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 "avlanguage.h"
29 #include "libavutil/samplefmt.h"
30 #include "libavutil/intreadwrite.h"
31 #include "libavutil/random_seed.h"
32 #include "libavutil/lfg.h"
33 #include "libavcodec/xiph.h"
34 #include "libavcodec/mpeg4audio.h"
37 typedef struct ebml_master {
38 int64_t pos; ///< absolute offset in the file where the master's elements start
39 int sizebytes; ///< how many bytes were reserved for the size
42 typedef struct mkv_seekhead_entry {
43 unsigned int elementid;
47 typedef struct mkv_seekhead {
49 int64_t segment_offset; ///< the file offset to the beginning of the segment
50 int reserved_size; ///< -1 if appending to file
52 mkv_seekhead_entry *entries;
59 int64_t cluster_pos; ///< file offset of the cluster containing the block
63 int64_t segment_offset;
64 mkv_cuepoint *entries;
72 #define MODE_MATROSKAv2 0x01
73 #define MODE_WEBM 0x02
75 typedef struct MatroskaMuxContext {
79 int64_t segment_offset;
81 int64_t cluster_pos; ///< file offset of the current cluster
83 int64_t duration_offset;
85 mkv_seekhead *main_seekhead;
89 unsigned int audio_buffer_size;
90 AVPacket cur_audio_pkt;
94 /** 2 bytes * 3 for EBML IDs, 3 1-byte EBML lengths, 8 bytes for 64 bit
95 * offset, 4 bytes for target EBML ID */
96 #define MAX_SEEKENTRY_SIZE 21
98 /** per-cuepoint-track - 3 1-byte EBML IDs, 3 1-byte EBML sizes, 2
100 #define MAX_CUETRACKPOS_SIZE 22
102 /** per-cuepoint - 2 1-byte EBML IDs, 2 1-byte EBML sizes, 8-byte uint max */
103 #define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
106 static int ebml_id_size(unsigned int id)
108 return (av_log2(id+1)-1)/7+1;
111 static void put_ebml_id(AVIOContext *pb, unsigned int id)
113 int i = ebml_id_size(id);
115 avio_w8(pb, id >> (i*8));
119 * Write an EBML size meaning "unknown size".
121 * @param bytes The number of bytes the size should occupy (maximum: 8).
123 static void put_ebml_size_unknown(AVIOContext *pb, int bytes)
126 avio_w8(pb, 0x1ff >> bytes);
132 * Calculate how many bytes are needed to represent a given number in EBML.
134 static int ebml_num_size(uint64_t num)
137 while ((num+1) >> bytes*7) bytes++;
142 * Write a number in EBML variable length format.
144 * @param bytes The number of bytes that need to be used to write the number.
145 * If zero, any number of bytes can be used.
147 static void put_ebml_num(AVIOContext *pb, uint64_t num, int bytes)
149 int i, needed_bytes = ebml_num_size(num);
151 // sizes larger than this are currently undefined in EBML
152 assert(num < (1ULL<<56)-1);
155 // don't care how many bytes are used, so use the min
156 bytes = needed_bytes;
157 // the bytes needed to write the given size would exceed the bytes
158 // that we need to use, so write unknown size. This shouldn't happen.
159 assert(bytes >= needed_bytes);
161 num |= 1ULL << bytes*7;
162 for (i = bytes - 1; i >= 0; i--)
163 avio_w8(pb, num >> i*8);
166 static void put_ebml_uint(AVIOContext *pb, unsigned int elementid, uint64_t val)
170 while (tmp>>=8) bytes++;
172 put_ebml_id(pb, elementid);
173 put_ebml_num(pb, bytes, 0);
174 for (i = bytes - 1; i >= 0; i--)
175 avio_w8(pb, val >> i*8);
178 static void put_ebml_float(AVIOContext *pb, unsigned int elementid, double val)
180 put_ebml_id(pb, elementid);
181 put_ebml_num(pb, 8, 0);
182 avio_wb64(pb, av_dbl2int(val));
185 static void put_ebml_binary(AVIOContext *pb, unsigned int elementid,
186 const void *buf, int size)
188 put_ebml_id(pb, elementid);
189 put_ebml_num(pb, size, 0);
190 avio_write(pb, buf, size);
193 static void put_ebml_string(AVIOContext *pb, unsigned int elementid, const char *str)
195 put_ebml_binary(pb, elementid, str, strlen(str));
199 * Write a void element of a given size. Useful for reserving space in
200 * the file to be written to later.
