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/random_seed.h"
30 #include "libavutil/lfg.h"
31 #include "libavcodec/xiph.h"
32 #include "libavcodec/mpeg4audio.h"
34 typedef struct ebml_master {
35 int64_t pos; ///< absolute offset in the file where the master's elements start
36 int sizebytes; ///< how many bytes were reserved for the size
39 typedef struct mkv_seekhead_entry {
40 unsigned int elementid;
44 typedef struct mkv_seekhead {
46 int64_t segment_offset; ///< the file offset to the beginning of the segment
47 int reserved_size; ///< -1 if appending to file
49 mkv_seekhead_entry *entries;
56 int64_t cluster_pos; ///< file offset of the cluster containing the block
60 int64_t segment_offset;
61 mkv_cuepoint *entries;
69 #define MODE_MATROSKAv2 0x01
70 #define MODE_WEBM 0x02
72 typedef struct MatroskaMuxContext {
74 ByteIOContext *dyn_bc;
76 int64_t segment_offset;
78 int64_t cluster_pos; ///< file offset of the current cluster
80 int64_t duration_offset;
82 mkv_seekhead *main_seekhead;
86 unsigned int audio_buffer_size;
87 AVPacket cur_audio_pkt;
91 /** 2 bytes * 3 for EBML IDs, 3 1-byte EBML lengths, 8 bytes for 64 bit
92 * offset, 4 bytes for target EBML ID */
93 #define MAX_SEEKENTRY_SIZE 21
95 /** per-cuepoint-track - 3 1-byte EBML IDs, 3 1-byte EBML sizes, 2
97 #define MAX_CUETRACKPOS_SIZE 22
99 /** per-cuepoint - 2 1-byte EBML IDs, 2 1-byte EBML sizes, 8-byte uint max */
100 #define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
103 static int ebml_id_size(unsigned int id)
105 return (av_log2(id+1)-1)/7+1;
108 static void put_ebml_id(ByteIOContext *pb, unsigned int id)
110 int i = ebml_id_size(id);
112 put_byte(pb, id >> (i*8));
116 * Write an EBML size meaning "unknown size".
118 * @param bytes The number of bytes the size should occupy (maximum: 8).
120 static void put_ebml_size_unknown(ByteIOContext *pb, int bytes)
123 put_byte(pb, 0x1ff >> bytes);
129 * Calculate how many bytes are needed to represent a given number in EBML.
131 static int ebml_num_size(uint64_t num)
134 while ((num+1) >> bytes*7) bytes++;
139 * Write a number in EBML variable length format.
141 * @param bytes The number of bytes that need to be used to write the number.
142 * If zero, any number of bytes can be used.
144 static void put_ebml_num(ByteIOContext *pb, uint64_t num, int bytes)
146 int i, needed_bytes = ebml_num_size(num);
148 // sizes larger than this are currently undefined in EBML
149 assert(num < (1ULL<<56)-1);
152 // don't care how many bytes are used, so use the min
153 bytes = needed_bytes;
154 // the bytes needed to write the given size would exceed the bytes
155 // that we need to use, so write unknown size. This shouldn't happen.
156 assert(bytes >= needed_bytes);
158 num |= 1ULL << bytes*7;
159 for (i = bytes - 1; i >= 0; i--)
160 put_byte(pb, num >> i*8);
163 static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
167 while (tmp>>=8) bytes++;
169 put_ebml_id(pb, elementid);
170 put_ebml_num(pb, bytes, 0);
171 for (i = bytes - 1; i >= 0; i--)
172 put_byte(pb, val >> i*8);
175 static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
177 put_ebml_id(pb, elementid);
178 put_ebml_num(pb, 8, 0);
179 put_be64(pb, av_dbl2int(val));
182 static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
183 const void *buf, int size)
185 put_ebml_id(pb, elementid);
186 put_ebml_num(pb, size, 0);
187 put_buffer(pb, buf, size);
190 static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
192 put_ebml_binary(pb, elementid, str, strlen(str));
196 * Writes a void element of a given size. Useful for reserving space in
197 * the file to be written to later.
