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
29 typedef struct ebml_master {
30 offset_t pos; ///< absolute offset in the file where the master's elements start
31 int sizebytes; ///< how many bytes were reserved for the size
34 typedef struct mkv_seekhead_entry {
35 unsigned int elementid;
39 typedef struct mkv_seekhead {
41 offset_t segment_offset; ///< the file offset to the beginning of the segment
42 int reserved_size; ///< -1 if appending to file
44 mkv_seekhead_entry *entries;
51 offset_t cluster_pos; ///< file offset of the cluster containing the block
55 offset_t segment_offset;
56 mkv_cuepoint *entries;
60 typedef struct MatroskaMuxContext {
62 offset_t segment_offset;
65 offset_t cluster_pos; ///< file offset of the current cluster
67 offset_t duration_offset;
69 mkv_seekhead *main_seekhead;
70 mkv_seekhead *cluster_seekhead;
73 struct AVMD5 *md5_ctx;
77 /** 2 bytes * 3 for EBML IDs, 3 1-byte EBML lengths, 8 bytes for 64 bit
78 * offset, 4 bytes for target EBML ID */
79 #define MAX_SEEKENTRY_SIZE 21
81 /** per-cuepoint-track - 3 1-byte EBML IDs, 3 1-byte EBML sizes, 2
83 #define MAX_CUETRACKPOS_SIZE 22
85 /** per-cuepoint - 2 1-byte EBML IDs, 2 1-byte EBML sizes, 8-byte uint max */
86 #define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
89 static int ebml_id_size(unsigned int id)
91 return (av_log2(id+1)-1)/7+1;
94 static void put_ebml_id(ByteIOContext *pb, unsigned int id)
96 int i = ebml_id_size(id);
98 put_byte(pb, id >> (i*8));
102 * Write an EBML size meaning "unknown size".
104 * @param bytes The number of bytes the size should occupy (maximum: 8).
106 static void put_ebml_size_unknown(ByteIOContext *pb, int bytes)
109 put_byte(pb, 0x1ff >> bytes);
115 * Calculate how many bytes are needed to represent a given number in EBML.
117 static int ebml_num_size(uint64_t num)
120 while ((num+1) >> bytes*7) bytes++;
125 * Write a number in EBML variable length format.
127 * @param bytes The number of bytes that need to be used to write the number.
128 * If zero, any number of bytes can be used.
130 static void put_ebml_num(ByteIOContext *pb, uint64_t num, int bytes)
132 int i, needed_bytes = ebml_num_size(num);
134 // sizes larger than this are currently undefined in EBML
135 assert(num < (1ULL<<56)-1);
138 // don't care how many bytes are used, so use the min
139 bytes = needed_bytes;
140 // the bytes needed to write the given size would exceed the bytes
141 // that we need to use, so write unknown size. This shouldn't happen.
142 assert(bytes >= needed_bytes);
144 num |= 1ULL << bytes*7;
145 for (i = bytes - 1; i >= 0; i--)
146 put_byte(pb, num >> i*8);
149 static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
152 while (val >> bytes*8) bytes++;
154 put_ebml_id(pb, elementid);
155 put_ebml_num(pb, bytes, 0);
156 for (i = bytes - 1; i >= 0; i--)
157 put_byte(pb, val >> i*8);
160 static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
162 put_ebml_id(pb, elementid);
163 put_ebml_num(pb, 8, 0);
164 put_be64(pb, av_dbl2int(val));
167 static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
168 const uint8_t *buf, int size)
170 put_ebml_id(pb, elementid);
171 put_ebml_num(pb, size, 0);
172 put_buffer(pb, buf, size);
175 static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
177 put_ebml_binary(pb, elementid, str, strlen(str));
181 * Writes a void element of a given size. Useful for reserving space in
182 * the file to be written to later.
184 * @param size The number of bytes to reserve, which must be at least 2.
