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  1. /*
  2. * Matroska muxer
  3. * Copyright (c) 2007 David Conrad
  4. *
  5. * This file is part of FFmpeg.
  6. *
  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.
  11. *
  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.
  16. *
  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
  20. */
  21. #include "avformat.h"
  22. #include "md5.h"
  23. #include "riff.h"
  24. #include "xiph.h"
  25. #include "matroska.h"
  26. #include "avc.h"
  27. typedef struct ebml_master {
  28. offset_t pos; ///< absolute offset in the file where the master's elements start
  29. int sizebytes; ///< how many bytes were reserved for the size
  30. } ebml_master;
  31. typedef struct mkv_seekhead_entry {
  32. unsigned int elementid;
  33. uint64_t segmentpos;
  34. } mkv_seekhead_entry;
  35. typedef struct mkv_seekhead {
  36. offset_t filepos;
  37. offset_t segment_offset; ///< the file offset to the beginning of the segment
  38. int reserved_size; ///< -1 if appending to file
  39. int max_entries;
  40. mkv_seekhead_entry *entries;
  41. int num_entries;
  42. } mkv_seekhead;
  43. typedef struct {
  44. uint64_t pts;
  45. int tracknum;
  46. offset_t cluster_pos; ///< file offset of the cluster containing the block
  47. } mkv_cuepoint;
  48. typedef struct {
  49. offset_t segment_offset;
  50. mkv_cuepoint *entries;
  51. int num_entries;
  52. } mkv_cues;
  53. typedef struct MatroskaMuxContext {
  54. ebml_master segment;
  55. offset_t segment_offset;
  56. offset_t segment_uid;
  57. ebml_master cluster;
  58. offset_t cluster_pos; ///< file offset of the current cluster
  59. uint64_t cluster_pts;
  60. offset_t duration_offset;
  61. uint64_t duration;
  62. mkv_seekhead *main_seekhead;
  63. mkv_seekhead *cluster_seekhead;
  64. mkv_cues *cues;
  65. struct AVMD5 *md5_ctx;
  66. } MatroskaMuxContext;
  67. /** 2 bytes * 3 for EBML IDs, 3 1-byte EBML lengths, 8 bytes for 64 bit
  68. * offset, 4 bytes for target EBML ID */
  69. #define MAX_SEEKENTRY_SIZE 21
  70. /** per-cuepoint-track - 3 1-byte EBML IDs, 3 1-byte EBML sizes, 2
  71. * 8-byte uint max */
  72. #define MAX_CUETRACKPOS_SIZE 22
  73. /** per-cuepoint - 2 1-byte EBML IDs, 2 1-byte EBML sizes, 8-byte uint max */
  74. #define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
  75. static int ebml_id_size(unsigned int id)
  76. {
  77. return (av_log2(id+1)-1)/7+1;
  78. }
  79. static void put_ebml_id(ByteIOContext *pb, unsigned int id)
  80. {
  81. int i = ebml_id_size(id);
  82. while (i--)
  83. put_byte(pb, id >> (i*8));
  84. }
  85. /**
  86. * Write an EBML size meaning "unknown size".
  87. *
  88. * @param bytes The number of bytes the size should occupy (maximum: 8).
  89. */
  90. static void put_ebml_size_unknown(ByteIOContext *pb, int bytes)
  91. {
  92. assert(bytes <= 8);
  93. put_byte(pb, 0x1ff >> bytes);
  94. while (--bytes)
  95. put_byte(pb, 0xff);
  96. }
  97. /**
  98. * Calculate how many bytes are needed to represent a given number in EBML.
  99. */
  100. static int ebml_num_size(uint64_t num)
  101. {
  102. int bytes = 1;
  103. while ((num+1) >> bytes*7) bytes++;
  104. return bytes;
  105. }
  106. /**
  107. * Write a number in EBML variable length format.
  108. *
  109. * @param bytes The number of bytes that need to be used to write the number.
  110. * If zero, any number of bytes can be used.