199 * @param size The number of bytes to reserve, which must be at least 2.
201 static void put_ebml_void(ByteIOContext *pb, uint64_t size)
203 int64_t currentpos = url_ftell(pb);
207 put_ebml_id(pb, EBML_ID_VOID);
208 // we need to subtract the length needed to store the size from the
209 // size we need to reserve so 2 cases, we use 8 bytes to store the
210 // size if possible, 1 byte otherwise
212 put_ebml_num(pb, size-1, 0);
214 put_ebml_num(pb, size-9, 8);
215 while(url_ftell(pb) < currentpos + size)
219 static ebml_master start_ebml_master(ByteIOContext *pb, unsigned int elementid, uint64_t expectedsize)
221 int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
222 put_ebml_id(pb, elementid);
223 put_ebml_size_unknown(pb, bytes);
224 return (ebml_master){ url_ftell(pb), bytes };
227 static void end_ebml_master(ByteIOContext *pb, ebml_master master)
229 int64_t pos = url_ftell(pb);
231 if (url_fseek(pb, master.pos - master.sizebytes, SEEK_SET) < 0)
233 put_ebml_num(pb, pos - master.pos, master.sizebytes);
234 url_fseek(pb, pos, SEEK_SET);
237 static void put_xiph_size(ByteIOContext *pb, int size)
240 for (i = 0; i < size / 255; i++)
242 put_byte(pb, size % 255);
246 * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
247 * elements. If a maximum number of elements is specified, enough space
248 * will be reserved at the current file location to write a seek head of
251 * @param segment_offset The absolute offset to the position in the file
252 * where the segment begins.
253 * @param numelements The maximum number of elements that will be indexed
254 * by this seek head, 0 if unlimited.
256 static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, int64_t segment_offset, int numelements)
258 mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
259 if (new_seekhead == NULL)
262 new_seekhead->segment_offset = segment_offset;
264 if (numelements > 0) {
265 new_seekhead->filepos = url_ftell(pb);
266 // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
267 // and size, and 3 bytes to guarantee that an EBML void element
268 // will fit afterwards
269 new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
270 new_seekhead->max_entries = numelements;
271 put_ebml_void(pb, new_seekhead->reserved_size);
276 static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
278 mkv_seekhead_entry *entries = seekhead->entries;
280 // don't store more elements than we reserved space for
281 if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
284 entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
286 return AVERROR(ENOMEM);
288 entries[seekhead->num_entries ].elementid = elementid;
289 entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
291 seekhead->entries = entries;
296 * Write the seek head to the file and free it. If a maximum number of
297 * elements was specified to mkv_start_seekhead(), the seek head will
298 * be written at the location reserved for it. Otherwise, it is written
299 * at the current location in the file.
301 * @return The file offset where the seekhead was written,
302 * -1 if an error occurred.
304 static int64_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
306 ebml_master metaseek, seekentry;
310 currentpos = url_ftell(pb);
312 if (seekhead->reserved_size > 0)
313 if (url_fseek(pb, seekhead->filepos, SEEK_SET) < 0)
316 metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
317 for (i = 0; i < seekhead->num_entries; i++) {
318 mkv_seekhead_entry *entry = &seekhead->entries[i];
320 seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
322 put_ebml_id(pb, MATROSKA_ID_SEEKID);
323 put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
324 put_ebml_id(pb, entry->elementid);
326 put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
327 end_ebml_master(pb, seekentry);
329 end_ebml_master(pb, metaseek);
331 if (seekhead->reserved_size > 0) {
332 uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
333 put_ebml_void(pb, remaining);
334 url_fseek(pb, currentpos, SEEK_SET);
336 currentpos = seekhead->filepos;
338 av_free(seekhead->entries);
344 static mkv_cues * mkv_start_cues(int64_t segment_offset)
346 mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
350 cues->segment_offset = segment_offset;
