3 * Copyright (c) 2007 David Conrad
5 * This file is part of Libav.
7 * Libav 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 * Libav 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 Libav; 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/intfloat_readwrite.h"
32 #include "libavutil/mathematics.h"
33 #include "libavutil/random_seed.h"
34 #include "libavutil/lfg.h"
35 #include "libavutil/dict.h"
36 #include "libavutil/avstring.h"
37 #include "libavcodec/xiph.h"
38 #include "libavcodec/mpeg4audio.h"
40 typedef struct ebml_master {
41 int64_t pos; ///< absolute offset in the file where the master's elements start
42 int sizebytes; ///< how many bytes were reserved for the size
45 typedef struct mkv_seekhead_entry {
46 unsigned int elementid;
50 typedef struct mkv_seekhead {
52 int64_t segment_offset; ///< the file offset to the beginning of the segment
53 int reserved_size; ///< -1 if appending to file
55 mkv_seekhead_entry *entries;
62 int64_t cluster_pos; ///< file offset of the cluster containing the block
66 int64_t segment_offset;
67 mkv_cuepoint *entries;
75 #define MODE_MATROSKAv2 0x01
76 #define MODE_WEBM 0x02
78 typedef struct MatroskaMuxContext {
82 int64_t segment_offset;
84 int64_t cluster_pos; ///< file offset of the current cluster
86 int64_t duration_offset;
88 mkv_seekhead *main_seekhead;
92 unsigned int audio_buffer_size;
93 AVPacket cur_audio_pkt;
99 /** 2 bytes * 3 for EBML IDs, 3 1-byte EBML lengths, 8 bytes for 64 bit
100 * offset, 4 bytes for target EBML ID */
101 #define MAX_SEEKENTRY_SIZE 21
103 /** per-cuepoint-track - 3 1-byte EBML IDs, 3 1-byte EBML sizes, 2
105 #define MAX_CUETRACKPOS_SIZE 22
107 /** per-cuepoint - 2 1-byte EBML IDs, 2 1-byte EBML sizes, 8-byte uint max */
108 #define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
111 static int ebml_id_size(unsigned int id)
113 return (av_log2(id+1)-1)/7+1;
116 static void put_ebml_id(AVIOContext *pb, unsigned int id)
118 int i = ebml_id_size(id);
120 avio_w8(pb, id >> (i*8));
124 * Write an EBML size meaning "unknown size".
126 * @param bytes The number of bytes the size should occupy (maximum: 8).
128 static void put_ebml_size_unknown(AVIOContext *pb, int bytes)
131 avio_w8(pb, 0x1ff >> bytes);
137 * Calculate how many bytes are needed to represent a given number in EBML.
139 static int ebml_num_size(uint64_t num)
142 while ((num+1) >> bytes*7) bytes++;
147 * Write a number in EBML variable length format.
149 * @param bytes The number of bytes that need to be used to write the number.
150 * If zero, any number of bytes can be used.
152 static void put_ebml_num(AVIOContext *pb, uint64_t num, int bytes)
154 int i, needed_bytes = ebml_num_size(num);
156 // sizes larger than this are currently undefined in EBML
157 assert(num < (1ULL<<56)-1);
160 // don't care how many bytes are used, so use the min
161 bytes = needed_bytes;
162 // the bytes needed to write the given size would exceed the bytes
163 // that we need to use, so write unknown size. This shouldn't happen.
164 assert(bytes >= needed_bytes);
166 num |= 1ULL << bytes*7;
167 for (i = bytes - 1; i >= 0; i--)
168 avio_w8(pb, num >> i*8);
171 static void put_ebml_uint(AVIOContext *pb, unsigned int elementid, uint64_t val)
175 while (tmp>>=8) bytes++;
177 put_ebml_id(pb, elementid);
178 put_ebml_num(pb, bytes, 0);
179 for (i = bytes - 1; i >= 0; i--)
180 avio_w8(pb, val >> i*8);
183 static void put_ebml_float(AVIOContext *pb, unsigned int elementid, double val)
185 put_ebml_id(pb, elementid);
186 put_ebml_num(pb, 8, 0);
187 avio_wb64(pb, av_dbl2int(val));
190 static void put_ebml_binary(AVIOContext *pb, unsigned int elementid,
191 const void *buf, int size)
193 put_ebml_id(pb, elementid);
194 put_ebml_num(pb, size, 0);
195 avio_write(pb, buf, size);
198 static void put_ebml_string(AVIOContext *pb, unsigned int elementid, const char *str)
200 put_ebml_binary(pb, elementid, str, strlen(str));
204 * Write a void element of a given size. Useful for reserving space in
205 * the file to be written to later.
207 * @param size The number of bytes to reserve, which must be at least 2.