  111. */
  112. static void put_ebml_num(ByteIOContext *pb, uint64_t num, int bytes)
  113. {
  114. int i, needed_bytes = ebml_num_size(num);
  115. // sizes larger than this are currently undefined in EBML
  116. assert(num < (1ULL<<56)-1);
  117. if (bytes == 0)
  118. // don't care how many bytes are used, so use the min
  119. bytes = needed_bytes;
  120. // the bytes needed to write the given size would exceed the bytes
  121. // that we need to use, so write unknown size. This shouldn't happen.
  122. assert(bytes >= needed_bytes);
  123. num |= 1ULL << bytes*7;
  124. for (i = bytes - 1; i >= 0; i--)
  125. put_byte(pb, num >> i*8);
  126. }
  127. static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
  128. {
  129. int i, bytes = 1;
  130. while (val >> bytes*8) bytes++;
  131. put_ebml_id(pb, elementid);
  132. put_ebml_num(pb, bytes, 0);
  133. for (i = bytes - 1; i >= 0; i--)
  134. put_byte(pb, val >> i*8);
  135. }
  136. static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
  137. {
  138. put_ebml_id(pb, elementid);
  139. put_ebml_num(pb, 8, 0);
  140. put_be64(pb, av_dbl2int(val));
  141. }
  142. static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
  143. const uint8_t *buf, int size)
  144. {
  145. put_ebml_id(pb, elementid);
  146. put_ebml_num(pb, size, 0);
  147. put_buffer(pb, buf, size);
  148. }
  149. static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
  150. {
  151. put_ebml_binary(pb, elementid, str, strlen(str));
  152. }
  153. /**
  154. * Writes a void element of a given size. Useful for reserving space in
  155. * the file to be written to later.
  156. *
  157. * @param size The number of bytes to reserve, which must be at least 2.
  158. */
  159. static void put_ebml_void(ByteIOContext *pb, uint64_t size)
  160. {
  161. offset_t currentpos = url_ftell(pb);
  162. assert(size >= 2);
  163. put_ebml_id(pb, EBML_ID_VOID);
  164. // we need to subtract the length needed to store the size from the
  165. // size we need to reserve so 2 cases, we use 8 bytes to store the
  166. // size if possible, 1 byte otherwise
  167. if (size < 10)
  168. put_ebml_num(pb, size-1, 0);
  169. else
  170. put_ebml_num(pb, size-9, 8);
  171. while(url_ftell(pb) < currentpos + size)
  172. put_byte(pb, 0);
  173. }
  174. static ebml_master start_ebml_master(ByteIOContext *pb, unsigned int elementid, uint64_t expectedsize)
  175. {
  176. int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
  177. put_ebml_id(pb, elementid);
  178. put_ebml_size_unknown(pb, bytes);
  179. return (ebml_master){ url_ftell(pb), bytes };
  180. }
  181. static void end_ebml_master(ByteIOContext *pb, ebml_master master)
  182. {
  183. offset_t pos = url_ftell(pb);
  184. // leave the unknown size for masters when streaming
  185. if (url_is_streamed(pb))
  186. return;
  187. url_fseek(pb, master.pos - master.sizebytes, SEEK_SET);
  188. put_ebml_num(pb, pos - master.pos, master.sizebytes);
  189. url_fseek(pb, pos, SEEK_SET);
  190. }
  191. static void put_xiph_size(ByteIOContext *pb, int size)
  192. {
  193. int i;
  194. for (i = 0; i < size / 255; i++)
  195. put_byte(pb, 255);
  196. put_byte(pb, size % 255);
  197. }
  198. /**
  199. * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
  200. * elements. If a maximum number of elements is specified, enough space
  201. * will be reserved at the current file location to write a seek head of
  202. * that size.
  203. *
  204. * @param segment_offset The absolute offset to the position in the file
  205. * where the segment begins.
  206. * @param numelements The maximum number of elements that will be indexed
  207. * by this seek head, 0 if unlimited.