354 static int mkv_add_cuepoint(mkv_cues *cues, int stream, int64_t ts, int64_t cluster_pos)
356 mkv_cuepoint *entries = cues->entries;
358 entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
360 return AVERROR(ENOMEM);
365 entries[cues->num_entries ].pts = ts;
366 entries[cues->num_entries ].tracknum = stream + 1;
367 entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
369 cues->entries = entries;
373 static int64_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues, int num_tracks)
375 ebml_master cues_element;
379 currentpos = url_ftell(pb);
380 cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
382 for (i = 0; i < cues->num_entries; i++) {
383 ebml_master cuepoint, track_positions;
384 mkv_cuepoint *entry = &cues->entries[i];
385 uint64_t pts = entry->pts;
387 cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
388 put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
390 // put all the entries from different tracks that have the exact same
391 // timestamp into the same CuePoint
392 for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
393 track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
394 put_ebml_uint(pb, MATROSKA_ID_CUETRACK , entry[j].tracknum );
395 put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
396 end_ebml_master(pb, track_positions);
399 end_ebml_master(pb, cuepoint);
401 end_ebml_master(pb, cues_element);
403 av_free(cues->entries);
408 static int put_xiph_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
410 uint8_t *header_start[3];
412 int first_header_size;
415 if (codec->codec_id == CODEC_ID_VORBIS)
416 first_header_size = 30;
418 first_header_size = 42;
420 if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
421 first_header_size, header_start, header_len) < 0) {
422 av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
426 put_byte(pb, 2); // number packets - 1
427 for (j = 0; j < 2; j++) {
428 put_xiph_size(pb, header_len[j]);
430 for (j = 0; j < 3; j++)
431 put_buffer(pb, header_start[j], header_len[j]);
436 static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
440 if (codec->extradata_size < 2) {
441 av_log(s, AV_LOG_WARNING, "No AAC extradata, unable to determine samplerate.\n");
445 sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
447 av_log(s, AV_LOG_WARNING, "AAC samplerate index out of bounds\n");
450 *sample_rate = ff_mpeg4audio_sample_rates[sri];
452 // if sbr, get output sample rate as well
453 if (codec->extradata_size == 5) {
454 sri = (codec->extradata[4] >> 3) & 0xF;
456 av_log(s, AV_LOG_WARNING, "AAC output samplerate index out of bounds\n");
459 *output_sample_rate = ff_mpeg4audio_sample_rates[sri];
463 static int mkv_write_codecprivate(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec, int native_id, int qt_id)
465 ByteIOContext *dyn_cp;
467 int ret, codecpriv_size;
469 ret = url_open_dyn_buf(&dyn_cp);
474 if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA)
475 ret = put_xiph_codecpriv(s, dyn_cp, codec);
476 else if (codec->codec_id == CODEC_ID_FLAC)
477 ret = ff_flac_write_header(dyn_cp, codec, 1);
478 else if (codec->codec_id == CODEC_ID_H264)
479 ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
480 else if (codec->extradata_size)
481 put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
482 } else if (codec->codec_type == AVMEDIA_TYPE_VIDEO) {
484 if (!codec->codec_tag)
485 codec->codec_tag = ff_codec_get_tag(codec_movvideo_tags, codec->codec_id);
486 if (codec->extradata_size)
487 put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
489 if (!codec->codec_tag)
490 codec->codec_tag = ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id);
491 if (!codec->codec_tag) {
492 av_log(s, AV_LOG_ERROR, "No bmp codec ID found.\n");
496 ff_put_bmp_header(dyn_cp, codec, ff_codec_bmp_tags, 0);
499 } else if (codec->codec_type == AVMEDIA_TYPE_AUDIO) {
501 tag = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);
503 av_log(s, AV_LOG_ERROR, "No wav codec ID found.\n");
506 if (!codec->codec_tag)
507 codec->codec_tag = tag;
509 ff_put_wav_header(dyn_cp, codec);
512 codecpriv_size = url_close_dyn_buf(dyn_cp, &codecpriv);
514 put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
519 static int mkv_write_tracks(AVFormatContext *s)
521 MatroskaMuxContext *mkv = s->priv_data;