209 static void put_ebml_void(AVIOContext *pb, uint64_t size)
211 int64_t currentpos = avio_tell(pb);
215 put_ebml_id(pb, EBML_ID_VOID);
216 // we need to subtract the length needed to store the size from the
217 // size we need to reserve so 2 cases, we use 8 bytes to store the
218 // size if possible, 1 byte otherwise
220 put_ebml_num(pb, size-1, 0);
222 put_ebml_num(pb, size-9, 8);
223 while(avio_tell(pb) < currentpos + size)
227 static ebml_master start_ebml_master(AVIOContext *pb, unsigned int elementid, uint64_t expectedsize)
229 int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
230 put_ebml_id(pb, elementid);
231 put_ebml_size_unknown(pb, bytes);
232 return (ebml_master){ avio_tell(pb), bytes };
235 static void end_ebml_master(AVIOContext *pb, ebml_master master)
237 int64_t pos = avio_tell(pb);
239 if (avio_seek(pb, master.pos - master.sizebytes, SEEK_SET) < 0)
241 put_ebml_num(pb, pos - master.pos, master.sizebytes);
242 avio_seek(pb, pos, SEEK_SET);
245 static void put_xiph_size(AVIOContext *pb, int size)
248 for (i = 0; i < size / 255; i++)
250 avio_w8(pb, size % 255);
254 * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
255 * elements. If a maximum number of elements is specified, enough space
256 * will be reserved at the current file location to write a seek head of
259 * @param segment_offset The absolute offset to the position in the file
260 * where the segment begins.
261 * @param numelements The maximum number of elements that will be indexed
262 * by this seek head, 0 if unlimited.
264 static mkv_seekhead * mkv_start_seekhead(AVIOContext *pb, int64_t segment_offset, int numelements)
266 mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
267 if (new_seekhead == NULL)
270 new_seekhead->segment_offset = segment_offset;
272 if (numelements > 0) {
273 new_seekhead->filepos = avio_tell(pb);
274 // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
275 // and size, and 3 bytes to guarantee that an EBML void element
276 // will fit afterwards
277 new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
278 new_seekhead->max_entries = numelements;
279 put_ebml_void(pb, new_seekhead->reserved_size);
284 static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
286 mkv_seekhead_entry *entries = seekhead->entries;
288 // don't store more elements than we reserved space for
289 if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
292 entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
294 return AVERROR(ENOMEM);
296 entries[seekhead->num_entries ].elementid = elementid;
297 entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
299 seekhead->entries = entries;
304 * Write the seek head to the file and free it. If a maximum number of
305 * elements was specified to mkv_start_seekhead(), the seek head will
306 * be written at the location reserved for it. Otherwise, it is written
307 * at the current location in the file.
309 * @return The file offset where the seekhead was written,
310 * -1 if an error occurred.
312 static int64_t mkv_write_seekhead(AVIOContext *pb, mkv_seekhead *seekhead)
314 ebml_master metaseek, seekentry;
318 currentpos = avio_tell(pb);
320 if (seekhead->reserved_size > 0) {
321 if (avio_seek(pb, seekhead->filepos, SEEK_SET) < 0) {
327 metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
328 for (i = 0; i < seekhead->num_entries; i++) {
329 mkv_seekhead_entry *entry = &seekhead->entries[i];
331 seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
333 put_ebml_id(pb, MATROSKA_ID_SEEKID);
334 put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
335 put_ebml_id(pb, entry->elementid);
337 put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
338 end_ebml_master(pb, seekentry);
340 end_ebml_master(pb, metaseek);
342 if (seekhead->reserved_size > 0) {
343 uint64_t remaining = seekhead->filepos + seekhead->reserved_size - avio_tell(pb);
344 put_ebml_void(pb, remaining);
345 avio_seek(pb, currentpos, SEEK_SET);
347 currentpos = seekhead->filepos;
350 av_free(seekhead->entries);
356 static mkv_cues * mkv_start_cues(int64_t segment_offset)
358 mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
362 cues->segment_offset = segment_offset;
366 static int mkv_add_cuepoint(mkv_cues *cues, int stream, int64_t ts, int64_t cluster_pos)
368 mkv_cuepoint *entries = cues->entries;
370 entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
372 return AVERROR(ENOMEM);
377 entries[cues->num_entries ].pts = ts;
378 entries[cues->num_entries ].tracknum = stream + 1;
379 entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
381 cues->entries = entries;
385 static int64_t mkv_write_cues(AVIOContext *pb, mkv_cues *cues, int num_tracks)
387 ebml_master cues_element;
391 currentpos = avio_tell(pb);
392 cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
394 for (i = 0; i < cues->num_entries; i++) {
395 ebml_master cuepoint, track_positions;
396 mkv_cuepoint *entry = &cues->entries[i];
397 uint64_t pts = entry->pts;
399 cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