  208. */
  209. static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, offset_t segment_offset, int numelements)
  210. {
  211. mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
  212. if (new_seekhead == NULL)
  213. return NULL;
  214. new_seekhead->segment_offset = segment_offset;
  215. if (numelements > 0) {
  216. new_seekhead->filepos = url_ftell(pb);
  217. // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
  218. // and size, and 3 bytes to guarantee that an EBML void element
  219. // will fit afterwards
  220. new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
  221. new_seekhead->max_entries = numelements;
  222. put_ebml_void(pb, new_seekhead->reserved_size);
  223. }
  224. return new_seekhead;
  225. }
  226. static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
  227. {
  228. mkv_seekhead_entry *entries = seekhead->entries;
  229. // don't store more elements than we reserved space for
  230. if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
  231. return -1;
  232. entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
  233. if (entries == NULL)
  234. return AVERROR(ENOMEM);
  235. entries[seekhead->num_entries ].elementid = elementid;
  236. entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
  237. seekhead->entries = entries;
  238. return 0;
  239. }
  240. /**
  241. * Write the seek head to the file and free it. If a maximum number of
  242. * elements was specified to mkv_start_seekhead(), the seek head will
  243. * be written at the location reserved for it. Otherwise, it is written
  244. * at the current location in the file.
  245. *
  246. * @return The file offset where the seekhead was written.
  247. */
  248. static offset_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
  249. {
  250. ebml_master metaseek, seekentry;
  251. offset_t currentpos;
  252. int i;
  253. currentpos = url_ftell(pb);
  254. if (seekhead->reserved_size > 0)
  255. url_fseek(pb, seekhead->filepos, SEEK_SET);
  256. metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
  257. for (i = 0; i < seekhead->num_entries; i++) {
  258. mkv_seekhead_entry *entry = &seekhead->entries[i];
  259. seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
  260. put_ebml_id(pb, MATROSKA_ID_SEEKID);
  261. put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
  262. put_ebml_id(pb, entry->elementid);
  263. put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
  264. end_ebml_master(pb, seekentry);
  265. }
  266. end_ebml_master(pb, metaseek);
  267. if (seekhead->reserved_size > 0) {
  268. uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
  269. put_ebml_void(pb, remaining);
  270. url_fseek(pb, currentpos, SEEK_SET);
  271. currentpos = seekhead->filepos;
  272. }
  273. av_free(seekhead->entries);
  274. av_free(seekhead);
  275. return currentpos;
  276. }
  277. static mkv_cues * mkv_start_cues(offset_t segment_offset)
  278. {
  279. mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
  280. if (cues == NULL)
  281. return NULL;
  282. cues->segment_offset = segment_offset;
  283. return cues;
  284. }
  285. static int mkv_add_cuepoint(mkv_cues *cues, AVPacket *pkt, offset_t cluster_pos)
  286. {
  287. mkv_cuepoint *entries = cues->entries;
  288. entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
  289. if (entries == NULL)
  290. return AVERROR(ENOMEM);
  291. entries[cues->num_entries ].pts = pkt->pts;
  292. entries[cues->num_entries ].tracknum = pkt->stream_index + 1;
  293. entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
  294. cues->entries = entries;
  295. return 0;
  296. }
  297. static offset_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues, int num_tracks)
  298. {
  299. ebml_master cues_element;
  300. offset_t currentpos;
  301. int i, j;
  302. currentpos = url_ftell(pb);
  303. cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
  304. for (i = 0; i < cues->num_entries; i++) {
  305. ebml_master cuepoint, track_positions;
  306. mkv_cuepoint *entry = &cues->entries[i];
  307. uint64_t pts = entry->pts;
  308. cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
  309. put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