522 ByteIOContext *pb = s->pb;
526 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb));
527 if (ret < 0) return ret;
529 tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
530 for (i = 0; i < s->nb_streams; i++) {
531 AVStream *st = s->streams[i];
532 AVCodecContext *codec = st->codec;
533 ebml_master subinfo, track;
536 int bit_depth = av_get_bits_per_sample(codec->codec_id);
537 int sample_rate = codec->sample_rate;
538 int output_sample_rate = 0;
542 bit_depth = av_get_bits_per_sample_format(codec->sample_fmt);
544 if (codec->codec_id == CODEC_ID_AAC)
545 get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
547 track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
548 put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
549 put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
550 put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
552 if ((tag = av_metadata_get(st->metadata, "title", NULL, 0)))
553 put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
554 tag = av_metadata_get(st->metadata, "language", NULL, 0);
555 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
558 put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
560 // look for a codec ID string specific to mkv to use,
561 // if none are found, use AVI codes
562 for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
563 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
564 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
570 if (mkv->mode == MODE_WEBM && !(codec->codec_id == CODEC_ID_VP8 ||
571 codec->codec_id == CODEC_ID_VORBIS)) {
572 av_log(s, AV_LOG_ERROR,
573 "Only VP8 video and Vorbis audio are supported for WebM.\n");
574 return AVERROR(EINVAL);
577 switch (codec->codec_type) {
578 case AVMEDIA_TYPE_VIDEO:
579 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
580 put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, av_q2d(codec->time_base)*1E9);
583 ff_codec_get_tag(codec_movvideo_tags, codec->codec_id) &&
584 (!ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id)
585 || codec->codec_id == CODEC_ID_SVQ1
586 || codec->codec_id == CODEC_ID_SVQ3
587 || codec->codec_id == CODEC_ID_CINEPAK))
591 put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
592 else if (!native_id) {
593 // if there is no mkv-specific codec ID, use VFW mode
594 put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
595 mkv->tracks[i].write_dts = 1;
598 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
599 // XXX: interlace flag?
600 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
601 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
602 if (st->sample_aspect_ratio.num) {
603 int d_width = codec->width*av_q2d(st->sample_aspect_ratio);
604 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width);
605 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height);
607 end_ebml_master(pb, subinfo);
610 case AVMEDIA_TYPE_AUDIO:
611 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
614 // no mkv-specific ID, use ACM mode
615 put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
617 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
618 put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
619 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
620 if (output_sample_rate)
621 put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
623 put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
624 end_ebml_master(pb, subinfo);
627 case AVMEDIA_TYPE_SUBTITLE:
628 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
631 av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.");
634 ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
635 if (ret < 0) return ret;
637 end_ebml_master(pb, track);
639 // ms precision is the de-facto standard timescale for mkv files
640 av_set_pts_info(st, 64, 1, 1000);
642 end_ebml_master(pb, tracks);
646 static int mkv_write_chapters(AVFormatContext *s)
648 MatroskaMuxContext *mkv = s->priv_data;
649 ByteIOContext *pb = s->pb;
650 ebml_master chapters, editionentry;
651 AVRational scale = {1, 1E9};
657 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CHAPTERS, url_ftell(pb));
658 if (ret < 0) return ret;
660 chapters = start_ebml_master(pb, MATROSKA_ID_CHAPTERS , 0);