186 static void put_ebml_void(ByteIOContext *pb, uint64_t size)
188 offset_t currentpos = url_ftell(pb);
192 put_ebml_id(pb, EBML_ID_VOID);
193 // we need to subtract the length needed to store the size from the
194 // size we need to reserve so 2 cases, we use 8 bytes to store the
195 // size if possible, 1 byte otherwise
197 put_ebml_num(pb, size-1, 0);
199 put_ebml_num(pb, size-9, 8);
200 url_fseek(pb, currentpos + size, SEEK_SET);
203 static ebml_master start_ebml_master(ByteIOContext *pb, unsigned int elementid, uint64_t expectedsize)
205 int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
206 put_ebml_id(pb, elementid);
207 put_ebml_size_unknown(pb, bytes);
208 return (ebml_master){ url_ftell(pb), bytes };
211 static void end_ebml_master(ByteIOContext *pb, ebml_master master)
213 offset_t pos = url_ftell(pb);
215 // leave the unknown size for masters when streaming
216 if (url_is_streamed(pb))
219 url_fseek(pb, master.pos - master.sizebytes, SEEK_SET);
220 put_ebml_num(pb, pos - master.pos, master.sizebytes);
221 url_fseek(pb, pos, SEEK_SET);
224 static void put_xiph_size(ByteIOContext *pb, int size)
227 for (i = 0; i < size / 255; i++)
229 put_byte(pb, size % 255);
233 * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
234 * elements. If a maximum number of elements is specified, enough space
235 * will be reserved at the current file location to write a seek head of
238 * @param segment_offset The absolute offset to the position in the file
239 * where the segment begins.
240 * @param numelements The maximum number of elements that will be indexed
241 * by this seek head, 0 if unlimited.
243 static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, offset_t segment_offset, int numelements)
245 mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
246 if (new_seekhead == NULL)
249 new_seekhead->segment_offset = segment_offset;
251 if (numelements > 0) {
252 new_seekhead->filepos = url_ftell(pb);
253 // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
254 // and size, and 3 bytes to guarantee that an EBML void element
255 // will fit afterwards
256 new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
257 new_seekhead->max_entries = numelements;
258 put_ebml_void(pb, new_seekhead->reserved_size);
263 static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
265 mkv_seekhead_entry *entries = seekhead->entries;
267 // don't store more elements than we reserved space for
268 if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
271 entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
273 return AVERROR(ENOMEM);
275 entries[seekhead->num_entries ].elementid = elementid;
276 entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
278 seekhead->entries = entries;
283 * Write the seek head to the file and free it. If a maximum number of
284 * elements was specified to mkv_start_seekhead(), the seek head will
285 * be written at the location reserved for it. Otherwise, it is written
286 * at the current location in the file.
288 * @return The file offset where the seekhead was written.
290 static offset_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
292 ebml_master metaseek, seekentry;
296 currentpos = url_ftell(pb);
298 if (seekhead->reserved_size > 0)
299 url_fseek(pb, seekhead->filepos, SEEK_SET);
301 metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
302 for (i = 0; i < seekhead->num_entries; i++) {
303 mkv_seekhead_entry *entry = &seekhead->entries[i];
305 seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
307 put_ebml_id(pb, MATROSKA_ID_SEEKID);
308 put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
309 put_ebml_id(pb, entry->elementid);
311 put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
312 end_ebml_master(pb, seekentry);
314 end_ebml_master(pb, metaseek);
316 if (seekhead->reserved_size > 0) {
317 uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
318 put_ebml_void(pb, remaining);
319 url_fseek(pb, currentpos, SEEK_SET);
321 currentpos = seekhead->filepos;
323 av_free(seekhead->entries);
329 static mkv_cues * mkv_start_cues(offset_t segment_offset)
331 mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
335 cues->segment_offset = segment_offset;
339 static int mkv_add_cuepoint(mkv_cues *cues, AVPacket *pkt, offset_t cluster_pos)
341 mkv_cuepoint *entries = cues->entries;
343 entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
345 return AVERROR(ENOMEM);
347 entries[cues->num_entries ].pts = pkt->pts;
348 entries[cues->num_entries ].tracknum = pkt->stream_index + 1;
349 entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
351 cues->entries = entries;
355 static offset_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues, int num_tracks)
357 ebml_master cues_element;
361 currentpos = url_ftell(pb);
362 cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
364 for (i = 0; i < cues->num_entries; i++) {
365 ebml_master cuepoint, track_positions;
366 mkv_cuepoint *entry = &cues->entries[i];
367 uint64_t pts = entry->pts;
369 cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
370 put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
