1ff >> bytes);
125 * Calculate how many bytes are needed to represent a given number in EBML.
127 static int ebml_num_size(uint64_t num)
130 while ((num+1) >> bytes*7) bytes++;
135 * Write a number in EBML variable length format.
137 * @param bytes The number of bytes that need to be used to write the number.
138 * If zero, any number of bytes can be used.
140 static void put_ebml_num(ByteIOContext *pb, uint64_t num, int bytes)
142 int i, needed_bytes = ebml_num_size(num);
144 // sizes larger than this are currently undefined in EBML
145 assert(num < (1ULL<<56)-1);
148 // don't care how many bytes are used, so use the min
149 bytes = needed_bytes;
150 // the bytes needed to write the given size would exceed the bytes
151 // that we need to use, so write unknown size. This shouldn't happen.
152 assert(bytes >= needed_bytes);
154 num |= 1ULL << bytes*7;
155 for (i = bytes - 1; i >= 0; i--)
156 put_byte(pb, num >> i*8);
159 static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
163 while (tmp>>=8) bytes++;
165 put_ebml_id(pb, elementid);
166 put_ebml_num(pb, bytes, 0);
167 for (i = bytes - 1; i >= 0; i--)
168 put_byte(pb, val >> i*8);
171 static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
173 put_ebml_id(pb, elementid);
174 put_ebml_num(pb, 8, 0);
175 put_be64(pb, av_dbl2int(val));
178 static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
179 const uint8_t *buf, int size)
181 put_ebml_id(pb, elementid);
182 put_ebml_num(pb, size, 0);
183 put_buffer(pb, buf, size);
186 static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
188 put_ebml_binary(pb, elementid, str, strlen(str));
192 * Writes a void element of a given size. Useful for reserving space in
193 * the file to be written to later.
195 * @param size The number of bytes to reserve, which must be at least 2.
197 static void put_ebml_void(ByteIOContext *pb, uint64_t size)
199 int64_t currentpos = url_ftell(pb);
203 put_ebml_id(pb, EBML_ID_VOID);
204 // we need to subtract the length needed to store the size from the
205 // size we need to reserve so 2 cases, we use 8 bytes to store the
206 // size if possible, 1 byte otherwise
208 put_ebml_num(pb, size-1, 0);
210 put_ebml_num(pb, size-9, 8);
211 while(url_ftell(pb) < currentpos + size)
215 static ebml_master start_ebml_master(ByteIOContext *pb, unsigned int elementid, uint64_t expectedsize)
217 int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
218 put_ebml_id(pb, elementid);
219 put_ebml_size_unknown(pb, bytes);
220 return (ebml_master){ url_ftell(pb), bytes };
223 static void end_ebml_master(ByteIOContext *pb, ebml_master master)
225 int64_t pos = url_ftell(pb);
227 if (url_fseek(pb, master.pos - master.sizebytes, SEEK_SET) < 0)
229 put_ebml_num(pb, pos - master.pos, master.sizebytes);
230 url_fseek(pb, pos, SEEK_SET);
233 static void put_xiph_size(ByteIOContext *pb, int size)
236 for (i = 0; i < size / 255; i++)
238 put_byte(pb, size % 255);
242 * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
243 * elements. If a maximum number of elements is specified, enough space
244 * will be reserved at the current file location to write a seek head of
247 * @param segment_offset The absolute offset to the position in the file
248 * where the segment begins.
249 * @param numelements The maximum number of elements that will be indexed
250 * by this seek head, 0 if unlimited.
252 static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, int64_t segment_offset, int numelements)
254 mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
255 if (new_seekhead == NULL)
258 new_seekhead->segment_offset = segment_offset;
260 if (numelements > 0) {
261 new_seekhead->filepos = url_ftell(pb);
262 // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
263 // and size, and 3 bytes to guarantee that an EBML void element
264 // will fit afterwards
265 new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
266 new_seekhead->max_entries = numelements;
267 put_ebml_void(pb, new_seekhead->reserved_size);
272 static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
274 mkv_seekhead_entry *entries = seekhead->entries;
276 // don't store more elements than we reserved space for
277 if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
280 entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
282 return AVERROR(ENOMEM);
284 entries[seekhead->num_entries ].elementid = elementid;
285 entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
287 seekhead->entries = entries;
292 * Write the seek head to the file and free it. If a maximum number of
293 * elements was specified to mkv_start_seekhead(), the seek head will
294 * be written at the location reserved for it. Otherwise, it is written
295 * at the current location in the file.