400 put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
402 // put all the entries from different tracks that have the exact same
403 // timestamp into the same CuePoint
404 for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
405 track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
406 put_ebml_uint(pb, MATROSKA_ID_CUETRACK , entry[j].tracknum );
407 put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
408 end_ebml_master(pb, track_positions);
411 end_ebml_master(pb, cuepoint);
413 end_ebml_master(pb, cues_element);
418 static int put_xiph_codecpriv(AVFormatContext *s, AVIOContext *pb, AVCodecContext *codec)
420 uint8_t *header_start[3];
422 int first_header_size;
425 if (codec->codec_id == CODEC_ID_VORBIS)
426 first_header_size = 30;
428 first_header_size = 42;
430 if (avpriv_split_xiph_headers(codec->extradata, codec->extradata_size,
431 first_header_size, header_start, header_len) < 0) {
432 av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
436 avio_w8(pb, 2); // number packets - 1
437 for (j = 0; j < 2; j++) {
438 put_xiph_size(pb, header_len[j]);
440 for (j = 0; j < 3; j++)
441 avio_write(pb, header_start[j], header_len[j]);
446 static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
448 MPEG4AudioConfig mp4ac;
450 if (avpriv_mpeg4audio_get_config(&mp4ac, codec->extradata, codec->extradata_size) < 0) {
451 av_log(s, AV_LOG_WARNING, "Error parsing AAC extradata, unable to determine samplerate.\n");
455 *sample_rate = mp4ac.sample_rate;
456 *output_sample_rate = mp4ac.ext_sample_rate;
459 static int mkv_write_codecprivate(AVFormatContext *s, AVIOContext *pb, AVCodecContext *codec, int native_id, int qt_id)
463 int ret, codecpriv_size;
465 ret = avio_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 avio_write(dyn_cp, codec->extradata, codec->extradata_size);
478 } else if (codec->codec_type == AVMEDIA_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 avio_write(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 == AVMEDIA_TYPE_AUDIO) {
497 tag = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);
499 av_log(s, AV_LOG_ERROR, "No wav codec ID found.\n");
502 if (!codec->codec_tag)
503 codec->codec_tag = tag;
505 ff_put_wav_header(dyn_cp, codec);
508 codecpriv_size = avio_close_dyn_buf(dyn_cp, &codecpriv);
510 put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
515 static int mkv_write_tracks(AVFormatContext *s)
517 MatroskaMuxContext *mkv = s->priv_data;
518 AVIOContext *pb = s->pb;
522 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, avio_tell(pb));
523 if (ret < 0) return ret;
525 tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
526 for (i = 0; i < s->nb_streams; i++) {
527 AVStream *st = s->streams[i];
528 AVCodecContext *codec = st->codec;
529 ebml_master subinfo, track;
532 int bit_depth = av_get_bits_per_sample(codec->codec_id);
533 int sample_rate = codec->sample_rate;
534 int output_sample_rate = 0;
535 AVDictionaryEntry *tag;
537 if (codec->codec_type == AVMEDIA_TYPE_ATTACHMENT) {
538 mkv->have_attachments = 1;
543 bit_depth = av_get_bytes_per_sample(codec->sample_fmt) << 3;
545 if (codec->codec_id == CODEC_ID_AAC)
546 get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
548 track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
549 put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
550 put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
551 put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
553 if ((tag = av_dict_get(st->metadata, "title", NULL, 0)))
554 put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
555 tag = av_dict_get(st->metadata, "language", NULL, 0);
556 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
559 put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
561 // look for a codec ID string specific to mkv to use,
562 // if none are found, use AVI codes
563 for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
564 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
565 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
571 if (mkv->mode == MODE_WEBM && !(codec->codec_id == CODEC_ID_VP8 ||
572 codec->codec_id == CODEC_ID_VORBIS)) {
573 av_log(s, AV_LOG_ERROR,
574 "Only VP8 video and Vorbis audio are supported for WebM.\n");
575 return AVERROR(EINVAL);
578 switch (codec->codec_type) {
579 case AVMEDIA_TYPE_VIDEO:
580 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
581 put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, av_q2d(codec->time_base)*1E9);
584 ff_codec_get_tag(codec_movvideo_tags, codec->codec_id) &&
585 (!ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id)
586 || codec->codec_id == CODEC_ID_SVQ1
587 || codec->codec_id == CODEC_ID_SVQ3
588 || codec->codec_id == CODEC_ID_CINEPAK))
592 put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
593 else if (!native_id) {
594 // if there is no mkv-specific codec ID, use VFW mode
595 put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
596 mkv->tracks[i].write_dts = 1;
599 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
600 // XXX: interlace flag?