661 editionentry = start_ebml_master(pb, MATROSKA_ID_EDITIONENTRY, 0);
662 put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGDEFAULT, 1);
663 put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGHIDDEN , 0);
664 for (i = 0; i < s->nb_chapters; i++) {
665 ebml_master chapteratom, chapterdisplay;
666 AVChapter *c = s->chapters[i];
667 AVMetadataTag *t = NULL;
669 chapteratom = start_ebml_master(pb, MATROSKA_ID_CHAPTERATOM, 0);
670 put_ebml_uint(pb, MATROSKA_ID_CHAPTERUID, c->id);
671 put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMESTART,
672 av_rescale_q(c->start, c->time_base, scale));
673 put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMEEND,
674 av_rescale_q(c->end, c->time_base, scale));
675 put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGHIDDEN , 0);
676 put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGENABLED, 1);
677 if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {
678 chapterdisplay = start_ebml_master(pb, MATROSKA_ID_CHAPTERDISPLAY, 0);
679 put_ebml_string(pb, MATROSKA_ID_CHAPSTRING, t->value);
680 put_ebml_string(pb, MATROSKA_ID_CHAPLANG , "und");
681 end_ebml_master(pb, chapterdisplay);
683 end_ebml_master(pb, chapteratom);
685 end_ebml_master(pb, editionentry);
686 end_ebml_master(pb, chapters);
690 static int mkv_write_header(AVFormatContext *s)
692 MatroskaMuxContext *mkv = s->priv_data;
693 ByteIOContext *pb = s->pb;
694 ebml_master ebml_header, segment_info;
698 if (!strcmp(s->oformat->name, "webm")) mkv->mode = MODE_WEBM;
699 else mkv->mode = MODE_MATROSKAv2;
701 mkv->tracks = av_mallocz(s->nb_streams * sizeof(*mkv->tracks));
703 return AVERROR(ENOMEM);
705 ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
706 put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
707 put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
708 put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
709 put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
710 put_ebml_string (pb, EBML_ID_DOCTYPE , s->oformat->name);
711 put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2);
712 put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2);
713 end_ebml_master(pb, ebml_header);
715 mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
716 mkv->segment_offset = url_ftell(pb);
718 // we write 2 seek heads - one at the end of the file to point to each
719 // cluster, and one at the beginning to point to all other level one
720 // elements (including the seek head at the end of the file), which
721 // isn't more than 10 elements if we only write one of each other
722 // currently defined level 1 element
723 mkv->main_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 10);
724 if (!mkv->main_seekhead)
725 return AVERROR(ENOMEM);
727 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb));
728 if (ret < 0) return ret;
730 segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
731 put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
732 if ((tag = av_metadata_get(s->metadata, "title", NULL, 0)))
733 put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
734 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
735 uint32_t segment_uid[4];
738 av_lfg_init(&lfg, av_get_random_seed());
740 for (i = 0; i < 4; i++)
741 segment_uid[i] = av_lfg_get(&lfg);
743 put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
744 put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
745 put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
748 // reserve space for the duration
750 mkv->duration_offset = url_ftell(pb);
751 put_ebml_void(pb, 11); // assumes double-precision float to be written
752 end_ebml_master(pb, segment_info);
754 ret = mkv_write_tracks(s);
755 if (ret < 0) return ret;
757 if (mkv->mode != MODE_WEBM) {
758 ret = mkv_write_chapters(s);
759 if (ret < 0) return ret;
762 if (url_is_streamed(s->pb))
763 mkv_write_seekhead(pb, mkv->main_seekhead);
765 mkv->cues = mkv_start_cues(mkv->segment_offset);
766 if (mkv->cues == NULL)
767 return AVERROR(ENOMEM);
769 av_init_packet(&mkv->cur_audio_pkt);
770 mkv->cur_audio_pkt.size = 0;
771 mkv->audio_buffer_size = 0;
773 put_flush_packet(pb);
777 static int mkv_blockgroup_size(int pkt_size)
779 int size = pkt_size + 4;
780 size += ebml_num_size(size);