297 * @return The file offset where the seekhead was written,
298 * -1 if an error occurred.
300 static int64_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
302 ebml_master metaseek, seekentry;
306 currentpos = url_ftell(pb);
308 if (seekhead->reserved_size > 0)
309 if (url_fseek(pb, seekhead->filepos, SEEK_SET) < 0)
312 metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
313 for (i = 0; i < seekhead->num_entries; i++) {
314 mkv_seekhead_entry *entry = &seekhead->entries[i];
316 seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
318 put_ebml_id(pb, MATROSKA_ID_SEEKID);
319 put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
320 put_ebml_id(pb, entry->elementid);
322 put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
323 end_ebml_master(pb, seekentry);
325 end_ebml_master(pb, metaseek);
327 if (seekhead->reserved_size > 0) {
328 uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
329 put_ebml_void(pb, remaining);
330 url_fseek(pb, currentpos, SEEK_SET);
332 currentpos = seekhead->filepos;
334 av_free(seekhead->entries);
340 static mkv_cues * mkv_start_cues(int64_t segment_offset)
342 mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
346 cues->segment_offset = segment_offset;
350 static int mkv_add_cuepoint(mkv_cues *cues, int stream, int64_t ts, int64_t cluster_pos)
352 mkv_cuepoint *entries = cues->entries;
354 entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
356 return AVERROR(ENOMEM);
361 entries[cues->num_entries ].pts = ts;
362 entries[cues->num_entries ].tracknum = stream + 1;
363 entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
365 cues->entries = entries;
369 static int64_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues, int num_tracks)
371 ebml_master cues_element;
375 currentpos = url_ftell(pb);
376 cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
378 for (i = 0; i < cues->num_entries; i++) {
379 ebml_master cuepoint, track_positions;
380 mkv_cuepoint *entry = &cues->entries[i];
381 uint64_t pts = entry->pts;
383 cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
384 put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
386 // put all the entries from different tracks that have the exact same
387 // timestamp into the same CuePoint
388 for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
389 track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
390 put_ebml_uint(pb, MATROSKA_ID_CUETRACK , entry[j].tracknum );
391 put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
392 end_ebml_master(pb, track_positions);
395 end_ebml_master(pb, cuepoint);
397 end_ebml_master(pb, cues_element);
399 av_free(cues->entries);
404 static int put_xiph_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
406 uint8_t *header_start[3];
408 int first_header_size;
411 if (codec->codec_id == CODEC_ID_VORBIS)
412 first_header_size = 30;
414 first_header_size = 42;
416 if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
417 first_header_size, header_start, header_len) < 0) {
418 av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
422 put_byte(pb, 2); // number packets - 1
423 for (j = 0; j < 2; j++) {
424 put_xiph_size(pb, header_len[j]);
426 for (j = 0; j < 3; j++)
427 put_buffer(pb, header_start[j], header_len[j]);
432 static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
436 if (codec->extradata_size < 2) {
437 av_log(s, AV_LOG_WARNING, "No AAC extradata, unable to determine samplerate.\n");
441 sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
443 av_log(s, AV_LOG_WARNING, "AAC samplerate index out of bounds\n");
446 *sample_rate = ff_mpeg4audio_sample_rates[sri];
448 // if sbr, get output sample rate as well
449 if (codec->extradata_size == 5) {
450 sri = (codec->extradata[4] >> 3) & 0xF;
452 av_log(s, AV_LOG_WARNING, "AAC output samplerate index out of bounds\n");
455 *output_sample_rate = ff_mpeg4audio_sample_rates[sri];