202 * @param size The number of bytes to reserve, which must be at least 2.
204 static void put_ebml_void(AVIOContext *pb, uint64_t size)
206 int64_t currentpos = avio_tell(pb);
210 put_ebml_id(pb, EBML_ID_VOID);
211 // we need to subtract the length needed to store the size from the
212 // size we need to reserve so 2 cases, we use 8 bytes to store the
213 // size if possible, 1 byte otherwise
215 put_ebml_num(pb, size-1, 0);
217 put_ebml_num(pb, size-9, 8);
218 while(avio_tell(pb) < currentpos + size)
222 static ebml_master start_ebml_master(AVIOContext *pb, unsigned int elementid, uint64_t expectedsize)
224 int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
225 put_ebml_id(pb, elementid);
226 put_ebml_size_unknown(pb, bytes);
227 return (ebml_master){ avio_tell(pb), bytes };
230 static void end_ebml_master(AVIOContext *pb, ebml_master master)
232 int64_t pos = avio_tell(pb);
234 if (avio_seek(pb, master.pos - master.sizebytes, SEEK_SET) < 0)
236 put_ebml_num(pb, pos - master.pos, master.sizebytes);
237 avio_seek(pb, pos, SEEK_SET);
240 static void put_xiph_size(AVIOContext *pb, int size)
243 for (i = 0; i < size / 255; i++)
245 avio_w8(pb, size % 255);
249 * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
250 * elements. If a maximum number of elements is specified, enough space
251 * will be reserved at the current file location to write a seek head of
254 * @param segment_offset The absolute offset to the position in the file
255 * where the segment begins.
256 * @param numelements The maximum number of elements that will be indexed
257 * by this seek head, 0 if unlimited.
259 static mkv_seekhead * mkv_start_seekhead(AVIOContext *pb, int64_t segment_offset, int numelements)
261 mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
262 if (new_seekhead == NULL)
265 new_seekhead->segment_offset = segment_offset;
267 if (numelements > 0) {
268 new_seekhead->filepos = avio_tell(pb);
269 // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
270 // and size, and 3 bytes to guarantee that an EBML void element
271 // will fit afterwards
272 new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
273 new_seekhead->max_entries = numelements;
274 put_ebml_void(pb, new_seekhead->reserved_size);
279 static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
281 mkv_seekhead_entry *entries = seekhead->entries;
283 // don't store more elements than we reserved space for
284 if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
287 entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
289 return AVERROR(ENOMEM);
291 entries[seekhead->num_entries ].elementid = elementid;
292 entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
294 seekhead->entries = entries;
299 * Write the seek head to the file and free it. If a maximum number of
300 * elements was specified to mkv_start_seekhead(), the seek head will
301 * be written at the location reserved for it. Otherwise, it is written
302 * at the current location in the file.
304 * @return The file offset where the seekhead was written,
305 * -1 if an error occurred.