781 size += 2; // EBML ID for block and block duration
782 size += 8; // max size of block duration
783 size += ebml_num_size(size);
784 size += 1; // blockgroup EBML ID
788 static int ass_get_duration(const uint8_t *p)
790 int sh, sm, ss, sc, eh, em, es, ec;
793 if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
794 &sh, &sm, &ss, &sc, &eh, &em, &es, &ec) != 8)
796 start = 3600000*sh + 60000*sm + 1000*ss + 10*sc;
797 end = 3600000*eh + 60000*em + 1000*es + 10*ec;
801 static int mkv_write_ass_blocks(AVFormatContext *s, ByteIOContext *pb, AVPacket *pkt)
803 MatroskaMuxContext *mkv = s->priv_data;
804 int i, layer = 0, max_duration = 0, size, line_size, data_size = pkt->size;
805 uint8_t *start, *end, *data = pkt->data;
806 ebml_master blockgroup;
810 int duration = ass_get_duration(data);
811 max_duration = FFMAX(duration, max_duration);
812 end = memchr(data, '\n', data_size);
813 size = line_size = end ? end-data+1 : data_size;
814 size -= end ? (end[-1]=='\r')+1 : 0;
816 for (i=0; i<3; i++, start++)
817 if (!(start = memchr(start, ',', size-(start-data))))
819 size -= start - data;
820 sscanf(data, "Dialogue: %d,", &layer);
821 i = snprintf(buffer, sizeof(buffer), "%"PRId64",%d,",
822 s->streams[pkt->stream_index]->nb_frames++, layer);
823 size = FFMIN(i+size, sizeof(buffer));
824 memcpy(buffer+i, start, size-i);
826 av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
827 "pts %" PRId64 ", duration %d\n",
828 url_ftell(pb), size, pkt->pts, duration);
829 blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
830 put_ebml_id(pb, MATROSKA_ID_BLOCK);
831 put_ebml_num(pb, size+4, 0);
832 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
833 put_be16(pb, pkt->pts - mkv->cluster_pts);
835 put_buffer(pb, buffer, size);
836 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
837 end_ebml_master(pb, blockgroup);
840 data_size -= line_size;
846 static void mkv_write_block(AVFormatContext *s, ByteIOContext *pb,
847 unsigned int blockid, AVPacket *pkt, int flags)
849 MatroskaMuxContext *mkv = s->priv_data;
850 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
851 uint8_t *data = NULL;
852 int size = pkt->size;
853 int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
855 av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
856 "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
857 url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
858 if (codec->codec_id == CODEC_ID_H264 && codec->extradata_size > 0 &&
859 (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
860 ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
863 put_ebml_id(pb, blockid);
864 put_ebml_num(pb, size+4, 0);
865 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
866 put_be16(pb, ts - mkv->cluster_pts);
868 put_buffer(pb, data, size);
869 if (data != pkt->data)
873 static void mkv_flush_dynbuf(AVFormatContext *s)
875 MatroskaMuxContext *mkv = s->priv_data;
882 bufsize = url_close_dyn_buf(mkv->dyn_bc, &dyn_buf);
883 put_buffer(s->pb, dyn_buf, bufsize);
888 static int mkv_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
890 MatroskaMuxContext *mkv = s->priv_data;
891 ByteIOContext *pb = s->pb;
892 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
893 int keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
894 int duration = pkt->duration;
896 int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
898 if (ts == AV_NOPTS_VALUE) {
899 av_log(s, AV_LOG_ERROR, "Can't write packet with unknown timestamp\n");
900 return AVERROR(EINVAL);
903 if (url_is_streamed(s->pb)) {
905 url_open_dyn_buf(&mkv->dyn_bc);
909 if (!mkv->cluster_pos) {
910 mkv->cluster_pos = url_ftell(s->pb);
911 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
912 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, FFMAX(0, ts));
913 mkv->cluster_pts = FFMAX(0, ts);
916 if (codec->codec_type != AVMEDIA_TYPE_SUBTITLE) {
917 mkv_write_block(s, pb, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
918 } else if (codec->codec_id == CODEC_ID_SSA) {
919 duration = mkv_write_ass_blocks(s, pb, pkt);
921 ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
922 duration = pkt->convergence_duration;
923 mkv_write_block(s, pb, MATROSKA_ID_BLOCK, pkt, 0);
924 put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