372 // put all the entries from different tracks that have the exact same
373 // timestamp into the same CuePoint
374 for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
375 track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
376 put_ebml_uint(pb, MATROSKA_ID_CUETRACK , entry[j].tracknum );
377 put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
378 end_ebml_master(pb, track_positions);
381 end_ebml_master(pb, cuepoint);
383 end_ebml_master(pb, cues_element);
385 av_free(cues->entries);
390 static int put_xiph_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
392 uint8_t *header_start[3];
394 int first_header_size;
397 if (codec->codec_id == CODEC_ID_VORBIS)
398 first_header_size = 30;
400 first_header_size = 42;
402 if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
403 first_header_size, header_start, header_len) < 0) {
404 av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
408 put_byte(pb, 2); // number packets - 1
409 for (j = 0; j < 2; j++) {
410 put_xiph_size(pb, header_len[j]);
412 for (j = 0; j < 3; j++)
413 put_buffer(pb, header_start[j], header_len[j]);
418 #define FLAC_STREAMINFO_SIZE 34
420 static int put_flac_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
422 // if the extradata_size is greater than FLAC_STREAMINFO_SIZE,
423 // assume that it's in Matroska's format already
424 if (codec->extradata_size < FLAC_STREAMINFO_SIZE) {
425 av_log(s, AV_LOG_ERROR, "Invalid FLAC extradata\n");
427 } else if (codec->extradata_size == FLAC_STREAMINFO_SIZE) {
428 // only the streaminfo packet
430 put_xiph_size(pb, codec->extradata_size);
431 av_log(s, AV_LOG_ERROR, "Only one packet\n");
433 put_buffer(pb, codec->extradata, codec->extradata_size);
437 static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
439 static const int aac_sample_rates[] = {
440 96000, 88200, 64000, 48000, 44100, 32000,
441 24000, 22050, 16000, 12000, 11025, 8000,
445 if (codec->extradata_size < 2) {
446 av_log(s, AV_LOG_WARNING, "No AAC extradata, unable to determine samplerate.\n");
450 sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
452 av_log(s, AV_LOG_WARNING, "AAC samplerate index out of bounds\n");
455 *sample_rate = aac_sample_rates[sri];
457 // if sbr, get output sample rate as well
458 if (codec->extradata_size == 5) {
459 sri = (codec->extradata[4] >> 3) & 0xF;
461 av_log(s, AV_LOG_WARNING, "AAC output samplerate index out of bounds\n");
464 *output_sample_rate = aac_sample_rates[sri];
468 static int mkv_write_codecprivate(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec, int native_id)
470 ByteIOContext *dyn_cp;
472 int ret, codecpriv_size;
474 ret = url_open_dyn_buf(&dyn_cp);
479 if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA)
480 ret = put_xiph_codecpriv(s, dyn_cp, codec);
481 else if (codec->codec_id == CODEC_ID_FLAC)
482 ret = put_flac_codecpriv(s, dyn_cp, codec);
483 else if (codec->codec_id == CODEC_ID_H264)
484 ret = isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
485 else if (codec->extradata_size)
486 put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
487 } else if (codec->codec_type == CODEC_TYPE_VIDEO) {
488 if (!codec->codec_tag)
489 codec->codec_tag = codec_get_tag(codec_bmp_tags, codec->codec_id);
490 if (!codec->codec_tag) {
491 av_log(s, AV_LOG_ERROR, "No bmp codec ID found.");
495 put_bmp_header(dyn_cp, codec, codec_bmp_tags, 0);
497 } else if (codec->codec_type == CODEC_TYPE_AUDIO) {
498 if (!codec->codec_tag)
499 codec->codec_tag = codec_get_tag(codec_wav_tags, codec->codec_id);
500 if (!codec->codec_tag) {
501 av_log(s, AV_LOG_ERROR, "No wav codec ID found.");
505 put_wav_header(dyn_cp, codec);
508 codecpriv_size = url_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 ByteIOContext *pb = s->pb;
522 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(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;
531 int bit_depth = av_get_bits_per_sample(codec->codec_id);
532 int sample_rate = codec->sample_rate;
533 int output_sample_rate = 0;
536 bit_depth = av_get_bits_per_sample_format(codec->sample_fmt);
538 if (codec->codec_id == CODEC_ID_AAC)
539 get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
541 track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
542 put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
543 put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
544 put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
547 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, st->language);
549 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, "und");
551 // look for a codec ID string specific to mkv to use,
552 // if none are found, use AVI codes
553 for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
554 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
555 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
561 switch (codec->codec_type) {
562 case CODEC_TYPE_VIDEO:
563 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
566 // if there is no mkv-specific codec ID, use VFW mode
567 put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_VIDEO_VFW_FOURCC);
569 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
570 // XXX: interlace flag?