307 static int64_t mkv_write_seekhead(AVIOContext *pb, mkv_seekhead *seekhead)
309 ebml_master metaseek, seekentry;
313 currentpos = avio_tell(pb);
315 if (seekhead->reserved_size > 0)
316 if (avio_seek(pb, seekhead->filepos, SEEK_SET) < 0)
319 metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
320 for (i = 0; i < seekhead->num_entries; i++) {
321 mkv_seekhead_entry *entry = &seekhead->entries[i];
323 seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
325 put_ebml_id(pb, MATROSKA_ID_SEEKID);
326 put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
327 put_ebml_id(pb, entry->elementid);
329 put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
330 end_ebml_master(pb, seekentry);
332 end_ebml_master(pb, metaseek);
334 if (seekhead->reserved_size > 0) {
335 uint64_t remaining = seekhead->filepos + seekhead->reserved_size - avio_tell(pb);
336 put_ebml_void(pb, remaining);
337 avio_seek(pb, currentpos, SEEK_SET);
339 currentpos = seekhead->filepos;
341 av_free(seekhead->entries);
347 static mkv_cues * mkv_start_cues(int64_t segment_offset)
349 mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
353 cues->segment_offset = segment_offset;
357 static int mkv_add_cuepoint(mkv_cues *cues, int stream, int64_t ts, int64_t cluster_pos)
359 mkv_cuepoint *entries = cues->entries;
361 entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
363 return AVERROR(ENOMEM);
368 entries[cues->num_entries ].pts = ts;
369 entries[cues->num_entries ].tracknum = stream + 1;
370 entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
372 cues->entries = entries;
376 static int64_t mkv_write_cues(AVIOContext *pb, mkv_cues *cues, int num_tracks)
378 ebml_master cues_element;
382 currentpos = avio_tell(pb);
383 cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
385 for (i = 0; i < cues->num_entries; i++) {
386 ebml_master cuepoint, track_positions;
387 mkv_cuepoint *entry = &cues->entries[i];
388 uint64_t pts = entry->pts;
390 cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
391 put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
393 // put all the entries from different tracks that have the exact same
394 // timestamp into the same CuePoint
395 for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
396 track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
397 put_ebml_uint(pb, MATROSKA_ID_CUETRACK , entry[j].tracknum );
398 put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
399 end_ebml_master(pb, track_positions);
402 end_ebml_master(pb, cuepoint);
404 end_ebml_master(pb, cues_element);
406 av_free(cues->entries);
411 static int put_xiph_codecpriv(AVFormatContext *s, AVIOContext *pb, AVCodecContext *codec)
413 uint8_t *header_start[3];
415 int first_header_size;
418 if (codec->codec_id == CODEC_ID_VORBIS)
419 first_header_size = 30;
421 first_header_size = 42;
423 if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
424 first_header_size, header_start, header_len) < 0) {
425 av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
429 avio_w8(pb, 2); // number packets - 1
430 for (j = 0; j < 2; j++) {
431 put_xiph_size(pb, header_len[j]);
433 for (j = 0; j < 3; j++)
434 avio_write(pb, header_start[j], header_len[j]);
439 static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
441 MPEG4AudioConfig mp4ac;
443 if (ff_mpeg4audio_get_config(&mp4ac, codec->extradata, codec->extradata_size) < 0) {
444 av_log(s, AV_LOG_WARNING, "Error parsing AAC extradata, unable to determine samplerate.\n");
448 *sample_rate = mp4ac.sample_rate;
449 *output_sample_rate = mp4ac.ext_sample_rate;
452 static int mkv_write_codecprivate(AVFormatContext *s, AVIOContext *pb, AVCodecContext *codec, int native_id, int qt_id)
456 int ret, codecpriv_size;
458 ret = avio_open_dyn_buf(&dyn_cp);
463 if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA)
464 ret = put_xiph_codecpriv(s, dyn_cp, codec);
465 else if (codec->codec_id == CODEC_ID_FLAC)
466 ret = ff_flac_write_header(dyn_cp, codec, 1);
467 else if (codec->codec_id == CODEC_ID_H264)
468 ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
469 else if (codec->extradata_size)
470 avio_write(dyn_cp, codec->extradata, codec->extradata_size);
471 } else if (codec->codec_type == AVMEDIA_TYPE_VIDEO) {
473 if (!codec->codec_tag)