459 static int mkv_write_codecprivate(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec, int native_id, int qt_id)
461 ByteIOContext *dyn_cp;
463 int ret, codecpriv_size;
465 ret = url_open_dyn_buf(&dyn_cp);
470 if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA)
471 ret = put_xiph_codecpriv(s, dyn_cp, codec);
472 else if (codec->codec_id == CODEC_ID_FLAC)
473 ret = ff_flac_write_header(dyn_cp, codec, 1);
474 else if (codec->codec_id == CODEC_ID_H264)
475 ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
476 else if (codec->extradata_size)
477 put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
478 } else if (codec->codec_type == CODEC_TYPE_VIDEO) {
480 if (!codec->codec_tag)
481 codec->codec_tag = ff_codec_get_tag(codec_movvideo_tags, codec->codec_id);
482 if (codec->extradata_size)
483 put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
485 if (!codec->codec_tag)
486 codec->codec_tag = ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id);
487 if (!codec->codec_tag) {
488 av_log(s, AV_LOG_ERROR, "No bmp codec ID found.\n");
492 ff_put_bmp_header(dyn_cp, codec, ff_codec_bmp_tags, 0);
495 } else if (codec->codec_type == CODEC_TYPE_AUDIO) {
496 if (!codec->codec_tag)
497 codec->codec_tag = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);
498 if (!codec->codec_tag) {
499 av_log(s, AV_LOG_ERROR, "No wav codec ID found.\n");
503 ff_put_wav_header(dyn_cp, codec);
506 codecpriv_size = url_close_dyn_buf(dyn_cp, &codecpriv);
508 put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
513 static int mkv_write_tracks(AVFormatContext *s)
515 MatroskaMuxContext *mkv = s->priv_data;
516 ByteIOContext *pb = s->pb;
520 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb));
521 if (ret < 0) return ret;
523 tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
524 for (i = 0; i < s->nb_streams; i++) {
525 AVStream *st = s->streams[i];
526 AVCodecContext *codec = st->codec;
527 ebml_master subinfo, track;
530 int bit_depth = av_get_bits_per_sample(codec->codec_id);
531 int sample_rate = codec->sample_rate;
532 int output_sample_rate = 0;
536 bit_depth = av_get_bits_per_sample_format(codec->sample_fmt);
538 if (codec->codec_id == CODEC_ID_AAC)
539 get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
541 track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
542 put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
543 put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
544 put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
545 put_ebml_float(pb, MATROSKA_ID_TRACKTIMECODESCALE, 1.0);
547 if ((tag = av_metadata_get(st->metadata, "title", NULL, 0)))
548 put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
549 tag = av_metadata_get(st->metadata, "language", NULL, 0);
550 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
553 put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
555 // look for a codec ID string specific to mkv to use,
556 // if none are found, use AVI codes
557 for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
558 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
559 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
565 switch (codec->codec_type) {
566 case CODEC_TYPE_VIDEO:
567 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
570 ff_codec_get_tag(codec_movvideo_tags, codec->codec_id) &&
571 (!ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id)
572 || codec->codec_id == CODEC_ID_SVQ1
573 || codec->codec_id == CODEC_ID_SVQ3
574 || codec->codec_id == CODEC_ID_CINEPAK))
578 put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
579 else if (!native_id) {
580 // if there is no mkv-specific codec ID, use VFW mode
581 put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
582 mkv->tracks[i].write_dts = 1;
585 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
586 // XXX: interlace flag?