571 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
572 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
573 if (codec->sample_aspect_ratio.num) {
574 AVRational dar = av_mul_q(codec->sample_aspect_ratio,
575 (AVRational){codec->width, codec->height});
576 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , dar.num);
577 put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, dar.den);
579 end_ebml_master(pb, subinfo);
582 case CODEC_TYPE_AUDIO:
583 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
586 // no mkv-specific ID, use ACM mode
587 put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_AUDIO_ACM);
589 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
590 put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
591 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
592 if (output_sample_rate)
593 put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
595 put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
596 end_ebml_master(pb, subinfo);
599 case CODEC_TYPE_SUBTITLE:
600 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
603 av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.");
606 ret = mkv_write_codecprivate(s, pb, codec, native_id);
607 if (ret < 0) return ret;
609 end_ebml_master(pb, track);
611 // ms precision is the de-facto standard timescale for mkv files
612 av_set_pts_info(st, 64, 1, 1000);
614 end_ebml_master(pb, tracks);
618 static int mkv_write_header(AVFormatContext *s)
620 MatroskaMuxContext *mkv = s->priv_data;
621 ByteIOContext *pb = s->pb;
622 ebml_master ebml_header, segment_info;
625 mkv->md5_ctx = av_mallocz(av_md5_size);
626 av_md5_init(mkv->md5_ctx);
628 ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
629 put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
630 put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
631 put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
632 put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
633 put_ebml_string (pb, EBML_ID_DOCTYPE , "matroska");
634 put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2);
635 put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2);
636 end_ebml_master(pb, ebml_header);
638 mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
639 mkv->segment_offset = url_ftell(pb);
641 // we write 2 seek heads - one at the end of the file to point to each
642 // cluster, and one at the beginning to point to all other level one
643 // elements (including the seek head at the end of the file), which
644 // isn't more than 10 elements if we only write one of each other
645 // currently defined level 1 element
646 mkv->main_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 10);
647 mkv->cluster_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 0);
648 if (mkv->main_seekhead == NULL || mkv->cluster_seekhead == NULL)
649 return AVERROR(ENOMEM);
651 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb));
652 if (ret < 0) return ret;
654 segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
655 put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
656 if (strlen(s->title))
657 put_ebml_string(pb, MATROSKA_ID_TITLE, s->title);
658 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
659 put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
660 put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
662 // reserve space to write the segment UID later
663 mkv->segment_uid = url_ftell(pb);
664 put_ebml_void(pb, 19);
667 // reserve space for the duration
669 mkv->duration_offset = url_ftell(pb);
670 put_ebml_void(pb, 11); // assumes double-precision float to be written
671 end_ebml_master(pb, segment_info);
673 ret = mkv_write_tracks(s);
674 if (ret < 0) return ret;
676 ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
677 if (ret < 0) return ret;
679 mkv->cluster_pos = url_ftell(pb);
680 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
681 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0);
682 mkv->cluster_pts = 0;
684 mkv->cues = mkv_start_cues(mkv->segment_offset);
685 if (mkv->cues == NULL)
686 return AVERROR(ENOMEM);
691 static int mkv_block_size(AVPacket *pkt)
693 int size = 4; // track num + timecode + flags
694 return size + pkt->size;