474 codec->codec_tag = ff_codec_get_tag(codec_movvideo_tags, codec->codec_id);
475 if (codec->extradata_size)
476 avio_write(dyn_cp, codec->extradata, codec->extradata_size);
478 if (!codec->codec_tag)
479 codec->codec_tag = ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id);
480 if (!codec->codec_tag) {
481 av_log(s, AV_LOG_ERROR, "No bmp codec ID found.\n");
485 ff_put_bmp_header(dyn_cp, codec, ff_codec_bmp_tags, 0);
488 } else if (codec->codec_type == AVMEDIA_TYPE_AUDIO) {
490 tag = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);
492 av_log(s, AV_LOG_ERROR, "No wav codec ID found.\n");
495 if (!codec->codec_tag)
496 codec->codec_tag = tag;
498 ff_put_wav_header(dyn_cp, codec);
501 codecpriv_size = avio_close_dyn_buf(dyn_cp, &codecpriv);
503 put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
508 static int mkv_write_tracks(AVFormatContext *s)
510 MatroskaMuxContext *mkv = s->priv_data;
511 AVIOContext *pb = s->pb;
515 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, avio_tell(pb));
516 if (ret < 0) return ret;
518 tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
519 for (i = 0; i < s->nb_streams; i++) {
520 AVStream *st = s->streams[i];
521 AVCodecContext *codec = st->codec;
522 ebml_master subinfo, track;
525 int bit_depth = av_get_bits_per_sample(codec->codec_id);
526 int sample_rate = codec->sample_rate;
527 int output_sample_rate = 0;
531 bit_depth = av_get_bits_per_sample_fmt(codec->sample_fmt);
533 if (codec->codec_id == CODEC_ID_AAC)
534 get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
536 track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
537 put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
538 put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
539 put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
541 if ((tag = av_metadata_get(st->metadata, "title", NULL, 0)))
542 put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
543 tag = av_metadata_get(st->metadata, "language", NULL, 0);
544 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
547 put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
549 // look for a codec ID string specific to mkv to use,
550 // if none are found, use AVI codes
551 for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
552 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
553 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
559 if (mkv->mode == MODE_WEBM && !(codec->codec_id == CODEC_ID_VP8 ||
560 codec->codec_id == CODEC_ID_VORBIS)) {
561 av_log(s, AV_LOG_ERROR,
562 "Only VP8 video and Vorbis audio are supported for WebM.\n");
563 return AVERROR(EINVAL);
566 switch (codec->codec_type) {
567 case AVMEDIA_TYPE_VIDEO:
568 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
569 put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, av_q2d(codec->time_base)*1E9);
572 ff_codec_get_tag(codec_movvideo_tags, codec->codec_id) &&
573 (!ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id)
574 || codec->codec_id == CODEC_ID_SVQ1
575 || codec->codec_id == CODEC_ID_SVQ3
576 || codec->codec_id == CODEC_ID_CINEPAK))
580 put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
581 else if (!native_id) {
582 // if there is no mkv-specific codec ID, use VFW mode
583 put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
584 mkv->tracks[i].write_dts = 1;
587 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
588 // XXX: interlace flag?
589 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
590 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
591 if (st->sample_aspect_ratio.num) {
592 int d_width = codec->width*av_q2d(st->sample_aspect_ratio);
593 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width);
594 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height);
595 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYUNIT, 3);
597 end_ebml_master(pb, subinfo);
600 case AVMEDIA_TYPE_AUDIO:
601 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
604 // no mkv-specific ID, use ACM mode
605 put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
607 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
608 put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
609 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
610 if (output_sample_rate)
611 put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