925 end_ebml_master(pb, blockgroup);
928 if (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe) {
929 ret = mkv_add_cuepoint(mkv->cues, pkt->stream_index, ts, mkv->cluster_pos);
930 if (ret < 0) return ret;
933 mkv->duration = FFMAX(mkv->duration, ts + duration);
937 static int mkv_copy_packet(MatroskaMuxContext *mkv, const AVPacket *pkt)
939 uint8_t *data = mkv->cur_audio_pkt.data;
940 mkv->cur_audio_pkt = *pkt;
941 mkv->cur_audio_pkt.data = av_fast_realloc(data, &mkv->audio_buffer_size, pkt->size);
942 if (!mkv->cur_audio_pkt.data)
943 return AVERROR(ENOMEM);
945 memcpy(mkv->cur_audio_pkt.data, pkt->data, pkt->size);
946 mkv->cur_audio_pkt.size = pkt->size;
950 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
952 MatroskaMuxContext *mkv = s->priv_data;
953 ByteIOContext *pb = url_is_streamed(s->pb) ? mkv->dyn_bc : s->pb;
954 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
955 int ret, keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
956 int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
957 int cluster_size = url_ftell(pb) - (url_is_streamed(s->pb) ? 0 : mkv->cluster_pos);
959 // start a new cluster every 5 MB or 5 sec, or 32k / 1 sec for streaming or
960 // after 4k and on a keyframe
961 if (mkv->cluster_pos &&
962 ((url_is_streamed(s->pb) && (cluster_size > 32*1024 || ts > mkv->cluster_pts + 1000))
963 || cluster_size > 5*1024*1024 || ts > mkv->cluster_pts + 5000
964 || (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe && cluster_size > 4*1024))) {
965 av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
966 " bytes, pts %" PRIu64 "\n", url_ftell(pb), ts);
967 end_ebml_master(pb, mkv->cluster);
968 mkv->cluster_pos = 0;
973 // check if we have an audio packet cached
974 if (mkv->cur_audio_pkt.size > 0) {
975 ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
976 mkv->cur_audio_pkt.size = 0;
978 av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
983 // buffer an audio packet to ensure the packet containing the video
984 // keyframe's timecode is contained in the same cluster for WebM
985 if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
986 ret = mkv_copy_packet(mkv, pkt);
988 ret = mkv_write_packet_internal(s, pkt);
992 static int mkv_write_trailer(AVFormatContext *s)
994 MatroskaMuxContext *mkv = s->priv_data;
995 ByteIOContext *pb = s->pb;
996 int64_t currentpos, cuespos;
999 // check if we have an audio packet cached
1000 if (mkv->cur_audio_pkt.size > 0) {
1001 ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
1002 mkv->cur_audio_pkt.size = 0;
1004 av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
1010 end_ebml_master(mkv->dyn_bc, mkv->cluster);
1011 mkv_flush_dynbuf(s);
1012 } else if (mkv->cluster_pos) {
1013 end_ebml_master(pb, mkv->cluster);
1016 if (!url_is_streamed(pb)) {
1017 cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
1019 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES , cuespos);
1020 if (ret < 0) return ret;
1021 mkv_write_seekhead(pb, mkv->main_seekhead);
1023 // update the duration
1024 av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
1025 currentpos = url_ftell(pb);
1026 url_fseek(pb, mkv->duration_offset, SEEK_SET);
1027 put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
1029 url_fseek(pb, currentpos, SEEK_SET);
1032 end_ebml_master(pb, mkv->segment);
1033 av_free(mkv->tracks);
1034 av_destruct_packet(&mkv->cur_audio_pkt);
1035 put_flush_packet(pb);
1039 #if CONFIG_MATROSKA_MUXER
1040 AVOutputFormat matroska_muxer = {
1042 NULL_IF_CONFIG_SMALL("Matroska file format"),
1045 sizeof(MatroskaMuxContext),
1051 .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
1052 .codec_tag = (const AVCodecTag* const []){ff_codec_bmp_tags, ff_codec_wav_tags, 0},
1053 .subtitle_codec = CODEC_ID_TEXT,
1057 #if CONFIG_WEBM_MUXER
1058 AVOutputFormat webm_muxer = {
1060 NULL_IF_CONFIG_SMALL("WebM file format"),
1063 sizeof(MatroskaMuxContext),
1069 .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
1073 #if CONFIG_MATROSKA_AUDIO_MUXER
1074 AVOutputFormat matroska_audio_muxer = {
1076 NULL_IF_CONFIG_SMALL("Matroska file format"),
1079 sizeof(MatroskaMuxContext),
1085 .flags = AVFMT_GLOBALHEADER,
1086 .codec_tag = (const AVCodecTag* const []){ff_codec_wav_tags, 0},