587 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
588 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
589 if (st->sample_aspect_ratio.num) {
590 int d_width = codec->width*av_q2d(st->sample_aspect_ratio);
591 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width);
592 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height);
594 end_ebml_master(pb, subinfo);
597 case CODEC_TYPE_AUDIO:
598 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
601 // no mkv-specific ID, use ACM mode
602 put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
604 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
605 put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
606 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
607 if (output_sample_rate)
608 put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
610 put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
611 end_ebml_master(pb, subinfo);
614 case CODEC_TYPE_SUBTITLE:
615 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
618 av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.");
621 ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
622 if (ret < 0) return ret;
624 end_ebml_master(pb, track);
626 // ms precision is the de-facto standard timescale for mkv files
627 av_set_pts_info(st, 64, 1, 1000);
629 end_ebml_master(pb, tracks);
633 static int mkv_write_chapters(AVFormatContext *s)
635 MatroskaMuxContext *mkv = s->priv_data;
636 ByteIOContext *pb = s->pb;
637 ebml_master chapters, editionentry;
638 AVRational scale = {1, 1E9};
644 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CHAPTERS, url_ftell(pb));
645 if (ret < 0) return ret;
647 chapters = start_ebml_master(pb, MATROSKA_ID_CHAPTERS , 0);
648 editionentry = start_ebml_master(pb, MATROSKA_ID_EDITIONENTRY, 0);
649 put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGDEFAULT, 1);
650 put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGHIDDEN , 0);
651 for (i = 0; i < s->nb_chapters; i++) {
652 ebml_master chapteratom, chapterdisplay;
653 AVChapter *c = s->chapters[i];
654 AVMetadataTag *t = NULL;
656 chapteratom = start_ebml_master(pb, MATROSKA_ID_CHAPTERATOM, 0);
657 put_ebml_uint(pb, MATROSKA_ID_CHAPTERUID, c->id);
658 put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMESTART,
659 av_rescale_q(c->start, c->time_base, scale));
660 put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMEEND,
661 av_rescale_q(c->end, c->time_base, scale));
662 put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGHIDDEN , 0);
663 put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGENABLED, 1);
664 if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {
665 chapterdisplay = start_ebml_master(pb, MATROSKA_ID_CHAPTERDISPLAY, 0);
666 put_ebml_string(pb, MATROSKA_ID_CHAPSTRING, t->value);
667 put_ebml_string(pb, MATROSKA_ID_CHAPLANG , "und");
668 end_ebml_master(pb, chapterdisplay);
670 end_ebml_master(pb, chapteratom);
672 end_ebml_master(pb, editionentry);
673 end_ebml_master(pb, chapters);
677 static int mkv_write_header(AVFormatContext *s)
679 MatroskaMuxContext *mkv = s->priv_data;
680 ByteIOContext *pb = s->pb;
681 ebml_master ebml_header, segment_info;
685 mkv->md5_ctx = av_mallocz(av_md5_size);
686 av_md5_init(mkv->md5_ctx);
687 mkv->tracks = av_mallocz(s->nb_streams * sizeof(*mkv->tracks));
689 ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
690 put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
691 put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
692 put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
693 put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
694 put_ebml_string (pb, EBML_ID_DOCTYPE , "matroska");
695 put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2);
696 put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2);
697 end_ebml_master(pb, ebml_header);
699 mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
700 mkv->segment_offset = url_ftell(pb);
702 // we write 2 seek heads - one at the end of the file to point to each
703 // cluster, and one at the beginning to point to all other level one
704 // elements (including the seek head at the end of the file), which
705 // isn't more than 10 elements if we only write one of each other
706 // currently defined level 1 element