  310. // put all the entries from different tracks that have the exact same
  311. // timestamp into the same CuePoint
  312. for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
  313. track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
  314. put_ebml_uint(pb, MATROSKA_ID_CUETRACK , entry[j].tracknum );
  315. put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
  316. end_ebml_master(pb, track_positions);
  317. }
  318. i += j - 1;
  319. end_ebml_master(pb, cuepoint);
  320. }
  321. end_ebml_master(pb, cues_element);
  322. av_free(cues->entries);
  323. av_free(cues);
  324. return currentpos;
  325. }
  326. static int put_xiph_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
  327. {
  328. uint8_t *header_start[3];
  329. int header_len[3];
  330. int first_header_size;
  331. int j;
  332. if (codec->codec_id == CODEC_ID_VORBIS)
  333. first_header_size = 30;
  334. else
  335. first_header_size = 42;
  336. if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
  337. first_header_size, header_start, header_len) < 0) {
  338. av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
  339. return -1;
  340. }
  341. put_byte(pb, 2); // number packets - 1
  342. for (j = 0; j < 2; j++) {
  343. put_xiph_size(pb, header_len[j]);
  344. }
  345. for (j = 0; j < 3; j++)
  346. put_buffer(pb, header_start[j], header_len[j]);
  347. return 0;
  348. }
  349. #define FLAC_STREAMINFO_SIZE 34
  350. static int put_flac_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
  351. {
  352. // if the extradata_size is greater than FLAC_STREAMINFO_SIZE,
  353. // assume that it's in Matroska's format already
  354. if (codec->extradata_size < FLAC_STREAMINFO_SIZE) {
  355. av_log(s, AV_LOG_ERROR, "Invalid FLAC extradata\n");
  356. return -1;
  357. } else if (codec->extradata_size == FLAC_STREAMINFO_SIZE) {
  358. // only the streaminfo packet
  359. put_byte(pb, 0);
  360. put_xiph_size(pb, codec->extradata_size);
  361. av_log(s, AV_LOG_ERROR, "Only one packet\n");
  362. }
  363. put_buffer(pb, codec->extradata, codec->extradata_size);
  364. return 0;
  365. }
  366. static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
  367. {
  368. static const int aac_sample_rates[] = {
  369. 96000, 88200, 64000, 48000, 44100, 32000,
  370. 24000, 22050, 16000, 12000, 11025, 8000,
  371. };
  372. int sri;
  373. if (codec->extradata_size < 2) {
  374. av_log(s, AV_LOG_WARNING, "No AAC extradata, unable to determine samplerate.\n");
  375. return;
  376. }
  377. sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
  378. if (sri > 12) {
  379. av_log(s, AV_LOG_WARNING, "AAC samplerate index out of bounds\n");
  380. return;
  381. }
  382. *sample_rate = aac_sample_rates[sri];
  383. // if sbr, get output sample rate as well
  384. if (codec->extradata_size == 5) {
  385. sri = (codec->extradata[4] >> 3) & 0xF;
  386. if (sri > 12) {
  387. av_log(s, AV_LOG_WARNING, "AAC output samplerate index out of bounds\n");
  388. return;
  389. }
  390. *output_sample_rate = aac_sample_rates[sri];
  391. }
  392. }
  393. static int mkv_write_codecprivate(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec, int native_id)
  394. {
  395. ByteIOContext *dyn_cp;
  396. uint8_t *codecpriv;
  397. int ret, codecpriv_size;
  398. ret = url_open_dyn_buf(&dyn_cp);
  399. if(ret < 0)
  400. return ret;
  401. if (native_id) {
  402. if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA)
  403. ret = put_xiph_codecpriv(s, dyn_cp, codec);
  404. else if (codec->codec_id == CODEC_ID_FLAC)
  405. ret = put_flac_codecpriv(s, dyn_cp, codec);
  406. else if (codec->codec_id == CODEC_ID_H264)
  407. ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
  408. else if (codec->extradata_size)
  409. put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
  410. } else if (codec->codec_type == CODEC_TYPE_VIDEO) {
  411. if (!codec->codec_tag)
  412. codec->codec_tag = codec_get_tag(codec_bmp_tags, codec->codec_id);
  413. if (!codec->codec_tag) {
  414. av_log(s, AV_LOG_ERROR, "No bmp codec ID found.");
  415. ret = -1;
  416. }
  417. put_bmp_header(dyn_cp, codec, codec_bmp_tags, 0);