601 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
602 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
603 if ((tag = av_dict_get(s->metadata, "stereo_mode", NULL, 0))) {
604 uint8_t stereo_fmt = atoi(tag->value);
609 if (stereo_fmt <= MATROSKA_VIDEO_STEREOMODE_TYPE_TOP_BOTTOM
610 || stereo_fmt == MATROSKA_VIDEO_STEREOMODE_TYPE_RIGHT_LEFT)
613 case MODE_MATROSKAv2:
614 if (stereo_fmt <= MATROSKA_VIDEO_STEREOMODE_TYPE_BOTH_EYES_BLOCK_RL)
620 put_ebml_uint (pb, MATROSKA_ID_VIDEOSTEREOMODE, stereo_fmt);
622 if (st->sample_aspect_ratio.num) {
623 int d_width = codec->width*av_q2d(st->sample_aspect_ratio);
624 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width);
625 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height);
626 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYUNIT, 3);
628 end_ebml_master(pb, subinfo);
631 case AVMEDIA_TYPE_AUDIO:
632 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
635 // no mkv-specific ID, use ACM mode
636 put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
638 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
639 put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
640 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
641 if (output_sample_rate)
642 put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
644 put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
645 end_ebml_master(pb, subinfo);
648 case AVMEDIA_TYPE_SUBTITLE:
649 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
651 av_log(s, AV_LOG_ERROR, "Subtitle codec %d is not supported.\n", codec->codec_id);
652 return AVERROR(ENOSYS);
656 av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.\n");
659 ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
660 if (ret < 0) return ret;
662 end_ebml_master(pb, track);
664 // ms precision is the de-facto standard timescale for mkv files
665 av_set_pts_info(st, 64, 1, 1000);
667 end_ebml_master(pb, tracks);
671 static int mkv_write_chapters(AVFormatContext *s)
673 MatroskaMuxContext *mkv = s->priv_data;
674 AVIOContext *pb = s->pb;
675 ebml_master chapters, editionentry;
676 AVRational scale = {1, 1E9};
682 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CHAPTERS, avio_tell(pb));
683 if (ret < 0) return ret;
685 chapters = start_ebml_master(pb, MATROSKA_ID_CHAPTERS , 0);
686 editionentry = start_ebml_master(pb, MATROSKA_ID_EDITIONENTRY, 0);
687 put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGDEFAULT, 1);
688 put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGHIDDEN , 0);
689 for (i = 0; i < s->nb_chapters; i++) {
690 ebml_master chapteratom, chapterdisplay;
691 AVChapter *c = s->chapters[i];
692 AVDictionaryEntry *t = NULL;
694 chapteratom = start_ebml_master(pb, MATROSKA_ID_CHAPTERATOM, 0);
695 put_ebml_uint(pb, MATROSKA_ID_CHAPTERUID, c->id);
696 put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMESTART,
697 av_rescale_q(c->start, c->time_base, scale));
698 put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMEEND,
699 av_rescale_q(c->end, c->time_base, scale));
700 put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGHIDDEN , 0);
701 put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGENABLED, 1);
702 if ((t = av_dict_get(c->metadata, "title", NULL, 0))) {
703 chapterdisplay = start_ebml_master(pb, MATROSKA_ID_CHAPTERDISPLAY, 0);
704 put_ebml_string(pb, MATROSKA_ID_CHAPSTRING, t->value);
705 put_ebml_string(pb, MATROSKA_ID_CHAPLANG , "und");
706 end_ebml_master(pb, chapterdisplay);
708 end_ebml_master(pb, chapteratom);
710 end_ebml_master(pb, editionentry);
711 end_ebml_master(pb, chapters);
715 static void mkv_write_simpletag(AVIOContext *pb, AVDictionaryEntry *t)
717 uint8_t *key = av_strdup(t->key);
719 const uint8_t *lang = NULL;
722 if ((p = strrchr(p, '-')) &&
723 (lang = av_convert_lang_to(p + 1, AV_LANG_ISO639_2_BIBL)))
730 else if (*p >= 'a' && *p <= 'z')
735 tag = start_ebml_master(pb, MATROSKA_ID_SIMPLETAG, 0);
736 put_ebml_string(pb, MATROSKA_ID_TAGNAME, key);
738 put_ebml_string(pb, MATROSKA_ID_TAGLANG, lang);
739 put_ebml_string(pb, MATROSKA_ID_TAGSTRING, t->value);
740 end_ebml_master(pb, tag);
745 static int mkv_write_tag(AVFormatContext *s, AVDictionary *m, unsigned int elementid,
746 unsigned int uid, ebml_master *tags)
748 MatroskaMuxContext *mkv = s->priv_data;
749 ebml_master tag, targets;
750 AVDictionaryEntry *t = NULL;
754 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TAGS, avio_tell(s->pb));