613 put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
614 end_ebml_master(pb, subinfo);
617 case AVMEDIA_TYPE_SUBTITLE:
618 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
620 av_log(s, AV_LOG_ERROR, "Subtitle codec %d is not supported.\n", codec->codec_id);
621 return AVERROR_NOTSUPP;
625 av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.\n");
628 ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
629 if (ret < 0) return ret;
631 end_ebml_master(pb, track);
633 // ms precision is the de-facto standard timescale for mkv files
634 av_set_pts_info(st, 64, 1, 1000);
636 end_ebml_master(pb, tracks);
640 static int mkv_write_chapters(AVFormatContext *s)
642 MatroskaMuxContext *mkv = s->priv_data;
643 AVIOContext *pb = s->pb;
644 ebml_master chapters, editionentry;
645 AVRational scale = {1, 1E9};
651 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CHAPTERS, avio_tell(pb));
652 if (ret < 0) return ret;
654 chapters = start_ebml_master(pb, MATROSKA_ID_CHAPTERS , 0);
655 editionentry = start_ebml_master(pb, MATROSKA_ID_EDITIONENTRY, 0);
656 put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGDEFAULT, 1);
657 put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGHIDDEN , 0);
658 for (i = 0; i < s->nb_chapters; i++) {
659 ebml_master chapteratom, chapterdisplay;
660 AVChapter *c = s->chapters[i];
661 AVMetadataTag *t = NULL;
663 chapteratom = start_ebml_master(pb, MATROSKA_ID_CHAPTERATOM, 0);
664 put_ebml_uint(pb, MATROSKA_ID_CHAPTERUID, c->id);
665 put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMESTART,
666 av_rescale_q(c->start, c->time_base, scale));
667 put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMEEND,
668 av_rescale_q(c->end, c->time_base, scale));
669 put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGHIDDEN , 0);
670 put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGENABLED, 1);
671 if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {
672 chapterdisplay = start_ebml_master(pb, MATROSKA_ID_CHAPTERDISPLAY, 0);
673 put_ebml_string(pb, MATROSKA_ID_CHAPSTRING, t->value);
674 put_ebml_string(pb, MATROSKA_ID_CHAPLANG , "und");
675 end_ebml_master(pb, chapterdisplay);
677 end_ebml_master(pb, chapteratom);
679 end_ebml_master(pb, editionentry);
680 end_ebml_master(pb, chapters);
684 static void mkv_write_simpletag(AVIOContext *pb, AVMetadataTag *t)
686 uint8_t *key = av_strdup(t->key);
688 const uint8_t *lang = NULL;
691 if ((p = strrchr(p, '-')) &&
692 (lang = av_convert_lang_to(p + 1, AV_LANG_ISO639_2_BIBL)))
699 else if (*p >= 'a' && *p <= 'z')
704 tag = start_ebml_master(pb, MATROSKA_ID_SIMPLETAG, 0);
705 put_ebml_string(pb, MATROSKA_ID_TAGNAME, key);
707 put_ebml_string(pb, MATROSKA_ID_TAGLANG, lang);
708 put_ebml_string(pb, MATROSKA_ID_TAGSTRING, t->value);
709 end_ebml_master(pb, tag);
714 static int mkv_write_tag(AVFormatContext *s, AVMetadata *m, unsigned int elementid,
715 unsigned int uid, ebml_master *tags)
717 MatroskaMuxContext *mkv = s->priv_data;
718 ebml_master tag, targets;
719 AVMetadataTag *t = NULL;
723 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TAGS, avio_tell(s->pb));
724 if (ret < 0) return ret;
726 *tags = start_ebml_master(s->pb, MATROSKA_ID_TAGS, 0);
729 tag = start_ebml_master(s->pb, MATROSKA_ID_TAG, 0);
730 targets = start_ebml_master(s->pb, MATROSKA_ID_TAGTARGETS, 0);
732 put_ebml_uint(s->pb, elementid, uid);
733 end_ebml_master(s->pb, targets);
735 while ((t = av_metadata_get(m, "", t, AV_METADATA_IGNORE_SUFFIX)))
736 if (strcasecmp(t->key, "title"))
737 mkv_write_simpletag(s->pb, t);
739 end_ebml_master(s->pb, tag);
743 static int mkv_write_tags(AVFormatContext *s)
745 ebml_master tags = {0};
748 ff_metadata_conv_ctx(s, ff_mkv_metadata_conv, NULL);
750 if (av_metadata_get(s->metadata, "", NULL, AV_METADATA_IGNORE_SUFFIX)) {
751 ret = mkv_write_tag(s, s->metadata, 0, 0, &tags);
752 if (ret < 0) return ret;
755 for (i = 0; i < s->nb_streams; i++) {
756 AVStream *st = s->streams[i];
758 if (!av_metadata_get(st->metadata, "", 0, AV_METADATA_IGNORE_SUFFIX))
761 ret = mkv_write_tag(s, st->metadata, MATROSKA_ID_TAGTARGETS_TRACKUID, i + 1, &tags);
762 if (ret < 0) return ret;
765 for (i = 0; i < s->nb_chapters; i++) {
766 AVChapter *ch = s->chapters[i];
768 if (!av_metadata_get(ch->metadata, "", NULL, AV_METADATA_IGNORE_SUFFIX))