  418. } else if (codec->codec_type == CODEC_TYPE_AUDIO) {
  419. if (!codec->codec_tag)
  420. codec->codec_tag = codec_get_tag(codec_wav_tags, codec->codec_id);
  421. if (!codec->codec_tag) {
  422. av_log(s, AV_LOG_ERROR, "No wav codec ID found.");
  423. ret = -1;
  424. }
  425. put_wav_header(dyn_cp, codec);
  426. }
  427. codecpriv_size = url_close_dyn_buf(dyn_cp, &codecpriv);
  428. if (codecpriv_size)
  429. put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
  430. av_free(codecpriv);
  431. return ret;
  432. }
  433. static int mkv_write_tracks(AVFormatContext *s)
  434. {
  435. MatroskaMuxContext *mkv = s->priv_data;
  436. ByteIOContext *pb = s->pb;
  437. ebml_master tracks;
  438. int i, j, ret;
  439. ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb));
  440. if (ret < 0) return ret;
  441. tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
  442. for (i = 0; i < s->nb_streams; i++) {
  443. AVStream *st = s->streams[i];
  444. AVCodecContext *codec = st->codec;
  445. ebml_master subinfo, track;
  446. int native_id = 0;
  447. int bit_depth = av_get_bits_per_sample(codec->codec_id);
  448. int sample_rate = codec->sample_rate;
  449. int output_sample_rate = 0;
  450. if (!bit_depth)
  451. bit_depth = av_get_bits_per_sample_format(codec->sample_fmt);
  452. if (codec->codec_id == CODEC_ID_AAC)
  453. get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
  454. track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
  455. put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
  456. put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
  457. put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
  458. if (st->language[0])
  459. put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, st->language);
  460. else
  461. put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, "und");
  462. // look for a codec ID string specific to mkv to use,
  463. // if none are found, use AVI codes
  464. for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
  465. if (ff_mkv_codec_tags[j].id == codec->codec_id) {
  466. put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
  467. native_id = 1;
  468. break;
  469. }
  470. }
  471. switch (codec->codec_type) {
  472. case CODEC_TYPE_VIDEO:
  473. put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
  474. if (!native_id)
  475. // if there is no mkv-specific codec ID, use VFW mode
  476. put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_VIDEO_VFW_FOURCC);
  477. subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
  478. // XXX: interlace flag?
  479. put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
  480. put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
  481. if (codec->sample_aspect_ratio.num) {
  482. AVRational dar = av_mul_q(codec->sample_aspect_ratio,
  483. (AVRational){codec->width, codec->height});
  484. put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , dar.num);
  485. put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, dar.den);
  486. }
  487. end_ebml_master(pb, subinfo);
  488. break;
  489. case CODEC_TYPE_AUDIO:
  490. put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
  491. if (!native_id)
  492. // no mkv-specific ID, use ACM mode
  493. put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_AUDIO_ACM);
  494. subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
  495. put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
  496. put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
  497. if (output_sample_rate)
  498. put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
  499. if (bit_depth)
  500. put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
  501. end_ebml_master(pb, subinfo);
  502. break;
  503. case CODEC_TYPE_SUBTITLE:
  504. put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
  505. break;
  506. default:
  507. av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.");
  508. break;
  509. }
  510. ret = mkv_write_codecprivate(s, pb, codec, native_id);
  511. if (ret < 0) return ret;
  512. end_ebml_master(pb, track);
  513. // ms precision is the de-facto standard timescale for mkv files