755 if (ret < 0) return ret;
757 *tags = start_ebml_master(s->pb, MATROSKA_ID_TAGS, 0);
760 tag = start_ebml_master(s->pb, MATROSKA_ID_TAG, 0);
761 targets = start_ebml_master(s->pb, MATROSKA_ID_TAGTARGETS, 0);
763 put_ebml_uint(s->pb, elementid, uid);
764 end_ebml_master(s->pb, targets);
766 while ((t = av_dict_get(m, "", t, AV_DICT_IGNORE_SUFFIX)))
767 if (av_strcasecmp(t->key, "title"))
768 mkv_write_simpletag(s->pb, t);
770 end_ebml_master(s->pb, tag);
774 static int mkv_write_tags(AVFormatContext *s)
776 ebml_master tags = {0};
779 ff_metadata_conv_ctx(s, ff_mkv_metadata_conv, NULL);
781 if (av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
782 ret = mkv_write_tag(s, s->metadata, 0, 0, &tags);
783 if (ret < 0) return ret;
786 for (i = 0; i < s->nb_streams; i++) {
787 AVStream *st = s->streams[i];
789 if (!av_dict_get(st->metadata, "", 0, AV_DICT_IGNORE_SUFFIX))
792 ret = mkv_write_tag(s, st->metadata, MATROSKA_ID_TAGTARGETS_TRACKUID, i + 1, &tags);
793 if (ret < 0) return ret;
796 for (i = 0; i < s->nb_chapters; i++) {
797 AVChapter *ch = s->chapters[i];
799 if (!av_dict_get(ch->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX))
802 ret = mkv_write_tag(s, ch->metadata, MATROSKA_ID_TAGTARGETS_CHAPTERUID, ch->id, &tags);
803 if (ret < 0) return ret;
807 end_ebml_master(s->pb, tags);
811 static int mkv_write_attachments(AVFormatContext *s)
813 MatroskaMuxContext *mkv = s->priv_data;
814 AVIOContext *pb = s->pb;
815 ebml_master attachments;
819 if (!mkv->have_attachments)
822 av_lfg_init(&c, av_get_random_seed());
824 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_ATTACHMENTS, avio_tell(pb));
825 if (ret < 0) return ret;
827 attachments = start_ebml_master(pb, MATROSKA_ID_ATTACHMENTS, 0);
829 for (i = 0; i < s->nb_streams; i++) {
830 AVStream *st = s->streams[i];
831 ebml_master attached_file;
832 AVDictionaryEntry *t;
833 const char *mimetype = NULL;
835 if (st->codec->codec_type != AVMEDIA_TYPE_ATTACHMENT)
838 attached_file = start_ebml_master(pb, MATROSKA_ID_ATTACHEDFILE, 0);
840 if (t = av_dict_get(st->metadata, "title", NULL, 0))
841 put_ebml_string(pb, MATROSKA_ID_FILEDESC, t->value);
842 if (!(t = av_dict_get(st->metadata, "filename", NULL, 0))) {
843 av_log(s, AV_LOG_ERROR, "Attachment stream %d has no filename tag.\n", i);
844 return AVERROR(EINVAL);
846 put_ebml_string(pb, MATROSKA_ID_FILENAME, t->value);
847 if (t = av_dict_get(st->metadata, "mimetype", NULL, 0))
849 else if (st->codec->codec_id != CODEC_ID_NONE ) {
851 for (i = 0; ff_mkv_mime_tags[i].id != CODEC_ID_NONE; i++)
852 if (ff_mkv_mime_tags[i].id == st->codec->codec_id) {
853 mimetype = ff_mkv_mime_tags[i].str;
858 av_log(s, AV_LOG_ERROR, "Attachment stream %d has no mimetype tag and "
859 "it cannot be deduced from the codec id.\n", i);
860 return AVERROR(EINVAL);
863 put_ebml_string(pb, MATROSKA_ID_FILEMIMETYPE, mimetype);
864 put_ebml_binary(pb, MATROSKA_ID_FILEDATA, st->codec->extradata, st->codec->extradata_size);
865 put_ebml_uint(pb, MATROSKA_ID_FILEUID, av_lfg_get(&c));
866 end_ebml_master(pb, attached_file);
868 end_ebml_master(pb, attachments);
873 static int mkv_write_header(AVFormatContext *s)
875 MatroskaMuxContext *mkv = s->priv_data;
876 AVIOContext *pb = s->pb;
877 ebml_master ebml_header, segment_info;
878 AVDictionaryEntry *tag;
881 if (!strcmp(s->oformat->name, "webm")) mkv->mode = MODE_WEBM;
882 else mkv->mode = MODE_MATROSKAv2;
884 mkv->tracks = av_mallocz(s->nb_streams * sizeof(*mkv->tracks));
886 return AVERROR(ENOMEM);
888 ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
889 put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
890 put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
891 put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
892 put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
893 put_ebml_string (pb, EBML_ID_DOCTYPE , s->oformat->name);
894 put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2);
895 put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2);
896 end_ebml_master(pb, ebml_header);
898 mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
899 mkv->segment_offset = avio_tell(pb);
901 // we write 2 seek heads - one at the end of the file to point to each
902 // cluster, and one at the beginning to point to all other level one
903 // elements (including the seek head at the end of the file), which