707 mkv->main_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 10);
708 mkv->cluster_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 0);
709 if (mkv->main_seekhead == NULL || mkv->cluster_seekhead == NULL)
710 return AVERROR(ENOMEM);
712 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb));
713 if (ret < 0) return ret;
715 segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
716 put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
717 if ((tag = av_metadata_get(s->metadata, "title", NULL, 0)))
718 put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
719 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
720 put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
721 put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
723 // reserve space to write the segment UID later
724 mkv->segment_uid = url_ftell(pb);
725 put_ebml_void(pb, 19);
728 // reserve space for the duration
730 mkv->duration_offset = url_ftell(pb);
731 put_ebml_void(pb, 11); // assumes double-precision float to be written
732 end_ebml_master(pb, segment_info);
734 ret = mkv_write_tracks(s);
735 if (ret < 0) return ret;
737 ret = mkv_write_chapters(s);
738 if (ret < 0) return ret;
740 if (url_is_streamed(s->pb))
741 mkv_write_seekhead(pb, mkv->main_seekhead);
743 mkv->cues = mkv_start_cues(mkv->segment_offset);
744 if (mkv->cues == NULL)
745 return AVERROR(ENOMEM);
747 put_flush_packet(pb);
751 static int mkv_blockgroup_size(int pkt_size)
753 int size = pkt_size + 4;
754 size += ebml_num_size(size);
755 size += 2; // EBML ID for block and block duration
756 size += 8; // max size of block duration
757 size += ebml_num_size(size);
758 size += 1; // blockgroup EBML ID
762 static int ass_get_duration(const uint8_t *p)
764 int sh, sm, ss, sc, eh, em, es, ec;
767 if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
768 &sh, &sm, &ss, &sc, &eh, &em, &es, &ec) != 8)
770 start = 3600000*sh + 60000*sm + 1000*ss + 10*sc;
771 end = 3600000*eh + 60000*em + 1000*es + 10*ec;
775 static int mkv_write_ass_blocks(AVFormatContext *s, ByteIOContext *pb, AVPacket *pkt)
777 MatroskaMuxContext *mkv = s->priv_data;
778 int i, layer = 0, max_duration = 0, size, line_size, data_size = pkt->size;
779 uint8_t *start, *end, *data = pkt->data;
780 ebml_master blockgroup;
784 int duration = ass_get_duration(data);
785 max_duration = FFMAX(duration, max_duration);
786 end = memchr(data, '\n', data_size);
787 size = line_size = end ? end-data+1 : data_size;
788 size -= end ? (end[-1]=='\r')+1 : 0;
790 for (i=0; i<3; i++, start++)
791 if (!(start = memchr(start, ',', size-(start-data))))
793 size -= start - data;
794 sscanf(data, "Dialogue: %d,", &layer);
795 i = snprintf(buffer, sizeof(buffer), "%"PRId64",%d,",
796 s->streams[pkt->stream_index]->nb_frames++, layer);
797 size = FFMIN(i+size, sizeof(buffer));
798 memcpy(buffer+i, start, size-i);
800 av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
801 "pts %" PRId64 ", duration %d\n",
802 url_ftell(pb), size, pkt->pts, duration);
803 blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
804 put_ebml_id(pb, MATROSKA_ID_BLOCK);
805 put_ebml_num(pb, size+4, 0);
806 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
807 put_be16(pb, pkt->pts - mkv->cluster_pts);
809 put_buffer(pb, buffer, size);
810 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
811 end_ebml_master(pb, blockgroup);
814 data_size -= line_size;
820 static void mkv_write_block(AVFormatContext *s, ByteIOContext *pb,
821 unsigned int blockid, AVPacket *pkt, int flags)
823 MatroskaMuxContext *mkv = s->priv_data;
824 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
825 uint8_t *data = NULL;
826 int size = pkt->size;
827 int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
829 av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
830 "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
831 url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
832 if (codec->codec_id == CODEC_ID_H264 && codec->extradata_size > 0 &&
833 (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
834 ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
837 put_ebml_id(pb, blockid);
838 put_ebml_num(pb, size+4, 0);
839 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
840 put_be16(pb, ts - mkv->cluster_pts);
842 put_buffer(pb, data, size);