771 ret = mkv_write_tag(s, ch->metadata, MATROSKA_ID_TAGTARGETS_CHAPTERUID, ch->id, &tags);
772 if (ret < 0) return ret;
776 end_ebml_master(s->pb, tags);
780 static int mkv_write_header(AVFormatContext *s)
782 MatroskaMuxContext *mkv = s->priv_data;
783 AVIOContext *pb = s->pb;
784 ebml_master ebml_header, segment_info;
788 if (!strcmp(s->oformat->name, "webm")) mkv->mode = MODE_WEBM;
789 else mkv->mode = MODE_MATROSKAv2;
791 mkv->tracks = av_mallocz(s->nb_streams * sizeof(*mkv->tracks));
793 return AVERROR(ENOMEM);
795 ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
796 put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
797 put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
798 put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
799 put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
800 put_ebml_string (pb, EBML_ID_DOCTYPE , s->oformat->name);
801 put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2);
802 put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2);
803 end_ebml_master(pb, ebml_header);
805 mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
806 mkv->segment_offset = avio_tell(pb);
808 // we write 2 seek heads - one at the end of the file to point to each
809 // cluster, and one at the beginning to point to all other level one
810 // elements (including the seek head at the end of the file), which
811 // isn't more than 10 elements if we only write one of each other
812 // currently defined level 1 element
813 mkv->main_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 10);
814 if (!mkv->main_seekhead)
815 return AVERROR(ENOMEM);
817 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, avio_tell(pb));
818 if (ret < 0) return ret;
820 segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
821 put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
822 if ((tag = av_metadata_get(s->metadata, "title", NULL, 0)))
823 put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
824 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
825 uint32_t segment_uid[4];
828 av_lfg_init(&lfg, av_get_random_seed());
830 for (i = 0; i < 4; i++)
831 segment_uid[i] = av_lfg_get(&lfg);
833 put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
834 put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
835 put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
838 // reserve space for the duration
840 mkv->duration_offset = avio_tell(pb);
841 put_ebml_void(pb, 11); // assumes double-precision float to be written
842 end_ebml_master(pb, segment_info);
844 ret = mkv_write_tracks(s);
845 if (ret < 0) return ret;
847 if (mkv->mode != MODE_WEBM) {
848 ret = mkv_write_chapters(s);
849 if (ret < 0) return ret;
851 ret = mkv_write_tags(s);
852 if (ret < 0) return ret;
855 if (!s->pb->seekable)
856 mkv_write_seekhead(pb, mkv->main_seekhead);
858 mkv->cues = mkv_start_cues(mkv->segment_offset);
859 if (mkv->cues == NULL)
860 return AVERROR(ENOMEM);
862 av_init_packet(&mkv->cur_audio_pkt);
863 mkv->cur_audio_pkt.size = 0;
864 mkv->audio_buffer_size = 0;
870 static int mkv_blockgroup_size(int pkt_size)
872 int size = pkt_size + 4;
873 size += ebml_num_size(size);
874 size += 2; // EBML ID for block and block duration
875 size += 8; // max size of block duration
876 size += ebml_num_size(size);
877 size += 1; // blockgroup EBML ID
881 static int ass_get_duration(const uint8_t *p)
883 int sh, sm, ss, sc, eh, em, es, ec;
886 if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
887 &sh, &sm, &ss, &sc, &eh, &em, &es, &ec) != 8)
889 start = 3600000*sh + 60000*sm + 1000*ss + 10*sc;
890 end = 3600000*eh + 60000*em + 1000*es + 10*ec;
894 static int mkv_write_ass_blocks(AVFormatContext *s, AVIOContext *pb, AVPacket *pkt)
896 MatroskaMuxContext *mkv = s->priv_data;
897 int i, layer = 0, max_duration = 0, size, line_size, data_size = pkt->size;
898 uint8_t *start, *end, *data = pkt->data;
899 ebml_master blockgroup;
903 int duration = ass_get_duration(data);
904 max_duration = FFMAX(duration, max_duration);
905 end = memchr(data, '\n', data_size);
906 size = line_size = end ? end-data+1 : data_size;
907 size -= end ? (end[-1]=='\r')+1 : 0;
909 for (i=0; i<3; i++, start++)
910 if (!(start = memchr(start, ',', size-(start-data))))
912 size -= start - data;