904 // isn't more than 10 elements if we only write one of each other
905 // currently defined level 1 element
906 mkv->main_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 10);
907 if (!mkv->main_seekhead)
908 return AVERROR(ENOMEM);
910 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, avio_tell(pb));
911 if (ret < 0) return ret;
913 segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
914 put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
915 if ((tag = av_dict_get(s->metadata, "title", NULL, 0)))
916 put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
917 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
918 uint32_t segment_uid[4];
921 av_lfg_init(&lfg, av_get_random_seed());
923 for (i = 0; i < 4; i++)
924 segment_uid[i] = av_lfg_get(&lfg);
926 put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
927 put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
928 put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
931 // reserve space for the duration
933 mkv->duration_offset = avio_tell(pb);
934 put_ebml_void(pb, 11); // assumes double-precision float to be written
935 end_ebml_master(pb, segment_info);
937 ret = mkv_write_tracks(s);
938 if (ret < 0) return ret;
940 if (mkv->mode != MODE_WEBM) {
941 ret = mkv_write_chapters(s);
942 if (ret < 0) return ret;
944 ret = mkv_write_tags(s);
945 if (ret < 0) return ret;
947 ret = mkv_write_attachments(s);
948 if (ret < 0) return ret;
951 if (!s->pb->seekable)
952 mkv_write_seekhead(pb, mkv->main_seekhead);
954 mkv->cues = mkv_start_cues(mkv->segment_offset);
955 if (mkv->cues == NULL)
956 return AVERROR(ENOMEM);
958 av_init_packet(&mkv->cur_audio_pkt);
959 mkv->cur_audio_pkt.size = 0;
960 mkv->audio_buffer_size = 0;
966 static int mkv_blockgroup_size(int pkt_size)
968 int size = pkt_size + 4;
969 size += ebml_num_size(size);
970 size += 2; // EBML ID for block and block duration
971 size += 8; // max size of block duration
972 size += ebml_num_size(size);
973 size += 1; // blockgroup EBML ID
977 static int ass_get_duration(const uint8_t *p)
979 int sh, sm, ss, sc, eh, em, es, ec;
982 if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
983 &sh, &sm, &ss, &sc, &eh, &em, &es, &ec) != 8)
985 start = 3600000*sh + 60000*sm + 1000*ss + 10*sc;
986 end = 3600000*eh + 60000*em + 1000*es + 10*ec;
990 static int mkv_write_ass_blocks(AVFormatContext *s, AVIOContext *pb, AVPacket *pkt)
992 MatroskaMuxContext *mkv = s->priv_data;
993 int i, layer = 0, max_duration = 0, size, line_size, data_size = pkt->size;
994 uint8_t *start, *end, *data = pkt->data;
995 ebml_master blockgroup;
999 int duration = ass_get_duration(data);
1000 max_duration = FFMAX(duration, max_duration);
1001 end = memchr(data, '\n', data_size);
1002 size = line_size = end ? end-data+1 : data_size;
1003 size -= end ? (end[-1]=='\r')+1 : 0;
1005 for (i=0; i<3; i++, start++)
1006 if (!(start = memchr(start, ',', size-(start-data))))
1007 return max_duration;
1008 size -= start - data;
1009 sscanf(data, "Dialogue: %d,", &layer);
1010 i = snprintf(buffer, sizeof(buffer), "%"PRId64",%d,",
1011 s->streams[pkt->stream_index]->nb_frames, layer);
1012 size = FFMIN(i+size, sizeof(buffer));
1013 memcpy(buffer+i, start, size-i);
1015 av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
1016 "pts %" PRId64 ", duration %d\n",
1017 avio_tell(pb), size, pkt->pts, duration);
1018 blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
1019 put_ebml_id(pb, MATROSKA_ID_BLOCK);
1020 put_ebml_num(pb, size+4, 0);
1021 avio_w8(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
1022 avio_wb16(pb, pkt->pts - mkv->cluster_pts);
1024 avio_write(pb, buffer, size);
1025 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
1026 end_ebml_master(pb, blockgroup);
1029 data_size -= line_size;
1032 return max_duration;
1035 static void mkv_write_block(AVFormatContext *s, AVIOContext *pb,
1036 unsigned int blockid, AVPacket *pkt, int flags)
1038 MatroskaMuxContext *mkv = s->priv_data;
1039 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
1040 uint8_t *data = NULL;
1041 int size = pkt->size;
1042 int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
1044 av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
1045 "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
1046 avio_tell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
1047 if (codec->codec_id == CODEC_ID_H264 && codec->extradata_size > 0 &&