843 if (data != pkt->data)
847 static void mkv_flush_dynbuf(AVFormatContext *s)
849 MatroskaMuxContext *mkv = s->priv_data;
856 bufsize = url_close_dyn_buf(mkv->dyn_bc, &dyn_buf);
857 put_buffer(s->pb, dyn_buf, bufsize);
862 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
864 MatroskaMuxContext *mkv = s->priv_data;
865 ByteIOContext *pb = s->pb;
866 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
867 int keyframe = !!(pkt->flags & PKT_FLAG_KEY);
868 int duration = pkt->duration;
870 int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
872 if (ts == AV_NOPTS_VALUE) {
873 av_log(s, AV_LOG_ERROR, "Can't write packet with unknown timestamp\n");
874 return AVERROR(EINVAL);
877 if (url_is_streamed(s->pb)) {
879 url_open_dyn_buf(&mkv->dyn_bc);
883 if (!mkv->cluster_pos) {
884 ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
885 if (ret < 0) return ret;
887 mkv->cluster_pos = url_ftell(s->pb);
888 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
889 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, FFMAX(0, ts));
890 mkv->cluster_pts = FFMAX(0, ts);
891 av_md5_update(mkv->md5_ctx, pkt->data, FFMIN(200, pkt->size));
894 if (codec->codec_type != CODEC_TYPE_SUBTITLE) {
895 mkv_write_block(s, pb, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
896 } else if (codec->codec_id == CODEC_ID_SSA) {
897 duration = mkv_write_ass_blocks(s, pb, pkt);
899 ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
900 duration = pkt->convergence_duration;
901 mkv_write_block(s, pb, MATROSKA_ID_BLOCK, pkt, 0);
902 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
903 end_ebml_master(pb, blockgroup);
906 if (codec->codec_type == CODEC_TYPE_VIDEO && keyframe) {
907 ret = mkv_add_cuepoint(mkv->cues, pkt->stream_index, ts, mkv->cluster_pos);
908 if (ret < 0) return ret;
911 // start a new cluster every 5 MB or 5 sec, or 32k / 1 sec for streaming
912 if (url_is_streamed(s->pb) && (url_ftell(pb) > 32*1024 || ts > mkv->cluster_pts + 1000)
913 || url_ftell(pb) > mkv->cluster_pos + 5*1024*1024 || ts > mkv->cluster_pts + 5000) {
914 av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
915 " bytes, pts %" PRIu64 "\n", url_ftell(pb), ts);
916 end_ebml_master(pb, mkv->cluster);
917 mkv->cluster_pos = 0;
922 mkv->duration = FFMAX(mkv->duration, ts + duration);
926 static int mkv_write_trailer(AVFormatContext *s)
928 MatroskaMuxContext *mkv = s->priv_data;
929 ByteIOContext *pb = s->pb;
930 int64_t currentpos, second_seekhead, cuespos;
934 end_ebml_master(mkv->dyn_bc, mkv->cluster);
936 } else if (mkv->cluster_pos) {
937 end_ebml_master(pb, mkv->cluster);
940 if (!url_is_streamed(pb)) {
941 cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
942 second_seekhead = mkv_write_seekhead(pb, mkv->cluster_seekhead);
944 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES , cuespos);
945 if (ret < 0) return ret;
946 if (second_seekhead >= 0) {
947 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_SEEKHEAD, second_seekhead);
948 if (ret < 0) return ret;
950 mkv_write_seekhead(pb, mkv->main_seekhead);
952 // update the duration
953 av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
954 currentpos = url_ftell(pb);
955 url_fseek(pb, mkv->duration_offset, SEEK_SET);
956 put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
958 // write the md5sum of some frames as the segment UID
959 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
960 uint8_t segment_uid[16];
961 av_md5_final(mkv->md5_ctx, segment_uid);
962 url_fseek(pb, mkv->segment_uid, SEEK_SET);
963 put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
965 url_fseek(pb, currentpos, SEEK_SET);
968 end_ebml_master(pb, mkv->segment);
969 av_free(mkv->md5_ctx);
970 av_free(mkv->tracks);
971 put_flush_packet(pb);
975 AVOutputFormat matroska_muxer = {
977 NULL_IF_CONFIG_SMALL("Matroska file format"),
980 sizeof(MatroskaMuxContext),
986 .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
987 .codec_tag = (const AVCodecTag* const []){ff_codec_bmp_tags, ff_codec_wav_tags, 0},
988 .subtitle_codec = CODEC_ID_TEXT,
991 AVOutputFormat matroska_audio_muxer = {
993 NULL_IF_CONFIG_SMALL("Matroska file format"),
996 sizeof(MatroskaMuxContext),
1002 .flags = AVFMT_GLOBALHEADER,
1003 .codec_tag = (const AVCodecTag* const []){ff_codec_wav_tags, 0},