913 sscanf(data, "Dialogue: %d,", &layer);
914 i = snprintf(buffer, sizeof(buffer), "%"PRId64",%d,",
915 s->streams[pkt->stream_index]->nb_frames++, layer);
916 size = FFMIN(i+size, sizeof(buffer));
917 memcpy(buffer+i, start, size-i);
919 av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
920 "pts %" PRId64 ", duration %d\n",
921 avio_tell(pb), size, pkt->pts, duration);
922 blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
923 put_ebml_id(pb, MATROSKA_ID_BLOCK);
924 put_ebml_num(pb, size+4, 0);
925 avio_w8(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
926 avio_wb16(pb, pkt->pts - mkv->cluster_pts);
928 avio_write(pb, buffer, size);
929 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
930 end_ebml_master(pb, blockgroup);
933 data_size -= line_size;
939 static void mkv_write_block(AVFormatContext *s, AVIOContext *pb,
940 unsigned int blockid, AVPacket *pkt, int flags)
942 MatroskaMuxContext *mkv = s->priv_data;
943 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
944 uint8_t *data = NULL;
945 int size = pkt->size;
946 int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
948 av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
949 "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
950 avio_tell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
951 if (codec->codec_id == CODEC_ID_H264 && codec->extradata_size > 0 &&
952 (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
953 ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
956 put_ebml_id(pb, blockid);
957 put_ebml_num(pb, size+4, 0);
958 avio_w8(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
959 avio_wb16(pb, ts - mkv->cluster_pts);
961 avio_write(pb, data, size);
962 if (data != pkt->data)
966 static int srt_get_duration(uint8_t **buf)
970 for (i=0; i<2 && !duration; i++) {
971 int s_hour, s_min, s_sec, s_hsec, e_hour, e_min, e_sec, e_hsec;
972 if (sscanf(*buf, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d",
973 &s_hour, &s_min, &s_sec, &s_hsec,
974 &e_hour, &e_min, &e_sec, &e_hsec) == 8) {
975 s_min += 60*s_hour; e_min += 60*e_hour;
976 s_sec += 60*s_min; e_sec += 60*e_min;
977 s_hsec += 1000*s_sec; e_hsec += 1000*e_sec;
978 duration = e_hsec - s_hsec;
980 *buf += strcspn(*buf, "\n") + 1;
985 static int mkv_write_srt_blocks(AVFormatContext *s, AVIOContext *pb, AVPacket *pkt)
987 ebml_master blockgroup;
988 AVPacket pkt2 = *pkt;
989 int64_t duration = srt_get_duration(&pkt2.data);
990 pkt2.size -= pkt2.data - pkt->data;
992 blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP,
993 mkv_blockgroup_size(pkt2.size));
994 mkv_write_block(s, pb, MATROSKA_ID_BLOCK, &pkt2, 0);
995 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
996 end_ebml_master(pb, blockgroup);
1001 static void mkv_flush_dynbuf(AVFormatContext *s)
1003 MatroskaMuxContext *mkv = s->priv_data;
1010 bufsize = avio_close_dyn_buf(mkv->dyn_bc, &dyn_buf);
1011 avio_write(s->pb, dyn_buf, bufsize);
1016 static int mkv_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
1018 MatroskaMuxContext *mkv = s->priv_data;
1019 AVIOContext *pb = s->pb;
1020 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
1021 int keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
1022 int duration = pkt->duration;
1024 int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
1026 if (ts == AV_NOPTS_VALUE) {
1027 av_log(s, AV_LOG_ERROR, "Can't write packet with unknown timestamp\n");
1028 return AVERROR(EINVAL);
1031 if (!s->pb->seekable) {
1033 avio_open_dyn_buf(&mkv->dyn_bc);
1037 if (!mkv->cluster_pos) {
1038 mkv->cluster_pos = avio_tell(s->pb);
1039 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
1040 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, FFMAX(0, ts));
1041 mkv->cluster_pts = FFMAX(0, ts);
1044 if (codec->codec_type != AVMEDIA_TYPE_SUBTITLE) {
1045 mkv_write_block(s, pb, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
1046 } else if (codec->codec_id == CODEC_ID_SSA) {
1047 duration = mkv_write_ass_blocks(s, pb, pkt);
1048 } else if (codec->codec_id == CODEC_ID_SRT) {
1049 duration = mkv_write_srt_blocks(s, pb, pkt);
1051 ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
1052 duration = pkt->convergence_duration;
1053 mkv_write_block(s, pb, MATROSKA_ID_BLOCK, pkt, 0);
1054 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