  514. av_set_pts_info(st, 64, 1, 1000);
  515. }
  516. end_ebml_master(pb, tracks);
  517. return 0;
  518. }
  519. static int mkv_write_header(AVFormatContext *s)
  520. {
  521. MatroskaMuxContext *mkv = s->priv_data;
  522. ByteIOContext *pb = s->pb;
  523. ebml_master ebml_header, segment_info;
  524. int ret;
  525. mkv->md5_ctx = av_mallocz(av_md5_size);
  526. av_md5_init(mkv->md5_ctx);
  527. ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
  528. put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
  529. put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
  530. put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
  531. put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
  532. put_ebml_string (pb, EBML_ID_DOCTYPE , "matroska");
  533. put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2);
  534. put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2);
  535. end_ebml_master(pb, ebml_header);
  536. mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
  537. mkv->segment_offset = url_ftell(pb);
  538. // we write 2 seek heads - one at the end of the file to point to each
  539. // cluster, and one at the beginning to point to all other level one
  540. // elements (including the seek head at the end of the file), which
  541. // isn't more than 10 elements if we only write one of each other
  542. // currently defined level 1 element
  543. mkv->main_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 10);
  544. mkv->cluster_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 0);
  545. if (mkv->main_seekhead == NULL || mkv->cluster_seekhead == NULL)
  546. return AVERROR(ENOMEM);
  547. ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb));
  548. if (ret < 0) return ret;
  549. segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
  550. put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
  551. if (strlen(s->title))
  552. put_ebml_string(pb, MATROSKA_ID_TITLE, s->title);
  553. if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
  554. put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
  555. put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
  556. // reserve space to write the segment UID later
  557. mkv->segment_uid = url_ftell(pb);
  558. put_ebml_void(pb, 19);
  559. }
  560. // reserve space for the duration
  561. mkv->duration = 0;
  562. mkv->duration_offset = url_ftell(pb);
  563. put_ebml_void(pb, 11); // assumes double-precision float to be written
  564. end_ebml_master(pb, segment_info);
  565. ret = mkv_write_tracks(s);
  566. if (ret < 0) return ret;
  567. ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
  568. if (ret < 0) return ret;
  569. mkv->cluster_pos = url_ftell(pb);
  570. mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
  571. put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0);
  572. mkv->cluster_pts = 0;
  573. mkv->cues = mkv_start_cues(mkv->segment_offset);
  574. if (mkv->cues == NULL)
  575. return AVERROR(ENOMEM);
  576. return 0;
  577. }
  578. static int mkv_block_size(AVPacket *pkt)
  579. {
  580. int size = 4; // track num + timecode + flags
  581. return size + pkt->size;
  582. }
  583. static int mkv_blockgroup_size(AVPacket *pkt)
  584. {
  585. int size = mkv_block_size(pkt);
  586. size += ebml_num_size(size);
  587. size += 2; // EBML ID for block and block duration
  588. size += 8; // max size of block duration
  589. size += ebml_num_size(size);
  590. size += 1; // blockgroup EBML ID
  591. return size;
  592. }
  593. static void mkv_write_block(AVFormatContext *s, unsigned int blockid, AVPacket *pkt, int flags)
  594. {
  595. MatroskaMuxContext *mkv = s->priv_data;
  596. ByteIOContext *pb = s->pb;
  597. av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
  598. "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
  599. url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
  600. put_ebml_id(pb, blockid);
  601. put_ebml_num(pb, mkv_block_size(pkt), 0);
  602. put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
  603. put_be16(pb, pkt->pts - mkv->cluster_pts);
  604. put_byte(pb, flags);
  605. put_buffer(pb, pkt->data, pkt->size);
  606. }