697 static int mkv_blockgroup_size(AVPacket *pkt)
699 int size = mkv_block_size(pkt);
700 size += ebml_num_size(size);
701 size += 2; // EBML ID for block and block duration
702 size += 8; // max size of block duration
703 size += ebml_num_size(size);
704 size += 1; // blockgroup EBML ID
708 static void mkv_write_block(AVFormatContext *s, unsigned int blockid, AVPacket *pkt, int flags)
710 MatroskaMuxContext *mkv = s->priv_data;
711 ByteIOContext *pb = s->pb;
713 av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
714 "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
715 url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
716 put_ebml_id(pb, blockid);
717 put_ebml_num(pb, mkv_block_size(pkt), 0);
718 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
719 put_be16(pb, pkt->pts - mkv->cluster_pts);
721 put_buffer(pb, pkt->data, pkt->size);
724 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
726 MatroskaMuxContext *mkv = s->priv_data;
727 ByteIOContext *pb = s->pb;
728 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
729 int keyframe = !!(pkt->flags & PKT_FLAG_KEY);
732 // start a new cluster every 5 MB or 5 sec
733 if (url_ftell(pb) > mkv->cluster_pos + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) {
734 av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
735 " bytes, pts %" PRIu64 "\n", url_ftell(pb), pkt->pts);
736 end_ebml_master(pb, mkv->cluster);
738 ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
739 if (ret < 0) return ret;
741 mkv->cluster_pos = url_ftell(pb);
742 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
743 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts);
744 mkv->cluster_pts = pkt->pts;
745 av_md5_update(mkv->md5_ctx, pkt->data, FFMIN(200, pkt->size));
748 if (codec->codec_id == CODEC_ID_H264 &&
749 codec->extradata_size > 0 && AV_RB32(codec->extradata) == 0x00000001) {
750 /* from x264 or from bytestream h264 */
751 /* nal reformating needed */
752 int ret = avc_parse_nal_units(pkt->data, &pkt->data, &pkt->size);
758 if (codec->codec_type != CODEC_TYPE_SUBTITLE) {
759 mkv_write_block(s, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
761 ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt));
762 mkv_write_block(s, MATROSKA_ID_BLOCK, pkt, 0);
763 put_ebml_uint(pb, MATROSKA_ID_DURATION, pkt->duration);
764 end_ebml_master(pb, blockgroup);
767 if (codec->codec_type == CODEC_TYPE_VIDEO && keyframe) {
768 ret = mkv_add_cuepoint(mkv->cues, pkt, mkv->cluster_pos);
769 if (ret < 0) return ret;
772 mkv->duration = FFMAX(mkv->duration, pkt->pts + pkt->duration);
776 static int mkv_write_trailer(AVFormatContext *s)
778 MatroskaMuxContext *mkv = s->priv_data;
779 ByteIOContext *pb = s->pb;
780 offset_t currentpos, second_seekhead, cuespos;
783 end_ebml_master(pb, mkv->cluster);
785 if (!url_is_streamed(pb)) {
786 cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
787 second_seekhead = mkv_write_seekhead(pb, mkv->cluster_seekhead);
789 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES , cuespos);
790 if (ret < 0) return ret;
791 ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_SEEKHEAD, second_seekhead);
792 if (ret < 0) return ret;
793 mkv_write_seekhead(pb, mkv->main_seekhead);
795 // update the duration
796 av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
797 currentpos = url_ftell(pb);
798 url_fseek(pb, mkv->duration_offset, SEEK_SET);
799 put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
801 // write the md5sum of some frames as the segment UID
802 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
803 uint8_t segment_uid[16];
804 av_md5_final(mkv->md5_ctx, segment_uid);
805 url_fseek(pb, mkv->segment_uid, SEEK_SET);
806 put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
808 url_fseek(pb, currentpos, SEEK_SET);
811 end_ebml_master(pb, mkv->segment);
812 av_free(mkv->md5_ctx);
816 AVOutputFormat matroska_muxer = {
818 "Matroska File Format",
821 sizeof(MatroskaMuxContext),
827 .codec_tag = (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},
828 .subtitle_codec = CODEC_ID_TEXT,
831 AVOutputFormat matroska_audio_muxer = {
833 "Matroska File Format",
836 sizeof(MatroskaMuxContext),
842 .codec_tag = (const AVCodecTag*[]){codec_wav_tags, 0},