1048 (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
1049 ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
1052 put_ebml_id(pb, blockid);
1053 put_ebml_num(pb, size+4, 0);
1054 avio_w8(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
1055 avio_wb16(pb, ts - mkv->cluster_pts);
1057 avio_write(pb, data, size);
1058 if (data != pkt->data)
1062 static int srt_get_duration(uint8_t **buf)
1064 int i, duration = 0;
1066 for (i=0; i<2 && !duration; i++) {
1067 int s_hour, s_min, s_sec, s_hsec, e_hour, e_min, e_sec, e_hsec;
1068 if (sscanf(*buf, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d",
1069 &s_hour, &s_min, &s_sec, &s_hsec,
1070 &e_hour, &e_min, &e_sec, &e_hsec) == 8) {
1071 s_min += 60*s_hour; e_min += 60*e_hour;
1072 s_sec += 60*s_min; e_sec += 60*e_min;
1073 s_hsec += 1000*s_sec; e_hsec += 1000*e_sec;
1074 duration = e_hsec - s_hsec;
1076 *buf += strcspn(*buf, "\n") + 1;
1081 static int mkv_write_srt_blocks(AVFormatContext *s, AVIOContext *pb, AVPacket *pkt)
1083 ebml_master blockgroup;
1084 AVPacket pkt2 = *pkt;
1085 int64_t duration = srt_get_duration(&pkt2.data);
1086 pkt2.size -= pkt2.data - pkt->data;
1088 blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP,
1089 mkv_blockgroup_size(pkt2.size));
1090 mkv_write_block(s, pb, MATROSKA_ID_BLOCK, &pkt2, 0);
1091 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
1092 end_ebml_master(pb, blockgroup);
1097 static void mkv_flush_dynbuf(AVFormatContext *s)
1099 MatroskaMuxContext *mkv = s->priv_data;
1106 bufsize = avio_close_dyn_buf(mkv->dyn_bc, &dyn_buf);
1107 avio_write(s->pb, dyn_buf, bufsize);
1112 static int mkv_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
1114 MatroskaMuxContext *mkv = s->priv_data;
1115 AVIOContext *pb = s->pb;
1116 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
1117 int keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
1118 int duration = pkt->duration;
1120 int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
1122 if (ts == AV_NOPTS_VALUE) {
1123 av_log(s, AV_LOG_ERROR, "Can't write packet with unknown timestamp\n");
1124 return AVERROR(EINVAL);
1127 if (!s->pb->seekable) {
1129 avio_open_dyn_buf(&mkv->dyn_bc);
1133 if (!mkv->cluster_pos) {
1134 mkv->cluster_pos = avio_tell(s->pb);
1135 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
1136 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, FFMAX(0, ts));
1137 mkv->cluster_pts = FFMAX(0, ts);
1140 if (codec->codec_type != AVMEDIA_TYPE_SUBTITLE) {
1141 mkv_write_block(s, pb, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
1142 } else if (codec->codec_id == CODEC_ID_SSA) {
1143 duration = mkv_write_ass_blocks(s, pb, pkt);
1144 } else if (codec->codec_id == CODEC_ID_SRT) {
1145 duration = mkv_write_srt_blocks(s, pb, pkt);
1147 ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
1148 duration = pkt->convergence_duration;
1149 mkv_write_block(s, pb, MATROSKA_ID_BLOCK, pkt, 0);
1150 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
1151 end_ebml_master(pb, blockgroup);
1154 if (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe) {
1155 ret = mkv_add_cuepoint(mkv->cues, pkt->stream_index, ts, mkv->cluster_pos);
1156 if (ret < 0) return ret;
1159 mkv->duration = FFMAX(mkv->duration, ts + duration);
1163 static int mkv_copy_packet(MatroskaMuxContext *mkv, const AVPacket *pkt)
1165 uint8_t *data = mkv->cur_audio_pkt.data;
1166 mkv->cur_audio_pkt = *pkt;
1167 mkv->cur_audio_pkt.data = av_fast_realloc(data, &mkv->audio_buffer_size, pkt->size);
1168 if (!mkv->cur_audio_pkt.data)
1169 return AVERROR(ENOMEM);
1171 memcpy(mkv->cur_audio_pkt.data, pkt->data, pkt->size);
1172 mkv->cur_audio_pkt.size = pkt->size;
1176 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
1178 MatroskaMuxContext *mkv = s->priv_data;
1179 AVIOContext *pb = s->pb->seekable ? s->pb : mkv->dyn_bc;
1180 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
1181 int ret, keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
1182 int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
1183 int cluster_size = avio_tell(pb) - (s->pb->seekable ? mkv->cluster_pos : 0);
1185 // start a new cluster every 5 MB or 5 sec, or 32k / 1 sec for streaming or
1186 // after 4k and on a keyframe
1187 if (mkv->cluster_pos &&
1188 ((!s->pb->seekable && (cluster_size > 32*1024 || ts > mkv->cluster_pts + 1000))
1189 || cluster_size > 5*1024*1024 || ts > mkv->cluster_pts + 5000