1055 end_ebml_master(pb, blockgroup);
1058 if (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe) {
1059 ret = mkv_add_cuepoint(mkv->cues, pkt->stream_index, ts, mkv->cluster_pos);
1060 if (ret < 0) return ret;
1063 mkv->duration = FFMAX(mkv->duration, ts + duration);
1067 static int mkv_copy_packet(MatroskaMuxContext *mkv, const AVPacket *pkt)
1069 uint8_t *data = mkv->cur_audio_pkt.data;
1070 mkv->cur_audio_pkt = *pkt;
1071 mkv->cur_audio_pkt.data = av_fast_realloc(data, &mkv->audio_buffer_size, pkt->size);
1072 if (!mkv->cur_audio_pkt.data)
1073 return AVERROR(ENOMEM);
1075 memcpy(mkv->cur_audio_pkt.data, pkt->data, pkt->size);
1076 mkv->cur_audio_pkt.size = pkt->size;
1080 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
1082 MatroskaMuxContext *mkv = s->priv_data;
1083 AVIOContext *pb = s->pb->seekable ? s->pb : mkv->dyn_bc;
1084 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
1085 int ret, keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
1086 int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
1087 int cluster_size = avio_tell(pb) - (s->pb->seekable ? mkv->cluster_pos : 0);
1089 // start a new cluster every 5 MB or 5 sec, or 32k / 1 sec for streaming or
1090 // after 4k and on a keyframe
1091 if (mkv->cluster_pos &&
1092 ((!s->pb->seekable && (cluster_size > 32*1024 || ts > mkv->cluster_pts + 1000))
1093 || cluster_size > 5*1024*1024 || ts > mkv->cluster_pts + 5000
1094 || (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe && cluster_size > 4*1024))) {
1095 av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
1096 " bytes, pts %" PRIu64 "\n", avio_tell(pb), ts);
1097 end_ebml_master(pb, mkv->cluster);
1098 mkv->cluster_pos = 0;
1100 mkv_flush_dynbuf(s);
1103 // check if we have an audio packet cached
1104 if (mkv->cur_audio_pkt.size > 0) {
1105 ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
1106 mkv->cur_audio_pkt.size = 0;
1108 av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
1113 // buffer an audio packet to ensure the packet containing the video
1114 // keyframe's timecode is contained in the same cluster for WebM
1115 if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
1116 ret = mkv_copy_packet(mkv, pkt);
1118 ret = mkv_write_packet_internal(s, pkt);
1122 static int mkv_write_trailer(AVFormatContext *s)
1124 MatroskaMuxContext *mkv = s->priv_data;
1125 AVIOContext *pb = s->pb;
1126 int64_t currentpos, cuespos;
1129 // check if we have an audio packet cached
1130 if (mkv->cur_audio_pkt.size > 0) {
1131 ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
1132 mkv->cur_audio_pkt.size = 0;
1134 av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
1140 end_ebml_master(mkv->dyn_bc, mkv->cluster);
1141 mkv_flush_dynbuf(s);
1142 } else if (mkv->cluster_pos) {
1143 end_ebml_master(pb, mkv->cluster);
1147 if (mkv->cues->num_entries) {
1148 cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
1150 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES, cuespos);
1151 if (ret < 0) return ret;
1154 mkv_write_seekhead(pb, mkv->main_seekhead);
1156 // update the duration
1157 av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
1158 currentpos = avio_tell(pb);
1159 avio_seek(pb, mkv->duration_offset, SEEK_SET);
1160 put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
1162 avio_seek(pb, currentpos, SEEK_SET);
1165 end_ebml_master(pb, mkv->segment);
1166 av_free(mkv->tracks);
1167 av_destruct_packet(&mkv->cur_audio_pkt);
1172 #if CONFIG_MATROSKA_MUXER
1173 AVOutputFormat ff_matroska_muxer = {
1175 NULL_IF_CONFIG_SMALL("Matroska file format"),
1178 sizeof(MatroskaMuxContext),
1184 .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
1185 .codec_tag = (const AVCodecTag* const []){ff_codec_bmp_tags, ff_codec_wav_tags, 0},
1186 .subtitle_codec = CODEC_ID_TEXT,
1190 #if CONFIG_WEBM_MUXER
1191 AVOutputFormat ff_webm_muxer = {
1193 NULL_IF_CONFIG_SMALL("WebM file format"),
1196 sizeof(MatroskaMuxContext),
1202 .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
1206 #if CONFIG_MATROSKA_AUDIO_MUXER
1207 AVOutputFormat ff_matroska_audio_muxer = {
1209 NULL_IF_CONFIG_SMALL("Matroska file format"),
1212 sizeof(MatroskaMuxContext),
1218 .flags = AVFMT_GLOBALHEADER,
1219 .codec_tag = (const AVCodecTag* const []){ff_codec_wav_tags, 0},