  607. static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
  608. {
  609. MatroskaMuxContext *mkv = s->priv_data;
  610. ByteIOContext *pb = s->pb;
  611. AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
  612. int keyframe = !!(pkt->flags & PKT_FLAG_KEY);
  613. int ret;
  614. // start a new cluster every 5 MB or 5 sec
  615. if (url_ftell(pb) > mkv->cluster_pos + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) {
  616. av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
  617. " bytes, pts %" PRIu64 "\n", url_ftell(pb), pkt->pts);
  618. end_ebml_master(pb, mkv->cluster);
  619. ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
  620. if (ret < 0) return ret;
  621. mkv->cluster_pos = url_ftell(pb);
  622. mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
  623. put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts);
  624. mkv->cluster_pts = pkt->pts;
  625. av_md5_update(mkv->md5_ctx, pkt->data, FFMIN(200, pkt->size));
  626. }
  627. if (codec->codec_id == CODEC_ID_H264 &&
  628. codec->extradata_size > 0 && AV_RB32(codec->extradata) == 0x00000001) {
  629. /* from x264 or from bytestream h264 */
  630. /* nal reformating needed */
  631. int ret = ff_avc_parse_nal_units(pkt->data, &pkt->data, &pkt->size);
  632. if (ret < 0)
  633. return ret;
  634. assert(pkt->size);
  635. }
  636. if (codec->codec_type != CODEC_TYPE_SUBTITLE) {
  637. mkv_write_block(s, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
  638. } else {
  639. ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt));
  640. mkv_write_block(s, MATROSKA_ID_BLOCK, pkt, 0);
  641. put_ebml_uint(pb, MATROSKA_ID_DURATION, pkt->duration);
  642. end_ebml_master(pb, blockgroup);
  643. }
  644. if (codec->codec_type == CODEC_TYPE_VIDEO && keyframe) {
  645. ret = mkv_add_cuepoint(mkv->cues, pkt, mkv->cluster_pos);
  646. if (ret < 0) return ret;
  647. }
  648. mkv->duration = FFMAX(mkv->duration, pkt->pts + pkt->duration);
  649. return 0;
  650. }
  651. static int mkv_write_trailer(AVFormatContext *s)
  652. {
  653. MatroskaMuxContext *mkv = s->priv_data;
  654. ByteIOContext *pb = s->pb;
  655. offset_t currentpos, second_seekhead, cuespos;
  656. int ret;
  657. end_ebml_master(pb, mkv->cluster);
  658. if (!url_is_streamed(pb)) {
  659. cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
  660. second_seekhead = mkv_write_seekhead(pb, mkv->cluster_seekhead);
  661. ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES , cuespos);
  662. if (ret < 0) return ret;
  663. ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_SEEKHEAD, second_seekhead);
  664. if (ret < 0) return ret;
  665. mkv_write_seekhead(pb, mkv->main_seekhead);
  666. // update the duration
  667. av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
  668. currentpos = url_ftell(pb);
  669. url_fseek(pb, mkv->duration_offset, SEEK_SET);
  670. put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
  671. // write the md5sum of some frames as the segment UID
  672. if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
  673. uint8_t segment_uid[16];
  674. av_md5_final(mkv->md5_ctx, segment_uid);
  675. url_fseek(pb, mkv->segment_uid, SEEK_SET);
  676. put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
  677. }
  678. url_fseek(pb, currentpos, SEEK_SET);
  679. }
  680. end_ebml_master(pb, mkv->segment);
  681. av_free(mkv->md5_ctx);
  682. return 0;
  683. }
  684. AVOutputFormat matroska_muxer = {
  685. "matroska",
  686. "Matroska File Format",
  687. "video/x-matroska",
  688. "mkv",
  689. sizeof(MatroskaMuxContext),
  690. CODEC_ID_MP2,
  691. CODEC_ID_MPEG4,
  692. mkv_write_header,
  693. mkv_write_packet,
  694. mkv_write_trailer,
  695. .codec_tag = (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},
  696. .subtitle_codec = CODEC_ID_TEXT,
  697. };
  698. AVOutputFormat matroska_audio_muxer = {
  699. "matroska",
  700. "Matroska File Format",
  701. "audio/x-matroska",
  702. "mka",
  703. sizeof(MatroskaMuxContext),
  704. CODEC_ID_MP2,
  705. CODEC_ID_NONE,
  706. mkv_write_header,
  707. mkv_write_packet,
  708. mkv_write_trailer,
  709. .codec_tag = (const AVCodecTag*[]){codec_wav_tags, 0},
  710. };