1190 || (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe && cluster_size > 4*1024))) {
1191 av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
1192 " bytes, pts %" PRIu64 "\n", avio_tell(pb), ts);
1193 end_ebml_master(pb, mkv->cluster);
1194 mkv->cluster_pos = 0;
1196 mkv_flush_dynbuf(s);
1199 // check if we have an audio packet cached
1200 if (mkv->cur_audio_pkt.size > 0) {
1201 ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
1202 mkv->cur_audio_pkt.size = 0;
1204 av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
1209 // buffer an audio packet to ensure the packet containing the video
1210 // keyframe's timecode is contained in the same cluster for WebM
1211 if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
1212 ret = mkv_copy_packet(mkv, pkt);
1214 ret = mkv_write_packet_internal(s, pkt);
1218 static int mkv_write_trailer(AVFormatContext *s)
1220 MatroskaMuxContext *mkv = s->priv_data;
1221 AVIOContext *pb = s->pb;
1222 int64_t currentpos, cuespos;
1225 // check if we have an audio packet cached
1226 if (mkv->cur_audio_pkt.size > 0) {
1227 ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
1228 mkv->cur_audio_pkt.size = 0;
1230 av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
1236 end_ebml_master(mkv->dyn_bc, mkv->cluster);
1237 mkv_flush_dynbuf(s);
1238 } else if (mkv->cluster_pos) {
1239 end_ebml_master(pb, mkv->cluster);
1243 if (mkv->cues->num_entries) {
1244 cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
1246 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES, cuespos);
1247 if (ret < 0) return ret;
1250 mkv_write_seekhead(pb, mkv->main_seekhead);
1252 // update the duration
1253 av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
1254 currentpos = avio_tell(pb);
1255 avio_seek(pb, mkv->duration_offset, SEEK_SET);
1256 put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
1258 avio_seek(pb, currentpos, SEEK_SET);
1261 end_ebml_master(pb, mkv->segment);
1262 av_free(mkv->tracks);
1263 av_freep(&mkv->cues->entries);
1264 av_freep(&mkv->cues);
1265 av_destruct_packet(&mkv->cur_audio_pkt);
1270 static int mkv_query_codec(enum CodecID codec_id, int std_compliance)
1273 for (i = 0; ff_mkv_codec_tags[i].id != CODEC_ID_NONE; i++)
1274 if (ff_mkv_codec_tags[i].id == codec_id)
1277 if (std_compliance < FF_COMPLIANCE_NORMAL) { // mkv theoretically supports any
1278 enum AVMediaType type = avcodec_get_type(codec_id); // video/audio through VFW/ACM
1279 if (type == AVMEDIA_TYPE_VIDEO || type == AVMEDIA_TYPE_AUDIO)
1286 #if CONFIG_MATROSKA_MUXER
1287 AVOutputFormat ff_matroska_muxer = {
1289 .long_name = NULL_IF_CONFIG_SMALL("Matroska file format"),
1290 .mime_type = "video/x-matroska",
1291 .extensions = "mkv",
1292 .priv_data_size = sizeof(MatroskaMuxContext),
1293 #if CONFIG_LIBVORBIS_ENCODER
1294 .audio_codec = CODEC_ID_VORBIS,
1296 .audio_codec = CODEC_ID_AC3,
1298 #if CONFIG_LIBX264_ENCODER
1299 .video_codec = CODEC_ID_H264,
1301 .video_codec = CODEC_ID_MPEG4,
1303 .write_header = mkv_write_header,
1304 .write_packet = mkv_write_packet,
1305 .write_trailer = mkv_write_trailer,
1306 .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
1307 .codec_tag = (const AVCodecTag* const []){ff_codec_bmp_tags, ff_codec_wav_tags, 0},
1308 .subtitle_codec = CODEC_ID_SSA,
1309 .query_codec = mkv_query_codec,
1313 #if CONFIG_WEBM_MUXER
1314 AVOutputFormat ff_webm_muxer = {
1316 .long_name = NULL_IF_CONFIG_SMALL("WebM file format"),
1317 .mime_type = "video/webm",
1318 .extensions = "webm",
1319 .priv_data_size = sizeof(MatroskaMuxContext),
1320 .audio_codec = CODEC_ID_VORBIS,
1321 .video_codec = CODEC_ID_VP8,
1322 .write_header = mkv_write_header,
1323 .write_packet = mkv_write_packet,
1324 .write_trailer = mkv_write_trailer,
1325 .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
1329 #if CONFIG_MATROSKA_AUDIO_MUXER
1330 AVOutputFormat ff_matroska_audio_muxer = {
1332 .long_name = NULL_IF_CONFIG_SMALL("Matroska file format"),
1333 .mime_type = "audio/x-matroska",
1334 .extensions = "mka",
1335 .priv_data_size = sizeof(MatroskaMuxContext),
1336 #if CONFIG_LIBVORBIS_ENCODER
1337 .audio_codec = CODEC_ID_VORBIS,
1339 .audio_codec = CODEC_ID_AC3,
1341 .video_codec = CODEC_ID_NONE,
1342 .write_header = mkv_write_header,
1343 .write_packet = mkv_write_packet,
1344 .write_trailer = mkv_write_trailer,
1345 .flags = AVFMT_GLOBALHEADER,
1346 .codec_tag = (const AVCodecTag* const []){ff_codec_wav_tags, 0},